chainlist-rs

Typed access to EVM chain metadata generated from chainid.network/chains.json. The build script downloads the JSON on every build and turns it into a Chain enum with helpers for IDs, names, native currency, RPC URLs, and block times.

Quick start

Add to your Cargo.toml:

chainlist-rs = "0.1"

Use the enum:

use chainlist_rs::Chain;

fn main() {
    let mainnet = Chain::Mainnet;
    println!(
        "{} (id {}) uses {}",
        mainnet.name(),
        mainnet.id(),
        mainnet.native_currency().1
    );
}

Examples:

• cargo run --example print_chain
• cargo run --example wallet_params
• cargo run --example list_chains
• Access full chain table: let chains = chainlist_rs::all_chains();

Data source

• chains.json is downloaded at build time from https://chainid.network/chains.json (network required).
• Override with CHAINS_JSON_URL to point to your mirror, or CHAINS_JSON_PATH if you want to supply a local file explicitly.
• The downloaded file is kept in the build output dir and is ignored by git.

Developing & releasing

• Builds require network access to fetch chains.json unless you provide CHAINS_JSON_PATH.
• Quality gates: cargo fmt, cargo clippy --all-targets --all-features, cargo test.
• CI: PRs/pushes run fmt/clippy/tests with CHAINS_JSON_PATH=data/chains.json to stay offline.
• Publish check: cargo package --dry-run (or cargo publish --dry-run) to verify the crate contents and metadata.
• Automated release: pushing a tag vX.Y.Z runs checks (fmt/clippy/tests) and publishes with cargo publish --locked when CARGO_REGISTRY_TOKEN is set in repo secrets; the tag must match the crate version.
• Coverage: CI runs cargo llvm-cov --lcov with CHAINS_JSON_PATH=data/chains.json and uploads to Codecov (set CODECOV_TOKEN if the repo is private).

License

MIT OR Apache-2.0 (dual license).