9 releases

0.26.0 Apr 30, 2024
0.25.3 Apr 24, 2024
0.24.3 Apr 24, 2024
0.24.1 Mar 30, 2024

#2523 in Magic Beans

Download history 427/week @ 2024-03-30 53/week @ 2024-04-06 250/week @ 2024-04-13 369/week @ 2024-04-20 146/week @ 2024-04-27 19/week @ 2024-05-04

785 downloads per month
Used in 3 crates (via fuel-core-upgradable-exec…)


10K SLoC

Fuel Client

build crates.io docs discord

Fuel client implementation.


If you are interested in contributing to Fuel, see our CONTRIBUTING.md guidelines for coding standards and review process.

Before pushing any changes or creating pull request please run source ci_checks.sh.


System Requirements

There are several system requirements including clang.


brew update
brew install cmake


apt update
apt install -y cmake pkg-config build-essential git clang libclang-dev


pacman -Syu --needed --noconfirm cmake gcc pkgconf git clang


We recommend using xtask to build fuel-core:

cargo xtask build

This will run cargo build as well as any other custom build processes we have such as re-generating a GraphQL schema for the client.


The ci_checks.sh script file can be used to run all CI checks, including the running of tests.

source ci_checks.sh

The script requires pre-installed tools. For more information run:

cat ci_checks.sh


The service can be launched by executing fuel-core run. The list of options for running can be accessed via the help option:

$ ./target/debug/fuel-core run --help

    fuel-core run [OPTIONS]

        --chain <CHAIN_CONFIG>
            Specify either an alias to a built-in configuration or filepath to a JSON file [default:

For many development purposes it is useful to have a state that won't persist and the db-type option can be set to in-memory as in the following example.


$ ./target/debug/fuel-core run --db-type in-memory
2023-06-13T12:45:22.860536Z  INFO fuel_core::cli::run: 230: Block production mode: Instant
2023-06-13T12:38:47.059783Z  INFO fuel_core::cli::run: 310: Fuel Core version v0.18.1
2023-06-13T12:38:47.078969Z  INFO new{name=fuel-core}:_commit_result{block_id=b1807ca9f2eec7e459b866ecf69b68679fc6b205a9a85c16bd4943d1bfc6fb2a height=0 tx_status=[]}: fuel_core_importer::importer: 231: Committed block
2023-06-13T12:38:47.097777Z  INFO new{name=fuel-core}: fuel_core::graphql_api::service: 208: Binding GraphQL provider to

To disable block production on your local node, set --poa-instant=false


$ ./target/debug/fuel-core run --poa-instant=false
2023-06-13T12:44:12.857763Z  INFO fuel_core::cli::run: 232: Block production disabled



We use publish-crates action for automatic publishing of all crates.

If you have problems with publishing, you can troubleshoot it locally with act.

act release -s GITHUB_TOKEN=<YOUR_GITHUB_TOKEN> -j publish-crates-check --container-architecture linux/amd64 --reuse

It requires GitHubToken to do request to the GitHub. You can create it with this instruction.

Outdated database

If you encounter an error such as

thread 'main' panicked at 'unable to open database: DatabaseError(Error { message: "Invalid argument: Column families not opened: column-11, column-10, column-9, column-8, column-7, column-6, column-5, column-4, column-3, column-2, column-1, column-0" })', fuel-core/src/main.rs:23:66

Clear your local database using: rm -rf ~/.fuel/db

File descriptor limits

On some macOS versions the default file descriptor limit is quite low, which can lead to IO errors with messages like Too many open files or even fatal runtime error: Rust cannot catch foreign exceptions when RocksDB encounters these issues. Use the following command to increase the open file limit. Note that this only affects the current shell session, so consider adding it to ~/.zshrc.

ulimit -n 10240

Log level

The service relies on the environment variable RUST_LOG. For more information, check the EnvFilter examples crate.

Human logging can be disabled with the environment variable HUMAN_LOGGING=false


See the guide on debugging for an overview on running a debug build of a local node.

Docker & Kubernetes

# Create Docker Image
docker build -t fuel-core . -f deployment/Dockerfile

# Delete Docker Image
docker image rm fuel-core

# Create Kubernetes Volume, Deployment & Service
kubectl create -f deployment/fuel-core.yml

# Delete Kubernetes Volume, Deployment & Service
kubectl delete -f deployment/fuel-core.yml

GraphQL service

The client functionality is available through a service endpoint that expect GraphQL queries.

Transaction executor

The transaction executor currently performs instant block production. Changes are persisted to RocksDB by default.

  • Service endpoint: /v1/graphql
  • Schema (available after building): crates/client/assets/schema.sdl

The service expects a mutation defined as submit that receives a Transaction in hex encoded binary format, as specified here.

cURL example

This example will execute a script that represents the following sequence of ASM:

ADDI(0x10, RegId::ZERO, 0xca),
ADDI(0x11, RegId::ZERO, 0xba),
LOG(0x10, 0x11, RegId::ZERO, RegId::ZERO),
$ cargo run --bin fuel-core-client -- transaction submit \
  \"CoinSigned\": {
    \"utxo_id\": {
      \"tx_id\": \"c49d65de61cf04588a764b557d25cc6c6b4bc0d7429227e2a21e61c213b3a3e2\",
      \"output_index\": 0
    \"owner\": \"f1e92c42b90934aa6372e30bc568a326f6e66a1a0288595e6e3fbd392a4f3e6e\",
    \"amount\": 10599410012256088338,
    \"asset_id\": \"2cafad611543e0265d89f1c2b60d9ebf5d56ad7e23d9827d6b522fd4d6e44bc3\",
    \"tx_pointer\": {
      \"block_height\": 0,
      \"tx_index\": 0
    \"witness_index\": 0,
    \"maturity\": 0,
    \"predicate_gas_used\": null,
    \"predicate\": null,
    \"predicate_data\": null
  \"data\": [


The library defines some common parts used by the WASM executor and upgradable executor.


~372K SLoC