Spacemesh: A Programmable Cryptocurrency

go-spacemesh

💾⏰💪

Thanks for your interest in this open source project. This repo is the go implementation of the Spacemesh p2p full node software.

Spacemesh is a decentralized blockchain computer using a new race-free consensus protocol that doesn't involve energy-wasteful proof of work.

We aim to create a secure and scalable decentralized computer formed by a large number of desktop PCs at home.

We are designing and coding a modern blockchain platform from the ground up for scale, security and speed based on the learnings of the achievements and mistakes of previous projects in this space.

To learn more about Spacemesh head over to https://spacemesh.io.

To learn more about the Spacemesh protocol watch this video.

Motivation

Spacemesh is designed to create a decentralized blockchain smart contracts computer and a cryptocurrency that is formed by connecting the home PCs of people from around the world into one virtual computer without incurring massive energy waste and mining pools issues that are inherent in other blockchain computers, and provide a provably-secure and incentive-compatible smart contracts execution environment.

Spacemesh is designed to be ASIC-resistant and in a way that doesn’t give an unfair advantage to rich parties who can afford setting up dedicated computers on the network. We achieve this by using a novel consensus protocol and optimize the software to be most effectively be used on home PCs that are also used for interactive apps.

What is this good for?

Provide dapp and app developers with a robust way to add value exchange and other value related features to their apps at scale. Our goal is to create a truly decentralized cryptocurrency that fulfills the original vision behind bitcoin to become a secure trustless store of value as well as a transactional currency with extremely low transaction fees.

Target Users

go-spacemesh is designed to be installed and operated on users' home PCs to form one decentralized computer. It is going to be distributed in the Spacemesh App but people can also build and run it from source code.

Project Status

We are working hard towards our first major milestone - a public permissionless testnet running the Spacemesh consensus protocol.

Contributing

Thank you for considering to contribute to the go-spacemesh open source project!

We welcome contributions large and small and we actively accept contributions.

• go-spacemesh is part of The Spacemesh open source project, and is MIT licensed open source software.

• We welcome collaborators to the Spacemesh core dev team.

• You don’t have to contribute code! Many important types of contributions are important for our project. See: How to Contribute to Open Source?

• To get started, please read our contributions guidelines.

• Browse Good First Issues.

• Get ethereum awards for your contribution by working on one of our gitcoin funded issues.

Diggin' Deeper

Please read the Spacemesh full FAQ.

go-spacemesh Architecture

Getting

git clone [email protected]:spacemeshos/go-spacemesh.git

or fork the project from https://github.com/spacemeshos/go-spacemesh

Since the project uses Go Modules it is best to place the code outside your $GOPATH. Read this for alternatives.

Setting Up Local Dev Environment

Building is supported on OS X, Linux, FreeBSD, and Windows.

Install Go 1.21 or later for your platform, if you haven't already.

On Windows you need to install make via msys2, MingGW-w64 or mingw.

Ensure that $GOPATH is set correctly and that the $GOPATH/bin directory appears in $PATH.

Before building we need to set up the golang environment. Do this by running:

make install

How to run standalone node?

After you got a binary standalone fully functional network can be launched with a simple command:

./build/go-spacemesh --preset=standalone --genesis-time=2023-06-08T5:30:00.000Z

Network will use short epochs (1 minute), and 10 layers within the epoch (each 6s). Poet is launched in the same process in this mode. So expect that it will periodically hog 1 core. Minimal smeshing is enabled in order for consensus to work.

Public GRPC API are launched on 0.0.0.0:9092. Private - 0.0.0.0:9093.

Building

To build go-spacemesh for your current system architecture, from the project root directory, use:

make build

(On FreeBSD, you should instead use gmake build. You can install gmake with pkg install gmake if it isn't already installed.)

This will build the go-spacemesh binary, saving it in the build/ directory.

On linux or mac you can build a binary for windows using:

make windows

Be aware that this will require a cross-platform gcc like x86_64-w64-mingw32-gcc. Platform-specific binaries are saved to the build/*target* directory.

Using go build and go test without make

To build or test code without using make some golang environment variables must be set appropriately.

The environment variables can be printed by running either make print-env or make print-test-env.

They can be set in 3 ways:

Note: we need to use eval to interpret the commands since there are spaces in the values of the variables so the shell can't correctly split them as arguments.

1. Setting the variables on the same line as the go command (e.g., eval $(make print-env) go build ./...). This affects the environment for that command invocation only.
2. Exporting the variables in the shell's environment (e.g., eval export $(make print-env)). The variables will persist for the duration of that shell (and will be passed to subshells).
3. Setting the variables in the go environment (e.g., eval go env -w $(make print-env)). Persistently adds these values to Go's environment for any future runs.

---

Running

Note: go-spacemesh relies on a gpu setup dynamic library in order to run. make install puts this file in the build folder, so if you are running spacemesh from the build folder you don't need to take any extra action. However if you have built the binary using go build or moved the binary from the build folder you need to ensure that you have the gpu setup dynamic library (the exact name will vary based on your OS) accessible by the go-spacemesh binary. The simplest way to do this is just copy the library file to be in the same directory as the go-spacemesh binary. Alternatively you can modify your system's library search paths (e.g. LD_LIBRARY_PATH) to ensure that the library is found.

go-spacemesh is p2p software which is designed to form a decentralized network by connecting to other instances of go-spacemesh running on remote computers.

To run go-spacemesh you need to specify the parameters shared between all instances on a specific network.

You specify these parameters by providing go-spacemesh with a json config file. Other CLI flags control local node behavior and override default values.

Joining a Testnet (without mining)

1. Build go-spacemesh from source code.

2. Download the testnet's json config file. Make sure your local config file suffix is .json.

3. Start go-spacemesh with the following arguments:

   ./go-spacemesh --listen [a_multiaddr] --config [configFileLocation] -d [nodeDataFilesPath]

   Example:

   Assuming tn1.json is a testnet config file saved in the same directory as go-spacemesh, use the following command to join the testnet. The data folder will be created in the same directory as go-spacemesh. The node will use TCP port 7513 and UDP port 7513 for p2p connections:

   ./go-spacemesh --listen /ip4/0.0.0.0/tcp/7513 --config ./tn1.json -d ./sm_data

4. Build the CLI Wallet from source code and run it:

5. Use the CLI Wallet commands to setup accounts, start smeshing and execute transactions.

./cli_wallet

Joining a Testnet (with mining)

1. Run go-spacemesh to join a testnet without mining (see above).

2. Run the CLI Wallet to create a coinbase account. Save your coinbase account public address - you'll need it later.

3. Stop go-spacemesh and start it with the following params:

   ./go-spacemesh --listen [a_multiaddr] --config [configFileLocation] -d [nodeDataFilesPath] \
       --smeshing-coinbase [coinbase_account] \
       --smeshing-start --smeshing-opts-datadir [dir_for_post_data]

   Example:

   ./go-spacemesh --listen /ip4/0.0.0.0/tcp/7513 --config ./tn1.json -d ./sm_data \
       --smeshing-coinbase stest1qqqqqqp3qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqql50dsa \
       --smeshing-start --smeshing-opts-datadir ./post_data

4. Use the CLI wallet to check your coinbase account balance and to transact

---

Smeshing

To be able to initialize your PoST using your Graphics card you will need to install the tools necessary to enable OpenCL support on your system. The exact steps to do this will vary based on your OS and GPU. In general you will need to install the OpenCL runtime for your GPU and ICD loader.

A good starting point to get more info is https://wiki.archlinux.org/title/GPGPU.

If your system doesn't have a GPU or you can use a generic runtime instead. Be aware that we do not recommend this for initialization of PoST. On Ubuntu you need to install the following packages:

apt-get update
apt-get install libpocl2

on Windows you can use Intel OpenAPI:

choco install opencl-intel-cpu-runtime

Using a remote machine as provider for PoST proofs

To disable the internal PoST service and disable smeshing on your node you can use the following config:

"smeshing": {
    "smeshing-start": false,
}

or use the --smeshing-start=false flag. This will disable smeshing on your node causing it not generate any PoST proofs until a remote post service connects. Be aware that you still need to set your coinbase via

"smeshing": {
    "smeshing-coinbase": "your coinbase address",
}

or use the --smeshing-coinbase CLI parameter, otherwise your node will not be able to receive rewards.

If you want to allow connections from post services on other hosts to your node, you need to set a public endpoint via the grpc-tls-listener configuration parameter and setup TLS for the connection.

This is useful for example if you want to run a node on a cloud provider with fewer resources and run PoST on a local machine with more resources. The post service only needs to be online for the initial proof (i.e. when joining the network for the first time) and during the cyclegap in every epoch.

To setup TLS-secured public connections the API config has been extended with the following options:

"api": {
  "grpc-tls-listener": "0.0.0.0:9094",           // listen address for TLS connections
  "grpc-tls-ca-cert": "/path/to/ca.pem",         // CA certificate that signed the node's and the PoST service's certificates
  "grpc-tls-cert": "/path/to/cert.pem",          // certificate for the node
  "grpc-tls-key": "/path/to/key.pem",            // private key for the node
}

Ensure that remote PoST services are setup to connect to your node via TLS, that they trust your node's certificate and use a certificate that is signed by the same CA as your node's certificate.

Configuring a remote PoST service

The post service is at the moment configured exclusively via command line parameters:

• --dir specifies the directory containing postdata_metadata.json and the postdata_xxx.bin files; other files in the post directory need to stay with the node!
• --address specifies the address the post service should connect to
• --ca-cert, --cert and --key specify the location of the CA certificate, the post services certificate and the post services key respectively. For more information see below.
• --threads, --nonces and --randomx-mode can be adapted to optimize proof generation. They are analogous to smeshing-opts-proving-threads, smeshing-opts-proving-nonces and smeshing-opts-proving-randomx-mode respectively.
• -h or --help prints a help message with all available options and more details on their usage.

Keys and certificates

The PoST service and the node talk to each other via mTLS and have to authenticate themselves at the opposite end. For this both need keys and certificates.

Here is a script that generates a key & certificate for a CA, a key for the client (PoST service) and a key for the server (node). Then it uses the CAs key to generate certificates from the keys for both the client & server.

Make sure to adjust the certificate extensions & subjects for your setup accordingly.

ca.crt needs to be provided to both the PoST service and the node, server.crt & server.key are only needed by the node and client.crt & client.key are only needed by the PoST service.

# create certificate extensions to allow using them for localhost
cat > server-domains.ext <<EOF
[v3_req]
subjectAltName = @alt_names

[alt_names]
DNS.1 = node
IP.1 = 127.0.0.1
EOF

cat > client-domains.ext <<EOF
[v3_req]
subjectAltName = @alt_names

[alt_names]
DNS.1 = post
EOF

# create CA private key and certificate
openssl req -x509 -newkey rsa:4096 -days 365 -nodes -keyout ca.key -out ca.crt \
    -subj "/C=EN/ST=Spacemesh/L=Tel Aviv/O=Spacemesh/CN=spacemesh.io/[email protected]"

# create server private key and CSR
openssl req -newkey rsa:4096 -nodes -keyout server.key -out server-req.pem \
    -subj "/C=EN/ST=Spacemesh/L=Tel Aviv/O=Server/CN=server.spacemesh.io/[email protected]"

# use CA private key to sign ser CRS and get back the signed certificate
openssl x509 -req -in server-req.pem -days 60 -CA ca.crt -CAkey ca.key -CAcreateserial -out server.crt \
    -extfile server-domains.ext -extensions v3_req
rm server-req.pem

# create client private key and CSR
openssl req -newkey rsa:4096 -nodes -keyout client.key -out client-req.pem \
    -subj "/C=EN/ST=Spacemesh/L=Tel Aviv/O=Client/CN=client.spacemesh.io/[email protected]" \

# use CA private key to sign client CSR and get back the signed certificate
openssl x509 -req -in client-req.pem -days 60 -CA ca.crt -CAkey ca.key -CAcreateserial -out client.crt \
    -extfile client-domains.ext -extensions v3_req
rm client-req.pem

---

Testing

NOTE: if tests are hanging try running ulimit -n 400. some tests require that to work.

TEST_LOG_LEVEL="" make test

The optional TEST_LOG_LEVEL environment variable can be set to change the log level during test execution. If not set, tests won't print any logs. Valid values are the error levels of zapcore

For code coverage you can run:

make cover

This will start a local web service and open your browser to render a coverage report. If you just want to generate a cover profile you can run:

make cover-profile

The generated file will be saved to ./cover.out. It can be loaded into your editor or IDE to view which code paths are covered by tests and which not.

Continuous Integration

We've enabled continuous integration on this repository in GitHub. You can read more about our CI workflows.

Docker

A Dockerfile is included in the project allowing anyone to build and run a docker image:

docker build -t spacemesh .
docker run -d --name=spacemesh spacemesh

Windows

On Windows you will need the following prerequisites:

• Powershell - included by in Windows by default since Windows 7 and Windows Server 2008 R2
• Git for Windows - after installation remove C:\Program Files\Git\bin from System PATH (if present) and add C:\Program Files\Git\cmd to System PATH (if not already present)
• Make - after installation add C:\Program Files (x86)\GnuWin32\bin to System PATH
• Golang
• GCC. There are several ways to install gcc on Windows, including Cygwin. Instead, we recommend tdm-gcc which we've tested.

Close and reopen powershell to load the new PATH. You can then run the command make install followed by make build as on UNIX-based systems.

Running a Local Testnet

• You can run a local Spacemesh Testnet with 6 full nodes, 6 user accounts, and 1 POET support service on your computer using docker.
• The local testnet full nodes are built from this repo.
• This is a great way to get a feel for the protocol and the platform and to start hacking on Spacemesh.
• Follow the steps in our Local Testnet Guide

Improved decentralization and P2P diagnostic features

WARNING! THIS IS EXPERIMENTAL FUNCTIONALITY, USE WITH CARE!

In order to make the p2p network more decentralized, the following options are provided:

• "enable-routing-discovery": true: enables routing discovery for finding new peers, including those behind NAT, ans also for discovering relay nodes which are used for NAT hole punching. Note that hole punching can be done when both ends of the connection are behind an endpoint-independent ("cone") NAT.
• "routing-discovery-advertise": true advertises this node for discovery by other peers, even if it is behind NAT.
• "enable-quic-transport": true: enables QUIC transport which, together with TCP transport, heightens the changes of successful NAT hole punching.
• "enable-tcp-transport": false disables TCP transport. This option is intended to be used for debugging purposes only!
• "static-relays": ["/dns4/relay.example.com/udp/5000/quic-v1/p2p/...", ...] provides a static list of relay nodes for use for NAT hole punching in case of routing discovery based relay search is not to be used.
• "ping-peers": ["p2p_id_1", "p2p_id_2", ...] runs P2P ping against the specified peers, logging the results.

For the purpose of debugging P2P connectivity issues, the following command can also be used:

$ grpcurl -plaintext 127.0.0.1:9093 spacemesh.v1.DebugService.NetworkInfo
{
  "id": "12D3Koo...",
  "listenAddresses": [
    "/ip4/0.0.0.0/tcp/50212",
    "/ip4/0.0.0.0/udp/59458/quic-v1",
    "/p2p-circuit"
  ],
  "knownAddresses": [
    "/ip4/127.0.0.1/tcp/50212",
    "/ip4/127.0.0.1/udp/59458/quic-v1",
    "/ip4/192.168.33.5/tcp/50212",
    "/ip4/192.168.33.5/udp/59458/quic-v1",
    "/ip4/.../tcp/37670/p2p/12D3Koo.../p2p-circuit",
    "/ip4/.../udp/37659/quic-v1/p2p/12D3Koo.../p2p-circuit",
    "/ip4/.../tcp/31960/p2p/12D3Koo.../p2p-circuit",
    "/ip4/.../udp/33377/quic-v1/p2p/12D3Koo.../p2p-circuit"
  ],
  "natTypeUdp": "Cone",
  "natTypeTcp": "Cone",
  "reachability": "Private"
}

Next Steps

• Please visit our wiki
• Browse project go docs
• Spacemesh Protocol video overview

Got Questions?

• Introduce yourself and ask anything on Discord.
• DM @teamspacemesh