rust-crate-src

Fetch Rust crate source code from crates.io. Available as a library and MCP server.

Installing

Install via cargo:

cargo install rust-crate-src-mcp

Configure in your mcp.json:

{
  "mcpServers": {
    "rust-crate-src": {
      "command": "rust-crate-src-mcp"
    }
  }
}

Usage

As a Library

use rust_crate_src::get_crate_source;

let source = get_crate_source("serde", None).await?;
println!("Extracted to: {}", source.checkout_path.display());

// With version constraint
let source = get_crate_source("tokio", Some("^1.0")).await?;

MCP Tool

Exposes the get_rust_crate_source tool:

• crate_name (required): Name of the crate to fetch
• version (optional): Semver version constraint (e.g., "1.0", "^1.2", "~1.2.3")

Returns:

• crate_name: Echo of requested crate
• version: Resolved exact version
• checkout_path: Path to extracted source
• message: Human-readable summary

Development

make check    # Run all checks (test + lint + format) - REQUIRED before commits
make format   # Auto-format code
make test     # Run unit tests
make integ    # Run integration tests (requires network)

Architecture

For AI Agents

See AGENTS.md for development guidelines.

Acknowledgments

This project is based on the get_rust_crate_source tool from symposium.

License

Licensed under either of Apache License, Version 2.0 or MIT license at your option.