Rust Docs MCP Server - Overview

Title

Rust Docs MCP Server

A server that fetches and processes Rust crate documentation, enabling AI coding assistants to provide accurate, up-to-date answers about specific crates via semantic search and LLM summarization.

How to Use

Installation

1. Download Pre-Compiled Binary:

   • Visit the GitHub Releases page.
   • Download the appropriate binary for your OS (Windows/macOS/Linux).
   • Place it in a directory listed in your system’s PATH.

2. Build from Source (Optional):

   • Requires the Rust toolchain (rustup).
   • Clone the repo and run cargo build --release.

Running the Server

1. Set your OpenAI API key:

   export OPENAI_API_KEY="sk-..."  

2. Start the server with a crate specification (e.g., serde@^1.0, tokio).

   rustdocs_mcp_server "crate_name@version" --features "feat1,feat2"  

3. For first-time use with a crate, allow time for documentation download and embedding generation (~minutes). Subsequent runs use cached data for faster startup.

MCP Integration

• The server exposes a tool (query_rust_docs) for AI assistants to query crate documentation.
• Example MCP call:

  {  
    "method": "callTool",  
    "params": {  
      "tool_name": "query_rust_docs",  
      "arguments": {  
        "question": "How to make a GET request with reqwest?"  
      }  
    }  
  }  

Key Features

• Targeted Documentation: Focuses on a single Rust crate per instance.
• Semantic Search: Uses OpenAI embeddings to find relevant documentation sections.
• LLM Summarization: Generates concise answers using gpt-4o-mini.
• Feature Support: Allows specifying crate features for accurate docs.
• Caching: Stores docs and embeddings locally (~/.local/share/rustdocs-mcp-server/) to avoid repeated costs.
• MCP Compliance: Runs over stdio for seamless integration with AI coding tools.

Use Cases

• AI Coding Assistants: Provide accurate, up-to-date Rust crate API answers (e.g., for serde, tokio, or reqwest).
• Development Workflow: Reduce manual corrections by ensuring LLM suggestions align with the latest crate versions.
• Multi-Crate Projects: Run multiple server instances for different crates simultaneously.

License: MIT
GitHub: https://github.com/Govcraft/rust-docs-mcp-server