Cratedocs MCP

🚀 CrateDocs MCP Server

This is a server that adheres to the Model Context Protocol (MCP), providing a tool for Rust crate documentation lookup. It enables large language models (LLMs) to look up documentation for crates they are unfamiliar with.

✨ Features

• Lookup crate documentation: Retrieve general documentation for a specific Rust crate.
• Search for crates: Search for crates on crates.io using keywords.
• Lookup item documentation: Obtain documentation for specific items (e.g., structs, functions, traits) within a crate.

📦 Installation

git clone https://github.com/d6e/cratedocs-mcp.git
cd cratedocs-mcp
cargo build --release

💻 Usage Examples

Basic Usage

Running the Server

There are multiple ways to run the documentation server:

Using the Unified CLI

The unified command-line interface provides subcommands for all server modes:

# Run in STDIN/STDOUT mode
cargo run --bin cratedocs stdio

# Run in HTTP/SSE mode (default address: 127.0.0.1:8080)
cargo run --bin cratedocs http

# Run in HTTP/SSE mode with a custom address
cargo run --bin cratedocs http --address 0.0.0.0:3000

# Enable debug logging
cargo run --bin cratedocs http --debug

Testing the Documentation Tool Directly

You can directly test the documentation tool from the command line without starting the server:

# Get help for the help command
cargo run --bin cratedocs test --tool help

# Look up crate documentation
cargo run --bin cratedocs test --tool lookup_crate --crate-name tokio

# Look up documentation for a specific item
cargo run --bin cratedocs test --tool lookup_item --crate-name tokio --item-path sync::mpsc::Sender

# Look up documentation for a specific version
cargo run --bin cratedocs test --tool lookup_item --crate-name serde --item-path Serialize --version 1.0.147

# Search for crates
cargo run --bin cratedocs test --tool search_crates --query logger --limit 5

# Output in different formats (Markdown, plain text, JSON)
cargo run --bin cratedocs test --tool search_crates --query logger --format markdown
cargo run --bin cratedocs test --tool search_crates --query logger --format plain
cargo run --bin cratedocs test --tool search_crates --query logger --format json

# Redirect output to a file
cargo run --bin cratedocs test --tool search_crates --query logger --format markdown > output.md

Advanced Usage

Available Tools

lookup_crate

Look up documentation for a specific crate.

Parameters:

• --crate-name: Specify the name of the crate to look up (required).
• --version: Specify the version of the crate (optional, default is the latest version).

Example JSON output:

{
  "name": "tokio",
  "version": "1.0.0",
  "documentation_url": "https://docs.rs/tokio/latest/tokio/",
  "description": "A runtime for async tasks built on the Rust programming language."
}

search_crates

Search for crates on crates.io.

Parameters:

• --query: Specify the search keyword (required).
• --limit: Specify the number of results to return (optional, default is 10).
• --format: Specify the output format (optional, supports markdown, plain, or json).

Example JSON output:

[
  {
    "name": "tokio",
    "version": "1.0.0",
    "documentation_url": "https://docs.rs/tokio/latest/tokio/",
    "description": "A runtime for async tasks built on the Rust programming language."
  },
  {
    "name": "serde",
    "version": "1.0.0",
    "documentation_url": "https://docs.rs/serde/latest/serde/",
    "description": "A library for serializing and deserializing data represented as Rust structs."
  }
]

lookup_item

Look up documentation for a specific item within a crate.

Parameters:

• --crate-name: Specify the name of the crate (required).
• --item-path: Specify the path of the item to look up (e.g., sync::mpsc::Sender) (required).
• --version: Specify the version of the crate (optional, default is the latest version).

Example JSON output:

{
  "name": "tokio",
  "version": "1.0.0",
  "item_path": "sync::mpsc::Sender",
  "documentation_url": "https://docs.rs/tokio/latest/tokio/sync/mpsc/Sender/",
  "description": "A message channel type that allows sending messages between tasks."
}

🔧 Technical Details

• Caching mechanism: The server uses caching to improve performance and avoid redundant lookups of the same data.
• Interfaces: The server integrates with APIs such as docs.rs and crates.io to obtain crate documentation and information.
• Result format: The output results are in JSON format, supporting multiple formats including Markdown, plain text, and JSON.

📚 Documentation

MCP Protocol Integration

The CrateDocs server adheres to the Model Context Protocol (MCP), allowing it to integrate with MCP-supporting large language model (LLM) clients. This integration enables LLMs to more efficiently access and understand Rust crate documentation, thereby providing better code generation and problem-solving capabilities.