Practical overview
When it fits
Use alloy-chains when a Rust project needs canonical EIP-155 chain types or when maintaining the repository's chain registry and generated source.
Who it is for
- Rust developers building blockchain software that needs EIP-155 chain definitions.
- Developers maintaining chain entries in the project's registry.
- Developers building components intended for no_std environments with alloc.
Documented uses
- Use canonical EIP-155 chain types in a Rust blockchain client.
- Add or update a chain in the manual registry and regenerate the corresponding data and Rust source.
- Use chain definitions in Rust workspace components intended to support no_std with alloc.
Requirements & limits
The repository is public and open source, and states that it is dual licensed under Apache-2.0 or MIT. The README lists Rust 1.85.0 as the current minimum supported Rust version.
- The library is written in Rust and targets EIP-155 chain definitions.
- Registry updates are made in registry/manual.json; the script generates assets/chains.json and src/generated/.
- The README says workspace crates should support no_std with alloc.
- The documented minimum supported Rust version is 1.85.0.
Check current requirements in the official documentation. Source-based guidance does not mean OpenViST has run or independently tested this project.
Update the chain registry
Regenerate chain data and Rust source after adding or updating a chain in the manual registry.
Before you start
- Access to the alloy-chains repository
- uv and Python to run the documented registry-update command
Steps
Add or update the chain entry in registry/manual.json.
Run the command below from the repository.
uv run python scripts/update-registry.py
Expected outcome
The script updates assets/chains.json and regenerates the Rust source in src/generated/.
Guide limitations
- The README says not to edit generated files directly.
Sources & review
Source record details
- Source availability
- Active
- Sources checked
- 12 October 2026
- Original website title
- alloy-rs/chains · Official homepage title · retained in its source language

