diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 7889b52afa141..872f916f4cf05 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -202,7 +202,6 @@ check-web-wasm:
     - time cargo web build -p substrate-keystore
     - time cargo web build -p substrate-executor
     - time cargo web build -p substrate-network
-    - time cargo web build -p substrate-offchain
     - time cargo web build -p substrate-panic-handler
     - time cargo web build -p substrate-peerset
     - time cargo web build -p substrate-primitives
@@ -336,7 +335,7 @@ check_warnings:
     - docker push $CONTAINER_IMAGE:$VERSION
     - docker push $CONTAINER_IMAGE:latest
 
-publish-docker-substrate:          
+publish-docker-substrate:
   stage:                           publish
   <<:                              *publish-docker-release
   # collect VERSION artifact here to pass it on to kubernetes
diff --git a/Cargo.lock b/Cargo.lock
index 1c6a4f19231f8..b1936f4177091 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -211,11 +211,6 @@ name = "bitmask"
 version = "0.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
-[[package]]
-name = "bitvec"
-version = "0.11.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-
 [[package]]
 name = "bitvec"
 version = "0.14.0"
@@ -865,7 +860,7 @@ dependencies = [
  "hashmap_core 0.1.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "num-traits 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -917,7 +912,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 name = "fork-tree"
 version = "2.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -1322,6 +1317,18 @@ dependencies = [
  "want 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "hyper-tls"
+version = "0.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "bytes 0.4.12 (registry+https://github.com/rust-lang/crates.io-index)",
+ "futures 0.1.28 (registry+https://github.com/rust-lang/crates.io-index)",
+ "hyper 0.12.33 (registry+https://github.com/rust-lang/crates.io-index)",
+ "native-tls 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "tokio-io 0.1.12 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "idna"
 version = "0.1.5"
@@ -1332,12 +1339,22 @@ dependencies = [
  "unicode-normalization 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "idna"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "matches 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)",
+ "unicode-bidi 0.3.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "unicode-normalization 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "impl-codec"
 version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -1409,24 +1426,25 @@ dependencies = [
 
 [[package]]
 name = "jsonrpc-client-transports"
-version = "13.0.0"
+version = "13.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "failure 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures 0.1.28 (registry+https://github.com/rust-lang/crates.io-index)",
  "hyper 0.12.33 (registry+https://github.com/rust-lang/crates.io-index)",
- "jsonrpc-core 13.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "jsonrpc-pubsub 13.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "jsonrpc-core 13.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "jsonrpc-pubsub 13.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_json 1.0.40 (registry+https://github.com/rust-lang/crates.io-index)",
  "tokio 0.1.22 (registry+https://github.com/rust-lang/crates.io-index)",
+ "url 1.7.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "websocket 0.23.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "jsonrpc-core"
-version = "13.0.0"
+version = "13.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "futures 0.1.28 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1438,15 +1456,15 @@ dependencies = [
 
 [[package]]
 name = "jsonrpc-core-client"
-version = "13.0.0"
+version = "13.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "jsonrpc-client-transports 13.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "jsonrpc-client-transports 13.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "jsonrpc-derive"
-version = "13.0.0"
+version = "13.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "proc-macro-crate 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1457,12 +1475,12 @@ dependencies = [
 
 [[package]]
 name = "jsonrpc-http-server"
-version = "13.0.0"
+version = "13.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "hyper 0.12.33 (registry+https://github.com/rust-lang/crates.io-index)",
- "jsonrpc-core 13.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "jsonrpc-server-utils 13.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "jsonrpc-core 13.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "jsonrpc-server-utils 13.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "net2 0.2.33 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1471,10 +1489,10 @@ dependencies = [
 
 [[package]]
 name = "jsonrpc-pubsub"
-version = "13.0.0"
+version = "13.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "jsonrpc-core 13.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "jsonrpc-core 13.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1482,12 +1500,12 @@ dependencies = [
 
 [[package]]
 name = "jsonrpc-server-utils"
-version = "13.0.0"
+version = "13.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "bytes 0.4.12 (registry+https://github.com/rust-lang/crates.io-index)",
  "globset 0.4.4 (registry+https://github.com/rust-lang/crates.io-index)",
- "jsonrpc-core 13.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "jsonrpc-core 13.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "num_cpus 1.10.1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1498,15 +1516,15 @@ dependencies = [
 
 [[package]]
 name = "jsonrpc-ws-server"
-version = "13.0.0"
+version = "13.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "jsonrpc-core 13.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "jsonrpc-server-utils 13.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "jsonrpc-core 13.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "jsonrpc-server-utils 13.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "slab 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "ws 0.8.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "ws 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -1652,7 +1670,7 @@ dependencies = [
  "lazy_static 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "libsecp256k1 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
- "multistream-select 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "multistream-select 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "parity-multiaddr 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "parity-multihash 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2220,7 +2238,7 @@ dependencies = [
 
 [[package]]
 name = "multistream-select"
-version = "0.5.0"
+version = "0.5.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "bytes 0.4.12 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2286,13 +2304,13 @@ dependencies = [
  "futures 0.1.28 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures-preview 0.3.0-alpha.17 (registry+https://github.com/rust-lang/crates.io-index)",
  "hex-literal 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "jsonrpc-core 13.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "jsonrpc-core 13.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "node-executor 2.0.0",
  "node-primitives 2.0.0",
  "node-rpc 2.0.0",
  "node-runtime 2.0.0",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
  "sr-primitives 2.0.0",
@@ -2336,7 +2354,7 @@ dependencies = [
  "node-primitives 2.0.0",
  "node-runtime 2.0.0",
  "node-testing 2.0.0",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
  "sr-primitives 2.0.0",
  "srml-balances 2.0.0",
@@ -2361,7 +2379,7 @@ dependencies = [
 name = "node-primitives"
 version = "2.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "pretty_assertions 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-primitives 2.0.0",
@@ -2376,15 +2394,15 @@ name = "node-rpc"
 version = "2.0.0"
 dependencies = [
  "env_logger 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "jsonrpc-core 13.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "jsonrpc-core-client 13.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "jsonrpc-derive 13.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "jsonrpc-pubsub 13.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "jsonrpc-core 13.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "jsonrpc-core-client 13.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "jsonrpc-derive 13.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "jsonrpc-pubsub 13.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "node-primitives 2.0.0",
  "node-runtime 2.0.0",
  "node-testing 2.0.0",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-primitives 2.0.0",
  "substrate-client 2.0.0",
@@ -2400,7 +2418,7 @@ dependencies = [
  "env_logger 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures 0.1.28 (registry+https://github.com/rust-lang/crates.io-index)",
  "hyper 0.12.33 (registry+https://github.com/rust-lang/crates.io-index)",
- "jsonrpc-core-client 13.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "jsonrpc-core-client 13.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "node-primitives 2.0.0",
  "substrate-rpc 2.0.0",
@@ -2412,7 +2430,7 @@ version = "2.0.0"
 dependencies = [
  "integer-sqrt 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "node-primitives 2.0.0",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc-hex 2.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "safe-mix 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2462,7 +2480,7 @@ dependencies = [
  "futures 0.1.28 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "node-template-runtime 2.0.0",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
  "substrate-basic-authorship 2.0.0",
@@ -2487,7 +2505,7 @@ dependencies = [
 name = "node-template-runtime"
 version = "2.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "safe-mix 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
@@ -2518,7 +2536,7 @@ dependencies = [
  "node-executor 2.0.0",
  "node-primitives 2.0.0",
  "node-runtime 2.0.0",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
  "sr-primitives 2.0.0",
  "srml-balances 2.0.0",
@@ -2684,16 +2702,6 @@ name = "parity-bytes"
 version = "0.1.0"
 source = "git+https://github.com/paritytech/parity-common?rev=b0317f649ab2c665b7987b8475878fc4d2e1f81d#b0317f649ab2c665b7987b8475878fc4d2e1f81d"
 
-[[package]]
-name = "parity-codec"
-version = "4.1.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "arrayvec 0.4.11 (registry+https://github.com/rust-lang/crates.io-index)",
- "bitvec 0.11.3 (registry+https://github.com/rust-lang/crates.io-index)",
- "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
 [[package]]
 name = "parity-multiaddr"
 version = "0.5.0"
@@ -2727,7 +2735,7 @@ dependencies = [
 
 [[package]]
 name = "parity-scale-codec"
-version = "1.0.4"
+version = "1.0.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "arrayvec 0.4.11 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2735,7 +2743,6 @@ dependencies = [
  "byte-slice-cast 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "parity-scale-codec-derive 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
- "vecarray 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -2922,6 +2929,11 @@ name = "percent-encoding"
 version = "1.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "percent-encoding"
+version = "2.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "pin-utils"
 version = "0.1.0-alpha.4"
@@ -3288,7 +3300,7 @@ dependencies = [
  "error-chain 0.12.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures 0.1.28 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -3680,7 +3692,7 @@ version = "2.0.0"
 dependencies = [
  "blake2-rfc 0.2.18 (registry+https://github.com/rust-lang/crates.io-index)",
  "criterion 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "proc-macro-crate 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "proc-macro2 0.4.30 (registry+https://github.com/rust-lang/crates.io-index)",
  "quote 0.6.13 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -3702,7 +3714,7 @@ dependencies = [
  "environmental 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "hash-db 0.15.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "libsecp256k1 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc_version 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-std 2.0.0",
  "substrate-offchain 2.0.0",
@@ -3719,7 +3731,7 @@ dependencies = [
  "integer-sqrt 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "num-traits 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "paste 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "primitive-types 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -3736,7 +3748,7 @@ name = "sr-sandbox"
 version = "2.0.0"
 dependencies = [
  "assert_matches 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc_version 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-std 2.0.0",
  "substrate-primitives 2.0.0",
@@ -3748,7 +3760,7 @@ dependencies = [
 name = "sr-staking-primitives"
 version = "2.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-primitives 2.0.0",
  "sr-std 2.0.0",
 ]
@@ -3765,7 +3777,7 @@ name = "sr-version"
 version = "2.0.0"
 dependencies = [
  "impl-serde 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-primitives 2.0.0",
  "sr-std 2.0.0",
@@ -3775,7 +3787,7 @@ dependencies = [
 name = "srml-assets"
 version = "2.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
  "sr-primitives 2.0.0",
@@ -3790,7 +3802,7 @@ name = "srml-aura"
 version = "2.0.0"
 dependencies = [
  "lazy_static 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
@@ -3810,10 +3822,11 @@ dependencies = [
 name = "srml-authority-discovery"
 version = "0.1.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
  "sr-primitives 2.0.0",
+ "sr-staking-primitives 2.0.0",
  "sr-std 2.0.0",
  "srml-im-online 0.1.0",
  "srml-session 2.0.0",
@@ -3827,7 +3840,7 @@ dependencies = [
 name = "srml-authorship"
 version = "0.1.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
  "sr-primitives 2.0.0",
  "sr-std 2.0.0",
@@ -3843,7 +3856,7 @@ version = "2.0.0"
 dependencies = [
  "hex-literal 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
@@ -3863,7 +3876,7 @@ dependencies = [
 name = "srml-balances"
 version = "2.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "safe-mix 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
@@ -3880,7 +3893,7 @@ name = "srml-collective"
 version = "2.0.0"
 dependencies = [
  "hex-literal 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "safe-mix 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
@@ -3899,7 +3912,7 @@ dependencies = [
  "assert_matches 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "hex 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "hex-literal 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "parity-wasm 0.31.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "pwasm-utils 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -3920,7 +3933,7 @@ dependencies = [
 name = "srml-democracy"
 version = "2.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "safe-mix 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
@@ -3937,7 +3950,7 @@ name = "srml-elections"
 version = "2.0.0"
 dependencies = [
  "hex-literal 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "safe-mix 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
@@ -3953,10 +3966,11 @@ dependencies = [
 name = "srml-example"
 version = "2.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
  "sr-primitives 2.0.0",
+ "sr-std 2.0.0",
  "srml-balances 2.0.0",
  "srml-support 2.0.0",
  "srml-system 2.0.0",
@@ -3968,7 +3982,7 @@ name = "srml-executive"
 version = "2.0.0"
 dependencies = [
  "hex-literal 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
  "sr-primitives 2.0.0",
@@ -3984,7 +3998,7 @@ dependencies = [
 name = "srml-finality-tracker"
 version = "2.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
  "sr-primitives 2.0.0",
@@ -3999,7 +4013,7 @@ dependencies = [
 name = "srml-generic-asset"
 version = "2.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
  "sr-primitives 2.0.0",
@@ -4013,7 +4027,7 @@ dependencies = [
 name = "srml-grandpa"
 version = "2.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
  "sr-primitives 2.0.0",
@@ -4031,7 +4045,7 @@ dependencies = [
 name = "srml-im-online"
 version = "0.1.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
  "sr-primitives 2.0.0",
@@ -4048,7 +4062,7 @@ dependencies = [
 name = "srml-indices"
 version = "2.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "ref_thread_local 0.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "safe-mix 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -4065,7 +4079,7 @@ dependencies = [
 name = "srml-membership"
 version = "2.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
  "sr-primitives 2.0.0",
@@ -4079,7 +4093,7 @@ dependencies = [
 name = "srml-metadata"
 version = "2.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-std 2.0.0",
  "substrate-primitives 2.0.0",
@@ -4089,7 +4103,7 @@ dependencies = [
 name = "srml-offences"
 version = "1.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
  "sr-primitives 2.0.0",
@@ -4105,7 +4119,7 @@ dependencies = [
 name = "srml-scored-pool"
 version = "1.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
  "sr-primitives 2.0.0",
@@ -4121,7 +4135,7 @@ name = "srml-session"
 version = "2.0.0"
 dependencies = [
  "lazy_static 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "safe-mix 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
@@ -4140,7 +4154,7 @@ dependencies = [
 name = "srml-staking"
 version = "2.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "safe-mix 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -4162,7 +4176,7 @@ dependencies = [
 name = "srml-sudo"
 version = "2.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
  "sr-primitives 2.0.0",
@@ -4179,7 +4193,7 @@ version = "2.0.0"
 dependencies = [
  "bitmask 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "once_cell 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "paste 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "pretty_assertions 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -4228,7 +4242,7 @@ dependencies = [
 name = "srml-support-test"
 version = "2.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "pretty_assertions 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
@@ -4243,7 +4257,7 @@ name = "srml-system"
 version = "2.0.0"
 dependencies = [
  "criterion 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "safe-mix 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
@@ -4258,7 +4272,7 @@ dependencies = [
 name = "srml-timestamp"
 version = "2.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
  "sr-primitives 2.0.0",
@@ -4273,7 +4287,7 @@ dependencies = [
 name = "srml-treasury"
 version = "2.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
  "sr-primitives 2.0.0",
@@ -4365,7 +4379,7 @@ dependencies = [
  "hex-literal 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "node-primitives 2.0.0",
  "node-runtime 2.0.0",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc-hex 2.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-primitives 2.0.0",
@@ -4390,7 +4404,7 @@ dependencies = [
 name = "substrate-application-crypto"
 version = "2.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
  "sr-primitives 2.0.0",
@@ -4403,7 +4417,7 @@ dependencies = [
 name = "substrate-authority-discovery-primitives"
 version = "2.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-primitives 2.0.0",
  "sr-std 2.0.0",
  "substrate-client 2.0.0",
@@ -4415,7 +4429,7 @@ version = "2.0.0"
 dependencies = [
  "futures-preview 0.3.0-alpha.17 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-primitives 2.0.0",
  "substrate-client 2.0.0",
  "substrate-consensus-common 2.0.0",
@@ -4485,7 +4499,7 @@ dependencies = [
  "kvdb 0.1.0 (git+https://github.com/paritytech/parity-common?rev=b0317f649ab2c665b7987b8475878fc4d2e1f81d)",
  "kvdb-memorydb 0.1.0 (git+https://github.com/paritytech/parity-common?rev=b0317f649ab2c665b7987b8475878fc4d2e1f81d)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-api-macros 2.0.0",
  "sr-primitives 2.0.0",
@@ -4514,7 +4528,7 @@ dependencies = [
  "kvdb-rocksdb 0.1.4 (git+https://github.com/paritytech/parity-common?rev=b0317f649ab2c665b7987b8475878fc4d2e1f81d)",
  "linked-hash-map 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-primitives 2.0.0",
  "substrate-client 2.0.0",
@@ -4537,7 +4551,7 @@ dependencies = [
  "futures-preview 0.3.0-alpha.17 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures-timer 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
  "sr-primitives 2.0.0",
@@ -4566,7 +4580,7 @@ dependencies = [
 name = "substrate-consensus-aura-primitives"
 version = "2.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-primitives 2.0.0",
  "sr-std 2.0.0",
  "substrate-application-crypto 2.0.0",
@@ -4587,7 +4601,7 @@ dependencies = [
  "num-bigint 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "num-rational 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "num-traits 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "schnorrkel 0.8.4 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -4619,7 +4633,7 @@ dependencies = [
 name = "substrate-consensus-babe-primitives"
 version = "2.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "schnorrkel 0.8.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-primitives 2.0.0",
  "sr-std 2.0.0",
@@ -4637,7 +4651,7 @@ dependencies = [
  "futures-timer 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "libp2p 0.12.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-primitives 2.0.0",
  "sr-std 2.0.0",
@@ -4655,7 +4669,7 @@ dependencies = [
  "exit-future 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures 0.1.28 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rhododendron 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
@@ -4678,7 +4692,7 @@ dependencies = [
  "futures-preview 0.3.0-alpha.17 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures-timer 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-primitives 2.0.0",
  "substrate-client 2.0.0",
@@ -4713,7 +4727,7 @@ dependencies = [
  "lazy_static 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "libsecp256k1 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "parity-wasm 0.31.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
@@ -4741,7 +4755,7 @@ dependencies = [
  "futures 0.1.28 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures-preview 0.3.0-alpha.17 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_json 1.0.40 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -4756,7 +4770,6 @@ dependencies = [
  "substrate-keystore 2.0.0",
  "substrate-network 2.0.0",
  "substrate-primitives 2.0.0",
- "substrate-service 2.0.0",
  "substrate-telemetry 2.0.0",
  "substrate-test-runtime-client 2.0.0",
  "tempfile 3.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -4769,7 +4782,7 @@ dependencies = [
 name = "substrate-finality-grandpa-primitives"
 version = "2.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-primitives 2.0.0",
  "sr-std 2.0.0",
@@ -4781,7 +4794,7 @@ dependencies = [
 name = "substrate-inherents"
 version = "2.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-primitives 2.0.0",
  "sr-std 2.0.0",
@@ -4833,7 +4846,7 @@ dependencies = [
  "linked_hash_set 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "lru-cache 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "quickcheck 0.8.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -4865,11 +4878,18 @@ dependencies = [
 name = "substrate-offchain"
 version = "2.0.0"
 dependencies = [
+ "bytes 0.4.12 (registry+https://github.com/rust-lang/crates.io-index)",
  "env_logger 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "fnv 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "futures 0.1.28 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures-preview 0.3.0-alpha.17 (registry+https://github.com/rust-lang/crates.io-index)",
+ "futures-timer 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "hyper 0.12.33 (registry+https://github.com/rust-lang/crates.io-index)",
+ "hyper-tls 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-primitives 2.0.0",
  "substrate-client 2.0.0",
  "substrate-client-db 2.0.0",
@@ -4879,6 +4899,7 @@ dependencies = [
  "substrate-primitives 2.0.0",
  "substrate-test-runtime-client 2.0.0",
  "substrate-transaction-pool 2.0.0",
+ "tokio 0.1.22 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -4925,8 +4946,9 @@ dependencies = [
  "hex-literal 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "impl-serde 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "num-traits 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "pretty_assertions 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "primitive-types 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -4953,12 +4975,12 @@ dependencies = [
  "derive_more 0.14.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures 0.1.28 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures-preview 0.3.0-alpha.17 (registry+https://github.com/rust-lang/crates.io-index)",
- "jsonrpc-core 13.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "jsonrpc-core-client 13.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "jsonrpc-derive 13.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "jsonrpc-pubsub 13.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "jsonrpc-core 13.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "jsonrpc-core-client 13.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "jsonrpc-derive 13.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "jsonrpc-pubsub 13.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc-hex 2.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -4967,7 +4989,6 @@ dependencies = [
  "sr-primitives 2.0.0",
  "sr-version 2.0.0",
  "substrate-client 2.0.0",
- "substrate-executor 2.0.0",
  "substrate-keystore 2.0.0",
  "substrate-network 2.0.0",
  "substrate-primitives 2.0.0",
@@ -4982,10 +5003,10 @@ dependencies = [
 name = "substrate-rpc-servers"
 version = "2.0.0"
 dependencies = [
- "jsonrpc-core 13.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "jsonrpc-http-server 13.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "jsonrpc-pubsub 13.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "jsonrpc-ws-server 13.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "jsonrpc-core 13.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "jsonrpc-http-server 13.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "jsonrpc-pubsub 13.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "jsonrpc-ws-server 13.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-primitives 2.0.0",
@@ -5024,7 +5045,7 @@ dependencies = [
  "node-primitives 2.0.0",
  "node-runtime 2.0.0",
  "parity-multiaddr 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_json 1.0.40 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -5089,7 +5110,7 @@ version = "2.0.0"
 dependencies = [
  "env_logger 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "substrate-primitives 2.0.0",
 ]
@@ -5102,7 +5123,7 @@ dependencies = [
  "hex-literal 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "num-traits 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "substrate-panic-handler 2.0.0",
  "substrate-primitives 2.0.0",
@@ -5138,7 +5159,7 @@ version = "2.0.0"
 dependencies = [
  "futures-preview 0.3.0-alpha.17 (registry+https://github.com/rust-lang/crates.io-index)",
  "hash-db 0.15.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-primitives 2.0.0",
  "substrate-client 2.0.0",
  "substrate-client-db 2.0.0",
@@ -5156,7 +5177,7 @@ dependencies = [
  "cfg-if 0.1.9 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "memory-db 0.15.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
  "sr-primitives 2.0.0",
@@ -5188,7 +5209,7 @@ dependencies = [
 name = "substrate-test-runtime-client"
 version = "2.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-primitives 2.0.0",
  "substrate-primitives 2.0.0",
  "substrate-test-client 2.0.0",
@@ -5204,7 +5225,7 @@ dependencies = [
  "env_logger 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures-preview 0.3.0-alpha.17 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-primitives 2.0.0",
@@ -5218,7 +5239,7 @@ version = "2.0.0"
 dependencies = [
  "derive_more 0.14.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-primitives 2.0.0",
  "substrate-client 2.0.0",
@@ -5237,7 +5258,7 @@ dependencies = [
  "hex-literal 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "keccak-hasher 0.15.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "memory-db 0.15.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-std 2.0.0",
  "substrate-primitives 2.0.0",
  "trie-bench 0.16.2 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -5638,7 +5659,7 @@ name = "transaction-factory"
 version = "0.0.1"
 dependencies = [
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-primitives 2.0.0",
  "substrate-cli 2.0.0",
  "substrate-client 2.0.0",
@@ -5656,7 +5677,7 @@ dependencies = [
  "hash-db 0.15.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "keccak-hasher 0.15.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "memory-db 0.15.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "trie-db 0.15.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "trie-root 0.15.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "trie-standardmap 0.15.2 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -5724,7 +5745,7 @@ name = "twox-hash"
 version = "1.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "rand 0.3.23 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -5823,6 +5844,16 @@ dependencies = [
  "percent-encoding 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "url"
+version = "2.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "idna 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "matches 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)",
+ "percent-encoding 2.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "utf8-ranges"
 version = "1.0.3"
@@ -5838,16 +5869,6 @@ name = "vec_map"
 version = "0.8.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
-[[package]]
-name = "vecarray"
-version = "0.1.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "parity-codec 4.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
- "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
- "typenum 1.10.0 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
 [[package]]
 name = "vergen"
 version = "3.0.4"
@@ -6135,7 +6156,7 @@ dependencies = [
 
 [[package]]
 name = "ws"
-version = "0.8.1"
+version = "0.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "byteorder 1.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -6147,7 +6168,7 @@ dependencies = [
  "rand 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "sha-1 0.8.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "slab 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "url 1.7.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "url 2.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -6240,7 +6261,6 @@ dependencies = [
 "checksum bindgen 0.47.3 (registry+https://github.com/rust-lang/crates.io-index)" = "df683a55b54b41d5ea8ebfaebb5aa7e6b84e3f3006a78f010dadc9ca88469260"
 "checksum bitflags 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "3d155346769a6855b86399e9bc3814ab343cd3d62c7e985113d46a0ec3c281fd"
 "checksum bitmask 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)" = "5da9b3d9f6f585199287a473f4f8dfab6566cf827d15c00c219f53c645687ead"
-"checksum bitvec 0.11.3 (registry+https://github.com/rust-lang/crates.io-index)" = "b67491e1cc6f37da6c4415cd743cb8d2e2c65388acc91ca3094a054cbf3cbd0c"
 "checksum bitvec 0.14.0 (registry+https://github.com/rust-lang/crates.io-index)" = "9633b74910e1870f50f5af189b08487195cdb83c0e27a71d6f64d5e09dd0538b"
 "checksum blake2 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)" = "91721a6330935673395a0607df4d49a9cb90ae12d259f1b3e0a3f6e1d486872e"
 "checksum blake2-rfc 0.2.18 (registry+https://github.com/rust-lang/crates.io-index)" = "5d6d530bdd2d52966a6d03b7a964add7ae1a288d25214066fd4b600f0f796400"
@@ -6365,7 +6385,9 @@ dependencies = [
 "checksum humantime 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "3ca7e5f2e110db35f93b837c81797f3714500b81d517bf20c431b16d3ca4f114"
 "checksum hyper 0.10.16 (registry+https://github.com/rust-lang/crates.io-index)" = "0a0652d9a2609a968c14be1a9ea00bf4b1d64e2e1f53a1b51b6fff3a6e829273"
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+"checksum hyper-tls 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)" = "3a800d6aa50af4b5850b2b0f659625ce9504df908e9733b635720483be26174f"
 "checksum idna 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "38f09e0f0b1fb55fdee1f17470ad800da77af5186a1a76c026b679358b7e844e"
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 "checksum impl-serde 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "5158079de9d4158e0ce1de3ae0bd7be03904efc40b3d7dd8b8c301cbf6b52b56"
 "checksum impl-serde 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "7d26be4b97d738552ea423f76c4f681012ff06c3fa36fa968656b3679f60b4a1"
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@@ -6443,7 +6465,7 @@ dependencies = [
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-"checksum multistream-select 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)" = "51a032ec01abdbe99a1165cd3e518bdd4bd7ca509a59ae9adf186d240399b90c"
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@@ -6466,10 +6488,9 @@ dependencies = [
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 "checksum parity-bytes 0.1.0 (git+https://github.com/paritytech/parity-common?rev=b0317f649ab2c665b7987b8475878fc4d2e1f81d)" = "<none>"
-"checksum parity-codec 4.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "2900f06356edf90de66a2922db622b36178dca71e85625eae58d0d9cc6cff2ac"
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-"checksum parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)" = "00fd14ff806ad82cea9a8f909bb116443d92efda7c9acd4502690af64741ad81"
+"checksum parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)" = "65582b5c02128a4b0fa60fb3e070216e9c84be3e4a8f1b74bc37e15a25e58daf"
 "checksum parity-scale-codec-derive 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)" = "a81f3cd93ed368a8e41c4e79538e99ca6e8f536096de23e3a0bc3e782093ce28"
 "checksum parity-send-wrapper 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "aa9777aa91b8ad9dd5aaa04a9b6bcb02c7f1deb952fca5a66034d5e63afc5c6f"
 "checksum parity-util-mem 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "e2005637ccf93dbb60c85081ccaaf3f945f573da48dcc79f27f9646caa3ec1dc"
@@ -6489,6 +6510,7 @@ dependencies = [
 "checksum pbkdf2 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "006c038a43a45995a9670da19e67600114740e8511d4333bf97a56e66a7542d9"
 "checksum peeking_take_while 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "19b17cddbe7ec3f8bc800887bab5e717348c95ea2ca0b1bf0837fb964dc67099"
 "checksum percent-encoding 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)" = "31010dd2e1ac33d5b46a5b413495239882813e0369f8ed8a5e266f173602f831"
+"checksum percent-encoding 2.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "d4fd5641d01c8f18a23da7b6fe29298ff4b55afcccdf78973b24cf3175fee32e"
 "checksum pin-utils 0.1.0-alpha.4 (registry+https://github.com/rust-lang/crates.io-index)" = "5894c618ce612a3fa23881b152b608bafb8c56cfc22f434a3ba3120b40f7b587"
 "checksum pkg-config 0.3.15 (registry+https://github.com/rust-lang/crates.io-index)" = "a7c1d2cfa5a714db3b5f24f0915e74fcdf91d09d496ba61329705dda7774d2af"
 "checksum ppv-lite86 0.2.5 (registry+https://github.com/rust-lang/crates.io-index)" = "e3cbf9f658cdb5000fcf6f362b8ea2ba154b9f146a61c7a20d647034c6b6561b"
@@ -6643,10 +6665,10 @@ dependencies = [
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 "checksum untrusted 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)" = "55cd1f4b4e96b46aeb8d4855db4a7a9bd96eeeb5c6a1ab54593328761642ce2f"
 "checksum url 1.7.2 (registry+https://github.com/rust-lang/crates.io-index)" = "dd4e7c0d531266369519a4aa4f399d748bd37043b00bde1e4ff1f60a120b355a"
+"checksum url 2.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "75b414f6c464c879d7f9babf951f23bc3743fb7313c081b2e6ca719067ea9d61"
 "checksum utf8-ranges 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)" = "9d50aa7650df78abf942826607c62468ce18d9019673d4a2ebe1865dbb96ffde"
 "checksum vcpkg 0.2.7 (registry+https://github.com/rust-lang/crates.io-index)" = "33dd455d0f96e90a75803cfeb7f948768c08d70a6de9a8d2362461935698bf95"
 "checksum vec_map 0.8.1 (registry+https://github.com/rust-lang/crates.io-index)" = "05c78687fb1a80548ae3250346c3db86a80a7cdd77bda190189f2d0a0987c81a"
-"checksum vecarray 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "d4d68a73b7d7d950c6558b6009e9fba229fb67562bda9fd02198f614f4ecf83f"
 "checksum vergen 3.0.4 (registry+https://github.com/rust-lang/crates.io-index)" = "6aba5e34f93dc7051dfad05b98a18e9156f27e7b431fe1d2398cb6061c0a1dba"
 "checksum version_check 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "914b1a6776c4c929a602fafd8bc742e06365d4bcbe48c30f9cca5824f70dc9dd"
 "checksum void 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)" = "6a02e4885ed3bc0f2de90ea6dd45ebcbb66dacffe03547fadbb0eeae2770887d"
@@ -6677,7 +6699,7 @@ dependencies = [
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 "checksum winapi-x86_64-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"
 "checksum wincolor 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)" = "561ed901ae465d6185fa7864d63fbd5720d0ef718366c9a4dc83cf6170d7e9ba"
-"checksum ws 0.8.1 (registry+https://github.com/rust-lang/crates.io-index)" = "ec91ea61b83ce033c43c06c52ddc7532f465c0153281610d44c58b74083aee1a"
+"checksum ws 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)" = "8a6f5bb86663ff4d1639408410f50bf6050367a8525d644d49a6894cd618a631"
 "checksum ws2_32-sys 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "d59cefebd0c892fa2dd6de581e937301d8552cb44489cdff035c6187cb63fa5e"
 "checksum x25519-dalek 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)" = "7ee1585dc1484373cbc1cee7aafda26634665cf449436fd6e24bfd1fad230538"
 "checksum xdg 2.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "d089681aa106a86fade1b0128fb5daf07d5867a509ab036d99988dec80429a57"
diff --git a/README.adoc b/README.adoc
index aaab6df3cc2f2..91c473c347e05 100644
--- a/README.adoc
+++ b/README.adoc
@@ -133,7 +133,7 @@ First let's get a template chainspec that you can edit. We'll use the "staging"
 substrate build-spec --chain=staging > ~/chainspec.json
 ----
 
-Now, edit `~/chainspec.json` in your editor. There are a lot of individual fields for each module, and one very large one which contains the Webassembly code blob for this chain. The easiest field to edit is the block `period`. Change it to 10 (seconds):
+Now, edit `~/chainspec.json` in your editor. There are a lot of individual fields for each module, and one very large one which contains the WebAssembly code blob for this chain. The easiest field to edit is the block `period`. Change it to 10 (seconds):
 
 [source, json]
 ----
@@ -160,7 +160,7 @@ It won't do much until you start producing blocks though, so to do that you'll n
 
 [source, shell]
 ----
-substrate --chain ~/mychain.json --validator --key ...
+substrate --chain ~/mychain.json --validator
 ----
 
 You can distribute `mychain.json` so that everyone can synchronize and (depending on your authorities list) validate on your chain.
@@ -281,9 +281,9 @@ cargo run \-- --dev
 
 Detailed logs may be shown by running the node with the following environment variables set: `RUST_LOG=debug RUST_BACKTRACE=1 cargo run \-- --dev`.
 
-If you want to see the multi-node consensus algorithm in action locally, then you can create a local testnet with two validator nodes for Alice and Bob, who are the initial authorities of the genesis chain specification that have been endowed with a testnet DOTs. We'll give each node a name and expose them so they are listed on link:https://telemetry.polkadot.io/#/Local%20Testnet[Telemetry] . You'll need two terminals windows open.
+If you want to see the multi-node consensus algorithm in action locally, then you can create a local testnet with two validator nodes for Alice and Bob, who are the initial authorities of the genesis chain specification that have been endowed with a testnet DOTs. We'll give each node a name and expose them so they are listed on link:https://telemetry.polkadot.io/#/Local%20Testnet[Telemetry]. You'll need two terminal windows open.
 
-We'll start Alice's substrate node first on default TCP port 30333 with her chain database stored locally at `/tmp/alice`. The Bootnode ID of her node is `QmRpheLN4JWdAnY7HGJfWFNbfkQCb6tFf4vvA6hgjMZKrR`, which is generated from the `--node-key` value that we specify below:
+We'll start Alice's Substrate node first on default TCP port 30333 with her chain database stored locally at `/tmp/alice`. The Bootnode ID of her node is `QmRpheLN4JWdAnY7HGJfWFNbfkQCb6tFf4vvA6hgjMZKrR`, which is generated from the `--node-key` value that we specify below:
 
 [source, shell]
 cargo run --release \-- \
@@ -294,7 +294,7 @@ cargo run --release \-- \
   --telemetry-url ws://telemetry.polkadot.io:1024 \
   --validator
 
-In the second terminal, we'll run the following to start Bob's substrate node on a different TCP port of 30334, and with his chain database stored locally at `/tmp/bob`. We'll specify a value for the `--bootnodes` option that will connect his node to Alice's Bootnode ID on TCP port 30333:
+In the second terminal, we'll run the following to start Bob's Substrate node on a different TCP port of 30334, and with his chain database stored locally at `/tmp/bob`. We'll specify a value for the `--bootnodes` option that will connect his node to Alice's Bootnode ID on TCP port 30333:
 
 [source, shell]
 cargo run --release \-- \
@@ -378,6 +378,38 @@ git checkout -b v1.0 origin/v1.0
 
 You can then follow the same steps for building and running as described above in <<flaming-fir>>.
 
+== Key management
+
+Keys in Substrate are stored in the keystore in the file system. To store keys into this keystore,
+you need to use one of the two provided RPC calls. If your keys are encrypted or should be encrypted
+by the keystore, you need to provide the key using one of the cli arguments `--password`,
+`--password-interactive` or `--password-filename`.
+
+=== Recommended RPC call
+
+For most users who want to run a validator node, the `author_rotateKeys` RPC call is sufficient.
+The RPC call will generate `N` Session keys for you and return their public keys. `N` is the number
+of session keys configured in the runtime. The output of the RPC call can be used as input for the
+`session::set_keys` transaction.
+
+```
+curl -H 'Content-Type: application/json' --data '{ "jsonrpc":"2.0", "method":"author_rotateKeys", "id":1 }' localhost:9933
+```
+
+=== Advanced RPC call
+
+If the Session keys need to match a fixed seed, they can be set individually key by key. The RPC call
+expects the key seed and the key type. The key types supported by default in Substrate are listed
+https://github.com/paritytech/substrate/blob/master/core/primitives/src/crypto.rs#L767[here], but the
+user can declare any key type.
+
+```
+curl -H 'Content-Type: application/json' --data '{ "jsonrpc":"2.0", "method":"author_insertKey", "params":["KEY_TYPE", "SEED"],"id":1 }' localhost:9933
+```
+
+`KEY_TYPE` - needs to be replaced with the 4-character key type identifier.
+`SEED` - is the seed of the key.
+
 == Documentation
 
 === Viewing documentation for Substrate packages
diff --git a/core/application-crypto/src/traits.rs b/core/application-crypto/src/traits.rs
index d7f1eafe35407..323c9c3e54c55 100644
--- a/core/application-crypto/src/traits.rs
+++ b/core/application-crypto/src/traits.rs
@@ -17,6 +17,7 @@
 use primitives::crypto::{KeyTypeId, CryptoType, IsWrappedBy, Public};
 #[cfg(feature = "std")]
 use primitives::crypto::Pair;
+use codec::Codec;
 
 /// An application-specific key.
 pub trait AppKey: 'static + Send + Sync + Sized + CryptoType + Clone {
@@ -72,7 +73,7 @@ pub trait AppSignature: AppKey + Eq + PartialEq + MaybeDebugHash {
 /// A runtime interface for a public key.
 pub trait RuntimePublic: Sized {
 	/// The signature that will be generated when signing with the corresponding private key.
-	type Signature;
+	type Signature: Codec + MaybeDebugHash + Eq + PartialEq + Clone;
 
 	/// Returns all public keys for the given key type in the keystore.
 	fn all(key_type: KeyTypeId) -> crate::Vec<Self>;
@@ -97,7 +98,7 @@ pub trait RuntimePublic: Sized {
 /// A runtime interface for an application's public key.
 pub trait RuntimeAppPublic: Sized {
 	/// The signature that will be generated when signing with the corresponding private key.
-	type Signature;
+	type Signature: Codec + MaybeDebugHash + Eq + PartialEq + Clone;
 
 	/// Returns all public keys for this application in the keystore.
 	fn all() -> crate::Vec<Self>;
diff --git a/core/cli/src/informant.rs b/core/cli/src/informant.rs
index b5a2f03d79546..52a5f67c26d59 100644
--- a/core/cli/src/informant.rs
+++ b/core/cli/src/informant.rs
@@ -21,22 +21,12 @@ use futures::{Future, Stream};
 use futures03::{StreamExt as _, TryStreamExt as _};
 use log::{info, warn};
 use sr_primitives::{generic::BlockId, traits::Header};
-use service::{Service, Components};
-use tokio::runtime::TaskExecutor;
+use service::AbstractService;
 
 mod display;
 
-/// Spawn informant on the event loop
-#[deprecated(note = "Please use informant::build instead, and then create the task manually")]
-pub fn start<C>(service: &Service<C>, exit: ::exit_future::Exit, handle: TaskExecutor) where
-	C: Components,
-{
-	handle.spawn(exit.until(build(service)).map(|_| ()));
-}
-
 /// Creates an informant in the form of a `Future` that must be polled regularly.
-pub fn build<C>(service: &Service<C>) -> impl Future<Item = (), Error = ()>
-where C: Components {
+pub fn build(service: &impl AbstractService) -> impl Future<Item = (), Error = ()> {
 	let client = service.client();
 
 	let mut display = display::InformantDisplay::new();
diff --git a/core/cli/src/lib.rs b/core/cli/src/lib.rs
index ef5290413166d..6e9955ca1a48b 100644
--- a/core/cli/src/lib.rs
+++ b/core/cli/src/lib.rs
@@ -29,8 +29,8 @@ pub mod informant;
 use client::ExecutionStrategies;
 use service::{
 	config::Configuration,
-	ServiceFactory, FactoryFullConfiguration, RuntimeGenesis,
-	FactoryGenesis, PruningMode, ChainSpec,
+	ServiceBuilderExport, ServiceBuilderImport, ServiceBuilderRevert,
+	RuntimeGenesis, PruningMode, ChainSpec,
 };
 use network::{
 	self, multiaddr::Protocol,
@@ -317,13 +317,17 @@ pub struct ParseAndPrepareExport<'a> {
 
 impl<'a> ParseAndPrepareExport<'a> {
 	/// Runs the command and exports from the chain.
-	pub fn run<F, S, E>(
+	pub fn run_with_builder<C, G, F, B, S, E>(
 		self,
+		builder: F,
 		spec_factory: S,
 		exit: E,
 	) -> error::Result<()>
-	where S: FnOnce(&str) -> Result<Option<ChainSpec<FactoryGenesis<F>>>, String>,
-		F: ServiceFactory,
+	where S: FnOnce(&str) -> Result<Option<ChainSpec<G>>, String>,
+		F: FnOnce(Configuration<C, G>) -> Result<B, error::Error>,
+		B: ServiceBuilderExport,
+		C: Default,
+		G: RuntimeGenesis,
 		E: IntoExit
 	{
 		let config = create_config_with_db_path(spec_factory, &self.params.shared_params, self.version)?;
@@ -338,9 +342,8 @@ impl<'a> ParseAndPrepareExport<'a> {
 			None => Box::new(stdout()),
 		};
 
-		service::chain_ops::export_blocks::<F, _, _>(
-			config, exit.into_exit(), file, from.into(), to.map(Into::into), json
-		).map_err(Into::into)
+		builder(config)?.export_blocks(exit.into_exit(), file, from.into(), to.map(Into::into), json)?;
+		Ok(())
 	}
 }
 
@@ -352,13 +355,17 @@ pub struct ParseAndPrepareImport<'a> {
 
 impl<'a> ParseAndPrepareImport<'a> {
 	/// Runs the command and imports to the chain.
-	pub fn run<F, S, E>(
+	pub fn run_with_builder<C, G, F, B, S, E>(
 		self,
+		builder: F,
 		spec_factory: S,
 		exit: E,
 	) -> error::Result<()>
-	where S: FnOnce(&str) -> Result<Option<ChainSpec<FactoryGenesis<F>>>, String>,
-		F: ServiceFactory,
+	where S: FnOnce(&str) -> Result<Option<ChainSpec<G>>, String>,
+		F: FnOnce(Configuration<C, G>) -> Result<B, error::Error>,
+		B: ServiceBuilderImport,
+		C: Default,
+		G: RuntimeGenesis,
 		E: IntoExit
 	{
 		let mut config = create_config_with_db_path(spec_factory, &self.params.shared_params, self.version)?;
@@ -377,7 +384,7 @@ impl<'a> ParseAndPrepareImport<'a> {
 			},
 		};
 
-		let fut = service::chain_ops::import_blocks::<F, _, _>(config, exit.into_exit(), file)?;
+		let fut = builder(config)?.import_blocks(exit.into_exit(), file)?;
 		tokio::run(fut);
 		Ok(())
 	}
@@ -440,67 +447,23 @@ pub struct ParseAndPrepareRevert<'a> {
 
 impl<'a> ParseAndPrepareRevert<'a> {
 	/// Runs the command and reverts the chain.
-	pub fn run<F, S>(
+	pub fn run_with_builder<C, G, F, B, S>(
 		self,
+		builder: F,
 		spec_factory: S
 	) -> error::Result<()>
-	where S: FnOnce(&str) -> Result<Option<ChainSpec<FactoryGenesis<F>>>, String>,
-		F: ServiceFactory {
+	where S: FnOnce(&str) -> Result<Option<ChainSpec<G>>, String>,
+		F: FnOnce(Configuration<C, G>) -> Result<B, error::Error>,
+		B: ServiceBuilderRevert,
+		C: Default,
+		G: RuntimeGenesis {
 		let config = create_config_with_db_path(spec_factory, &self.params.shared_params, self.version)?;
 		let blocks = self.params.num;
-		Ok(service::chain_ops::revert_chain::<F>(config, blocks.into())?)
+		builder(config)?.revert_chain(blocks.into())?;
+		Ok(())
 	}
 }
 
-/// Parse command line interface arguments and executes the desired command.
-///
-/// # Return value
-///
-/// A result that indicates if any error occurred.
-/// If no error occurred and a custom subcommand was found, the subcommand is returned.
-/// The user needs to handle this subcommand on its own.
-///
-/// # Remarks
-///
-/// `CC` is a custom subcommand. This needs to be an `enum`! If no custom subcommand is required,
-/// `NoCustom` can be used as type here.
-/// `RP` are custom parameters for the run command. This needs to be a `struct`! The custom
-/// parameters are visible to the user as if they were normal run command parameters. If no custom
-/// parameters are required, `NoCustom` can be used as type here.
-#[deprecated(
-	note = "Use parse_and_prepare instead; see the source code of parse_and_execute for how to transition"
-)]
-pub fn parse_and_execute<'a, F, CC, RP, S, RS, E, I, T>(
-	spec_factory: S,
-	version: &VersionInfo,
-	impl_name: &'static str,
-	args: I,
-	exit: E,
-	run_service: RS,
-) -> error::Result<Option<CC>>
-where
-	F: ServiceFactory,
-	S: FnOnce(&str) -> Result<Option<ChainSpec<FactoryGenesis<F>>>, String>,
-	CC: StructOpt + Clone + GetLogFilter,
-	RP: StructOpt + Clone + AugmentClap,
-	E: IntoExit,
-	RS: FnOnce(E, RunCmd, RP, FactoryFullConfiguration<F>) -> Result<(), String>,
-	I: IntoIterator<Item = T>,
-	T: Into<std::ffi::OsString> + Clone,
-{
-	match parse_and_prepare::<CC, RP, _>(version, impl_name, args) {
-		ParseAndPrepare::Run(cmd) => cmd.run(spec_factory, exit, run_service),
-		ParseAndPrepare::BuildSpec(cmd) => cmd.run(spec_factory),
-		ParseAndPrepare::ExportBlocks(cmd) => cmd.run::<F, _, _>(spec_factory, exit),
-		ParseAndPrepare::ImportBlocks(cmd) => cmd.run::<F, _, _>(spec_factory, exit),
-		ParseAndPrepare::PurgeChain(cmd) => cmd.run(spec_factory),
-		ParseAndPrepare::RevertChain(cmd) => cmd.run::<F, _>(spec_factory),
-		ParseAndPrepare::CustomCommand(cmd) => return Ok(Some(cmd))
-	}?;
-
-	Ok(None)
-}
-
 /// Create a `NodeKeyConfig` from the given `NodeKeyParams` in the context
 /// of an optional network config storage directory.
 fn node_key_config<P>(params: NodeKeyParams, net_config_dir: &Option<P>)
diff --git a/core/cli/src/params.rs b/core/cli/src/params.rs
index 72adc552b9ecd..0f58527287eb7 100644
--- a/core/cli/src/params.rs
+++ b/core/cli/src/params.rs
@@ -441,7 +441,11 @@ lazy_static::lazy_static! {
 	/// The Cli values for all test accounts.
 	static ref TEST_ACCOUNTS_CLI_VALUES: Vec<KeyringTestAccountCliValues> = {
 		keyring::Sr25519Keyring::iter().map(|a| {
-			let help = format!("Shortcut for `--key //{} --name {}`.", a, a);
+			let help = format!(
+				"Shortcut for `--name {} --validator` with session keys for `{}` added to keystore.",
+				a,
+				a,
+			);
 			let conflicts_with = keyring::Sr25519Keyring::iter()
 				.filter(|b| a != *b)
 				.map(|b| b.to_string().to_lowercase())
diff --git a/core/client/db/src/cache/mod.rs b/core/client/db/src/cache/mod.rs
index 68245a54eeeac..f53eb54ca04f6 100644
--- a/core/client/db/src/cache/mod.rs
+++ b/core/client/db/src/cache/mod.rs
@@ -299,8 +299,8 @@ impl<Block: BlockT> BlockchainCache<Block> for DbCacheSync<Block> {
 		key: &CacheKeyId,
 		at: &BlockId<Block>,
 	) -> Option<((NumberFor<Block>, Block::Hash), Option<(NumberFor<Block>, Block::Hash)>, Vec<u8>)> {
-		let cache = self.0.read();
-		let storage = cache.cache_at.get(key)?.storage();
+		let mut cache = self.0.write();
+		let storage = cache.get_cache(*key).storage();
 		let db = storage.db();
 		let columns = storage.columns();
 		let at = match *at {
diff --git a/core/client/db/src/light.rs b/core/client/db/src/light.rs
index 2ee2c2ec54531..86408a155d197 100644
--- a/core/client/db/src/light.rs
+++ b/core/client/db/src/light.rs
@@ -1030,26 +1030,37 @@ pub(crate) mod tests {
 
 	#[test]
 	fn cache_can_be_initialized_after_genesis_inserted() {
-		let db = LightStorage::<Block>::new_test();
+		let (genesis_hash, storage) = {
+			let db = LightStorage::<Block>::new_test();
+
+			// before cache is initialized => None
+			assert_eq!(db.cache().get_at(b"test", &BlockId::Number(0)), None);
+
+			// insert genesis block (no value for cache is provided)
+			let mut genesis_hash = None;
+			insert_block(&db, HashMap::new(), || {
+				let header = default_header(&Default::default(), 0);
+				genesis_hash = Some(header.hash());
+				header
+			});
 
-		// before cache is initialized => None
-		assert_eq!(db.cache().get_at(b"test", &BlockId::Number(0)), None);
+			// after genesis is inserted => None
+			assert_eq!(db.cache().get_at(b"test", &BlockId::Number(0)), None);
 
-		// insert genesis block (no value for cache is provided)
-		let mut genesis_hash = None;
-		insert_block(&db, HashMap::new(), || {
-			let header = default_header(&Default::default(), 0);
-			genesis_hash = Some(header.hash());
-			header
-		});
+			// initialize cache
+			db.cache().initialize(b"test", vec![42]).unwrap();
 
-		// after genesis is inserted => None
-		assert_eq!(db.cache().get_at(b"test", &BlockId::Number(0)), None);
+			// after genesis is inserted + cache is initialized => Some
+			assert_eq!(
+				db.cache().get_at(b"test", &BlockId::Number(0)),
+				Some(((0, genesis_hash.unwrap()), None, vec![42])),
+			);
 
-		// initialize cache
-		db.cache().initialize(b"test", vec![42]).unwrap();
+			(genesis_hash, db.db)
+		};
 
-		// after genesis is inserted + cache is initialized => Some
+		// restart && check that after restart value is read from the cache
+		let db = LightStorage::<Block>::from_kvdb(storage as Arc<_>).expect("failed to create test-db");
 		assert_eq!(
 			db.cache().get_at(b"test", &BlockId::Number(0)),
 			Some(((0, genesis_hash.unwrap()), None, vec![42])),
diff --git a/core/client/src/client.rs b/core/client/src/client.rs
index c6234dc8d1cca..a57584575cc23 100644
--- a/core/client/src/client.rs
+++ b/core/client/src/client.rs
@@ -27,8 +27,9 @@ use codec::{Encode, Decode};
 use hash_db::{Hasher, Prefix};
 use primitives::{
 	Blake2Hasher, H256, ChangesTrieConfiguration, convert_hash,
-	NeverNativeValue, ExecutionContext,
-	storage::{StorageKey, StorageData, well_known_keys}, NativeOrEncoded
+	NeverNativeValue, ExecutionContext, NativeOrEncoded,
+	storage::{StorageKey, StorageData, well_known_keys},
+	offchain,
 };
 use substrate_telemetry::{telemetry, SUBSTRATE_INFO};
 use sr_primitives::{
@@ -1471,8 +1472,6 @@ impl<B, E, Block, RA> CallRuntimeAt<Block> for Client<B, E, Block, RA> where
 		context: ExecutionContext,
 		recorder: &Option<Rc<RefCell<ProofRecorder<Block>>>>,
 	) -> error::Result<NativeOrEncoded<R>> {
-		let enable_keystore = context.enable_keystore();
-
 		let manager = match context {
 			ExecutionContext::BlockConstruction =>
 				self.execution_strategies.block_construction.get_manager(),
@@ -1480,16 +1479,17 @@ impl<B, E, Block, RA> CallRuntimeAt<Block> for Client<B, E, Block, RA> where
 				self.execution_strategies.syncing.get_manager(),
 			ExecutionContext::Importing =>
 				self.execution_strategies.importing.get_manager(),
-			ExecutionContext::OffchainWorker(_) =>
+			ExecutionContext::OffchainCall(Some((_, capabilities))) if capabilities.has_all() =>
 				self.execution_strategies.offchain_worker.get_manager(),
-			ExecutionContext::Other =>
+			ExecutionContext::OffchainCall(_) =>
 				self.execution_strategies.other.get_manager(),
 		};
 
+		let capabilities = context.capabilities();
 		let mut offchain_extensions = match context {
-			ExecutionContext::OffchainWorker(ext) => Some(ext),
+			ExecutionContext::OffchainCall(ext) => ext.map(|x| x.0),
 			_ => None,
-		};
+		}.map(|ext| offchain::LimitedExternalities::new(capabilities, ext));
 
 		self.executor.contextual_call::<_, _, fn(_,_) -> _,_,_>(
 			|| core_api.initialize_block(at, &self.prepare_environment_block(at)?),
@@ -1502,7 +1502,7 @@ impl<B, E, Block, RA> CallRuntimeAt<Block> for Client<B, E, Block, RA> where
 			native_call,
 			offchain_extensions.as_mut(),
 			recorder,
-			enable_keystore,
+			capabilities.has(offchain::Capability::Keystore),
 		)
 	}
 
diff --git a/core/client/src/genesis.rs b/core/client/src/genesis.rs
index 3ac93f4f577b6..4791a34d17427 100644
--- a/core/client/src/genesis.rs
+++ b/core/client/src/genesis.rs
@@ -54,8 +54,7 @@ mod tests {
 	native_executor_instance!(
 		Executor,
 		test_client::runtime::api::dispatch,
-		test_client::runtime::native_version,
-		test_client::runtime::WASM_BINARY
+		test_client::runtime::native_version
 	);
 
 	fn executor() -> executor::NativeExecutor<Executor> {
@@ -153,6 +152,7 @@ mod tests {
 			vec![AccountKeyring::One.into(), AccountKeyring::Two.into()],
 			1000,
 			None,
+			vec![],
 		).genesis_map();
 		let genesis_hash = insert_genesis_block(&mut storage);
 
@@ -181,6 +181,7 @@ mod tests {
 			vec![AccountKeyring::One.into(), AccountKeyring::Two.into()],
 			1000,
 			None,
+			vec![],
 		).genesis_map();
 		let genesis_hash = insert_genesis_block(&mut storage);
 
@@ -209,6 +210,7 @@ mod tests {
 			vec![AccountKeyring::One.into(), AccountKeyring::Two.into()],
 			68,
 			None,
+			vec![],
 		).genesis_map();
 		let genesis_hash = insert_genesis_block(&mut storage);
 
diff --git a/core/client/src/light/call_executor.rs b/core/client/src/light/call_executor.rs
index 2367aaf806510..746f36069d69e 100644
--- a/core/client/src/light/call_executor.rs
+++ b/core/client/src/light/call_executor.rs
@@ -471,7 +471,7 @@ pub fn check_execution_proof<Header, E, H>(
 		Default::default(),
 		Default::default(),
 		request.header.hash(),
-		request.header.digest().clone(),
+		Default::default(),
 	);
 	execution_proof_check_on_trie_backend::<H, _>(
 		&trie_backend,
@@ -498,7 +498,7 @@ pub fn check_execution_proof<Header, E, H>(
 #[cfg(test)]
 mod tests {
 	use consensus::BlockOrigin;
-	use test_client::{self, runtime::Header, ClientExt, TestClient};
+	use test_client::{self, runtime::{Header, Digest}, ClientExt, TestClient};
 	use executor::NativeExecutor;
 	use crate::backend::{Backend, NewBlockState};
 	use crate::in_mem::Backend as InMemBackend;
@@ -509,8 +509,7 @@ mod tests {
 	fn execution_proof_is_generated_and_checked() {
 		fn execute(remote_client: &TestClient, at: u64, method: &'static str) -> (Vec<u8>, Vec<u8>) {
 			let remote_block_id = BlockId::Number(at);
-			let remote_root = remote_client.state_at(&remote_block_id)
-				.unwrap().storage_root(::std::iter::empty()).0;
+			let remote_header = remote_client.header(&remote_block_id).unwrap().unwrap();
 
 			// 'fetch' execution proof from remote node
 			let (remote_result, remote_execution_proof) = remote_client.execution_proof(
@@ -523,13 +522,7 @@ mod tests {
 			let local_executor = NativeExecutor::<test_client::LocalExecutor>::new(None);
 			let local_result = check_execution_proof(&local_executor, &RemoteCallRequest {
 				block: test_client::runtime::Hash::default(),
-				header: test_client::runtime::Header {
-					state_root: remote_root.into(),
-					parent_hash: Default::default(),
-					number: at,
-					extrinsics_root: Default::default(),
-					digest: Default::default(),
-				},
+				header: remote_header,
 				method: method.into(),
 				call_data: vec![],
 				retry_count: None,
@@ -540,10 +533,12 @@ mod tests {
 
 		// prepare remote client
 		let remote_client = test_client::new();
-		for _ in 1..3 {
+		for i in 1u32..3u32 {
+			let mut digest = Digest::default();
+			digest.push(sr_primitives::generic::DigestItem::Other::<H256>(i.to_le_bytes().to_vec()));
 			remote_client.import_justified(
 				BlockOrigin::Own,
-				remote_client.new_block(Default::default()).unwrap().bake().unwrap(),
+				remote_client.new_block(digest).unwrap().bake().unwrap(),
 				Default::default(),
 			).unwrap();
 		}
diff --git a/core/consensus/aura/primitives/src/lib.rs b/core/consensus/aura/primitives/src/lib.rs
index 84671e5ae6864..e4620fcdbfdd4 100644
--- a/core/consensus/aura/primitives/src/lib.rs
+++ b/core/consensus/aura/primitives/src/lib.rs
@@ -23,38 +23,38 @@ use substrate_client::decl_runtime_apis;
 use rstd::vec::Vec;
 use sr_primitives::ConsensusEngineId;
 
-mod app_sr25519 {
-	use app_crypto::{app_crypto, key_types::AURA, sr25519};
-	app_crypto!(sr25519, AURA);
-}
-
 pub mod sr25519 {
+	mod app_sr25519 {
+		use app_crypto::{app_crypto, key_types::AURA, sr25519};
+		app_crypto!(sr25519, AURA);
+	}
+
 	/// An Aura authority keypair using S/R 25519 as its crypto.
 	#[cfg(feature = "std")]
-	pub type AuthorityPair = super::app_sr25519::Pair;
+	pub type AuthorityPair = app_sr25519::Pair;
 
 	/// An Aura authority signature using S/R 25519 as its crypto.
-	pub type AuthoritySignature = super::app_sr25519::Signature;
+	pub type AuthoritySignature = app_sr25519::Signature;
 
 	/// An Aura authority identifier using S/R 25519 as its crypto.
-	pub type AuthorityId = super::app_sr25519::Public;
-}
-
-mod app_ed25519 {
-	use app_crypto::{app_crypto, key_types::AURA, ed25519};
-	app_crypto!(ed25519, AURA);
+	pub type AuthorityId = app_sr25519::Public;
 }
 
 pub mod ed25519 {
+	mod app_ed25519 {
+		use app_crypto::{app_crypto, key_types::AURA, ed25519};
+		app_crypto!(ed25519, AURA);
+	}
+
 	/// An Aura authority keypair using Ed25519 as its crypto.
 	#[cfg(feature = "std")]
-	pub type AuthorityPair = super::app_ed25519::Pair;
+	pub type AuthorityPair = app_ed25519::Pair;
 
 	/// An Aura authority signature using Ed25519 as its crypto.
-	pub type AuthoritySignature = super::app_ed25519::Signature;
+	pub type AuthoritySignature = app_ed25519::Signature;
 
 	/// An Aura authority identifier using Ed25519 as its crypto.
-	pub type AuthorityId = super::app_ed25519::Public;
+	pub type AuthorityId = app_ed25519::Public;
 }
 
 /// The `ConsensusEngineId` of AuRa.
diff --git a/core/executor/src/native_executor.rs b/core/executor/src/native_executor.rs
index 937e0033539f0..1ebf7f31464a7 100644
--- a/core/executor/src/native_executor.rs
+++ b/core/executor/src/native_executor.rs
@@ -49,9 +49,6 @@ pub fn with_native_environment<F, U>(ext: &mut dyn Externalities<Blake2Hasher>,
 
 /// Delegate for dispatching a CodeExecutor call to native code.
 pub trait NativeExecutionDispatch: Send + Sync {
-	/// Get the wasm code that the native dispatch will be equivalent to.
-	fn native_equivalent() -> &'static [u8];
-
 	/// Dispatch a method and input data to be executed natively.
 	fn dispatch(ext: &mut dyn Externalities<Blake2Hasher>, method: &str, data: &[u8]) -> Result<Vec<u8>>;
 
@@ -211,19 +208,13 @@ impl<D: NativeExecutionDispatch> CodeExecutor<Blake2Hasher> for NativeExecutor<D
 /// Implements a `NativeExecutionDispatch` for provided parameters.
 #[macro_export]
 macro_rules! native_executor_instance {
-	( $pub:vis $name:ident, $dispatcher:path, $version:path, $code:expr) => {
+	( $pub:vis $name:ident, $dispatcher:path, $version:path $(,)?) => {
 		/// A unit struct which implements `NativeExecutionDispatch` feeding in the hard-coded runtime.
 		$pub struct $name;
-		$crate::native_executor_instance!(IMPL $name, $dispatcher, $version, $code);
+		$crate::native_executor_instance!(IMPL $name, $dispatcher, $version);
 	};
-	(IMPL $name:ident, $dispatcher:path, $version:path, $code:expr) => {
+	(IMPL $name:ident, $dispatcher:path, $version:path) => {
 		impl $crate::NativeExecutionDispatch for $name {
-			fn native_equivalent() -> &'static [u8] {
-				// WARNING!!! This assumes that the runtime was built *before* the main project. Until we
-				// get a proper build script, this must be strictly adhered to or things will go wrong.
-				$code
-			}
-
 			fn dispatch(
 				ext: &mut $crate::Externalities<$crate::Blake2Hasher>,
 				method: &str,
diff --git a/core/finality-grandpa/Cargo.toml b/core/finality-grandpa/Cargo.toml
index 22237c5a0b5a0..393ee45db5776 100644
--- a/core/finality-grandpa/Cargo.toml
+++ b/core/finality-grandpa/Cargo.toml
@@ -23,7 +23,6 @@ serde_json = "1.0"
 client = { package = "substrate-client", path = "../client" }
 inherents = { package = "substrate-inherents", path = "../../core/inherents" }
 network = { package = "substrate-network", path = "../network" }
-service = { package = "substrate-service", path = "../service", optional = true }
 srml-finality-tracker = { path = "../../srml/finality-tracker" }
 fg_primitives = { package = "substrate-finality-grandpa-primitives", path = "primitives" }
 grandpa = { package = "finality-grandpa", version = "0.9.0", features = ["derive-codec"] }
@@ -37,7 +36,3 @@ babe_primitives = { package = "substrate-consensus-babe-primitives", path = "../
 env_logger = "0.6"
 tokio = "0.1.17"
 tempfile = "3.1"
-
-[features]
-default = ["service-integration"]
-service-integration = ["service"]
diff --git a/core/finality-grandpa/primitives/src/lib.rs b/core/finality-grandpa/primitives/src/lib.rs
index b92444e26295c..1f103a548d1a6 100644
--- a/core/finality-grandpa/primitives/src/lib.rs
+++ b/core/finality-grandpa/primitives/src/lib.rs
@@ -52,6 +52,12 @@ pub type AuthorityWeight = u64;
 /// The index of an authority.
 pub type AuthorityIndex = u64;
 
+/// The identifier of a GRANDPA set.
+pub type SetId = u64;
+
+/// The round indicator.
+pub type RoundNumber = u64;
+
 /// A scheduled change of authority set.
 #[cfg_attr(feature = "std", derive(Debug, Serialize))]
 #[derive(Clone, Eq, PartialEq, Encode, Decode)]
diff --git a/core/finality-grandpa/src/aux_schema.rs b/core/finality-grandpa/src/aux_schema.rs
index 78c1741d51903..599604c1d32bf 100644
--- a/core/finality-grandpa/src/aux_schema.rs
+++ b/core/finality-grandpa/src/aux_schema.rs
@@ -26,7 +26,7 @@ use grandpa::round::State as RoundState;
 use sr_primitives::traits::{Block as BlockT, NumberFor};
 use log::{info, warn};
 use substrate_telemetry::{telemetry, CONSENSUS_INFO};
-use fg_primitives::AuthorityId;
+use fg_primitives::{AuthorityId, AuthorityWeight, SetId, RoundNumber};
 
 use crate::authorities::{AuthoritySet, SharedAuthoritySet, PendingChange, DelayKind};
 use crate::consensus_changes::{SharedConsensusChanges, ConsensusChanges};
@@ -47,16 +47,16 @@ const CURRENT_VERSION: u32 = 2;
 #[cfg_attr(test, derive(PartialEq))]
 pub enum V1VoterSetState<H, N> {
 	/// The voter set state, currently paused.
-	Paused(u64, RoundState<H, N>),
+	Paused(RoundNumber, RoundState<H, N>),
 	/// The voter set state, currently live.
-	Live(u64, RoundState<H, N>),
+	Live(RoundNumber, RoundState<H, N>),
 }
 
-type V0VoterSetState<H, N> = (u64, RoundState<H, N>);
+type V0VoterSetState<H, N> = (RoundNumber, RoundState<H, N>);
 
 #[derive(Debug, Clone, Encode, Decode, PartialEq)]
 struct V0PendingChange<H, N> {
-	next_authorities: Vec<(AuthorityId, u64)>,
+	next_authorities: Vec<(AuthorityId, AuthorityWeight)>,
 	delay: N,
 	canon_height: N,
 	canon_hash: H,
@@ -64,8 +64,8 @@ struct V0PendingChange<H, N> {
 
 #[derive(Debug, Clone, Encode, Decode, PartialEq)]
 struct V0AuthoritySet<H, N> {
-	current_authorities: Vec<(AuthorityId, u64)>,
-	set_id: u64,
+	current_authorities: Vec<(AuthorityId, AuthorityWeight)>,
+	set_id: SetId,
 	pending_changes: Vec<V0PendingChange<H, N>>,
 }
 
@@ -267,7 +267,7 @@ pub(crate) fn load_persistent<Block: BlockT, B, G>(
 	-> ClientResult<PersistentData<Block>>
 	where
 		B: AuxStore,
-		G: FnOnce() -> ClientResult<Vec<(AuthorityId, u64)>>,
+		G: FnOnce() -> ClientResult<Vec<(AuthorityId, AuthorityWeight)>>,
 {
 	let version: Option<u32> = load_decode(backend, VERSION_KEY)?;
 	let consensus_changes = load_decode(backend, CONSENSUS_CHANGES_KEY)?
@@ -448,7 +448,7 @@ mod test {
 
 		let authorities = vec![(AuthorityId::default(), 100)];
 		let set_id = 3;
-		let round_number: u64 = 42;
+		let round_number: RoundNumber = 42;
 		let round_state = RoundState::<H256, u64> {
 			prevote_ghost: Some((H256::random(), 32)),
 			finalized: None,
@@ -536,7 +536,7 @@ mod test {
 
 		let authorities = vec![(AuthorityId::default(), 100)];
 		let set_id = 3;
-		let round_number: u64 = 42;
+		let round_number: RoundNumber = 42;
 		let round_state = RoundState::<H256, u64> {
 			prevote_ghost: Some((H256::random(), 32)),
 			finalized: None,
diff --git a/core/finality-grandpa/src/communication/gossip.rs b/core/finality-grandpa/src/communication/gossip.rs
index 5fd09620e925b..831be7ad14531 100644
--- a/core/finality-grandpa/src/communication/gossip.rs
+++ b/core/finality-grandpa/src/communication/gossip.rs
@@ -386,12 +386,14 @@ impl Misbehavior {
 
 struct PeerInfo<N> {
 	view: View<N>,
+	roles: Roles,
 }
 
 impl<N> PeerInfo<N> {
-	fn new() -> Self {
+	fn new(roles: Roles) -> Self {
 		PeerInfo {
 			view: View::default(),
+			roles,
 		}
 	}
 }
@@ -408,8 +410,8 @@ impl<N> Default for Peers<N> {
 }
 
 impl<N: Ord> Peers<N> {
-	fn new_peer(&mut self, who: PeerId) {
-		self.inner.insert(who, PeerInfo::new());
+	fn new_peer(&mut self, who: PeerId, roles: Roles) {
+		self.inner.insert(who, PeerInfo::new(roles));
 	}
 
 	fn peer_disconnected(&mut self, who: &PeerId) {
@@ -503,12 +505,13 @@ struct Inner<Block: BlockT> {
 	config: crate::Config,
 	next_rebroadcast: Instant,
 	pending_catch_up: PendingCatchUp,
+	catch_up_enabled: bool,
 }
 
 type MaybeMessage<Block> = Option<(Vec<PeerId>, NeighborPacket<NumberFor<Block>>)>;
 
 impl<Block: BlockT> Inner<Block> {
-	fn new(config: crate::Config) -> Self {
+	fn new(config: crate::Config, catch_up_enabled: bool) -> Self {
 		Inner {
 			local_view: None,
 			peers: Peers::default(),
@@ -516,6 +519,7 @@ impl<Block: BlockT> Inner<Block> {
 			next_rebroadcast: Instant::now() + REBROADCAST_AFTER,
 			authorities: Vec::new(),
 			pending_catch_up: PendingCatchUp::None,
+			catch_up_enabled,
 			config,
 		}
 	}
@@ -804,14 +808,21 @@ impl<Block: BlockT> Inner<Block> {
 	}
 
 	fn try_catch_up(&mut self, who: &PeerId) -> (Option<GossipMessage<Block>>, Option<Report>) {
+		if !self.catch_up_enabled {
+			return (None, None);
+		}
+
 		let mut catch_up = None;
 		let mut report = None;
 
 		// if the peer is on the same set and ahead of us by a margin bigger
 		// than `CATCH_UP_THRESHOLD` then we should ask it for a catch up
-		// message.
+		// message. we only send catch-up requests to authorities, observers
+		// won't be able to reply since they don't follow the full GRANDPA
+		// protocol and therefore might not have the vote data available.
 		if let (Some(peer), Some(local_view)) = (self.peers.peer(who), &self.local_view) {
-			if peer.view.set_id == local_view.set_id &&
+			if peer.roles.is_authority() &&
+				peer.view.set_id == local_view.set_id &&
 				peer.view.round.0.saturating_sub(CATCH_UP_THRESHOLD) > local_view.round.0
 			{
 				// send catch up request if allowed
@@ -917,13 +928,17 @@ pub(super) struct GossipValidator<Block: BlockT> {
 }
 
 impl<Block: BlockT> GossipValidator<Block> {
-	/// Create a new gossip-validator. This initialized the current set to 0.
-	pub(super) fn new(config: crate::Config, set_state: environment::SharedVoterSetState<Block>)
-		-> (GossipValidator<Block>, ReportStream)
-	{
+	/// Create a new gossip-validator. The current set is initialized to 0. If
+	/// `catch_up_enabled` is set to false then the validator will not issue any
+	/// catch up requests (useful e.g. when running just the GRANDPA observer).
+	pub(super) fn new(
+		config: crate::Config,
+		set_state: environment::SharedVoterSetState<Block>,
+		catch_up_enabled: bool,
+	) -> (GossipValidator<Block>, ReportStream)	{
 		let (tx, rx) = mpsc::unbounded();
 		let val = GossipValidator {
-			inner: parking_lot::RwLock::new(Inner::new(config)),
+			inner: parking_lot::RwLock::new(Inner::new(config, catch_up_enabled)),
 			set_state,
 			report_sender: tx,
 		};
@@ -1023,10 +1038,10 @@ impl<Block: BlockT> GossipValidator<Block> {
 }
 
 impl<Block: BlockT> network_gossip::Validator<Block> for GossipValidator<Block> {
-	fn new_peer(&self, context: &mut dyn ValidatorContext<Block>, who: &PeerId, _roles: Roles) {
+	fn new_peer(&self, context: &mut dyn ValidatorContext<Block>, who: &PeerId, roles: Roles) {
 		let packet = {
 			let mut inner = self.inner.write();
-			inner.peers.new_peer(who.clone());
+			inner.peers.new_peer(who.clone(), roles);
 
 			inner.local_view.as_ref().map(|v| {
 				NeighborPacket {
@@ -1314,7 +1329,7 @@ mod tests {
 		assert!(res.unwrap().is_none());
 
 		// connect & disconnect.
-		peers.new_peer(id.clone());
+		peers.new_peer(id.clone(), Roles::AUTHORITY);
 		peers.peer_disconnected(&id);
 
 		let res = peers.update_peer_state(&id, update.clone());
@@ -1350,7 +1365,7 @@ mod tests {
 		let mut peers = Peers::default();
 		let id = PeerId::random();
 
-		peers.new_peer(id.clone());
+		peers.new_peer(id.clone(), Roles::AUTHORITY);
 
 		let mut check_update = move |update: NeighborPacket<_>| {
 			let view = peers.update_peer_state(&id, update.clone()).unwrap().unwrap();
@@ -1370,7 +1385,7 @@ mod tests {
 		let mut peers = Peers::default();
 
 		let id = PeerId::random();
-		peers.new_peer(id.clone());
+		peers.new_peer(id.clone(), Roles::AUTHORITY);
 
 		peers.update_peer_state(&id, NeighborPacket {
 			round: Round(10),
@@ -1408,6 +1423,7 @@ mod tests {
 		let (val, _) = GossipValidator::<Block>::new(
 			config(),
 			voter_set_state(),
+			true,
 		);
 
 		let set_id = 1;
@@ -1443,6 +1459,7 @@ mod tests {
 		let (val, _) = GossipValidator::<Block>::new(
 			config(),
 			voter_set_state(),
+			true,
 		);
 		let set_id = 1;
 		let auth = AuthorityId::from_slice(&[1u8; 32]);
@@ -1487,6 +1504,7 @@ mod tests {
 		let (val, _) = GossipValidator::<Block>::new(
 			config(),
 			voter_set_state(),
+			true,
 		);
 
 		let set_id = 1;
@@ -1555,6 +1573,7 @@ mod tests {
 		let (val, _) = GossipValidator::<Block>::new(
 			config(),
 			set_state.clone(),
+			true,
 		);
 
 		let set_id = 1;
@@ -1567,7 +1586,7 @@ mod tests {
 		// add the peer making the request to the validator,
 		// otherwise it is discarded
 		let mut inner = val.inner.write();
-		inner.peers.new_peer(peer.clone());
+		inner.peers.new_peer(peer.clone(), Roles::AUTHORITY);
 
 		let res = inner.handle_catch_up_request(
 			&peer,
@@ -1609,6 +1628,7 @@ mod tests {
 		let (val, _) = GossipValidator::<Block>::new(
 			config(),
 			set_state.clone(),
+			true,
 		);
 
 		// the validator starts at set id 2
@@ -1617,7 +1637,7 @@ mod tests {
 		// add the peer making the request to the validator,
 		// otherwise it is discarded
 		let peer = PeerId::random();
-		val.inner.write().peers.new_peer(peer.clone());
+		val.inner.write().peers.new_peer(peer.clone(), Roles::AUTHORITY);
 
 		let send_request = |set_id, round| {
 			let mut inner = val.inner.write();
@@ -1682,4 +1702,151 @@ mod tests {
 			false,
 		);
 	}
+
+	#[test]
+	fn issues_catch_up_request_on_neighbor_packet_import() {
+		let (val, _) = GossipValidator::<Block>::new(
+			config(),
+			voter_set_state(),
+			true,
+		);
+
+		// the validator starts at set id 1.
+		val.note_set(SetId(1), Vec::new(), |_, _| {});
+
+		// add the peer making the request to the validator,
+		// otherwise it is discarded.
+		let peer = PeerId::random();
+		val.inner.write().peers.new_peer(peer.clone(), Roles::AUTHORITY);
+
+		let import_neighbor_message = |set_id, round| {
+			let (_, _, catch_up_request, _) = val.inner.write().import_neighbor_message(
+				&peer,
+				NeighborPacket {
+					round: Round(round),
+					set_id: SetId(set_id),
+					commit_finalized_height: 42,
+				},
+			);
+
+			catch_up_request
+		};
+
+		// importing a neighbor message from a peer in the same set in a later
+		// round should lead to a catch up request for the previous round.
+		match import_neighbor_message(1, 42) {
+			Some(GossipMessage::CatchUpRequest(request)) => {
+				assert_eq!(request.set_id, SetId(1));
+				assert_eq!(request.round, Round(41));
+			},
+			_ => panic!("expected catch up message"),
+		}
+
+		// we note that we're at round 41.
+		val.note_round(Round(41), |_, _| {});
+
+		// if we import a neighbor message within CATCH_UP_THRESHOLD then we
+		// won't request a catch up.
+		match import_neighbor_message(1, 42) {
+			None => {},
+			_ => panic!("expected no catch up message"),
+		}
+
+		// or if the peer is on a lower round.
+		match import_neighbor_message(1, 40) {
+			None => {},
+			_ => panic!("expected no catch up message"),
+		}
+
+		// we also don't request a catch up if the peer is in a different set.
+		match import_neighbor_message(2, 42) {
+			None => {},
+			_ => panic!("expected no catch up message"),
+		}
+	}
+
+	#[test]
+	fn doesnt_send_catch_up_requests_when_disabled() {
+		// we create a gossip validator with catch up requests disabled.
+		let (val, _) = GossipValidator::<Block>::new(
+			config(),
+			voter_set_state(),
+			false,
+		);
+
+		// the validator starts at set id 1.
+		val.note_set(SetId(1), Vec::new(), |_, _| {});
+
+		// add the peer making the request to the validator,
+		// otherwise it is discarded.
+		let peer = PeerId::random();
+		val.inner.write().peers.new_peer(peer.clone(), Roles::AUTHORITY);
+
+		// importing a neighbor message from a peer in the same set in a later
+		// round should lead to a catch up request but since they're disabled
+		// we should get `None`.
+		let (_, _, catch_up_request, _) = val.inner.write().import_neighbor_message(
+			&peer,
+			NeighborPacket {
+				round: Round(42),
+				set_id: SetId(1),
+				commit_finalized_height: 50,
+			},
+		);
+
+		match catch_up_request {
+			None => {},
+			_ => panic!("expected no catch up message"),
+		}
+	}
+
+	#[test]
+	fn doesnt_send_catch_up_requests_to_non_authorities() {
+		let (val, _) = GossipValidator::<Block>::new(
+			config(),
+			voter_set_state(),
+			true,
+		);
+
+		// the validator starts at set id 1.
+		val.note_set(SetId(1), Vec::new(), |_, _| {});
+
+		// add the peers making the requests to the validator,
+		// otherwise it is discarded.
+		let peer_authority = PeerId::random();
+		let peer_full = PeerId::random();
+
+		val.inner.write().peers.new_peer(peer_authority.clone(), Roles::AUTHORITY);
+		val.inner.write().peers.new_peer(peer_full.clone(), Roles::FULL);
+
+		let import_neighbor_message = |peer| {
+			let (_, _, catch_up_request, _) = val.inner.write().import_neighbor_message(
+				&peer,
+				NeighborPacket {
+					round: Round(42),
+					set_id: SetId(1),
+					commit_finalized_height: 50,
+				},
+			);
+
+			catch_up_request
+		};
+
+		// importing a neighbor message from a peer in the same set in a later
+		// round should lead to a catch up request but since the node is not an
+		// authority we should get `None`.
+		if import_neighbor_message(peer_full).is_some() {
+			panic!("expected no catch up message");
+		}
+
+		// importing the same neighbor message from a peer who is an authority
+		// should lead to a catch up request.
+		match import_neighbor_message(peer_authority) {
+			Some(GossipMessage::CatchUpRequest(request)) => {
+				assert_eq!(request.set_id, SetId(1));
+				assert_eq!(request.round, Round(41));
+			},
+			_ => panic!("expected catch up message"),
+		}
+	}
 }
diff --git a/core/finality-grandpa/src/communication/mod.rs b/core/finality-grandpa/src/communication/mod.rs
index 2aa2618535948..732c14c1a9ce3 100644
--- a/core/finality-grandpa/src/communication/mod.rs
+++ b/core/finality-grandpa/src/communication/mod.rs
@@ -50,7 +50,9 @@ use crate::environment::HasVoted;
 use gossip::{
 	GossipMessage, FullCatchUpMessage, FullCommitMessage, VoteOrPrecommitMessage, GossipValidator
 };
-use fg_primitives::{AuthorityPair, AuthorityId, AuthoritySignature};
+use fg_primitives::{
+	AuthorityPair, AuthorityId, AuthoritySignature, SetId as SetIdNumber, RoundNumber,
+};
 
 pub mod gossip;
 mod periodic;
@@ -129,12 +131,12 @@ pub trait Network<Block: BlockT>: Clone + Send + 'static {
 }
 
 /// Create a unique topic for a round and set-id combo.
-pub(crate) fn round_topic<B: BlockT>(round: u64, set_id: u64) -> B::Hash {
+pub(crate) fn round_topic<B: BlockT>(round: RoundNumber, set_id: SetIdNumber) -> B::Hash {
 	<<B::Header as HeaderT>::Hashing as HashT>::hash(format!("{}-{}", set_id, round).as_bytes())
 }
 
 /// Create a unique topic for global messages on a set ID.
-pub(crate) fn global_topic<B: BlockT>(set_id: u64) -> B::Hash {
+pub(crate) fn global_topic<B: BlockT>(set_id: SetIdNumber) -> B::Hash {
 	<<B::Header as HeaderT>::Hashing as HashT>::hash(format!("{}-GLOBAL", set_id).as_bytes())
 }
 
@@ -236,19 +238,25 @@ pub(crate) struct NetworkBridge<B: BlockT, N: Network<B>> {
 impl<B: BlockT, N: Network<B>> NetworkBridge<B, N> {
 	/// Create a new NetworkBridge to the given NetworkService. Returns the service
 	/// handle and a future that must be polled to completion to finish startup.
-	/// If a voter set state is given it registers previous round votes with the
-	/// gossip service.
+	/// On creation it will register previous rounds' votes with the gossip
+	/// service taken from the VoterSetState.
 	pub(crate) fn new(
 		service: N,
 		config: crate::Config,
 		set_state: crate::environment::SharedVoterSetState<B>,
 		on_exit: impl Future<Item=(),Error=()> + Clone + Send + 'static,
+		catch_up_enabled: bool,
 	) -> (
 		Self,
 		impl futures::Future<Item = (), Error = ()> + Send + 'static,
 	) {
 
-		let (validator, report_stream) = GossipValidator::new(config, set_state.clone());
+		let (validator, report_stream) = GossipValidator::new(
+			config,
+			set_state.clone(),
+			catch_up_enabled,
+		);
+
 		let validator = Arc::new(validator);
 		service.register_validator(validator.clone());
 
@@ -612,25 +620,25 @@ impl<B: BlockT, N: Network<B>> Clone for NetworkBridge<B, N> {
 	}
 }
 
-fn localized_payload<E: Encode>(round: u64, set_id: u64, message: &E) -> Vec<u8> {
+fn localized_payload<E: Encode>(round: RoundNumber, set_id: SetIdNumber, message: &E) -> Vec<u8> {
 	(message, round, set_id).encode()
 }
 
-/// Type-safe wrapper around u64 when indicating that it's a round number.
+/// Type-safe wrapper around a round number.
 #[derive(Debug, Clone, Copy, Eq, PartialEq, PartialOrd, Ord, Encode, Decode)]
-pub struct Round(pub u64);
+pub struct Round(pub RoundNumber);
 
-/// Type-safe wrapper around u64 when indicating that it's a set ID.
+/// Type-safe wrapper around a set ID.
 #[derive(Debug, Clone, Copy, Eq, PartialEq, PartialOrd, Ord, Encode, Decode)]
-pub struct SetId(pub u64);
+pub struct SetId(pub SetIdNumber);
 
 // check a message.
 pub(crate) fn check_message_sig<Block: BlockT>(
 	message: &Message<Block>,
 	id: &AuthorityId,
 	signature: &AuthoritySignature,
-	round: u64,
-	set_id: u64,
+	round: RoundNumber,
+	set_id: SetIdNumber,
 ) -> Result<(), ()> {
 	let as_public = id.clone();
 	let encoded_raw = localized_payload(round, set_id, message);
@@ -650,8 +658,8 @@ pub(crate) fn check_message_sig<Block: BlockT>(
 /// `ed25519` and `BLS` signatures (which we might use in the future), care must
 /// be taken when switching to different key types.
 struct OutgoingMessages<Block: BlockT, N: Network<Block>> {
-	round: u64,
-	set_id: u64,
+	round: RoundNumber,
+	set_id: SetIdNumber,
 	locals: Option<(AuthorityPair, AuthorityId)>,
 	sender: mpsc::UnboundedSender<SignedMessage<Block>>,
 	network: N,
@@ -845,8 +853,8 @@ fn check_catch_up<Block: BlockT>(
 
 	fn check_signatures<'a, B, I>(
 		messages: I,
-		round: u64,
-		set_id: u64,
+		round: RoundNumber,
+		set_id: SetIdNumber,
 		mut signatures_checked: usize,
 	) -> Result<usize, i32> where
 		B: BlockT,
@@ -913,7 +921,7 @@ impl<Block: BlockT, N: Network<Block>> CommitsOut<Block, N> {
 	/// Create a new commit output stream.
 	pub(crate) fn new(
 		network: N,
-		set_id: u64,
+		set_id: SetIdNumber,
 		is_voter: bool,
 		gossip_validator: Arc<GossipValidator<Block>>,
 	) -> Self {
@@ -927,10 +935,10 @@ impl<Block: BlockT, N: Network<Block>> CommitsOut<Block, N> {
 }
 
 impl<Block: BlockT, N: Network<Block>> Sink for CommitsOut<Block, N> {
-	type SinkItem = (u64, Commit<Block>);
+	type SinkItem = (RoundNumber, Commit<Block>);
 	type SinkError = Error;
 
-	fn start_send(&mut self, input: (u64, Commit<Block>)) -> StartSend<Self::SinkItem, Error> {
+	fn start_send(&mut self, input: (RoundNumber, Commit<Block>)) -> StartSend<Self::SinkItem, Error> {
 		if !self.is_voter {
 			return Ok(AsyncSink::Ready);
 		}
diff --git a/core/finality-grandpa/src/communication/tests.rs b/core/finality-grandpa/src/communication/tests.rs
index de5a084039268..b537c29dcab9c 100644
--- a/core/finality-grandpa/src/communication/tests.rs
+++ b/core/finality-grandpa/src/communication/tests.rs
@@ -182,6 +182,7 @@ fn make_test_network() -> (
 		config(),
 		voter_set_state(),
 		Exit,
+		true,
 	);
 
 	(
@@ -447,8 +448,8 @@ fn peer_with_higher_view_leads_to_catch_up_request() {
 	let (tester, mut net) = make_test_network();
 	let test = tester
 		.and_then(move |tester| {
-			// register a peer.
-			tester.gossip_validator.new_peer(&mut NoopContext, &id, network::config::Roles::FULL);
+			// register a peer with authority role.
+			tester.gossip_validator.new_peer(&mut NoopContext, &id, network::config::Roles::AUTHORITY);
 			Ok((tester, id))
 		})
 		.and_then(move |(tester, id)| {
diff --git a/core/finality-grandpa/src/environment.rs b/core/finality-grandpa/src/environment.rs
index b20e8ab5dfcbb..c0474cb0368c8 100644
--- a/core/finality-grandpa/src/environment.rs
+++ b/core/finality-grandpa/src/environment.rs
@@ -51,7 +51,7 @@ use crate::authorities::{AuthoritySet, SharedAuthoritySet};
 use crate::consensus_changes::SharedConsensusChanges;
 use crate::justification::GrandpaJustification;
 use crate::until_imported::UntilVoteTargetImported;
-use fg_primitives::{AuthorityId, AuthoritySignature};
+use fg_primitives::{AuthorityId, AuthoritySignature, SetId, RoundNumber};
 
 type HistoricalVotes<Block> = grandpa::HistoricalVotes<
 	<Block as BlockT>::Hash,
@@ -65,7 +65,7 @@ type HistoricalVotes<Block> = grandpa::HistoricalVotes<
 #[derive(Debug, Clone, Decode, Encode, PartialEq)]
 pub struct CompletedRound<Block: BlockT> {
 	/// The round number.
-	pub number: u64,
+	pub number: RoundNumber,
 	/// The round state (prevote ghost, estimate, finalized, etc.)
 	pub state: RoundState<Block::Hash, NumberFor<Block>>,
 	/// The target block base used for voting in the round.
@@ -80,7 +80,7 @@ pub struct CompletedRound<Block: BlockT> {
 #[derive(Debug, Clone, PartialEq)]
 pub struct CompletedRounds<Block: BlockT> {
 	rounds: Vec<CompletedRound<Block>>,
-	set_id: u64,
+	set_id: SetId,
 	voters: Vec<AuthorityId>,
 }
 
@@ -100,7 +100,7 @@ impl<Block: BlockT> codec::EncodeLike for CompletedRounds<Block> {}
 
 impl<Block: BlockT> Decode for CompletedRounds<Block> {
 	fn decode<I: codec::Input>(value: &mut I) -> Result<Self, codec::Error> {
-		<(Vec<CompletedRound<Block>>, u64, Vec<AuthorityId>)>::decode(value)
+		<(Vec<CompletedRound<Block>>, SetId, Vec<AuthorityId>)>::decode(value)
 			.map(|(rounds, set_id, voters)| CompletedRounds {
 				rounds: rounds.into(),
 				set_id,
@@ -113,7 +113,7 @@ impl<Block: BlockT> CompletedRounds<Block> {
 	/// Create a new completed rounds tracker with NUM_LAST_COMPLETED_ROUNDS capacity.
 	pub(crate) fn new(
 		genesis: CompletedRound<Block>,
-		set_id: u64,
+		set_id: SetId,
 		voters: &AuthoritySet<Block::Hash, NumberFor<Block>>,
 	)
 		-> CompletedRounds<Block>
@@ -126,7 +126,7 @@ impl<Block: BlockT> CompletedRounds<Block> {
 	}
 
 	/// Get the set-id and voter set of the completed rounds.
-	pub fn set_info(&self) -> (u64, &[AuthorityId]) {
+	pub fn set_info(&self) -> (SetId, &[AuthorityId]) {
 		(self.set_id, &self.voters[..])
 	}
 
@@ -162,7 +162,7 @@ impl<Block: BlockT> CompletedRounds<Block> {
 
 /// A map with voter status information for currently live rounds,
 /// which votes have we cast and what are they.
-pub type CurrentRounds<Block> = BTreeMap<u64, HasVoted<Block>>;
+pub type CurrentRounds<Block> = BTreeMap<RoundNumber, HasVoted<Block>>;
 
 /// The state of the current voter set, whether it is currently active or not
 /// and information related to the previously completed rounds. Current round
@@ -190,7 +190,7 @@ impl<Block: BlockT> VoterSetState<Block> {
 	/// the given genesis state and the given authorities. Round 1 is added as a
 	/// current round (with state `HasVoted::No`).
 	pub(crate) fn live(
-		set_id: u64,
+		set_id: SetId,
 		authority_set: &AuthoritySet<Block::Hash, NumberFor<Block>>,
 		genesis_state: (Block::Hash, NumberFor<Block>),
 	) -> VoterSetState<Block> {
@@ -237,7 +237,7 @@ impl<Block: BlockT> VoterSetState<Block> {
 
 	/// Returns the voter set state validating that it includes the given round
 	/// in current rounds and that the voter isn't paused.
-	pub fn with_current_round(&self, round: u64)
+	pub fn with_current_round(&self, round: RoundNumber)
 		-> Result<(&CompletedRounds<Block>, &CurrentRounds<Block>), Error>
 	{
 		if let VoterSetState::Live { completed_rounds, current_rounds } = self {
@@ -344,7 +344,7 @@ impl<Block: BlockT> SharedVoterSetState<Block> {
 	}
 
 	/// Return vote status information for the current round.
-	pub(crate) fn has_voted(&self, round: u64) -> HasVoted<Block> {
+	pub(crate) fn has_voted(&self, round: RoundNumber) -> HasVoted<Block> {
 		match &*self.inner.read() {
 			VoterSetState::Live { current_rounds, .. } => {
 				current_rounds.get(&round).and_then(|has_voted| match has_voted {
@@ -375,7 +375,7 @@ pub(crate) struct Environment<B, E, Block: BlockT, N: Network<Block>, RA, SC> {
 	pub(crate) authority_set: SharedAuthoritySet<Block::Hash, NumberFor<Block>>,
 	pub(crate) consensus_changes: SharedConsensusChanges<Block::Hash, NumberFor<Block>>,
 	pub(crate) network: crate::communication::NetworkBridge<Block, N>,
-	pub(crate) set_id: u64,
+	pub(crate) set_id: SetId,
 	pub(crate) voter_set_state: SharedVoterSetState<Block>,
 }
 
@@ -554,7 +554,7 @@ where
 
 	fn round_data(
 		&self,
-		round: u64
+		round: RoundNumber,
 	) -> voter::RoundData<Self::Id, Self::Timer, Self::In, Self::Out> {
 		let now = Instant::now();
 		let prevote_timer = Delay::new(now + self.config.gossip_duration * 2);
@@ -601,7 +601,7 @@ where
 		}
 	}
 
-	fn proposed(&self, round: u64, propose: PrimaryPropose<Block>) -> Result<(), Self::Error> {
+	fn proposed(&self, round: RoundNumber, propose: PrimaryPropose<Block>) -> Result<(), Self::Error> {
 		let local_id = crate::is_voter(&self.voters, &self.config.keystore);
 
 		let local_id = match local_id {
@@ -641,7 +641,7 @@ where
 		Ok(())
 	}
 
-	fn prevoted(&self, round: u64, prevote: Prevote<Block>) -> Result<(), Self::Error> {
+	fn prevoted(&self, round: RoundNumber, prevote: Prevote<Block>) -> Result<(), Self::Error> {
 		let local_id = crate::is_voter(&self.voters, &self.config.keystore);
 
 		let local_id = match local_id {
@@ -683,7 +683,7 @@ where
 		Ok(())
 	}
 
-	fn precommitted(&self, round: u64, precommit: Precommit<Block>) -> Result<(), Self::Error> {
+	fn precommitted(&self, round: RoundNumber, precommit: Precommit<Block>) -> Result<(), Self::Error> {
 		let local_id = crate::is_voter(&self.voters, &self.config.keystore);
 
 		let local_id = match local_id {
@@ -737,7 +737,7 @@ where
 
 	fn completed(
 		&self,
-		round: u64,
+		round: RoundNumber,
 		state: RoundState<Block::Hash, NumberFor<Block>>,
 		base: (Block::Hash, NumberFor<Block>),
 		historical_votes: &HistoricalVotes<Block>,
@@ -794,7 +794,13 @@ where
 		Ok(())
 	}
 
-	fn finalize_block(&self, hash: Block::Hash, number: NumberFor<Block>, round: u64, commit: Commit<Block>) -> Result<(), Self::Error> {
+	fn finalize_block(
+		&self,
+		hash: Block::Hash,
+		number: NumberFor<Block>,
+		round: RoundNumber,
+		commit: Commit<Block>,
+	) -> Result<(), Self::Error> {
 		finalize_block(
 			&*self.inner,
 			&self.authority_set,
@@ -818,7 +824,7 @@ where
 
 	fn prevote_equivocation(
 		&self,
-		_round: u64,
+		_round: RoundNumber,
 		equivocation: ::grandpa::Equivocation<Self::Id, Prevote<Block>, Self::Signature>
 	) {
 		warn!(target: "afg", "Detected prevote equivocation in the finality worker: {:?}", equivocation);
@@ -827,7 +833,7 @@ where
 
 	fn precommit_equivocation(
 		&self,
-		_round: u64,
+		_round: RoundNumber,
 		equivocation: Equivocation<Self::Id, Precommit<Block>, Self::Signature>
 	) {
 		warn!(target: "afg", "Detected precommit equivocation in the finality worker: {:?}", equivocation);
@@ -837,11 +843,11 @@ where
 
 pub(crate) enum JustificationOrCommit<Block: BlockT> {
 	Justification(GrandpaJustification<Block>),
-	Commit((u64, Commit<Block>)),
+	Commit((RoundNumber, Commit<Block>)),
 }
 
-impl<Block: BlockT> From<(u64, Commit<Block>)> for JustificationOrCommit<Block> {
-	fn from(commit: (u64, Commit<Block>)) -> JustificationOrCommit<Block> {
+impl<Block: BlockT> From<(RoundNumber, Commit<Block>)> for JustificationOrCommit<Block> {
+	fn from(commit: (RoundNumber, Commit<Block>)) -> JustificationOrCommit<Block> {
 		JustificationOrCommit::Commit(commit)
 	}
 }
diff --git a/core/finality-grandpa/src/lib.rs b/core/finality-grandpa/src/lib.rs
index 428fa1aeb8232..d6f4d768472a3 100644
--- a/core/finality-grandpa/src/lib.rs
+++ b/core/finality-grandpa/src/lib.rs
@@ -93,10 +93,6 @@ mod light_import;
 mod observer;
 mod until_imported;
 
-#[cfg(feature="service-integration")]
-mod service_integration;
-#[cfg(feature="service-integration")]
-pub use service_integration::{LinkHalfForService, BlockImportForService, BlockImportForLightService};
 pub use communication::Network;
 pub use finality_proof::FinalityProofProvider;
 pub use light_import::light_block_import;
@@ -107,8 +103,7 @@ use environment::{Environment, VoterSetState};
 use import::GrandpaBlockImport;
 use until_imported::UntilGlobalMessageBlocksImported;
 use communication::NetworkBridge;
-use service::TelemetryOnConnect;
-use fg_primitives::AuthoritySignature;
+use fg_primitives::{AuthoritySignature, SetId, AuthorityWeight};
 
 // Re-export these two because it's just so damn convenient.
 pub use fg_primitives::{AuthorityId, ScheduledChange};
@@ -267,8 +262,8 @@ impl<B, E, Block: BlockT<Hash=H256>, RA> BlockStatus<Block> for Arc<Client<B, E,
 pub(crate) struct NewAuthoritySet<H, N> {
 	pub(crate) canon_number: N,
 	pub(crate) canon_hash: H,
-	pub(crate) set_id: u64,
-	pub(crate) authorities: Vec<(AuthorityId, u64)>,
+	pub(crate) set_id: SetId,
+	pub(crate) authorities: Vec<(AuthorityId, AuthorityWeight)>,
 }
 
 /// Commands issued to the voter.
@@ -399,7 +394,7 @@ where
 }
 
 fn global_communication<Block: BlockT<Hash=H256>, B, E, N, RA>(
-	set_id: u64,
+	set_id: SetId,
 	voters: &Arc<VoterSet<AuthorityId>>,
 	client: &Arc<Client<B, E, Block, RA>>,
 	network: &NetworkBridge<Block, N>,
@@ -484,7 +479,7 @@ pub struct GrandpaParams<B, E, Block: BlockT<Hash=H256>, N, RA, SC, X> {
 	/// Handle to a future that will resolve on exit.
 	pub on_exit: X,
 	/// If supplied, can be used to hook on telemetry connection established events.
-	pub telemetry_on_connect: Option<TelemetryOnConnect>,
+	pub telemetry_on_connect: Option<mpsc::UnboundedReceiver<()>>,
 }
 
 /// Run a GRANDPA voter as a task. Provide configuration and a link to a
@@ -524,13 +519,14 @@ pub fn run_grandpa_voter<B, E, Block: BlockT<Hash=H256>, N, RA, SC, X>(
 		config.clone(),
 		persistent_data.set_state.clone(),
 		on_exit.clone(),
+		true,
 	);
 
 	register_finality_tracker_inherent_data_provider(client.clone(), &inherent_data_providers)?;
 
 	let telemetry_task = if let Some(telemetry_on_connect) = telemetry_on_connect {
 		let authorities = persistent_data.authority_set.clone();
-		let events = telemetry_on_connect.telemetry_connection_sinks
+		let events = telemetry_on_connect
 			.for_each(move |_| {
 				telemetry!(CONSENSUS_INFO; "afg.authority_set";
 					 "authority_set_id" => ?authorities.set_id(),
diff --git a/core/finality-grandpa/src/light_import.rs b/core/finality-grandpa/src/light_import.rs
index dbdabe96294b1..4d5381f1cc4b2 100644
--- a/core/finality-grandpa/src/light_import.rs
+++ b/core/finality-grandpa/src/light_import.rs
@@ -36,7 +36,7 @@ use sr_primitives::Justification;
 use sr_primitives::traits::{
 	NumberFor, Block as BlockT, Header as HeaderT, ProvideRuntimeApi, DigestFor,
 };
-use fg_primitives::{GrandpaApi, AuthorityId};
+use fg_primitives::{self, GrandpaApi, AuthorityId};
 use sr_primitives::generic::BlockId;
 use primitives::{H256, Blake2Hasher};
 
@@ -192,7 +192,7 @@ impl LightAuthoritySet {
 	/// Get a genesis set with given authorities.
 	pub fn genesis(initial: Vec<(AuthorityId, u64)>) -> Self {
 		LightAuthoritySet {
-			set_id: 0,
+			set_id: fg_primitives::SetId::default(),
 			authorities: initial,
 		}
 	}
diff --git a/core/finality-grandpa/src/observer.rs b/core/finality-grandpa/src/observer.rs
index bce292262e028..8a2d539f49694 100644
--- a/core/finality-grandpa/src/observer.rs
+++ b/core/finality-grandpa/src/observer.rs
@@ -175,8 +175,10 @@ pub fn run_grandpa_observer<B, E, Block: BlockT<Hash=H256>, N, RA, SC>(
 		network,
 		config.clone(),
 		persistent_data.set_state.clone(),
-		on_exit.clone()
+		on_exit.clone(),
+		false,
 	);
+
 	let observer_work = ObserverWork::new(
 		client,
 		network,
diff --git a/core/finality-grandpa/src/service_integration.rs b/core/finality-grandpa/src/service_integration.rs
deleted file mode 100644
index 9f19b9204190b..0000000000000
--- a/core/finality-grandpa/src/service_integration.rs
+++ /dev/null
@@ -1,49 +0,0 @@
-// Copyright 2018-2019 Parity Technologies (UK) Ltd.
-// This file is part of Substrate.
-
-// Substrate is free software: you can redistribute it and/or modify
-// it under the terms of the GNU General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-
-// Substrate is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU General Public License for more details.
-
-// You should have received a copy of the GNU General Public License
-// along with Substrate.  If not, see <http://www.gnu.org/licenses/>.
-
-/// Integrate grandpa finality with substrate service
-
-use client;
-use service::{FullBackend, FullExecutor, LightBackend, LightExecutor, ServiceFactory};
-
-pub type BlockImportForService<F> = crate::GrandpaBlockImport<
-	FullBackend<F>,
-	FullExecutor<F>,
-	<F as ServiceFactory>::Block,
-	<F as ServiceFactory>::RuntimeApi,
-	client::Client<
-		FullBackend<F>,
-		FullExecutor<F>,
-		<F as ServiceFactory>::Block,
-		<F as ServiceFactory>::RuntimeApi
-	>,
-	<F as ServiceFactory>::SelectChain,
->;
-
-pub type LinkHalfForService<F> = crate::LinkHalf<
-	FullBackend<F>,
-	FullExecutor<F>,
-	<F as ServiceFactory>::Block,
-	<F as ServiceFactory>::RuntimeApi,
-	<F as ServiceFactory>::SelectChain
->;
-
-pub type BlockImportForLightService<F> = crate::light_import::GrandpaLightBlockImport<
-	LightBackend<F>,
-	LightExecutor<F>,
-	<F as ServiceFactory>::Block,
-	<F as ServiceFactory>::RuntimeApi,
->;
diff --git a/core/finality-grandpa/src/tests.rs b/core/finality-grandpa/src/tests.rs
index f634fd114ae3d..c82982e20d494 100644
--- a/core/finality-grandpa/src/tests.rs
+++ b/core/finality-grandpa/src/tests.rs
@@ -1215,6 +1215,7 @@ fn voter_persists_its_votes() {
 			config.clone(),
 			set_state,
 			Exit,
+			true,
 		);
 		runtime.block_on(routing_work).unwrap();
 
diff --git a/core/offchain/Cargo.toml b/core/offchain/Cargo.toml
index 4c8891eb6b14c..691fdea91cc48 100644
--- a/core/offchain/Cargo.toml
+++ b/core/offchain/Cargo.toml
@@ -7,13 +7,20 @@ authors = ["Parity Technologies <admin@parity.io>"]
 edition = "2018"
 
 [dependencies]
+bytes = "0.4"
 client = { package = "substrate-client", path = "../../core/client" }
+fnv = "1.0"
+futures01 = { package = "futures", version = "0.1" }
 futures-preview = "=0.3.0-alpha.17"
+futures-timer = "0.2.1"
+hyper = "0.12.33"
+hyper-tls = "0.3.2"
 log = "0.4"
 offchain-primitives = { package = "substrate-offchain-primitives", path = "./primitives" }
 codec = { package = "parity-scale-codec", version = "1.0.0", features = ["derive"] }
 parking_lot = "0.9.0"
 primitives = { package = "substrate-primitives", path = "../../core/primitives" }
+rand = "0.7"
 sr-primitives = { path = "../../core/sr-primitives" }
 transaction_pool = { package = "substrate-transaction-pool", path = "../../core/transaction-pool" }
 network = { package = "substrate-network", path = "../../core/network" }
@@ -23,6 +30,7 @@ keystore = { package = "substrate-keystore", path = "../keystore" }
 env_logger = "0.6"
 client-db = { package = "substrate-client-db", path = "../../core/client/db/", default-features = true }
 test-client = { package = "substrate-test-runtime-client", path = "../../core/test-runtime/client" }
+tokio = "0.1"
 
 [features]
 default = []
diff --git a/core/offchain/src/api.rs b/core/offchain/src/api.rs
index 225e7c3f725a4..0057dfd273b8b 100644
--- a/core/offchain/src/api.rs
+++ b/core/offchain/src/api.rs
@@ -17,13 +17,12 @@
 use std::{
 	str::FromStr,
 	sync::Arc,
-	convert::{TryFrom, TryInto},
-	time::{SystemTime, Duration},
+	convert::TryFrom,
 	thread::sleep,
 };
 
 use client::backend::OffchainStorage;
-use futures::{StreamExt as _, Future, future, channel::mpsc};
+use futures::{StreamExt as _, Future, FutureExt as _, future, channel::mpsc};
 use log::{info, debug, warn, error};
 use network::{PeerId, Multiaddr, NetworkStateInfo};
 use codec::{Encode, Decode};
@@ -34,6 +33,9 @@ use primitives::offchain::{
 use sr_primitives::{generic::BlockId, traits::{self, Extrinsic}};
 use transaction_pool::txpool::{Pool, ChainApi};
 
+mod http;
+mod timestamp;
+
 /// A message between the offchain extension and the processing thread.
 enum ExtMessage {
 	SubmitExtrinsic(Vec<u8>),
@@ -49,6 +51,8 @@ pub(crate) struct Api<Storage, Block: traits::Block> {
 	_at: BlockId<Block>,
 	/// Is this node a potential validator?
 	is_validator: bool,
+	/// Everything HTTP-related is handled by a different struct.
+	http: http::HttpApi,
 }
 
 fn unavailable_yet<R: Default>(name: &str) -> R {
@@ -89,29 +93,11 @@ where
 	}
 
 	fn timestamp(&mut self) -> Timestamp {
-		let now = SystemTime::now();
-		let epoch_duration = now.duration_since(SystemTime::UNIX_EPOCH);
-		match epoch_duration {
-			Err(_) => {
-				// Current time is earlier than UNIX_EPOCH.
-				Timestamp::from_unix_millis(0)
-			},
-			Ok(d) => {
-				let duration = d.as_millis();
-				// Assuming overflow won't happen for a few hundred years.
-				Timestamp::from_unix_millis(duration.try_into()
-					.expect("epoch milliseconds won't overflow u64 for hundreds of years; qed"))
-			}
-		}
+		timestamp::now()
 	}
 
 	fn sleep_until(&mut self, deadline: Timestamp) {
-		// Get current timestamp.
-		let now = self.timestamp();
-		// Calculate the diff with the deadline.
-		let diff = deadline.diff(&now);
-		// Call thread::sleep for the diff duration.
-		sleep(Duration::from_millis(diff.millis()));
+		sleep(timestamp::timestamp_from_now(deadline));
 	}
 
 	fn random_seed(&mut self) -> [u8; 32] {
@@ -149,58 +135,53 @@ where
 
 	fn http_request_start(
 		&mut self,
-		_method: &str,
-		_uri: &str,
+		method: &str,
+		uri: &str,
 		_meta: &[u8]
 	) -> Result<HttpRequestId, ()> {
-		unavailable_yet::<()>("http_request_start");
-		Err(())
+		self.http.request_start(method, uri)
 	}
 
 	fn http_request_add_header(
 		&mut self,
-		_request_id: HttpRequestId,
-		_name: &str,
-		_value: &str
+		request_id: HttpRequestId,
+		name: &str,
+		value: &str
 	) -> Result<(), ()> {
-		unavailable_yet::<()>("http_request_add_header");
-		Err(())
+		self.http.request_add_header(request_id, name, value)
 	}
 
 	fn http_request_write_body(
 		&mut self,
-		_request_id: HttpRequestId,
-		_chunk: &[u8],
-		_deadline: Option<Timestamp>
+		request_id: HttpRequestId,
+		chunk: &[u8],
+		deadline: Option<Timestamp>
 	) -> Result<(), HttpError> {
-		unavailable_yet::<()>("http_request_write_body");
-		Err(HttpError::IoError)
+		self.http.request_write_body(request_id, chunk, deadline)
 	}
 
 	fn http_response_wait(
 		&mut self,
 		ids: &[HttpRequestId],
-		_deadline: Option<Timestamp>
+		deadline: Option<Timestamp>
 	) -> Vec<HttpRequestStatus> {
-		unavailable_yet::<()>("http_response_wait");
-		ids.iter().map(|_| HttpRequestStatus::Unknown).collect()
+		self.http.response_wait(ids, deadline)
 	}
 
 	fn http_response_headers(
 		&mut self,
-		_request_id: HttpRequestId
+		request_id: HttpRequestId
 	) -> Vec<(Vec<u8>, Vec<u8>)> {
-		unavailable_yet("http_response_headers")
+		self.http.response_headers(request_id)
 	}
 
 	fn http_response_read_body(
 		&mut self,
-		_request_id: HttpRequestId,
-		_buffer: &mut [u8],
-		_deadline: Option<Timestamp>
+		request_id: HttpRequestId,
+		buffer: &mut [u8],
+		deadline: Option<Timestamp>
 	) -> Result<usize, HttpError> {
-		unavailable_yet::<()>("http_response_read_body");
-		Err(HttpError::IoError)
+		self.http.response_read_body(request_id, buffer, deadline)
 	}
 }
 
@@ -276,6 +257,8 @@ pub(crate) struct AsyncApi<A: ChainApi> {
 	receiver: Option<mpsc::UnboundedReceiver<ExtMessage>>,
 	transaction_pool: Arc<Pool<A>>,
 	at: BlockId<A::Block>,
+	/// Everything HTTP-related is handled by a different struct.
+	http: Option<http::HttpWorker>,
 }
 
 impl<A: ChainApi> AsyncApi<A> {
@@ -289,18 +272,22 @@ impl<A: ChainApi> AsyncApi<A> {
 	) -> (Api<S, A::Block>, AsyncApi<A>) {
 		let (sender, rx) = mpsc::unbounded();
 
+		let (http_api, http_worker) = http::http();
+
 		let api = Api {
 			sender,
 			db,
 			network_state,
 			_at: at,
 			is_validator,
+			http: http_api,
 		};
 
 		let async_api = AsyncApi {
 			receiver: Some(rx),
 			transaction_pool,
 			at,
+			http: Some(http_worker),
 		};
 
 		(api, async_api)
@@ -309,13 +296,17 @@ impl<A: ChainApi> AsyncApi<A> {
 	/// Run a processing task for the API
 	pub fn process(mut self) -> impl Future<Output = ()> {
 		let receiver = self.receiver.take().expect("Take invoked only once.");
+		let http = self.http.take().expect("Take invoked only once.");
 
-		receiver.for_each(move |msg| {
+		let extrinsics = receiver.for_each(move |msg| {
 			match msg {
 				ExtMessage::SubmitExtrinsic(ext) => self.submit_extrinsic(ext),
 			}
 			future::ready(())
-		})
+		});
+
+		future::join(extrinsics, http)
+			.map(|((), ())| ())
 	}
 
 	fn submit_extrinsic(&mut self, ext: Vec<u8>) {
@@ -340,7 +331,7 @@ impl<A: ChainApi> AsyncApi<A> {
 #[cfg(test)]
 mod tests {
 	use super::*;
-	use std::convert::TryFrom;
+	use std::{convert::{TryFrom, TryInto}, time::SystemTime};
 	use sr_primitives::traits::Zero;
 	use client_db::offchain::LocalStorage;
 	use network::PeerId;
diff --git a/core/offchain/src/api/http.rs b/core/offchain/src/api/http.rs
new file mode 100644
index 0000000000000..9ea666862c3d9
--- /dev/null
+++ b/core/offchain/src/api/http.rs
@@ -0,0 +1,1004 @@
+// Copyright 2019 Parity Technologies (UK) Ltd.
+// This file is part of Substrate.
+
+// Substrate is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Substrate is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Substrate.  If not, see <http://www.gnu.org/licenses/>.
+
+//! This module is composed of two structs: [`HttpApi`] and [`HttpWorker`]. Calling the [`http`]
+//! function returns a pair of [`HttpApi`] and [`HttpWorker`] that share some state.
+//!
+//! The [`HttpApi`] is (indirectly) passed to the runtime when calling an offchain worker, while
+//! the [`HttpWorker`] must be processed in the background. The [`HttpApi`] mimicks the API of the
+//! HTTP-related methods available to offchain workers.
+//!
+//! The reason for this design is driven by the fact that HTTP requests should continue running
+//! (i.e.: the socket should continue being processed) in the background even if the runtime isn't
+//! actively calling any function.
+
+use crate::api::timestamp;
+use bytes::Buf as _;
+use fnv::FnvHashMap;
+use futures::{prelude::*, channel::mpsc, compat::Compat01As03};
+use log::{warn, error};
+use primitives::offchain::{HttpRequestId, Timestamp, HttpRequestStatus, HttpError};
+use std::{fmt, io::Read as _, mem, pin::Pin, task::Context, task::Poll};
+
+/// Creates a pair of [`HttpApi`] and [`HttpWorker`].
+pub fn http() -> (HttpApi, HttpWorker) {
+	let (to_worker, from_api) = mpsc::unbounded();
+	let (to_api, from_worker) = mpsc::unbounded();
+
+	let api = HttpApi {
+		to_worker,
+		from_worker: from_worker.fuse(),
+		// We start with a random ID for the first HTTP request, to prevent mischievous people from
+		// writing runtime code with hardcoded IDs.
+		next_id: HttpRequestId(rand::random::<u16>() % 2000),
+		requests: FnvHashMap::default(),
+	};
+
+	let engine = HttpWorker {
+		to_api,
+		from_api,
+		// TODO: don't unwrap; we should fall back to the HttpConnector if we fail to create the
+		// Https one; there doesn't seem to be any built-in way to do this
+		http_client: HyperClient::new(),
+		requests: Vec::new(),
+	};
+
+	(api, engine)
+}
+
+/// Provides HTTP capabilities.
+///
+/// Since this struct is a helper for offchain workers, its API is mimicking the API provided
+/// to offchain workers.
+pub struct HttpApi {
+	/// Used to sends messages to the worker.
+	to_worker: mpsc::UnboundedSender<ApiToWorker>,
+	/// Used to receive messages from the worker.
+	/// We use a `Fuse` in order to have an extra protection against panicking.
+	from_worker: stream::Fuse<mpsc::UnboundedReceiver<WorkerToApi>>,
+	/// Id to assign to the next HTTP request that is started.
+	next_id: HttpRequestId,
+	/// List of HTTP requests in preparation or in progress.
+	requests: FnvHashMap<HttpRequestId, HttpApiRequest>,
+}
+
+/// One active request within `HttpApi`.
+enum HttpApiRequest {
+	/// The request object is being constructed locally and not started yet.
+	NotDispatched(hyper::Request<hyper::Body>, hyper::body::Sender),
+	/// The request has been dispatched and we're in the process of sending out the body (if the
+	/// field is `Some`) or waiting for a response (if the field is `None`).
+	Dispatched(Option<hyper::body::Sender>),
+	/// Received a response.
+	Response(HttpApiRequestRp),
+	/// A request has been dispatched but the worker notified us of an error. We report this
+	/// failure to the user as an `IoError` and remove the request from the list as soon as
+	/// possible.
+	Fail(hyper::Error),
+}
+
+/// A request within `HttpApi` that has received a response.
+struct HttpApiRequestRp {
+	/// We might still be writing the request's body when the response comes.
+	/// This field allows to continue writing that body.
+	sending_body: Option<hyper::body::Sender>,
+	/// Status code of the response.
+	status_code: hyper::StatusCode,
+	/// Headers of the response.
+	headers: hyper::HeaderMap,
+	/// Body of the response, as a channel of `Chunk` objects.
+	/// While the code is designed to drop the `Receiver` once it ends, we wrap it within a
+	/// `Fuse` in order to be extra precautious about panics.
+	/// Elements extracted from the channel are first put into `current_read_chunk`.
+	/// If the channel produces an error, then that is translated into an `IoError` and the request
+	/// is removed from the list.
+	body: stream::Fuse<mpsc::Receiver<Result<hyper::Chunk, hyper::Error>>>,
+	/// Chunk that has been extracted from the channel and that is currently being read.
+	/// Reading data from the response should read from this field in priority.
+	current_read_chunk: Option<bytes::Reader<hyper::Chunk>>,
+}
+
+impl HttpApi {
+	/// Mimicks the corresponding method in the offchain API.
+	pub fn request_start(
+		&mut self,
+		method: &str,
+		uri: &str
+	) -> Result<HttpRequestId, ()> {
+		// Start by building the prototype of the request.
+		// We do this first so that we don't touch anything in `self` if building the prototype
+		// fails.
+		let (body_sender, body) = hyper::Body::channel();
+		let mut request = hyper::Request::new(body);
+		*request.method_mut() = hyper::Method::from_bytes(method.as_bytes()).map_err(|_| ())?;
+		*request.uri_mut() = hyper::Uri::from_shared(From::from(uri)).map_err(|_| ())?;
+
+		let new_id = self.next_id;
+		debug_assert!(!self.requests.contains_key(&new_id));
+		match self.next_id.0.checked_add(1) {
+			Some(new_id) => self.next_id.0 = new_id,
+			None => {
+				error!("Overflow in offchain worker HTTP request ID assignment");
+				return Err(());
+			}
+		};
+		self.requests.insert(new_id, HttpApiRequest::NotDispatched(request, body_sender));
+
+		Ok(new_id)
+	}
+
+	/// Mimicks the corresponding method in the offchain API.
+	pub fn request_add_header(
+		&mut self,
+		request_id: HttpRequestId,
+		name: &str,
+		value: &str
+	) -> Result<(), ()> {
+		let request = match self.requests.get_mut(&request_id) {
+			Some(&mut HttpApiRequest::NotDispatched(ref mut rq, _)) => rq,
+			_ => return Err(())
+		};
+
+		let name = hyper::header::HeaderName::from_bytes(name.as_bytes()).map_err(|_| ())?;
+		let value = hyper::header::HeaderValue::from_str(value).map_err(|_| ())?;
+		// Note that we're always appending headers and never replacing old values.
+		// We assume here that the user knows what they're doing.
+		request.headers_mut().append(name, value);
+		Ok(())
+	}
+
+	/// Mimicks the corresponding method in the offchain API.
+	pub fn request_write_body(
+		&mut self,
+		request_id: HttpRequestId,
+		chunk: &[u8],
+		deadline: Option<Timestamp>
+	) -> Result<(), HttpError> {
+		// Extract the request from the list.
+		// Don't forget to add it back if necessary when returning.
+		let mut request = match self.requests.remove(&request_id) {
+			None => return Err(HttpError::Invalid),
+			Some(r) => r,
+		};
+
+		let mut deadline = timestamp::deadline_to_future(deadline);
+		// Closure that writes data to a sender, taking the deadline into account. Can return `Ok`
+		// (if the body has been written), or `DeadlineReached`, or `IoError`.
+		// If `IoError` is returned, don't forget to remove the request from the list.
+		let mut poll_sender = move |sender: &mut hyper::body::Sender| -> Result<(), HttpError> {
+			let mut when_ready = future::maybe_done(Compat01As03::new(
+				futures01::future::poll_fn(|| sender.poll_ready())
+			));
+			futures::executor::block_on(future::select(&mut when_ready, &mut deadline));
+			match when_ready {
+				future::MaybeDone::Done(Ok(())) => {}
+				future::MaybeDone::Done(Err(_)) => return Err(HttpError::IoError),
+				future::MaybeDone::Future(_) |
+				future::MaybeDone::Gone => {
+					debug_assert!(if let future::MaybeDone::Done(_) = deadline { true } else { false });
+					return Err(HttpError::DeadlineReached)
+				}
+			};
+
+			match sender.send_data(hyper::Chunk::from(chunk.to_owned())) {
+				Ok(()) => Ok(()),
+				Err(_chunk) => {
+					error!("HTTP sender refused data despite being ready");
+					Err(HttpError::IoError)
+				},
+			}
+		};
+
+		loop {
+			request = match request {
+				HttpApiRequest::NotDispatched(request, sender) => {
+					// If the request is not dispatched yet, dispatch it and loop again.
+					let _ = self.to_worker.unbounded_send(ApiToWorker::Dispatch {
+						id: request_id,
+						request
+					});
+					HttpApiRequest::Dispatched(Some(sender))
+				}
+
+				HttpApiRequest::Dispatched(Some(mut sender)) =>
+					if !chunk.is_empty() {
+						match poll_sender(&mut sender) {
+							Err(HttpError::IoError) => return Err(HttpError::IoError),
+							other => {
+								self.requests.insert(
+									request_id,
+									HttpApiRequest::Dispatched(Some(sender))
+								);
+								return other
+							}
+						}
+					} else {
+						// Writing an empty body is a hint that we should stop writing. Dropping
+						// the sender.
+						self.requests.insert(request_id, HttpApiRequest::Dispatched(None));
+						return Ok(())
+					}
+
+				HttpApiRequest::Response(mut response @ HttpApiRequestRp { sending_body: Some(_), .. }) =>
+					if !chunk.is_empty() {
+						match poll_sender(response.sending_body.as_mut()
+							.expect("Can only enter this match branch if Some; qed")) {
+							Err(HttpError::IoError) => return Err(HttpError::IoError),
+							other => {
+								self.requests.insert(request_id, HttpApiRequest::Response(response));
+								return other
+							}
+						}
+
+					} else {
+						// Writing an empty body is a hint that we should stop writing. Dropping
+						// the sender.
+						self.requests.insert(request_id, HttpApiRequest::Response(HttpApiRequestRp {
+							sending_body: None,
+							..response
+						}));
+						return Ok(())
+					}
+
+				HttpApiRequest::Fail(_) =>
+					// If the request has already failed, return without putting back the request
+					// in the list.
+					return Err(HttpError::IoError),
+
+				v @ HttpApiRequest::Dispatched(None) |
+				v @ HttpApiRequest::Response(HttpApiRequestRp { sending_body: None, .. }) => {
+					// We have already finished sending this body.
+					self.requests.insert(request_id, v);
+					return Err(HttpError::Invalid)
+				}
+			}
+		}
+	}
+
+	/// Mimicks the corresponding method in the offchain API.
+	pub fn response_wait(
+		&mut self,
+		ids: &[HttpRequestId],
+		deadline: Option<Timestamp>
+	) -> Vec<HttpRequestStatus> {
+		// First of all, dispatch all the non-dispatched requests and drop all senders so that the
+		// user can't write anymore data.
+		for id in ids {
+			match self.requests.get_mut(id) {
+				Some(HttpApiRequest::NotDispatched(_, _)) => {}
+				Some(HttpApiRequest::Dispatched(sending_body)) |
+				Some(HttpApiRequest::Response(HttpApiRequestRp { sending_body, .. })) => {
+					let _ = sending_body.take();
+					continue
+				}
+				_ => continue
+			};
+
+			let (request, _sender) = match self.requests.remove(id) {
+				Some(HttpApiRequest::NotDispatched(rq, s)) => (rq, s),
+				_ => unreachable!("we checked for NotDispatched above; qed")
+			};
+
+			let _ = self.to_worker.unbounded_send(ApiToWorker::Dispatch {
+				id: *id,
+				request
+			});
+
+			// We also destroy the sender in order to forbid writing more data.
+			self.requests.insert(*id, HttpApiRequest::Dispatched(None));
+		}
+
+		let mut deadline = timestamp::deadline_to_future(deadline);
+
+		loop {
+			// Within that loop, first try to see if we have all the elements for a response.
+			// This includes the situation where the deadline is reached.
+			{
+				let mut output = Vec::with_capacity(ids.len());
+				let mut must_wait_more = false;
+				for id in ids {
+					output.push(match self.requests.get_mut(id) {
+						None => HttpRequestStatus::Invalid,
+						Some(HttpApiRequest::NotDispatched(_, _)) =>
+							unreachable!("we replaced all the NotDispatched with Dispatched earlier; qed"),
+						Some(HttpApiRequest::Dispatched(_)) => {
+							must_wait_more = true;
+							HttpRequestStatus::DeadlineReached
+						},
+						Some(HttpApiRequest::Fail(_)) => HttpRequestStatus::IoError,
+						Some(HttpApiRequest::Response(HttpApiRequestRp { status_code, .. })) =>
+							HttpRequestStatus::Finished(status_code.as_u16()),
+					});
+				}
+				debug_assert_eq!(output.len(), ids.len());
+
+				// Are we ready to call `return`?
+				let is_done = if let future::MaybeDone::Done(_) = deadline {
+					true
+				} else if !must_wait_more {
+					true
+				} else {
+					false
+				};
+
+				if is_done {
+					// Requests in "fail" mode are purged before returning.
+					debug_assert_eq!(output.len(), ids.len());
+					for n in (0..ids.len()).rev() {
+						if let HttpRequestStatus::IoError = output[n] {
+							self.requests.remove(&ids[n]);
+						}
+					}
+					return output
+				}
+			}
+
+			// Grab next message from the worker. We call `continue` if deadline is reached so that
+			// we loop back and `return`.
+			let next_message = {
+				let mut next_msg = future::maybe_done(self.from_worker.next());
+				futures::executor::block_on(future::select(&mut next_msg, &mut deadline));
+				if let future::MaybeDone::Done(msg) = next_msg {
+					msg
+				} else {
+					debug_assert!(if let future::MaybeDone::Done(_) = deadline { true } else { false });
+					continue
+				}
+			};
+
+			// Update internal state based on received message.
+			match next_message {
+				Some(WorkerToApi::Response { id, status_code, headers, body }) =>
+					match self.requests.remove(&id) {
+						Some(HttpApiRequest::Dispatched(sending_body)) => {
+							self.requests.insert(id, HttpApiRequest::Response(HttpApiRequestRp {
+								sending_body,
+								status_code,
+								headers,
+								body: body.fuse(),
+								current_read_chunk: None,
+							}));
+						}
+						None => {}	// can happen if we detected an IO error when sending the body
+						_ => error!("State mismatch between the API and worker"),
+					}
+
+				Some(WorkerToApi::Fail { id, error }) =>
+					match self.requests.remove(&id) {
+						Some(HttpApiRequest::Dispatched(_)) => {
+							self.requests.insert(id, HttpApiRequest::Fail(error));
+						}
+						None => {}	// can happen if we detected an IO error when sending the body
+						_ => error!("State mismatch between the API and worker"),
+					}
+
+				None => {
+					error!("Worker has crashed");
+					return ids.iter().map(|_| HttpRequestStatus::IoError).collect()
+				}
+			}
+
+		}
+	}
+
+	/// Mimicks the corresponding method in the offchain API.
+	pub fn response_headers(
+		&mut self,
+		request_id: HttpRequestId
+	) -> Vec<(Vec<u8>, Vec<u8>)> {
+		// Do an implicit non-blocking wait on the request.
+		let _ = self.response_wait(&[request_id], Some(timestamp::now()));
+
+		let headers = match self.requests.get(&request_id) {
+			Some(HttpApiRequest::Response(HttpApiRequestRp { headers, .. })) => headers,
+			_ => return Vec::new()
+		};
+
+		headers
+			.iter()
+			.map(|(name, value)| (name.as_str().as_bytes().to_owned(), value.as_bytes().to_owned()))
+			.collect()
+	}
+
+	/// Mimicks the corresponding method in the offchain API.
+	pub fn response_read_body(
+		&mut self,
+		request_id: HttpRequestId,
+		buffer: &mut [u8],
+		deadline: Option<Timestamp>
+	) -> Result<usize, HttpError> {
+		// Do an implicit wait on the request.
+		let _ = self.response_wait(&[request_id], deadline);
+
+		// Remove the request from the list and handle situations where the request is invalid or
+		// in the wrong state.
+		let mut response = match self.requests.remove(&request_id) {
+			Some(HttpApiRequest::Response(r)) => r,
+			// Because we called `response_wait` above, we know that the deadline has been reached
+			// and we still haven't received a response.
+			Some(rq @ HttpApiRequest::Dispatched(_)) => {
+				self.requests.insert(request_id, rq);
+				return Err(HttpError::DeadlineReached)
+			},
+			// The request has failed.
+			Some(HttpApiRequest::Fail { .. }) =>
+				return Err(HttpError::IoError),
+			// Request hasn't been dispatched yet; reading the body is invalid.
+			Some(rq @ HttpApiRequest::NotDispatched(_, _)) => {
+				self.requests.insert(request_id, rq);
+				return Err(HttpError::Invalid)
+			}
+			None => return Err(HttpError::Invalid)
+		};
+
+		// Convert the deadline into a `Future` that resolves when the deadline is reached.
+		let mut deadline = timestamp::deadline_to_future(deadline);
+
+		loop {
+			// First read from `current_read_chunk`.
+			if let Some(mut current_read_chunk) = response.current_read_chunk.take() {
+				match current_read_chunk.read(buffer) {
+					Ok(0) => {}
+					Ok(n) => {
+						self.requests.insert(request_id, HttpApiRequest::Response(HttpApiRequestRp {
+							current_read_chunk: Some(current_read_chunk),
+							.. response
+						}));
+						return Ok(n)
+					},
+					Err(err) => {
+						// This code should never be reached unless there's a logic error somewhere.
+						error!("Failed to read from current read chunk: {:?}", err);
+						return Err(HttpError::IoError)
+					}
+				}
+			}
+
+			// If we reach here, that means the `current_read_chunk` is empty and needs to be
+			// filled with a new chunk from `body`. We block on either the next body or the
+			// deadline.
+			let mut next_body = future::maybe_done(response.body.next());
+			futures::executor::block_on(future::select(&mut next_body, &mut deadline));
+
+			if let future::MaybeDone::Done(next_body) = next_body {
+				match next_body {
+					Some(Ok(chunk)) => response.current_read_chunk = Some(chunk.reader()),
+					Some(Err(_)) => return Err(HttpError::IoError),
+					None => return Ok(0),  // eof
+				}
+			}
+
+			if let future::MaybeDone::Done(_) = deadline {
+				self.requests.insert(request_id, HttpApiRequest::Response(response));
+				return Err(HttpError::DeadlineReached)
+			}
+		}
+	}
+}
+
+impl fmt::Debug for HttpApi {
+	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+		f.debug_list()
+			.entries(self.requests.iter())
+			.finish()
+	}
+}
+
+impl fmt::Debug for HttpApiRequest {
+	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+		match self {
+			HttpApiRequest::NotDispatched(_, _) =>
+				f.debug_tuple("HttpApiRequest::NotDispatched").finish(),
+			HttpApiRequest::Dispatched(_) =>
+				f.debug_tuple("HttpApiRequest::Dispatched").finish(),
+			HttpApiRequest::Response(HttpApiRequestRp { status_code, headers, .. }) =>
+				f.debug_tuple("HttpApiRequest::Response").field(status_code).field(headers).finish(),
+			HttpApiRequest::Fail(err) =>
+				f.debug_tuple("HttpApiRequest::Fail").field(err).finish(),
+		}
+	}
+}
+
+/// Message send from the API to the worker.
+enum ApiToWorker {
+	/// Dispatches a new HTTP request.
+	Dispatch {
+		/// ID to send back when the response comes back.
+		id: HttpRequestId,
+		/// Request to start executing.
+		request: hyper::Request<hyper::Body>,
+	}
+}
+
+/// Message send from the API to the worker.
+enum WorkerToApi {
+	/// A request has succeeded.
+	Response {
+		/// The ID that was passed to the worker.
+		id: HttpRequestId,
+		/// Status code of the response.
+		status_code: hyper::StatusCode,
+		/// Headers of the response.
+		headers: hyper::HeaderMap,
+		/// Body of the response, as a channel of `Chunk` objects.
+		/// We send the body back through a channel instead of returning the hyper `Body` object
+		/// because we don't want the `HttpApi` to have to drive the reading.
+		/// Instead, reading an item from the channel will notify the worker task, which will push
+		/// the next item.
+		/// Can also be used to send an error, in case an error happend on the HTTP socket. After
+		/// an error is sent, the channel will close.
+		body: mpsc::Receiver<Result<hyper::Chunk, hyper::Error>>,
+	},
+	/// A request has failed because of an error. The request is then no longer valid.
+	Fail {
+		/// The ID that was passed to the worker.
+		id: HttpRequestId,
+		/// Error that happened.
+		error: hyper::Error,
+	},
+}
+
+/// Wraps around a `hyper::Client` with either TLS enabled or disabled.
+enum HyperClient {
+	/// Everything is ok and HTTPS is available.
+	Https(hyper::Client<hyper_tls::HttpsConnector<hyper::client::HttpConnector>, hyper::Body>),
+	/// We failed to initialize HTTPS and therefore only allow HTTP.
+	Http(hyper::Client<hyper::client::HttpConnector, hyper::Body>),
+}
+
+impl HyperClient {
+	/// Creates new hyper client.
+	///
+	/// By default we will try to initialize the `HttpsConnector`,
+	/// If that's not possible we'll fall back to `HttpConnector`.
+	pub fn new() -> Self {
+		match hyper_tls::HttpsConnector::new(1) {
+			Ok(tls) => HyperClient::Https(hyper::Client::builder().build(tls)),
+			Err(e) => {
+				warn!("Unable to initialize TLS client. Falling back to HTTP-only: {:?}", e);
+				HyperClient::Http(hyper::Client::new())
+			},
+		}
+	}
+}
+
+/// Must be continuously polled for the [`HttpApi`] to properly work.
+pub struct HttpWorker {
+	/// Used to sends messages to the `HttpApi`.
+	to_api: mpsc::UnboundedSender<WorkerToApi>,
+	/// Used to receive messages from the `HttpApi`.
+	from_api: mpsc::UnboundedReceiver<ApiToWorker>,
+	/// The engine that runs HTTP requests.
+	http_client: HyperClient,
+	/// HTTP requests that are being worked on by the engine.
+	requests: Vec<(HttpRequestId, HttpWorkerRequest)>,
+}
+
+/// HTTP request being processed by the worker.
+enum HttpWorkerRequest {
+	/// Request has been dispatched and is waiting for a response from the Internet.
+	Dispatched(Compat01As03<hyper::client::ResponseFuture>),
+	/// Progressively reading the body of the response and sending it to the channel.
+	ReadBody {
+		/// Body to read `Chunk`s from. Only used if the channel is ready to accept data.
+		body: Compat01As03<hyper::Body>,
+		/// Channel to the [`HttpApi`] where we send the chunks to.
+		tx: mpsc::Sender<Result<hyper::Chunk, hyper::Error>>,
+	},
+}
+
+impl Future for HttpWorker {
+	type Output = ();
+
+	fn poll(mut self: Pin<&mut Self>, cx: &mut Context) -> Poll<Self::Output> {
+		// Reminder: this is continuously run in the background.
+
+		// We use a `me` variable because the compiler isn't smart enough to allow borrowing
+		// multiple fields at once through a `Deref`.
+		let me = &mut *self;
+
+		// We remove each element from `requests` one by one and add them back only if necessary.
+		for n in (0..me.requests.len()).rev() {
+			let (id, request) = me.requests.swap_remove(n);
+			match request {
+				HttpWorkerRequest::Dispatched(mut future) => {
+					// Check for an HTTP response from the Internet.
+					let mut response = match Future::poll(Pin::new(&mut future), cx) {
+						Poll::Pending => {
+							me.requests.push((id, HttpWorkerRequest::Dispatched(future)));
+							continue
+						},
+						Poll::Ready(Ok(response)) => response,
+						Poll::Ready(Err(err)) => {
+							let _ = me.to_api.unbounded_send(WorkerToApi::Fail {
+								id,
+								error: err,
+							});
+							continue;		// don't insert the request back
+						}
+					};
+
+					// We received a response! Decompose it into its parts.
+					let status_code = response.status();
+					let headers = mem::replace(response.headers_mut(), hyper::HeaderMap::new());
+					let body = Compat01As03::new(response.into_body());
+
+					let (body_tx, body_rx) = mpsc::channel(3);
+					let _ = me.to_api.unbounded_send(WorkerToApi::Response {
+						id,
+						status_code,
+						headers,
+						body: body_rx,
+					});
+
+					me.requests.push((id, HttpWorkerRequest::ReadBody { body, tx: body_tx }));
+					cx.waker().wake_by_ref();	// reschedule in order to poll the new future
+					continue
+				}
+
+				HttpWorkerRequest::ReadBody { mut body, mut tx } => {
+					// Before reading from the HTTP response, check that `tx` is ready to accept
+					// a new chunk.
+					match tx.poll_ready(cx) {
+						Poll::Ready(Ok(())) => {}
+						Poll::Ready(Err(_)) => continue,  // don't insert the request back
+						Poll::Pending => {
+							me.requests.push((id, HttpWorkerRequest::ReadBody { body, tx }));
+							continue
+						}
+					}
+
+					// `tx` is ready. Read a chunk from the socket and send it to the channel.
+					match Stream::poll_next(Pin::new(&mut body), cx) {
+						Poll::Ready(Some(Ok(chunk))) => {
+							let _ = tx.start_send(Ok(chunk));
+							me.requests.push((id, HttpWorkerRequest::ReadBody { body, tx }));
+							cx.waker().wake_by_ref();	// reschedule in order to continue reading
+						}
+						Poll::Ready(Some(Err(err))) => {
+							let _ = tx.start_send(Err(err));
+							// don't insert the request back
+						},
+						Poll::Ready(None) => {}		// EOF; don't insert the request back
+						Poll::Pending => {
+							me.requests.push((id, HttpWorkerRequest::ReadBody { body, tx }));
+						},
+					}
+				}
+			}
+		}
+
+		// Check for messages coming from the [`HttpApi`].
+		match Stream::poll_next(Pin::new(&mut me.from_api), cx) {
+			Poll::Pending => {},
+			Poll::Ready(None) => return Poll::Ready(()),	// stops the worker
+			Poll::Ready(Some(ApiToWorker::Dispatch { id, request })) => {
+				let future = Compat01As03::new(match me.http_client {
+					HyperClient::Http(ref mut c) => c.request(request),
+					HyperClient::Https(ref mut c) => c.request(request),
+				});
+				debug_assert!(me.requests.iter().all(|(i, _)| *i != id));
+				me.requests.push((id, HttpWorkerRequest::Dispatched(future)));
+				cx.waker().wake_by_ref();	// reschedule the task to poll the request
+			}
+		}
+
+		Poll::Pending
+	}
+}
+
+impl fmt::Debug for HttpWorker {
+	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+		f.debug_list()
+			.entries(self.requests.iter())
+			.finish()
+	}
+}
+
+impl fmt::Debug for HttpWorkerRequest {
+	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+		match self {
+			HttpWorkerRequest::Dispatched(_) =>
+				f.debug_tuple("HttpWorkerRequest::Dispatched").finish(),
+			HttpWorkerRequest::ReadBody { .. } =>
+				f.debug_tuple("HttpWorkerRequest::Response").finish(),
+		}
+	}
+}
+
+#[cfg(test)]
+mod tests {
+	use crate::api::timestamp;
+	use super::http;
+	use futures::prelude::*;
+	use futures01::Future as _;
+	use primitives::offchain::{HttpError, HttpRequestId, HttpRequestStatus, Duration};
+
+	// Returns an `HttpApi` whose worker is ran in the background, and a `SocketAddr` to an HTTP
+	// server that runs in the background as well.
+	macro_rules! build_api_server {
+		() => {{
+			let (api, worker) = http();
+			// Note: we have to use tokio because hyper still uses old futures.
+			std::thread::spawn(move || {
+				tokio::run(futures::compat::Compat::new(worker.map(|()| Ok::<(), ()>(()))))
+			});
+			let (addr_tx, addr_rx) = std::sync::mpsc::channel();
+			std::thread::spawn(move || {
+				let server = hyper::Server::bind(&"127.0.0.1:0".parse().unwrap())
+					.serve(|| {
+						hyper::service::service_fn_ok(move |_: hyper::Request<hyper::Body>| {
+							hyper::Response::new(hyper::Body::from("Hello World!"))
+						})
+					});
+				let _ = addr_tx.send(server.local_addr());
+				hyper::rt::run(server.map_err(|e| panic!("{:?}", e)));
+			});
+			(api, addr_rx.recv().unwrap())
+		}};
+	}
+
+	#[test]
+	fn basic_localhost() {
+		let deadline = timestamp::now().add(Duration::from_millis(10_000));
+
+		// Performs an HTTP query to a background HTTP server.
+
+		let (mut api, addr) = build_api_server!();
+
+		let id = api.request_start("GET", &format!("http://{}", addr)).unwrap();
+		api.request_write_body(id, &[], Some(deadline)).unwrap();
+
+		match api.response_wait(&[id], Some(deadline))[0] {
+			HttpRequestStatus::Finished(200) => {},
+			v => panic!("Connecting to localhost failed: {:?}", v)
+		}
+
+		let headers = api.response_headers(id);
+		assert!(headers.iter().any(|(h, _)| h.eq_ignore_ascii_case(b"Date")));
+
+		let mut buf = vec![0; 2048];
+		let n = api.response_read_body(id, &mut buf, Some(deadline)).unwrap();
+		assert_eq!(&buf[..n], b"Hello World!");
+	}
+
+	#[test]
+	fn request_start_invalid_call() {
+		let (mut api, addr) = build_api_server!();
+
+		match api.request_start("\0", &format!("http://{}", addr)) {
+			Err(()) => {}
+			Ok(_) => panic!()
+		};
+
+		match api.request_start("GET", "http://\0localhost") {
+			Err(()) => {}
+			Ok(_) => panic!()
+		};
+	}
+
+	#[test]
+	fn request_add_header_invalid_call() {
+		let (mut api, addr) = build_api_server!();
+
+		match api.request_add_header(HttpRequestId(0xdead), "Foo", "bar") {
+			Err(()) => {}
+			Ok(_) => panic!()
+		};
+
+		let id = api.request_start("GET", &format!("http://{}", addr)).unwrap();
+		match api.request_add_header(id, "\0", "bar") {
+			Err(()) => {}
+			Ok(_) => panic!()
+		};
+
+		let id = api.request_start("GET", &format!("http://{}", addr)).unwrap();
+		match api.request_add_header(id, "Foo", "\0") {
+			Err(()) => {}
+			Ok(_) => panic!()
+		};
+
+		let id = api.request_start("GET", &format!("http://{}", addr)).unwrap();
+		api.request_add_header(id, "Foo", "Bar").unwrap();
+		api.request_write_body(id, &[1, 2, 3, 4], None).unwrap();
+		match api.request_add_header(id, "Foo2", "Bar") {
+			Err(()) => {}
+			Ok(_) => panic!()
+		};
+
+		let id = api.request_start("GET", &format!("http://{}", addr)).unwrap();
+		api.response_headers(id);
+		match api.request_add_header(id, "Foo2", "Bar") {
+			Err(()) => {}
+			Ok(_) => panic!()
+		};
+
+		let id = api.request_start("GET", &format!("http://{}", addr)).unwrap();
+		api.response_read_body(id, &mut [], None).unwrap();
+		match api.request_add_header(id, "Foo2", "Bar") {
+			Err(()) => {}
+			Ok(_) => panic!()
+		};
+	}
+
+	#[test]
+	fn request_write_body_invalid_call() {
+		let (mut api, addr) = build_api_server!();
+
+		match api.request_write_body(HttpRequestId(0xdead), &[1, 2, 3], None) {
+			Err(HttpError::Invalid) => {}
+			_ => panic!()
+		};
+
+		match api.request_write_body(HttpRequestId(0xdead), &[], None) {
+			Err(HttpError::Invalid) => {}
+			_ => panic!()
+		};
+
+		let id = api.request_start("GET", &format!("http://{}", addr)).unwrap();
+		api.request_write_body(id, &[1, 2, 3, 4], None).unwrap();
+		api.request_write_body(id, &[1, 2, 3, 4], None).unwrap();
+		api.request_write_body(id, &[], None).unwrap();
+		match api.request_write_body(id, &[], None) {
+			Err(HttpError::Invalid) => {}
+			_ => panic!()
+		};
+
+		let id = api.request_start("GET", &format!("http://{}", addr)).unwrap();
+		api.request_write_body(id, &[1, 2, 3, 4], None).unwrap();
+		api.request_write_body(id, &[1, 2, 3, 4], None).unwrap();
+		api.request_write_body(id, &[], None).unwrap();
+		match api.request_write_body(id, &[1, 2, 3, 4], None) {
+			Err(HttpError::Invalid) => {}
+			_ => panic!()
+		};
+
+		let id = api.request_start("GET", &format!("http://{}", addr)).unwrap();
+		api.request_write_body(id, &[1, 2, 3, 4], None).unwrap();
+		api.response_wait(&[id], None);
+		match api.request_write_body(id, &[], None) {
+			Err(HttpError::Invalid) => {}
+			_ => panic!()
+		};
+
+		let id = api.request_start("GET", &format!("http://{}", addr)).unwrap();
+		api.request_write_body(id, &[1, 2, 3, 4], None).unwrap();
+		api.response_wait(&[id], None);
+		match api.request_write_body(id, &[1, 2, 3, 4], None) {
+			Err(HttpError::Invalid) => {}
+			_ => panic!()
+		};
+
+		let id = api.request_start("GET", &format!("http://{}", addr)).unwrap();
+		api.response_headers(id);
+		match api.request_write_body(id, &[1, 2, 3, 4], None) {
+			Err(HttpError::Invalid) => {}
+			_ => panic!()
+		};
+
+		let id = api.request_start("GET", &format!("http://{}", addr)).unwrap();
+		api.response_headers(id);
+		match api.request_write_body(id, &[], None) {
+			Err(HttpError::Invalid) => {}
+			_ => panic!()
+		};
+
+		let id = api.request_start("GET", &format!("http://{}", addr)).unwrap();
+		api.response_read_body(id, &mut [], None).unwrap();
+		match api.request_write_body(id, &[1, 2, 3, 4], None) {
+			Err(HttpError::Invalid) => {}
+			_ => panic!()
+		};
+
+		let id = api.request_start("GET", &format!("http://{}", addr)).unwrap();
+		api.response_read_body(id, &mut [], None).unwrap();
+		match api.request_write_body(id, &[], None) {
+			Err(HttpError::Invalid) => {}
+			_ => panic!()
+		};
+	}
+
+	#[test]
+	fn response_headers_invalid_call() {
+		let (mut api, addr) = build_api_server!();
+		assert!(api.response_headers(HttpRequestId(0xdead)).is_empty());
+
+		let id = api.request_start("GET", &format!("http://{}", addr)).unwrap();
+		assert!(api.response_headers(id).is_empty());
+
+		let id = api.request_start("GET", &format!("http://{}", addr)).unwrap();
+		api.request_write_body(id, &[], None).unwrap();
+		while api.response_headers(id).is_empty() {
+			std::thread::sleep(std::time::Duration::from_millis(100));
+		}
+
+		let id = api.request_start("GET", &format!("http://{}", addr)).unwrap();
+		api.response_wait(&[id], None);
+		assert!(!api.response_headers(id).is_empty());
+
+		let id = api.request_start("GET", &format!("http://{}", addr)).unwrap();
+		let mut buf = [0; 128];
+		while api.response_read_body(id, &mut buf, None).unwrap() != 0 {}
+		assert!(api.response_headers(id).is_empty());
+	}
+
+	#[test]
+	fn response_header_invalid_call() {
+		let (mut api, addr) = build_api_server!();
+
+		let id = api.request_start("GET", &format!("http://{}", addr)).unwrap();
+		assert!(api.response_headers(id).is_empty());
+
+		let id = api.request_start("GET", &format!("http://{}", addr)).unwrap();
+		api.request_add_header(id, "Foo", "Bar").unwrap();
+		assert!(api.response_headers(id).is_empty());
+
+		let id = api.request_start("GET", &format!("http://{}", addr)).unwrap();
+		api.request_add_header(id, "Foo", "Bar").unwrap();
+		api.request_write_body(id, &[], None).unwrap();
+		// Note: this test actually sends out the request, and is supposed to test a situation
+		// where we haven't received any response yet. This test can theoretically fail if the
+		// HTTP response comes back faster than the kernel schedules our thread, but that is highly
+		// unlikely.
+		assert!(api.response_headers(id).is_empty());
+	}
+
+	#[test]
+	fn response_read_body_invalid_call() {
+		let (mut api, addr) = build_api_server!();
+		let mut buf = [0; 512];
+
+		match api.response_read_body(HttpRequestId(0xdead), &mut buf, None) {
+			Err(HttpError::Invalid) => {}
+			_ => panic!()
+		}
+
+		let id = api.request_start("GET", &format!("http://{}", addr)).unwrap();
+		while api.response_read_body(id, &mut buf, None).unwrap() != 0 {}
+		match api.response_read_body(id, &mut buf, None) {
+			Err(HttpError::Invalid) => {}
+			_ => panic!()
+		}
+	}
+
+	#[test]
+	fn fuzzing() {
+		// Uses the API in random ways to try to trigger panicks.
+		// Doesn't test some paths, such as waiting for multiple requests. Also doesn't test what
+		// happens if the server force-closes our socket.
+
+		let (mut api, addr) = build_api_server!();
+
+		for _ in 0..50 {
+			let id = api.request_start("GET", &format!("http://{}", addr)).unwrap();
+
+			for _ in 0..250 {
+				match rand::random::<u8>() % 6 {
+					0 => { let _ = api.request_add_header(id, "Foo", "Bar"); }
+					1 => { let _ = api.request_write_body(id, &[1, 2, 3, 4], None); }
+					2 => { let _ = api.request_write_body(id, &[], None); }
+					3 => { let _ = api.response_wait(&[id], None); }
+					4 => { let _ = api.response_headers(id); }
+					5 => {
+						let mut buf = [0; 512];
+						let _ = api.response_read_body(id, &mut buf, None);
+					}
+					6 ..= 255 => unreachable!()
+				}
+			}
+		}
+	}
+}
diff --git a/core/offchain/src/api/timestamp.rs b/core/offchain/src/api/timestamp.rs
new file mode 100644
index 0000000000000..445c7f3878474
--- /dev/null
+++ b/core/offchain/src/api/timestamp.rs
@@ -0,0 +1,62 @@
+// Copyright 2019 Parity Technologies (UK) Ltd.
+// This file is part of Substrate.
+
+// Substrate is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Substrate is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Substrate.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Helper methods dedicated to timestamps.
+
+use primitives::offchain::Timestamp;
+use std::convert::TryInto;
+use std::time::{SystemTime, Duration};
+
+/// Returns the current time as a `Timestamp`.
+pub fn now() -> Timestamp {
+	let now = SystemTime::now();
+	let epoch_duration = now.duration_since(SystemTime::UNIX_EPOCH);
+	match epoch_duration {
+		Err(_) => {
+			// Current time is earlier than UNIX_EPOCH.
+			Timestamp::from_unix_millis(0)
+		},
+		Ok(d) => {
+			let duration = d.as_millis();
+			// Assuming overflow won't happen for a few hundred years.
+			Timestamp::from_unix_millis(duration.try_into()
+				.expect("epoch milliseconds won't overflow u64 for hundreds of years; qed"))
+		}
+	}
+}
+
+/// Returns how a `Timestamp` compares to "now".
+///
+/// In other words, returns `timestamp - now()`.
+pub fn timestamp_from_now(timestamp: Timestamp) -> Duration {
+	Duration::from_millis(timestamp.diff(&now()).millis())
+}
+
+/// Converts the deadline into a `Future` that resolves when the deadline is reached.
+///
+/// If `None`, returns a never-ending `Future`.
+pub fn deadline_to_future(
+	deadline: Option<Timestamp>,
+) -> futures::future::MaybeDone<impl futures::Future> {
+	use futures::future;
+
+	future::maybe_done(match deadline {
+		Some(deadline) => future::Either::Left(
+			futures_timer::Delay::new(timestamp_from_now(deadline))
+		),
+		None => future::Either::Right(future::pending())
+	})
+}
diff --git a/core/offchain/src/lib.rs b/core/offchain/src/lib.rs
index b38b202c62e08..9b785ec8bada1 100644
--- a/core/offchain/src/lib.rs
+++ b/core/offchain/src/lib.rs
@@ -43,7 +43,7 @@ use client::runtime_api::ApiExt;
 use futures::future::Future;
 use log::{debug, warn};
 use network::NetworkStateInfo;
-use primitives::ExecutionContext;
+use primitives::{offchain, ExecutionContext};
 use sr_primitives::{generic::BlockId, traits::{self, ProvideRuntimeApi}};
 use transaction_pool::txpool::{Pool, ChainApi};
 
@@ -122,7 +122,7 @@ impl<Client, Storage, Block> OffchainWorkers<
 				debug!("Running offchain workers at {:?}", at);
 				let run = runtime.offchain_worker_with_context(
 					&at,
-					ExecutionContext::OffchainWorker(api),
+					ExecutionContext::OffchainCall(Some((api, offchain::Capabilities::all()))),
 					number,
 				);
 				if let Err(e) =	run {
diff --git a/core/offchain/src/testing.rs b/core/offchain/src/testing.rs
index cdf2878c13e3f..8724ca7546604 100644
--- a/core/offchain/src/testing.rs
+++ b/core/offchain/src/testing.rs
@@ -248,7 +248,7 @@ impl offchain::Externalities for TestOffchainExt {
 
 		ids.iter().map(|id| match state.requests.get(id) {
 			Some(req) if req.response.is_empty() => RequestStatus::DeadlineReached,
-			None => RequestStatus::Unknown,
+			None => RequestStatus::Invalid,
 			_ => RequestStatus::Finished(200),
 		}).collect()
 	}
diff --git a/core/primitives/Cargo.toml b/core/primitives/Cargo.toml
index b9bb141ad7616..f05907e3f205e 100644
--- a/core/primitives/Cargo.toml
+++ b/core/primitives/Cargo.toml
@@ -13,6 +13,7 @@ twox-hash = { version = "1.2.0", optional = true }
 byteorder = { version = "1.3.1", default-features = false }
 primitive-types = { version = "0.5.0", default-features = false, features = ["codec"] }
 impl-serde = { version = "0.1", optional = true }
+log = { version = "0.4", optional = true }
 wasmi = { version = "0.5.0", optional = true }
 hash-db = { version = "0.15.2", default-features = false }
 hash256-std-hasher = { version = "0.15.2", default-features = false }
@@ -48,6 +49,7 @@ bench = false
 [features]
 default = ["std"]
 std = [
+	"log",
 	"wasmi",
 	"lazy_static",
     "parking_lot",
diff --git a/core/primitives/src/lib.rs b/core/primitives/src/lib.rs
index 21e7c878082ad..5c918e4964e37 100644
--- a/core/primitives/src/lib.rs
+++ b/core/primitives/src/lib.rs
@@ -88,19 +88,23 @@ pub enum ExecutionContext {
 	Syncing,
 	/// Context used for block construction.
 	BlockConstruction,
-	/// Offchain worker context.
-	OffchainWorker(Box<dyn offchain::Externalities>),
-	/// Context used for other calls.
-	Other,
+	/// Context used for offchain calls.
+	///
+	/// This allows passing offchain extension and customizing available capabilities.
+	OffchainCall(Option<(Box<dyn offchain::Externalities>, offchain::Capabilities)>),
 }
 
 impl ExecutionContext {
-	/// Returns if the keystore should be enabled for the current context.
-	pub fn enable_keystore(&self) -> bool {
+	/// Returns the capabilities of particular context.
+	pub fn capabilities(&self) -> offchain::Capabilities {
 		use ExecutionContext::*;
+
 		match self {
-			Importing | Syncing | BlockConstruction => false,
-			OffchainWorker(_) | Other => true,
+			Importing | Syncing | BlockConstruction =>
+				offchain::Capabilities::none(),
+			// Enable keystore by default for offchain calls. CC @bkchr
+			OffchainCall(None) => [offchain::Capability::Keystore][..].into(),
+			OffchainCall(Some((_, capabilities))) => *capabilities,
 		}
 	}
 }
diff --git a/core/primitives/src/offchain.rs b/core/primitives/src/offchain.rs
index 52dbf5fbee356..6f024c5c02414 100644
--- a/core/primitives/src/offchain.rs
+++ b/core/primitives/src/offchain.rs
@@ -61,7 +61,7 @@ impl From<StorageKind> for u32 {
 
 /// Opaque type for offchain http requests.
 #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
-#[cfg_attr(feature = "std", derive(Debug))]
+#[cfg_attr(feature = "std", derive(Debug, Hash))]
 pub struct HttpRequestId(pub u16);
 
 impl From<HttpRequestId> for u32 {
@@ -79,6 +79,8 @@ pub enum HttpError {
 	DeadlineReached = 1,
 	/// There was an IO Error while processing the request.
 	IoError = 2,
+	/// The ID of the request is invalid in this context.
+	Invalid = 3,
 }
 
 impl TryFrom<u32> for HttpError {
@@ -88,6 +90,7 @@ impl TryFrom<u32> for HttpError {
 		match error {
 			e if e == HttpError::DeadlineReached as u8 as u32 => Ok(HttpError::DeadlineReached),
 			e if e == HttpError::IoError as u8 as u32 => Ok(HttpError::IoError),
+			e if e == HttpError::Invalid as u8 as u32 => Ok(HttpError::Invalid),
 			_ => Err(())
 		}
 	}
@@ -105,18 +108,17 @@ impl From<HttpError> for u32 {
 pub enum HttpRequestStatus {
 	/// Deadline was reached while we waited for this request to finish.
 	///
-	/// Note the deadline is controlled by the calling part, it not necessarily means
-	/// that the request has timed out.
+	/// Note the deadline is controlled by the calling part, it not necessarily
+	/// means that the request has timed out.
 	DeadlineReached,
-	/// Request timed out.
-	///
-	/// This means that the request couldn't be completed by the host environment
-	/// within a reasonable time (according to the host), has now been terminated
-	/// and is considered finished.
-	/// To retry the request you need to construct it again.
-	Timeout,
-	/// Request status of this ID is not known.
-	Unknown,
+	/// An error has occured during the request, for example a timeout or the
+	/// remote has closed our socket.
+	///
+	/// The request is now considered destroyed. To retry the request you need
+	/// to construct it again.
+	IoError,
+	/// The passed ID is invalid in this context.
+	Invalid,
 	/// The request has finished with given status code.
 	Finished(u16),
 }
@@ -124,9 +126,9 @@ pub enum HttpRequestStatus {
 impl From<HttpRequestStatus> for u32 {
 	fn from(status: HttpRequestStatus) -> Self {
 		match status {
-			HttpRequestStatus::Unknown => 0,
+			HttpRequestStatus::Invalid => 0,
 			HttpRequestStatus::DeadlineReached => 10,
-			HttpRequestStatus::Timeout => 20,
+			HttpRequestStatus::IoError => 20,
 			HttpRequestStatus::Finished(code) => u32::from(code),
 		}
 	}
@@ -137,9 +139,9 @@ impl TryFrom<u32> for HttpRequestStatus {
 
 	fn try_from(status: u32) -> Result<Self, Self::Error> {
 		match status {
-			0 => Ok(HttpRequestStatus::Unknown),
+			0 => Ok(HttpRequestStatus::Invalid),
 			10 => Ok(HttpRequestStatus::DeadlineReached),
-			20 => Ok(HttpRequestStatus::Timeout),
+			20 => Ok(HttpRequestStatus::IoError),
 			100..=999 => u16::try_from(status).map(HttpRequestStatus::Finished).map_err(|_| ()),
 			_ => Err(()),
 		}
@@ -230,6 +232,70 @@ impl Timestamp {
 	}
 }
 
+/// Execution context extra capabilities.
+#[derive(Debug, PartialEq, Eq, Clone, Copy)]
+#[repr(u8)]
+pub enum Capability {
+	/// Access to transaction pool.
+	TransactionPool = 1,
+	/// External http calls.
+	Http = 2,
+	/// Keystore access.
+	Keystore = 4,
+	/// Randomness source.
+	Randomness = 8,
+	/// Access to opaque network state.
+	NetworkState = 16,
+	/// Access to offchain worker DB (read only).
+	OffchainWorkerDbRead = 32,
+	/// Access to offchain worker DB (writes).
+	OffchainWorkerDbWrite = 64,
+}
+
+/// A set of capabilities
+#[derive(Debug, PartialEq, Eq, Clone, Copy)]
+pub struct Capabilities(u8);
+
+impl Capabilities {
+	/// Return an object representing an empty set of capabilities.
+	pub fn none() -> Self {
+		Self(0)
+	}
+
+	/// Return an object representing all capabilities enabled.
+	pub fn all() -> Self {
+		Self(u8::max_value())
+	}
+
+	/// Return capabilities for rich offchain calls.
+	///
+	/// Those calls should be allowed to sign and submit transactions
+	/// and access offchain workers database (but read only!).
+	pub fn rich_offchain_call() -> Self {
+		[
+			Capability::TransactionPool,
+			Capability::Keystore,
+			Capability::OffchainWorkerDbRead,
+		][..].into()
+	}
+
+	/// Check if particular capability is enabled.
+	pub fn has(&self, capability: Capability) -> bool {
+		self.0 & capability as u8 != 0
+	}
+
+	/// Check if this capability object represents all capabilities.
+	pub fn has_all(&self) -> bool {
+		self == &Capabilities::all()
+	}
+}
+
+impl<'a> From<&'a [Capability]> for Capabilities {
+	fn from(list: &'a [Capability]) -> Self {
+		Capabilities(list.iter().fold(0_u8, |a, b| a | *b as u8))
+	}
+}
+
 /// An extended externalities for offchain workers.
 pub trait Externalities {
 	/// Returns if the local node is a potential validator.
@@ -291,6 +357,11 @@ pub trait Externalities {
 	///
 	/// Meta is a future-reserved field containing additional, parity-scale-codec encoded parameters.
 	/// Returns the id of newly started request.
+	///
+	/// Returns an error if:
+	/// - No new request identifier could be allocated.
+	/// - The method or URI contain invalid characters.
+	///
 	fn http_request_start(
 		&mut self,
 		method: &str,
@@ -299,6 +370,18 @@ pub trait Externalities {
 	) -> Result<HttpRequestId, ()>;
 
 	/// Append header to the request.
+	///
+	/// Calling this function multiple times with the same header name continues appending new
+	/// headers. In other words, headers are never replaced.
+	///
+	/// Returns an error if:
+	/// - The request identifier is invalid.
+	/// - You have called `http_request_write_body` on that request.
+	/// - The name or value contain invalid characters.
+	///
+	/// An error doesn't poison the request, and you can continue as if the call had never been
+	/// made.
+	///
 	fn http_request_add_header(
 		&mut self,
 		request_id: HttpRequestId,
@@ -308,10 +391,19 @@ pub trait Externalities {
 
 	/// Write a chunk of request body.
 	///
-	/// Writing an empty chunks finalises the request.
+	/// Calling this function with a non-empty slice may or may not start the
+	/// HTTP request. Calling this function with an empty chunks finalizes the
+	/// request and always starts it. It is no longer valid to write more data
+	/// afterwards.
 	/// Passing `None` as deadline blocks forever.
 	///
-	/// Returns an error in case deadline is reached or the chunk couldn't be written.
+	/// Returns an error if:
+	/// - The request identifier is invalid.
+	/// - `http_response_wait` has already been called on this request.
+	/// - The deadline is reached.
+	/// - An I/O error has happened, for example the remote has closed our
+	///   request. The request is then considered invalid.
+	///
 	fn http_request_write_body(
 		&mut self,
 		request_id: HttpRequestId,
@@ -325,6 +417,9 @@ pub trait Externalities {
 	/// Note that if deadline is not provided the method will block indefinitely,
 	/// otherwise unready responses will produce `DeadlineReached` status.
 	///
+	/// If a response returns an `IoError`, it is then considered destroyed.
+	/// Its id is then invalid.
+	///
 	/// Passing `None` as deadline blocks forever.
 	fn http_response_wait(
 		&mut self,
@@ -335,6 +430,12 @@ pub trait Externalities {
 	/// Read all response headers.
 	///
 	/// Returns a vector of pairs `(HeaderKey, HeaderValue)`.
+	///
+	/// Dispatches the request if it hasn't been done yet. It is no longer
+	/// valid to modify the headers or write data to the request.
+	///
+	/// Returns an empty list if the identifier is unknown/invalid, hasn't
+	/// received a response, or has finished.
 	fn http_response_headers(
 		&mut self,
 		request_id: HttpRequestId
@@ -342,9 +443,23 @@ pub trait Externalities {
 
 	/// Read a chunk of body response to given buffer.
 	///
+	/// Dispatches the request if it hasn't been done yet. It is no longer
+	/// valid to modify the headers or write data to the request.
+	///
 	/// Returns the number of bytes written or an error in case a deadline
 	/// is reached or server closed the connection.
 	/// Passing `None` as a deadline blocks forever.
+	///
+	/// If `Ok(0)` or `Err(IoError)` is returned, the request is considered
+	/// destroyed. Doing another read or getting the response's headers, for
+	/// example, is then invalid.
+	///
+	/// Returns an error if:
+	/// - The request identifier is invalid.
+	/// - The deadline is reached.
+	/// - An I/O error has happened, for example the remote has closed our
+	///   request. The request is then considered invalid.
+	///
 	fn http_response_read_body(
 		&mut self,
 		request_id: HttpRequestId,
@@ -430,6 +545,123 @@ impl<T: Externalities + ?Sized> Externalities for Box<T> {
 		(&mut **self).http_response_read_body(request_id, buffer, deadline)
 	}
 }
+/// An `OffchainExternalities` implementation with limited capabilities.
+pub struct LimitedExternalities<T> {
+	capabilities: Capabilities,
+	externalities: T,
+}
+
+impl<T> LimitedExternalities<T> {
+	/// Create new externalities limited to given `capabilities`.
+	pub fn new(capabilities: Capabilities, externalities: T) -> Self {
+		Self {
+			capabilities,
+			externalities,
+		}
+	}
+
+	/// Check if given capability is allowed.
+	///
+	/// Panics in case it is not.
+	fn check(&self, capability: Capability, name: &'static str) {
+		if !self.capabilities.has(capability) {
+			panic!("Accessing a forbidden API: {}. No: {:?} capability.", name, capability);
+		}
+	}
+}
+
+impl<T: Externalities> Externalities for LimitedExternalities<T> {
+	fn is_validator(&self) -> bool {
+		self.check(Capability::Keystore, "is_validator");
+		self.externalities.is_validator()
+	}
+
+	fn submit_transaction(&mut self, ex: Vec<u8>) -> Result<(), ()> {
+		self.check(Capability::TransactionPool, "submit_transaction");
+		self.externalities.submit_transaction(ex)
+	}
+
+	fn network_state(&self) -> Result<OpaqueNetworkState, ()> {
+		self.check(Capability::NetworkState, "network_state");
+		self.externalities.network_state()
+	}
+
+	fn timestamp(&mut self) -> Timestamp {
+		self.check(Capability::Http, "timestamp");
+		self.externalities.timestamp()
+	}
+
+	fn sleep_until(&mut self, deadline: Timestamp) {
+		self.check(Capability::Http, "sleep_until");
+		self.externalities.sleep_until(deadline)
+	}
+
+	fn random_seed(&mut self) -> [u8; 32] {
+		self.check(Capability::Randomness, "random_seed");
+		self.externalities.random_seed()
+	}
+
+	fn local_storage_set(&mut self, kind: StorageKind, key: &[u8], value: &[u8]) {
+		self.check(Capability::OffchainWorkerDbWrite, "local_storage_set");
+		self.externalities.local_storage_set(kind, key, value)
+	}
+
+	fn local_storage_compare_and_set(
+		&mut self,
+		kind: StorageKind,
+		key: &[u8],
+		old_value: Option<&[u8]>,
+		new_value: &[u8],
+	) -> bool {
+		self.check(Capability::OffchainWorkerDbWrite, "local_storage_compare_and_set");
+		self.externalities.local_storage_compare_and_set(kind, key, old_value, new_value)
+	}
+
+	fn local_storage_get(&mut self, kind: StorageKind, key: &[u8]) -> Option<Vec<u8>> {
+		self.check(Capability::OffchainWorkerDbRead, "local_storage_get");
+		self.externalities.local_storage_get(kind, key)
+	}
+
+	fn http_request_start(&mut self, method: &str, uri: &str, meta: &[u8]) -> Result<HttpRequestId, ()> {
+		self.check(Capability::Http, "http_request_start");
+		self.externalities.http_request_start(method, uri, meta)
+	}
+
+	fn http_request_add_header(&mut self, request_id: HttpRequestId, name: &str, value: &str) -> Result<(), ()> {
+		self.check(Capability::Http, "http_request_add_header");
+		self.externalities.http_request_add_header(request_id, name, value)
+	}
+
+	fn http_request_write_body(
+		&mut self,
+		request_id: HttpRequestId,
+		chunk: &[u8],
+		deadline: Option<Timestamp>
+	) -> Result<(), HttpError> {
+		self.check(Capability::Http, "http_request_write_body");
+		self.externalities.http_request_write_body(request_id, chunk, deadline)
+	}
+
+	fn http_response_wait(&mut self, ids: &[HttpRequestId], deadline: Option<Timestamp>) -> Vec<HttpRequestStatus> {
+		self.check(Capability::Http, "http_response_wait");
+		self.externalities.http_response_wait(ids, deadline)
+	}
+
+	fn http_response_headers(&mut self, request_id: HttpRequestId) -> Vec<(Vec<u8>, Vec<u8>)> {
+		self.check(Capability::Http, "http_response_headers");
+		self.externalities.http_response_headers(request_id)
+	}
+
+	fn http_response_read_body(
+		&mut self,
+		request_id: HttpRequestId,
+		buffer: &mut [u8],
+		deadline: Option<Timestamp>
+	) -> Result<usize, HttpError> {
+		self.check(Capability::Http, "http_response_read_body");
+		self.externalities.http_response_read_body(request_id, buffer, deadline)
+	}
+}
 
 
 #[cfg(test)]
@@ -443,4 +675,18 @@ mod tests {
 		assert_eq!(t.sub(Duration::from_millis(10)), Timestamp(0));
 		assert_eq!(t.diff(&Timestamp(3)), Duration(2));
 	}
+
+	#[test]
+	fn capabilities() {
+		let none = Capabilities::none();
+		let all = Capabilities::all();
+		let some = Capabilities::from(&[Capability::Keystore, Capability::Randomness][..]);
+
+		assert!(!none.has(Capability::Keystore));
+		assert!(all.has(Capability::Keystore));
+		assert!(some.has(Capability::Keystore));
+		assert!(!none.has(Capability::TransactionPool));
+		assert!(all.has(Capability::TransactionPool));
+		assert!(!some.has(Capability::TransactionPool));
+	}
 }
diff --git a/core/rpc-servers/Cargo.toml b/core/rpc-servers/Cargo.toml
index 54a4b68eab9bf..d4befd52e9f7a 100644
--- a/core/rpc-servers/Cargo.toml
+++ b/core/rpc-servers/Cargo.toml
@@ -5,12 +5,12 @@ authors = ["Parity Technologies <admin@parity.io>"]
 edition = "2018"
 
 [dependencies]
-jsonrpc-core = "13.0.0"
-pubsub = { package = "jsonrpc-pubsub", version = "13.0.0" }
+jsonrpc-core = "13.1.0"
+pubsub = { package = "jsonrpc-pubsub", version = "13.1.0" }
 log = "0.4"
 serde = "1.0"
 sr-primitives = { path = "../sr-primitives" }
 
 [target.'cfg(not(target_os = "unknown"))'.dependencies]
-http = { package = "jsonrpc-http-server", version = "13.0.0" }
-ws = { package = "jsonrpc-ws-server", version = "13.0.0" }
+http = { package = "jsonrpc-http-server", version = "13.1.0" }
+ws = { package = "jsonrpc-ws-server", version = "13.1.0" }
diff --git a/core/rpc/Cargo.toml b/core/rpc/Cargo.toml
index 0a9cf108c9ede..234761708e7fe 100644
--- a/core/rpc/Cargo.toml
+++ b/core/rpc/Cargo.toml
@@ -8,17 +8,16 @@ edition = "2018"
 derive_more = "0.14.0"
 futures = "0.1"
 futures03 = { package = "futures-preview", version = "0.3.0-alpha.17", features = ["compat"] }
-jsonrpc-core = "13.0.0"
-jsonrpc-core-client = "13.0.0"
-jsonrpc-pubsub = "13.0.0"
-jsonrpc-derive = "13.0.0"
+jsonrpc-core = "13.1.0"
+jsonrpc-core-client = "13.1.0"
+jsonrpc-pubsub = "13.1.0"
+jsonrpc-derive = "13.1.0"
 log = "0.4"
 parking_lot = "0.9.0"
 codec = { package = "parity-scale-codec", version = "1.0.0" }
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
 client = { package = "substrate-client", path = "../client" }
-substrate-executor = { path = "../executor" }
 network = { package = "substrate-network", path = "../network" }
 primitives = { package = "substrate-primitives", path = "../primitives" }
 session = { package = "substrate-session", path = "../session" }
diff --git a/core/rpc/src/author/error.rs b/core/rpc/src/author/error.rs
index 2fcc8c780dfdb..1ce707f0bb38f 100644
--- a/core/rpc/src/author/error.rs
+++ b/core/rpc/src/author/error.rs
@@ -83,6 +83,8 @@ const POOL_TOO_LOW_PRIORITY: i64 = POOL_INVALID_TX + 4;
 const POOL_CYCLE_DETECTED: i64 = POOL_INVALID_TX + 5;
 /// The transaction was not included to the pool because of the limits.
 const POOL_IMMEDIATELY_DROPPED: i64 = POOL_INVALID_TX + 6;
+/// The key type crypto is not known.
+const UNSUPPORTED_KEY_TYPE: i64 = POOL_INVALID_TX + 7;
 
 impl From<Error> for rpc::Error {
 	fn from(e: Error) -> Self {
@@ -134,6 +136,14 @@ impl From<Error> for rpc::Error {
 				message: "Immediately Dropped" .into(),
 				data: Some("The transaction couldn't enter the pool because of the limit".into()),
 			},
+			Error::UnsupportedKeyType => rpc::Error {
+				code: rpc::ErrorCode::ServerError(UNSUPPORTED_KEY_TYPE),
+				message: "Unknown key type crypto" .into(),
+				data: Some(
+					"The crypto for the given key type is unknown, please add the public key to the \
+					request to insert the key successfully.".into()
+				),
+			},
 			e => errors::internal(e),
 		}
 	}
diff --git a/core/rpc/src/author/mod.rs b/core/rpc/src/author/mod.rs
index 6e2d7aa92abc9..0290a534ea549 100644
--- a/core/rpc/src/author/mod.rs
+++ b/core/rpc/src/author/mod.rs
@@ -162,7 +162,7 @@ impl<B, E, P, RA> AuthorApi<ExHash<P>, BlockHash<P>> for Author<B, E, P, RA> whe
 			Some(public) => public.0,
 			None => {
 				let maybe_public = match key_type {
-					key_types::BABE | key_types::IM_ONLINE | key_types::SR25519 =>
+					key_types::BABE | key_types::SR25519 =>
 						sr25519::Pair::from_string(&suri, maybe_password)
 							.map(|pair| pair.public().to_raw_vec()),
 					key_types::GRANDPA | key_types::ED25519 =>
diff --git a/core/rpc/src/chain/mod.rs b/core/rpc/src/chain/mod.rs
index 9b8192e660e9b..cb0235e13bb79 100644
--- a/core/rpc/src/chain/mod.rs
+++ b/core/rpc/src/chain/mod.rs
@@ -67,19 +67,19 @@ pub trait ChainApi<Number, Hash, Header, SignedBlock> {
 	#[pubsub(
 		subscription = "chain_newHead",
 		subscribe,
-		name = "chain_subscribeNewHead",
-		alias("subscribe_newHead")
+		name = "chain_subscribeNewHeads",
+		alias("subscribe_newHead", "chain_subscribeNewHead")
 	)]
-	fn subscribe_new_head(&self, metadata: Self::Metadata, subscriber: Subscriber<Header>);
+	fn subscribe_new_heads(&self, metadata: Self::Metadata, subscriber: Subscriber<Header>);
 
 	/// Unsubscribe from new head subscription.
 	#[pubsub(
 		subscription = "chain_newHead",
 		unsubscribe,
-		name = "chain_unsubscribeNewHead",
-		alias("unsubscribe_newHead")
+		name = "chain_unsubscribeNewHeads",
+		alias("unsubscribe_newHead", "chain_unsubscribeNewHead")
 	)]
-	fn unsubscribe_new_head(&self, metadata: Option<Self::Metadata>, id: SubscriptionId) -> RpcResult<bool>;
+	fn unsubscribe_new_heads(&self, metadata: Option<Self::Metadata>, id: SubscriptionId) -> RpcResult<bool>;
 
 	/// New head subscription
 	#[pubsub(
@@ -199,7 +199,7 @@ impl<B, E, Block, RA> ChainApi<NumberFor<Block>, Block::Hash, Block::Header, Sig
 		Ok(self.client.info().chain.finalized_hash)
 	}
 
-	fn subscribe_new_head(&self, _metadata: Self::Metadata, subscriber: Subscriber<Block::Header>) {
+	fn subscribe_new_heads(&self, _metadata: Self::Metadata, subscriber: Subscriber<Block::Header>) {
 		self.subscribe_headers(
 			subscriber,
 			|| self.block_hash(None.into()),
@@ -210,7 +210,7 @@ impl<B, E, Block, RA> ChainApi<NumberFor<Block>, Block::Hash, Block::Header, Sig
 		)
 	}
 
-	fn unsubscribe_new_head(&self, _metadata: Option<Self::Metadata>, id: SubscriptionId) -> RpcResult<bool> {
+	fn unsubscribe_new_heads(&self, _metadata: Option<Self::Metadata>, id: SubscriptionId) -> RpcResult<bool> {
 		Ok(self.subscriptions.cancel(id))
 	}
 
diff --git a/core/rpc/src/chain/tests.rs b/core/rpc/src/chain/tests.rs
index e6fa4d94e5b0d..36157df71df42 100644
--- a/core/rpc/src/chain/tests.rs
+++ b/core/rpc/src/chain/tests.rs
@@ -202,7 +202,7 @@ fn should_notify_about_latest_block() {
 			subscriptions: Subscriptions::new(Arc::new(remote)),
 		};
 
-		api.subscribe_new_head(Default::default(), subscriber);
+		api.subscribe_new_heads(Default::default(), subscriber);
 
 		// assert id assigned
 		assert_eq!(core.block_on(id), Ok(Ok(SubscriptionId::Number(1))));
diff --git a/core/rpc/src/state/tests.rs b/core/rpc/src/state/tests.rs
index 6b4ddc9b920bc..07e009d1795cd 100644
--- a/core/rpc/src/state/tests.rs
+++ b/core/rpc/src/state/tests.rs
@@ -25,20 +25,24 @@ use test_client::{
 	consensus::BlockOrigin,
 	runtime,
 };
-use substrate_executor::NativeExecutionDispatch;
 
 #[test]
 fn should_return_storage() {
+	const KEY: &[u8] = b":mock";
+	const VALUE: &[u8] = b"hello world";
+
 	let core = tokio::runtime::Runtime::new().unwrap();
-	let client = Arc::new(test_client::new());
+	let client = TestClientBuilder::new()
+		.add_extra_storage(KEY.to_vec(), VALUE.to_vec())
+		.build();
 	let genesis_hash = client.genesis_hash();
-	let client = State::new(client, Subscriptions::new(Arc::new(core.executor())));
-	let key = StorageKey(b":code".to_vec());
+	let client = State::new(Arc::new(client), Subscriptions::new(Arc::new(core.executor())));
+	let key = StorageKey(KEY.to_vec());
 
 	assert_eq!(
 		client.storage(key.clone(), Some(genesis_hash).into())
 			.map(|x| x.map(|x| x.0.len())).unwrap().unwrap() as usize,
-		LocalExecutor::native_equivalent().len(),
+		VALUE.len(),
 	);
 	assert_matches!(
 		client.storage_hash(key.clone(), Some(genesis_hash).into()).map(|x| x.is_some()),
@@ -46,7 +50,7 @@ fn should_return_storage() {
 	);
 	assert_eq!(
 		client.storage_size(key.clone(), None).unwrap().unwrap() as usize,
-		LocalExecutor::native_equivalent().len(),
+		VALUE.len(),
 	);
 }
 
@@ -262,10 +266,12 @@ fn should_return_runtime_version() {
 		[\"0xc6e9a76309f39b09\",1],[\"0xdd718d5cc53262d4\",1],[\"0xcbca25e39f142387\",1],\
 		[\"0xf78b278be53f454c\",1],[\"0xab3c0572291feb8b\",1]]}";
 
-	assert_eq!(
-		serde_json::to_string(&api.runtime_version(None.into()).unwrap()).unwrap(),
-		result,
-	);
+	let runtime_version = api.runtime_version(None.into()).unwrap();
+	let serialized = serde_json::to_string(&runtime_version).unwrap();
+	assert_eq!(serialized, result);
+
+	let deserialized: RuntimeVersion = serde_json::from_str(result).unwrap();
+	assert_eq!(deserialized, runtime_version);
 }
 
 #[test]
diff --git a/core/service/src/builder.rs b/core/service/src/builder.rs
new file mode 100644
index 0000000000000..3b079e549d8cd
--- /dev/null
+++ b/core/service/src/builder.rs
@@ -0,0 +1,809 @@
+// Copyright 2017-2019 Parity Technologies (UK) Ltd.
+// This file is part of Substrate.
+
+// Substrate is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Substrate is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Substrate.  If not, see <http://www.gnu.org/licenses/>.
+
+use crate::{NewService, NetworkStatus, NetworkState, error::{self, Error}, DEFAULT_PROTOCOL_ID};
+use crate::{SpawnTaskHandle, start_rpc_servers, build_network_future, TransactionPoolAdapter};
+use crate::TaskExecutor;
+use crate::config::Configuration;
+use client::{BlockchainEvents, Client, runtime_api};
+use codec::{Decode, Encode, IoReader};
+use consensus_common::import_queue::ImportQueue;
+use futures::{prelude::*, sync::mpsc};
+use futures03::{FutureExt as _, compat::Compat, StreamExt as _, TryStreamExt as _};
+use keystore::{Store as Keystore, KeyStorePtr};
+use log::{info, warn};
+use network::{FinalityProofProvider, OnDemand, NetworkService, NetworkStateInfo};
+use network::{config::BoxFinalityProofRequestBuilder, specialization::NetworkSpecialization};
+use parking_lot::{Mutex, RwLock};
+use primitives::{Blake2Hasher, H256, Hasher};
+use rpc::{self, system::SystemInfo};
+use sr_primitives::{BuildStorage, generic::BlockId};
+use sr_primitives::traits::{Block as BlockT, ProvideRuntimeApi, NumberFor, One, Zero, Header, SaturatedConversion};
+use substrate_executor::{NativeExecutor, NativeExecutionDispatch};
+use serde::{Serialize, de::DeserializeOwned};
+use std::{io::{Read, Write, Seek}, marker::PhantomData, sync::Arc, sync::atomic::AtomicBool};
+use sysinfo::{get_current_pid, ProcessExt, System, SystemExt};
+use tel::{telemetry, SUBSTRATE_INFO};
+use transaction_pool::txpool::{self, ChainApi, Pool as TransactionPool};
+
+/// Aggregator for the components required to build a service.
+///
+/// # Usage
+///
+/// Call [`ServiceBuilder::new_full`] or [`ServiceBuilder::new_light`], then call the various
+/// `with_` methods to add the required components that you built yourself:
+///
+/// - [`with_select_chain`](ServiceBuilder::with_select_chain)
+/// - [`with_import_queue`](ServiceBuilder::with_import_queue)
+/// - [`with_network_protocol`](ServiceBuilder::with_network_protocol)
+/// - [`with_finality_proof_provider`](ServiceBuilder::with_finality_proof_provider)
+/// - [`with_transaction_pool`](ServiceBuilder::with_transaction_pool)
+///
+/// After this is done, call [`build`](ServiceBuilder::build) to construct the service.
+///
+/// The order in which the `with_*` methods are called doesn't matter, as the correct binding of
+/// generics is done when you call `build`.
+///
+pub struct ServiceBuilder<TBl, TRtApi, TCfg, TGen, TCl, TFchr, TSc, TImpQu, TFprb, TFpp, TNetP, TExPool, TRpc> {
+	config: Configuration<TCfg, TGen>,
+	client: Arc<TCl>,
+	keystore: Arc<RwLock<Keystore>>,
+	fetcher: Option<TFchr>,
+	select_chain: Option<TSc>,
+	import_queue: TImpQu,
+	finality_proof_request_builder: Option<TFprb>,
+	finality_proof_provider: Option<TFpp>,
+	network_protocol: TNetP,
+	transaction_pool: Arc<TExPool>,
+	rpc_extensions: TRpc,
+	marker: PhantomData<(TBl, TRtApi)>,
+}
+
+impl<TCfg, TGen> ServiceBuilder<(), (), TCfg, TGen, (), (), (), (), (), (), (), (), ()>
+where TGen: Serialize + DeserializeOwned + BuildStorage {
+	/// Start the service builder with a configuration.
+	pub fn new_full<TBl: BlockT<Hash=H256>, TRtApi, TExecDisp: NativeExecutionDispatch>(
+		config: Configuration<TCfg, TGen>
+	) -> Result<ServiceBuilder<
+		TBl,
+		TRtApi,
+		TCfg,
+		TGen,
+		Client<
+			client_db::Backend<TBl>,
+			client::LocalCallExecutor<client_db::Backend<TBl>, NativeExecutor<TExecDisp>>,
+			TBl,
+			TRtApi
+		>,
+		Arc<OnDemand<TBl>>,
+		(),
+		(),
+		BoxFinalityProofRequestBuilder<TBl>,
+		(),
+		(),
+		(),
+		()
+	>, Error> {
+		let keystore = Keystore::open(config.keystore_path.clone(), config.keystore_password.clone())?;
+
+		let db_settings = client_db::DatabaseSettings {
+			cache_size: None,
+			state_cache_size: config.state_cache_size,
+			state_cache_child_ratio:
+				config.state_cache_child_ratio.map(|v| (v, 100)),
+			path: config.database_path.clone(),
+			pruning: config.pruning.clone(),
+		};
+
+		let executor = NativeExecutor::<TExecDisp>::new(config.default_heap_pages);
+
+		let client = Arc::new(client_db::new_client(
+			db_settings,
+			executor,
+			&config.chain_spec,
+			config.execution_strategies.clone(),
+			Some(keystore.clone()),
+		)?);
+
+		Ok(ServiceBuilder {
+			config,
+			client,
+			keystore,
+			fetcher: None,
+			select_chain: None,
+			import_queue: (),
+			finality_proof_request_builder: None,
+			finality_proof_provider: None,
+			network_protocol: (),
+			transaction_pool: Arc::new(()),
+			rpc_extensions: Default::default(),
+			marker: PhantomData,
+		})
+	}
+
+	/// Start the service builder with a configuration.
+	pub fn new_light<TBl: BlockT<Hash=H256>, TRtApi, TExecDisp: NativeExecutionDispatch + 'static>(
+		config: Configuration<TCfg, TGen>
+	) -> Result<ServiceBuilder<
+		TBl,
+		TRtApi,
+		TCfg,
+		TGen,
+		Client<
+			client::light::backend::Backend<client_db::light::LightStorage<TBl>, network::OnDemand<TBl>, Blake2Hasher>,
+			client::light::call_executor::RemoteOrLocalCallExecutor<
+				TBl,
+				client::light::backend::Backend<
+					client_db::light::LightStorage<TBl>,
+					network::OnDemand<TBl>,
+					Blake2Hasher
+				>,
+				client::light::call_executor::RemoteCallExecutor<
+					client::light::blockchain::Blockchain<
+						client_db::light::LightStorage<TBl>,
+						network::OnDemand<TBl>
+					>,
+					network::OnDemand<TBl>,
+				>,
+				client::LocalCallExecutor<
+					client::light::backend::Backend<
+						client_db::light::LightStorage<TBl>,
+						network::OnDemand<TBl>,
+						Blake2Hasher
+					>,
+					NativeExecutor<TExecDisp>
+				>
+			>,
+			TBl,
+			TRtApi
+		>,
+		Arc<OnDemand<TBl>>,
+		(),
+		(),
+		BoxFinalityProofRequestBuilder<TBl>,
+		(),
+		(),
+		(),
+		()
+	>, Error> {
+		let keystore = Keystore::open(config.keystore_path.clone(), config.keystore_password.clone())?;
+
+		let db_settings = client_db::DatabaseSettings {
+			cache_size: config.database_cache_size.map(|u| u as usize),
+			state_cache_size: config.state_cache_size,
+			state_cache_child_ratio:
+				config.state_cache_child_ratio.map(|v| (v, 100)),
+			path: config.database_path.clone(),
+			pruning: config.pruning.clone(),
+		};
+
+		let executor = NativeExecutor::<TExecDisp>::new(config.default_heap_pages);
+
+		let db_storage = client_db::light::LightStorage::new(db_settings)?;
+		let light_blockchain = client::light::new_light_blockchain(db_storage);
+		let fetch_checker = Arc::new(client::light::new_fetch_checker(light_blockchain.clone(), executor.clone()));
+		let fetcher = Arc::new(network::OnDemand::new(fetch_checker));
+		let client_backend = client::light::new_light_backend(light_blockchain, fetcher.clone());
+		let client = client::light::new_light(client_backend, fetcher.clone(), &config.chain_spec, executor)?;
+
+		Ok(ServiceBuilder {
+			config,
+			client: Arc::new(client),
+			keystore,
+			fetcher: Some(fetcher),
+			select_chain: None,
+			import_queue: (),
+			finality_proof_request_builder: None,
+			finality_proof_provider: None,
+			network_protocol: (),
+			transaction_pool: Arc::new(()),
+			rpc_extensions: Default::default(),
+			marker: PhantomData,
+		})
+	}
+}
+
+impl<TBl, TRtApi, TCfg, TGen, TCl, TFchr, TSc, TImpQu, TFprb, TFpp, TNetP, TExPool, TRpc>
+	ServiceBuilder<TBl, TRtApi, TCfg, TGen, TCl, TFchr, TSc, TImpQu, TFprb, TFpp, TNetP, TExPool, TRpc> {
+
+	/// Returns a reference to the client that was stored in this builder.
+	pub fn client(&self) -> &Arc<TCl> {
+		&self.client
+	}
+
+	/// Returns a reference to the select-chain that was stored in this builder.
+	pub fn select_chain(&self) -> Option<&TSc> {
+		self.select_chain.as_ref()
+	}
+
+	/// Defines which head-of-chain strategy to use.
+	pub fn with_opt_select_chain<USc>(
+		mut self,
+		select_chain_builder: impl FnOnce(&mut Configuration<TCfg, TGen>, Arc<TCl>) -> Result<Option<USc>, Error>
+	) -> Result<ServiceBuilder<TBl, TRtApi, TCfg, TGen, TCl, TFchr, USc, TImpQu, TFprb, TFpp,
+		TNetP, TExPool, TRpc>, Error> {
+		let select_chain = select_chain_builder(&mut self.config, self.client.clone())?;
+
+		Ok(ServiceBuilder {
+			config: self.config,
+			client: self.client,
+			keystore: self.keystore,
+			fetcher: self.fetcher,
+			select_chain,
+			import_queue: self.import_queue,
+			finality_proof_request_builder: self.finality_proof_request_builder,
+			finality_proof_provider: self.finality_proof_provider,
+			network_protocol: self.network_protocol,
+			transaction_pool: self.transaction_pool,
+			rpc_extensions: self.rpc_extensions,
+			marker: self.marker,
+		})
+	}
+
+	/// Defines which head-of-chain strategy to use.
+	pub fn with_select_chain<USc>(
+		self,
+		builder: impl FnOnce(&mut Configuration<TCfg, TGen>, Arc<TCl>) -> Result<USc, Error>
+	) -> Result<ServiceBuilder<TBl, TRtApi, TCfg, TGen, TCl, TFchr, USc, TImpQu, TFprb, TFpp,
+		TNetP, TExPool, TRpc>, Error> {
+		self.with_opt_select_chain(|cfg, cl| builder(cfg, cl).map(Option::Some))
+	}
+
+	/// Defines which import queue to use.
+	pub fn with_import_queue<UImpQu>(
+		mut self,
+		builder: impl FnOnce(&mut Configuration<TCfg, TGen>, Arc<TCl>, Option<TSc>, Arc<TExPool>)
+			-> Result<UImpQu, Error>
+	) -> Result<ServiceBuilder<TBl, TRtApi, TCfg, TGen, TCl, TFchr, TSc, UImpQu, TFprb, TFpp,
+			TNetP, TExPool, TRpc>, Error>
+	where TSc: Clone {
+		let import_queue = builder(
+			&mut self.config,
+			self.client.clone(),
+			self.select_chain.clone(),
+			self.transaction_pool.clone()
+		)?;
+
+		Ok(ServiceBuilder {
+			config: self.config,
+			client: self.client,
+			keystore: self.keystore,
+			fetcher: self.fetcher,
+			select_chain: self.select_chain,
+			import_queue,
+			finality_proof_request_builder: self.finality_proof_request_builder,
+			finality_proof_provider: self.finality_proof_provider,
+			network_protocol: self.network_protocol,
+			transaction_pool: self.transaction_pool,
+			rpc_extensions: self.rpc_extensions,
+			marker: self.marker,
+		})
+	}
+
+	/// Defines which network specialization protocol to use.
+	pub fn with_network_protocol<UNetP>(
+		self,
+		network_protocol_builder: impl FnOnce(&Configuration<TCfg, TGen>) -> Result<UNetP, Error>
+	) -> Result<ServiceBuilder<TBl, TRtApi, TCfg, TGen, TCl, TFchr, TSc, TImpQu, TFprb, TFpp,
+		UNetP, TExPool, TRpc>, Error> {
+		let network_protocol = network_protocol_builder(&self.config)?;
+
+		Ok(ServiceBuilder {
+			config: self.config,
+			client: self.client,
+			keystore: self.keystore,
+			fetcher: self.fetcher,
+			select_chain: self.select_chain,
+			import_queue: self.import_queue,
+			finality_proof_request_builder: self.finality_proof_request_builder,
+			finality_proof_provider: self.finality_proof_provider,
+			network_protocol,
+			transaction_pool: self.transaction_pool,
+			rpc_extensions: self.rpc_extensions,
+			marker: self.marker,
+		})
+	}
+
+	/// Defines which strategy to use for providing finality proofs.
+	pub fn with_opt_finality_proof_provider(
+		self,
+		builder: impl FnOnce(Arc<TCl>) -> Result<Option<Arc<FinalityProofProvider<TBl>>>, Error>
+	) -> Result<ServiceBuilder<
+		TBl,
+		TRtApi,
+		TCfg,
+		TGen,
+		TCl,
+		TFchr,
+		TSc,
+		TImpQu,
+		TFprb,
+		Arc<FinalityProofProvider<TBl>>,
+		TNetP,
+		TExPool,
+		TRpc
+	>, Error> {
+		let finality_proof_provider = builder(self.client.clone())?;
+
+		Ok(ServiceBuilder {
+			config: self.config,
+			client: self.client,
+			keystore: self.keystore,
+			fetcher: self.fetcher,
+			select_chain: self.select_chain,
+			import_queue: self.import_queue,
+			finality_proof_request_builder: self.finality_proof_request_builder,
+			finality_proof_provider,
+			network_protocol: self.network_protocol,
+			transaction_pool: self.transaction_pool,
+			rpc_extensions: self.rpc_extensions,
+			marker: self.marker,
+		})
+	}
+
+	/// Defines which strategy to use for providing finality proofs.
+	pub fn with_finality_proof_provider(
+		self,
+		build: impl FnOnce(Arc<TCl>) -> Result<Arc<FinalityProofProvider<TBl>>, Error>
+	) -> Result<ServiceBuilder<
+		TBl,
+		TRtApi,
+		TCfg,
+		TGen,
+		TCl,
+		TFchr,
+		TSc,
+		TImpQu,
+		TFprb,
+		Arc<FinalityProofProvider<TBl>>,
+		TNetP,
+		TExPool,
+		TRpc
+	>, Error> {
+		self.with_opt_finality_proof_provider(|client| build(client).map(Option::Some))
+	}
+
+	/// Defines which import queue to use.
+	pub fn with_import_queue_and_opt_fprb<UImpQu, UFprb>(
+		mut self,
+		builder: impl FnOnce(&mut Configuration<TCfg, TGen>, Arc<TCl>, Option<TSc>, Arc<TExPool>)
+			-> Result<(UImpQu, Option<UFprb>), Error>
+	) -> Result<ServiceBuilder<TBl, TRtApi, TCfg, TGen, TCl, TFchr, TSc, UImpQu, UFprb, TFpp,
+		TNetP, TExPool, TRpc>, Error>
+	where TSc: Clone {
+		let (import_queue, fprb) = builder(
+			&mut self.config,
+			self.client.clone(),
+			self.select_chain.clone(),
+			self.transaction_pool.clone()
+		)?;
+
+		Ok(ServiceBuilder {
+			config: self.config,
+			client: self.client,
+			keystore: self.keystore,
+			fetcher: self.fetcher,
+			select_chain: self.select_chain,
+			import_queue,
+			finality_proof_request_builder: fprb,
+			finality_proof_provider: self.finality_proof_provider,
+			network_protocol: self.network_protocol,
+			transaction_pool: self.transaction_pool,
+			rpc_extensions: self.rpc_extensions,
+			marker: self.marker,
+		})
+	}
+
+	/// Defines which import queue to use.
+	pub fn with_import_queue_and_fprb<UImpQu, UFprb>(
+		self,
+		builder: impl FnOnce(&mut Configuration<TCfg, TGen>, Arc<TCl>, Option<TSc>, Arc<TExPool>)
+			-> Result<(UImpQu, UFprb), Error>
+	) -> Result<ServiceBuilder<TBl, TRtApi, TCfg, TGen, TCl, TFchr, TSc, UImpQu, UFprb, TFpp,
+			TNetP, TExPool, TRpc>, Error>
+	where TSc: Clone {
+		self.with_import_queue_and_opt_fprb(|cfg, cl, sc, tx| builder(cfg, cl, sc, tx).map(|(q, f)| (q, Some(f))))
+	}
+
+	/// Defines which transaction pool to use.
+	pub fn with_transaction_pool<UExPool>(
+		self,
+		transaction_pool_builder: impl FnOnce(transaction_pool::txpool::Options, Arc<TCl>) -> Result<UExPool, Error>
+	) -> Result<ServiceBuilder<TBl, TRtApi, TCfg, TGen, TCl, TFchr, TSc, TImpQu, TFprb, TFpp,
+		TNetP, UExPool, TRpc>, Error> {
+		let transaction_pool = transaction_pool_builder(self.config.transaction_pool.clone(), self.client.clone())?;
+
+		Ok(ServiceBuilder {
+			config: self.config,
+			client: self.client,
+			keystore: self.keystore,
+			fetcher: self.fetcher,
+			select_chain: self.select_chain,
+			import_queue: self.import_queue,
+			finality_proof_request_builder: self.finality_proof_request_builder,
+			finality_proof_provider: self.finality_proof_provider,
+			network_protocol: self.network_protocol,
+			transaction_pool: Arc::new(transaction_pool),
+			rpc_extensions: self.rpc_extensions,
+			marker: self.marker,
+		})
+	}
+
+	/// Defines the RPC extensions to use.
+	pub fn with_rpc_extensions<URpc>(
+		self,
+		rpc_ext_builder: impl FnOnce(Arc<TCl>, Arc<TExPool>) -> URpc
+	) -> Result<ServiceBuilder<TBl, TRtApi, TCfg, TGen, TCl, TFchr, TSc, TImpQu, TFprb, TFpp,
+		TNetP, TExPool, URpc>, Error> {
+		let rpc_extensions = rpc_ext_builder(self.client.clone(), self.transaction_pool.clone());
+
+		Ok(ServiceBuilder {
+			config: self.config,
+			client: self.client,
+			keystore: self.keystore,
+			fetcher: self.fetcher,
+			select_chain: self.select_chain,
+			import_queue: self.import_queue,
+			finality_proof_request_builder: self.finality_proof_request_builder,
+			finality_proof_provider: self.finality_proof_provider,
+			network_protocol: self.network_protocol,
+			transaction_pool: self.transaction_pool,
+			rpc_extensions,
+			marker: self.marker,
+		})
+	}
+}
+
+/// Implemented on `ServiceBuilder`. Allows importing blocks once you have given all the required
+/// components to the builder.
+pub trait ServiceBuilderImport {
+	/// Starts the process of importing blocks.
+	fn import_blocks(
+		self,
+		exit: impl Future<Item=(),Error=()> + Send + 'static,
+		input: impl Read + Seek,
+	) -> Result<Box<dyn Future<Item = (), Error = ()> + Send>, Error>;
+}
+
+/// Implemented on `ServiceBuilder`. Allows exporting blocks once you have given all the required
+/// components to the builder.
+pub trait ServiceBuilderExport {
+	/// Type of block of the builder.
+	type Block: BlockT;
+
+	/// Performs the blocks export.
+	fn export_blocks(
+		&self,
+		exit: impl Future<Item=(),Error=()> + Send + 'static,
+		output: impl Write,
+		from: NumberFor<Self::Block>,
+		to: Option<NumberFor<Self::Block>>,
+		json: bool
+	) -> Result<(), Error>;
+}
+
+/// Implemented on `ServiceBuilder`. Allows reverting the chain once you have given all the
+/// required components to the builder.
+pub trait ServiceBuilderRevert {
+	/// Type of block of the builder.
+	type Block: BlockT;
+
+	/// Performs a revert of `blocks` bocks.
+	fn revert_chain(
+		&self,
+		blocks: NumberFor<Self::Block>
+	) -> Result<(), Error>;
+}
+
+impl<TBl, TRtApi, TCfg, TGen, TBackend, TExec, TFchr, TSc, TImpQu, TFprb, TFpp, TNetP, TExPool, TRpc>
+	ServiceBuilderImport for ServiceBuilder<TBl, TRtApi, TCfg, TGen, Client<TBackend, TExec, TBl, TRtApi>,
+		TFchr, TSc, TImpQu, TFprb, TFpp, TNetP, TExPool, TRpc>
+where
+	TBl: BlockT<Hash = <Blake2Hasher as Hasher>::Out>,
+	TBackend: 'static + client::backend::Backend<TBl, Blake2Hasher> + Send,
+	TExec: 'static + client::CallExecutor<TBl, Blake2Hasher> + Send + Sync + Clone,
+	TImpQu: 'static + ImportQueue<TBl>,
+	TRtApi: 'static + Send + Sync,
+{
+	fn import_blocks(
+		self,
+		exit: impl Future<Item=(),Error=()> + Send + 'static,
+		input: impl Read + Seek,
+	) -> Result<Box<dyn Future<Item = (), Error = ()> + Send>, Error> {
+		let client = self.client;
+		let mut queue = self.import_queue;
+		import_blocks!(TBl, client, queue, exit, input)
+			.map(|f| Box::new(f) as Box<_>)
+	}
+}
+
+impl<TBl, TRtApi, TCfg, TGen, TBackend, TExec, TFchr, TSc, TImpQu, TFprb, TFpp, TNetP, TExPool, TRpc>
+	ServiceBuilderExport for ServiceBuilder<TBl, TRtApi, TCfg, TGen, Client<TBackend, TExec, TBl, TRtApi>,
+		TFchr, TSc, TImpQu, TFprb, TFpp, TNetP, TExPool, TRpc>
+where
+	TBl: BlockT<Hash = <Blake2Hasher as Hasher>::Out>,
+	TBackend: 'static + client::backend::Backend<TBl, Blake2Hasher> + Send,
+	TExec: 'static + client::CallExecutor<TBl, Blake2Hasher> + Send + Sync + Clone
+{
+	type Block = TBl;
+
+	fn export_blocks(
+		&self,
+		exit: impl Future<Item=(),Error=()> + Send + 'static,
+		mut output: impl Write,
+		from: NumberFor<TBl>,
+		to: Option<NumberFor<TBl>>,
+		json: bool
+	) -> Result<(), Error> {
+		let client = &self.client;
+		export_blocks!(client, exit, output, from, to, json)
+	}
+}
+
+impl<TBl, TRtApi, TCfg, TGen, TBackend, TExec, TFchr, TSc, TImpQu, TFprb, TFpp, TNetP, TExPool, TRpc>
+	ServiceBuilderRevert for ServiceBuilder<TBl, TRtApi, TCfg, TGen, Client<TBackend, TExec, TBl, TRtApi>,
+		TFchr, TSc, TImpQu, TFprb, TFpp, TNetP, TExPool, TRpc>
+where
+	TBl: BlockT<Hash = <Blake2Hasher as Hasher>::Out>,
+	TBackend: 'static + client::backend::Backend<TBl, Blake2Hasher> + Send,
+	TExec: 'static + client::CallExecutor<TBl, Blake2Hasher> + Send + Sync + Clone
+{
+	type Block = TBl;
+
+	fn revert_chain(
+		&self,
+		blocks: NumberFor<TBl>
+	) -> Result<(), Error> {
+		let client = &self.client;
+		revert_chain!(client, blocks)
+	}
+}
+
+impl<TBl, TRtApi, TCfg, TGen, TBackend, TExec, TSc, TImpQu, TNetP, TExPoolApi, TRpc>
+ServiceBuilder<
+	TBl,
+	TRtApi,
+	TCfg,
+	TGen,
+	Client<TBackend, TExec, TBl, TRtApi>,
+	Arc<OnDemand<TBl>>,
+	TSc,
+	TImpQu,
+	BoxFinalityProofRequestBuilder<TBl>,
+	Arc<FinalityProofProvider<TBl>>,
+	TNetP,
+	TransactionPool<TExPoolApi>,
+	TRpc
+> where
+	Client<TBackend, TExec, TBl, TRtApi>: ProvideRuntimeApi,
+	<Client<TBackend, TExec, TBl, TRtApi> as ProvideRuntimeApi>::Api:
+		runtime_api::Metadata<TBl> +
+		offchain::OffchainWorkerApi<TBl> +
+		runtime_api::TaggedTransactionQueue<TBl> +
+		session::SessionKeys<TBl>,
+	TBl: BlockT<Hash = <Blake2Hasher as Hasher>::Out>,
+	TRtApi: 'static + Send + Sync,
+	TCfg: Default,
+	TGen: Serialize + DeserializeOwned + BuildStorage,
+	TBackend: 'static + client::backend::Backend<TBl, Blake2Hasher> + Send,
+	TExec: 'static + client::CallExecutor<TBl, Blake2Hasher> + Send + Sync + Clone,
+	TSc: Clone,
+	TImpQu: 'static + ImportQueue<TBl>,
+	TNetP: NetworkSpecialization<TBl>,
+	TExPoolApi: 'static + ChainApi<Block = TBl, Hash = <TBl as BlockT>::Hash>,
+	TRpc: rpc::RpcExtension<rpc::Metadata> + Clone,
+{
+	/// Builds the service.
+	pub fn build(self) -> Result<NewService<
+		Configuration<TCfg, TGen>,
+		TBl,
+		Client<TBackend, TExec, TBl, TRtApi>,
+		TSc,
+		NetworkStatus<TBl>,
+		NetworkService<TBl, TNetP, <TBl as BlockT>::Hash>,
+		TransactionPool<TExPoolApi>,
+		offchain::OffchainWorkers<
+			Client<TBackend, TExec, TBl, TRtApi>,
+			TBackend::OffchainStorage,
+			TBl
+		>,
+	>, Error> {
+		let mut config = self.config;
+		session::generate_initial_session_keys(
+			self.client.clone(),
+			config.dev_key_seed.clone().map(|s| vec![s]).unwrap_or_default()
+		)?;
+		let (
+			client,
+			fetcher,
+			keystore,
+			select_chain,
+			import_queue,
+			finality_proof_request_builder,
+			finality_proof_provider,
+			network_protocol,
+			transaction_pool,
+			rpc_extensions
+		) = (
+			self.client,
+			self.fetcher,
+			self.keystore,
+			self.select_chain,
+			self.import_queue,
+			self.finality_proof_request_builder,
+			self.finality_proof_provider,
+			self.network_protocol,
+			self.transaction_pool,
+			self.rpc_extensions
+		);
+
+		new_impl!(
+			TBl,
+			config,
+			move |_| -> Result<_, Error> {
+				Ok((
+					client,
+					fetcher,
+					keystore,
+					select_chain,
+					import_queue,
+					finality_proof_request_builder,
+					finality_proof_provider,
+					network_protocol,
+					transaction_pool,
+					rpc_extensions
+				))
+			},
+			|h, c, tx| maintain_transaction_pool(h, c, tx),
+			|n, o, p, ns, v| offchain_workers(n, o, p, ns, v),
+			|c, ssb, si, te, tp, ext, ks| start_rpc(c, ssb, si, te, tp, ext, ks),
+		)
+	}
+}
+
+pub(crate) fn start_rpc<Api, Backend, Block, Executor, PoolApi>(
+	client: Arc<Client<Backend, Executor, Block, Api>>,
+	system_send_back: futures03::channel::mpsc::UnboundedSender<rpc::system::Request<Block>>,
+	rpc_system_info: SystemInfo,
+	task_executor: TaskExecutor,
+	transaction_pool: Arc<TransactionPool<PoolApi>>,
+	rpc_extensions: impl rpc::RpcExtension<rpc::Metadata>,
+	keystore: KeyStorePtr,
+) -> rpc_servers::RpcHandler<rpc::Metadata>
+where
+	Block: BlockT<Hash = <Blake2Hasher as primitives::Hasher>::Out>,
+	Backend: client::backend::Backend<Block, Blake2Hasher> + 'static,
+	Client<Backend, Executor, Block, Api>: ProvideRuntimeApi,
+	<Client<Backend, Executor, Block, Api> as ProvideRuntimeApi>::Api:
+		runtime_api::Metadata<Block> + session::SessionKeys<Block>,
+	Api: Send + Sync + 'static,
+	Executor: client::CallExecutor<Block, Blake2Hasher> + Send + Sync + Clone + 'static,
+	PoolApi: txpool::ChainApi<Hash = Block::Hash, Block = Block> + 'static {
+	use rpc::{chain, state, author, system};
+	let subscriptions = rpc::Subscriptions::new(task_executor.clone());
+	let chain = chain::Chain::new(client.clone(), subscriptions.clone());
+	let state = state::State::new(client.clone(), subscriptions.clone());
+	let author = rpc::author::Author::new(
+		client,
+		transaction_pool,
+		subscriptions,
+		keystore,
+	);
+	let system = system::System::new(rpc_system_info, system_send_back);
+
+	rpc_servers::rpc_handler((
+		state::StateApi::to_delegate(state),
+		chain::ChainApi::to_delegate(chain),
+		author::AuthorApi::to_delegate(author),
+		system::SystemApi::to_delegate(system),
+		rpc_extensions,
+	))
+}
+
+pub(crate) fn maintain_transaction_pool<Api, Backend, Block, Executor, PoolApi>(
+	id: &BlockId<Block>,
+	client: &Client<Backend, Executor, Block, Api>,
+	transaction_pool: &TransactionPool<PoolApi>,
+) -> error::Result<()> where
+	Block: BlockT<Hash = <Blake2Hasher as primitives::Hasher>::Out>,
+	Backend: client::backend::Backend<Block, Blake2Hasher>,
+	Client<Backend, Executor, Block, Api>: ProvideRuntimeApi,
+	<Client<Backend, Executor, Block, Api> as ProvideRuntimeApi>::Api: runtime_api::TaggedTransactionQueue<Block>,
+	Executor: client::CallExecutor<Block, Blake2Hasher>,
+	PoolApi: txpool::ChainApi<Hash = Block::Hash, Block = Block>,
+{
+	// Avoid calling into runtime if there is nothing to prune from the pool anyway.
+	if transaction_pool.status().is_empty() {
+		return Ok(())
+	}
+
+	if let Some(block) = client.block(id)? {
+		let parent_id = BlockId::hash(*block.block.header().parent_hash());
+		let extrinsics = block.block.extrinsics();
+		transaction_pool.prune(id, &parent_id, extrinsics).map_err(|e| format!("{:?}", e))?;
+	}
+
+	Ok(())
+}
+
+pub(crate) fn offchain_workers<Api, Backend, Block, Executor, PoolApi>(
+	number: &NumberFor<Block>,
+	offchain: &offchain::OffchainWorkers<
+		Client<Backend, Executor, Block, Api>,
+		<Backend as client::backend::Backend<Block, Blake2Hasher>>::OffchainStorage,
+		Block
+	>,
+	pool: &Arc<TransactionPool<PoolApi>>,
+	network_state: &Arc<dyn NetworkStateInfo + Send + Sync>,
+	is_validator: bool,
+) -> error::Result<Box<dyn Future<Item = (), Error = ()> + Send>>
+where
+	Block: BlockT<Hash = <Blake2Hasher as primitives::Hasher>::Out>,
+	Backend: client::backend::Backend<Block, Blake2Hasher> + 'static,
+	Api: 'static,
+	<Backend as client::backend::Backend<Block, Blake2Hasher>>::OffchainStorage: 'static,
+	Client<Backend, Executor, Block, Api>: ProvideRuntimeApi + Send + Sync,
+	<Client<Backend, Executor, Block, Api> as ProvideRuntimeApi>::Api: offchain::OffchainWorkerApi<Block>,
+	Executor: client::CallExecutor<Block, Blake2Hasher> + 'static,
+	PoolApi: txpool::ChainApi<Hash = Block::Hash, Block = Block> + 'static,
+{
+	let future = offchain.on_block_imported(number, pool, network_state.clone(), is_validator)
+		.map(|()| Ok(()));
+	Ok(Box::new(Compat::new(future)))
+}
+
+#[cfg(test)]
+mod tests {
+	use super::*;
+	use consensus_common::{BlockOrigin, SelectChain};
+	use substrate_test_runtime_client::{prelude::*, runtime::Transfer};
+
+	#[test]
+	fn should_remove_transactions_from_the_pool() {
+		let (client, longest_chain) = TestClientBuilder::new().build_with_longest_chain();
+		let client = Arc::new(client);
+		let pool = TransactionPool::new(Default::default(), ::transaction_pool::ChainApi::new(client.clone()));
+		let transaction = Transfer {
+			amount: 5,
+			nonce: 0,
+			from: AccountKeyring::Alice.into(),
+			to: Default::default(),
+		}.into_signed_tx();
+		let best = longest_chain.best_chain().unwrap();
+
+		// store the transaction in the pool
+		pool.submit_one(&BlockId::hash(best.hash()), transaction.clone()).unwrap();
+
+		// import the block
+		let mut builder = client.new_block(Default::default()).unwrap();
+		builder.push(transaction.clone()).unwrap();
+		let block = builder.bake().unwrap();
+		let id = BlockId::hash(block.header().hash());
+		client.import(BlockOrigin::Own, block).unwrap();
+
+		// fire notification - this should clean up the queue
+		assert_eq!(pool.status().ready, 1);
+		maintain_transaction_pool(
+			&id,
+			&client,
+			&pool,
+		).unwrap();
+
+		// then
+		assert_eq!(pool.status().ready, 0);
+		assert_eq!(pool.status().future, 0);
+	}
+}
diff --git a/core/service/src/chain_ops.rs b/core/service/src/chain_ops.rs
index c801b81186f18..3a3677798b6ad 100644
--- a/core/service/src/chain_ops.rs
+++ b/core/service/src/chain_ops.rs
@@ -16,44 +16,19 @@
 
 //! Chain utilities.
 
-use std::{self, io::{Read, Write, Seek}};
-use futures::prelude::*;
-use futures03::TryFutureExt as _;
-use log::{info, warn};
-
-use sr_primitives::generic::{SignedBlock, BlockId};
-use sr_primitives::traits::{SaturatedConversion, Zero, One, Block, Header, NumberFor};
-use consensus_common::import_queue::{ImportQueue, IncomingBlock, Link, BlockImportError, BlockImportResult};
-use network::message;
-
-use consensus_common::BlockOrigin;
-use crate::components::{self, Components, ServiceFactory, FactoryFullConfiguration, FactoryBlockNumber, RuntimeGenesis};
-use crate::new_client;
-use codec::{Decode, Encode, IoReader};
+use crate::RuntimeGenesis;
 use crate::error;
 use crate::chain_spec::ChainSpec;
 
-/// Export a range of blocks to a binary stream.
-pub fn export_blocks<F, E, W>(
-	config: FactoryFullConfiguration<F>,
-	exit: E,
-	mut output: W,
-	from: FactoryBlockNumber<F>,
-	to: Option<FactoryBlockNumber<F>>,
-	json: bool
-) -> error::Result<()>
-	where
-	F: ServiceFactory,
-	E: Future<Item=(),Error=()> + Send + 'static,
-	W: Write,
-{
-	let client = new_client::<F>(&config)?;
-	let mut block = from;
+#[macro_export]
+macro_rules! export_blocks {
+($client:ident, $exit:ident, $output:ident, $from:ident, $to:ident, $json:ident) => {{
+	let mut block = $from;
 
-	let last = match to {
+	let last = match $to {
 		Some(v) if v.is_zero() => One::one(),
 		Some(v) => v,
-		None => client.info().chain.best_number,
+		None => $client.info().chain.best_number,
 	};
 
 	if last < block {
@@ -62,28 +37,28 @@ pub fn export_blocks<F, E, W>(
 
 	let (exit_send, exit_recv) = std::sync::mpsc::channel();
 	::std::thread::spawn(move || {
-		let _ = exit.wait();
+		let _ = $exit.wait();
 		let _ = exit_send.send(());
 	});
 	info!("Exporting blocks from #{} to #{}", block, last);
-	if !json {
+	if !$json {
 		let last_: u64 = last.saturated_into::<u64>();
 		let block_: u64 = block.saturated_into::<u64>();
 		let len: u64 = last_ - block_ + 1;
-		output.write(&len.encode())?;
+		$output.write(&len.encode())?;
 	}
 
 	loop {
 		if exit_recv.try_recv().is_ok() {
 			break;
 		}
-		match client.block(&BlockId::number(block))? {
+		match $client.block(&BlockId::number(block))? {
 			Some(block) => {
-				if json {
-					serde_json::to_writer(&mut output, &block)
+				if $json {
+					serde_json::to_writer(&mut $output, &block)
 						.map_err(|e| format!("Error writing JSON: {}", e))?;
 				} else {
-					output.write(&block.encode())?;
+					$output.write(&block.encode())?;
 				}
 			},
 			None => break,
@@ -97,66 +72,59 @@ pub fn export_blocks<F, E, W>(
 		block += One::one();
 	}
 	Ok(())
+}}
 }
 
-struct WaitLink {
-	imported_blocks: u64,
-	has_error: bool,
-}
+#[macro_export]
+macro_rules! import_blocks {
+($block:ty, $client:ident, $queue:ident, $exit:ident, $input:ident) => {{
+	use consensus_common::import_queue::{IncomingBlock, Link, BlockImportError, BlockImportResult};
+	use consensus_common::BlockOrigin;
+	use network::message;
+	use sr_primitives::generic::SignedBlock;
+	use sr_primitives::traits::Block;
+	use futures03::TryFutureExt as _;
+
+	struct WaitLink {
+		imported_blocks: u64,
+		has_error: bool,
+	}
 
-impl WaitLink {
-	fn new() -> WaitLink {
-		WaitLink {
-			imported_blocks: 0,
-			has_error: false,
+	impl WaitLink {
+		fn new() -> WaitLink {
+			WaitLink {
+				imported_blocks: 0,
+				has_error: false,
+			}
 		}
 	}
-}
 
-impl<B: Block> Link<B> for WaitLink {
-	fn blocks_processed(
-		&mut self,
-		imported: usize,
-		_count: usize,
-		results: Vec<(Result<BlockImportResult<NumberFor<B>>, BlockImportError>, B::Hash)>
-	) {
-		self.imported_blocks += imported as u64;
-
-		for result in results {
-			if let (Err(err), hash) = result {
-				warn!("There was an error importing block with hash {:?}: {:?}", hash, err);
-				self.has_error = true;
-				break;
+	impl<B: Block> Link<B> for WaitLink {
+		fn blocks_processed(
+			&mut self,
+			imported: usize,
+			_count: usize,
+			results: Vec<(Result<BlockImportResult<NumberFor<B>>, BlockImportError>, B::Hash)>
+		) {
+			self.imported_blocks += imported as u64;
+
+			for result in results {
+				if let (Err(err), hash) = result {
+					warn!("There was an error importing block with hash {:?}: {:?}", hash, err);
+					self.has_error = true;
+					break;
+				}
 			}
 		}
 	}
-}
-
-/// Returns a future that import blocks from a binary stream.
-pub fn import_blocks<F, E, R>(
-	mut config: FactoryFullConfiguration<F>,
-	exit: E,
-	input: R
-) -> error::Result<impl Future<Item = (), Error = ()>>
-	where F: ServiceFactory, E: Future<Item=(),Error=()> + Send + 'static, R: Read + Seek,
-{
-	let client = new_client::<F>(&config)?;
-	// FIXME #1134 this shouldn't need a mutable config.
-	let select_chain = components::FullComponents::<F>::build_select_chain(&mut config, client.clone())?;
-	let (mut queue, _) = components::FullComponents::<F>::build_import_queue(
-		&mut config,
-		client.clone(),
-		select_chain,
-		None,
-	)?;
 
 	let (exit_send, exit_recv) = std::sync::mpsc::channel();
 	::std::thread::spawn(move || {
-		let _ = exit.wait();
+		let _ = $exit.wait();
 		let _ = exit_send.send(());
 	});
 
-	let mut io_reader_input = IoReader(input);
+	let mut io_reader_input = IoReader($input);
 	let count: u64 = Decode::decode(&mut io_reader_input)
 		.map_err(|e| format!("Error reading file: {}", e))?;
 	info!("Importing {} blocks", count);
@@ -165,11 +133,11 @@ pub fn import_blocks<F, E, R>(
 		if exit_recv.try_recv().is_ok() {
 			break;
 		}
-		match SignedBlock::<F::Block>::decode(&mut io_reader_input) {
+		match SignedBlock::<$block>::decode(&mut io_reader_input) {
 			Ok(signed) => {
 				let (header, extrinsics) = signed.block.deconstruct();
 				let hash = header.hash();
-				let block  = message::BlockData::<F::Block> {
+				let block  = message::BlockData::<$block> {
 					hash,
 					justification: signed.justification,
 					header: Some(header),
@@ -178,8 +146,8 @@ pub fn import_blocks<F, E, R>(
 					message_queue: None
 				};
 				// import queue handles verification and importing it into the client
-				queue.import_blocks(BlockOrigin::File, vec![
-					IncomingBlock::<F::Block> {
+				$queue.import_blocks(BlockOrigin::File, vec![
+					IncomingBlock::<$block> {
 						hash: block.hash,
 						header: block.header,
 						body: block.body,
@@ -208,7 +176,7 @@ pub fn import_blocks<F, E, R>(
 
 		let blocks_before = link.imported_blocks;
 		let _ = futures03::future::poll_fn(|cx| {
-			queue.poll_actions(cx, &mut link);
+			$queue.poll_actions(cx, &mut link);
 			std::task::Poll::Pending::<Result<(), ()>>
 		}).compat().poll();
 		if link.has_error {
@@ -226,24 +194,20 @@ pub fn import_blocks<F, E, R>(
 			);
 		}
 		if link.imported_blocks >= count {
-			info!("Imported {} blocks. Best: #{}", block_count, client.info().chain.best_number);
+			info!("Imported {} blocks. Best: #{}", block_count, $client.info().chain.best_number);
 			Ok(Async::Ready(()))
 		} else {
 			Ok(Async::NotReady)
 		}
 	}))
+}}
 }
 
-/// Revert the chain.
-pub fn revert_chain<F>(
-	config: FactoryFullConfiguration<F>,
-	blocks: FactoryBlockNumber<F>
-) -> error::Result<()>
-	where F: ServiceFactory,
-{
-	let client = new_client::<F>(&config)?;
-	let reverted = client.revert(blocks)?;
-	let info = client.info().chain;
+#[macro_export]
+macro_rules! revert_chain {
+($client:ident, $blocks:ident) => {{
+	let reverted = $client.revert($blocks)?;
+	let info = $client.info().chain;
 
 	if reverted.is_zero() {
 		info!("There aren't any non-finalized blocks to revert.");
@@ -251,6 +215,7 @@ pub fn revert_chain<F>(
 		info!("Reverted {} blocks. Best: #{} ({})", reverted, info.best_number, info.best_hash);
 	}
 	Ok(())
+}}
 }
 
 /// Build a chain spec json
diff --git a/core/service/src/chain_spec.rs b/core/service/src/chain_spec.rs
index 1683876c3f86f..8b35b0bac9581 100644
--- a/core/service/src/chain_spec.rs
+++ b/core/service/src/chain_spec.rs
@@ -24,7 +24,7 @@ use serde::{Serialize, Deserialize};
 use primitives::storage::{StorageKey, StorageData};
 use sr_primitives::{BuildStorage, StorageOverlay, ChildrenStorageOverlay};
 use serde_json as json;
-use crate::components::RuntimeGenesis;
+use crate::RuntimeGenesis;
 use network::Multiaddr;
 use tel::TelemetryEndpoints;
 
diff --git a/core/service/src/components.rs b/core/service/src/components.rs
deleted file mode 100644
index a9aa2129f2498..0000000000000
--- a/core/service/src/components.rs
+++ /dev/null
@@ -1,808 +0,0 @@
-// Copyright 2017-2019 Parity Technologies (UK) Ltd.
-// This file is part of Substrate.
-
-// Substrate is free software: you can redistribute it and/or modify
-// it under the terms of the GNU General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-
-// Substrate is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU General Public License for more details.
-
-// You should have received a copy of the GNU General Public License
-// along with Substrate.  If not, see <http://www.gnu.org/licenses/>.
-
-//! Substrate service components.
-
-use std::{sync::Arc, ops::Deref, ops::DerefMut};
-use serde::{Serialize, de::DeserializeOwned};
-use crate::chain_spec::ChainSpec;
-use keystore::KeyStorePtr;
-use client_db;
-use client::{self, Client, runtime_api};
-use crate::{error, Service};
-use consensus_common::{import_queue::ImportQueue, SelectChain};
-use network::{
-	self, OnDemand, FinalityProofProvider, NetworkStateInfo, config::BoxFinalityProofRequestBuilder
-};
-use substrate_executor::{NativeExecutor, NativeExecutionDispatch};
-use transaction_pool::txpool::{self, Options as TransactionPoolOptions, Pool as TransactionPool};
-use sr_primitives::{
-	BuildStorage, traits::{Block as BlockT, Header as HeaderT, ProvideRuntimeApi}, generic::BlockId
-};
-use crate::config::Configuration;
-use primitives::{Blake2Hasher, H256, traits::BareCryptoStorePtr};
-use rpc::{self, system::SystemInfo};
-use futures::{prelude::*, future::Executor};
-use futures03::{FutureExt as _, channel::mpsc, compat::Compat};
-
-// Type aliases.
-// These exist mainly to avoid typing `<F as Factory>::Foo` all over the code.
-
-/// Network service type for `Components`.
-pub type NetworkService<C> = network::NetworkService<
-	ComponentBlock<C>,
-	<<C as Components>::Factory as ServiceFactory>::NetworkProtocol,
-	ComponentExHash<C>
->;
-
-/// Code executor type for a factory.
-pub type CodeExecutor<F> = NativeExecutor<<F as ServiceFactory>::RuntimeDispatch>;
-
-/// Full client backend type for a factory.
-pub type FullBackend<F> = client_db::Backend<<F as ServiceFactory>::Block>;
-
-/// Full client executor type for a factory.
-pub type FullExecutor<F> = client::LocalCallExecutor<
-	client_db::Backend<<F as ServiceFactory>::Block>,
-	CodeExecutor<F>,
->;
-
-/// Light client backend type for a factory.
-pub type LightBackend<F> = client::light::backend::Backend<
-	client_db::light::LightStorage<<F as ServiceFactory>::Block>,
-	network::OnDemand<<F as ServiceFactory>::Block>,
-	Blake2Hasher,
->;
-
-/// Light client executor type for a factory.
-pub type LightExecutor<F> = client::light::call_executor::RemoteOrLocalCallExecutor<
-	<F as ServiceFactory>::Block,
-	client::light::backend::Backend<
-		client_db::light::LightStorage<<F as ServiceFactory>::Block>,
-		network::OnDemand<<F as ServiceFactory>::Block>,
-		Blake2Hasher
-	>,
-	client::light::call_executor::RemoteCallExecutor<
-		client::light::blockchain::Blockchain<
-			client_db::light::LightStorage<<F as ServiceFactory>::Block>,
-			network::OnDemand<<F as ServiceFactory>::Block>
-		>,
-		network::OnDemand<<F as ServiceFactory>::Block>,
-	>,
-	client::LocalCallExecutor<
-		client::light::backend::Backend<
-			client_db::light::LightStorage<<F as ServiceFactory>::Block>,
-			network::OnDemand<<F as ServiceFactory>::Block>,
-			Blake2Hasher
-		>,
-		CodeExecutor<F>
-	>
->;
-
-/// Full client type for a factory.
-pub type FullClient<F> = Client<FullBackend<F>, FullExecutor<F>, <F as ServiceFactory>::Block, <F as ServiceFactory>::RuntimeApi>;
-
-/// Light client type for a factory.
-pub type LightClient<F> = Client<LightBackend<F>, LightExecutor<F>, <F as ServiceFactory>::Block, <F as ServiceFactory>::RuntimeApi>;
-
-/// `ChainSpec` specialization for a factory.
-pub type FactoryChainSpec<F> = ChainSpec<<F as ServiceFactory>::Genesis>;
-
-/// `Genesis` specialization for a factory.
-pub type FactoryGenesis<F> = <F as ServiceFactory>::Genesis;
-
-/// `Block` type for a factory.
-pub type FactoryBlock<F> = <F as ServiceFactory>::Block;
-
-/// `Extrinsic` type for a factory.
-pub type FactoryExtrinsic<F> = <<F as ServiceFactory>::Block as BlockT>::Extrinsic;
-
-/// `Number` type for a factory.
-pub type FactoryBlockNumber<F> = <<FactoryBlock<F> as BlockT>::Header as HeaderT>::Number;
-
-/// Full `Configuration` type for a factory.
-pub type FactoryFullConfiguration<F> = Configuration<<F as ServiceFactory>::Configuration, FactoryGenesis<F>>;
-
-/// Client type for `Components`.
-pub type ComponentClient<C> = Client<
-	<C as Components>::Backend,
-	<C as Components>::Executor,
-	FactoryBlock<<C as Components>::Factory>,
-	<C as Components>::RuntimeApi,
->;
-
-/// A offchain workers storage backend type.
-pub type ComponentOffchainStorage<C> = <
-	<C as Components>::Backend as client::backend::Backend<ComponentBlock<C>, Blake2Hasher>
->::OffchainStorage;
-
-/// Block type for `Components`
-pub type ComponentBlock<C> = <<C as Components>::Factory as ServiceFactory>::Block;
-
-/// Extrinsic hash type for `Components`
-pub type ComponentExHash<C> = <<C as Components>::TransactionPoolApi as txpool::ChainApi>::Hash;
-
-/// Extrinsic type.
-pub type ComponentExtrinsic<C> = <ComponentBlock<C> as BlockT>::Extrinsic;
-
-/// Extrinsic pool API type for `Components`.
-pub type PoolApi<C> = <C as Components>::TransactionPoolApi;
-
-/// A set of traits for the runtime genesis config.
-pub trait RuntimeGenesis: Serialize + DeserializeOwned + BuildStorage {}
-impl<T: Serialize + DeserializeOwned + BuildStorage> RuntimeGenesis for T {}
-
-/// A transport-agnostic handler of the RPC queries.
-pub type RpcHandler = rpc_servers::RpcHandler<rpc::Metadata>;
-
-/// Something that can create and store initial session keys from given seeds.
-pub trait InitialSessionKeys<C: Components> {
-	/// Generate the initial session keys for the given seeds and store them in
-	/// an internal keystore.
-	fn generate_initial_session_keys(
-		client: Arc<ComponentClient<C>>,
-		seeds: Vec<String>,
-	) -> error::Result<()>;
-}
-
-impl<C: Components> InitialSessionKeys<Self> for C where
-	ComponentClient<C>: ProvideRuntimeApi,
-	<ComponentClient<C> as ProvideRuntimeApi>::Api: session::SessionKeys<ComponentBlock<C>>,
-{
-	fn generate_initial_session_keys(
-		client: Arc<ComponentClient<C>>,
-		seeds: Vec<String>,
-	) -> error::Result<()> {
-		session::generate_initial_session_keys(client, seeds).map_err(Into::into)
-	}
-}
-
-/// Something that can start the RPC service.
-pub trait StartRpc<C: Components> {
-	fn start_rpc(
-		client: Arc<ComponentClient<C>>,
-		system_send_back: mpsc::UnboundedSender<rpc::system::Request<ComponentBlock<C>>>,
-		system_info: SystemInfo,
-		task_executor: TaskExecutor,
-		transaction_pool: Arc<TransactionPool<C::TransactionPoolApi>>,
-		rpc_extensions: impl rpc::RpcExtension<rpc::Metadata>,
-		keystore: KeyStorePtr,
-	) -> RpcHandler;
-}
-
-impl<C: Components> StartRpc<C> for C where
-	ComponentClient<C>: ProvideRuntimeApi,
-	<ComponentClient<C> as ProvideRuntimeApi>::Api:
-		runtime_api::Metadata<ComponentBlock<C>> + session::SessionKeys<ComponentBlock<C>>,
-{
-	fn start_rpc(
-		client: Arc<ComponentClient<C>>,
-		system_send_back: mpsc::UnboundedSender<rpc::system::Request<ComponentBlock<C>>>,
-		rpc_system_info: SystemInfo,
-		task_executor: TaskExecutor,
-		transaction_pool: Arc<TransactionPool<C::TransactionPoolApi>>,
-		rpc_extensions: impl rpc::RpcExtension<rpc::Metadata>,
-		keystore: KeyStorePtr,
-	) -> RpcHandler {
-		use rpc::{chain, state, author, system};
-		let subscriptions = rpc::Subscriptions::new(task_executor.clone());
-		let chain = chain::Chain::new(client.clone(), subscriptions.clone());
-		let state = state::State::new(client.clone(), subscriptions.clone());
-		let author = rpc::author::Author::new(
-			client,
-			transaction_pool,
-			subscriptions,
-			keystore,
-		);
-		let system = system::System::new(rpc_system_info, system_send_back);
-
-		rpc_servers::rpc_handler((
-			state::StateApi::to_delegate(state),
-			chain::ChainApi::to_delegate(chain),
-			author::AuthorApi::to_delegate(author),
-			system::SystemApi::to_delegate(system),
-			rpc_extensions,
-		))
-	}
-}
-
-/// Something that can maintain transaction pool on every imported block.
-pub trait MaintainTransactionPool<C: Components> {
-	fn maintain_transaction_pool(
-		id: &BlockId<ComponentBlock<C>>,
-		client: &ComponentClient<C>,
-		transaction_pool: &TransactionPool<C::TransactionPoolApi>,
-	) -> error::Result<()>;
-}
-
-fn maintain_transaction_pool<Api, Backend, Block, Executor, PoolApi>(
-	id: &BlockId<Block>,
-	client: &Client<Backend, Executor, Block, Api>,
-	transaction_pool: &TransactionPool<PoolApi>,
-) -> error::Result<()> where
-	Block: BlockT<Hash = <Blake2Hasher as primitives::Hasher>::Out>,
-	Backend: client::backend::Backend<Block, Blake2Hasher>,
-	Client<Backend, Executor, Block, Api>: ProvideRuntimeApi,
-	<Client<Backend, Executor, Block, Api> as ProvideRuntimeApi>::Api: runtime_api::TaggedTransactionQueue<Block>,
-	Executor: client::CallExecutor<Block, Blake2Hasher>,
-	PoolApi: txpool::ChainApi<Hash = Block::Hash, Block = Block>,
-{
-	// Avoid calling into runtime if there is nothing to prune from the pool anyway.
-	if transaction_pool.status().is_empty() {
-		return Ok(())
-	}
-
-	if let Some(block) = client.block(id)? {
-		let parent_id = BlockId::hash(*block.block.header().parent_hash());
-		let extrinsics = block.block.extrinsics();
-		transaction_pool.prune(id, &parent_id, extrinsics).map_err(|e| format!("{:?}", e))?;
-	}
-
-	Ok(())
-}
-
-impl<C: Components> MaintainTransactionPool<Self> for C where
-	ComponentClient<C>: ProvideRuntimeApi,
-	<ComponentClient<C> as ProvideRuntimeApi>::Api: runtime_api::TaggedTransactionQueue<ComponentBlock<C>>,
-{
-	fn maintain_transaction_pool(
-		id: &BlockId<ComponentBlock<C>>,
-		client: &ComponentClient<C>,
-		transaction_pool: &TransactionPool<C::TransactionPoolApi>,
-	) -> error::Result<()> {
-		maintain_transaction_pool(id, client, transaction_pool)
-	}
-}
-
-pub trait OffchainWorker<C: Components> {
-	fn offchain_workers(
-		number: &FactoryBlockNumber<C::Factory>,
-		offchain: &offchain::OffchainWorkers<
-			ComponentClient<C>,
-			ComponentOffchainStorage<C>,
-			ComponentBlock<C>
-		>,
-		pool: &Arc<TransactionPool<C::TransactionPoolApi>>,
-		network_state: &Arc<dyn NetworkStateInfo + Send + Sync>,
-		is_validator: bool,
-	) -> error::Result<Box<dyn Future<Item = (), Error = ()> + Send>>;
-}
-
-impl<C: Components> OffchainWorker<Self> for C where
-	ComponentClient<C>: ProvideRuntimeApi,
-	<ComponentClient<C> as ProvideRuntimeApi>::Api: offchain::OffchainWorkerApi<ComponentBlock<C>>,
-{
-	fn offchain_workers(
-		number: &FactoryBlockNumber<C::Factory>,
-		offchain: &offchain::OffchainWorkers<
-			ComponentClient<C>,
-			ComponentOffchainStorage<C>,
-			ComponentBlock<C>
-		>,
-		pool: &Arc<TransactionPool<C::TransactionPoolApi>>,
-		network_state: &Arc<dyn NetworkStateInfo + Send + Sync>,
-		is_validator: bool,
-	) -> error::Result<Box<dyn Future<Item = (), Error = ()> + Send>> {
-		let future = offchain.on_block_imported(number, pool, network_state.clone(), is_validator)
-			.map(|()| Ok(()));
-		Ok(Box::new(Compat::new(future)))
-	}
-}
-
-/// The super trait that combines all required traits a `Service` needs to implement.
-pub trait ServiceTrait<C: Components>:
-	Deref<Target = Service<C>>
-	+ Send
-	+ 'static
-	+ StartRpc<C>
-	+ MaintainTransactionPool<C>
-	+ OffchainWorker<C>
-	+ InitialSessionKeys<C>
-{}
-impl<C: Components, T> ServiceTrait<C> for T where
-	T: Deref<Target = Service<C>>
-	+ Send
-	+ 'static
-	+ StartRpc<C>
-	+ MaintainTransactionPool<C>
-	+ OffchainWorker<C>
-	+ InitialSessionKeys<C>
-{}
-
-/// Alias for a an implementation of `futures::future::Executor`.
-pub type TaskExecutor = Arc<dyn Executor<Box<dyn Future<Item = (), Error = ()> + Send>> + Send + Sync>;
-
-/// A collection of types and methods to build a service on top of the substrate service.
-pub trait ServiceFactory: 'static + Sized {
-	/// Block type.
-	type Block: BlockT<Hash=H256>;
-	/// The type that implements the runtime API.
-	type RuntimeApi: Send + Sync;
-	/// Network protocol extensions.
-	type NetworkProtocol: network::specialization::NetworkSpecialization<Self::Block>;
-	/// Chain runtime.
-	type RuntimeDispatch: NativeExecutionDispatch + Send + Sync + 'static;
-	/// Extrinsic pool backend type for the full client.
-	type FullTransactionPoolApi: txpool::ChainApi<Hash = <Self::Block as BlockT>::Hash, Block = Self::Block> + Send + 'static;
-	/// Extrinsic pool backend type for the light client.
-	type LightTransactionPoolApi: txpool::ChainApi<Hash = <Self::Block as BlockT>::Hash, Block = Self::Block> + 'static;
-	/// Genesis configuration for the runtime.
-	type Genesis: RuntimeGenesis;
-	/// Other configuration for service members.
-	type Configuration: Default;
-	/// RPC initialisation.
-	type RpcExtensions: rpc::RpcExtension<rpc::Metadata>;
-	/// Extended full service type.
-	type FullService: ServiceTrait<FullComponents<Self>>;
-	/// Extended light service type.
-	type LightService: ServiceTrait<LightComponents<Self>>;
-	/// ImportQueue for full client
-	type FullImportQueue: ImportQueue<Self::Block> + 'static;
-	/// ImportQueue for light clients
-	type LightImportQueue: ImportQueue<Self::Block> + 'static;
-	/// The Fork Choice Strategy for the chain
-	type SelectChain: SelectChain<Self::Block> + 'static;
-
-	//TODO: replace these with a constructor trait. that TransactionPool implements. (#1242)
-	/// Extrinsic pool constructor for the full client.
-	fn build_full_transaction_pool(config: TransactionPoolOptions, client: Arc<FullClient<Self>>)
-		-> Result<TransactionPool<Self::FullTransactionPoolApi>, error::Error>;
-	/// Extrinsic pool constructor for the light client.
-	fn build_light_transaction_pool(config: TransactionPoolOptions, client: Arc<LightClient<Self>>)
-		-> Result<TransactionPool<Self::LightTransactionPoolApi>, error::Error>;
-
-	/// Build network protocol.
-	fn build_network_protocol(config: &FactoryFullConfiguration<Self>)
-		-> Result<Self::NetworkProtocol, error::Error>;
-
-	/// Build finality proof provider for serving network requests on full node.
-	fn build_finality_proof_provider(
-		client: Arc<FullClient<Self>>
-	) -> Result<Option<Arc<dyn FinalityProofProvider<Self::Block>>>, error::Error>;
-
-	/// Build the Fork Choice algorithm for full client
-	fn build_select_chain(
-		config: &mut FactoryFullConfiguration<Self>,
-		client: Arc<FullClient<Self>>,
-	) -> Result<Self::SelectChain, error::Error>;
-
-	/// Build full service.
-	fn new_full(config: FactoryFullConfiguration<Self>)
-		-> Result<Self::FullService, error::Error>;
-	/// Build light service.
-	fn new_light(config: FactoryFullConfiguration<Self>)
-		-> Result<Self::LightService, error::Error>;
-
-	/// ImportQueue for a full client
-	fn build_full_import_queue(
-		config: &mut FactoryFullConfiguration<Self>,
-		_client: Arc<FullClient<Self>>,
-		_select_chain: Self::SelectChain,
-		_transaction_pool: Option<Arc<TransactionPool<Self::FullTransactionPoolApi>>>,
-	) -> Result<Self::FullImportQueue, error::Error> {
-		if let Some(name) = config.chain_spec.consensus_engine() {
-			match name {
-				_ => Err(format!("Chain Specification defines unknown consensus engine '{}'", name).into())
-			}
-
-		} else {
-			Err("Chain Specification doesn't contain any consensus_engine name".into())
-		}
-	}
-
-	/// ImportQueue for a light client
-	fn build_light_import_queue(
-		config: &mut FactoryFullConfiguration<Self>,
-		_client: Arc<LightClient<Self>>
-	) -> Result<(Self::LightImportQueue, BoxFinalityProofRequestBuilder<Self::Block>), error::Error> {
-		if let Some(name) = config.chain_spec.consensus_engine() {
-			match name {
-				_ => Err(format!("Chain Specification defines unknown consensus engine '{}'", name).into())
-			}
-
-		} else {
-			Err("Chain Specification doesn't contain any consensus_engine name".into())
-		}
-	}
-
-	/// Create custom RPC method handlers for full node.
-	fn build_full_rpc_extensions(
-		client: Arc<FullClient<Self>>,
-		transaction_pool: Arc<TransactionPool<Self::FullTransactionPoolApi>>,
-	) -> Self::RpcExtensions;
-
-	/// Create custom RPC method handlers for light node.
-	fn build_light_rpc_extensions(
-		client: Arc<LightClient<Self>>,
-		transaction_pool: Arc<TransactionPool<Self::LightTransactionPoolApi>>,
-	) -> Self::RpcExtensions;
-}
-
-/// A collection of types and function to generalize over full / light client type.
-pub trait Components: Sized + 'static {
-	/// Associated service factory.
-	type Factory: ServiceFactory;
-	/// Client backend.
-	type Backend: 'static + client::backend::Backend<FactoryBlock<Self::Factory>, Blake2Hasher>;
-	/// Client executor.
-	type Executor: 'static + client::CallExecutor<FactoryBlock<Self::Factory>, Blake2Hasher> + Send + Sync + Clone;
-	/// The type that implements the runtime API.
-	type RuntimeApi: Send + Sync;
-	/// The type that can start all runtime-dependent services.
-	type RuntimeServices: ServiceTrait<Self>;
-	/// The type that can extend the RPC methods.
-	type RpcExtensions: rpc::RpcExtension<rpc::Metadata>;
-	// TODO: Traitify transaction pool and allow people to implement their own. (#1242)
-	/// Extrinsic pool type.
-	type TransactionPoolApi: 'static + txpool::ChainApi<
-		Hash = <FactoryBlock<Self::Factory> as BlockT>::Hash,
-		Block = FactoryBlock<Self::Factory>
-	>;
-	/// Our Import Queue
-	type ImportQueue: ImportQueue<FactoryBlock<Self::Factory>> + 'static;
-	/// The Fork Choice Strategy for the chain
-	type SelectChain: SelectChain<FactoryBlock<Self::Factory>>;
-
-	/// Create client.
-	fn build_client(
-		config: &FactoryFullConfiguration<Self::Factory>,
-		executor: CodeExecutor<Self::Factory>,
-		keystore: Option<BareCryptoStorePtr>,
-	) -> Result<
-		(
-			Arc<ComponentClient<Self>>,
-			Option<Arc<OnDemand<FactoryBlock<Self::Factory>>>>
-		),
-		error::Error
-	>;
-
-	/// Create extrinsic pool.
-	fn build_transaction_pool(config: TransactionPoolOptions, client: Arc<ComponentClient<Self>>)
-		-> Result<TransactionPool<Self::TransactionPoolApi>, error::Error>;
-
-	/// Build the queue that imports blocks from the network, and optionally a way for the network
-	/// to build requests for proofs of finality.
-	fn build_import_queue(
-		config: &mut FactoryFullConfiguration<Self::Factory>,
-		client: Arc<ComponentClient<Self>>,
-		select_chain: Option<Self::SelectChain>,
-		_transaction_pool: Option<Arc<TransactionPool<Self::TransactionPoolApi>>>,
-	) -> Result<(Self::ImportQueue, Option<BoxFinalityProofRequestBuilder<FactoryBlock<Self::Factory>>>), error::Error>;
-
-	/// Finality proof provider for serving network requests.
-	fn build_finality_proof_provider(
-		client: Arc<ComponentClient<Self>>
-	) -> Result<Option<Arc<dyn FinalityProofProvider<<Self::Factory as ServiceFactory>::Block>>>, error::Error>;
-
-	/// Build fork choice selector
-	fn build_select_chain(
-		config: &mut FactoryFullConfiguration<Self::Factory>,
-		client: Arc<ComponentClient<Self>>
-	) -> Result<Option<Self::SelectChain>, error::Error>;
-
-	/// Build RPC extensions
-	fn build_rpc_extensions(
-		client: Arc<ComponentClient<Self>>,
-		transaction_pool: Arc<TransactionPool<Self::TransactionPoolApi>>,
-	) -> Self::RpcExtensions;
-}
-
-/// A struct that implement `Components` for the full client.
-pub struct FullComponents<Factory: ServiceFactory> {
-	service: Service<FullComponents<Factory>>,
-}
-
-impl<Factory: ServiceFactory> FullComponents<Factory> {
-	/// Create new `FullComponents`
-	pub fn new(
-		config: FactoryFullConfiguration<Factory>
-	) -> Result<Self, error::Error> {
-		Ok(
-			Self {
-				service: Service::new(config)?,
-			}
-		)
-	}
-}
-
-impl<Factory: ServiceFactory> Deref for FullComponents<Factory> {
-	type Target = Service<Self>;
-
-	fn deref(&self) -> &Self::Target {
-		&self.service
-	}
-}
-
-impl<Factory: ServiceFactory> DerefMut for FullComponents<Factory> {
-	fn deref_mut(&mut self) -> &mut Service<Self> {
-		&mut self.service
-	}
-}
-
-impl<Factory: ServiceFactory> Future for FullComponents<Factory> {
-	type Item = ();
-	type Error = super::Error;
-
-	fn poll(&mut self) -> Poll<Self::Item, Self::Error> {
-		self.service.poll()
-	}
-}
-
-impl<Factory: ServiceFactory> Executor<Box<dyn Future<Item = (), Error = ()> + Send>>
-for FullComponents<Factory> {
-	fn execute(
-		&self,
-		future: Box<dyn Future<Item = (), Error = ()> + Send>
-	) -> Result<(), futures::future::ExecuteError<Box<dyn Future<Item = (), Error = ()> + Send>>> {
-		self.service.execute(future)
-	}
-}
-
-impl<Factory: ServiceFactory> Components for FullComponents<Factory> {
-	type Factory = Factory;
-	type Executor = FullExecutor<Factory>;
-	type Backend = FullBackend<Factory>;
-	type TransactionPoolApi = <Factory as ServiceFactory>::FullTransactionPoolApi;
-	type ImportQueue = Factory::FullImportQueue;
-	type RuntimeApi = Factory::RuntimeApi;
-	type RuntimeServices = Factory::FullService;
-	type RpcExtensions = Factory::RpcExtensions;
-	type SelectChain = Factory::SelectChain;
-
-	fn build_client(
-		config: &FactoryFullConfiguration<Factory>,
-		executor: CodeExecutor<Self::Factory>,
-		keystore: Option<BareCryptoStorePtr>,
-	) -> Result<
-			(Arc<ComponentClient<Self>>, Option<Arc<OnDemand<FactoryBlock<Self::Factory>>>>),
-			error::Error,
-		>
-	{
-		let db_settings = client_db::DatabaseSettings {
-			cache_size: config.database_cache_size.map(|u| u as usize),
-			state_cache_size: config.state_cache_size,
-			state_cache_child_ratio:
-				config.state_cache_child_ratio.map(|v| (v, 100)),
-			path: config.database_path.clone(),
-			pruning: config.pruning.clone(),
-		};
-
-		Ok((
-			Arc::new(
-				client_db::new_client(
-					db_settings,
-					executor,
-					&config.chain_spec,
-					config.execution_strategies.clone(),
-					keystore,
-				)?
-			),
-			None,
-		))
-	}
-
-	fn build_transaction_pool(
-		config: TransactionPoolOptions,
-		client: Arc<ComponentClient<Self>>
-	) -> Result<TransactionPool<Self::TransactionPoolApi>, error::Error> {
-		Factory::build_full_transaction_pool(config, client)
-	}
-
-	fn build_import_queue(
-		config: &mut FactoryFullConfiguration<Self::Factory>,
-		client: Arc<ComponentClient<Self>>,
-		select_chain: Option<Self::SelectChain>,
-		transaction_pool: Option<Arc<TransactionPool<Self::TransactionPoolApi>>>,
-	) -> Result<(Self::ImportQueue, Option<BoxFinalityProofRequestBuilder<FactoryBlock<Self::Factory>>>), error::Error> {
-		let select_chain = select_chain
-			.ok_or(error::Error::SelectChainRequired)?;
-		Factory::build_full_import_queue(config, client, select_chain, transaction_pool)
-			.map(|queue| (queue, None))
-	}
-
-	fn build_select_chain(
-		config: &mut FactoryFullConfiguration<Self::Factory>,
-		client: Arc<ComponentClient<Self>>
-	) -> Result<Option<Self::SelectChain>, error::Error> {
-		Self::Factory::build_select_chain(config, client).map(Some)
-	}
-
-	fn build_finality_proof_provider(
-		client: Arc<ComponentClient<Self>>
-	) -> Result<Option<Arc<dyn FinalityProofProvider<<Self::Factory as ServiceFactory>::Block>>>, error::Error> {
-		Factory::build_finality_proof_provider(client)
-	}
-
-	fn build_rpc_extensions(
-		client: Arc<ComponentClient<Self>>,
-		transaction_pool: Arc<TransactionPool<Self::TransactionPoolApi>>,
-	) -> Self::RpcExtensions {
-		Factory::build_full_rpc_extensions(client, transaction_pool)
-	}
-}
-
-/// A struct that implement `Components` for the light client.
-pub struct LightComponents<Factory: ServiceFactory> {
-	service: Service<LightComponents<Factory>>,
-}
-
-impl<Factory: ServiceFactory> LightComponents<Factory> {
-	/// Create new `LightComponents`
-	pub fn new(
-		config: FactoryFullConfiguration<Factory>,
-	) -> Result<Self, error::Error> {
-		Ok(
-			Self {
-				service: Service::new(config)?,
-			}
-		)
-	}
-}
-
-impl<Factory: ServiceFactory> Deref for LightComponents<Factory> {
-	type Target = Service<Self>;
-
-	fn deref(&self) -> &Self::Target {
-		&self.service
-	}
-}
-
-impl<Factory: ServiceFactory> DerefMut for LightComponents<Factory> {
-	fn deref_mut(&mut self) -> &mut Self::Target {
-		&mut self.service
-	}
-}
-
-impl<Factory: ServiceFactory> Future for LightComponents<Factory> {
-	type Item = ();
-	type Error = super::Error;
-
-	fn poll(&mut self) -> Poll<Self::Item, Self::Error> {
-		self.service.poll()
-	}
-}
-
-impl<Factory: ServiceFactory> Executor<Box<dyn Future<Item = (), Error = ()> + Send>>
-for LightComponents<Factory> {
-	fn execute(
-		&self,
-		future: Box<dyn Future<Item = (), Error = ()> + Send>
-	) -> Result<(), futures::future::ExecuteError<Box<dyn Future<Item = (), Error = ()> + Send>>> {
-		self.service.execute(future)
-	}
-}
-
-impl<Factory: ServiceFactory> Components for LightComponents<Factory> {
-	type Factory = Factory;
-	type Executor = LightExecutor<Factory>;
-	type Backend = LightBackend<Factory>;
-	type TransactionPoolApi = <Factory as ServiceFactory>::LightTransactionPoolApi;
-	type ImportQueue = <Factory as ServiceFactory>::LightImportQueue;
-	type RuntimeApi = Factory::RuntimeApi;
-	type RuntimeServices = Factory::LightService;
-	type RpcExtensions = Factory::RpcExtensions;
-	type SelectChain = Factory::SelectChain;
-
-	fn build_client(
-		config: &FactoryFullConfiguration<Factory>,
-		executor: CodeExecutor<Self::Factory>,
-		_: Option<BareCryptoStorePtr>,
-	)
-		-> Result<
-			(
-				Arc<ComponentClient<Self>>,
-				Option<Arc<OnDemand<FactoryBlock<Self::Factory>>>>
-			), error::Error>
-	{
-		let db_settings = client_db::DatabaseSettings {
-			cache_size: None,
-			state_cache_size: config.state_cache_size,
-			state_cache_child_ratio:
-				config.state_cache_child_ratio.map(|v| (v, 100)),
-			path: config.database_path.clone(),
-			pruning: config.pruning.clone(),
-		};
-
-		let db_storage = client_db::light::LightStorage::new(db_settings)?;
-		let light_blockchain = client::light::new_light_blockchain(db_storage);
-		let fetch_checker = Arc::new(
-			client::light::new_fetch_checker(light_blockchain.clone(), executor.clone())
-		);
-		let fetcher = Arc::new(network::OnDemand::new(fetch_checker));
-		let client_backend = client::light::new_light_backend(light_blockchain, fetcher.clone());
-		let client = client::light::new_light(client_backend, fetcher.clone(), &config.chain_spec, executor)?;
-		Ok((Arc::new(client), Some(fetcher)))
-	}
-
-	fn build_transaction_pool(config: TransactionPoolOptions, client: Arc<ComponentClient<Self>>)
-		-> Result<TransactionPool<Self::TransactionPoolApi>, error::Error>
-	{
-		Factory::build_light_transaction_pool(config, client)
-	}
-
-	fn build_import_queue(
-		config: &mut FactoryFullConfiguration<Self::Factory>,
-		client: Arc<ComponentClient<Self>>,
-		_select_chain: Option<Self::SelectChain>,
-		_transaction_pool: Option<Arc<TransactionPool<Self::TransactionPoolApi>>>,
-	) -> Result<(Self::ImportQueue, Option<BoxFinalityProofRequestBuilder<FactoryBlock<Self::Factory>>>), error::Error> {
-		Factory::build_light_import_queue(config, client)
-			.map(|(queue, builder)| (queue, Some(builder)))
-	}
-
-	fn build_finality_proof_provider(
-		_client: Arc<ComponentClient<Self>>
-	) -> Result<Option<Arc<dyn FinalityProofProvider<<Self::Factory as ServiceFactory>::Block>>>, error::Error> {
-		Ok(None)
-	}
-
-	fn build_select_chain(
-		_config: &mut FactoryFullConfiguration<Self::Factory>,
-		_client: Arc<ComponentClient<Self>>
-	) -> Result<Option<Self::SelectChain>, error::Error> {
-		Ok(None)
-	}
-
-	fn build_rpc_extensions(
-		client: Arc<ComponentClient<Self>>,
-		transaction_pool: Arc<TransactionPool<Self::TransactionPoolApi>>,
-	) -> Self::RpcExtensions {
-		Factory::build_light_rpc_extensions(client, transaction_pool)
-	}
-}
-
-#[cfg(test)]
-mod tests {
-	use super::*;
-	use consensus_common::BlockOrigin;
-	use substrate_test_runtime_client::{prelude::*, runtime::Transfer};
-
-	#[test]
-	fn should_remove_transactions_from_the_pool() {
-		let (client, longest_chain) = TestClientBuilder::new().build_with_longest_chain();
-		let client = Arc::new(client);
-		let pool = TransactionPool::new(Default::default(), ::transaction_pool::ChainApi::new(client.clone()));
-		let transaction = Transfer {
-			amount: 5,
-			nonce: 0,
-			from: AccountKeyring::Alice.into(),
-			to: Default::default(),
-		}.into_signed_tx();
-		let best = longest_chain.best_chain().unwrap();
-
-		// store the transaction in the pool
-		pool.submit_one(&BlockId::hash(best.hash()), transaction.clone()).unwrap();
-
-		// import the block
-		let mut builder = client.new_block(Default::default()).unwrap();
-		builder.push(transaction.clone()).unwrap();
-		let block = builder.bake().unwrap();
-		let id = BlockId::hash(block.header().hash());
-		client.import(BlockOrigin::Own, block).unwrap();
-
-		// fire notification - this should clean up the queue
-		assert_eq!(pool.status().ready, 1);
-		maintain_transaction_pool(
-			&id,
-			&client,
-			&pool,
-		).unwrap();
-
-		// then
-		assert_eq!(pool.status().ready, 0);
-		assert_eq!(pool.status().future, 0);
-	}
-}
diff --git a/core/service/src/lib.rs b/core/service/src/lib.rs
index 33a42e87fe04a..1362e86c2148d 100644
--- a/core/service/src/lib.rs
+++ b/core/service/src/lib.rs
@@ -19,51 +19,43 @@
 
 #![warn(missing_docs)]
 
-mod components;
 mod chain_spec;
 pub mod config;
+#[macro_use]
 pub mod chain_ops;
 pub mod error;
 
 use std::io;
+use std::marker::PhantomData;
 use std::net::SocketAddr;
 use std::collections::HashMap;
 use std::sync::atomic::{AtomicBool, Ordering};
 use std::time::{Duration, Instant};
+use serde::{Serialize, de::DeserializeOwned};
 use futures::sync::mpsc;
 use parking_lot::Mutex;
 
-use client::{BlockchainEvents, backend::Backend, runtime_api::BlockT};
+use client::{runtime_api::BlockT, Client};
 use exit_future::Signal;
 use futures::prelude::*;
 use futures03::stream::{StreamExt as _, TryStreamExt as _};
-use keystore::Store as Keystore;
-use network::{NetworkState, NetworkStateInfo};
-use log::{log, info, warn, debug, error, Level};
+use network::{NetworkService, NetworkState, specialization::NetworkSpecialization};
+use log::{log, warn, debug, error, Level};
 use codec::{Encode, Decode};
+use primitives::{Blake2Hasher, H256};
+use sr_primitives::BuildStorage;
 use sr_primitives::generic::BlockId;
-use sr_primitives::traits::{Header, NumberFor, SaturatedConversion};
-use substrate_executor::NativeExecutor;
-use sysinfo::{get_current_pid, ProcessExt, System, SystemExt};
-use tel::{telemetry, SUBSTRATE_INFO};
+use sr_primitives::traits::NumberFor;
 
 pub use self::error::Error;
+pub use self::builder::{ServiceBuilder, ServiceBuilderExport, ServiceBuilderImport, ServiceBuilderRevert};
 pub use config::{Configuration, Roles, PruningMode};
 pub use chain_spec::{ChainSpec, Properties};
 pub use transaction_pool::txpool::{
 	self, Pool as TransactionPool, Options as TransactionPoolOptions, ChainApi, IntoPoolError
 };
 pub use client::FinalityNotifications;
-
-pub use components::{
-	ServiceFactory, FullBackend, FullExecutor, LightBackend,
-	LightExecutor, Components, PoolApi, ComponentClient, ComponentOffchainStorage,
-	ComponentBlock, FullClient, LightClient, FullComponents, LightComponents,
-	CodeExecutor, NetworkService, FactoryChainSpec, FactoryBlock,
-	FactoryFullConfiguration, RuntimeGenesis, FactoryGenesis,
-	ComponentExHash, ComponentExtrinsic, FactoryExtrinsic, InitialSessionKeys,
-};
-use components::{StartRpc, MaintainTransactionPool, OffchainWorker};
+pub use rpc::Metadata as RpcMetadata;
 #[doc(hidden)]
 pub use std::{ops::Deref, result::Result, sync::Arc};
 #[doc(hidden)]
@@ -74,15 +66,15 @@ pub use futures::future::Executor;
 const DEFAULT_PROTOCOL_ID: &str = "sup";
 
 /// Substrate service.
-pub struct Service<Components: components::Components> {
-	client: Arc<ComponentClient<Components>>,
-	select_chain: Option<Components::SelectChain>,
-	network: Arc<components::NetworkService<Components>>,
+pub struct NewService<TCfg, TBl, TCl, TSc, TNetStatus, TNet, TTxPool, TOc> {
+	client: Arc<TCl>,
+	select_chain: Option<TSc>,
+	network: Arc<TNet>,
 	/// Sinks to propagate network status updates.
 	network_status_sinks: Arc<Mutex<Vec<mpsc::UnboundedSender<(
-		NetworkStatus<ComponentBlock<Components>>, NetworkState
+		TNetStatus, NetworkState
 	)>>>>,
-	transaction_pool: Arc<TransactionPool<Components::TransactionPoolApi>>,
+	transaction_pool: Arc<TTxPool>,
 	/// A future that resolves when the service has exited, this is useful to
 	/// make sure any internally spawned futures stop when the service does.
 	exit: exit_future::Exit,
@@ -100,31 +92,22 @@ pub struct Service<Components: components::Components> {
 	/// The elements must then be polled manually.
 	to_poll: Vec<Box<dyn Future<Item = (), Error = ()> + Send>>,
 	/// Configuration of this Service
-	config: FactoryFullConfiguration<Components::Factory>,
-	rpc_handlers: components::RpcHandler,
+	config: TCfg,
+	rpc_handlers: rpc_servers::RpcHandler<rpc::Metadata>,
 	_rpc: Box<dyn std::any::Any + Send + Sync>,
 	_telemetry: Option<tel::Telemetry>,
 	_telemetry_on_connect_sinks: Arc<Mutex<Vec<mpsc::UnboundedSender<()>>>>,
-	_offchain_workers: Option<Arc<offchain::OffchainWorkers<
-		ComponentClient<Components>,
-		ComponentOffchainStorage<Components>,
-		ComponentBlock<Components>>
-	>>,
+	_offchain_workers: Option<Arc<TOc>>,
 	keystore: keystore::KeyStorePtr,
+	marker: PhantomData<TBl>,
 }
 
-/// Creates bare client without any networking.
-pub fn new_client<Factory: components::ServiceFactory>(
-	config: &FactoryFullConfiguration<Factory>,
-) -> Result<Arc<ComponentClient<components::FullComponents<Factory>>>, error::Error> {
-	let executor = NativeExecutor::new(config.default_heap_pages);
-
-	components::FullComponents::<Factory>::build_client(
-		config,
-		executor,
-		None,
-	).map(|r| r.0)
-}
+/// A set of traits for the runtime genesis config.
+pub trait RuntimeGenesis: Serialize + DeserializeOwned + BuildStorage {}
+impl<T: Serialize + DeserializeOwned + BuildStorage> RuntimeGenesis for T {}
+
+/// Alias for a an implementation of `futures::future::Executor`.
+pub type TaskExecutor = Arc<dyn Executor<Box<dyn Future<Item = (), Error = ()> + Send>> + Send + Sync>;
 
 /// An handle for spawning tasks in the service.
 #[derive(Clone)]
@@ -146,59 +129,38 @@ impl Executor<Box<dyn Future<Item = (), Error = ()> + Send>> for SpawnTaskHandle
 	}
 }
 
-/// Stream of events for connection established to a telemetry server.
-pub type TelemetryOnConnectNotifications = mpsc::UnboundedReceiver<()>;
-
-/// Used to hook on telemetry connection established events.
-pub struct TelemetryOnConnect {
-	/// Event stream.
-	pub telemetry_connection_sinks: TelemetryOnConnectNotifications,
-}
-
-impl<Components: components::Components> Service<Components> {
-	/// Creates a new service.
-	pub fn new(
-		mut config: FactoryFullConfiguration<Components::Factory>,
-	) -> Result<Self, error::Error> {
+macro_rules! new_impl {
+	(
+		$block:ty,
+		$config:ident,
+		$build_components:expr,
+		$maintain_transaction_pool:expr,
+		$offchain_workers:expr,
+		$start_rpc:expr,
+	) => {{
 		let (signal, exit) = exit_future::signal();
 
 		// List of asynchronous tasks to spawn. We collect them, then spawn them all at once.
 		let (to_spawn_tx, to_spawn_rx) =
 			mpsc::unbounded::<Box<dyn Future<Item = (), Error = ()> + Send>>();
 
-		// Create client
-		let executor = NativeExecutor::new(config.default_heap_pages);
-
-		let keystore = Keystore::open(config.keystore_path.clone(), config.keystore_password.clone())?;
-
-		let (client, on_demand) = Components::build_client(&config, executor, Some(keystore.clone()))?;
-		let select_chain = Components::build_select_chain(&mut config, client.clone())?;
-
-		let transaction_pool = Arc::new(
-			Components::build_transaction_pool(config.transaction_pool.clone(), client.clone())?
-		);
-		let transaction_pool_adapter = Arc::new(TransactionPoolAdapter {
-			imports_external_transactions: !config.roles.is_light(),
-			pool: transaction_pool.clone(),
-			client: client.clone(),
-		});
-
-		let (import_queue, finality_proof_request_builder) = Components::build_import_queue(
-			&mut config,
-			client.clone(),
-			select_chain.clone(),
-			Some(transaction_pool.clone()),
-		)?;
+		// Create all the components.
+		let (
+			client,
+			on_demand,
+			keystore,
+			select_chain,
+			import_queue,
+			finality_proof_request_builder,
+			finality_proof_provider,
+			network_protocol,
+			transaction_pool,
+			rpc_extensions
+		) = $build_components(&mut $config)?;
 		let import_queue = Box::new(import_queue);
-		let finality_proof_provider = Components::build_finality_proof_provider(client.clone())?;
 		let chain_info = client.info().chain;
 
-		Components::RuntimeServices::generate_initial_session_keys(
-			client.clone(),
-			config.dev_key_seed.clone().map(|s| vec![s]).unwrap_or_default(),
-		)?;
-
-		let version = config.full_version();
+		let version = $config.full_version();
 		info!("Highest known block at #{}", chain_info.best_number);
 		telemetry!(
 			SUBSTRATE_INFO;
@@ -207,10 +169,14 @@ impl<Components: components::Components> Service<Components> {
 			"best" => ?chain_info.best_hash
 		);
 
-		let network_protocol = <Components::Factory>::build_network_protocol(&config)?;
+		let transaction_pool_adapter = Arc::new(TransactionPoolAdapter {
+			imports_external_transactions: !$config.roles.is_light(),
+			pool: transaction_pool.clone(),
+			client: client.clone(),
+		});
 
 		let protocol_id = {
-			let protocol_id_full = match config.chain_spec.protocol_id() {
+			let protocol_id_full = match $config.chain_spec.protocol_id() {
 				Some(pid) => pid,
 				None => {
 					warn!("Using default protocol ID {:?} because none is configured in the \
@@ -223,8 +189,8 @@ impl<Components: components::Components> Service<Components> {
 		};
 
 		let network_params = network::config::Params {
-			roles: config.roles,
-			network_config: config.network.clone(),
+			roles: $config.roles,
+			network_config: $config.network.clone(),
 			chain: client.clone(),
 			finality_proof_provider,
 			finality_proof_request_builder,
@@ -242,7 +208,7 @@ impl<Components: components::Components> Service<Components> {
 
 		#[allow(deprecated)]
 		let offchain_storage = client.backend().offchain_storage();
-		let offchain_workers = match (config.offchain_worker, offchain_storage) {
+		let offchain_workers = match ($config.offchain_worker, offchain_storage) {
 			(true, Some(db)) => {
 				Some(Arc::new(offchain::OffchainWorkers::new(client.clone(), db)))
 			},
@@ -260,23 +226,25 @@ impl<Components: components::Components> Service<Components> {
 			let offchain = offchain_workers.as_ref().map(Arc::downgrade);
 			let to_spawn_tx_ = to_spawn_tx.clone();
 			let network_state_info: Arc<dyn NetworkStateInfo + Send + Sync> = network.clone();
-			let is_validator = config.roles.is_authority();
+			let is_validator = $config.roles.is_authority();
 
 			let events = client.import_notification_stream()
 				.map(|v| Ok::<_, ()>(v)).compat()
 				.for_each(move |notification| {
 					let number = *notification.header.number();
+					let txpool = txpool.upgrade();
 
-					if let (Some(txpool), Some(client)) = (txpool.upgrade(), wclient.upgrade()) {
-						Components::RuntimeServices::maintain_transaction_pool(
+					if let (Some(txpool), Some(client)) = (txpool.as_ref(), wclient.upgrade()) {
+						$maintain_transaction_pool(
 							&BlockId::hash(notification.hash),
 							&*client,
 							&*txpool,
 						).map_err(|e| warn!("Pool error processing new block: {:?}", e))?;
 					}
 
-					if let (Some(txpool), Some(offchain)) = (txpool.upgrade(), offchain.as_ref().and_then(|o| o.upgrade())) {
-						let future = Components::RuntimeServices::offchain_workers(
+					let offchain = offchain.as_ref().and_then(|o| o.upgrade());
+					if let (Some(txpool), Some(offchain)) = (txpool, offchain) {
+						let future = $offchain_workers(
 							&number,
 							&offchain,
 							&txpool,
@@ -321,7 +289,7 @@ impl<Components: components::Components> Service<Components> {
 		let client_ = client.clone();
 		let mut sys = System::new();
 		let self_pid = get_current_pid().ok();
-		let (netstat_tx, netstat_rx) = mpsc::unbounded::<(NetworkStatus<ComponentBlock<Components>>, NetworkState)>();
+		let (netstat_tx, netstat_rx) = mpsc::unbounded::<(NetworkStatus<_>, NetworkState)>();
 		network_status_sinks.lock().push(netstat_tx);
 		let tel_task = netstat_rx.for_each(move |(net_status, network_state)| {
 			let info = client_.info();
@@ -374,23 +342,23 @@ impl<Components: components::Components> Service<Components> {
 		let (system_rpc_tx, system_rpc_rx) = futures03::channel::mpsc::unbounded();
 		let gen_handler = || {
 			let system_info = rpc::system::SystemInfo {
-				chain_name: config.chain_spec.name().into(),
-				impl_name: config.impl_name.into(),
-				impl_version: config.impl_version.into(),
-				properties: config.chain_spec.properties(),
+				chain_name: $config.chain_spec.name().into(),
+				impl_name: $config.impl_name.into(),
+				impl_version: $config.impl_version.into(),
+				properties: $config.chain_spec.properties(),
 			};
-			Components::RuntimeServices::start_rpc(
+			$start_rpc(
 				client.clone(),
 				system_rpc_tx.clone(),
 				system_info.clone(),
 				Arc::new(SpawnTaskHandle { sender: to_spawn_tx.clone() }),
 				transaction_pool.clone(),
-				Components::build_rpc_extensions(client.clone(), transaction_pool.clone()),
+				rpc_extensions.clone(),
 				keystore.clone(),
 			)
 		};
 		let rpc_handlers = gen_handler();
-		let rpc = start_rpc_servers(&config, gen_handler)?;
+		let rpc = start_rpc_servers(&$config, gen_handler)?;
 
 		let _ = to_spawn_tx.unbounded_send(Box::new(build_network_future(
 			network_mut,
@@ -406,17 +374,17 @@ impl<Components: components::Components> Service<Components> {
 		let telemetry_connection_sinks: Arc<Mutex<Vec<mpsc::UnboundedSender<()>>>> = Default::default();
 
 		// Telemetry
-		let telemetry = config.telemetry_endpoints.clone().map(|endpoints| {
-			let is_authority = config.roles.is_authority();
+		let telemetry = $config.telemetry_endpoints.clone().map(|endpoints| {
+			let is_authority = $config.roles.is_authority();
 			let network_id = network.local_peer_id().to_base58();
-			let name = config.name.clone();
-			let impl_name = config.impl_name.to_owned();
+			let name = $config.name.clone();
+			let impl_name = $config.impl_name.to_owned();
 			let version = version.clone();
-			let chain_name = config.chain_spec.name().to_owned();
+			let chain_name = $config.chain_spec.name().to_owned();
 			let telemetry_connection_sinks_ = telemetry_connection_sinks.clone();
 			let telemetry = tel::init_telemetry(tel::TelemetryConfig {
 				endpoints,
-				wasm_external_transport: config.telemetry_external_transport.take(),
+				wasm_external_transport: $config.telemetry_external_transport.take(),
 			});
 			let future = telemetry.clone()
 				.map(|ev| Ok::<_, ()>(ev))
@@ -446,7 +414,7 @@ impl<Components: components::Components> Service<Components> {
 			telemetry
 		});
 
-		Ok(Service {
+		Ok(NewService {
 			client,
 			network,
 			network_status_sinks,
@@ -458,56 +426,145 @@ impl<Components: components::Components> Service<Components> {
 			to_spawn_tx,
 			to_spawn_rx,
 			to_poll: Vec::new(),
-			config,
+			$config,
 			rpc_handlers,
 			_rpc: rpc,
 			_telemetry: telemetry,
 			_offchain_workers: offchain_workers,
 			_telemetry_on_connect_sinks: telemetry_connection_sinks.clone(),
 			keystore,
+			marker: PhantomData::<$block>,
 		})
-	}
+	}}
+}
+
+mod builder;
+
+/// Abstraction over a Substrate service.
+pub trait AbstractService: 'static + Future<Item = (), Error = Error> +
+	Executor<Box<dyn Future<Item = (), Error = ()> + Send>> + Send {
+	/// Type of block of this chain.
+	type Block: BlockT<Hash = H256>;
+	/// Backend storage for the client.
+	type Backend: 'static + client::backend::Backend<Self::Block, Blake2Hasher>;
+	/// How to execute calls towards the runtime.
+	type CallExecutor: 'static + client::CallExecutor<Self::Block, Blake2Hasher> + Send + Sync + Clone;
+	/// API that the runtime provides.
+	type RuntimeApi: Send + Sync;
+	/// Configuration struct of the service.
+	type Config;
+	/// Chain selection algorithm.
+	type SelectChain: consensus_common::SelectChain<Self::Block>;
+	/// API of the transaction pool.
+	type TransactionPoolApi: ChainApi<Block = Self::Block>;
+	/// Network specialization.
+	type NetworkSpecialization: NetworkSpecialization<Self::Block>;
+
+	/// Get event stream for telemetry connection established events.
+	fn telemetry_on_connect_stream(&self) -> mpsc::UnboundedReceiver<()>;
+
+	/// Returns the configuration passed on construction.
+	fn config(&self) -> &Self::Config;
+
+	/// Returns the configuration passed on construction.
+	fn config_mut(&mut self) -> &mut Self::Config;
+
+	/// return a shared instance of Telemetry (if enabled)
+	fn telemetry(&self) -> Option<tel::Telemetry>;
+
+	/// Spawns a task in the background that runs the future passed as parameter.
+	fn spawn_task(&self, task: impl Future<Item = (), Error = ()> + Send + 'static);
+
+	/// Spawns a task in the background that runs the future passed as
+	/// parameter. The given task is considered essential, i.e. if it errors we
+	/// trigger a service exit.
+	fn spawn_essential_task(&self, task: impl Future<Item = (), Error = ()> + Send + 'static);
+
+	/// Returns a handle for spawning tasks.
+	fn spawn_task_handle(&self) -> SpawnTaskHandle;
+
+	/// Returns the keystore that stores keys.
+	fn keystore(&self) -> keystore::KeyStorePtr;
+
+	/// Starts an RPC query.
+	///
+	/// The query is passed as a string and must be a JSON text similar to what an HTTP client
+	/// would for example send.
+	///
+	/// Returns a `Future` that contains the optional response.
+	///
+	/// If the request subscribes you to events, the `Sender` in the `RpcSession` object is used to
+	/// send back spontaneous events.
+	fn rpc_query(&self, mem: &RpcSession, request: &str) -> Box<dyn Future<Item = Option<String>, Error = ()> + Send>;
+
+	/// Get shared client instance.
+	fn client(&self) -> Arc<client::Client<Self::Backend, Self::CallExecutor, Self::Block, Self::RuntimeApi>>;
+
+	/// Get clone of select chain.
+	fn select_chain(&self) -> Option<Self::SelectChain>;
+
+	/// Get shared network instance.
+	fn network(&self) -> Arc<NetworkService<Self::Block, Self::NetworkSpecialization, H256>>;
 
-	/// Returns a reference to the config passed at initialization.
-	pub fn config(&self) -> &FactoryFullConfiguration<Components::Factory> {
+	/// Returns a receiver that periodically receives a status of the network.
+	fn network_status(&self) -> mpsc::UnboundedReceiver<(NetworkStatus<Self::Block>, NetworkState)>;
+
+	/// Get shared transaction pool instance.
+	fn transaction_pool(&self) -> Arc<TransactionPool<Self::TransactionPoolApi>>;
+
+	/// Get a handle to a future that will resolve on exit.
+	fn on_exit(&self) -> ::exit_future::Exit;
+}
+
+impl<TCfg, TBl, TBackend, TExec, TRtApi, TSc, TNetSpec, TExPoolApi, TOc> AbstractService for
+	NewService<TCfg, TBl, Client<TBackend, TExec, TBl, TRtApi>, TSc, NetworkStatus<TBl>,
+		NetworkService<TBl, TNetSpec, H256>, TransactionPool<TExPoolApi>, TOc>
+where TCfg: 'static + Send,
+	TBl: BlockT<Hash = H256>,
+	TBackend: 'static + client::backend::Backend<TBl, Blake2Hasher>,
+	TExec: 'static + client::CallExecutor<TBl, Blake2Hasher> + Send + Sync + Clone,
+	TRtApi: 'static + Send + Sync,
+	TSc: consensus_common::SelectChain<TBl> + 'static + Clone + Send,
+	TExPoolApi: 'static + ChainApi<Block = TBl>,
+	TOc: 'static + Send + Sync,
+	TNetSpec: NetworkSpecialization<TBl>,
+{
+	type Block = TBl;
+	type Backend = TBackend;
+	type CallExecutor = TExec;
+	type RuntimeApi = TRtApi;
+	type Config = TCfg;
+	type SelectChain = TSc;
+	type TransactionPoolApi = TExPoolApi;
+	type NetworkSpecialization = TNetSpec;
+
+	fn config(&self) -> &Self::Config {
 		&self.config
 	}
 
-	/// Returns a reference to the config passed at initialization.
-	///
-	/// > **Note**: This method is currently necessary because we extract some elements from the
-	/// >			configuration at the end of the service initialization. It is intended to be
-	/// >			removed.
-	pub fn config_mut(&mut self) -> &mut FactoryFullConfiguration<Components::Factory> {
+	fn config_mut(&mut self) -> &mut Self::Config {
 		&mut self.config
 	}
 
-	/// Get event stream for telemetry connection established events.
-	pub fn telemetry_on_connect_stream(&self) -> TelemetryOnConnectNotifications {
+	fn telemetry_on_connect_stream(&self) -> mpsc::UnboundedReceiver<()> {
 		let (sink, stream) = mpsc::unbounded();
 		self._telemetry_on_connect_sinks.lock().push(sink);
 		stream
 	}
 
-	/// Return a shared instance of Telemetry (if enabled)
-	pub fn telemetry(&self) -> Option<tel::Telemetry> {
+	fn telemetry(&self) -> Option<tel::Telemetry> {
 		self._telemetry.as_ref().map(|t| t.clone())
 	}
 
-	/// Returns the keystore instance.
-	pub fn keystore(&self) -> keystore::KeyStorePtr {
+	fn keystore(&self) -> keystore::KeyStorePtr {
 		self.keystore.clone()
 	}
 
-	/// Spawns a task in the background that runs the future passed as parameter.
-	pub fn spawn_task(&self, task: impl Future<Item = (), Error = ()> + Send + 'static) {
+	fn spawn_task(&self, task: impl Future<Item = (), Error = ()> + Send + 'static) {
 		let _ = self.to_spawn_tx.unbounded_send(Box::new(task));
 	}
 
-	/// Spawns a task in the background that runs the future passed as
-	/// parameter. The given task is considered essential, i.e. if it errors we
-	/// trigger a service exit.
-	pub fn spawn_essential_task(&self, task: impl Future<Item = (), Error = ()> + Send + 'static) {
+	fn spawn_essential_task(&self, task: impl Future<Item = (), Error = ()> + Send + 'static) {
 		let essential_failed = self.essential_failed.clone();
 		let essential_task = Box::new(task.map_err(move |_| {
 			error!("Essential task failed. Shutting down service.");
@@ -517,62 +574,45 @@ impl<Components: components::Components> Service<Components> {
 		let _ = self.to_spawn_tx.unbounded_send(essential_task);
 	}
 
-	/// Returns a handle for spawning tasks.
-	pub fn spawn_task_handle(&self) -> SpawnTaskHandle {
+	fn spawn_task_handle(&self) -> SpawnTaskHandle {
 		SpawnTaskHandle {
 			sender: self.to_spawn_tx.clone(),
 		}
 	}
 
-	/// Starts an RPC query.
-	///
-	/// The query is passed as a string and must be a JSON text similar to what an HTTP client
-	/// would for example send.
-	///
-	/// Returns a `Future` that contains the optional response.
-	///
-	/// If the request subscribes you to events, the `Sender` in the `RpcSession` object is used to
-	/// send back spontaneous events.
-	pub fn rpc_query(&self, mem: &RpcSession, request: &str)
-		-> impl Future<Item = Option<String>, Error = ()>
-	{
-		self.rpc_handlers.handle_request(request, mem.metadata.clone())
+	fn rpc_query(&self, mem: &RpcSession, request: &str) -> Box<dyn Future<Item = Option<String>, Error = ()> + Send> {
+		Box::new(self.rpc_handlers.handle_request(request, mem.metadata.clone()))
 	}
 
-	/// Get shared client instance.
-	pub fn client(&self) -> Arc<ComponentClient<Components>> {
+	fn client(&self) -> Arc<client::Client<Self::Backend, Self::CallExecutor, Self::Block, Self::RuntimeApi>> {
 		self.client.clone()
 	}
 
-	/// Get clone of select chain.
-	pub fn select_chain(&self) -> Option<<Components as components::Components>::SelectChain> {
+	fn select_chain(&self) -> Option<Self::SelectChain> {
 		self.select_chain.clone()
 	}
 
-	/// Get shared network instance.
-	pub fn network(&self) -> Arc<components::NetworkService<Components>> {
+	fn network(&self) -> Arc<NetworkService<Self::Block, Self::NetworkSpecialization, H256>> {
 		self.network.clone()
 	}
 
-	/// Returns a receiver that periodically receives a status of the network.
-	pub fn network_status(&self) -> mpsc::UnboundedReceiver<(NetworkStatus<ComponentBlock<Components>>, NetworkState)> {
+	fn network_status(&self) -> mpsc::UnboundedReceiver<(NetworkStatus<Self::Block>, NetworkState)> {
 		let (sink, stream) = mpsc::unbounded();
 		self.network_status_sinks.lock().push(sink);
 		stream
 	}
 
-	/// Get shared transaction pool instance.
-	pub fn transaction_pool(&self) -> Arc<TransactionPool<Components::TransactionPoolApi>> {
+	fn transaction_pool(&self) -> Arc<TransactionPool<Self::TransactionPoolApi>> {
 		self.transaction_pool.clone()
 	}
 
-	/// Get a handle to a future that will resolve on exit.
-	pub fn on_exit(&self) -> ::exit_future::Exit {
+	fn on_exit(&self) -> ::exit_future::Exit {
 		self.exit.clone()
 	}
 }
 
-impl<Components> Future for Service<Components> where Components: components::Components {
+impl<TCfg, TBl, TCl, TSc, TNetStatus, TNet, TTxPool, TOc> Future for
+NewService<TCfg, TBl, TCl, TSc, TNetStatus, TNet, TTxPool, TOc> {
 	type Item = ();
 	type Error = Error;
 
@@ -603,9 +643,8 @@ impl<Components> Future for Service<Components> where Components: components::Co
 	}
 }
 
-impl<Components> Executor<Box<dyn Future<Item = (), Error = ()> + Send>>
-	for Service<Components> where Components: components::Components
-{
+impl<TCfg, TBl, TCl, TSc, TNetStatus, TNet, TTxPool, TOc> Executor<Box<dyn Future<Item = (), Error = ()> + Send>> for
+NewService<TCfg, TBl, TCl, TSc, TNetStatus, TNet, TTxPool, TOc> {
 	fn execute(
 		&self,
 		future: Box<dyn Future<Item = (), Error = ()> + Send>
@@ -746,7 +785,8 @@ pub struct NetworkStatus<B: BlockT> {
 	pub average_upload_per_sec: u64,
 }
 
-impl<Components> Drop for Service<Components> where Components: components::Components {
+impl<TCfg, TBl, TCl, TSc, TNetStatus, TNet, TTxPool, TOc> Drop for
+NewService<TCfg, TBl, TCl, TSc, TNetStatus, TNet, TTxPool, TOc> {
 	fn drop(&mut self) {
 		debug!(target: "service", "Substrate service shutdown");
 		if let Some(signal) = self.signal.take() {
@@ -757,7 +797,7 @@ impl<Components> Drop for Service<Components> where Components: components::Comp
 
 /// Starts RPC servers that run in their own thread, and returns an opaque object that keeps them alive.
 #[cfg(not(target_os = "unknown"))]
-fn start_rpc_servers<C, G, H: FnMut() -> components::RpcHandler>(
+fn start_rpc_servers<C, G, H: FnMut() -> rpc_servers::RpcHandler<rpc::Metadata>>(
 	config: &Configuration<C, G>,
 	mut gen_handler: H
 ) -> Result<Box<dyn std::any::Any + Send + Sync>, error::Error> {
@@ -906,225 +946,6 @@ where
 	}
 }
 
-/// Constructs a service factory with the given name that implements the `ServiceFactory` trait.
-/// The required parameters are required to be given in the exact order. Some parameters are followed
-/// by `{}` blocks. These blocks are required and used to initialize the given parameter.
-/// In these block it is required to write a closure that takes the same number of arguments,
-/// the corresponding function in the `ServiceFactory` trait provides.
-///
-/// # Example
-///
-/// ```
-/// # use substrate_service::{
-/// # 	construct_service_factory, Service, FullBackend, FullExecutor, LightBackend, LightExecutor,
-/// # 	FullComponents, LightComponents, FactoryFullConfiguration, FullClient
-/// # };
-/// # use transaction_pool::{self, txpool::{Pool as TransactionPool}};
-/// # use network::{config::DummyFinalityProofRequestBuilder, construct_simple_protocol};
-/// # use client::{self, LongestChain};
-/// # use consensus_common::import_queue::{BasicQueue, Verifier};
-/// # use consensus_common::{BlockOrigin, BlockImportParams, well_known_cache_keys::Id as CacheKeyId};
-/// # use node_runtime::{GenesisConfig, RuntimeApi};
-/// # use std::sync::Arc;
-/// # use node_primitives::Block;
-/// # use babe_primitives::AuthorityPair as BabePair;
-/// # use grandpa_primitives::AuthorityPair as GrandpaPair;
-/// # use sr_primitives::Justification;
-/// # use sr_primitives::traits::Block as BlockT;
-/// # use grandpa;
-/// # construct_simple_protocol! {
-/// # 	pub struct NodeProtocol where Block = Block { }
-/// # }
-/// # struct MyVerifier;
-/// # impl<B: BlockT> Verifier<B> for MyVerifier {
-/// # 	fn verify(
-/// # 		&mut self,
-/// # 		origin: BlockOrigin,
-/// # 		header: B::Header,
-/// # 		justification: Option<Justification>,
-/// # 		body: Option<Vec<B::Extrinsic>>,
-/// # 	) -> Result<(BlockImportParams<B>, Option<Vec<(CacheKeyId, Vec<u8>)>>), String> {
-/// # 		unimplemented!();
-/// # 	}
-/// # }
-/// type FullChainApi<T> = transaction_pool::ChainApi<
-/// 	client::Client<FullBackend<T>, FullExecutor<T>, Block, RuntimeApi>, Block>;
-/// type LightChainApi<T> = transaction_pool::ChainApi<
-/// 	client::Client<LightBackend<T>, LightExecutor<T>, Block, RuntimeApi>, Block>;
-///
-/// construct_service_factory! {
-/// 	struct Factory {
-/// 		// Declare the block type
-/// 		Block = Block,
-/// 		RuntimeApi = RuntimeApi,
-/// 		// Declare the network protocol and give an initializer.
-/// 		NetworkProtocol = NodeProtocol { |config| Ok(NodeProtocol::new()) },
-/// 		RuntimeDispatch = node_executor::Executor,
-/// 		FullTransactionPoolApi = FullChainApi<Self>
-/// 			{ |config, client| Ok(TransactionPool::new(config, transaction_pool::ChainApi::new(client))) },
-/// 		LightTransactionPoolApi = LightChainApi<Self>
-/// 			{ |config, client| Ok(TransactionPool::new(config, transaction_pool::ChainApi::new(client))) },
-/// 		Genesis = GenesisConfig,
-/// 		Configuration = (),
-/// 		FullService = FullComponents<Self>
-/// 			{ |config| <FullComponents<Factory>>::new(config) },
-/// 		// Setup as Consensus Authority (if the role and key are given)
-/// 		AuthoritySetup = {
-/// 			|service: Self::FullService| {
-/// 				Ok(service)
-/// 			}},
-/// 		LightService = LightComponents<Self>
-/// 			{ |config| <LightComponents<Factory>>::new(config) },
-/// 		FullImportQueue = BasicQueue<Block>
-/// 			{ |_, client, _, _| Ok(BasicQueue::new(MyVerifier, Box::new(client), None, None)) },
-/// 		LightImportQueue = BasicQueue<Block>
-/// 			{ |_, client| {
-/// 				let fprb = Box::new(DummyFinalityProofRequestBuilder::default()) as Box<_>;
-/// 				Ok((BasicQueue::new(MyVerifier, Box::new(client), None, None), fprb))
-/// 			}},
-/// 		SelectChain = LongestChain<FullBackend<Self>, Self::Block>
-/// 			{ |config: &FactoryFullConfiguration<Self>, client: Arc<FullClient<Self>>| {
-/// 				#[allow(deprecated)]
-/// 				Ok(LongestChain::new(client.backend().clone()))
-/// 			}},
-/// 		FinalityProofProvider = { |client: Arc<FullClient<Self>>| {
-/// 				Ok(Some(Arc::new(grandpa::FinalityProofProvider::new(client.clone(), client)) as _))
-/// 			}},
-/// 		RpcExtensions = (),
-/// 	}
-/// }
-/// ```
-#[macro_export]
-macro_rules! construct_service_factory {
-	(
-		$(#[$attr:meta])*
-		struct $name:ident {
-			Block = $block:ty,
-			RuntimeApi = $runtime_api:ty,
-			NetworkProtocol = $protocol:ty { $( $protocol_init:tt )* },
-			RuntimeDispatch = $dispatch:ty,
-			FullTransactionPoolApi = $full_transaction:ty { $( $full_transaction_init:tt )* },
-			LightTransactionPoolApi = $light_transaction:ty { $( $light_transaction_init:tt )* },
-			Genesis = $genesis:ty,
-			Configuration = $config:ty,
-			FullService = $full_service:ty { $( $full_service_init:tt )* },
-			AuthoritySetup = { $( $authority_setup:tt )* },
-			LightService = $light_service:ty { $( $light_service_init:tt )* },
-			FullImportQueue = $full_import_queue:ty
-				{ $( $full_import_queue_init:tt )* },
-			LightImportQueue = $light_import_queue:ty
-				{ $( $light_import_queue_init:tt )* },
-			SelectChain = $select_chain:ty
-				{ $( $select_chain_init:tt )* },
-			FinalityProofProvider = { $( $finality_proof_provider_init:tt )* },
-			RpcExtensions = $rpc_extensions_ty:ty
-				$( { $( $rpc_extensions:tt )* } )?,
-		}
-	) => {
-		$( #[$attr] )*
-		pub struct $name {}
-
-		#[allow(unused_variables)]
-		impl $crate::ServiceFactory for $name {
-			type Block = $block;
-			type RuntimeApi = $runtime_api;
-			type NetworkProtocol = $protocol;
-			type RuntimeDispatch = $dispatch;
-			type FullTransactionPoolApi = $full_transaction;
-			type LightTransactionPoolApi = $light_transaction;
-			type Genesis = $genesis;
-			type Configuration = $config;
-			type FullService = $full_service;
-			type LightService = $light_service;
-			type FullImportQueue = $full_import_queue;
-			type LightImportQueue = $light_import_queue;
-			type SelectChain = $select_chain;
-			type RpcExtensions = $rpc_extensions_ty;
-
-			fn build_full_transaction_pool(
-				config: $crate::TransactionPoolOptions,
-				client: $crate::Arc<$crate::FullClient<Self>>
-			) -> $crate::Result<$crate::TransactionPool<Self::FullTransactionPoolApi>, $crate::Error>
-			{
-				( $( $full_transaction_init )* ) (config, client)
-			}
-
-			fn build_light_transaction_pool(
-				config: $crate::TransactionPoolOptions,
-				client: $crate::Arc<$crate::LightClient<Self>>
-			) -> $crate::Result<$crate::TransactionPool<Self::LightTransactionPoolApi>, $crate::Error>
-			{
-				( $( $light_transaction_init )* ) (config, client)
-			}
-
-			fn build_network_protocol(config: &$crate::FactoryFullConfiguration<Self>)
-				-> $crate::Result<Self::NetworkProtocol, $crate::Error>
-			{
-				( $( $protocol_init )* ) (config)
-			}
-
-			fn build_select_chain(
-				config: &mut $crate::FactoryFullConfiguration<Self>,
-				client: Arc<$crate::FullClient<Self>>
-			) -> $crate::Result<Self::SelectChain, $crate::Error> {
-				( $( $select_chain_init )* ) (config, client)
-			}
-
-			fn build_full_import_queue(
-				config: &mut $crate::FactoryFullConfiguration<Self>,
-				client: $crate::Arc<$crate::FullClient<Self>>,
-				select_chain: Self::SelectChain,
-				transaction_pool: Option<Arc<$crate::TransactionPool<Self::FullTransactionPoolApi>>>,
-			) -> $crate::Result<Self::FullImportQueue, $crate::Error> {
-				( $( $full_import_queue_init )* ) (config, client, select_chain, transaction_pool)
-			}
-
-			fn build_light_import_queue(
-				config: &mut FactoryFullConfiguration<Self>,
-				client: Arc<$crate::LightClient<Self>>,
-			) -> Result<(Self::LightImportQueue, $crate::BoxFinalityProofRequestBuilder<$block>), $crate::Error> {
-				( $( $light_import_queue_init )* ) (config, client)
-			}
-
-			fn build_finality_proof_provider(
-				client: Arc<$crate::FullClient<Self>>
-			) -> Result<Option<Arc<$crate::FinalityProofProvider<Self::Block>>>, $crate::Error> {
-				( $( $finality_proof_provider_init )* ) (client)
-			}
-
-			fn new_light(
-				config: $crate::FactoryFullConfiguration<Self>
-			) -> $crate::Result<Self::LightService, $crate::Error>
-			{
-				( $( $light_service_init )* ) (config)
-			}
-
-			fn new_full(
-				config: $crate::FactoryFullConfiguration<Self>
-			) -> Result<Self::FullService, $crate::Error>
-			{
-				( $( $full_service_init )* ) (config).and_then(|service| {
-					($( $authority_setup )*)(service)
-				})
-			}
-
-			fn build_full_rpc_extensions(
-				client: Arc<$crate::FullClient<Self>>,
-				transaction_pool: Arc<$crate::TransactionPool<Self::FullTransactionPoolApi>>,
-			) -> Self::RpcExtensions {
-				$( ( $( $rpc_extensions )* ) (client, transaction_pool) )?
-			}
-
-			fn build_light_rpc_extensions(
-				client: Arc<$crate::LightClient<Self>>,
-				transaction_pool: Arc<$crate::TransactionPool<Self::LightTransactionPoolApi>>,
-			) -> Self::RpcExtensions {
-				$( ( $( $rpc_extensions )* ) (client, transaction_pool) )?
-			}
-		}
-	}
-}
-
 #[cfg(test)]
 mod tests {
 	use super::*;
diff --git a/core/service/test/src/lib.rs b/core/service/test/src/lib.rs
index c2895c5329496..870f287bff8f2 100644
--- a/core/service/test/src/lib.rs
+++ b/core/service/test/src/lib.rs
@@ -27,32 +27,31 @@ use tempdir::TempDir;
 use tokio::{runtime::Runtime, prelude::FutureExt};
 use tokio::timer::Interval;
 use service::{
-	ServiceFactory,
+	AbstractService,
+	ChainSpec,
 	Configuration,
-	FactoryFullConfiguration,
-	FactoryChainSpec,
 	Roles,
-	FactoryExtrinsic,
+	Error,
 };
 use network::{multiaddr, Multiaddr};
 use network::config::{NetworkConfiguration, TransportConfig, NodeKeyConfig, Secret, NonReservedPeerMode};
-use sr_primitives::generic::BlockId;
+use sr_primitives::{generic::BlockId, traits::Block as BlockT};
 use consensus::{BlockImportParams, BlockImport};
 
 /// Maximum duration of single wait call.
 const MAX_WAIT_TIME: Duration = Duration::from_secs(60 * 3);
 
-struct TestNet<F: ServiceFactory> {
+struct TestNet<G, F, L, U> {
 	runtime: Runtime,
-	authority_nodes: Vec<(usize, SyncService<F::FullService>, Multiaddr)>,
-	full_nodes: Vec<(usize, SyncService<F::FullService>, Multiaddr)>,
-	light_nodes: Vec<(usize, SyncService<F::LightService>, Multiaddr)>,
-	chain_spec: FactoryChainSpec<F>,
+	authority_nodes: Vec<(usize, SyncService<F>, U, Multiaddr)>,
+	full_nodes: Vec<(usize, SyncService<F>, U, Multiaddr)>,
+	light_nodes: Vec<(usize, SyncService<L>, Multiaddr)>,
+	chain_spec: ChainSpec<G>,
 	base_port: u16,
 	nodes: usize,
 }
 
-/// Wraps around an `Arc<Service>>` and implements `Future`.
+/// Wraps around an `Arc<Service>` and implements `Future`.
 pub struct SyncService<T>(Arc<Mutex<T>>);
 
 impl<T> SyncService<T> {
@@ -82,22 +81,24 @@ impl<T: Future<Item=(), Error=service::Error>> Future for SyncService<T> {
 	}
 }
 
-impl<F: ServiceFactory> TestNet<F> {
+impl<G, F, L, U> TestNet<G, F, L, U>
+where F: Send + 'static, L: Send +'static, U: Clone + Send + 'static
+{
 	pub fn run_until_all_full<FP, LP>(
 		&mut self,
 		full_predicate: FP,
 		light_predicate: LP,
 	)
 		where
-			FP: Send + Fn(usize, &SyncService<F::FullService>) -> bool + 'static,
-			LP: Send + Fn(usize, &SyncService<F::LightService>) -> bool + 'static,
+			FP: Send + Fn(usize, &SyncService<F>) -> bool + 'static,
+			LP: Send + Fn(usize, &SyncService<L>) -> bool + 'static,
 	{
 		let full_nodes = self.full_nodes.clone();
 		let light_nodes = self.light_nodes.clone();
 		let interval = Interval::new_interval(Duration::from_millis(100))
 			.map_err(|_| ())
 			.for_each(move |_| {
-				let full_ready = full_nodes.iter().all(|&(ref id, ref service, _)|
+				let full_ready = full_nodes.iter().all(|&(ref id, ref service, _, _)|
 					full_predicate(*id, service)
 				);
 
@@ -125,14 +126,14 @@ impl<F: ServiceFactory> TestNet<F> {
 	}
 }
 
-fn node_config<F: ServiceFactory> (
+fn node_config<G> (
 	index: usize,
-	spec: &FactoryChainSpec<F>,
+	spec: &ChainSpec<G>,
 	role: Roles,
 	key_seed: Option<String>,
 	base_port: u16,
 	root: &TempDir,
-) -> FactoryFullConfiguration<F>
+) -> Configuration<(), G>
 {
 	let root = root.path().join(format!("node-{}", index));
 
@@ -194,18 +195,18 @@ fn node_config<F: ServiceFactory> (
 	}
 }
 
-impl<F: ServiceFactory> TestNet<F> where
-	F::FullService: Future<Item=(), Error=service::Error>,
-	F::LightService: Future<Item=(), Error=service::Error>,
+impl<G, F, L, U> TestNet<G, F, L, U> where
+	F: AbstractService,
+	L: AbstractService,
 {
 	fn new(
 		temp: &TempDir,
-		spec: FactoryChainSpec<F>,
-		full: usize,
-		light: usize,
-		authorities: Vec<String>,
+		spec: ChainSpec<G>,
+		full: impl Iterator<Item = impl FnOnce(Configuration<(), G>) -> Result<(F, U), Error>>,
+		light: impl Iterator<Item = impl FnOnce(Configuration<(), G>) -> Result<L, Error>>,
+		authorities: impl Iterator<Item = (String, impl FnOnce(Configuration<(), G>) -> Result<(F, U), Error>)>,
 		base_port: u16
-	) -> TestNet<F> {
+	) -> TestNet<G, F, L, U> {
 		let _ = env_logger::try_init();
 		fdlimit::raise_fd_limit();
 		let runtime = Runtime::new().expect("Error creating tokio runtime");
@@ -222,79 +223,89 @@ impl<F: ServiceFactory> TestNet<F> where
 		net
 	}
 
-	fn insert_nodes(&mut self, temp: &TempDir, full: usize, light: usize, authorities: Vec<String>) {
-		let mut nodes = self.nodes;
-		let base_port = self.base_port;
-		let spec = &self.chain_spec;
+	fn insert_nodes(
+		&mut self,
+		temp: &TempDir,
+		full: impl Iterator<Item = impl FnOnce(Configuration<(), G>) -> Result<(F, U), Error>>,
+		light: impl Iterator<Item = impl FnOnce(Configuration<(), G>) -> Result<L, Error>>,
+		authorities: impl Iterator<Item = (String, impl FnOnce(Configuration<(), G>) -> Result<(F, U), Error>)>
+	) {
 		let executor = self.runtime.executor();
-		self.authority_nodes.extend(authorities.iter().enumerate().map(|(index, key)| {
-			let node_config = node_config::<F>(
-				index,
-				&spec,
+
+		for (key, authority) in authorities {
+			let node_config = node_config(
+				self.nodes,
+				&self.chain_spec,
 				Roles::AUTHORITY,
-				Some(key.clone()),
-				base_port,
+				Some(key),
+				self.base_port,
 				&temp,
 			);
 			let addr = node_config.network.listen_addresses.iter().next().unwrap().clone();
-			let service = SyncService::from(F::new_full(node_config).expect("Error creating test node service"));
+			let (service, user_data) = authority(node_config).expect("Error creating test node service");
+			let service = SyncService::from(service);
 
 			executor.spawn(service.clone().map_err(|_| ()));
 			let addr = addr.with(multiaddr::Protocol::P2p(service.get().network().local_peer_id().into()));
-			((index + nodes), service, addr)
-		}));
-		nodes += authorities.len();
+			self.authority_nodes.push((self.nodes, service, user_data, addr));
+			self.nodes += 1;
+		}
 
-		self.full_nodes.extend((nodes..nodes + full).map(|index| {
-			let node_config = node_config::<F>(index, &spec, Roles::FULL, None, base_port, &temp);
+		for full in full {
+			let node_config = node_config(self.nodes, &self.chain_spec, Roles::FULL, None, self.base_port, &temp);
 			let addr = node_config.network.listen_addresses.iter().next().unwrap().clone();
-			let service = SyncService::from(F::new_full(node_config).expect("Error creating test node service"));
+			let (service, user_data) = full(node_config).expect("Error creating test node service");
+			let service = SyncService::from(service);
 
 			executor.spawn(service.clone().map_err(|_| ()));
 			let addr = addr.with(multiaddr::Protocol::P2p(service.get().network().local_peer_id().into()));
-			(index, service, addr)
-		}));
-		nodes += full;
+			self.full_nodes.push((self.nodes, service, user_data, addr));
+			self.nodes += 1;
+		}
 
-		self.light_nodes.extend((nodes..nodes + light).map(|index| {
-			let node_config = node_config::<F>(index, &spec, Roles::LIGHT, None, base_port, &temp);
+		for light in light {
+			let node_config = node_config(self.nodes, &self.chain_spec, Roles::LIGHT, None, self.base_port, &temp);
 			let addr = node_config.network.listen_addresses.iter().next().unwrap().clone();
-			let service = SyncService::from(F::new_light(node_config).expect("Error creating test node service"));
+			let service = SyncService::from(light(node_config).expect("Error creating test node service"));
 
 			executor.spawn(service.clone().map_err(|_| ()));
 			let addr = addr.with(multiaddr::Protocol::P2p(service.get().network().local_peer_id().into()));
-			(index, service, addr)
-		}));
-		nodes += light;
-
-		self.nodes = nodes;
+			self.light_nodes.push((self.nodes, service, addr));
+			self.nodes += 1;
+		}
 	}
 }
 
-pub fn connectivity<F: ServiceFactory>(spec: FactoryChainSpec<F>) where
-	F::FullService: Future<Item=(), Error=service::Error>,
-	F::LightService: Future<Item=(), Error=service::Error>,
+pub fn connectivity<G, Fb, F, Lb, L>(spec: ChainSpec<G>, full_builder: Fb, light_builder: Lb) where
+	Fb: Fn(Configuration<(), G>) -> Result<F, Error>,
+	F: AbstractService,
+	Lb: Fn(Configuration<(), G>) -> Result<L, Error>,
+	L: AbstractService,
 {
 	const NUM_FULL_NODES: usize = 5;
 	const NUM_LIGHT_NODES: usize = 5;
 	{
 		let temp = TempDir::new("substrate-connectivity-test").expect("Error creating test dir");
 		let runtime = {
-			let mut network = TestNet::<F>::new(
+			let mut network = TestNet::new(
 				&temp,
 				spec.clone(),
-				NUM_FULL_NODES,
-				NUM_LIGHT_NODES,
-				vec![],
+				(0..NUM_FULL_NODES).map(|_| { |cfg| full_builder(cfg).map(|s| (s, ())) }),
+				(0..NUM_LIGHT_NODES).map(|_| { |cfg| light_builder(cfg) }),
+				// Note: this iterator is empty but we can't just use `iter::empty()`, otherwise
+				// the type of the closure cannot be inferred.
+				(0..0).map(|_| (String::new(), { |cfg| full_builder(cfg).map(|s| (s, ())) })),
 				30400,
 			);
 			info!("Checking star topology");
-			let first_address = network.full_nodes[0].2.clone();
-			for (_, service, _) in network.full_nodes.iter().skip(1) {
-				service.get().network().add_reserved_peer(first_address.to_string()).expect("Error adding reserved peer");
+			let first_address = network.full_nodes[0].3.clone();
+			for (_, service, _, _) in network.full_nodes.iter().skip(1) {
+				service.get().network().add_reserved_peer(first_address.to_string())
+					.expect("Error adding reserved peer");
 			}
 			for (_, service, _) in network.light_nodes.iter() {
-				service.get().network().add_reserved_peer(first_address.to_string()).expect("Error adding reserved peer");
+				service.get().network().add_reserved_peer(first_address.to_string())
+					.expect("Error adding reserved peer");
 			}
 			network.run_until_all_full(
 				|_index, service| service.get().network().num_connected() == NUM_FULL_NODES - 1
@@ -311,27 +322,31 @@ pub fn connectivity<F: ServiceFactory>(spec: FactoryChainSpec<F>) where
 	{
 		let temp = TempDir::new("substrate-connectivity-test").expect("Error creating test dir");
 		{
-			let mut network = TestNet::<F>::new(
+			let mut network = TestNet::new(
 				&temp,
 				spec,
-				NUM_FULL_NODES,
-				NUM_LIGHT_NODES,
-				vec![],
+				(0..NUM_FULL_NODES).map(|_| { |cfg| full_builder(cfg).map(|s| (s, ())) }),
+				(0..NUM_LIGHT_NODES).map(|_| { |cfg| light_builder(cfg) }),
+				// Note: this iterator is empty but we can't just use `iter::empty()`, otherwise
+				// the type of the closure cannot be inferred.
+				(0..0).map(|_| (String::new(), { |cfg| full_builder(cfg).map(|s| (s, ())) })),
 				30400,
 			);
 			info!("Checking linked topology");
-			let mut address = network.full_nodes[0].2.clone();
+			let mut address = network.full_nodes[0].3.clone();
 			let max_nodes = std::cmp::max(NUM_FULL_NODES, NUM_LIGHT_NODES);
 			for i in 0..max_nodes {
 				if i != 0 {
-					if let Some((_, service, node_id)) = network.full_nodes.get(i) {
-						service.get().network().add_reserved_peer(address.to_string()).expect("Error adding reserved peer");
+					if let Some((_, service, _, node_id)) = network.full_nodes.get(i) {
+						service.get().network().add_reserved_peer(address.to_string())
+							.expect("Error adding reserved peer");
 						address = node_id.clone();
 					}
 				}
 
 				if let Some((_, service, node_id)) = network.light_nodes.get(i) {
-					service.get().network().add_reserved_peer(address.to_string()).expect("Error adding reserved peer");
+					service.get().network().add_reserved_peer(address.to_string())
+						.expect("Error adding reserved peer");
 					address = node_id.clone();
 				}
 			}
@@ -345,42 +360,53 @@ pub fn connectivity<F: ServiceFactory>(spec: FactoryChainSpec<F>) where
 	}
 }
 
-pub fn sync<F, B, E>(spec: FactoryChainSpec<F>, mut block_factory: B, mut extrinsic_factory: E) where
-	F: ServiceFactory,
-	F::FullService: Future<Item=(), Error=service::Error>,
-	F::LightService: Future<Item=(), Error=service::Error>,
-	B: FnMut(&SyncService<F::FullService>) -> BlockImportParams<F::Block>,
-	E: FnMut(&SyncService<F::FullService>) -> FactoryExtrinsic<F>,
+pub fn sync<G, Fb, F, Lb, L, B, E, U>(
+	spec: ChainSpec<G>,
+	full_builder: Fb,
+	light_builder: Lb,
+	mut block_factory: B,
+	mut extrinsic_factory: E
+) where
+	Fb: Fn(Configuration<(), G>) -> Result<(F, U), Error>,
+	F: AbstractService,
+	Lb: Fn(Configuration<(), G>) -> Result<L, Error>,
+	L: AbstractService,
+	B: FnMut(&F, &U) -> BlockImportParams<F::Block>,
+	E: FnMut(&F, &U) -> <F::Block as BlockT>::Extrinsic,
+	U: Clone + Send + 'static,
 {
 	const NUM_FULL_NODES: usize = 10;
 	// FIXME: BABE light client support is currently not working.
 	const NUM_LIGHT_NODES: usize = 10;
 	const NUM_BLOCKS: usize = 512;
 	let temp = TempDir::new("substrate-sync-test").expect("Error creating test dir");
-	let mut network = TestNet::<F>::new(
+	let mut network = TestNet::new(
 		&temp,
 		spec.clone(),
-		NUM_FULL_NODES,
-		NUM_LIGHT_NODES,
-		vec![],
+		(0..NUM_FULL_NODES).map(|_| { |cfg| full_builder(cfg) }),
+		(0..NUM_LIGHT_NODES).map(|_| { |cfg| light_builder(cfg) }),
+		// Note: this iterator is empty but we can't just use `iter::empty()`, otherwise
+		// the type of the closure cannot be inferred.
+		(0..0).map(|_| (String::new(), { |cfg| full_builder(cfg) })),
 		30500,
 	);
 	info!("Checking block sync");
 	let first_address = {
 		let first_service = &network.full_nodes[0].1;
+		let first_user_data = &network.full_nodes[0].2;
 		let mut client = first_service.get().client();
 		for i in 0 .. NUM_BLOCKS {
 			if i % 128 == 0 {
 				info!("Generating #{}", i);
 			}
-			let import_data = block_factory(&first_service);
+			let import_data = block_factory(&first_service.get(), first_user_data);
 			client.import_block(import_data, HashMap::new()).expect("Error importing test block");
 		}
-		network.full_nodes[0].2.clone()
+		network.full_nodes[0].3.clone()
 	};
 
 	info!("Running sync");
-	for (_, service, _) in network.full_nodes.iter().skip(1) {
+	for (_, service, _, _) in network.full_nodes.iter().skip(1) {
 		service.get().network().add_reserved_peer(first_address.to_string()).expect("Error adding reserved peer");
 	}
 	for (_, service, _) in network.light_nodes.iter() {
@@ -395,8 +421,9 @@ pub fn sync<F, B, E>(spec: FactoryChainSpec<F>, mut block_factory: B, mut extrin
 
 	info!("Checking extrinsic propagation");
 	let first_service = network.full_nodes[0].1.clone();
+	let first_user_data = &network.full_nodes[0].2;
 	let best_block = BlockId::number(first_service.get().client().info().chain.best_number);
-	let extrinsic = extrinsic_factory(&first_service);
+	let extrinsic = extrinsic_factory(&first_service.get(), first_user_data);
 	first_service.get().transaction_pool().submit_one(&best_block, extrinsic).unwrap();
 	network.run_until_all_full(
 		|_index, service| service.get().transaction_pool().ready().count() == 1,
@@ -404,33 +431,39 @@ pub fn sync<F, B, E>(spec: FactoryChainSpec<F>, mut block_factory: B, mut extrin
 	);
 }
 
-pub fn consensus<F>(spec: FactoryChainSpec<F>, authorities: Vec<String>) where
-	F: ServiceFactory,
-	F::FullService: Future<Item=(), Error=service::Error>,
-	F::LightService: Future<Item=(), Error=service::Error>,
+pub fn consensus<G, Fb, F, Lb, L>(
+	spec: ChainSpec<G>,
+	full_builder: Fb,
+	light_builder: Lb,
+	authorities: impl IntoIterator<Item = String>
+) where
+	Fb: Fn(Configuration<(), G>) -> Result<F, Error>,
+	F: AbstractService,
+	Lb: Fn(Configuration<(), G>) -> Result<L, Error>,
+	L: AbstractService,
 {
 	const NUM_FULL_NODES: usize = 10;
 	const NUM_LIGHT_NODES: usize = 10;
 	const NUM_BLOCKS: usize = 10; // 10 * 2 sec block production time = ~20 seconds
 	let temp = TempDir::new("substrate-conensus-test").expect("Error creating test dir");
-	let mut network = TestNet::<F>::new(
+	let mut network = TestNet::new(
 		&temp,
 		spec.clone(),
-		NUM_FULL_NODES / 2,
-		NUM_LIGHT_NODES / 2,
-		authorities,
+		(0..NUM_FULL_NODES / 2).map(|_| { |cfg| full_builder(cfg).map(|s| (s, ())) }),
+		(0..NUM_LIGHT_NODES / 2).map(|_| { |cfg| light_builder(cfg) }),
+		authorities.into_iter().map(|key| (key, { |cfg| full_builder(cfg).map(|s| (s, ())) })),
 		30600,
 	);
 
 	info!("Checking consensus");
-	let first_address = network.authority_nodes[0].2.clone();
-	for (_, service, _) in network.full_nodes.iter() {
+	let first_address = network.authority_nodes[0].3.clone();
+	for (_, service, _, _) in network.full_nodes.iter() {
 		service.get().network().add_reserved_peer(first_address.to_string()).expect("Error adding reserved peer");
 	}
 	for (_, service, _) in network.light_nodes.iter() {
 		service.get().network().add_reserved_peer(first_address.to_string()).expect("Error adding reserved peer");
 	}
-	for (_, service, _) in network.authority_nodes.iter().skip(1) {
+	for (_, service, _, _) in network.authority_nodes.iter().skip(1) {
 		service.get().network().add_reserved_peer(first_address.to_string()).expect("Error adding reserved peer");
 	}
 	network.run_until_all_full(
@@ -441,8 +474,15 @@ pub fn consensus<F>(spec: FactoryChainSpec<F>, authorities: Vec<String>) where
 	);
 
 	info!("Adding more peers");
-	network.insert_nodes(&temp, NUM_FULL_NODES / 2, NUM_LIGHT_NODES / 2, vec![]);
-	for (_, service, _) in network.full_nodes.iter() {
+	network.insert_nodes(
+		&temp,
+		(0..NUM_FULL_NODES / 2).map(|_| { |cfg| full_builder(cfg).map(|s| (s, ())) }),
+		(0..NUM_LIGHT_NODES / 2).map(|_| { |cfg| light_builder(cfg) }),
+		// Note: this iterator is empty but we can't just use `iter::empty()`, otherwise
+		// the type of the closure cannot be inferred.
+		(0..0).map(|_| (String::new(), { |cfg| full_builder(cfg).map(|s| (s, ())) })),
+	);
+	for (_, service, _, _) in network.full_nodes.iter() {
 		service.get().network().add_reserved_peer(first_address.to_string()).expect("Error adding reserved peer");
 	}
 	for (_, service, _) in network.light_nodes.iter() {
diff --git a/core/sr-api-macros/src/decl_runtime_apis.rs b/core/sr-api-macros/src/decl_runtime_apis.rs
index 27f102740b83b..0e69c2b76d701 100644
--- a/core/sr-api-macros/src/decl_runtime_apis.rs
+++ b/core/sr-api-macros/src/decl_runtime_apis.rs
@@ -552,9 +552,9 @@ impl<'a> ToClientSideDecl<'a> {
 	fn fold_trait_item_method(&mut self, method: TraitItemMethod)
 		-> (TraitItemMethod, Option<TraitItemMethod>, TraitItemMethod) {
 		let crate_ = self.crate_;
-		let context_other = quote!( #crate_::runtime_api::ExecutionContext::Other );
+		let context = quote!( #crate_::runtime_api::ExecutionContext::OffchainCall(None) );
 		let fn_impl = self.create_method_runtime_api_impl(method.clone());
-		let fn_decl = self.create_method_decl(method.clone(), context_other);
+		let fn_decl = self.create_method_decl(method.clone(), context);
 		let fn_decl_ctx = self.create_method_decl_with_context(method);
 
 		(fn_decl, fn_impl, fn_decl_ctx)
diff --git a/core/sr-io/src/offchain/http.rs b/core/sr-io/src/offchain/http.rs
index 6685dd023f469..7aab309f1384c 100644
--- a/core/sr-io/src/offchain/http.rs
+++ b/core/sr-io/src/offchain/http.rs
@@ -224,7 +224,7 @@ pub enum Error {
 	/// Deadline has been reached.
 	DeadlineReached,
 	/// Request had timed out.
-	Timeout,
+	IoError,
 	/// Unknown error has been ecountered.
 	Unknown,
 }
@@ -283,8 +283,8 @@ impl PendingRequest {
 			.zip(requests.into_iter())
 			.map(|(status, req)| match status {
 				RequestStatus::DeadlineReached => Err(req),
-				RequestStatus::Timeout => Ok(Err(Error::Timeout)),
-				RequestStatus::Unknown => Ok(Err(Error::Unknown)),
+				RequestStatus::IoError => Ok(Err(Error::IoError)),
+				RequestStatus::Invalid => Ok(Err(Error::Unknown)),
 				RequestStatus::Finished(code) => Ok(Ok(Response::new(req.id, code))),
 			})
 			.collect()
diff --git a/core/sr-io/without_std.rs b/core/sr-io/without_std.rs
index 954eccc9cfafd..c5f2ac483fa81 100644
--- a/core/sr-io/without_std.rs
+++ b/core/sr-io/without_std.rs
@@ -1163,7 +1163,7 @@ impl OffchainApi for () {
 
 		statuses
 			.into_iter()
-			.map(|status| status.try_into().unwrap_or(offchain::HttpRequestStatus::Unknown))
+			.map(|status| status.try_into().unwrap_or(offchain::HttpRequestStatus::Invalid))
 			.collect()
 	}
 
diff --git a/core/sr-primitives/src/traits.rs b/core/sr-primitives/src/traits.rs
index abbbef3a5b260..3dc1649e495d4 100644
--- a/core/sr-primitives/src/traits.rs
+++ b/core/sr-primitives/src/traits.rs
@@ -796,7 +796,7 @@ impl<T: BlindCheckable, Context> Checkable<Context> for T {
 /// An abstract error concerning an attempt to verify, check or dispatch the transaction. This
 /// cannot be more concrete because it's designed to work reasonably well over a broad range of
 /// possible transaction types.
-#[cfg_attr(feature = "std", derive(Debug))]
+#[cfg_attr(feature = "std", derive(PartialEq, Debug))]
 pub enum DispatchError {
 	/// General error to do with the inability to pay some fees (e.g. account balance too low).
 	Payment,
diff --git a/core/sr-version/src/lib.rs b/core/sr-version/src/lib.rs
index 731c5b63c7137..f787d8dd7ebfb 100644
--- a/core/sr-version/src/lib.rs
+++ b/core/sr-version/src/lib.rs
@@ -96,7 +96,13 @@ pub struct RuntimeVersion {
 	pub impl_version: u32,
 
 	/// List of supported API "features" along with their versions.
-	#[cfg_attr(feature = "std", serde(serialize_with = "apis_serialize::serialize"))]
+	#[cfg_attr(
+		feature = "std",
+		serde(
+			serialize_with = "apis_serialize::serialize",
+			deserialize_with = "apis_serialize::deserialize",
+		)
+	)]
 	pub apis: ApisVec,
 }
 
@@ -163,7 +169,7 @@ impl NativeVersion {
 mod apis_serialize {
 	use super::*;
 	use impl_serde::serialize as bytes;
-	use serde::{Serializer, ser::SerializeTuple};
+	use serde::{Serializer, de, ser::SerializeTuple};
 
 	#[derive(Serialize)]
 	struct ApiId<'a>(
@@ -187,4 +193,44 @@ mod apis_serialize {
 	{
 		bytes::serialize(*apis, ser)
 	}
+
+	#[derive(Deserialize)]
+	struct ApiIdOwned(
+		#[serde(deserialize_with="deserialize_bytes")]
+		super::ApiId,
+		u32,
+	);
+
+	pub fn deserialize<'de, D>(deserializer: D) -> Result<ApisVec, D::Error> where
+		D: de::Deserializer<'de>,
+	{
+		struct Visitor;
+		impl<'de> de::Visitor<'de> for Visitor {
+			type Value = ApisVec;
+
+			fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+				formatter.write_str("a sequence of api id and version tuples")
+			}
+
+			fn visit_seq<V>(self, mut visitor: V) -> Result<Self::Value, V::Error> where
+				V: de::SeqAccess<'de>,
+			{
+				let mut apis = Vec::new();
+				while let Some(value) = visitor.next_element::<ApiIdOwned>()? {
+					apis.push((value.0, value.1));
+				}
+				Ok(apis.into())
+			}
+		}
+		deserializer.deserialize_seq(Visitor)
+	}
+
+	pub fn deserialize_bytes<'de, D>(d: D) -> Result<super::ApiId, D::Error> where
+		D: de::Deserializer<'de>
+	{
+		let bytes = bytes::deserialize_check_len(d, bytes::ExpectedLen::Exact(8))?;
+		let mut arr = [0; 8];
+		arr.copy_from_slice(&bytes);
+		Ok(arr)
+	}
 }
diff --git a/core/test-runtime/client/src/lib.rs b/core/test-runtime/client/src/lib.rs
index f1cbb6fd8c921..ad5badf8bf363 100644
--- a/core/test-runtime/client/src/lib.rs
+++ b/core/test-runtime/client/src/lib.rs
@@ -51,8 +51,7 @@ mod local_executor {
 	native_executor_instance!(
 		pub LocalExecutor,
 		runtime::api::dispatch,
-		runtime::native_version,
-		runtime::WASM_BINARY
+		runtime::native_version
 	);
 }
 
@@ -97,12 +96,34 @@ pub type LightExecutor = client::light::call_executor::RemoteOrLocalCallExecutor
 pub struct GenesisParameters {
 	support_changes_trie: bool,
 	heap_pages_override: Option<u64>,
+	extra_storage: Vec<(Vec<u8>, Vec<u8>)>,
+}
+
+impl GenesisParameters {
+	fn genesis_config(&self) -> GenesisConfig {
+		GenesisConfig::new(
+			self.support_changes_trie,
+			vec![
+				sr25519::Public::from(Sr25519Keyring::Alice).into(),
+				sr25519::Public::from(Sr25519Keyring::Bob).into(),
+				sr25519::Public::from(Sr25519Keyring::Charlie).into(),
+			],
+			vec![
+				AccountKeyring::Alice.into(),
+				AccountKeyring::Bob.into(),
+				AccountKeyring::Charlie.into(),
+			],
+			1000,
+			self.heap_pages_override,
+			self.extra_storage.clone(),
+		)
+	}
 }
 
 impl generic_test_client::GenesisInit for GenesisParameters {
 	fn genesis_storage(&self) -> (StorageOverlay, ChildrenStorageOverlay) {
 		use codec::Encode;
-		let mut storage = genesis_config(self.support_changes_trie, self.heap_pages_override).genesis_map();
+		let mut storage = self.genesis_config().genesis_map();
 
 		let child_roots = storage.1.iter().map(|(sk, child_map)| {
 			let state_root = <<<runtime::Block as BlockT>::Header as HeaderT>::Hashing as HashT>::trie_root(
@@ -157,6 +178,13 @@ pub trait TestClientBuilderExt<B>: Sized {
 	/// Override the default value for Wasm heap pages.
 	fn set_heap_pages(self, heap_pages: u64) -> Self;
 
+	/// Add an extra value into the genesis storage.
+	///
+	/// # Panics
+	///
+	/// Panics if the key is empty.
+	fn add_extra_storage<K: Into<Vec<u8>>, V: Into<Vec<u8>>>(self, key: K, value: V) -> Self;
+
 	/// Build the test client.
 	fn build(self) -> Client<B> {
 		self.build_with_longest_chain().0
@@ -182,28 +210,18 @@ impl<B> TestClientBuilderExt<B> for TestClientBuilder<
 		self
 	}
 
+	fn add_extra_storage<K: Into<Vec<u8>>, V: Into<Vec<u8>>>(mut self, key: K, value: V) -> Self {
+		let key = key.into();
+		assert!(!key.is_empty());
+		self.genesis_init_mut().extra_storage.push((key, value.into()));
+		self
+	}
+
 	fn build_with_longest_chain(self) -> (Client<B>, client::LongestChain<B, runtime::Block>) {
 		self.build_with_native_executor(None)
 	}
 }
 
-fn genesis_config(support_changes_trie: bool, heap_pages_override: Option<u64>) -> GenesisConfig {
-	GenesisConfig::new(
-		support_changes_trie,
-		vec![
-			sr25519::Public::from(Sr25519Keyring::Alice).into(),
-			sr25519::Public::from(Sr25519Keyring::Bob).into(),
-			sr25519::Public::from(Sr25519Keyring::Charlie).into(),
-		], vec![
-			AccountKeyring::Alice.into(),
-			AccountKeyring::Bob.into(),
-			AccountKeyring::Charlie.into(),
-		],
-		1000,
-		heap_pages_override,
-	)
-}
-
 /// Creates new client instance used for tests.
 pub fn new() -> Client<Backend> {
 	TestClientBuilder::new().build()
diff --git a/core/test-runtime/src/genesismap.rs b/core/test-runtime/src/genesismap.rs
index 7686ed08bc02e..c2dd49156d7a0 100644
--- a/core/test-runtime/src/genesismap.rs
+++ b/core/test-runtime/src/genesismap.rs
@@ -25,10 +25,12 @@ use sr_primitives::traits::{Block as BlockT, Hash as HashT, Header as HeaderT};
 
 /// Configuration of a general Substrate test genesis block.
 pub struct GenesisConfig {
-	pub changes_trie_config: Option<ChangesTrieConfiguration>,
-	pub authorities: Vec<AuthorityId>,
-	pub balances: Vec<(AccountId, u64)>,
-	pub heap_pages_override: Option<u64>,
+	changes_trie_config: Option<ChangesTrieConfiguration>,
+	authorities: Vec<AuthorityId>,
+	balances: Vec<(AccountId, u64)>,
+	heap_pages_override: Option<u64>,
+	/// Additional storage key pairs that will be added to the genesis map.
+	extra_storage: Vec<(Vec<u8>, Vec<u8>)>,
 }
 
 impl GenesisConfig {
@@ -38,6 +40,7 @@ impl GenesisConfig {
 		endowed_accounts: Vec<AccountId>,
 		balance: u64,
 		heap_pages_override: Option<u64>,
+		extra_storage: Vec<(Vec<u8>, Vec<u8>)>,
 	) -> Self {
 		GenesisConfig {
 			changes_trie_config: match support_changes_trie {
@@ -47,6 +50,7 @@ impl GenesisConfig {
 			authorities: authorities.clone(),
 			balances: endowed_accounts.into_iter().map(|a| (a, balance)).collect(),
 			heap_pages_override,
+			extra_storage,
 		}
 	}
 
@@ -70,6 +74,10 @@ impl GenesisConfig {
 			map.insert(well_known_keys::CHANGES_TRIE_CONFIG.to_vec(), changes_trie_config.encode());
 		}
 		map.insert(twox_128(&b"sys:auth"[..])[..].to_vec(), self.authorities.encode());
+		// Finally, add the extra storage entries.
+		for (key, value) in self.extra_storage.iter().cloned() {
+			map.insert(key, value);
+		}
 		(map, Default::default())
 	}
 }
diff --git a/core/test-runtime/src/system.rs b/core/test-runtime/src/system.rs
index f3c890cf79f54..63f9c0050b73c 100644
--- a/core/test-runtime/src/system.rs
+++ b/core/test-runtime/src/system.rs
@@ -62,6 +62,12 @@ pub fn initialize_block(header: &Header) {
 	<ParentHash>::put(&header.parent_hash);
 	<StorageDigest>::put(header.digest());
 	storage::unhashed::put(well_known_keys::EXTRINSIC_INDEX, &0u32);
+
+	// try to read something that depends on current header digest
+	// so that it'll be included in execution proof
+	if let Some(generic::DigestItem::Other(v)) = header.digest().logs().iter().next() {
+		let _: Option<u32> = storage::unhashed::get(&v);
+	}
 }
 
 pub fn get_block_number() -> Option<BlockNumber> {
@@ -104,6 +110,12 @@ fn execute_block_with_state_root_handler(
 		assert!(txs_root == header.extrinsics_root, "Transaction trie root must be valid.");
 	}
 
+	// try to read something that depends on current header digest
+	// so that it'll be included in execution proof
+	if let Some(generic::DigestItem::Other(v)) = header.digest().logs().iter().next() {
+		let _: Option<u32> = storage::unhashed::get(&v);
+	}
+
 	// execute transactions
 	block.extrinsics.iter().enumerate().for_each(|(i, e)| {
 		storage::unhashed::put(well_known_keys::EXTRINSIC_INDEX, &(i as u32));
diff --git a/node-template/src/cli.rs b/node-template/src/cli.rs
index 4d672491c18e6..f6edbb2cc3ee3 100644
--- a/node-template/src/cli.rs
+++ b/node-template/src/cli.rs
@@ -4,9 +4,8 @@ use std::cell::RefCell;
 use tokio::runtime::Runtime;
 pub use substrate_cli::{VersionInfo, IntoExit, error};
 use substrate_cli::{informant, parse_and_prepare, ParseAndPrepare, NoCustom};
-use substrate_service::{ServiceFactory, Roles as ServiceRoles};
+use substrate_service::{AbstractService, Roles as ServiceRoles};
 use crate::chain_spec;
-use std::ops::Deref;
 use log::info;
 
 /// Parse command line arguments into service configuration.
@@ -16,7 +15,8 @@ pub fn run<I, T, E>(args: I, exit: E, version: VersionInfo) -> error::Result<()>
 	E: IntoExit,
 {
 	match parse_and_prepare::<NoCustom, NoCustom, _>(&version, "substrate-node", args) {
-		ParseAndPrepare::Run(cmd) => cmd.run(load_spec, exit, |exit, _cli_args, _custom_args, config| {
+		ParseAndPrepare::Run(cmd) => cmd.run::<(), _, _, _, _>(load_spec, exit,
+		|exit, _cli_args, _custom_args, config| {
 			info!("{}", version.name);
 			info!("  version {}", config.full_version());
 			info!("  by {}, 2017, 2018", version.author);
@@ -27,21 +27,24 @@ pub fn run<I, T, E>(args: I, exit: E, version: VersionInfo) -> error::Result<()>
 			match config.roles {
 				ServiceRoles::LIGHT => run_until_exit(
 					runtime,
-				 	service::Factory::new_light(config).map_err(|e| format!("{:?}", e))?,
+				 	service::new_light(config).map_err(|e| format!("{:?}", e))?,
 					exit
 				),
 				_ => run_until_exit(
 					runtime,
-					service::Factory::new_full(config).map_err(|e| format!("{:?}", e))?,
+					service::new_full(config).map_err(|e| format!("{:?}", e))?,
 					exit
 				),
 			}.map_err(|e| format!("{:?}", e))
 		}),
 		ParseAndPrepare::BuildSpec(cmd) => cmd.run(load_spec),
-		ParseAndPrepare::ExportBlocks(cmd) => cmd.run::<service::Factory, _, _>(load_spec, exit),
-		ParseAndPrepare::ImportBlocks(cmd) => cmd.run::<service::Factory, _, _>(load_spec, exit),
+		ParseAndPrepare::ExportBlocks(cmd) => cmd.run_with_builder::<(), _, _, _, _, _>(|config|
+			Ok(new_full_start!(config).0), load_spec, exit),
+		ParseAndPrepare::ImportBlocks(cmd) => cmd.run_with_builder::<(), _, _, _, _, _>(|config|
+			Ok(new_full_start!(config).0), load_spec, exit),
 		ParseAndPrepare::PurgeChain(cmd) => cmd.run(load_spec),
-		ParseAndPrepare::RevertChain(cmd) => cmd.run::<service::Factory, _>(load_spec),
+		ParseAndPrepare::RevertChain(cmd) => cmd.run_with_builder::<(), _, _, _, _>(|config|
+			Ok(new_full_start!(config).0), load_spec),
 		ParseAndPrepare::CustomCommand(_) => Ok(())
 	}?;
 
@@ -55,14 +58,13 @@ fn load_spec(id: &str) -> Result<Option<chain_spec::ChainSpec>, String> {
 	})
 }
 
-fn run_until_exit<T, C, E>(
+fn run_until_exit<T, E>(
 	mut runtime: Runtime,
 	service: T,
 	e: E,
-) -> error::Result<()> where
-	T: Deref<Target=substrate_service::Service<C>>,
-	T: Future<Item = (), Error = substrate_service::error::Error> + Send + 'static,
-	C: substrate_service::Components,
+) -> error::Result<()>
+where
+	T: AbstractService,
 	E: IntoExit,
 {
 	let (exit_send, exit) = exit_future::signal();
@@ -99,7 +101,8 @@ impl IntoExit for Exit {
 
 		let exit_send_cell = RefCell::new(Some(exit_send));
 		ctrlc::set_handler(move || {
-			if let Some(exit_send) = exit_send_cell.try_borrow_mut().expect("signal handler not reentrant; qed").take() {
+			let exit_send = exit_send_cell.try_borrow_mut().expect("signal handler not reentrant; qed").take();
+			if let Some(exit_send) = exit_send {
 				exit_send.send(()).expect("Error sending exit notification");
 			}
 		}).expect("Error setting Ctrl-C handler");
diff --git a/node-template/src/main.rs b/node-template/src/main.rs
index 18e9638833fd2..024efcc7db541 100644
--- a/node-template/src/main.rs
+++ b/node-template/src/main.rs
@@ -4,6 +4,7 @@
 #![warn(unused_extern_crates)]
 
 mod chain_spec;
+#[macro_use]
 mod service;
 mod cli;
 
diff --git a/node-template/src/service.rs b/node-template/src/service.rs
index 2baa0c7631373..7bb4cc8d52d68 100644
--- a/node-template/src/service.rs
+++ b/node-template/src/service.rs
@@ -1,32 +1,24 @@
-#![warn(unused_extern_crates)]
-
 //! Service and ServiceFactory implementation. Specialized wrapper over substrate service.
 
 use std::sync::Arc;
 use std::time::Duration;
-use substrate_client::{self as client, LongestChain};
-use babe::{import_queue, start_babe, BabeImportQueue, Config};
+use substrate_client::LongestChain;
+use babe::{import_queue, start_babe, Config};
 use grandpa::{self, FinalityProofProvider as GrandpaFinalityProofProvider};
 use futures::prelude::*;
 use node_template_runtime::{self, GenesisConfig, opaque::Block, RuntimeApi, WASM_BINARY};
-use substrate_service::{
-	FactoryFullConfiguration, LightComponents, FullComponents, FullBackend,
-	FullClient, LightClient, LightBackend, FullExecutor, LightExecutor,
-	error::{Error as ServiceError},
-};
+use substrate_service::{error::{Error as ServiceError}, AbstractService, Configuration, ServiceBuilder};
 use transaction_pool::{self, txpool::{Pool as TransactionPool}};
 use inherents::InherentDataProviders;
 use network::construct_simple_protocol;
 use substrate_executor::native_executor_instance;
-use substrate_service::{ServiceFactory, construct_service_factory, TelemetryOnConnect};
 pub use substrate_executor::NativeExecutor;
 
 // Our native executor instance.
 native_executor_instance!(
 	pub Executor,
 	node_template_runtime::api::dispatch,
-	node_template_runtime::native_version,
-	WASM_BINARY
+	node_template_runtime::native_version
 );
 
 construct_simple_protocol! {
@@ -34,235 +26,205 @@ construct_simple_protocol! {
 	pub struct NodeProtocol where Block = Block { }
 }
 
-type BabeBlockImportForService<F> = babe::BabeBlockImport<
-	FullBackend<F>,
-	FullExecutor<F>,
-	<F as ServiceFactory>::Block,
-	grandpa::BlockImportForService<F>,
-	<F as ServiceFactory>::RuntimeApi,
-	client::Client<
-		FullBackend<F>,
-		FullExecutor<F>,
-		<F as ServiceFactory>::Block,
-		<F as ServiceFactory>::RuntimeApi
-	>,
->;
-
-pub struct NodeConfig<F: ServiceFactory> {
-	/// GRANDPA and BABE connection to import block.
-	// FIXME #1134 rather than putting this on the config, let's have an actual intermediate setup state
-	pub import_setup: Option<(
-		BabeBlockImportForService<F>,
-		grandpa::LinkHalfForService<F>,
-		babe::BabeLink,
-	)>,
-	/// Tasks that were created by previous setup steps and should be spawned.
-	pub tasks_to_spawn: Option<Vec<Box<dyn Future<Item = (), Error = ()> + Send>>>,
-	inherent_data_providers: InherentDataProviders,
-}
-
-impl<F> Default for NodeConfig<F> where F: ServiceFactory {
-	fn default() -> NodeConfig<F> {
-		NodeConfig {
-			import_setup: None,
-			inherent_data_providers: InherentDataProviders::new(),
-			tasks_to_spawn: None,
-		}
-	}
-}
-
-construct_service_factory! {
-	struct Factory {
-		Block = Block,
-		RuntimeApi = RuntimeApi,
-		NetworkProtocol = NodeProtocol { |config| Ok(NodeProtocol::new()) },
-		RuntimeDispatch = Executor,
-		FullTransactionPoolApi =
-			transaction_pool::ChainApi<
-				client::Client<FullBackend<Self>, FullExecutor<Self>, Block, RuntimeApi>,
-				Block
-			> {
-				|config, client|
-					Ok(TransactionPool::new(config, transaction_pool::ChainApi::new(client)))
-			},
-		LightTransactionPoolApi =
-			transaction_pool::ChainApi<
-				client::Client<LightBackend<Self>, LightExecutor<Self>, Block, RuntimeApi>,
-				Block
-			> {
-				|config, client|
-					Ok(TransactionPool::new(config, transaction_pool::ChainApi::new(client)))
-			},
-		Genesis = GenesisConfig,
-		Configuration = NodeConfig<Self>,
-		FullService = FullComponents<Self> {
-			|config: FactoryFullConfiguration<Self>| FullComponents::<Factory>::new(config)
-		},
-		AuthoritySetup = {
-			|mut service: Self::FullService| {
-				let (block_import, link_half, babe_link) =
-					service.config_mut().custom.import_setup.take()
-						.expect("Link Half and Block Import are present for Full Services or setup failed before. qed");
-
-				// spawn any futures that were created in the previous setup steps
-				if let Some(tasks) = service.config_mut().custom.tasks_to_spawn.take() {
-					for task in tasks {
-						service.spawn_task(
-							task.select(service.on_exit())
-								.map(|_| ())
-								.map_err(|_| ())
-						);
-					}
-				}
-
-				if service.config().roles.is_authority() {
-					let proposer = basic_authorship::ProposerFactory {
-						client: service.client(),
-						transaction_pool: service.transaction_pool(),
-					};
-
-					let client = service.client();
-					let select_chain = service.select_chain()
-						.ok_or(ServiceError::SelectChainRequired)?;
-
-					let babe_config = babe::BabeParams {
-						config: Config::get_or_compute(&*client)?,
-						keystore: service.keystore(),
-						client,
-						select_chain,
-						block_import,
-						env: proposer,
-						sync_oracle: service.network(),
-						inherent_data_providers: service.config()
-							.custom.inherent_data_providers.clone(),
-						force_authoring: service.config().force_authoring,
-						time_source: babe_link,
-					};
-
-					let babe = start_babe(babe_config)?;
-					let select = babe.select(service.on_exit()).then(|_| Ok(()));
-
-					// the BABE authoring task is considered infallible, i.e. if it
-					// fails we take down the service with it.
-					service.spawn_essential_task(select);
-				}
-
-				let config = grandpa::Config {
-					// FIXME #1578 make this available through chainspec
-					gossip_duration: Duration::from_millis(333),
-					justification_period: 4096,
-					name: Some(service.config().name.clone()),
-					keystore: Some(service.keystore()),
-				};
-
-				match (service.config().roles.is_authority(), service.config().disable_grandpa) {
-					(false, false) => {
-						// start the lightweight GRANDPA observer
-						service.spawn_task(Box::new(grandpa::run_grandpa_observer(
-							config,
-							link_half,
-							service.network(),
-							service.on_exit(),
-						)?));
-					},
-					(true, false) => {
-						// start the full GRANDPA voter
-						let telemetry_on_connect = TelemetryOnConnect {
-							telemetry_connection_sinks: service.telemetry_on_connect_stream(),
-						};
-						let grandpa_config = grandpa::GrandpaParams {
-							config: config,
-							link: link_half,
-							network: service.network(),
-							inherent_data_providers:
-								service.config().custom.inherent_data_providers.clone(),
-							on_exit: service.on_exit(),
-							telemetry_on_connect: Some(telemetry_on_connect),
-						};
-
-						// the GRANDPA voter task is considered infallible, i.e.
-						// if it fails we take down the service with it.
-						service.spawn_essential_task(grandpa::run_grandpa_voter(grandpa_config)?);
-					},
-					(_, true) => {
-						grandpa::setup_disabled_grandpa(
-							service.client(),
-							&service.config().custom.inherent_data_providers,
-							service.network(),
-						)?;
-					},
-				}
-
-				Ok(service)
-			}
-		},
-		LightService = LightComponents<Self>
-			{ |config| <LightComponents<Factory>>::new(config) },
-		FullImportQueue = BabeImportQueue<Self::Block> {
-			|
-				config: &mut FactoryFullConfiguration<Self>,
-				client: Arc<FullClient<Self>>,
-				select_chain: Self::SelectChain,
-				transaction_pool: Option<Arc<TransactionPool<Self::FullTransactionPoolApi>>>,
-			| {
+/// Starts a `ServiceBuilder` for a full service.
+///
+/// Use this macro if you don't actually need the full service, but just the builder in order to
+/// be able to perform chain operations.
+macro_rules! new_full_start {
+	($config:expr) => {{
+		let mut import_setup = None;
+		let inherent_data_providers = inherents::InherentDataProviders::new();
+		let mut tasks_to_spawn = None;
+
+		let builder = substrate_service::ServiceBuilder::new_full::<
+			node_template_runtime::opaque::Block, node_template_runtime::RuntimeApi, crate::service::Executor
+		>($config)?
+			.with_select_chain(|_config, client| {
+				#[allow(deprecated)]
+				Ok(substrate_client::LongestChain::new(client.backend().clone()))
+			})?
+			.with_transaction_pool(|config, client|
+				Ok(transaction_pool::txpool::Pool::new(config, transaction_pool::ChainApi::new(client)))
+			)?
+			.with_import_queue(|_config, client, mut select_chain, transaction_pool| {
+				let select_chain = select_chain.take()
+					.ok_or_else(|| substrate_service::Error::SelectChainRequired)?;
 				let (block_import, link_half) =
-					grandpa::block_import::<_, _, _, RuntimeApi, FullClient<Self>, _>(
+					grandpa::block_import::<_, _, _, node_template_runtime::RuntimeApi, _, _>(
 						client.clone(), client.clone(), select_chain
 					)?;
 				let justification_import = block_import.clone();
-				let (import_queue, babe_link, babe_block_import, pruning_task) = import_queue(
-					Config::get_or_compute(&*client)?,
+
+				let (import_queue, babe_link, babe_block_import, pruning_task) = babe::import_queue(
+					babe::Config::get_or_compute(&*client)?,
 					block_import,
 					Some(Box::new(justification_import)),
 					None,
 					client.clone(),
 					client,
-					config.custom.inherent_data_providers.clone(),
-					transaction_pool,
+					inherent_data_providers.clone(),
+					Some(transaction_pool)
 				)?;
-				config.custom.import_setup = Some((babe_block_import.clone(), link_half, babe_link));
-				config.custom.tasks_to_spawn = Some(vec![Box::new(pruning_task)]);
+
+				import_setup = Some((babe_block_import.clone(), link_half, babe_link));
+				tasks_to_spawn = Some(vec![Box::new(pruning_task)]);
+
 				Ok(import_queue)
-			}
-		},
-		LightImportQueue = BabeImportQueue<Self::Block>
-			{ |config: &FactoryFullConfiguration<Self>, client: Arc<LightClient<Self>>| {
-				#[allow(deprecated)]
-				let fetch_checker = client.backend().blockchain().fetcher()
-					.upgrade()
-					.map(|fetcher| fetcher.checker().clone())
-					.ok_or_else(|| "Trying to start light import queue without active fetch checker")?;
-				let block_import = grandpa::light_block_import::<_, _, _, RuntimeApi, LightClient<Self>>(
-					client.clone(), Arc::new(fetch_checker), client.clone()
-				)?;
+			})?;
 
-				let finality_proof_import = block_import.clone();
-				let finality_proof_request_builder =
-					finality_proof_import.create_finality_proof_request_builder();
+		(builder, import_setup, inherent_data_providers, tasks_to_spawn)
+	}}
+}
 
-				// FIXME: pruning task isn't started since light client doesn't do `AuthoritySetup`.
-				let (import_queue, ..) = import_queue::<_, _, _, _, _, _, TransactionPool<Self::FullTransactionPoolApi>>(
-					Config::get_or_compute(&*client)?,
-					block_import,
-					None,
-					Some(Box::new(finality_proof_import)),
-					client.clone(),
-					client,
-					config.custom.inherent_data_providers.clone(),
-					None,
-				)?;
+/// Builds a new service for a full client.
+pub fn new_full<C: Send + Default + 'static>(config: Configuration<C, GenesisConfig>)
+	-> Result<impl AbstractService, ServiceError>
+{
+
+	let (builder, mut import_setup, inherent_data_providers, mut tasks_to_spawn) = new_full_start!(config);
+
+	let service = builder.with_network_protocol(|_| Ok(NodeProtocol::new()))?
+		.with_finality_proof_provider(|client|
+			Ok(Arc::new(GrandpaFinalityProofProvider::new(client.clone(), client)) as _)
+		)?
+		.build()?;
+
+	let (block_import, link_half, babe_link) =
+		import_setup.take()
+			.expect("Link Half and Block Import are present for Full Services or setup failed before. qed");
+
+	// spawn any futures that were created in the previous setup steps
+	if let Some(tasks) = tasks_to_spawn.take() {
+		for task in tasks {
+			service.spawn_task(
+				task.select(service.on_exit())
+					.map(|_| ())
+					.map_err(|_| ())
+			);
+		}
+	}
 
-				Ok((import_queue, finality_proof_request_builder))
-			}},
-		SelectChain = LongestChain<FullBackend<Self>, Self::Block>
-			{ |config: &FactoryFullConfiguration<Self>, client: Arc<FullClient<Self>>| {
-				#[allow(deprecated)]
-				Ok(LongestChain::new(client.backend().clone()))
-			}
+	if service.config().roles.is_authority() {
+		let proposer = basic_authorship::ProposerFactory {
+			client: service.client(),
+			transaction_pool: service.transaction_pool(),
+		};
+
+		let client = service.client();
+		let select_chain = service.select_chain()
+			.ok_or(ServiceError::SelectChainRequired)?;
+
+		let babe_config = babe::BabeParams {
+			config: Config::get_or_compute(&*client)?,
+			keystore: service.keystore(),
+			client,
+			select_chain,
+			block_import,
+			env: proposer,
+			sync_oracle: service.network(),
+			inherent_data_providers: inherent_data_providers.clone(),
+			force_authoring: service.config().force_authoring,
+			time_source: babe_link,
+		};
+
+		let babe = start_babe(babe_config)?;
+		let select = babe.select(service.on_exit()).then(|_| Ok(()));
+
+		// the BABE authoring task is considered infallible, i.e. if it
+		// fails we take down the service with it.
+		service.spawn_essential_task(select);
+	}
+
+	let config = grandpa::Config {
+		// FIXME #1578 make this available through chainspec
+		gossip_duration: Duration::from_millis(333),
+		justification_period: 4096,
+		name: Some(service.config().name.clone()),
+		keystore: Some(service.keystore()),
+	};
+
+	match (service.config().roles.is_authority(), service.config().disable_grandpa) {
+		(false, false) => {
+			// start the lightweight GRANDPA observer
+			service.spawn_task(Box::new(grandpa::run_grandpa_observer(
+				config,
+				link_half,
+				service.network(),
+				service.on_exit(),
+			)?));
+		},
+		(true, false) => {
+			// start the full GRANDPA voter
+			let grandpa_config = grandpa::GrandpaParams {
+				config: config,
+				link: link_half,
+				network: service.network(),
+				inherent_data_providers: inherent_data_providers.clone(),
+				on_exit: service.on_exit(),
+				telemetry_on_connect: Some(service.telemetry_on_connect_stream()),
+			};
+
+			// the GRANDPA voter task is considered infallible, i.e.
+			// if it fails we take down the service with it.
+			service.spawn_essential_task(grandpa::run_grandpa_voter(grandpa_config)?);
+		},
+		(_, true) => {
+			grandpa::setup_disabled_grandpa(
+				service.client(),
+				&inherent_data_providers,
+				service.network(),
+			)?;
 		},
-		FinalityProofProvider = { |client: Arc<FullClient<Self>>| {
-			Ok(Some(Arc::new(GrandpaFinalityProofProvider::new(client.clone(), client)) as _))
-		}},
-		RpcExtensions = (),
 	}
+
+	Ok(service)
+}
+
+/// Builds a new service for a light client.
+pub fn new_light<C: Send + Default + 'static>(config: Configuration<C, GenesisConfig>)
+	-> Result<impl AbstractService, ServiceError>
+{
+	let inherent_data_providers = InherentDataProviders::new();
+
+	ServiceBuilder::new_light::<Block, RuntimeApi, Executor>(config)?
+		.with_select_chain(|_config, client| {
+			#[allow(deprecated)]
+			Ok(LongestChain::new(client.backend().clone()))
+		})?
+		.with_transaction_pool(|config, client|
+			Ok(TransactionPool::new(config, transaction_pool::ChainApi::new(client)))
+		)?
+		.with_import_queue_and_fprb(|_config, client, _select_chain, transaction_pool| {
+			#[allow(deprecated)]
+			let fetch_checker = client.backend().blockchain().fetcher()
+				.upgrade()
+				.map(|fetcher| fetcher.checker().clone())
+				.ok_or_else(|| "Trying to start light import queue without active fetch checker")?;
+			let block_import = grandpa::light_block_import::<_, _, _, RuntimeApi, _>(
+				client.clone(), Arc::new(fetch_checker), client.clone()
+			)?;
+
+			let finality_proof_import = block_import.clone();
+			let finality_proof_request_builder =
+				finality_proof_import.create_finality_proof_request_builder();
+
+			// FIXME: pruning task isn't started since light client doesn't do `AuthoritySetup`.
+			let (import_queue, ..) = import_queue(
+				Config::get_or_compute(&*client)?,
+				block_import,
+				None,
+				Some(Box::new(finality_proof_import)),
+				client.clone(),
+				client,
+				inherent_data_providers.clone(),
+				Some(transaction_pool)
+			)?;
+
+			Ok((import_queue, finality_proof_request_builder))
+		})?
+		.with_network_protocol(|_| Ok(NodeProtocol::new()))?
+		.with_finality_proof_provider(|client|
+			Ok(Arc::new(GrandpaFinalityProofProvider::new(client.clone(), client)) as _)
+		)?
+		.build()
 }
diff --git a/node/cli/Cargo.toml b/node/cli/Cargo.toml
index 7b4ebb0c5f32d..1f35f7b86b41c 100644
--- a/node/cli/Cargo.toml
+++ b/node/cli/Cargo.toml
@@ -11,7 +11,7 @@ log = "0.4"
 tokio = "0.1.7"
 futures = "0.1"
 exit-future = "0.1"
-jsonrpc-core = "13.0.0"
+jsonrpc-core = "13.1.0"
 cli = { package = "substrate-cli", path = "../../core/cli" }
 codec = { package = "parity-scale-codec", version = "1.0.0" }
 sr-io = { path = "../../core/sr-io" }
diff --git a/node/cli/src/chain_spec.rs b/node/cli/src/chain_spec.rs
index fca4c78b892ee..00bcb2577613d 100644
--- a/node/cli/src/chain_spec.rs
+++ b/node/cli/src/chain_spec.rs
@@ -30,7 +30,7 @@ use hex_literal::hex;
 use substrate_telemetry::TelemetryEndpoints;
 use grandpa_primitives::{AuthorityId as GrandpaId};
 use babe_primitives::{AuthorityId as BabeId};
-use im_online::AuthorityId as ImOnlineId;
+use im_online::sr25519::{AuthorityId as ImOnlineId};
 use sr_primitives::Perbill;
 
 const STAGING_TELEMETRY_URL: &str = "wss://telemetry.polkadot.io/submit/";
@@ -350,8 +350,8 @@ pub fn local_testnet_config() -> ChainSpec {
 #[cfg(test)]
 pub(crate) mod tests {
 	use super::*;
+	use crate::service::{new_full, new_light};
 	use service_test;
-	use crate::service::Factory;
 
 	fn local_testnet_genesis_instant_single() -> GenesisConfig {
 		testnet_genesis(
@@ -395,6 +395,10 @@ pub(crate) mod tests {
 	#[test]
 	#[ignore]
 	fn test_connectivity() {
-		service_test::connectivity::<Factory>(integration_test_config_with_two_authorities());
+		service_test::connectivity(
+			integration_test_config_with_two_authorities(),
+			|config| new_full(config),
+			|config| new_light(config),
+		);
 	}
 }
diff --git a/node/cli/src/lib.rs b/node/cli/src/lib.rs
index 4e3cfa7f01092..b7679be1764e0 100644
--- a/node/cli/src/lib.rs
+++ b/node/cli/src/lib.rs
@@ -21,14 +21,14 @@
 
 pub use cli::error;
 pub mod chain_spec;
+#[macro_use]
 mod service;
 mod factory_impl;
 
 use tokio::prelude::Future;
 use tokio::runtime::{Builder as RuntimeBuilder, Runtime};
 pub use cli::{VersionInfo, IntoExit, NoCustom, SharedParams, ExecutionStrategyParam};
-use substrate_service::{ServiceFactory, Roles as ServiceRoles};
-use std::ops::Deref;
+use substrate_service::{AbstractService, Roles as ServiceRoles};
 use log::info;
 use structopt::{StructOpt, clap::App};
 use cli::{AugmentClap, GetLogFilter, parse_and_prepare, ParseAndPrepare};
@@ -159,7 +159,8 @@ pub fn run<I, T, E>(args: I, exit: E, version: cli::VersionInfo) -> error::Resul
 	E: IntoExit,
 {
 	match parse_and_prepare::<CustomSubcommands, NoCustom, _>(&version, "substrate-node", args) {
-		ParseAndPrepare::Run(cmd) => cmd.run(load_spec, exit, |exit, _cli_args, _custom_args, config| {
+		ParseAndPrepare::Run(cmd) => cmd.run::<(), _, _, _, _>(load_spec, exit,
+		|exit, _cli_args, _custom_args, config| {
 			info!("{}", version.name);
 			info!("  version {}", config.full_version());
 			info!("  by Parity Technologies, 2017-2019");
@@ -171,23 +172,26 @@ pub fn run<I, T, E>(args: I, exit: E, version: cli::VersionInfo) -> error::Resul
 			match config.roles {
 				ServiceRoles::LIGHT => run_until_exit(
 					runtime,
-					service::Factory::new_light(config).map_err(|e| format!("{:?}", e))?,
+					service::new_light(config).map_err(|e| format!("{:?}", e))?,
 					exit
 				),
 				_ => run_until_exit(
 					runtime,
-					service::Factory::new_full(config).map_err(|e| format!("{:?}", e))?,
+					service::new_full(config).map_err(|e| format!("{:?}", e))?,
 					exit
 				),
 			}.map_err(|e| format!("{:?}", e))
 		}),
 		ParseAndPrepare::BuildSpec(cmd) => cmd.run(load_spec),
-		ParseAndPrepare::ExportBlocks(cmd) => cmd.run::<service::Factory, _, _>(load_spec, exit),
-		ParseAndPrepare::ImportBlocks(cmd) => cmd.run::<service::Factory, _, _>(load_spec, exit),
+		ParseAndPrepare::ExportBlocks(cmd) => cmd.run_with_builder::<(), _, _, _, _, _>(|config|
+			Ok(new_full_start!(config).0), load_spec, exit),
+		ParseAndPrepare::ImportBlocks(cmd) => cmd.run_with_builder::<(), _, _, _, _, _>(|config|
+			Ok(new_full_start!(config).0), load_spec, exit),
 		ParseAndPrepare::PurgeChain(cmd) => cmd.run(load_spec),
-		ParseAndPrepare::RevertChain(cmd) => cmd.run::<service::Factory, _>(load_spec),
+		ParseAndPrepare::RevertChain(cmd) => cmd.run_with_builder::<(), _, _, _, _>(|config|
+			Ok(new_full_start!(config).0), load_spec),
 		ParseAndPrepare::CustomCommand(CustomSubcommands::Factory(cli_args)) => {
-			let mut config = cli::create_config_with_db_path(
+			let mut config = cli::create_config_with_db_path::<(), _, _>(
 				load_spec,
 				&cli_args.shared_params,
 				&version,
@@ -209,9 +213,13 @@ pub fn run<I, T, E>(args: I, exit: E, version: cli::VersionInfo) -> error::Resul
 				cli_args.num,
 				cli_args.rounds,
 			);
-			transaction_factory::factory::<service::Factory, FactoryState<_>>(
+
+			let service_builder = new_full_start!(config).0;
+			transaction_factory::factory::<FactoryState<_>, _, _, _, _, _>(
 				factory_state,
-				config,
+				service_builder.client(),
+				service_builder.select_chain()
+					.expect("The select_chain is always initialized by new_full_start!; QED")
 			).map_err(|e| format!("Error in transaction factory: {}", e))?;
 
 			Ok(())
@@ -219,14 +227,13 @@ pub fn run<I, T, E>(args: I, exit: E, version: cli::VersionInfo) -> error::Resul
 	}
 }
 
-fn run_until_exit<T, C, E>(
+fn run_until_exit<T, E>(
 	mut runtime: Runtime,
 	service: T,
 	e: E,
-) -> error::Result<()> where
-	T: Deref<Target=substrate_service::Service<C>>,
-	T: Future<Item = (), Error = substrate_service::error::Error> + Send + 'static,
-	C: substrate_service::Components,
+) -> error::Result<()>
+where
+	T: AbstractService,
 	E: IntoExit,
 {
 	let (exit_send, exit) = exit_future::signal();
diff --git a/node/cli/src/service.rs b/node/cli/src/service.rs
index 7022d12d69a0f..c47e764c4294e 100644
--- a/node/cli/src/service.rs
+++ b/node/cli/src/service.rs
@@ -16,271 +16,240 @@
 
 #![warn(unused_extern_crates)]
 
-//! Service and ServiceFactory implementation. Specialized wrapper over substrate service.
+//! Service implementation. Specialized wrapper over substrate service.
 
 use std::sync::Arc;
-use std::time::Duration;
 
-use babe::{import_queue, start_babe, BabeImportQueue, Config};
+use babe::{import_queue, Config};
 use client::{self, LongestChain};
 use grandpa::{self, FinalityProofProvider as GrandpaFinalityProofProvider};
 use node_executor;
-use futures::prelude::*;
 use node_primitives::Block;
 use node_runtime::{GenesisConfig, RuntimeApi};
 use substrate_service::{
-	FactoryFullConfiguration, LightComponents, FullComponents, FullBackend,
-	FullClient, LightClient, LightBackend, FullExecutor, LightExecutor,
-	error::{Error as ServiceError},
+	AbstractService, ServiceBuilder, config::Configuration, error::{Error as ServiceError},
 };
 use transaction_pool::{self, txpool::{Pool as TransactionPool}};
 use inherents::InherentDataProviders;
 use network::construct_simple_protocol;
-use substrate_service::construct_service_factory;
-use substrate_service::TelemetryOnConnect;
 
 construct_simple_protocol! {
 	/// Demo protocol attachment for substrate.
 	pub struct NodeProtocol where Block = Block { }
 }
 
-type BabeBlockImportForService<F> = babe::BabeBlockImport<
-	FullBackend<F>,
-	FullExecutor<F>,
-	<F as crate::ServiceFactory>::Block,
-	grandpa::BlockImportForService<F>,
-	<F as crate::ServiceFactory>::RuntimeApi,
-	client::Client<
-		FullBackend<F>,
-		FullExecutor<F>,
-		<F as crate::ServiceFactory>::Block,
-		<F as crate::ServiceFactory>::RuntimeApi
-	>,
->;
-
-/// Node specific configuration
-pub struct NodeConfig<F: substrate_service::ServiceFactory> {
-	/// GRANDPA and BABE connection to import block.
-	// FIXME #1134 rather than putting this on the config, let's have an actual intermediate setup state
-	pub import_setup: Option<(
-		BabeBlockImportForService<F>,
-		grandpa::LinkHalfForService<F>,
-		babe::BabeLink,
-	)>,
-	/// Tasks that were created by previous setup steps and should be spawned.
-	pub tasks_to_spawn: Option<Vec<Box<dyn Future<Item = (), Error = ()> + Send>>>,
-	inherent_data_providers: InherentDataProviders,
-}
-
-impl<F> Default for NodeConfig<F> where F: substrate_service::ServiceFactory {
-	fn default() -> NodeConfig<F> {
-		NodeConfig {
-			import_setup: None,
-			inherent_data_providers: InherentDataProviders::new(),
-			tasks_to_spawn: None,
-		}
-	}
-}
-
-construct_service_factory! {
-	struct Factory {
-		Block = Block,
-		RuntimeApi = RuntimeApi,
-		NetworkProtocol = NodeProtocol { |config| Ok(NodeProtocol::new()) },
-		RuntimeDispatch = node_executor::Executor,
-		FullTransactionPoolApi =
-			transaction_pool::ChainApi<
-				client::Client<FullBackend<Self>, FullExecutor<Self>, Block, RuntimeApi>,
-				Block
-			> {
-				|config, client|
-					Ok(TransactionPool::new(config, transaction_pool::ChainApi::new(client)))
-			},
-		LightTransactionPoolApi =
-			transaction_pool::ChainApi<
-				client::Client<LightBackend<Self>, LightExecutor<Self>, Block, RuntimeApi>,
-				Block
-			> {
-				|config, client|
-					Ok(TransactionPool::new(config, transaction_pool::ChainApi::new(client)))
-			},
-		Genesis = GenesisConfig,
-		Configuration = NodeConfig<Self>,
-		FullService = FullComponents<Self> {
-			|config: FactoryFullConfiguration<Self>| FullComponents::<Factory>::new(config)
-		},
-		AuthoritySetup = {
-			|mut service: Self::FullService| {
-				let (block_import, link_half, babe_link) =
-					service.config_mut().custom.import_setup.take()
-						.expect("Link Half and Block Import are present for Full Services or setup failed before. qed");
-
-				// spawn any futures that were created in the previous setup steps
-				if let Some(tasks) = service.config_mut().custom.tasks_to_spawn.take() {
-					for task in tasks {
-						service.spawn_task(
-							task.select(service.on_exit())
-								.map(|_| ())
-								.map_err(|_| ())
-						);
-					}
-				}
-
-				if service.config().roles.is_authority() {
-					let proposer = substrate_basic_authorship::ProposerFactory {
-						client: service.client(),
-						transaction_pool: service.transaction_pool(),
-					};
-
-					let client = service.client();
-					let select_chain = service.select_chain()
-						.ok_or(ServiceError::SelectChainRequired)?;
-
-					let babe_config = babe::BabeParams {
-						config: Config::get_or_compute(&*client)?,
-						keystore: service.keystore(),
-						client,
-						select_chain,
-						block_import,
-						env: proposer,
-						sync_oracle: service.network(),
-						inherent_data_providers: service.config()
-							.custom.inherent_data_providers.clone(),
-						force_authoring: service.config().force_authoring,
-						time_source: babe_link,
-					};
-
-					let babe = start_babe(babe_config)?;
-					let select = babe.select(service.on_exit()).then(|_| Ok(()));
-
-					// the BABE authoring task is considered infallible, i.e. if it
-					// fails we take down the service with it.
-					service.spawn_essential_task(select);
-				}
-
-				let config = grandpa::Config {
-					// FIXME #1578 make this available through chainspec
-					gossip_duration: Duration::from_millis(333),
-					justification_period: 4096,
-					name: Some(service.config().name.clone()),
-					keystore: Some(service.keystore()),
-				};
-
-				match (service.config().roles.is_authority(), service.config().disable_grandpa) {
-					(false, false) => {
-						// start the lightweight GRANDPA observer
-						service.spawn_task(Box::new(grandpa::run_grandpa_observer(
-							config,
-							link_half,
-							service.network(),
-							service.on_exit(),
-						)?));
-					},
-					(true, false) => {
-						// start the full GRANDPA voter
-						let telemetry_on_connect = TelemetryOnConnect {
-							telemetry_connection_sinks: service.telemetry_on_connect_stream(),
-						};
-						let grandpa_config = grandpa::GrandpaParams {
-							config: config,
-							link: link_half,
-							network: service.network(),
-							inherent_data_providers:
-								service.config().custom.inherent_data_providers.clone(),
-							on_exit: service.on_exit(),
-							telemetry_on_connect: Some(telemetry_on_connect),
-						};
-
-						// the GRANDPA voter task is considered infallible, i.e.
-						// if it fails we take down the service with it.
-						service.spawn_essential_task(grandpa::run_grandpa_voter(grandpa_config)?);
-					},
-					(_, true) => {
-						grandpa::setup_disabled_grandpa(
-							service.client(),
-							&service.config().custom.inherent_data_providers,
-							service.network(),
-						)?;
-					},
-				}
-
-				Ok(service)
-			}
-		},
-		LightService = LightComponents<Self>
-			{ |config| <LightComponents<Factory>>::new(config) },
-		FullImportQueue = BabeImportQueue<Self::Block>
-			{
-				|
-					config: &mut FactoryFullConfiguration<Self>,
-					client: Arc<FullClient<Self>>,
-					select_chain: Self::SelectChain,
-					transaction_pool: Option<Arc<TransactionPool<Self::FullTransactionPoolApi>>>,
-				|
-			{
+/// Starts a `ServiceBuilder` for a full service.
+///
+/// Use this macro if you don't actually need the full service, but just the builder in order to
+/// be able to perform chain operations.
+macro_rules! new_full_start {
+	($config:expr) => {{
+		let mut import_setup = None;
+		let inherent_data_providers = inherents::InherentDataProviders::new();
+		let mut tasks_to_spawn = None;
+
+		let builder = substrate_service::ServiceBuilder::new_full::<
+			node_primitives::Block, node_runtime::RuntimeApi, node_executor::Executor
+		>($config)?
+			.with_select_chain(|_config, client| {
+				#[allow(deprecated)]
+				Ok(client::LongestChain::new(client.backend().clone()))
+			})?
+			.with_transaction_pool(|config, client|
+				Ok(transaction_pool::txpool::Pool::new(config, transaction_pool::ChainApi::new(client)))
+			)?
+			.with_import_queue(|_config, client, mut select_chain, transaction_pool| {
+				let select_chain = select_chain.take()
+					.ok_or_else(|| substrate_service::Error::SelectChainRequired)?;
 				let (block_import, link_half) =
-					grandpa::block_import::<_, _, _, RuntimeApi, FullClient<Self>, _>(
+					grandpa::block_import::<_, _, _, node_runtime::RuntimeApi, _, _>(
 						client.clone(), client.clone(), select_chain
 					)?;
 				let justification_import = block_import.clone();
 
-				let (import_queue, babe_link, babe_block_import, pruning_task) = import_queue(
-					Config::get_or_compute(&*client)?,
+				let (import_queue, babe_link, babe_block_import, pruning_task) = babe::import_queue(
+					babe::Config::get_or_compute(&*client)?,
 					block_import,
 					Some(Box::new(justification_import)),
 					None,
 					client.clone(),
 					client,
-					config.custom.inherent_data_providers.clone(),
-					transaction_pool,
+					inherent_data_providers.clone(),
+					Some(transaction_pool)
 				)?;
 
-				config.custom.import_setup = Some((babe_block_import.clone(), link_half, babe_link));
-				config.custom.tasks_to_spawn = Some(vec![Box::new(pruning_task)]);
+				import_setup = Some((babe_block_import.clone(), link_half, babe_link));
+				tasks_to_spawn = Some(vec![Box::new(pruning_task)]);
 
 				Ok(import_queue)
-			}},
-		LightImportQueue = BabeImportQueue<Self::Block>
-			{ |config: &FactoryFullConfiguration<Self>, client: Arc<LightClient<Self>>| {
-				#[allow(deprecated)]
-				let fetch_checker = client.backend().blockchain().fetcher()
-					.upgrade()
-					.map(|fetcher| fetcher.checker().clone())
-					.ok_or_else(|| "Trying to start light import queue without active fetch checker")?;
-				let block_import = grandpa::light_block_import::<_, _, _, RuntimeApi, LightClient<Self>>(
-					client.clone(), Arc::new(fetch_checker), client.clone()
-				)?;
+			})?
+			.with_rpc_extensions(|client, pool| {
+				use node_rpc::accounts::{Accounts, AccountsApi};
+
+				let mut io = jsonrpc_core::IoHandler::<substrate_service::RpcMetadata>::default();
+				io.extend_with(
+					AccountsApi::to_delegate(Accounts::new(client, pool))
+				);
+				io
+			})?;
+		
+		(builder, import_setup, inherent_data_providers, tasks_to_spawn)
+	}}
+}
 
-				let finality_proof_import = block_import.clone();
-				let finality_proof_request_builder =
-					finality_proof_import.create_finality_proof_request_builder();
+/// Creates a full service from the configuration.
+///
+/// We need to use a macro because the test suit doesn't work with an opaque service. It expects
+/// concrete types instead.
+macro_rules! new_full {
+	($config:expr) => {{
+		use futures::Future;
+
+		let (builder, mut import_setup, inherent_data_providers, mut tasks_to_spawn) = new_full_start!($config);
+
+		let service = builder.with_network_protocol(|_| Ok(crate::service::NodeProtocol::new()))?
+			.with_finality_proof_provider(|client|
+				Ok(Arc::new(grandpa::FinalityProofProvider::new(client.clone(), client)) as _)
+			)?
+			.build()?;
+
+		let (block_import, link_half, babe_link) = import_setup.take()
+				.expect("Link Half and Block Import are present for Full Services or setup failed before. qed");
+
+		// spawn any futures that were created in the previous setup steps
+		if let Some(tasks) = tasks_to_spawn.take() {
+			for task in tasks {
+				service.spawn_task(
+					task.select(service.on_exit())
+						.map(|_| ())
+						.map_err(|_| ())
+				);
+			}
+		}
 
-				// FIXME: pruning task isn't started since light client doesn't do `AuthoritySetup`.
-				let (import_queue, ..) = import_queue::<_, _, _, _, _, _, TransactionPool<Self::FullTransactionPoolApi>>(
-					Config::get_or_compute(&*client)?,
-					block_import,
-					None,
-					Some(Box::new(finality_proof_import)),
-					client.clone(),
-					client,
-					config.custom.inherent_data_providers.clone(),
-					None,
+		if service.config().roles.is_authority() {
+			let proposer = substrate_basic_authorship::ProposerFactory {
+				client: service.client(),
+				transaction_pool: service.transaction_pool(),
+			};
+
+			let client = service.client();
+			let select_chain = service.select_chain()
+				.ok_or(substrate_service::Error::SelectChainRequired)?;
+
+			let babe_config = babe::BabeParams {
+				config: babe::Config::get_or_compute(&*client)?,
+				keystore: service.keystore(),
+				client,
+				select_chain,
+				block_import,
+				env: proposer,
+				sync_oracle: service.network(),
+				inherent_data_providers: inherent_data_providers.clone(),
+				force_authoring: service.config().force_authoring,
+				time_source: babe_link,
+			};
+
+			let babe = babe::start_babe(babe_config)?;
+			let select = babe.select(service.on_exit()).then(|_| Ok(()));
+			service.spawn_task(Box::new(select));
+		}
+
+		let config = grandpa::Config {
+			// FIXME #1578 make this available through chainspec
+			gossip_duration: std::time::Duration::from_millis(333),
+			justification_period: 4096,
+			name: Some(service.config().name.clone()),
+			keystore: Some(service.keystore()),
+		};
+
+		match (service.config().roles.is_authority(), service.config().disable_grandpa) {
+			(false, false) => {
+				// start the lightweight GRANDPA observer
+				service.spawn_task(Box::new(grandpa::run_grandpa_observer(
+					config,
+					link_half,
+					service.network(),
+					service.on_exit(),
+				)?));
+			},
+			(true, false) => {
+				// start the full GRANDPA voter
+				let grandpa_config = grandpa::GrandpaParams {
+					config: config,
+					link: link_half,
+					network: service.network(),
+					inherent_data_providers: inherent_data_providers.clone(),
+					on_exit: service.on_exit(),
+					telemetry_on_connect: Some(service.telemetry_on_connect_stream()),
+				};
+				service.spawn_task(Box::new(grandpa::run_grandpa_voter(grandpa_config)?));
+			},
+			(_, true) => {
+				grandpa::setup_disabled_grandpa(
+					service.client(),
+					&inherent_data_providers,
+					service.network(),
 				)?;
+			},
+		}
 
-				Ok((import_queue, finality_proof_request_builder))
-			}},
-		SelectChain = LongestChain<FullBackend<Self>, Self::Block>
-			{ |config: &FactoryFullConfiguration<Self>, client: Arc<FullClient<Self>>| {
-				#[allow(deprecated)]
-				Ok(LongestChain::new(client.backend().clone()))
-			}
-		},
-		FinalityProofProvider = { |client: Arc<FullClient<Self>>| {
-			Ok(Some(Arc::new(GrandpaFinalityProofProvider::new(client.clone(), client)) as _))
-		}},
+		Ok((service, inherent_data_providers))
+	}}
+}
 
-		RpcExtensions = jsonrpc_core::IoHandler<substrate_rpc::Metadata>
-		{ |client, pool| {
+/// Builds a new service for a full client.
+pub fn new_full<C: Send + Default + 'static>(config: Configuration<C, GenesisConfig>)
+-> Result<impl AbstractService, ServiceError> {
+	new_full!(config).map(|(service, _)| service)
+}
+
+/// Builds a new service for a light client.
+pub fn new_light<C: Send + Default + 'static>(config: Configuration<C, GenesisConfig>)
+-> Result<impl AbstractService, ServiceError> {
+	let inherent_data_providers = InherentDataProviders::new();
+
+	ServiceBuilder::new_light::<Block, RuntimeApi, node_executor::Executor>(config)?
+		.with_select_chain(|_config, client| {
+			#[allow(deprecated)]
+			Ok(LongestChain::new(client.backend().clone()))
+		})?
+		.with_transaction_pool(|config, client|
+			Ok(TransactionPool::new(config, transaction_pool::ChainApi::new(client)))
+		)?
+		.with_import_queue_and_fprb(|_config, client, _select_chain, transaction_pool| {
+			#[allow(deprecated)]
+			let fetch_checker = client.backend().blockchain().fetcher()
+				.upgrade()
+				.map(|fetcher| fetcher.checker().clone())
+				.ok_or_else(|| "Trying to start light import queue without active fetch checker")?;
+			let block_import = grandpa::light_block_import::<_, _, _, RuntimeApi, _>(
+				client.clone(), Arc::new(fetch_checker), client.clone()
+			)?;
+
+			let finality_proof_import = block_import.clone();
+			let finality_proof_request_builder =
+				finality_proof_import.create_finality_proof_request_builder();
+
+			// FIXME: pruning task isn't started since light client doesn't do `AuthoritySetup`.
+			let (import_queue, ..) = import_queue(
+				Config::get_or_compute(&*client)?,
+				block_import,
+				None,
+				Some(Box::new(finality_proof_import)),
+				client.clone(),
+				client,
+				inherent_data_providers.clone(),
+				Some(transaction_pool)
+			)?;
+
+			Ok((import_queue, finality_proof_request_builder))
+		})?
+		.with_network_protocol(|_| Ok(NodeProtocol::new()))?
+		.with_finality_proof_provider(|client|
+			Ok(Arc::new(GrandpaFinalityProofProvider::new(client.clone(), client)) as _)
+		)?
+		.with_rpc_extensions(|client, pool| {
 			use node_rpc::accounts::{Accounts, AccountsApi};
 
 			let mut io = jsonrpc_core::IoHandler::default();
@@ -288,11 +257,10 @@ construct_service_factory! {
 				AccountsApi::to_delegate(Accounts::new(client, pool))
 			);
 			io
-		}},
-	}
+		})?
+		.build()
 }
 
-
 #[cfg(test)]
 mod tests {
 	use std::sync::Arc;
@@ -312,9 +280,8 @@ mod tests {
 	use timestamp;
 	use finality_tracker;
 	use keyring::AccountKeyring;
-	use substrate_service::ServiceFactory;
-	use service_test::SyncService;
-	use crate::service::Factory;
+	use substrate_service::AbstractService;
+	use crate::service::{new_full, new_light};
 
 	#[cfg(feature = "rhd")]
 	fn test_sync() {
@@ -369,8 +336,10 @@ mod tests {
 			let v: Vec<u8> = Decode::decode(&mut xt.as_slice()).unwrap();
 			OpaqueExtrinsic(v)
 		};
-		service_test::sync::<Factory, _, _>(
+		service_test::sync(
 			chain_spec::integration_test_config(),
+			|config| new_full(config),
+			|config| new_light(config),
 			block_factory,
 			extrinsic_factory,
 		);
@@ -387,130 +356,127 @@ mod tests {
 
 		let chain_spec = crate::chain_spec::tests::integration_test_config_with_single_authority();
 
+		// For the block factory
 		let mut slot_num = 1u64;
-		let block_factory = |service: &SyncService<<Factory as ServiceFactory>::FullService>| {
-			let service = service.get();
-			let mut inherent_data = service
-				.config()
-				.custom
-				.inherent_data_providers
-				.create_inherent_data()
-				.expect("Creates inherent data.");
-			inherent_data.replace_data(finality_tracker::INHERENT_IDENTIFIER, &1u64);
-
-			let parent_id = BlockId::number(service.client().info().chain.best_number);
-			let parent_header = service.client().header(&parent_id).unwrap().unwrap();
-			let mut proposer_factory = substrate_basic_authorship::ProposerFactory {
-				client: service.client(),
-				transaction_pool: service.transaction_pool(),
-			};
-
-			let mut digest = Digest::<H256>::default();
-
-			// even though there's only one authority some slots might be empty,
-			// so we must keep trying the next slots until we can claim one.
-			let babe_pre_digest = loop {
-				inherent_data.replace_data(timestamp::INHERENT_IDENTIFIER, &(slot_num * SLOT_DURATION));
-				if let Some(babe_pre_digest) = babe::test_helpers::claim_slot(
-					slot_num,
-					&parent_header,
-					&*service.client(),
-					(278, 1000),
-					&keystore,
-				) {
-					break babe_pre_digest;
-				}
-
-				slot_num += 1;
-			};
-
-			digest.push(<DigestItem as CompatibleDigestItem>::babe_pre_digest(babe_pre_digest));
-
-			let mut proposer = proposer_factory.init(&parent_header).unwrap();
-			let new_block = futures03::executor::block_on(proposer.propose(
-				inherent_data,
-				digest,
-				std::time::Duration::from_secs(1),
-			)).expect("Error making test block");
-
-			let (new_header, new_body) = new_block.deconstruct();
-			let pre_hash = new_header.hash();
-			// sign the pre-sealed hash of the block and then
-			// add it to a digest item.
-			let to_sign = pre_hash.encode();
-			let signature = alice.sign(&to_sign[..]);
-			let item = <DigestItem as CompatibleDigestItem>::babe_seal(
-				signature.into(),
-			);
-			slot_num += 1;
-
-			BlockImportParams {
-				origin: BlockOrigin::File,
-				header: new_header,
-				justification: None,
-				post_digests: vec![item],
-				body: Some(new_body),
-				finalized: true,
-				auxiliary: Vec::new(),
-				fork_choice: ForkChoiceStrategy::LongestChain,
-			}
-		};
 
+		// For the extrinsics factory
 		let bob = Arc::new(AccountKeyring::Bob.pair());
 		let charlie = Arc::new(AccountKeyring::Charlie.pair());
-
 		let mut index = 0;
-		let extrinsic_factory = |service: &SyncService<<Factory as ServiceFactory>::FullService>| {
-			let amount = 5 * CENTS;
-			let to = AddressPublic::from_raw(bob.public().0);
-			let from = AddressPublic::from_raw(charlie.public().0);
-			let genesis_hash = service.get().client().block_hash(0).unwrap().unwrap();
-			let best_block_id = BlockId::number(service.get().client().info().chain.best_number);
-			let version = service.get().client().runtime_version_at(&best_block_id).unwrap().spec_version;
-			let signer = charlie.clone();
-
-			let function = Call::Balances(BalancesCall::transfer(to.into(), amount));
-
-			let check_version = system::CheckVersion::new();
-			let check_genesis = system::CheckGenesis::new();
-			let check_era = system::CheckEra::from(Era::Immortal);
-			let check_nonce = system::CheckNonce::from(index);
-			let check_weight = system::CheckWeight::new();
-			let take_fees = balances::TakeFees::from(0);
-			let extra = (check_version, check_genesis, check_era, check_nonce, check_weight, take_fees);
-
-			let raw_payload = (function, extra.clone(), version, genesis_hash, genesis_hash);
-			let signature = raw_payload.using_encoded(|payload| if payload.len() > 256 {
-				signer.sign(&blake2_256(payload)[..])
-			} else {
-				signer.sign(payload)
-			});
-			let xt = UncheckedExtrinsic::new_signed(
-				raw_payload.0,
-				from.into(),
-				signature.into(),
-				extra,
-			).encode();
-			let v: Vec<u8> = Decode::decode(&mut xt.as_slice()).unwrap();
 
-			index += 1;
-			OpaqueExtrinsic(v)
-		};
-
-		service_test::sync::<Factory, _, _>(
+		service_test::sync(
 			chain_spec,
-			block_factory,
-			extrinsic_factory,
+			|config| new_full!(config),
+			|config| new_light(config),
+			|service, inherent_data_providers| {
+				let mut inherent_data = inherent_data_providers
+					.create_inherent_data()
+					.expect("Creates inherent data.");
+				inherent_data.replace_data(finality_tracker::INHERENT_IDENTIFIER, &1u64);
+
+				let parent_id = BlockId::number(service.client().info().chain.best_number);
+				let parent_header = service.client().header(&parent_id).unwrap().unwrap();
+				let mut proposer_factory = substrate_basic_authorship::ProposerFactory {
+					client: service.client(),
+					transaction_pool: service.transaction_pool(),
+				};
+
+				let mut digest = Digest::<H256>::default();
+
+				// even though there's only one authority some slots might be empty,
+				// so we must keep trying the next slots until we can claim one.
+				let babe_pre_digest = loop {
+					inherent_data.replace_data(timestamp::INHERENT_IDENTIFIER, &(slot_num * SLOT_DURATION));
+					if let Some(babe_pre_digest) = babe::test_helpers::claim_slot(
+						slot_num,
+						&parent_header,
+						&*service.client(),
+						(278, 1000),
+						&keystore,
+					) {
+						break babe_pre_digest;
+					}
+
+					slot_num += 1;
+				};
+
+				digest.push(<DigestItem as CompatibleDigestItem>::babe_pre_digest(babe_pre_digest));
+
+				let mut proposer = proposer_factory.init(&parent_header).unwrap();
+				let new_block = futures03::executor::block_on(proposer.propose(
+					inherent_data,
+					digest,
+					std::time::Duration::from_secs(1),
+				)).expect("Error making test block");
+
+				let (new_header, new_body) = new_block.deconstruct();
+				let pre_hash = new_header.hash();
+				// sign the pre-sealed hash of the block and then
+				// add it to a digest item.
+				let to_sign = pre_hash.encode();
+				let signature = alice.sign(&to_sign[..]);
+				let item = <DigestItem as CompatibleDigestItem>::babe_seal(
+					signature.into(),
+				);
+				slot_num += 1;
+
+				BlockImportParams {
+					origin: BlockOrigin::File,
+					header: new_header,
+					justification: None,
+					post_digests: vec![item],
+					body: Some(new_body),
+					finalized: true,
+					auxiliary: Vec::new(),
+					fork_choice: ForkChoiceStrategy::LongestChain,
+				}
+			},
+			|service, _| {
+				let amount = 5 * CENTS;
+				let to = AddressPublic::from_raw(bob.public().0);
+				let from = AddressPublic::from_raw(charlie.public().0);
+				let genesis_hash = service.client().block_hash(0).unwrap().unwrap();
+				let best_block_id = BlockId::number(service.client().info().chain.best_number);
+				let version = service.client().runtime_version_at(&best_block_id).unwrap().spec_version;
+				let signer = charlie.clone();
+
+				let function = Call::Balances(BalancesCall::transfer(to.into(), amount));
+
+				let check_version = system::CheckVersion::new();
+				let check_genesis = system::CheckGenesis::new();
+				let check_era = system::CheckEra::from(Era::Immortal);
+				let check_nonce = system::CheckNonce::from(index);
+				let check_weight = system::CheckWeight::new();
+				let take_fees = balances::TakeFees::from(0);
+				let extra = (check_version, check_genesis, check_era, check_nonce, check_weight, take_fees);
+
+				let raw_payload = (function, extra.clone(), version, genesis_hash, genesis_hash);
+				let signature = raw_payload.using_encoded(|payload| if payload.len() > 256 {
+					signer.sign(&blake2_256(payload)[..])
+				} else {
+					signer.sign(payload)
+				});
+				let xt = UncheckedExtrinsic::new_signed(
+					raw_payload.0,
+					from.into(),
+					signature.into(),
+					extra,
+				).encode();
+				let v: Vec<u8> = Decode::decode(&mut xt.as_slice()).unwrap();
+
+				index += 1;
+				OpaqueExtrinsic(v)
+			},
 		);
 	}
 
 	#[test]
 	#[ignore]
 	fn test_consensus() {
-		use super::Factory;
-
-		service_test::consensus::<Factory>(
+		service_test::consensus(
 			crate::chain_spec::tests::integration_test_config_with_two_authorities(),
+			|config| new_full(config),
+			|config| new_light(config),
 			vec![
 				"//Alice".into(),
 				"//Bob".into(),
diff --git a/node/executor/src/lib.rs b/node/executor/src/lib.rs
index 874c5a1b6db1c..eba744f62adfc 100644
--- a/node/executor/src/lib.rs
+++ b/node/executor/src/lib.rs
@@ -30,8 +30,7 @@ use substrate_executor::native_executor_instance;
 native_executor_instance!(
 	pub Executor,
 	node_runtime::api::dispatch,
-	node_runtime::native_version,
-	node_runtime::WASM_BINARY
+	node_runtime::native_version
 );
 
 #[cfg(test)]
diff --git a/node/rpc-client/Cargo.toml b/node/rpc-client/Cargo.toml
index bc492bc003394..b98df224dfcf1 100644
--- a/node/rpc-client/Cargo.toml
+++ b/node/rpc-client/Cargo.toml
@@ -8,7 +8,7 @@ edition = "2018"
 env_logger = "0.6"
 futures = "0.1.26"
 hyper = "0.12"
-jsonrpc-core-client = { version = "13.0.0", features = ["http", "ws"] }
+jsonrpc-core-client = { version = "13.1.0", features = ["http", "ws"] }
 log = "0.4"
 node-primitives = { path = "../primitives" }
 substrate-rpc = { path = "../../core/rpc", version = "2.0.0" }
diff --git a/node/rpc/Cargo.toml b/node/rpc/Cargo.toml
index 6042380c8379f..55371daad6b0f 100644
--- a/node/rpc/Cargo.toml
+++ b/node/rpc/Cargo.toml
@@ -6,10 +6,10 @@ edition = "2018"
 
 [dependencies]
 client = { package = "substrate-client", path = "../../core/client" }
-jsonrpc-core = "13.0.0"
-jsonrpc-core-client = "13.0.0"
-jsonrpc-derive = "13.0.0"
-jsonrpc-pubsub = "13.0.0"
+jsonrpc-core = "13.1.0"
+jsonrpc-core-client = "13.1.0"
+jsonrpc-derive = "13.1.0"
+jsonrpc-pubsub = "13.1.0"
 keyring = { package = "substrate-keyring", path = "../../core/keyring" }
 log = "0.4"
 node-primitives = { path = "../primitives" }
diff --git a/node/runtime/src/lib.rs b/node/runtime/src/lib.rs
index e80d5fa83ab38..d23e3bb457542 100644
--- a/node/runtime/src/lib.rs
+++ b/node/runtime/src/lib.rs
@@ -47,8 +47,7 @@ use elections::VoteIndex;
 use version::NativeVersion;
 use primitives::OpaqueMetadata;
 use grandpa::{AuthorityId as GrandpaId, AuthorityWeight as GrandpaWeight};
-use im_online::{AuthorityId as ImOnlineId};
-use finality_tracker::{DEFAULT_REPORT_LATENCY, DEFAULT_WINDOW_SIZE};
+use im_online::sr25519::{AuthorityId as ImOnlineId};
 
 #[cfg(any(feature = "std", test))]
 pub use sr_primitives::BuildStorage;
@@ -80,8 +79,8 @@ pub const VERSION: RuntimeVersion = RuntimeVersion {
 	// and set impl_version to equal spec_version. If only runtime
 	// implementation changes and behavior does not, then leave spec_version as
 	// is and increment impl_version.
-	spec_version: 149,
-	impl_version: 149,
+	spec_version: 154,
+	impl_version: 154,
 	apis: RUNTIME_API_VERSIONS,
 };
 
@@ -394,6 +393,7 @@ impl sudo::Trait for Runtime {
 }
 
 impl im_online::Trait for Runtime {
+	type AuthorityId = ImOnlineId;
 	type Call = Call;
 	type Event = Event;
 	type UncheckedExtrinsic = UncheckedExtrinsic;
@@ -414,8 +414,8 @@ impl grandpa::Trait for Runtime {
 }
 
 parameter_types! {
-	pub const WindowSize: BlockNumber = DEFAULT_WINDOW_SIZE.into();
-	pub const ReportLatency: BlockNumber = DEFAULT_REPORT_LATENCY.into();
+	pub const WindowSize: BlockNumber = 101;
+	pub const ReportLatency: BlockNumber = 1000;
 }
 
 impl finality_tracker::Trait for Runtime {
@@ -448,8 +448,8 @@ construct_runtime!(
 		Treasury: treasury::{Module, Call, Storage, Event<T>},
 		Contracts: contracts,
 		Sudo: sudo,
-		ImOnline: im_online::{Module, Call, Storage, Event, ValidateUnsigned, Config},
-		AuthorityDiscovery: authority_discovery::{Module, Call, Config},
+		ImOnline: im_online::{Module, Call, Storage, Event<T>, ValidateUnsigned, Config<T>},
+		AuthorityDiscovery: authority_discovery::{Module, Call, Config<T>},
 		Offences: offences::{Module, Call, Storage, Event},
 	}
 );
@@ -579,19 +579,19 @@ impl_runtime_apis! {
 		}
 	}
 
-	impl authority_discovery_primitives::AuthorityDiscoveryApi<Block, im_online::AuthorityId> for Runtime {
-		fn authority_id() -> Option<im_online::AuthorityId> {
+	impl authority_discovery_primitives::AuthorityDiscoveryApi<Block, ImOnlineId> for Runtime {
+		fn authority_id() -> Option<ImOnlineId> {
 			AuthorityDiscovery::authority_id()
 		}
-		fn authorities() -> Vec<im_online::AuthorityId> {
+		fn authorities() -> Vec<ImOnlineId> {
 			AuthorityDiscovery::authorities()
 		}
 
-		fn sign(payload: Vec<u8>, authority_id: im_online::AuthorityId) -> Option<Vec<u8>> {
+		fn sign(payload: Vec<u8>, authority_id: ImOnlineId) -> Option<Vec<u8>> {
 			AuthorityDiscovery::sign(payload, authority_id)
 		}
 
-		fn verify(payload: Vec<u8>, signature: Vec<u8>, public_key: im_online::AuthorityId) -> bool {
+		fn verify(payload: Vec<u8>, signature: Vec<u8>, public_key: ImOnlineId) -> bool {
 			AuthorityDiscovery::verify(payload, signature, public_key)
 		}
 	}
diff --git a/scripts/node-template-release/src/main.rs b/scripts/node-template-release/src/main.rs
index 4036104f6030a..e1db5af649748 100644
--- a/scripts/node-template-release/src/main.rs
+++ b/scripts/node-template-release/src/main.rs
@@ -117,8 +117,15 @@ fn replace_path_dependencies_with_git(cargo_toml_path: &Path, commit_id: &str, c
 	cargo_toml.insert("dependencies".into(), dependencies.into());
 }
 
-/// Add `profile.release` = `panic = unwind` to the given `Cargo.toml`
-fn cargo_toml_add_profile_release(cargo_toml: &mut CargoToml) {
+/// Update the top level (workspace) `Cargo.toml` file.
+///
+/// - Adds `profile.release` = `panic = unwind`
+/// - Adds `workspace` definition
+fn update_top_level_cargo_toml(
+	cargo_toml: &mut CargoToml,
+	workspace_members: Vec<&PathBuf>,
+	node_template_path: &Path,
+) {
 	let mut panic_unwind = toml::value::Table::new();
 	panic_unwind.insert("panic".into(), "unwind".into());
 
@@ -126,6 +133,24 @@ fn cargo_toml_add_profile_release(cargo_toml: &mut CargoToml) {
 	profile.insert("release".into(), panic_unwind.into());
 
 	cargo_toml.insert("profile".into(), profile.into());
+
+	let members = workspace_members.iter()
+		.map(|p|
+			p.strip_prefix(node_template_path)
+				.expect("Workspace member is a child of the node template path!")
+				.parent()
+				// We get the `Cargo.toml` paths as workspace members, but for the `members` field
+				// we just need the path.
+				.expect("The given path ends with `Cargo.toml` as file name!")
+				.display()
+				.to_string()
+		)
+		.collect::<Vec<_>>();
+
+	let mut members_section = toml::value::Table::new();
+	members_section.insert("members".into(), members.into());
+
+	cargo_toml.insert("workspace".into(), members_section.into());
 }
 
 fn write_cargo_toml(path: &Path, cargo_toml: CargoToml) {
@@ -137,10 +162,24 @@ fn write_cargo_toml(path: &Path, cargo_toml: CargoToml) {
 /// Build and test the generated node-template
 fn build_and_test(path: &Path, cargo_tomls: &[PathBuf]) {
 	// Build node
-	assert!(Command::new("cargo").args(&["build", "--all"]).current_dir(path).status().expect("Compiles node").success());
+	assert!(
+		Command::new("cargo")
+			.args(&["build", "--all"])
+			.current_dir(path)
+			.status()
+			.expect("Compiles node")
+			.success()
+	);
 
 	// Test node
-	assert!(Command::new("cargo").args(&["test", "--all"]).current_dir(path).status().expect("Tests node").success());
+	assert!(
+		Command::new("cargo")
+			.args(&["test", "--all"])
+			.current_dir(path)
+			.status()
+			.expect("Tests node")
+			.success()
+	);
 
 	// Remove all `target` directories
 	for toml in cargo_tomls {
@@ -174,14 +213,20 @@ fn main() {
 	let cargo_tomls = find_cargo_tomls(build_dir.path().to_owned());
 
 	let commit_id = get_git_commit_id(&options.node_template);
+	let top_level_cargo_toml_path = node_template_path.join("Cargo.toml");
 
 	cargo_tomls.iter().for_each(|t| {
 		let mut cargo_toml = parse_cargo_toml(&t);
 		replace_path_dependencies_with_git(&t, &commit_id, &mut cargo_toml);
 
-		// If this is the top-level `Cargo.toml`, add `profile.release`
-		if &node_template_path.join("Cargo.toml") == t {
-			cargo_toml_add_profile_release(&mut cargo_toml);
+		// Check if this is the top level `Cargo.toml`, as this requires some special treatments.
+		if top_level_cargo_toml_path == *t {
+			// All workspace member `Cargo.toml` file paths.
+			let workspace_members = cargo_tomls.iter()
+				.filter(|p| **p != top_level_cargo_toml_path)
+				.collect();
+
+			update_top_level_cargo_toml(&mut cargo_toml, workspace_members, &node_template_path);
 		}
 
 		write_cargo_toml(&t, cargo_toml);
diff --git a/srml/aura/src/lib.rs b/srml/aura/src/lib.rs
index e02a2e1f0a0ec..4df832912a543 100644
--- a/srml/aura/src/lib.rs
+++ b/srml/aura/src/lib.rs
@@ -258,7 +258,7 @@ impl<T: Trait> Module<T> {
 
 	fn on_timestamp_set(now: T::Moment, slot_duration: T::Moment) {
 		let last = Self::last();
-		<Self as Store>::LastTimestamp::put(now.clone());
+		<Self as Store>::LastTimestamp::put(now);
 
 		if last.is_zero() {
 			return;
@@ -266,7 +266,7 @@ impl<T: Trait> Module<T> {
 
 		assert!(!slot_duration.is_zero(), "Aura slot duration cannot be zero.");
 
-		let last_slot = last / slot_duration.clone();
+		let last_slot = last / slot_duration;
 		let cur_slot = now / slot_duration;
 
 		assert!(last_slot < cur_slot, "Only one block may be authored per slot.");
diff --git a/srml/authority-discovery/Cargo.toml b/srml/authority-discovery/Cargo.toml
index 5d52bdb2461fa..f4c2d4e2b0bd0 100644
--- a/srml/authority-discovery/Cargo.toml
+++ b/srml/authority-discovery/Cargo.toml
@@ -17,6 +17,9 @@ srml-support = { path = "../support", default-features = false }
 sr-io = { package = "sr-io", path = "../../core/sr-io", default-features = false }
 system = { package = "srml-system", path = "../system", default-features = false }
 
+[dev-dependencies]
+sr-staking-primitives = { path = "../../core/sr-staking-primitives", default-features = false }
+
 [features]
 default = ["std"]
 std = [
diff --git a/srml/authority-discovery/src/lib.rs b/srml/authority-discovery/src/lib.rs
index 00912aeffed8b..ffcb6672c8662 100644
--- a/srml/authority-discovery/src/lib.rs
+++ b/srml/authority-discovery/src/lib.rs
@@ -33,18 +33,20 @@ use codec::{Decode, Encode};
 use rstd::prelude::*;
 use srml_support::{decl_module, decl_storage, StorageValue};
 
-pub trait Trait: system::Trait + session::Trait {}
+pub trait Trait: system::Trait + session::Trait + im_online::Trait {}
+
+type AuthorityIdFor<T> = <T as im_online::Trait>::AuthorityId;
 
 decl_storage! {
 	trait Store for Module<T: Trait> as AuthorityDiscovery {
 		/// The current set of keys that may issue a heartbeat.
-		Keys get(keys): Vec<im_online::AuthorityId>;
+		Keys get(keys): Vec<AuthorityIdFor<T>>;
 	}
 	add_extra_genesis {
-		config(keys): Vec<im_online::AuthorityId>;
+		config(keys): Vec<AuthorityIdFor<T>>;
 		build(|
 			  storage: &mut (sr_primitives::StorageOverlay, sr_primitives::ChildrenStorageOverlay),
-			  config: &GenesisConfig
+			  config: &GenesisConfig<T>,
 			  | {
 				  sr_io::with_storage(
 					  storage,
@@ -64,10 +66,10 @@ impl<T: Trait> Module<T> {
 	/// set, otherwise this function returns None. The restriction might be
 	/// softened in the future in case a consumer needs to learn own authority
 	/// identifier.
-	pub fn authority_id() -> Option<im_online::AuthorityId> {
-		let authorities = Keys::get();
+	pub fn authority_id() -> Option<AuthorityIdFor<T>> {
+		let authorities = Keys::<T>::get();
 
-		let local_keys = im_online::AuthorityId::all();
+		let local_keys = <AuthorityIdFor<T>>::all();
 
 		authorities.into_iter().find_map(|authority| {
 			if local_keys.contains(&authority) {
@@ -79,12 +81,12 @@ impl<T: Trait> Module<T> {
 	}
 
 	/// Retrieve authority identifiers of the current authority set.
-	pub fn authorities() -> Vec<im_online::AuthorityId> {
-		Keys::get()
+	pub fn authorities() -> Vec<AuthorityIdFor<T>> {
+		Keys::<T>::get()
 	}
 
 	/// Sign the given payload with the private key corresponding to the given authority id.
-	pub fn sign(payload: Vec<u8>, authority_id: im_online::AuthorityId) -> Option<Vec<u8>> {
+	pub fn sign(payload: Vec<u8>, authority_id: AuthorityIdFor<T>) -> Option<Vec<u8>> {
 		authority_id.sign(&payload).map(|s| s.encode())
 	}
 
@@ -93,27 +95,27 @@ impl<T: Trait> Module<T> {
 	pub fn verify(
 		payload: Vec<u8>,
 		signature: Vec<u8>,
-		authority_id: im_online::AuthorityId,
+		authority_id: AuthorityIdFor<T>,
 	) -> bool {
-		im_online::AuthoritySignature::decode(&mut &signature[..])
+		<AuthorityIdFor<T> as RuntimeAppPublic>::Signature::decode(&mut &signature[..])
 			.map(|s| authority_id.verify(&payload, &s))
 			.unwrap_or(false)
 	}
 
-	fn initialize_keys(keys: &[im_online::AuthorityId]) {
+	fn initialize_keys(keys: &[AuthorityIdFor<T>]) {
 		if !keys.is_empty() {
-			assert!(Keys::get().is_empty(), "Keys are already initialized!");
-			Keys::put_ref(keys);
+			assert!(Keys::<T>::get().is_empty(), "Keys are already initialized!");
+			Keys::<T>::put_ref(keys);
 		}
 	}
 }
 
 impl<T: Trait> session::OneSessionHandler<T::AccountId> for Module<T> {
-	type Key = im_online::AuthorityId;
+	type Key = AuthorityIdFor<T>;
 
 	fn on_genesis_session<'a, I: 'a>(validators: I)
 	where
-		I: Iterator<Item = (&'a T::AccountId, im_online::AuthorityId)>,
+		I: Iterator<Item = (&'a T::AccountId, Self::Key)>,
 	{
 		let keys = validators.map(|x| x.1).collect::<Vec<_>>();
 		Self::initialize_keys(&keys);
@@ -121,10 +123,10 @@ impl<T: Trait> session::OneSessionHandler<T::AccountId> for Module<T> {
 
 	fn on_new_session<'a, I: 'a>(_changed: bool, _validators: I, next_validators: I)
 	where
-		I: Iterator<Item = (&'a T::AccountId, im_online::AuthorityId)>,
+		I: Iterator<Item = (&'a T::AccountId, Self::Key)>,
 	{
 		// Remember who the authorities are for the new session.
-		Keys::put(next_validators.map(|x| x.1).collect::<Vec<_>>());
+		Keys::<T>::put(next_validators.map(|x| x.1).collect::<Vec<_>>());
 	}
 
 	fn on_disabled(_i: usize) {
@@ -139,9 +141,11 @@ mod tests {
 	use primitives::testing::KeyStore;
 	use primitives::{crypto::key_types, sr25519, traits::BareCryptoStore, H256};
 	use sr_io::{with_externalities, TestExternalities};
+	use sr_primitives::generic::UncheckedExtrinsic;
 	use sr_primitives::testing::{Header, UintAuthorityId};
 	use sr_primitives::traits::{ConvertInto, IdentityLookup, OpaqueKeys};
 	use sr_primitives::Perbill;
+	use sr_staking_primitives::CurrentElectedSet;
 	use srml_support::{impl_outer_origin, parameter_types};
 
 	type AuthorityDiscovery = Module<Test>;
@@ -151,12 +155,21 @@ mod tests {
 	pub struct Test;
 	impl Trait for Test {}
 
+	type AuthorityId = im_online::sr25519::AuthorityId;
+
+	pub struct DummyCurrentElectedSet<T>(std::marker::PhantomData<T>);
+	impl<T> CurrentElectedSet<T> for DummyCurrentElectedSet<T> {
+		fn current_elected_set() -> Vec<T> {
+			vec![]
+		}
+	}
+
 	pub struct TestOnSessionEnding;
-	impl session::OnSessionEnding<im_online::AuthorityId> for TestOnSessionEnding {
+	impl session::OnSessionEnding<AuthorityId> for TestOnSessionEnding {
 		fn on_session_ending(
 			_: SessionIndex,
 			_: SessionIndex,
-		) -> Option<Vec<im_online::AuthorityId>> {
+		) -> Option<Vec<AuthorityId>> {
 			None
 		}
 	}
@@ -167,11 +180,25 @@ mod tests {
 		type ShouldEndSession = session::PeriodicSessions<Period, Offset>;
 		type SessionHandler = TestSessionHandler;
 		type Event = ();
-		type ValidatorId = im_online::AuthorityId;
+		type ValidatorId = AuthorityId;
 		type ValidatorIdOf = ConvertInto;
 		type SelectInitialValidators = ();
 	}
 
+	impl session::historical::Trait for Test {
+		type FullIdentification = ();
+		type FullIdentificationOf = ();
+	}
+
+	impl im_online::Trait for Test {
+		type AuthorityId = AuthorityId;
+		type Call = im_online::Call<Test>;
+		type Event = ();
+		type UncheckedExtrinsic = UncheckedExtrinsic<(), im_online::Call<Test>, (), ()>;
+		type ReportUnresponsiveness = ();
+		type CurrentElectedSet = DummyCurrentElectedSet<AuthorityId>;
+	}
+
 	pub type BlockNumber = u64;
 
 	parameter_types! {
@@ -191,7 +218,7 @@ mod tests {
 		type Call = ();
 		type Hash = H256;
 		type Hashing = ::sr_primitives::traits::BlakeTwo256;
-		type AccountId = im_online::AuthorityId;
+		type AccountId = AuthorityId;
 		type Lookup = IdentityLookup<Self::AccountId>;
 		type Header = Header;
 		type WeightMultiplierUpdate = ();
@@ -208,17 +235,17 @@ mod tests {
 	}
 
 	pub struct TestSessionHandler;
-	impl session::SessionHandler<im_online::AuthorityId> for TestSessionHandler {
+	impl session::SessionHandler<AuthorityId> for TestSessionHandler {
 		fn on_new_session<Ks: OpaqueKeys>(
 			_changed: bool,
-			_validators: &[(im_online::AuthorityId, Ks)],
-			_queued_validators: &[(im_online::AuthorityId, Ks)],
+			_validators: &[(AuthorityId, Ks)],
+			_queued_validators: &[(AuthorityId, Ks)],
 		) {
 		}
 
 		fn on_disabled(_validator_index: usize) {}
 
-		fn on_genesis_session<Ks: OpaqueKeys>(_validators: &[(im_online::AuthorityId, Ks)]) {}
+		fn on_genesis_session<Ks: OpaqueKeys>(_validators: &[(AuthorityId, Ks)]) {}
 	}
 
 	#[test]
@@ -236,17 +263,17 @@ mod tests {
 			.sr25519_public_keys(key_types::IM_ONLINE)
 			.pop()
 			.unwrap();
-		let authority_id = im_online::AuthorityId::from(public_key);
+		let authority_id = AuthorityId::from(public_key);
 
 		// Build genesis.
 		let mut t = system::GenesisConfig::default()
 			.build_storage::<Test>()
 			.unwrap();
 
-		GenesisConfig {
+		GenesisConfig::<Test> {
 			keys: vec![authority_id.clone()],
 		}
-		.assimilate_storage::<Test>(&mut t)
+		.assimilate_storage(&mut t)
 		.unwrap();
 
 		// Create externalities.
@@ -279,11 +306,11 @@ mod tests {
 		let keys = vec![(); 5]
 			.iter()
 			.map(|_x| sr25519::Pair::generate_with_phrase(None).0.public())
-			.map(im_online::AuthorityId::from)
+			.map(AuthorityId::from)
 			.collect();
 
-		GenesisConfig { keys: keys }
-			.assimilate_storage::<Test>(&mut t)
+		GenesisConfig::<Test> { keys: keys }
+			.assimilate_storage(&mut t)
 			.unwrap();
 
 		// Create externalities.
@@ -310,17 +337,17 @@ mod tests {
 			.sr25519_public_keys(key_types::IM_ONLINE)
 			.pop()
 			.unwrap();
-		let authority_id = im_online::AuthorityId::from(public_key);
+		let authority_id = AuthorityId::from(public_key);
 
 		// Build genesis.
 		let mut t = system::GenesisConfig::default()
 			.build_storage::<Test>()
 			.unwrap();
 
-		GenesisConfig {
+		GenesisConfig::<Test> {
 			keys: vec![authority_id.clone()],
 		}
-		.assimilate_storage::<Test>(&mut t)
+		.assimilate_storage(&mut t)
 		.unwrap();
 
 		// Create externalities.
diff --git a/srml/authorship/src/lib.rs b/srml/authorship/src/lib.rs
index 424223a2c9a64..c71c26df02a61 100644
--- a/srml/authorship/src/lib.rs
+++ b/srml/authorship/src/lib.rs
@@ -27,7 +27,7 @@ use srml_support::traits::{FindAuthor, VerifySeal, Get};
 use srml_support::dispatch::Result as DispatchResult;
 use codec::{Encode, Decode};
 use system::ensure_none;
-use sr_primitives::traits::{SimpleArithmetic, Header as HeaderT, One, Zero};
+use sr_primitives::traits::{Header as HeaderT, One, Zero};
 use sr_primitives::weights::SimpleDispatchInfo;
 use inherents::{
 	RuntimeString, InherentIdentifier, ProvideInherent,
@@ -236,29 +236,14 @@ decl_storage! {
 	}
 }
 
-fn prune_old_uncles<BlockNumber, Hash, Author>(
-	minimum_height: BlockNumber,
-	uncles: &mut Vec<UncleEntryItem<BlockNumber, Hash, Author>>
-) where BlockNumber: SimpleArithmetic {
-	let prune_entries = uncles.iter().take_while(|item| match item {
-		UncleEntryItem::Uncle(_, _) => true,
-		UncleEntryItem::InclusionHeight(height) => height < &minimum_height,
-	});
-	let prune_index = prune_entries.count();
-
-	let _ = uncles.drain(..prune_index);
-}
-
 decl_module! {
 	pub struct Module<T: Trait> for enum Call where origin: T::Origin {
 		fn on_initialize(now: T::BlockNumber) {
 			let uncle_generations = T::UncleGenerations::get();
-			let mut uncles = <Self as Store>::Uncles::get();
-
 			// prune uncles that are older than the allowed number of generations.
 			if uncle_generations <= now {
 				let minimum_height = now - uncle_generations;
-				prune_old_uncles(minimum_height, &mut uncles)
+				Self::prune_old_uncles(minimum_height)
 			}
 
 			<Self as Store>::DidSetUncles::put(false);
@@ -387,6 +372,18 @@ impl<T: Trait> Module<T> {
 		// check uncle validity.
 		T::FilterUncle::filter_uncle(&uncle, accumulator)
 	}
+
+	fn prune_old_uncles(minimum_height: T::BlockNumber) {
+		let mut uncles = <Self as Store>::Uncles::get();
+		let prune_entries = uncles.iter().take_while(|item| match item {
+			UncleEntryItem::Uncle(_, _) => true,
+			UncleEntryItem::InclusionHeight(height) => height < &minimum_height,
+		});
+		let prune_index = prune_entries.count();
+
+		let _ = uncles.drain(..prune_index);
+		<Self as Store>::Uncles::put(uncles);
+	}
 }
 
 impl<T: Trait> ProvideInherent for Module<T> {
@@ -569,15 +566,21 @@ mod tests {
 	#[test]
 	fn prune_old_uncles_works() {
 		use UncleEntryItem::*;
-		let mut uncles = vec![
-			InclusionHeight(1u32), Uncle((), Some(())), Uncle((), None), Uncle((), None),
-			InclusionHeight(2u32), Uncle((), None),
-			InclusionHeight(3u32), Uncle((), None),
-		];
-
-		prune_old_uncles(3, &mut uncles);
-
-		assert_eq!(uncles, vec![InclusionHeight(3), Uncle((), None)]);
+		with_externalities(&mut new_test_ext(), || {
+			let hash = Default::default();
+			let author = Default::default();
+			let uncles = vec![
+				InclusionHeight(1u64), Uncle(hash, Some(author)), Uncle(hash, None), Uncle(hash, None),
+				InclusionHeight(2u64), Uncle(hash, None),
+				InclusionHeight(3u64), Uncle(hash, None),
+			];
+
+			<Authorship as Store>::Uncles::put(uncles);
+			Authorship::prune_old_uncles(3);
+
+			let uncles = <Authorship as Store>::Uncles::get();
+			assert_eq!(uncles, vec![InclusionHeight(3u64), Uncle(hash, None)]);
+		})
 	}
 
 	#[test]
diff --git a/srml/babe/src/lib.rs b/srml/babe/src/lib.rs
index b58fb26b5a127..0f439d489e8af 100644
--- a/srml/babe/src/lib.rs
+++ b/srml/babe/src/lib.rs
@@ -445,6 +445,8 @@ impl<T: Trait> session::OneSessionHandler<T::AccountId> for Module<T> {
 	fn on_new_session<'a, I: 'a>(_changed: bool, validators: I, queued_validators: I)
 		where I: Iterator<Item=(&'a T::AccountId, AuthorityId)>
 	{
+		Self::do_initialize();
+
 		// Update epoch index
 		let epoch_index = EpochIndex::get()
 			.checked_add(1)
diff --git a/srml/balances/src/lib.rs b/srml/balances/src/lib.rs
index 3f727bfa51bee..0c838970451e1 100644
--- a/srml/balances/src/lib.rs
+++ b/srml/balances/src/lib.rs
@@ -72,8 +72,6 @@
 //! - [`Imbalance`](../srml_support/traits/trait.Imbalance.html): Functions for handling
 //! imbalances between total issuance in the system and account balances. Must be used when a function
 //! creates new funds (e.g. a reward) or destroys some funds (e.g. a system fee).
-//! - [`MakePayment`](../srml_support/traits/trait.MakePayment.html): Simple trait designed
-//! for hooking into a transaction payment.
 //! - [`IsDeadAccount`](../srml_system/trait.IsDeadAccount.html): Determiner to say whether a
 //! given account is unused.
 //!
@@ -88,6 +86,17 @@
 //!
 //! - `vesting_balance` - Get the amount that is currently being vested and cannot be transferred out of this account.
 //!
+//! ### Signed Extensions
+//!
+//! The balances module defines the following extensions:
+//!
+//!   - [`TakeFees`]: Consumes fees proportional to the length and weight of the transaction.
+//!     Additionally, it can contain a single encoded payload as a `tip`. The inclusion priority
+//!     is increased proportional to the tip.
+//!
+//! Lookup the runtime aggregator file (e.g. `node/runtime`) to see the full list of signed
+//! extensions included in a chain.
+//!
 //! ## Usage
 //!
 //! The following examples show how to use the Balances module in your custom module.
@@ -172,12 +181,6 @@ mod tests;
 
 pub use self::imbalances::{PositiveImbalance, NegativeImbalance};
 
-pub const DEFAULT_EXISTENTIAL_DEPOSIT: u32 = 0;
-pub const DEFAULT_TRANSFER_FEE: u32 = 0;
-pub const DEFAULT_CREATION_FEE: u32 = 0;
-pub const DEFAULT_TRANSACTION_BASE_FEE: u32 = 0;
-pub const DEFAULT_TRANSACTION_BYTE_FEE: u32 = 0;
-
 pub trait Subtrait<I: Instance = DefaultInstance>: system::Trait {
 	/// The balance of an account.
 	type Balance: Parameter + Member + SimpleArithmetic + Codec + Default + Copy +
@@ -459,7 +462,7 @@ decl_module! {
 		/// - Independent of the arguments.
 		/// - Contains a limited number of reads and writes.
 		/// # </weight>
-		#[weight = SimpleDispatchInfo::FixedOperational(500_000)]
+		#[weight = SimpleDispatchInfo::FixedOperational(50_000)]
 		fn set_balance(
 			origin,
 			who: <T::Lookup as StaticLookup>::Source,
@@ -485,6 +488,21 @@ decl_module! {
 			}
 			Self::set_reserved_balance(&who, new_reserved);
 		}
+
+		/// Exactly as `transfer`, except the origin must be root and the source account may be
+		/// specified.
+		#[weight = SimpleDispatchInfo::FixedNormal(1_000_000)]
+		pub fn force_transfer(
+			origin,
+			source: <T::Lookup as StaticLookup>::Source,
+			dest: <T::Lookup as StaticLookup>::Source,
+			#[compact] value: T::Balance
+		) {
+			ensure_root(origin)?;
+			let source = T::Lookup::lookup(source)?;
+			let dest = T::Lookup::lookup(dest)?;
+			<Self as Currency<_>>::transfer(&source, &dest, value)?;
+		}
 	}
 }
 
diff --git a/srml/balances/src/tests.rs b/srml/balances/src/tests.rs
index 338513d40d267..1af3ce6ba013b 100644
--- a/srml/balances/src/tests.rs
+++ b/srml/balances/src/tests.rs
@@ -26,6 +26,7 @@ use srml_support::{
 	traits::{LockableCurrency, LockIdentifier, WithdrawReason, WithdrawReasons,
 	Currency, ReservableCurrency}
 };
+use system::RawOrigin;
 
 const ID_1: LockIdentifier = *b"1       ";
 const ID_2: LockIdentifier = *b"2       ";
@@ -352,6 +353,20 @@ fn balance_transfer_works() {
 	});
 }
 
+#[test]
+fn force_transfer_works() {
+	with_externalities(&mut ExtBuilder::default().build(), || {
+		let _ = Balances::deposit_creating(&1, 111);
+		assert_noop!(
+			Balances::force_transfer(Some(2).into(), 1, 2, 69),
+			"bad origin: expected to be a root origin"
+		);
+		assert_ok!(Balances::force_transfer(RawOrigin::Root.into(), 1, 2, 69));
+		assert_eq!(Balances::total_balance(&1), 42);
+		assert_eq!(Balances::total_balance(&2), 69);
+	});
+}
+
 #[test]
 fn reserving_balance_should_work() {
 	with_externalities(&mut ExtBuilder::default().build(), || {
diff --git a/srml/contracts/src/lib.rs b/srml/contracts/src/lib.rs
index 9f9fae52922bf..f8485f848ad15 100644
--- a/srml/contracts/src/lib.rs
+++ b/srml/contracts/src/lib.rs
@@ -425,7 +425,8 @@ where
 }
 
 /// The default dispatch fee computor computes the fee in the same way that
-/// the implementation of `MakePayment` for the Balances module does.
+/// the implementation of `TakeFees` for the Balances module does. Note that this only takes a fixed
+/// fee based on size. Unlike the balances module, weight-fee is applied.
 pub struct DefaultDispatchFeeComputor<T: Trait>(PhantomData<T>);
 impl<T: Trait> ComputeDispatchFee<<T as Trait>::Call, BalanceOf<T>> for DefaultDispatchFeeComputor<T> {
 	fn compute_dispatch_fee(call: &<T as Trait>::Call) -> BalanceOf<T> {
diff --git a/srml/democracy/src/lib.rs b/srml/democracy/src/lib.rs
index cfac7fdfbcfe1..4853d192c4bee 100644
--- a/srml/democracy/src/lib.rs
+++ b/srml/democracy/src/lib.rs
@@ -24,11 +24,11 @@ use sr_primitives::traits::{Zero, Bounded, CheckedMul, CheckedDiv, EnsureOrigin,
 use sr_primitives::weights::SimpleDispatchInfo;
 use codec::{Encode, Decode, Input, Output, Error};
 use srml_support::{
-	decl_module, decl_storage, decl_event, ensure,
-	StorageValue, StorageMap, Parameter, Dispatchable, EnumerableStorageMap,
+	decl_module, decl_storage, decl_event, ensure, AppendableStorageMap, StorageValue, StorageMap,
+	Parameter, Dispatchable, EnumerableStorageMap,
 	traits::{
-		Currency, ReservableCurrency, LockableCurrency, WithdrawReason, LockIdentifier,
-		OnFreeBalanceZero, Get
+		Currency, ReservableCurrency, LockableCurrency, WithdrawReason, LockIdentifier, Get,
+		OnFreeBalanceZero
 	}
 };
 use srml_support::dispatch::Result;
@@ -174,13 +174,6 @@ impl Decode for Vote {
 
 type BalanceOf<T> = <<T as Trait>::Currency as Currency<<T as system::Trait>::AccountId>>::Balance;
 
-pub const DEFAULT_ENACTMENT_PERIOD: u32 = 0;
-pub const DEFAULT_LAUNCH_PERIOD: u32 = 0;
-pub const DEFAULT_VOTING_PERIOD: u32 = 0;
-pub const DEFAULT_MINIMUM_DEPOSIT: u32 = 0;
-pub const DEFAULT_EMERGENCY_VOTING_PERIOD: u32 = 0;
-pub const DEFAULT_COOLOFF_PERIOD: u32 = 0;
-
 pub trait Trait: system::Trait + Sized {
 	type Proposal: Parameter + Dispatchable<Origin=Self::Origin>;
 	type Event: From<Event<Self>> + Into<<Self as system::Trait>::Event>;
@@ -384,9 +377,8 @@ decl_module! {
 			PublicPropCount::put(index + 1);
 			<DepositOf<T>>::insert(index, (value, vec![who.clone()]));
 
-			let mut props = Self::public_props();
-			props.push((index, (*proposal).clone(), who));
-			<PublicProps<T>>::put(props);
+			let new_prop = (index, (*proposal).clone(), who);
+			<PublicProps<T>>::append_or_put([new_prop].into_iter());
 
 			Self::deposit_event(RawEvent::Proposed(index, value));
 		}
@@ -795,7 +787,7 @@ impl<T: Trait> Module<T> {
 	fn do_vote(who: T::AccountId, ref_index: ReferendumIndex, vote: Vote) -> Result {
 		ensure!(Self::is_active_referendum(ref_index), "vote given for invalid referendum.");
 		if !<VoteOf<T>>::exists(&(ref_index, who.clone())) {
-			<VotersFor<T>>::mutate(ref_index, |voters| voters.push(who.clone()));
+			<VotersFor<T>>::append_or_insert(ref_index, [who.clone()].into_iter());
 		}
 		<VoteOf<T>>::insert(&(ref_index, who), vote);
 		Ok(())
@@ -933,9 +925,9 @@ impl<T: Trait> Module<T> {
 			if info.delay.is_zero() {
 				Self::enact_proposal(info.proposal, index);
 			} else {
-				<DispatchQueue<T>>::mutate(
+				<DispatchQueue<T>>::append_or_insert(
 					now + info.delay,
-					|q| q.push(Some((info.proposal, index)))
+					[Some((info.proposal, index))].into_iter()
 				);
 			}
 		} else {
@@ -953,12 +945,12 @@ impl<T: Trait> Module<T> {
 		if (now % T::LaunchPeriod::get()).is_zero() {
 			// Errors come from the queue being empty. we don't really care about that, and even if
 			// we did, there is nothing we can do here.
-			let _ = Self::launch_next(now.clone());
+			let _ = Self::launch_next(now);
 		}
 
 		// tally up votes for any expiring referenda.
 		for (index, info) in Self::maturing_referenda_at(now).into_iter() {
-			Self::bake_referendum(now.clone(), index, info)?;
+			Self::bake_referendum(now, index, info)?;
 		}
 
 		for (proposal, index) in <DispatchQueue<T>>::take(now).into_iter().filter_map(|x| x) {
diff --git a/srml/elections/src/lib.rs b/srml/elections/src/lib.rs
index a82b3fab7ef1d..9c49b9055b9bc 100644
--- a/srml/elections/src/lib.rs
+++ b/srml/elections/src/lib.rs
@@ -28,7 +28,7 @@ use sr_primitives::traits::{Zero, One, StaticLookup, Bounded, Saturating};
 use sr_primitives::weights::SimpleDispatchInfo;
 use runtime_io::print;
 use srml_support::{
-	StorageValue, StorageMap,
+	StorageValue, StorageMap, AppendableStorageMap, DecodeLengthStorageMap,
 	dispatch::Result, decl_storage, decl_event, ensure, decl_module,
 	traits::{
 		Currency, ExistenceRequirement, Get, LockableCurrency, LockIdentifier,
@@ -138,18 +138,8 @@ pub type VoteIndex = u32;
 
 // all three must be in sync.
 type ApprovalFlag = u32;
-pub const APPROVAL_FLAG_MASK: ApprovalFlag = 0x8000_0000;
 pub const APPROVAL_FLAG_LEN: usize = 32;
 
-pub const DEFAULT_CANDIDACY_BOND: u32 = 9;
-pub const DEFAULT_VOTING_BOND: u32 = 0;
-pub const DEFAULT_VOTING_FEE: u32 = 0;
-pub const DEFAULT_PRESENT_SLASH_PER_VOTER: u32 = 1;
-pub const DEFAULT_CARRY_COUNT: u32 = 2;
-pub const DEFAULT_INACTIVE_GRACE_PERIOD: u32 = 1;
-pub const DEFAULT_VOTING_PERIOD: u32 = 1000;
-pub const DEFAULT_DECAY_RATIO: u32 = 24;
-
 pub trait Trait: system::Trait {
 	type Event: From<Event<Self>> + Into<<Self as system::Trait>::Event>;
 
@@ -724,15 +714,15 @@ impl<T: Trait> Module<T> {
 	///
 	/// The voter index must be provided as explained in [`voter_at`] function.
 	fn do_set_approvals(who: T::AccountId, votes: Vec<bool>, index: VoteIndex, hint: SetIndex) -> Result {
-		let candidates = Self::candidates();
+		let candidates_len = <Self as Store>::Candidates::decode_len().unwrap_or(0_usize);
 
 		ensure!(!Self::presentation_active(), "no approval changes during presentation period");
 		ensure!(index == Self::vote_index(), "incorrect vote index");
-		ensure!(!candidates.is_empty(), "amount of candidates to receive approval votes should be non-zero");
+		ensure!(!candidates_len.is_zero(), "amount of candidates to receive approval votes should be non-zero");
 		// Prevent a vote from voters that provide a list of votes that exceeds the candidates length
 		// since otherwise an attacker may be able to submit a very long list of `votes` that far exceeds
 		// the amount of candidates and waste more computation than a reasonable voting bond would cover.
-		ensure!(candidates.len() >= votes.len(), "amount of candidate votes cannot exceed amount of candidates");
+		ensure!(candidates_len >= votes.len(), "amount of candidate votes cannot exceed amount of candidates");
 
 		// Amount to be locked up.
 		let mut locked_balance = T::Currency::total_balance(&who);
@@ -765,10 +755,10 @@ impl<T: Trait> Module<T> {
 				CellStatus::Head | CellStatus::Occupied => {
 					// Either occupied or out-of-range.
 					let next = Self::next_nonfull_voter_set();
-					let mut set = Self::voters(next);
+					let set_len = <Voters<T>>::decode_len(next).unwrap_or(0_usize);
 					// Caused a new set to be created. Pay for it.
 					// This is the last potential error. Writes will begin afterwards.
-					if set.is_empty() {
+					if set_len == 0 {
 						let imbalance = T::Currency::withdraw(
 							&who,
 							T::VotingFee::get(),
@@ -779,8 +769,10 @@ impl<T: Trait> Module<T> {
 						// NOTE: this is safe since the `withdraw()` will check this.
 						locked_balance -= T::VotingFee::get();
 					}
-					Self::checked_push_voter(&mut set, who.clone(), next);
-					<Voters<T>>::insert(next, set);
+					if set_len + 1 == VOTER_SET_SIZE {
+						NextVoterSet::put(next + 1);
+					}
+					<Voters<T>>::append_or_insert(next, [Some(who.clone())].into_iter())
 				}
 			}
 
@@ -918,18 +910,6 @@ impl<T: Trait> Module<T> {
 		Ok(())
 	}
 
-	fn checked_push_voter(set: &mut Vec<Option<T::AccountId>>, who: T::AccountId, index: u32) {
-		let len = set.len();
-
-		// Defensive only: this should never happen. Don't push since it will break more things.
-		if len == VOTER_SET_SIZE { return; }
-
-		set.push(Some(who));
-		if len + 1 == VOTER_SET_SIZE {
-			NextVoterSet::put(index + 1);
-		}
-	}
-
 	/// Get the set and vector index of a global voter index.
 	///
 	/// Note that this function does not take holes into account.
diff --git a/srml/example/Cargo.toml b/srml/example/Cargo.toml
index 87069a487a19a..73e280605a1c7 100644
--- a/srml/example/Cargo.toml
+++ b/srml/example/Cargo.toml
@@ -11,9 +11,10 @@ srml-support = { path = "../support", default-features = false }
 system = { package = "srml-system", path = "../system", default-features = false }
 balances = { package = "srml-balances", path = "../balances", default-features = false }
 sr-primitives = { path = "../../core/sr-primitives", default-features = false }
+rstd = { package = "sr-std", path = "../../core/sr-std", default-features = false }
+rio = { package = "sr-io", path = "../../core/sr-io", default-features = false }
 
 [dev-dependencies]
-sr-io = { path = "../../core/sr-io" }
 primitives = { package = "substrate-primitives",  path = "../../core/primitives" }
 
 [features]
@@ -25,4 +26,6 @@ std = [
 	"srml-support/std",
 	"system/std",
 	"balances/std",
+	"rio/std",
+	"rstd/std"
 ]
diff --git a/srml/example/src/lib.rs b/srml/example/src/lib.rs
index 1c0191b69d8bd..3de961f5cdcf5 100644
--- a/srml/example/src/lib.rs
+++ b/srml/example/src/lib.rs
@@ -253,9 +253,15 @@
 // Ensure we're `no_std` when compiling for Wasm.
 #![cfg_attr(not(feature = "std"), no_std)]
 
+use rstd::marker::PhantomData;
 use srml_support::{StorageValue, dispatch::Result, decl_module, decl_storage, decl_event};
 use system::{ensure_signed, ensure_root};
-use sr_primitives::weights::SimpleDispatchInfo;
+use codec::{Encode, Decode};
+use sr_primitives::{
+	traits::{SignedExtension, DispatchError, Bounded},
+	transaction_validity::ValidTransaction,
+	weights::{SimpleDispatchInfo, DispatchInfo},
+};
 
 /// Our module's configuration trait. All our types and consts go in here. If the
 /// module is dependent on specific other modules, then their configuration traits
@@ -500,15 +506,96 @@ impl<T: Trait> Module<T> {
 	}
 }
 
+// Similar to other SRML modules, your module can also define a signed extension and perform some
+// checks and [pre/post]processing [before/after] the transaction. A signed extension can be any
+// decodable type that implements `SignedExtension`. See the trait definition for the full list of
+// bounds. As a convention, you can follow this approach to create an extension for your module:
+//   - If the extension does not carry any data, then use a tuple struct with just a `marker`
+//     (needed for the compiler to accept `T: Trait`) will suffice.
+//   - Otherwise, create a tuple struct which contains the external data. Of course, for the entire
+//     struct to be decodable, each individual item also needs to be decodable.
+//
+// Note that a signed extension can also indicate that a particular data must be present in the
+// _signing payload_ of a transaction by providing an implementation for the `additional_signed`
+// method. This example will not cover this type of extension. See `CheckRuntime` in system module
+// for an example.
+//
+// Using the extension, you can add some hooks to the lifecycle of each transaction. Note that by
+// default, an extension is applied to all `Call` functions (i.e. all transactions). the `Call` enum
+// variant is given to each function of `SignedExtension`. Hence, you can filter based on module or
+// a particular call if needed.
+//
+// Some extra information, such as encoded length, some static dispatch info like weight and the
+// sender of the transaction (if signed) are also provided.
+//
+// The full list of hooks that can be added to a signed extension can be found
+// [here](https://crates.parity.io/sr_primitives/traits/trait.SignedExtension.html).
+//
+// The signed extensions are aggregated in the runtime file of a substrate chain. All extensions
+// should be aggregated in a tuple and passed to the `CheckedExtrinsic` and `UncheckedExtrinsic`
+// types defined in the runtime. Lookup `pub type SignedExtra = (...)` in `node/runtime` and
+// `node-template` for an example of this.
+
+/// A simple signed extension that checks for the `set_dummy` call. In that case, it increases the
+/// priority and prints some log.
+///
+/// Additionally, it drops any transaction with an encoded length higher than 200 bytes. No
+/// particular reason why, just to demonstrate the power of signed extensions.
+#[derive(Encode, Decode, Clone, Eq, PartialEq)]
+pub struct WatchDummy<T: Trait + Send + Sync>(PhantomData<T>);
+
+#[cfg(feature = "std")]
+impl<T: Trait + Send + Sync> rstd::fmt::Debug for WatchDummy<T> {
+	fn fmt(&self, f: &mut rstd::fmt::Formatter) -> rstd::fmt::Result {
+		write!(f, "WatchDummy<T>")
+	}
+}
+
+impl<T: Trait + Send + Sync> SignedExtension for WatchDummy<T> {
+	type AccountId = T::AccountId;
+	// Note that this could also be assigned to the top-level call enum. It is passed into the
+	// balances module directly and since `Trait: balances::Trait`, you could also use `T::Call`.
+	// In that case, you would have had access to all call variants and could match on variants from
+	// other modules.
+	type Call = Call<T>;
+	type AdditionalSigned = ();
+	type Pre = ();
+
+	fn additional_signed(&self) -> rstd::result::Result<(), &'static str> { Ok(()) }
+
+	fn validate(
+		&self,
+		_who: &Self::AccountId,
+		call: &Self::Call,
+		_info: DispatchInfo,
+		len: usize,
+	) -> rstd::result::Result<ValidTransaction, DispatchError> {
+		// if the transaction is too big, just drop it.
+		if len > 200 { return Err(DispatchError::Exhausted) }
+
+		// check for `set_dummy`
+		match call {
+			Call::set_dummy(..) => {
+				rio::print("set_dummy was received.");
+
+				let mut valid_tx = ValidTransaction::default();
+				valid_tx.priority = Bounded::max_value();
+				Ok(valid_tx)
+			}
+			_ => Ok(Default::default())
+		}
+	}
+}
+
 #[cfg(test)]
 mod tests {
 	use super::*;
 
 	use srml_support::{assert_ok, impl_outer_origin, parameter_types};
-	use sr_io::with_externalities;
+	use rio::with_externalities;
 	use primitives::{H256, Blake2Hasher};
 	// The testing primitives are very useful for avoiding having to work with signatures
-	// or public keys. `u64` is used as the `AccountId` and no `Signature`s are requried.
+	// or public keys. `u64` is used as the `AccountId` and no `Signature`s are required.
 	use sr_primitives::{
 		Perbill, traits::{BlakeTwo256, OnInitialize, OnFinalize, IdentityLookup}, testing::Header
 	};
@@ -575,7 +662,7 @@ mod tests {
 
 	// This function basically just builds a genesis storage key/value store according to
 	// our desired mockup.
-	fn new_test_ext() -> sr_io::TestExternalities<Blake2Hasher> {
+	fn new_test_ext() -> rio::TestExternalities<Blake2Hasher> {
 		let mut t = system::GenesisConfig::default().build_storage::<Test>().unwrap();
 		// We use default for brevity, but you can configure as desired if needed.
 		balances::GenesisConfig::<Test>::default().assimilate_storage(&mut t).unwrap();
@@ -617,4 +704,21 @@ mod tests {
 			assert_eq!(Example::foo(), 25);
 		});
 	}
+
+	#[test]
+	fn signed_ext_watch_dummy_works() {
+		with_externalities(&mut new_test_ext(), || {
+			let call = <Call<Test>>::set_dummy(10);
+			let info = DispatchInfo::default();
+
+			assert_eq!(
+				WatchDummy::<Test>(PhantomData).validate(&1, &call, info, 150).unwrap().priority,
+				Bounded::max_value()
+			);
+			assert_eq!(
+				WatchDummy::<Test>(PhantomData).validate(&1, &call, info, 250),
+				Err(DispatchError::Exhausted)
+			);
+		})
+	}
 }
diff --git a/srml/grandpa/src/lib.rs b/srml/grandpa/src/lib.rs
index d64939ae0a766..5fc354eab96a7 100644
--- a/srml/grandpa/src/lib.rs
+++ b/srml/grandpa/src/lib.rs
@@ -33,7 +33,8 @@ pub use substrate_finality_grandpa_primitives as fg_primitives;
 use rstd::prelude::*;
 use codec::{self as codec, Encode, Decode, Error};
 use srml_support::{
-	decl_event, decl_storage, decl_module, dispatch::Result, storage::StorageValue
+	decl_event, decl_storage, decl_module, dispatch::Result,
+	storage::StorageValue, storage::StorageMap,
 };
 use sr_primitives::{
 	generic::{DigestItem, OpaqueDigestItemId}, traits::Zero,
@@ -43,7 +44,7 @@ use sr_staking_primitives::{
 	SessionIndex,
 	offence::{Offence, Kind},
 };
-use fg_primitives::{ScheduledChange, ConsensusLog, GRANDPA_ENGINE_ID};
+use fg_primitives::{GRANDPA_ENGINE_ID, ScheduledChange, ConsensusLog, SetId, RoundNumber};
 pub use fg_primitives::{AuthorityId, AuthorityWeight};
 use system::{ensure_signed, DigestOf};
 
@@ -65,7 +66,7 @@ pub struct OldStoredPendingChange<N> {
 	/// The delay in blocks until it will be applied.
 	pub delay: N,
 	/// The next authority set.
-	pub next_authorities: Vec<(AuthorityId, u64)>,
+	pub next_authorities: Vec<(AuthorityId, AuthorityWeight)>,
 }
 
 /// A stored pending change.
@@ -76,7 +77,7 @@ pub struct StoredPendingChange<N> {
 	/// The delay in blocks until it will be applied.
 	pub delay: N,
 	/// The next authority set.
-	pub next_authorities: Vec<(AuthorityId, u64)>,
+	pub next_authorities: Vec<(AuthorityId, AuthorityWeight)>,
 	/// If defined it means the change was forced and the given block number
 	/// indicates the median last finalized block when the change was signaled.
 	pub forced: Option<N>,
@@ -127,7 +128,7 @@ pub enum StoredState<N> {
 decl_event!(
 	pub enum Event {
 		/// New authority set has been applied.
-		NewAuthorities(Vec<(AuthorityId, u64)>),
+		NewAuthorities(Vec<(AuthorityId, AuthorityWeight)>),
 		/// Current authority set has been paused.
 		Paused,
 		/// Current authority set has been resumed.
@@ -151,6 +152,13 @@ decl_storage! {
 
 		/// `true` if we are currently stalled.
 		Stalled get(stalled): Option<(T::BlockNumber, T::BlockNumber)>;
+
+		/// The number of changes (both in terms of keys and underlying economic responsibilities)
+		/// in the "set" of Grandpa validators from genesis.
+		CurrentSetId get(current_set_id) build(|_| fg_primitives::SetId::default()): SetId;
+
+		/// A mapping from grandpa set ID to the index of the *most recent* session for which its members were responsible.
+		SetIdSession get(session_for_set): map SetId => Option<SessionIndex>;
 	}
 	add_extra_genesis {
 		config(authorities): Vec<(AuthorityId, AuthorityWeight)>;
@@ -243,7 +251,7 @@ decl_module! {
 
 impl<T: Trait> Module<T> {
 	/// Get the current set of authorities, along with their respective weights.
-	pub fn grandpa_authorities() -> Vec<(AuthorityId, u64)> {
+	pub fn grandpa_authorities() -> Vec<(AuthorityId, AuthorityWeight)> {
 		Authorities::get()
 	}
 
@@ -292,7 +300,7 @@ impl<T: Trait> Module<T> {
 	/// No change should be signaled while any change is pending. Returns
 	/// an error if a change is already pending.
 	pub fn schedule_change(
-		next_authorities: Vec<(AuthorityId, u64)>,
+		next_authorities: Vec<(AuthorityId, AuthorityWeight)>,
 		in_blocks: T::BlockNumber,
 		forced: Option<T::BlockNumber>,
 	) -> Result {
@@ -337,29 +345,34 @@ impl<T: Trait> Module<T> {
 }
 
 impl<T: Trait> Module<T> {
+	/// Attempt to extract a GRANDPA log from a generic digest.
 	pub fn grandpa_log(digest: &DigestOf<T>) -> Option<ConsensusLog<T::BlockNumber>> {
 		let id = OpaqueDigestItemId::Consensus(&GRANDPA_ENGINE_ID);
 		digest.convert_first(|l| l.try_to::<ConsensusLog<T::BlockNumber>>(id))
 	}
 
+	/// Attempt to extract a pending set-change signal from a digest.
 	pub fn pending_change(digest: &DigestOf<T>)
 		-> Option<ScheduledChange<T::BlockNumber>>
 	{
 		Self::grandpa_log(digest).and_then(|signal| signal.try_into_change())
 	}
 
+	/// Attempt to extract a forced set-change signal from a digest.
 	pub fn forced_change(digest: &DigestOf<T>)
 		-> Option<(T::BlockNumber, ScheduledChange<T::BlockNumber>)>
 	{
 		Self::grandpa_log(digest).and_then(|signal| signal.try_into_forced_change())
 	}
 
+	/// Attempt to extract a pause signal from a digest.
 	pub fn pending_pause(digest: &DigestOf<T>)
 		-> Option<T::BlockNumber>
 	{
 		Self::grandpa_log(digest).and_then(|signal| signal.try_into_pause())
 	}
 
+	/// Attempt to extract a resume signal from a digest.
 	pub fn pending_resume(digest: &DigestOf<T>)
 		-> Option<T::BlockNumber>
 	{
@@ -367,7 +380,9 @@ impl<T: Trait> Module<T> {
 	}
 }
 
-impl<T: Trait> session::OneSessionHandler<T::AccountId> for Module<T> {
+impl<T: Trait> session::OneSessionHandler<T::AccountId> for Module<T>
+	where T: session::Trait
+{
 	type Key = AuthorityId;
 
 	fn on_genesis_session<'a, I: 'a>(validators: I)
@@ -380,18 +395,27 @@ impl<T: Trait> session::OneSessionHandler<T::AccountId> for Module<T> {
 	fn on_new_session<'a, I: 'a>(changed: bool, validators: I, _queued_validators: I)
 		where I: Iterator<Item=(&'a T::AccountId, AuthorityId)>
 	{
-		// instant changes
-		if changed {
+		// Always issue a change if `session` says that the validators have changed.
+		// Even if their session keys are the same as before, the underyling economic
+		// identities have changed.
+		let current_set_id = if changed {
 			let next_authorities = validators.map(|(_, k)| (k, 1)).collect::<Vec<_>>();
-			let last_authorities = <Module<T>>::grandpa_authorities();
-			if next_authorities != last_authorities {
-				if let Some((further_wait, median)) = <Stalled<T>>::take() {
-					let _ = Self::schedule_change(next_authorities, further_wait, Some(median));
-				} else {
-					let _ = Self::schedule_change(next_authorities, Zero::zero(), None);
-				}
+			if let Some((further_wait, median)) = <Stalled<T>>::take() {
+				let _ = Self::schedule_change(next_authorities, further_wait, Some(median));
+			} else {
+				let _ = Self::schedule_change(next_authorities, Zero::zero(), None);
 			}
-		}
+			CurrentSetId::mutate(|s| { *s += 1; *s })
+		} else {
+			// nothing's changed, neither economic conditions nor session keys. update the pointer
+			// of the current set.
+			Self::current_set_id()
+		};
+
+		// if we didn't issue a change, we update the mapping to note that the current
+		// set corresponds to the latest equivalent session (i.e. now).
+		let session_index = <session::Module<T>>::current_index();
+		SetIdSession::insert(current_set_id, &session_index);
 	}
 
 	fn on_disabled(i: usize) {
@@ -412,8 +436,8 @@ impl<T: Trait> finality_tracker::OnFinalizationStalled<T::BlockNumber> for Modul
 #[derive(Copy, Clone, PartialOrd, Ord, Eq, PartialEq, Encode, Decode)]
 struct GrandpaTimeSlot {
 	// The order of these matters for `derive(Ord)`.
-	set_id: u64,
-	round: u64,
+	set_id: SetId,
+	round: RoundNumber,
 }
 
 // TODO [slashing]: Integrate this.
diff --git a/srml/im-online/src/lib.rs b/srml/im-online/src/lib.rs
index 0a5d03770bb4d..06a350655bc9d 100644
--- a/srml/im-online/src/lib.rs
+++ b/srml/im-online/src/lib.rs
@@ -67,7 +67,7 @@
 // Ensure we're `no_std` when compiling for Wasm.
 #![cfg_attr(not(feature = "std"), no_std)]
 
-use app_crypto::RuntimeAppPublic;
+use app_crypto::{AppPublic, RuntimeAppPublic};
 use codec::{Encode, Decode};
 use primitives::offchain::{OpaqueNetworkState, StorageKind};
 use rstd::prelude::*;
@@ -75,7 +75,7 @@ use session::historical::IdentificationTuple;
 use sr_io::Printable;
 use sr_primitives::{
 	Perbill, ApplyError,
-	traits::{Extrinsic as ExtrinsicT, Convert},
+	traits::{Convert, Extrinsic as ExtrinsicT, Member},
 	transaction_validity::{TransactionValidity, TransactionLongevity, ValidTransaction},
 };
 use sr_staking_primitives::{
@@ -83,28 +83,44 @@ use sr_staking_primitives::{
 	offence::{ReportOffence, Offence, Kind},
 };
 use srml_support::{
-	StorageValue, decl_module, decl_event, decl_storage, StorageDoubleMap, print, ensure
+	decl_module, decl_event, decl_storage, print, ensure,
+	Parameter, StorageValue, StorageDoubleMap,
 };
 use system::ensure_none;
 
-mod app {
-	pub use app_crypto::ed25519 as crypto;
-	use app_crypto::{app_crypto, key_types::IM_ONLINE, ed25519};
+pub mod sr25519 {
+	mod app_sr25519 {
+		use app_crypto::{app_crypto, key_types::IM_ONLINE, sr25519};
+		app_crypto!(sr25519, IM_ONLINE);
+	}
+
+	/// An i'm online keypair using sr25519 as its crypto.
+	#[cfg(feature = "std")]
+	pub type AuthorityPair = app_sr25519::Pair;
 
-	app_crypto!(ed25519, IM_ONLINE);
+	/// An i'm online signature using sr25519 as its crypto.
+	pub type AuthoritySignature = app_sr25519::Signature;
+
+	/// An i'm online identifier using sr25519 as its crypto.
+	pub type AuthorityId = app_sr25519::Public;
 }
 
-/// A Babe authority keypair. Necessarily equivalent to the schnorrkel public key used in
-/// the main Babe module. If that ever changes, then this must, too.
-#[cfg(feature = "std")]
-pub type AuthorityPair = app::Pair;
+pub mod ed25519 {
+	mod app_ed25519 {
+		use app_crypto::{app_crypto, key_types::IM_ONLINE, ed25519};
+		app_crypto!(ed25519, IM_ONLINE);
+	}
+
+	/// An i'm online keypair using ed25519 as its crypto.
+	#[cfg(feature = "std")]
+	pub type AuthorityPair = app_ed25519::Pair;
 
-/// A Babe authority signature.
-pub type AuthoritySignature = app::Signature;
+	/// An i'm online signature using ed25519 as its crypto.
+	pub type AuthoritySignature = app_ed25519::Signature;
 
-/// A Babe authority identifier. Necessarily equivalent to the schnorrkel public key used in
-/// the main Babe module. If that ever changes, then this must, too.
-pub type AuthorityId = app::Public;
+	/// An i'm online identifier using ed25519 as its crypto.
+	pub type AuthorityId = app_ed25519::Public;
+}
 
 // The local storage database key under which the worker progress status
 // is tracked.
@@ -158,10 +174,13 @@ pub struct Heartbeat<BlockNumber>
 }
 
 pub trait Trait: system::Trait + session::historical::Trait {
+	/// The identifier type for an authority.
+	type AuthorityId: Member + Parameter + AppPublic + RuntimeAppPublic + Default;
+
 	/// The overarching event type.
-	type Event: From<Event> + Into<<Self as system::Trait>::Event>;
+	type Event: From<Event<Self>> + Into<<Self as system::Trait>::Event>;
 
-	/// The function call.
+	/// A dispatchable call type.
 	type Call: From<Call<Self>>;
 
 	/// A extrinsic right from the external world. This is unchecked and so
@@ -181,7 +200,9 @@ pub trait Trait: system::Trait + session::historical::Trait {
 }
 
 decl_event!(
-	pub enum Event {
+	pub enum Event<T> where
+		<T as Trait>::AuthorityId,
+	{
 		/// A new heartbeat was received from `AuthorityId`
 		HeartbeatReceived(AuthorityId),
 	}
@@ -193,7 +214,7 @@ decl_storage! {
 		GossipAt get(gossip_at): T::BlockNumber;
 
 		/// The current set of keys that may issue a heartbeat.
-		Keys get(keys): Vec<AuthorityId>;
+		Keys get(keys): Vec<T::AuthorityId>;
 
 		/// For each session index we keep a mapping of `AuthorityId`
 		/// to `offchain::OpaqueNetworkState`.
@@ -201,10 +222,10 @@ decl_storage! {
 			blake2_256(AuthIndex) => Vec<u8>;
 	}
 	add_extra_genesis {
-		config(keys): Vec<AuthorityId>;
+		config(keys): Vec<T::AuthorityId>;
 		build(|
 			storage: &mut (sr_primitives::StorageOverlay, sr_primitives::ChildrenStorageOverlay),
-			config: &GenesisConfig
+			config: &GenesisConfig<T>
 		| {
 			sr_io::with_storage(
 				storage,
@@ -217,12 +238,12 @@ decl_storage! {
 
 decl_module! {
 	pub struct Module<T: Trait> for enum Call where origin: T::Origin {
-		fn deposit_event() = default;
+		fn deposit_event<T>() = default;
 
 		fn heartbeat(
 			origin,
 			heartbeat: Heartbeat<T::BlockNumber>,
-			signature: AuthoritySignature
+			signature: <T::AuthorityId as RuntimeAppPublic>::Signature
 		) {
 			ensure_none(origin)?;
 
@@ -232,7 +253,7 @@ decl_module! {
 				&current_session,
 				&heartbeat.authority_index
 			);
-			let keys = Keys::get();
+			let keys = Keys::<T>::get();
 			let public = keys.get(heartbeat.authority_index as usize);
 			if let (true, Some(public)) = (!exists, public) {
 				let signature_valid = heartbeat.using_encoded(|encoded_heartbeat| {
@@ -240,7 +261,7 @@ decl_module! {
 				});
 				ensure!(signature_valid, "Invalid heartbeat signature.");
 
-				Self::deposit_event(Event::HeartbeatReceived(public.clone()));
+				Self::deposit_event(Event::<T>::HeartbeatReceived(public.clone()));
 
 				let network_state = heartbeat.network_state.encode();
 				<ReceivedHeartbeats>::insert(
@@ -297,8 +318,8 @@ impl<T: Trait> Module<T> {
 
 	fn do_gossip_at(block_number: T::BlockNumber) -> Result<(), OffchainErr> {
 		// we run only when a local authority key is configured
-		let authorities = Keys::get();
-		let mut local_keys = app::Public::all();
+		let authorities = Keys::<T>::get();
+		let mut local_keys = T::AuthorityId::all();
 		local_keys.sort();
 
 		for (authority_index, key) in authorities.into_iter()
@@ -389,27 +410,27 @@ impl<T: Trait> Module<T> {
 		}
 	}
 
-	fn initialize_keys(keys: &[AuthorityId]) {
+	fn initialize_keys(keys: &[T::AuthorityId]) {
 		if !keys.is_empty() {
-			assert!(Keys::get().is_empty(), "Keys are already initialized!");
-			Keys::put_ref(keys);
+			assert!(Keys::<T>::get().is_empty(), "Keys are already initialized!");
+			Keys::<T>::put_ref(keys);
 		}
 	}
 }
 
 impl<T: Trait> session::OneSessionHandler<T::AccountId> for Module<T> {
 
-	type Key = AuthorityId;
+	type Key = T::AuthorityId;
 
 	fn on_genesis_session<'a, I: 'a>(validators: I)
-		where I: Iterator<Item=(&'a T::AccountId, AuthorityId)>
+		where I: Iterator<Item=(&'a T::AccountId, T::AuthorityId)>
 	{
 		let keys = validators.map(|x| x.1).collect::<Vec<_>>();
 		Self::initialize_keys(&keys);
 	}
 
 	fn on_new_session<'a, I: 'a>(_changed: bool, validators: I, _queued_validators: I)
-		where I: Iterator<Item=(&'a T::AccountId, AuthorityId)>
+		where I: Iterator<Item=(&'a T::AccountId, T::AuthorityId)>
 	{
 		// Reset heartbeats
 		<ReceivedHeartbeats>::remove_prefix(&<session::Module<T>>::current_index());
@@ -418,7 +439,7 @@ impl<T: Trait> session::OneSessionHandler<T::AccountId> for Module<T> {
 		<GossipAt<T>>::put(<system::Module<T>>::block_number());
 
 		// Remember who the authorities are for the new session.
-		Keys::put(validators.map(|x| x.1).collect::<Vec<_>>());
+		Keys::<T>::put(validators.map(|x| x.1).collect::<Vec<_>>());
 	}
 
 	fn on_before_session_ending() {
@@ -426,7 +447,7 @@ impl<T: Trait> session::OneSessionHandler<T::AccountId> for Module<T> {
 
 		let current_session = <session::Module<T>>::current_index();
 
-		let keys = Keys::get();
+		let keys = Keys::<T>::get();
 		let current_elected = T::CurrentElectedSet::current_elected_set();
 
 		// The invariant is that these two are of the same length.
@@ -481,7 +502,7 @@ impl<T: Trait> srml_support::unsigned::ValidateUnsigned for Module<T> {
 			}
 
 			// verify that the incoming (unverified) pubkey is actually an authority id
-			let keys = Keys::get();
+			let keys = Keys::<T>::get();
 			let authority_id = match keys.get(heartbeat.authority_index as usize) {
 				Some(id) => id,
 				None => return TransactionValidity::Invalid(ApplyError::BadSignature as i8),
diff --git a/srml/session/src/lib.rs b/srml/session/src/lib.rs
index f8e13d529b875..c474962c650db 100644
--- a/srml/session/src/lib.rs
+++ b/srml/session/src/lib.rs
@@ -170,6 +170,12 @@ impl<
 pub trait OnSessionEnding<ValidatorId> {
 	/// Handle the fact that the session is ending, and optionally provide the new validator set.
 	///
+	/// Even if the validator-set is the same as before, if any underlying economic
+	/// conditions have changed (i.e. stake-weights), the new validator set must be returned.
+	/// This is necessary for consensus engines making use of the session module to
+	/// issue a validator-set change so misbehavior can be provably associated with the new
+	/// economic conditions as opposed to the old.
+	///
 	/// `ending_index` is the index of the currently ending session.
 	/// The returned validator set, if any, will not be applied until `will_apply_at`.
 	/// `will_apply_at` is guaranteed to be at least `ending_index + 1`, since session indices don't
@@ -192,7 +198,11 @@ pub trait SessionHandler<ValidatorId> {
 	/// should provide the same validator set.
 	fn on_genesis_session<Ks: OpaqueKeys>(validators: &[(ValidatorId, Ks)]);
 
-	/// Session set has changed; act appropriately.
+	/// Session set has changed; act appropriately. Note that this can be called
+	/// before initialization of your module.
+	///
+	/// `changed` is true whenever any of the session keys or underlying economic
+	/// identities or weightings behind those keys has changed.
 	fn on_new_session<Ks: OpaqueKeys>(
 		changed: bool,
 		validators: &[(ValidatorId, Ks)],
@@ -217,11 +227,19 @@ pub trait OneSessionHandler<ValidatorId> {
 	fn on_genesis_session<'a, I: 'a>(validators: I)
 		where I: Iterator<Item=(&'a ValidatorId, Self::Key)>, ValidatorId: 'a;
 
-	/// Session set has changed; act appropriately.
+	/// Session set has changed; act appropriately. Note that this can be called
+	/// before initialization of your module.
+	///
+	/// `changed` is true when at least one of the session keys
+	/// or the underlying economic identities/distribution behind one the
+	/// session keys has changed, false otherwise.
+	///
+	/// The `validators` are the validators of the incoming session, and `queued_validators`
+	/// will follow.
 	fn on_new_session<'a, I: 'a>(
-		_changed: bool,
-		_validators: I,
-		_queued_validators: I
+		changed: bool,
+		validators: I,
+		queued_validators: I,
 	) where I: Iterator<Item=(&'a ValidatorId, Self::Key)>, ValidatorId: 'a;
 
 
@@ -341,10 +359,8 @@ decl_storage! {
 		/// Current index of the session.
 		CurrentIndex get(current_index): SessionIndex;
 
-		/// True if anything has changed in this session.
-		Changed: bool;
-
-		/// Queued keys changed.
+		/// True if the underlying economic identities or weighting behind the validators
+		/// has changed in the queued validator set.
 		QueuedChanged: bool;
 
 		/// The queued keys for the next session. When the next session begins, these keys
@@ -443,13 +459,10 @@ decl_module! {
 
 			Self::do_set_keys(&who, keys)?;
 
-			// Something changed.
-			Changed::put(true);
-
 			Ok(())
 		}
 
-		/// Called when a block is finalized. Will rotate session if it is the last
+		/// Called when a block is initialized. Will rotate session if it is the last
 		/// block of the current session.
 		fn on_initialize(n: T::BlockNumber) {
 			if T::ShouldEndSession::should_end_session(n) {
@@ -467,7 +480,9 @@ impl<T: Trait> Module<T> {
 		let session_index = CurrentIndex::get();
 
 		let changed = QueuedChanged::get();
-		let mut next_changed = Changed::take();
+
+		// Inform the session handlers that a session is going to end.
+		T::SessionHandler::on_before_session_ending();
 
 		// Get queued session keys and validators.
 		let session_keys = <QueuedKeys<T>>::get();
@@ -479,12 +494,16 @@ impl<T: Trait> Module<T> {
 		let applied_at = session_index + 2;
 
 		// Get next validator set.
-		let maybe_validators = T::OnSessionEnding::on_session_ending(session_index, applied_at);
-		let next_validators = if let Some(validators) = maybe_validators {
-			next_changed = true;
-			validators
+		let maybe_next_validators = T::OnSessionEnding::on_session_ending(session_index, applied_at);
+		let (next_validators, next_identities_changed)
+			= if let Some(validators) = maybe_next_validators
+		{
+			// NOTE: as per the documentation on `OnSessionEnding`, we consider
+			// the validator set as having changed even if the validators are the
+			// same as before, as underlying economic conditions may have changed.
+			(validators, true)
 		} else {
-			<Validators<T>>::get()
+			(<Validators<T>>::get(), false)
 		};
 
 		// Increment session index.
@@ -492,9 +511,34 @@ impl<T: Trait> Module<T> {
 		CurrentIndex::put(session_index);
 
 		// Queue next session keys.
-		let queued_amalgamated = next_validators.into_iter()
-			.map(|a| { let k = Self::load_keys(&a).unwrap_or_default(); (a, k) })
-			.collect::<Vec<_>>();
+		let (queued_amalgamated, next_changed) = {
+			// until we are certain there has been a change, iterate the prior
+			// validators along with the current and check for changes
+			let mut changed = next_identities_changed;
+
+			let mut now_session_keys = session_keys.iter();
+			let mut check_next_changed = |keys: &T::Keys| {
+				if changed { return }
+				// since a new validator set always leads to `changed` starting
+				// as true, we can ensure that `now_session_keys` and `next_validators`
+				// have the same length. this function is called once per iteration.
+				if let Some(&(_, ref old_keys)) = now_session_keys.next() {
+					if old_keys != keys {
+						changed = true;
+						return
+					}
+				}
+			};
+			let queued_amalgamated = next_validators.into_iter()
+				.map(|a| {
+					let k = Self::load_keys(&a).unwrap_or_default();
+					check_next_changed(&k);
+					(a, k)
+				})
+				.collect::<Vec<_>>();
+
+			(queued_amalgamated, changed)
+		};
 
 		<QueuedKeys<T>>::put(queued_amalgamated.clone());
 		QueuedChanged::put(next_changed);
@@ -503,13 +547,16 @@ impl<T: Trait> Module<T> {
 		Self::deposit_event(Event::NewSession(session_index));
 
 		// Tell everyone about the new session keys.
-		T::SessionHandler::on_new_session::<T::Keys>(changed, &session_keys, &queued_amalgamated);
+		T::SessionHandler::on_new_session::<T::Keys>(
+			changed,
+			&session_keys,
+			&queued_amalgamated,
+		);
 	}
 
 	/// Disable the validator of index `i`.
 	pub fn disable_index(i: usize) {
 		T::SessionHandler::on_disabled(i);
-		Changed::put(true);
 	}
 
 	/// Disable the validator identified by `c`. (If using with the staking module, this would be
@@ -554,8 +601,6 @@ impl<T: Trait> Module<T> {
 				let key_data = old_keys.get_raw(id);
 				Self::clear_key_owner(id, key_data);
 			}
-
-			Changed::put(true);
 		}
 	}
 
@@ -621,6 +666,7 @@ mod tests {
 	use mock::{
 		NEXT_VALIDATORS, SESSION_CHANGED, TEST_SESSION_CHANGED, authorities, force_new_session,
 		set_next_validators, set_session_length, session_changed, Test, Origin, System, Session,
+		reset_before_session_end_called, before_session_end_called,
 	};
 
 	fn new_test_ext() -> runtime_io::TestExternalities<Blake2Hasher> {
@@ -668,13 +714,13 @@ mod tests {
 			Session::on_free_balance_zero(&1);
 			assert_eq!(Session::load_keys(&1), None);
 			assert_eq!(Session::key_owner(id, UintAuthorityId(1).get_raw(id)), None);
-
-			assert!(Changed::get());
 		})
 	}
 
 	#[test]
 	fn authorities_should_track_validators() {
+		reset_before_session_end_called();
+
 		with_externalities(&mut new_test_ext(), || {
 			set_next_validators(vec![1, 2]);
 			force_new_session();
@@ -685,6 +731,8 @@ mod tests {
 			]);
 			assert_eq!(Session::validators(), vec![1, 2, 3]);
 			assert_eq!(authorities(), vec![UintAuthorityId(1), UintAuthorityId(2), UintAuthorityId(3)]);
+			assert!(before_session_end_called());
+			reset_before_session_end_called();
 
 			force_new_session();
 			initialize_block(2);
@@ -694,6 +742,8 @@ mod tests {
 			]);
 			assert_eq!(Session::validators(), vec![1, 2]);
 			assert_eq!(authorities(), vec![UintAuthorityId(1), UintAuthorityId(2)]);
+			assert!(before_session_end_called());
+			reset_before_session_end_called();
 
 			set_next_validators(vec![1, 2, 4]);
 			assert_ok!(Session::set_keys(Origin::signed(4), UintAuthorityId(4).into(), vec![]));
@@ -706,6 +756,7 @@ mod tests {
 			]);
 			assert_eq!(Session::validators(), vec![1, 2]);
 			assert_eq!(authorities(), vec![UintAuthorityId(1), UintAuthorityId(2)]);
+			assert!(before_session_end_called());
 
 			force_new_session();
 			initialize_block(4);
@@ -787,38 +838,63 @@ mod tests {
 
 	#[test]
 	fn session_changed_flag_works() {
+		reset_before_session_end_called();
+
 		with_externalities(&mut new_test_ext(), || {
 			TEST_SESSION_CHANGED.with(|l| *l.borrow_mut() = true);
 
 			force_new_session();
 			initialize_block(1);
 			assert!(!session_changed());
+			assert!(before_session_end_called());
+			reset_before_session_end_called();
 
 			force_new_session();
 			initialize_block(2);
 			assert!(!session_changed());
+			assert!(before_session_end_called());
+			reset_before_session_end_called();
 
 			Session::disable_index(0);
 			force_new_session();
 			initialize_block(3);
 			assert!(!session_changed());
+			assert!(before_session_end_called());
+			reset_before_session_end_called();
 
 			force_new_session();
 			initialize_block(4);
 			assert!(session_changed());
+			assert!(before_session_end_called());
+			reset_before_session_end_called();
 
 			force_new_session();
 			initialize_block(5);
 			assert!(!session_changed());
+			assert!(before_session_end_called());
+			reset_before_session_end_called();
 
 			assert_ok!(Session::set_keys(Origin::signed(2), UintAuthorityId(5).into(), vec![]));
 			force_new_session();
 			initialize_block(6);
 			assert!(!session_changed());
+			assert!(before_session_end_called());
+			reset_before_session_end_called();
 
+			// changing the keys of a validator leads to change.
+			assert_ok!(Session::set_keys(Origin::signed(69), UintAuthorityId(69).into(), vec![]));
 			force_new_session();
 			initialize_block(7);
 			assert!(session_changed());
+			assert!(before_session_end_called());
+			reset_before_session_end_called();
+
+			// while changing the keys of a non-validator does not.
+			force_new_session();
+			initialize_block(7);
+			assert!(!session_changed());
+			assert!(before_session_end_called());
+			reset_before_session_end_called();
 		});
 	}
 
diff --git a/srml/session/src/mock.rs b/srml/session/src/mock.rs
index c5608e1a54571..445076be65202 100644
--- a/srml/session/src/mock.rs
+++ b/srml/session/src/mock.rs
@@ -44,6 +44,7 @@ impl_outer_origin! {
 }
 
 thread_local! {
+	pub static VALIDATORS: RefCell<Vec<u64>> = RefCell::new(vec![1, 2, 3]);
 	pub static NEXT_VALIDATORS: RefCell<Vec<u64>> = RefCell::new(vec![1, 2, 3]);
 	pub static AUTHORITIES: RefCell<Vec<UintAuthorityId>> =
 		RefCell::new(vec![UintAuthorityId(1), UintAuthorityId(2), UintAuthorityId(3)]);
@@ -51,6 +52,9 @@ thread_local! {
 	pub static SESSION_LENGTH: RefCell<u64> = RefCell::new(2);
 	pub static SESSION_CHANGED: RefCell<bool> = RefCell::new(false);
 	pub static TEST_SESSION_CHANGED: RefCell<bool> = RefCell::new(false);
+	pub static DISABLED: RefCell<bool> = RefCell::new(false);
+	// Stores if `on_before_session_end` was called
+	pub static BEFORE_SESSION_END_CALLED: RefCell<bool> = RefCell::new(false);
 }
 
 pub struct TestShouldEndSession;
@@ -76,14 +80,27 @@ impl SessionHandler<u64> for TestSessionHandler {
 				.collect()
 		);
 	}
-	fn on_disabled(_validator_index: usize) {}
+	fn on_disabled(_validator_index: usize) {
+		DISABLED.with(|l| *l.borrow_mut() = true)
+	}
+	fn on_before_session_ending() {
+		BEFORE_SESSION_END_CALLED.with(|b| *b.borrow_mut() = true);
+	}
 }
 
 pub struct TestOnSessionEnding;
 impl OnSessionEnding<u64> for TestOnSessionEnding {
 	fn on_session_ending(_: SessionIndex, _: SessionIndex) -> Option<Vec<u64>> {
 		if !TEST_SESSION_CHANGED.with(|l| *l.borrow()) {
-			Some(NEXT_VALIDATORS.with(|l| l.borrow().clone()))
+			VALIDATORS.with(|v| {
+				let mut v = v.borrow_mut();
+				*v = NEXT_VALIDATORS.with(|l| l.borrow().clone());
+				Some(v.clone())
+			})
+		} else if DISABLED.with(|l| std::mem::replace(&mut *l.borrow_mut(), false)) {
+			// If there was a disabled validator, underlying conditions have changed
+			// so we return `Some`.
+			Some(VALIDATORS.with(|v| v.borrow().clone()))
 		} else {
 			None
 		}
@@ -92,16 +109,13 @@ impl OnSessionEnding<u64> for TestOnSessionEnding {
 
 #[cfg(feature = "historical")]
 impl crate::historical::OnSessionEnding<u64, u64> for TestOnSessionEnding {
-	fn on_session_ending(_: SessionIndex, _: SessionIndex)
+	fn on_session_ending(ending_index: SessionIndex, will_apply_at: SessionIndex)
 		-> Option<(Vec<u64>, Vec<(u64, u64)>)>
 	{
-		if !TEST_SESSION_CHANGED.with(|l| *l.borrow()) {
-			let last_validators = Session::validators();
-			let last_identifications = last_validators.into_iter().map(|v| (v, v)).collect();
-			Some((NEXT_VALIDATORS.with(|l| l.borrow().clone()), last_identifications))
-		} else {
-			None
-		}
+		let pair_with_ids = |vals: &[u64]| vals.iter().map(|&v| (v, v)).collect::<Vec<_>>();
+		<Self as OnSessionEnding<_>>::on_session_ending(ending_index, will_apply_at)
+			.map(|vals| (pair_with_ids(&vals), vals))
+			.map(|(ids, vals)| (vals, ids))
 	}
 }
 
@@ -125,8 +139,17 @@ pub fn set_next_validators(next: Vec<u64>) {
 	NEXT_VALIDATORS.with(|v| *v.borrow_mut() = next);
 }
 
+pub fn before_session_end_called() -> bool {
+	BEFORE_SESSION_END_CALLED.with(|b| *b.borrow())
+}
+
+pub fn reset_before_session_end_called() {
+	BEFORE_SESSION_END_CALLED.with(|b| *b.borrow_mut() = false);
+}
+
 #[derive(Clone, Eq, PartialEq)]
 pub struct Test;
+
 parameter_types! {
 	pub const BlockHashCount: u64 = 250;
 	pub const MaximumBlockWeight: u32 = 1024;
diff --git a/srml/staking/src/lib.rs b/srml/staking/src/lib.rs
index e7bb42c64dfe5..2e46d6b2b4a49 100644
--- a/srml/staking/src/lib.rs
+++ b/srml/staking/src/lib.rs
@@ -465,9 +465,6 @@ type ExpoMap<T> = BTreeMap<
 	Exposure<<T as system::Trait>::AccountId, BalanceOf<T>>
 >;
 
-pub const DEFAULT_SESSIONS_PER_ERA: u32 = 3;
-pub const DEFAULT_BONDING_DURATION: u32 = 1;
-
 /// Means for interacting with a specialized version of the `session` trait.
 ///
 /// This is needed because `Staking` sets the `ValidatorIdOf` of the `session::Trait`
@@ -1182,7 +1179,7 @@ impl<T: Trait> Module<T> {
 		let rewards = CurrentEraRewards::take();
 		let now = T::Time::now();
 		let previous_era_start = <CurrentEraStart<T>>::mutate(|v| {
-			rstd::mem::replace(v, now.clone())
+			rstd::mem::replace(v, now)
 		});
 		let era_duration = now - previous_era_start;
 		if !era_duration.is_zero() {
@@ -1355,6 +1352,10 @@ impl<T: Trait> Module<T> {
 			// Set the new validator set in sessions.
 			<CurrentElected<T>>::put(&elected_stashes);
 
+			// In order to keep the property required by `n_session_ending`
+			// that we must return the new validator set even if it's the same as the old,
+			// as long as any underlying economic conditions have changed, we don't attempt
+			// to do any optimization where we compare against the prior set.
 			(slot_stake, Some(elected_stashes))
 		} else {
 			// There were not enough candidates for even our minimal level of functionality.
diff --git a/srml/support/Cargo.toml b/srml/support/Cargo.toml
index 2befc11b19538..cf8c90993aef6 100644
--- a/srml/support/Cargo.toml
+++ b/srml/support/Cargo.toml
@@ -6,7 +6,7 @@ edition = "2018"
 
 [dependencies]
 serde = { version = "1.0", optional = true, features = ["derive"] }
-codec = { package = "parity-scale-codec", version = "1.0.0", default-features = false, features = ["derive"] }
+codec = { package = "parity-scale-codec", version = "1.0.5", default-features = false, features = ["derive"] }
 srml-metadata = { path = "../metadata", default-features = false }
 sr-std = { path = "../../core/sr-std", default-features = false }
 runtime_io = { package = "sr-io", path = "../../core/sr-io", default-features = false }
diff --git a/srml/support/procedural/src/storage/impls.rs b/srml/support/procedural/src/storage/impls.rs
index dd93663673514..d67bc5a116e9d 100644
--- a/srml/support/procedural/src/storage/impls.rs
+++ b/srml/support/procedural/src/storage/impls.rs
@@ -43,6 +43,8 @@ pub(crate) struct Impls<'a, I: Iterator<Item=syn::Meta>> {
 	pub instance_opts: &'a InstanceOpts,
 	pub type_infos: DeclStorageTypeInfos<'a>,
 	pub fielddefault: TokenStream2,
+	pub default_delegator_ident: syn::Ident,
+	pub default_delegator_return: TokenStream2,
 	pub prefix: String,
 	pub cratename: &'a syn::Ident,
 	pub name: &'a syn::Ident,
@@ -60,6 +62,8 @@ impl<'a, I: Iterator<Item=syn::Meta>> Impls<'a, I> {
 			instance_opts,
 			type_infos,
 			fielddefault,
+			default_delegator_ident,
+			default_delegator_return,
 			prefix,
 			name,
 			attrs,
@@ -116,6 +120,17 @@ impl<'a, I: Iterator<Item=syn::Meta>> Impls<'a, I> {
 
 		// generator for value
 		quote! {
+			#visibility struct #default_delegator_ident<#struct_trait>(
+				#scrate::rstd::marker::PhantomData<(#trait_and_instance)>
+			) #where_clause;
+			impl<#impl_trait> #scrate::traits::StorageDefault<#typ>
+				for #default_delegator_ident<#trait_and_instance> #where_clause
+			{
+				fn default() -> Option<#typ> {
+					#default_delegator_return
+				}
+			}
+
 			#( #[ #attrs ] )*
 			#visibility struct #name<#struct_trait>(
 				#scrate::rstd::marker::PhantomData<(#trait_and_instance)>
@@ -125,6 +140,7 @@ impl<'a, I: Iterator<Item=syn::Meta>> Impls<'a, I> {
 				for #name<#trait_and_instance> #where_clause
 			{
 				type Query = #value_type;
+				type Default = #default_delegator_ident<#trait_and_instance>;
 
 				/// Get the storage key.
 				fn key() -> &'static [u8] {
@@ -168,6 +184,8 @@ impl<'a, I: Iterator<Item=syn::Meta>> Impls<'a, I> {
 			instance_opts,
 			type_infos,
 			fielddefault,
+			default_delegator_ident,
+			default_delegator_return,
 			prefix,
 			name,
 			attrs,
@@ -230,6 +248,17 @@ impl<'a, I: Iterator<Item=syn::Meta>> Impls<'a, I> {
 
 		// generator for map
 		quote!{
+			#visibility struct #default_delegator_ident<#struct_trait>(
+				#scrate::rstd::marker::PhantomData<(#trait_and_instance)>
+			) #where_clause;
+			impl<#impl_trait> #scrate::traits::StorageDefault<#typ>
+				for #default_delegator_ident<#trait_and_instance> #where_clause
+			{
+				fn default() -> Option<#typ> {
+					#default_delegator_return
+				}
+			}
+
 			#( #[ #attrs ] )*
 			#visibility struct #name<#struct_trait>(
 				#scrate::rstd::marker::PhantomData<(#trait_and_instance)>
@@ -239,8 +268,8 @@ impl<'a, I: Iterator<Item=syn::Meta>> Impls<'a, I> {
 				for #name<#trait_and_instance> #where_clause
 			{
 				type Query = #value_type;
-
 				type Hasher = #scrate::#hasher;
+				type Default = #default_delegator_ident<#trait_and_instance>;
 
 				/// Get the prefix key in storage.
 				fn prefix() -> &'static [u8] {
@@ -283,6 +312,10 @@ impl<'a, I: Iterator<Item=syn::Meta>> Impls<'a, I> {
 			impl<#impl_trait> #scrate::storage::hashed::generator::AppendableStorageMap<#kty, #typ>
 				for #name<#trait_and_instance> #where_clause
 			{}
+
+			impl<#impl_trait> #scrate::storage::hashed::generator::DecodeLengthStorageMap<#kty, #typ>
+				for #name<#trait_and_instance> #where_clause
+			{}
 		}
 	}
 
@@ -295,6 +328,8 @@ impl<'a, I: Iterator<Item=syn::Meta>> Impls<'a, I> {
 			instance_opts,
 			type_infos,
 			fielddefault,
+			default_delegator_ident,
+			default_delegator_return,
 			prefix,
 			name,
 			attrs,
@@ -567,12 +602,23 @@ impl<'a, I: Iterator<Item=syn::Meta>> Impls<'a, I> {
 
 			#structure
 
+			#visibility struct #default_delegator_ident<#struct_trait>(
+				#scrate::rstd::marker::PhantomData<(#trait_and_instance)>
+			) #where_clause;
+			impl<#impl_trait> #scrate::traits::StorageDefault<#typ>
+				for #default_delegator_ident<#trait_and_instance> #where_clause
+			{
+				fn default() -> Option<#typ> {
+					#default_delegator_return
+				}
+			}
+
 			impl<#impl_trait> #scrate::storage::hashed::generator::StorageMap<#kty, #typ>
 				for #name<#trait_and_instance> #where_clause
 			{
 				type Query = #value_type;
-
 				type Hasher = #scrate::#hasher;
+				type Default = #default_delegator_ident<#trait_and_instance>;
 
 				/// Get the prefix key in storage.
 				fn prefix() -> &'static [u8] {
@@ -666,6 +712,42 @@ impl<'a, I: Iterator<Item=syn::Meta>> Impls<'a, I> {
 					#mutate_impl;
 					ret
 				}
+
+				// Swap must be overriden not to break links.
+				fn swap<S: #scrate::HashedStorage<Self::Hasher>>(
+					key1: &#kty,
+					key2: &#kty,
+					storage: &mut S,
+				) {
+					use self::#inner_module::Utils;
+
+					let final_key1 = &*#as_map::key_for(key1);
+					let final_key2 = &*#as_map::key_for(key2);
+					let full_value_1 = Self::read_with_linkage(storage, final_key1);
+					let full_value_2 = Self::read_with_linkage(storage, final_key2);
+
+					match (full_value_1, full_value_2) {
+						// Just keep linkage in order and only swap values.
+						(Some((value1, linkage1)), Some((value2, linkage2))) => {
+							storage.put(final_key1, &(value2, linkage1));
+							storage.put(final_key2, &(value1, linkage2));
+						}
+						// Remove key and insert the new one.
+						(Some((value, linkage)), None) => {
+							#as_map::remove(key1, storage);
+							let linkage = Self::new_head_linkage(storage, key2);
+							storage.put(final_key2, &(value, linkage));
+						}
+						// Remove key and insert the new one.
+						(None, Some((value, linkage))) => {
+							#as_map::remove(key2, storage);
+							let linkage = Self::new_head_linkage(storage, key1);
+							storage.put(final_key1, &(value, linkage));
+						}
+						// No-op.
+						(None, None) => (),
+					}
+				}
 			}
 
 			impl<#impl_trait> #scrate::storage::hashed::generator::EnumerableStorageMap<#kty, #typ>
@@ -694,6 +776,10 @@ impl<'a, I: Iterator<Item=syn::Meta>> Impls<'a, I> {
 					})
 				}
 			}
+
+			impl<#impl_trait> #scrate::storage::hashed::generator::DecodeLengthStorageMap<#kty, #typ>
+				for #name<#trait_and_instance> #where_clause
+			{}
 		}
 	}
 
diff --git a/srml/support/procedural/src/storage/transformation.rs b/srml/support/procedural/src/storage/transformation.rs
index d378907cb1e72..039bf8c8f611b 100644
--- a/srml/support/procedural/src/storage/transformation.rs
+++ b/srml/support/procedural/src/storage/transformation.rs
@@ -35,7 +35,7 @@ use syn::{
 	},
 	parse_macro_input,
 };
-use quote::quote;
+use quote::{quote, quote_spanned};
 
 use super::*;
 
@@ -417,7 +417,16 @@ fn decl_store_extra_genesis(
 					}
 					assimilate_require_generic |= ext::expr_contains_ident(&expr.content, traitinstance);
 					let content = &expr.content;
-					scall = quote!( ( #content ) );
+					scall = quote_spanned! { expr.span() =>
+						let scall: fn(
+							&mut (
+								#scrate::sr_primitives::StorageOverlay,
+								#scrate::sr_primitives::ChildrenStorageOverlay
+							),
+							&Self
+						) = #content;
+						scall
+					};
 					has_scall = true;
 				},
 			}
@@ -753,10 +762,26 @@ fn decl_storage_items(
 		} = sline;
 
 		let type_infos = get_type_infos(storage_type);
+		let fielddefault = default_value.inner
+			.as_ref()
+			.map(|d| &d.expr)
+			.map(|d| quote!( #d ))
+			.unwrap_or_else(|| quote!{ Default::default() });
 		let kind = type_infos.kind.clone();
 		// Propagate doc attributes.
 		let attrs = attrs.inner.iter().filter_map(|a| a.parse_meta().ok()).filter(|m| m.name() == "doc");
 
+		// create default value delegator
+		let default_delegator_ident = Ident::new(
+			&format!("{}{}", name.to_string(), "DefaultDelegator"),
+			proc_macro2::Span::call_site(),
+		);
+		let default_delegator_return = if !type_infos.is_option {
+			quote! { Some(#fielddefault) }
+		} else {
+			quote! { #fielddefault }
+		};
+
 		let i = impls::Impls {
 			scrate,
 			visibility,
@@ -765,8 +790,9 @@ fn decl_storage_items(
 			traittype,
 			instance_opts,
 			type_infos,
-			fielddefault: default_value.inner.as_ref().map(|d| &d.expr).map(|d| quote!( #d ))
-				.unwrap_or_else(|| quote!{ Default::default() }),
+			fielddefault,
+			default_delegator_ident,
+			default_delegator_return,
 			prefix: build_prefix(cratename, name),
 			name,
 			attrs,
diff --git a/srml/support/src/lib.rs b/srml/support/src/lib.rs
index 5623cab70f2ab..9ebd848fca4c4 100644
--- a/srml/support/src/lib.rs
+++ b/srml/support/src/lib.rs
@@ -62,7 +62,8 @@ mod double_map;
 pub mod traits;
 
 pub use self::storage::{
-	StorageValue, StorageMap, EnumerableStorageMap, StorageDoubleMap, AppendableStorageMap
+	StorageValue, StorageMap, EnumerableStorageMap, StorageDoubleMap, AppendableStorageMap,
+	DecodeLengthStorageMap,
 };
 pub use self::hashable::Hashable;
 pub use self::dispatch::{Parameter, Dispatchable, Callable, IsSubType};
@@ -342,6 +343,35 @@ mod tests {
 		});
 	}
 
+	#[test]
+	fn linked_map_swap_works() {
+		with_externalities(&mut new_test_ext(), || {
+			OptionLinkedMap::insert(0, 0);
+			OptionLinkedMap::insert(1, 1);
+			OptionLinkedMap::insert(2, 2);
+			OptionLinkedMap::insert(3, 3);
+
+			let collect = || OptionLinkedMap::enumerate().collect::<Vec<_>>();
+			assert_eq!(collect(), vec![(3, 3), (2, 2), (1, 1), (0, 0)]);
+
+			// Two existing
+			OptionLinkedMap::swap(1, 2);
+			assert_eq!(collect(), vec![(3, 3), (2, 1), (1, 2), (0, 0)]);
+
+			// Back to normal
+			OptionLinkedMap::swap(2, 1);
+			assert_eq!(collect(), vec![(3, 3), (2, 2), (1, 1), (0, 0)]);
+
+			// Left existing
+			OptionLinkedMap::swap(2, 5);
+			assert_eq!(collect(), vec![(5, 2), (3, 3), (1, 1), (0, 0)]);
+
+			// Right existing
+			OptionLinkedMap::swap(5, 2);
+			assert_eq!(collect(), vec![(2, 2), (3, 3), (1, 1), (0, 0)]);
+		});
+	}
+
 	#[test]
 	fn linked_map_basic_insert_remove_should_work() {
 		with_externalities(&mut new_test_ext(), || {
diff --git a/srml/support/src/storage/hashed/generator.rs b/srml/support/src/storage/hashed/generator.rs
index f8b8fb5483e1e..27b459e3ffa0e 100644
--- a/srml/support/src/storage/hashed/generator.rs
+++ b/srml/support/src/storage/hashed/generator.rs
@@ -14,12 +14,14 @@
 // You should have received a copy of the GNU General Public License
 // along with Substrate.  If not, see <http://www.gnu.org/licenses/>.
 
-//! Abstract storage to use on HashedStorage trait
+//! Abstract storage to use on HashedStorage trait. Please refer to the
+//! [top level docs](../../index.html) for more detailed documentation about storage traits and functions.
 
 use crate::codec::{self, Encode};
-use crate::rstd::prelude::{Vec, Box};
+use crate::rstd::{prelude::{Vec, Box}, iter::FromIterator};
 #[cfg(feature = "std")]
 use crate::storage::unhashed::generator::UnhashedStorage;
+use crate::traits::{StorageDefault, Len};
 use runtime_io::{twox_64, twox_128, blake2_128, twox_256, blake2_256};
 
 pub trait StorageHasher: 'static {
@@ -164,6 +166,9 @@ impl<H: StorageHasher> HashedStorage<H> for sr_primitives::StorageOverlay {
 pub trait StorageValue<T: codec::Codec> {
 	/// The type that get/take returns.
 	type Query;
+	/// Something that can provide the default value of this storage type.
+	type Default: StorageDefault<T>;
+
 
 	/// Get the storage key.
 	fn key() -> &'static [u8];
@@ -202,24 +207,75 @@ pub trait StorageValue<T: codec::Codec> {
 	/// Append the given items to the value in the storage.
 	///
 	/// `T` is required to implement `codec::EncodeAppend`.
-	fn append<S: HashedStorage<Twox128>, I: codec::Encode>(
-		items: &[I], storage: &mut S
-	) -> Result<(), &'static str> where T: codec::EncodeAppend<Item=I> {
+	fn append<'a, S, I, R>(
+		items: R,
+		storage: &mut S,
+	) -> Result<(), &'static str> where
+		S: HashedStorage<Twox128>,
+		I: 'a + codec::Encode,
+		T: codec::EncodeAppend<Item=I>,
+		R: IntoIterator<Item=&'a I>,
+		R::IntoIter: ExactSizeIterator,
+	{
 		let new_val = <T as codec::EncodeAppend>::append(
-			storage.get_raw(Self::key()).unwrap_or_default(),
+			// if the key exists, directly append to it.
+			storage.get_raw(Self::key()).unwrap_or_else(|| {
+				// otherwise, try and read a proper __provided__ default.
+				Self::Default::default().map(|v| v.encode())
+					// or just use the Rust's `default()` value.
+					.unwrap_or_default()
+			}),
 			items,
 		).map_err(|_| "Could not append given item")?;
 		storage.put_raw(Self::key(), &new_val);
 		Ok(())
 	}
+
+	/// Safely append the given items to the value in the storage. If a codec error occurs, then the
+	/// old (presumably corrupt) value is replaced with the given `items`.
+	///
+	/// `T` is required to implement `codec::EncodeAppend`.
+	fn append_or_put<'a, S, I, R>(
+		items: R,
+		storage: &mut S,
+	) where
+		S: HashedStorage<Twox128>,
+		I: 'a + codec::Encode + Clone,
+		T: codec::EncodeAppend<Item=I> + FromIterator<I>,
+		R: IntoIterator<Item=&'a I> + Clone,
+		R::IntoIter: ExactSizeIterator,
+	{
+		Self::append(items.clone(), storage)
+			.unwrap_or_else(|_| Self::put(&items.into_iter().cloned().collect(), storage));
+	}
+
+	/// Read the length of the value in a fast way, without decoding the entire value.
+	///
+	/// `T` is required to implement `Codec::DecodeLength`.
+	///
+	/// Note that `0` is returned as the default value if no encoded value exists at the given key.
+	/// Therefore, this function cannot be used as a sign of _existence_. use the `::exists()`
+	/// function for this purpose.
+	fn decode_len<S: HashedStorage<Twox128>>(storage: &mut S) -> Result<usize, &'static str>
+		where T: codec::DecodeLength, T: Len
+	{
+		// attempt to get the length directly.
+		if let Some(k) = storage.get_raw(Self::key()) {
+			<T as codec::DecodeLength>::len(&k).map_err(|e| e.what())
+		} else {
+			Ok(Self::Default::default().map(|v| v.len()).unwrap_or(0))
+		}
+	}
 }
 
 /// A strongly-typed map in storage.
 pub trait StorageMap<K: codec::Codec, V: codec::Codec> {
 	/// The type that get/take returns.
 	type Query;
-
+	/// Hasher type
 	type Hasher: StorageHasher;
+	/// Something that can provide the default value of this storage type.
+	type Default: StorageDefault<V>;
 
 	/// Get the prefix key in storage.
 	fn prefix() -> &'static [u8];
@@ -295,16 +351,69 @@ pub trait EnumerableStorageMap<K: codec::Codec, V: codec::Codec>: StorageMap<K,
 pub trait AppendableStorageMap<K: codec::Codec, V: codec::Codec>: StorageMap<K, V> {
 	/// Append the given items to the value in the storage.
 	///
-	/// `T` is required to implement `codec::EncodeAppend`.
-	fn append<S: HashedStorage<Self::Hasher>, I: codec::Encode>(
-		key : &K, items: &[I], storage: &mut S
-	) -> Result<(), &'static str> where V: codec::EncodeAppend<Item=I> {
+	/// `V` is required to implement `codec::EncodeAppend`.
+	fn append<'a, S, I, R>(
+		key : &K,
+		items: R,
+		storage: &mut S,
+	) -> Result<(), &'static str> where
+		S: HashedStorage<Self::Hasher>,
+		I: 'a + codec::Encode,
+		V: codec::EncodeAppend<Item=I>,
+		R: IntoIterator<Item=&'a I> + Clone,
+		R::IntoIter: ExactSizeIterator,
+	{
 		let k = Self::key_for(key);
 		let new_val = <V as codec::EncodeAppend>::append(
-			storage.get_raw(&k[..]).unwrap_or_default(),
+			storage.get_raw(&k[..]).unwrap_or_else(|| {
+				// otherwise, try and read a proper __provided__ default.
+				Self::Default::default().map(|v| v.encode())
+					// or just use the default value.
+					.unwrap_or_default()
+			}),
 			items,
 		).map_err(|_| "Could not append given item")?;
 		storage.put_raw(&k[..], &new_val);
 		Ok(())
 	}
+
+	/// Safely append the given items to the value in the storage. If a codec error occurs, then the
+	/// old (presumably corrupt) value is replaced with the given `items`.
+	///
+	/// `T` is required to implement `codec::EncodeAppend`.
+	fn append_or_insert<'a, S, I, R>(
+		key : &K,
+		items: R,
+		storage: &mut S,
+	) where
+		S: HashedStorage<Self::Hasher>,
+		I: 'a + codec::Encode + Clone,
+		V: codec::EncodeAppend<Item=I> + crate::rstd::iter::FromIterator<I>,
+		R: IntoIterator<Item=&'a I> + Clone,
+		R::IntoIter: ExactSizeIterator,
+	{
+		Self::append(key, items.clone(), storage)
+			.unwrap_or_else(|_| Self::insert(key, &items.into_iter().cloned().collect(), storage));
+	}
+}
+
+/// A storage map with a decodable length.
+pub trait DecodeLengthStorageMap<K: codec::Codec, V: codec::Codec>: StorageMap<K, V> {
+	/// Read the length of the value in a fast way, without decoding the entire value.
+	///
+	/// `T` is required to implement `Codec::DecodeLength`.
+	///
+	/// Note that `0` is returned as the default value if no encoded value exists at the given key.
+	/// Therefore, this function cannot be used as a sign of _existence_. use the `::exists()`
+	/// function for this purpose.
+	fn decode_len<S: HashedStorage<Self::Hasher>>(key: &K, storage: &mut S) -> Result<usize, &'static str>
+		where V: codec::DecodeLength, V: Len
+	{
+		let k = Self::key_for(key);
+		if let Some(v) = storage.get_raw(&k[..]) {
+			<V as codec::DecodeLength>::len(&v).map_err(|e| e.what())
+		} else {
+			Ok(Self::Default::default().map(|v| v.len()).unwrap_or(0))
+		}
+	}
 }
diff --git a/srml/support/src/storage/mod.rs b/srml/support/src/storage/mod.rs
index 385fad42eb260..aa3faee87852d 100644
--- a/srml/support/src/storage/mod.rs
+++ b/srml/support/src/storage/mod.rs
@@ -17,10 +17,11 @@
 //! Stuff to do with the runtime's storage.
 
 use crate::rstd::prelude::*;
-use crate::rstd::borrow::Borrow;
+use crate::rstd::{borrow::Borrow, iter::FromIterator};
 use codec::{Codec, Encode, Decode, KeyedVec, EncodeAppend};
 use hashed::generator::{HashedStorage, StorageHasher};
 use unhashed::generator::UnhashedStorage;
+use crate::traits::{StorageDefault, Len};
 
 #[macro_use]
 pub mod storage_items;
@@ -107,6 +108,8 @@ impl UnhashedStorage for RuntimeStorage {
 pub trait StorageValue<T: Codec> {
 	/// The type that get/take return.
 	type Query;
+	/// Something that can provide the default value of this storage type.
+	type Default: StorageDefault<T>;
 
 	/// Get the storage key.
 	fn key() -> &'static [u8];
@@ -136,12 +139,39 @@ pub trait StorageValue<T: Codec> {
 	/// Append the given item to the value in the storage.
 	///
 	/// `T` is required to implement `codec::EncodeAppend`.
-	fn append<I: Encode>(items: &[I]) -> Result<(), &'static str>
-		where T: EncodeAppend<Item=I>;
+	fn append<'a, I, R>(items: R) -> Result<(), &'static str> where
+		I: 'a + Encode,
+		T: EncodeAppend<Item=I>,
+		R: IntoIterator<Item=&'a I>,
+		R::IntoIter: ExactSizeIterator;
+
+	/// Append the given items to the value in the storage.
+	///
+	/// `T` is required to implement `Codec::EncodeAppend`.
+	///
+	/// Upon any failure, it replaces `items` as the new value (assuming that the previous stored
+	/// data is simply corrupt and no longer usable).
+	///
+	/// ### WARNING
+	///
+	/// use with care; if your use-case is not _exactly_ as what this function is doing,
+	/// you should use append and sensibly handle failure within the runtime code if it happens.
+	fn append_or_put<'a, I, R>(items: R) where
+		I: 'a + Encode + Clone,
+		T: EncodeAppend<Item=I> + FromIterator<I>,
+		R: IntoIterator<Item=&'a I> + Clone,
+		R::IntoIter: ExactSizeIterator;
+
+	/// Read the length of the value in a fast way, without decoding the entire value.
+	///
+	/// `T` is required to implement `Codec::DecodeLength`.
+	fn decode_len() -> Result<usize, &'static str>
+		where T: codec::DecodeLength, T: Len;
 }
 
 impl<T: Codec, U> StorageValue<T> for U where U: hashed::generator::StorageValue<T> {
 	type Query = U::Query;
+	type Default = U::Default;
 
 	fn key() -> &'static [u8] {
 		<U as hashed::generator::StorageValue<T>>::key()
@@ -167,17 +197,35 @@ impl<T: Codec, U> StorageValue<T> for U where U: hashed::generator::StorageValue
 	fn take() -> Self::Query {
 		U::take(&mut RuntimeStorage)
 	}
-	fn append<I: Encode>(items: &[I]) -> Result<(), &'static str>
-		where T: EncodeAppend<Item=I>
+	fn append<'a, I, R>(items: R) -> Result<(), &'static str> where
+		I: 'a + Encode,
+		T: EncodeAppend<Item=I>,
+		R: IntoIterator<Item=&'a I>,
+		R::IntoIter: ExactSizeIterator,
 	{
 		U::append(items, &mut RuntimeStorage)
 	}
+	fn append_or_put<'a, I, R>(items: R) where
+		I: 'a + Encode + Clone,
+		T: EncodeAppend<Item=I> + FromIterator<I>,
+		R: IntoIterator<Item=&'a I> + Clone,
+		R::IntoIter: ExactSizeIterator,
+	{
+		U::append_or_put(items, &mut RuntimeStorage)
+	}
+	fn decode_len() -> Result<usize, &'static str>
+		where T: codec::DecodeLength, T: Len
+	{
+		U::decode_len(&mut RuntimeStorage)
+	}
 }
 
 /// A strongly-typed map in storage.
 pub trait StorageMap<K: Codec, V: Codec> {
 	/// The type that get/take return.
 	type Query;
+	/// Something that can provide the default value of this storage type.
+	type Default: StorageDefault<V>;
 
 	/// Get the prefix key in storage.
 	fn prefix() -> &'static [u8];
@@ -213,6 +261,7 @@ pub trait StorageMap<K: Codec, V: Codec> {
 
 impl<K: Codec, V: Codec, U> StorageMap<K, V> for U where U: hashed::generator::StorageMap<K, V> {
 	type Query = U::Query;
+	type Default = U::Default;
 
 	fn prefix() -> &'static [u8] {
 		<U as hashed::generator::StorageMap<K, V>>::prefix()
@@ -260,18 +309,85 @@ pub trait AppendableStorageMap<K: Codec, V: Codec>: StorageMap<K, V> {
 	/// Append the given item to the value in the storage.
 	///
 	/// `T` is required to implement `codec::EncodeAppend`.
-	fn append<KeyArg: Borrow<K>, I: Encode>(key: KeyArg, items: &[I]) -> Result<(), &'static str>
-		where V: EncodeAppend<Item=I>;
+	fn append<'a, KeyArg, I, R>(
+		key: KeyArg,
+		items: R,
+	) -> Result<(), &'static str> where
+		KeyArg: Borrow<K>,
+		I: 'a + codec::Encode,
+		V: EncodeAppend<Item=I>,
+		R: IntoIterator<Item=&'a I> + Clone,
+		R::IntoIter: ExactSizeIterator;
+
+	/// Append the given items to the value in the storage.
+	///
+	/// `T` is required to implement `codec::EncodeAppend`.
+	///
+	/// Upon any failure, it replaces `items` as the new value (assuming that the previous stored
+	/// data is simply corrupt and no longer usable).
+	///
+	/// WARNING: use with care; if your use-case is not _exactly_ as what this function is doing,
+	/// you should use append and sensibly handle failure within the runtime code if it happens.
+	fn append_or_insert<'a, KeyArg, I, R>(
+		key: KeyArg,
+		items: R,
+	) where
+		KeyArg: Borrow<K>,
+		I: 'a + codec::Encode + Clone,
+		V: codec::EncodeAppend<Item=I> + FromIterator<I>,
+		R: IntoIterator<Item=&'a I> + Clone,
+		R::IntoIter: ExactSizeIterator;
 }
 
 impl<K: Codec, V: Codec, U> AppendableStorageMap<K, V> for U
 	where U: hashed::generator::AppendableStorageMap<K, V>
 {
-	fn append<KeyArg: Borrow<K>, I: Encode>(key: KeyArg, items: &[I]) -> Result<(), &'static str>
-		where V: EncodeAppend<Item=I>
+	fn append<'a, KeyArg, I, R>(
+		key: KeyArg,
+		items: R,
+	) -> Result<(), &'static str> where
+		KeyArg: Borrow<K>,
+		I: 'a + codec::Encode,
+		V: EncodeAppend<Item=I>,
+		R: IntoIterator<Item=&'a I> + Clone,
+		R::IntoIter: ExactSizeIterator,
 	{
 		U::append(key.borrow(), items, &mut RuntimeStorage)
 	}
+
+	fn append_or_insert<'a, KeyArg, I, R>(
+		key: KeyArg,
+		items: R,
+	) where
+		KeyArg: Borrow<K>,
+		I: 'a + codec::Encode + Clone,
+		V: codec::EncodeAppend<Item=I> + FromIterator<I>,
+		R: IntoIterator<Item=&'a I> + Clone,
+		R::IntoIter: ExactSizeIterator,
+	{
+		U::append_or_insert(key.borrow(), items, &mut RuntimeStorage)
+	}
+}
+
+/// A storage map with a decodable length.
+pub trait DecodeLengthStorageMap<K: Codec, V: Codec>: StorageMap<K, V> {
+	/// Read the length of the value in a fast way, without decoding the entire value.
+	///
+	/// `T` is required to implement `Codec::DecodeLength`.
+	///
+	/// Has the same logic as [`StorageValue`](trait.StorageValue.html).
+	fn decode_len<KeyArg: Borrow<K>>(key: KeyArg) -> Result<usize, &'static str>
+		where V: codec::DecodeLength, V: Len;
+}
+
+impl <K: Codec, V: Codec, U> DecodeLengthStorageMap<K, V> for U
+	where U: hashed::generator::DecodeLengthStorageMap<K, V>
+{
+	fn decode_len<KeyArg: Borrow<K>>(key: KeyArg) -> Result<usize, &'static str>
+		where V: codec::DecodeLength, V: Len
+	{
+		U::decode_len(key.borrow(), &mut RuntimeStorage)
+	}
 }
 
 /// A storage map that can be enumerated.
diff --git a/srml/support/src/storage/storage_items.rs b/srml/support/src/storage/storage_items.rs
index 06cb8fc55b5cd..a2a5c3229fa00 100644
--- a/srml/support/src/storage/storage_items.rs
+++ b/srml/support/src/storage/storage_items.rs
@@ -172,6 +172,7 @@ macro_rules! __storage_items_internal {
 
 		impl $crate::storage::hashed::generator::StorageValue<$ty> for $name {
 			type Query = $gettype;
+			type Default = ();
 
 			/// Get the storage key.
 			fn key() -> &'static [u8] {
@@ -221,8 +222,8 @@ macro_rules! __storage_items_internal {
 
 		impl $crate::storage::hashed::generator::StorageMap<$kty, $ty> for $name {
 			type Query = $gettype;
-
 			type Hasher = $crate::Blake2_256;
+			type Default = ();
 
 			/// Get the prefix key in storage.
 			fn prefix() -> &'static [u8] {
@@ -795,18 +796,41 @@ mod test3 {
 
 #[cfg(test)]
 #[allow(dead_code)]
-mod test_map_vec_append {
+mod test_append_and_len {
+	use crate::storage::{AppendableStorageMap, DecodeLengthStorageMap, StorageMap, StorageValue};
+	use runtime_io::{with_externalities, TestExternalities};
+	use codec::{Encode, Decode};
+
 	pub trait Trait {
 		type Origin;
 		type BlockNumber;
 	}
+
 	decl_module! {
 		pub struct Module<T: Trait> for enum Call where origin: T::Origin {}
 	}
+
+	#[derive(PartialEq, Eq, Clone, Encode, Decode)]
+	struct NoDef(u32);
+
 	crate::decl_storage! {
 		trait Store for Module<T: Trait> as Test {
+			NoDefault: Option<NoDef>;
+
 			JustVec: Vec<u32>;
+			JustVecWithDefault: Vec<u32> = vec![6, 9];
+			OptionVec: Option<Vec<u32>>;
+			OptionVecWithDefault: Option<Vec<u32>> = Some(vec![6, 9]);
+
 			MapVec: map u32 => Vec<u32>;
+			MapVecWithDefault: map u32 => Vec<u32> = vec![6, 9];
+			OptionMapVec: map u32 => Option<Vec<u32>>;
+			OptionMapVecWithDefault: map u32 => Option<Vec<u32>> = Some(vec![6, 9]);
+
+			LinkedMapVec: linked_map u32 => Vec<u32>;
+			LinkedMapVecWithDefault: linked_map u32 => Vec<u32> = vec![6, 9];
+			OptionLinkedMapVec: linked_map u32 => Option<Vec<u32>>;
+			OptionLinkedMapVecWithDefault: linked_map u32 => Option<Vec<u32>> = Some(vec![6, 9]);
 		}
 	}
 
@@ -817,21 +841,116 @@ mod test_map_vec_append {
 		type BlockNumber = u32;
 	}
 
+	#[test]
+	fn default_for_option() {
+		with_externalities(&mut TestExternalities::default(), || {
+			assert_eq!(OptionVecWithDefault::get(), Some(vec![6, 9]));
+			assert_eq!(OptionVec::get(), None);
+			assert_eq!(JustVec::get(), vec![]);
+		});
+	}
+
 	#[test]
 	fn append_works() {
-		use crate::storage::{AppendableStorageMap, StorageMap, StorageValue};
-		use runtime_io::{with_externalities, TestExternalities};
+		with_externalities(&mut TestExternalities::default(), || {
+			let _ = MapVec::append(1, [1, 2, 3].iter());
+			let _ = MapVec::append(1, [4, 5].iter());
+			assert_eq!(MapVec::get(1), vec![1, 2, 3, 4, 5]);
+
+			let _ = JustVec::append([1, 2, 3].iter());
+			let _ = JustVec::append([4, 5].iter());
+			assert_eq!(JustVec::get(), vec![1, 2, 3, 4, 5]);
+		});
+	}
+
+	#[test]
+	fn append_works_for_default() {
+		with_externalities(&mut TestExternalities::default(), || {
+			assert_eq!(JustVecWithDefault::get(), vec![6, 9]);
+			let _ = JustVecWithDefault::append([1].iter());
+			assert_eq!(JustVecWithDefault::get(), vec![6, 9, 1]);
+
+			assert_eq!(MapVecWithDefault::get(0), vec![6, 9]);
+			let _ = MapVecWithDefault::append(0, [1].iter());
+			assert_eq!(MapVecWithDefault::get(0), vec![6, 9, 1]);
+
+			assert_eq!(OptionVec::get(), None);
+			let _ = OptionVec::append([1].iter());
+			assert_eq!(OptionVec::get(), Some(vec![1]));
+		});
+	}
 
+	#[test]
+	fn append_or_put_works() {
 		with_externalities(&mut TestExternalities::default(), || {
-			let _ = MapVec::append(1, &[1, 2, 3]);
-			let _ = MapVec::append(1, &[4, 5]);
+			let _ = MapVec::append_or_insert(1, [1, 2, 3].iter());
+			let _ = MapVec::append_or_insert(1, [4, 5].iter());
 			assert_eq!(MapVec::get(1), vec![1, 2, 3, 4, 5]);
 
-			let _ = JustVec::append(&[1, 2, 3]);
-			let _ = JustVec::append(&[4, 5]);
+			let _ = JustVec::append_or_put([1, 2, 3].iter());
+			let _ = JustVec::append_or_put([4, 5].iter());
 			assert_eq!(JustVec::get(), vec![1, 2, 3, 4, 5]);
 		});
 	}
+
+	#[test]
+	fn len_works() {
+		with_externalities(&mut TestExternalities::default(), || {
+			JustVec::put(&vec![1, 2, 3, 4]);
+			OptionVec::put(&vec![1, 2, 3, 4, 5]);
+			MapVec::insert(1, &vec![1, 2, 3, 4, 5, 6]);
+			LinkedMapVec::insert(2, &vec![1, 2, 3]);
+
+			assert_eq!(JustVec::decode_len().unwrap(), 4);
+			assert_eq!(OptionVec::decode_len().unwrap(), 5);
+			assert_eq!(MapVec::decode_len(1).unwrap(), 6);
+			assert_eq!(LinkedMapVec::decode_len(2).unwrap(), 3);
+		});
+	}
+
+	#[test]
+	fn len_works_for_default() {
+		with_externalities(&mut TestExternalities::default(), || {
+			// vec
+			assert_eq!(JustVec::get(), vec![]);
+			assert_eq!(JustVec::decode_len(), Ok(0));
+
+			assert_eq!(JustVecWithDefault::get(), vec![6, 9]);
+			assert_eq!(JustVecWithDefault::decode_len(), Ok(2));
+
+			assert_eq!(OptionVec::get(), None);
+			assert_eq!(OptionVec::decode_len(), Ok(0));
+
+			assert_eq!(OptionVecWithDefault::get(), Some(vec![6, 9]));
+			assert_eq!(OptionVecWithDefault::decode_len(), Ok(2));
+
+			// map
+			assert_eq!(MapVec::get(0), vec![]);
+			assert_eq!(MapVec::decode_len(0), Ok(0));
+
+			assert_eq!(MapVecWithDefault::get(0), vec![6, 9]);
+			assert_eq!(MapVecWithDefault::decode_len(0), Ok(2));
+
+			assert_eq!(OptionMapVec::get(0), None);
+			assert_eq!(OptionMapVec::decode_len(0), Ok(0));
+
+			assert_eq!(OptionMapVecWithDefault::get(0), Some(vec![6, 9]));
+			assert_eq!(OptionMapVecWithDefault::decode_len(0), Ok(2));
+
+			// linked map
+			assert_eq!(LinkedMapVec::get(0), vec![]);
+			assert_eq!(LinkedMapVec::decode_len(0), Ok(0));
+
+			assert_eq!(LinkedMapVecWithDefault::get(0), vec![6, 9]);
+			assert_eq!(LinkedMapVecWithDefault::decode_len(0), Ok(2));
+
+			assert_eq!(OptionLinkedMapVec::get(0), None);
+			assert_eq!(OptionLinkedMapVec::decode_len(0), Ok(0));
+
+			assert_eq!(OptionLinkedMapVecWithDefault::get(0), Some(vec![6, 9]));
+			assert_eq!(OptionLinkedMapVecWithDefault::decode_len(0), Ok(2));
+		});
+	}
 }
 
 
diff --git a/srml/support/src/traits.rs b/srml/support/src/traits.rs
index cca9fd2b10376..a5e52f5f66c4f 100644
--- a/srml/support/src/traits.rs
+++ b/srml/support/src/traits.rs
@@ -26,6 +26,28 @@ use crate::sr_primitives::ConsensusEngineId;
 
 use super::for_each_tuple;
 
+/// A trait that can return the default value of a storage item. This must only ever be implemented
+/// for a special delegator struct for each storage item
+pub trait StorageDefault<V>: Sized {
+	/// Return the default value of type `V`. `None`, if `V` does not have a proper default value.
+	fn default() -> Option<V>;
+}
+
+// FIXME #1466 This is needed for `storage_items!`. Should be removed once it is deprecated.
+impl<T: Default> StorageDefault<T> for () { fn default() -> Option<T> { Some(Default::default()) } }
+
+/// Anything that can have a `::len()` method.
+pub trait Len {
+	/// Return the length of data type.
+	fn len(&self) -> usize;
+}
+
+impl<T: IntoIterator + Clone,> Len for T where <T as IntoIterator>::IntoIter: ExactSizeIterator {
+	fn len(&self) -> usize {
+		self.clone().into_iter().len()
+	}
+}
+
 /// A trait for querying a single fixed value from a type.
 pub trait Get<T> {
 	/// Return a constant value.
@@ -620,7 +642,7 @@ bitmask! {
 }
 
 pub trait Time {
-	type Moment: SimpleArithmetic + Codec + Clone + Default;
+	type Moment: SimpleArithmetic + Codec + Clone + Default + Copy;
 
 	fn now() -> Self::Moment;
 }
diff --git a/srml/system/src/lib.rs b/srml/system/src/lib.rs
index 56093f4f7ec8e..2343af8bec125 100644
--- a/srml/system/src/lib.rs
+++ b/srml/system/src/lib.rs
@@ -42,6 +42,23 @@
 //!
 //! See the [`Module`](./struct.Module.html) struct for details of publicly available functions.
 //!
+//! ### Signed Extensions
+//!
+//! The system module defines the following extensions:
+//!
+//!   - [`CheckWeight`]: Checks the weight and length of the block and ensure that it does not
+//!     exceed the limits.
+//!   - ['CheckNonce']: Checks the nonce of the transaction. Contains a single payload of type
+//!     `T::Index`.
+//!   - [`CheckEra`]: Checks the era of the transaction. Contains a single payload of type `Era`.
+//!   - [`CheckGenesis`]: Checks the provided genesis hash of the transaction. Must be a part of the
+//!     signed payload of the transaction.
+//!   - [`CheckVersion`]: Checks that the runtime version is the same as the one encoded in the
+//!     transaction.
+//!
+//! Lookup the runtime aggregator file (e.g. `node/runtime`) to see the full list of signed
+//! extensions included in a chain.
+//!
 //! ## Usage
 //!
 //! ### Prerequisites
@@ -561,7 +578,7 @@ impl<T: Trait> Module<T> {
 		// We perform early return if we've reached the maximum capacity of the event list,
 		// so `Events<T>` seems to be corrupted. Also, this has happened after the start of execution
 		// (since the event list is cleared at the block initialization).
-		if <Events<T>>::append(&[event]).is_err() {
+		if <Events<T>>::append([event].into_iter()).is_err() {
 			// The most sensible thing to do here is to just ignore this event and wait until the
 			// new block.
 			return;
diff --git a/srml/timestamp/src/lib.rs b/srml/timestamp/src/lib.rs
index 78a741aff48a5..1b03b5b9af79f 100644
--- a/srml/timestamp/src/lib.rs
+++ b/srml/timestamp/src/lib.rs
@@ -195,9 +195,9 @@ macro_rules! impl_timestamp_set {
 	);
 
 	( $($t:ident)* ) => {
-		impl<Moment: Clone, $($t: OnTimestampSet<Moment>),*> OnTimestampSet<Moment> for ($($t,)*) {
+		impl<Moment: Copy, $($t: OnTimestampSet<Moment>),*> OnTimestampSet<Moment> for ($($t,)*) {
 			fn on_timestamp_set(moment: Moment) {
-				$($t::on_timestamp_set(moment.clone());)*
+				$($t::on_timestamp_set(moment);)*
 			}
 		}
 	}
@@ -209,7 +209,7 @@ for_each_tuple!(impl_timestamp_set);
 pub trait Trait: system::Trait {
 	/// Type used for expressing timestamp.
 	type Moment: Parameter + Default + SimpleArithmetic
-		+ Scale<Self::BlockNumber, Output = Self::Moment>;
+		+ Scale<Self::BlockNumber, Output = Self::Moment> + Copy;
 
 	/// Something which can be notified when the timestamp is set. Set this to `()` if not needed.
 	type OnTimestampSet: OnTimestampSet<Self::Moment>;
@@ -246,7 +246,7 @@ decl_module! {
 				Self::now().is_zero() || now >= Self::now() + T::MinimumPeriod::get(),
 				"Timestamp must increment by at least <MinimumPeriod> between sequential blocks"
 			);
-			<Self as Store>::Now::put(now.clone());
+			<Self as Store>::Now::put(now);
 			<Self as Store>::DidUpdate::put(true);
 
 			<T::OnTimestampSet as OnTimestampSet<_>>::on_timestamp_set(now);
diff --git a/srml/treasury/src/lib.rs b/srml/treasury/src/lib.rs
index 12ef4fc14e2b1..1e709b74a613b 100644
--- a/srml/treasury/src/lib.rs
+++ b/srml/treasury/src/lib.rs
@@ -89,11 +89,6 @@ type NegativeImbalanceOf<T> = <<T as Trait>::Currency as Currency<<T as system::
 
 const MODULE_ID: ModuleId = ModuleId(*b"py/trsry");
 
-pub const DEFAULT_PROPOSAL_BOND: u32 = 0;
-pub const DEFAULT_PROPOSAL_BOND_MINIMUM: u32 = 0;
-pub const DEFAULT_SPEND_PERIOD: u32 = 0;
-pub const DEFAULT_BURN: u32 = 0;
-
 pub trait Trait: system::Trait {
 	/// The staking balance.
 	type Currency: Currency<Self::AccountId> + ReservableCurrency<Self::AccountId>;
diff --git a/test-utils/transaction-factory/src/complex_mode.rs b/test-utils/transaction-factory/src/complex_mode.rs
index 85b12248d80ba..ed76a66b09083 100644
--- a/test-utils/transaction-factory/src/complex_mode.rs
+++ b/test-utils/transaction-factory/src/complex_mode.rs
@@ -41,29 +41,30 @@
 use std::sync::Arc;
 
 use log::info;
+use client::Client;
 use client::block_builder::api::BlockBuilder;
 use client::runtime_api::ConstructRuntimeApi;
+use primitives::{Blake2Hasher, Hasher};
 use sr_primitives::generic::BlockId;
 use sr_primitives::traits::{Block as BlockT, ProvideRuntimeApi, One, Zero};
-use substrate_service::{
-	FactoryBlock, FullClient, ServiceFactory, ComponentClient, FullComponents
-};
 
 use crate::{RuntimeAdapter, create_block};
 
-pub fn next<F, RA>(
+pub fn next<RA, Backend, Exec, Block, RtApi>(
 	factory_state: &mut RA,
-	client: &Arc<ComponentClient<FullComponents<F>>>,
+	client: &Arc<Client<Backend, Exec, Block, RtApi>>,
 	version: u32,
 	genesis_hash: <RA::Block as BlockT>::Hash,
 	prior_block_hash: <RA::Block as BlockT>::Hash,
-	prior_block_id: BlockId<F::Block>,
-) -> Option<<F as ServiceFactory>::Block>
+	prior_block_id: BlockId<Block>,
+) -> Option<Block>
 where
-	F: ServiceFactory,
-	F::RuntimeApi: ConstructRuntimeApi<FactoryBlock<F>, FullClient<F>>,
-	FullClient<F>: ProvideRuntimeApi,
-	<FullClient<F> as ProvideRuntimeApi>::Api: BlockBuilder<FactoryBlock<F>>,
+	Block: BlockT<Hash = <Blake2Hasher as Hasher>::Out>,
+	Exec: client::CallExecutor<Block, Blake2Hasher> + Send + Sync + Clone,
+	Backend: client::backend::Backend<Block, Blake2Hasher> + Send,
+	Client<Backend, Exec, Block, RtApi>: ProvideRuntimeApi,
+	<Client<Backend, Exec, Block, RtApi> as ProvideRuntimeApi>::Api: BlockBuilder<Block>,
+	RtApi: ConstructRuntimeApi<Block, Client<Backend, Exec, Block, RtApi>> + Send + Sync,
 	RA: RuntimeAdapter,
 {
 	let total = factory_state.start_number() + factory_state.num() * factory_state.rounds();
@@ -102,7 +103,7 @@ where
 	let inherents = client.runtime_api().inherent_extrinsics(&prior_block_id, inherents)
 		.expect("Failed to create inherent extrinsics");
 
-	let block = create_block::<F, RA>(&client, transfer, inherents);
+	let block = create_block::<RA, _, _, _, _>(&client, transfer, inherents);
 	info!(
 		"Created block {} with hash {}. Transferring {} from {} to {}.",
 		factory_state.block_no() + RA::Number::one(),
diff --git a/test-utils/transaction-factory/src/lib.rs b/test-utils/transaction-factory/src/lib.rs
index 16bb08a2b436d..5d63f906a73cf 100644
--- a/test-utils/transaction-factory/src/lib.rs
+++ b/test-utils/transaction-factory/src/lib.rs
@@ -26,22 +26,19 @@ use std::fmt::Display;
 
 use log::info;
 
-use client::block_builder::api::BlockBuilder;
-use client::runtime_api::ConstructRuntimeApi;
+use client::{Client, block_builder::api::BlockBuilder, runtime_api::ConstructRuntimeApi};
 use consensus_common::{
 	BlockOrigin, BlockImportParams, InherentData, ForkChoiceStrategy,
 	SelectChain
 };
 use consensus_common::block_import::BlockImport;
 use codec::{Decode, Encode};
+use primitives::{Blake2Hasher, Hasher};
 use sr_primitives::generic::BlockId;
 use sr_primitives::traits::{
 	Block as BlockT, Header as HeaderT, ProvideRuntimeApi, SimpleArithmetic,
 	One, Zero,
 };
-use substrate_service::{
-	FactoryBlock, FactoryFullConfiguration, FullClient, new_client,
-	ServiceFactory, ComponentClient, FullComponents};
 pub use crate::modes::Mode;
 
 pub mod modes;
@@ -95,15 +92,19 @@ pub trait RuntimeAdapter {
 
 /// Manufactures transactions. The exact amount depends on
 /// `mode`, `num` and `rounds`.
-pub fn factory<F, RA>(
+pub fn factory<RA, Backend, Exec, Block, RtApi, Sc>(
 	mut factory_state: RA,
-	mut config: FactoryFullConfiguration<F>,
+	client: &Arc<Client<Backend, Exec, Block, RtApi>>,
+	select_chain: &Sc,
 ) -> cli::error::Result<()>
 where
-	F: ServiceFactory,
-	F::RuntimeApi: ConstructRuntimeApi<FactoryBlock<F>, FullClient<F>>,
-	FullClient<F>: ProvideRuntimeApi,
-	<FullClient<F> as ProvideRuntimeApi>::Api: BlockBuilder<FactoryBlock<F>>,
+	Block: BlockT<Hash = <Blake2Hasher as Hasher>::Out>,
+	Exec: client::CallExecutor<Block, Blake2Hasher> + Send + Sync + Clone,
+	Backend: client::backend::Backend<Block, Blake2Hasher> + Send,
+	Client<Backend, Exec, Block, RtApi>: ProvideRuntimeApi,
+	<Client<Backend, Exec, Block, RtApi> as ProvideRuntimeApi>::Api: BlockBuilder<Block>,
+	RtApi: ConstructRuntimeApi<Block, Client<Backend, Exec, Block, RtApi>> + Send + Sync,
+	Sc: SelectChain<Block>,
 	RA: RuntimeAdapter,
 	<<RA as RuntimeAdapter>::Block as BlockT>::Hash: From<primitives::H256>,
 {
@@ -112,20 +113,16 @@ where
 		return Err(cli::error::Error::Input(msg));
 	}
 
-	let client = new_client::<F>(&config)?;
-
-	let select_chain = F::build_select_chain(&mut config, client.clone())?;
-
-	let best_header: Result<<F::Block as BlockT>::Header, cli::error::Error> =
+	let best_header: Result<<Block as BlockT>::Header, cli::error::Error> =
 		select_chain.best_chain().map_err(|e| format!("{:?}", e).into());
 	let mut best_hash = best_header?.hash();
-	let best_block_id = BlockId::<F::Block>::hash(best_hash);
+	let best_block_id = BlockId::<Block>::hash(best_hash);
 	let version = client.runtime_version_at(&best_block_id)?.spec_version;
 	let genesis_hash = client.block_hash(Zero::zero())?
 		.expect("Genesis block always exists; qed").into();
 
 	while let Some(block) = match factory_state.mode() {
-		Mode::MasterToNToM => complex_mode::next::<F, RA>(
+		Mode::MasterToNToM => complex_mode::next::<RA, _, _, _, _>(
 			&mut factory_state,
 			&client,
 			version,
@@ -133,7 +130,7 @@ where
 			best_hash.into(),
 			best_block_id,
 		),
-		_ => simple_modes::next::<F, RA>(
+		_ => simple_modes::next::<RA, _, _, _, _>(
 			&mut factory_state,
 			&client,
 			version,
@@ -143,7 +140,7 @@ where
 		),
 	} {
 		best_hash = block.header().hash();
-		import_block::<F>(&client, block);
+		import_block(&client, block);
 
 		info!("Imported block at {}", factory_state.block_no());
 	}
@@ -152,16 +149,18 @@ where
 }
 
 /// Create a baked block from a transfer extrinsic and timestamp inherent.
-pub fn create_block<F, RA>(
-	client: &Arc<ComponentClient<FullComponents<F>>>,
+pub fn create_block<RA, Backend, Exec, Block, RtApi>(
+	client: &Arc<Client<Backend, Exec, Block, RtApi>>,
 	transfer: <RA::Block as BlockT>::Extrinsic,
-	inherent_extrinsics: Vec<<F::Block as BlockT>::Extrinsic>,
-) -> <F as ServiceFactory>::Block
+	inherent_extrinsics: Vec<<Block as BlockT>::Extrinsic>,
+) -> Block
 where
-	F: ServiceFactory,
-	FullClient<F>: ProvideRuntimeApi,
-	F::RuntimeApi: ConstructRuntimeApi<FactoryBlock<F>, FullClient<F>>,
-	<FullClient<F> as ProvideRuntimeApi>::Api: BlockBuilder<FactoryBlock<F>>,
+	Block: BlockT<Hash = <Blake2Hasher as Hasher>::Out>,
+	Exec: client::CallExecutor<Block, Blake2Hasher> + Send + Sync + Clone,
+	Backend: client::backend::Backend<Block, Blake2Hasher> + Send,
+	Client<Backend, Exec, Block, RtApi>: ProvideRuntimeApi,
+	RtApi: ConstructRuntimeApi<Block, Client<Backend, Exec, Block, RtApi>> + Send + Sync,
+	<Client<Backend, Exec, Block, RtApi> as ProvideRuntimeApi>::Api: BlockBuilder<Block>,
 	RA: RuntimeAdapter,
 {
 	let mut block = client.new_block(Default::default()).expect("Failed to create new block");
@@ -177,10 +176,13 @@ where
 	block.bake().expect("Failed to bake block")
 }
 
-fn import_block<F>(
-	client: &Arc<ComponentClient<FullComponents<F>>>,
-	block: <F as ServiceFactory>::Block
-) -> () where F: ServiceFactory
+fn import_block<Backend, Exec, Block, RtApi>(
+	client: &Arc<Client<Backend, Exec, Block, RtApi>>,
+	block: Block
+) -> () where 
+	Block: BlockT<Hash = <Blake2Hasher as Hasher>::Out>,
+	Exec: client::CallExecutor<Block, Blake2Hasher> + Send + Sync + Clone,
+	Backend: client::backend::Backend<Block, Blake2Hasher> + Send,
 {
 	let import = BlockImportParams {
 		origin: BlockOrigin::File,
diff --git a/test-utils/transaction-factory/src/simple_modes.rs b/test-utils/transaction-factory/src/simple_modes.rs
index ec4f484fa9827..bcbb91200657f 100644
--- a/test-utils/transaction-factory/src/simple_modes.rs
+++ b/test-utils/transaction-factory/src/simple_modes.rs
@@ -36,29 +36,30 @@
 use std::sync::Arc;
 
 use log::info;
+use client::Client;
 use client::block_builder::api::BlockBuilder;
 use client::runtime_api::ConstructRuntimeApi;
+use primitives::{Blake2Hasher, Hasher};
 use sr_primitives::traits::{Block as BlockT, ProvideRuntimeApi, One};
 use sr_primitives::generic::BlockId;
-use substrate_service::{
-	FactoryBlock, FullClient, ServiceFactory, ComponentClient, FullComponents
-};
 
 use crate::{Mode, RuntimeAdapter, create_block};
 
-pub fn next<F, RA>(
+pub fn next<RA, Backend, Exec, Block, RtApi>(
 	factory_state: &mut RA,
-	client: &Arc<ComponentClient<FullComponents<F>>>,
+	client: &Arc<Client<Backend, Exec, Block, RtApi>>,
 	version: u32,
 	genesis_hash: <RA::Block as BlockT>::Hash,
 	prior_block_hash: <RA::Block as BlockT>::Hash,
-	prior_block_id: BlockId<F::Block>,
-) -> Option<<F as ServiceFactory>::Block>
+	prior_block_id: BlockId<Block>,
+) -> Option<Block>
 where
-	F: ServiceFactory,
-	F::RuntimeApi: ConstructRuntimeApi<FactoryBlock<F>, FullClient<F>>,
-	FullClient<F>: ProvideRuntimeApi,
-	<FullClient<F> as ProvideRuntimeApi>::Api: BlockBuilder<FactoryBlock<F>>,
+	Block: BlockT<Hash = <Blake2Hasher as Hasher>::Out>,
+	Exec: client::CallExecutor<Block, Blake2Hasher> + Send + Sync + Clone,
+	Backend: client::backend::Backend<Block, Blake2Hasher> + Send,
+	Client<Backend, Exec, Block, RtApi>: ProvideRuntimeApi,
+	<Client<Backend, Exec, Block, RtApi> as ProvideRuntimeApi>::Api: BlockBuilder<Block>,
+	RtApi: ConstructRuntimeApi<Block, Client<Backend, Exec, Block, RtApi>> + Send + Sync,
 	RA: RuntimeAdapter,
 {
 	if factory_state.block_no() >= factory_state.num() {
@@ -93,7 +94,7 @@ where
 	let inherents = client.runtime_api().inherent_extrinsics(&prior_block_id, inherents)
 		.expect("Failed to create inherent extrinsics");
 
-	let block = create_block::<F, RA>(&client, transfer, inherents);
+	let block = create_block::<RA, _, _, _, _>(&client, transfer, inherents);
 
 	factory_state.set_block_no(factory_state.block_no() + RA::Number::one());