diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5a65fff7c..fc04c6676 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,9 @@
 
 ## [Unreleased]
 
+
+## [4.0.0] - 2022-05-25
+
 ### Added
 - Added `Eq`, `PartialOrd`, `Ord` to `json_types` integer types. [PR 823](https://github.com/near/near-sdk-rs/pull/823)
 
@@ -12,6 +15,12 @@
   - `receipt_indices` field removed from `Receipt` type in testing utils
 - Deprecate and remove `near-sdk-sim`. Removes `sim` proxy struct from `#[near_bindgen]`. [PR 817](https://github.com/near/near-sdk-rs/pull/817)
   - If `near-sdk-sim` tests can't be migrated to [workspaces-rs](https://github.com/near/workspaces-rs), `4.0.0-pre.9` version of `near-sdk-rs` and `near-sdk-sim` should be used
+- Optimized read_register to read to non-zeroed buffer. [PR 804](https://github.com/near/near-sdk-rs/pull/804)
+- Switched Rust edition for libraries to `2021`. [PR 669](https://github.com/near/near-sdk-rs/pull/669)
+
+### Fixes
+- Avoid loading result bytes with `near_sdk::is_promise_success()`. [PR 816](https://github.com/near/near-sdk-rs/pull/816)
+
 
 ## [4.0.0-pre.9] - 2022-05-12
 
@@ -282,8 +291,9 @@ impl StatusMessage {
 * In fungible token remove account from storage if its balance is 0 https://github.com/near/near-sdk-rs/pull/179
 
 [Unreleased]: https://github.com/near/near-sdk-rs/compare/4.0.0-pre.9...HEAD
-[4.0.0-pre.9] https://github.com/near/near-sdk-rs/compare/4.0.0-pre.8...4.0.0-pre.9
-[4.0.0-pre.8] https://github.com/near/near-sdk-rs/compare/4.0.0-pre.7...4.0.0-pre.8
+[4.0.0]: https://github.com/near/near-sdk-rs/compare/4.0.0-pre.9...4.0.0
+[4.0.0-pre.9]: https://github.com/near/near-sdk-rs/compare/4.0.0-pre.8...4.0.0-pre.9
+[4.0.0-pre.8]: https://github.com/near/near-sdk-rs/compare/4.0.0-pre.7...4.0.0-pre.8
 [4.0.0-pre.7]: https://github.com/near/near-sdk-rs/compare/4.0.0-pre.6...4.0.0-pre.7
 [4.0.0-pre.6]: https://github.com/near/near-sdk-rs/compare/4.0.0-pre.5...4.0.0-pre.6
 [4.0.0-pre.5]: https://github.com/near/near-sdk-rs/compare/4.0.0-pre.4...4.0.0-pre.5
diff --git a/examples/callback-results/Cargo.lock b/examples/callback-results/Cargo.lock
index 3d4b835ed..55fa9f80e 100644
--- a/examples/callback-results/Cargo.lock
+++ b/examples/callback-results/Cargo.lock
@@ -1615,7 +1615,7 @@ dependencies = [
 
 [[package]]
 name = "near-sdk"
-version = "4.0.0-pre.9"
+version = "4.0.0"
 dependencies = [
  "base64 0.13.0",
  "borsh",
@@ -1633,7 +1633,7 @@ dependencies = [
 
 [[package]]
 name = "near-sdk-macros"
-version = "4.0.0-pre.9"
+version = "4.0.0"
 dependencies = [
  "Inflector",
  "proc-macro2",
diff --git a/examples/callback-results/res/callback_results.wasm b/examples/callback-results/res/callback_results.wasm
index 2a4a991a1..86a9934d0 100755
Binary files a/examples/callback-results/res/callback_results.wasm and b/examples/callback-results/res/callback_results.wasm differ
diff --git a/examples/cross-contract-calls/Cargo.lock b/examples/cross-contract-calls/Cargo.lock
index 1224b783c..80202372b 100644
--- a/examples/cross-contract-calls/Cargo.lock
+++ b/examples/cross-contract-calls/Cargo.lock
@@ -1666,7 +1666,7 @@ dependencies = [
 
 [[package]]
 name = "near-sdk"
-version = "4.0.0-pre.9"
+version = "4.0.0"
 dependencies = [
  "base64 0.13.0",
  "borsh",
@@ -1684,7 +1684,7 @@ dependencies = [
 
 [[package]]
 name = "near-sdk-macros"
-version = "4.0.0-pre.9"
+version = "4.0.0"
 dependencies = [
  "Inflector",
  "proc-macro2",
diff --git a/examples/cross-contract-calls/res/cross_contract_high_level.wasm b/examples/cross-contract-calls/res/cross_contract_high_level.wasm
index aa9113adf..5cc50327f 100755
Binary files a/examples/cross-contract-calls/res/cross_contract_high_level.wasm and b/examples/cross-contract-calls/res/cross_contract_high_level.wasm differ
diff --git a/examples/cross-contract-calls/res/cross_contract_low_level.wasm b/examples/cross-contract-calls/res/cross_contract_low_level.wasm
index 0137db3fd..49b37c4be 100755
Binary files a/examples/cross-contract-calls/res/cross_contract_low_level.wasm and b/examples/cross-contract-calls/res/cross_contract_low_level.wasm differ
diff --git a/examples/factory-contract/Cargo.lock b/examples/factory-contract/Cargo.lock
index b53cc1fc1..eaecc6bde 100644
--- a/examples/factory-contract/Cargo.lock
+++ b/examples/factory-contract/Cargo.lock
@@ -1666,7 +1666,7 @@ dependencies = [
 
 [[package]]
 name = "near-sdk"
-version = "4.0.0-pre.9"
+version = "4.0.0"
 dependencies = [
  "base64 0.13.0",
  "borsh",
@@ -1684,7 +1684,7 @@ dependencies = [
 
 [[package]]
 name = "near-sdk-macros"
-version = "4.0.0-pre.9"
+version = "4.0.0"
 dependencies = [
  "Inflector",
  "proc-macro2",
diff --git a/examples/factory-contract/res/factory_contract_high_level.wasm b/examples/factory-contract/res/factory_contract_high_level.wasm
index 17e1e95a2..04ca0f045 100755
Binary files a/examples/factory-contract/res/factory_contract_high_level.wasm and b/examples/factory-contract/res/factory_contract_high_level.wasm differ
diff --git a/examples/factory-contract/res/factory_contract_low_level.wasm b/examples/factory-contract/res/factory_contract_low_level.wasm
index 4a5c43ce7..cf233a40c 100755
Binary files a/examples/factory-contract/res/factory_contract_low_level.wasm and b/examples/factory-contract/res/factory_contract_low_level.wasm differ
diff --git a/examples/fungible-token/Cargo.lock b/examples/fungible-token/Cargo.lock
index 4b4c99024..e769990fe 100644
--- a/examples/fungible-token/Cargo.lock
+++ b/examples/fungible-token/Cargo.lock
@@ -1390,7 +1390,7 @@ dependencies = [
 
 [[package]]
 name = "near-contract-standards"
-version = "4.0.0-pre.9"
+version = "4.0.0"
 dependencies = [
  "near-sdk",
  "serde",
@@ -1772,7 +1772,7 @@ dependencies = [
 
 [[package]]
 name = "near-sdk"
-version = "4.0.0-pre.9"
+version = "4.0.0"
 dependencies = [
  "base64 0.13.0",
  "borsh",
@@ -1790,7 +1790,7 @@ dependencies = [
 
 [[package]]
 name = "near-sdk-macros"
-version = "4.0.0-pre.9"
+version = "4.0.0"
 dependencies = [
  "Inflector",
  "proc-macro2",
diff --git a/examples/fungible-token/res/defi.wasm b/examples/fungible-token/res/defi.wasm
index 78edf0250..aefa8c80a 100755
Binary files a/examples/fungible-token/res/defi.wasm and b/examples/fungible-token/res/defi.wasm differ
diff --git a/examples/fungible-token/res/fungible_token.wasm b/examples/fungible-token/res/fungible_token.wasm
index 59ae40f6a..494035f69 100755
Binary files a/examples/fungible-token/res/fungible_token.wasm and b/examples/fungible-token/res/fungible_token.wasm differ
diff --git a/examples/lockable-fungible-token/Cargo.lock b/examples/lockable-fungible-token/Cargo.lock
index 5c3aa749d..60e7ea173 100644
--- a/examples/lockable-fungible-token/Cargo.lock
+++ b/examples/lockable-fungible-token/Cargo.lock
@@ -1745,7 +1745,7 @@ dependencies = [
 
 [[package]]
 name = "near-sdk"
-version = "4.0.0-pre.9"
+version = "4.0.0"
 dependencies = [
  "base64 0.13.0",
  "borsh",
@@ -1763,7 +1763,7 @@ dependencies = [
 
 [[package]]
 name = "near-sdk-macros"
-version = "4.0.0-pre.9"
+version = "4.0.0"
 dependencies = [
  "Inflector",
  "proc-macro2",
diff --git a/examples/lockable-fungible-token/res/lockable_fungible_token.wasm b/examples/lockable-fungible-token/res/lockable_fungible_token.wasm
index 1d7f41265..e1bb81f53 100755
Binary files a/examples/lockable-fungible-token/res/lockable_fungible_token.wasm and b/examples/lockable-fungible-token/res/lockable_fungible_token.wasm differ
diff --git a/examples/mission-control/Cargo.lock b/examples/mission-control/Cargo.lock
index 9251f2884..35b8ffae9 100644
--- a/examples/mission-control/Cargo.lock
+++ b/examples/mission-control/Cargo.lock
@@ -560,7 +560,7 @@ dependencies = [
 
 [[package]]
 name = "near-sdk"
-version = "4.0.0-pre.9"
+version = "4.0.0"
 dependencies = [
  "base64 0.13.0",
  "borsh",
@@ -578,7 +578,7 @@ dependencies = [
 
 [[package]]
 name = "near-sdk-macros"
-version = "4.0.0-pre.9"
+version = "4.0.0"
 dependencies = [
  "Inflector",
  "proc-macro2",
diff --git a/examples/mission-control/res/mission_control.wasm b/examples/mission-control/res/mission_control.wasm
index d95069835..a0270fa16 100755
Binary files a/examples/mission-control/res/mission_control.wasm and b/examples/mission-control/res/mission_control.wasm differ
diff --git a/examples/non-fungible-token/Cargo.lock b/examples/non-fungible-token/Cargo.lock
index 4a4e05df0..2ff465b69 100644
--- a/examples/non-fungible-token/Cargo.lock
+++ b/examples/non-fungible-token/Cargo.lock
@@ -1367,7 +1367,7 @@ dependencies = [
 
 [[package]]
 name = "near-contract-standards"
-version = "4.0.0-pre.9"
+version = "4.0.0"
 dependencies = [
  "near-sdk",
  "serde",
@@ -1749,7 +1749,7 @@ dependencies = [
 
 [[package]]
 name = "near-sdk"
-version = "4.0.0-pre.9"
+version = "4.0.0"
 dependencies = [
  "base64 0.13.0",
  "borsh",
@@ -1767,7 +1767,7 @@ dependencies = [
 
 [[package]]
 name = "near-sdk-macros"
-version = "4.0.0-pre.9"
+version = "4.0.0"
 dependencies = [
  "Inflector",
  "proc-macro2",
diff --git a/examples/non-fungible-token/res/approval_receiver.wasm b/examples/non-fungible-token/res/approval_receiver.wasm
index 292a6936c..c95115828 100755
Binary files a/examples/non-fungible-token/res/approval_receiver.wasm and b/examples/non-fungible-token/res/approval_receiver.wasm differ
diff --git a/examples/non-fungible-token/res/non_fungible_token.wasm b/examples/non-fungible-token/res/non_fungible_token.wasm
index e8c6ef899..aa1c4d01d 100755
Binary files a/examples/non-fungible-token/res/non_fungible_token.wasm and b/examples/non-fungible-token/res/non_fungible_token.wasm differ
diff --git a/examples/non-fungible-token/res/token_receiver.wasm b/examples/non-fungible-token/res/token_receiver.wasm
index d1eb822c0..6c9bb6b6d 100755
Binary files a/examples/non-fungible-token/res/token_receiver.wasm and b/examples/non-fungible-token/res/token_receiver.wasm differ
diff --git a/examples/status-message-collections/Cargo.lock b/examples/status-message-collections/Cargo.lock
index a978b12ea..bc7d7dbef 100644
--- a/examples/status-message-collections/Cargo.lock
+++ b/examples/status-message-collections/Cargo.lock
@@ -553,7 +553,7 @@ dependencies = [
 
 [[package]]
 name = "near-sdk"
-version = "4.0.0-pre.9"
+version = "4.0.0"
 dependencies = [
  "base64 0.13.0",
  "borsh",
@@ -571,7 +571,7 @@ dependencies = [
 
 [[package]]
 name = "near-sdk-macros"
-version = "4.0.0-pre.9"
+version = "4.0.0"
 dependencies = [
  "Inflector",
  "proc-macro2",
diff --git a/examples/status-message-collections/res/status_message_collections.wasm b/examples/status-message-collections/res/status_message_collections.wasm
index e2de51607..a76c8da31 100755
Binary files a/examples/status-message-collections/res/status_message_collections.wasm and b/examples/status-message-collections/res/status_message_collections.wasm differ
diff --git a/examples/status-message/Cargo.lock b/examples/status-message/Cargo.lock
index 80b125a7c..48ebb2f04 100644
--- a/examples/status-message/Cargo.lock
+++ b/examples/status-message/Cargo.lock
@@ -553,7 +553,7 @@ dependencies = [
 
 [[package]]
 name = "near-sdk"
-version = "4.0.0-pre.9"
+version = "4.0.0"
 dependencies = [
  "base64 0.13.0",
  "borsh",
@@ -571,7 +571,7 @@ dependencies = [
 
 [[package]]
 name = "near-sdk-macros"
-version = "4.0.0-pre.9"
+version = "4.0.0"
 dependencies = [
  "Inflector",
  "proc-macro2",
diff --git a/examples/status-message/res/status_message.wasm b/examples/status-message/res/status_message.wasm
index 97420e68d..ec9da0f0d 100755
Binary files a/examples/status-message/res/status_message.wasm and b/examples/status-message/res/status_message.wasm differ
diff --git a/examples/test-contract/Cargo.lock b/examples/test-contract/Cargo.lock
index 8724f52f2..278d7add1 100644
--- a/examples/test-contract/Cargo.lock
+++ b/examples/test-contract/Cargo.lock
@@ -553,7 +553,7 @@ dependencies = [
 
 [[package]]
 name = "near-sdk"
-version = "4.0.0-pre.9"
+version = "4.0.0"
 dependencies = [
  "base64 0.13.0",
  "borsh",
@@ -571,7 +571,7 @@ dependencies = [
 
 [[package]]
 name = "near-sdk-macros"
-version = "4.0.0-pre.9"
+version = "4.0.0"
 dependencies = [
  "Inflector",
  "proc-macro2",
diff --git a/examples/test-contract/res/test_contract.wasm b/examples/test-contract/res/test_contract.wasm
index f6cd2fbec..9d0669236 100755
Binary files a/examples/test-contract/res/test_contract.wasm and b/examples/test-contract/res/test_contract.wasm differ
diff --git a/examples/versioned/Cargo.lock b/examples/versioned/Cargo.lock
index 8c51dd395..785853a17 100644
--- a/examples/versioned/Cargo.lock
+++ b/examples/versioned/Cargo.lock
@@ -560,7 +560,7 @@ dependencies = [
 
 [[package]]
 name = "near-sdk"
-version = "4.0.0-pre.9"
+version = "4.0.0"
 dependencies = [
  "base64 0.13.0",
  "borsh",
@@ -579,7 +579,7 @@ dependencies = [
 
 [[package]]
 name = "near-sdk-macros"
-version = "4.0.0-pre.9"
+version = "4.0.0"
 dependencies = [
  "Inflector",
  "proc-macro2",
diff --git a/examples/versioned/res/versioned.wasm b/examples/versioned/res/versioned.wasm
index e3c362bdf..d81af9700 100755
Binary files a/examples/versioned/res/versioned.wasm and b/examples/versioned/res/versioned.wasm differ
diff --git a/near-contract-standards/Cargo.toml b/near-contract-standards/Cargo.toml
index b2e8d10b8..c2c68a439 100644
--- a/near-contract-standards/Cargo.toml
+++ b/near-contract-standards/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "near-contract-standards"
-version = "4.0.0-pre.9"
+version = "4.0.0"
 authors = ["Near Inc <hello@near.org>"]
 edition = "2021"
 license = "GPL-3.0"
@@ -13,6 +13,6 @@ NEAR smart contracts standard library.
 """
 
 [dependencies]
-near-sdk = { path = "../near-sdk", version = "=4.0.0-pre.9" }
+near-sdk = { path = "../near-sdk", version = "=4.0.0" }
 serde = "1"
 serde_json = "1"
diff --git a/near-sdk-macros/Cargo.toml b/near-sdk-macros/Cargo.toml
index c160ab4a2..8bccfe61c 100644
--- a/near-sdk-macros/Cargo.toml
+++ b/near-sdk-macros/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "near-sdk-macros"
-version = "4.0.0-pre.9"
+version = "4.0.0"
 authors = ["Near Inc <max@nearprotocol.com>"]
 edition = "2021"
 license = "MIT OR Apache-2.0"
diff --git a/near-sdk/Cargo.toml b/near-sdk/Cargo.toml
index 69a710b79..f5c905750 100644
--- a/near-sdk/Cargo.toml
+++ b/near-sdk/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "near-sdk"
-version = "4.0.0-pre.9"
+version = "4.0.0"
 authors = ["Near Inc <max@nearprotocol.com>"]
 edition = "2021"
 license = "GPL-3.0"
@@ -20,7 +20,7 @@ path = "compilation_tests/all.rs"
 # Provide near_bidgen macros.
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"
-near-sdk-macros = { path = "../near-sdk-macros", version = "=4.0.0-pre.9" }
+near-sdk-macros = { path = "../near-sdk-macros", version = "=4.0.0" }
 near-sys = { path = "../sys", version = "0.2" }
 base64 = "0.13"
 borsh = "0.9"