# Add to your Claude Code skills
git clone https://github.com/snowmead/rust-docs-mcp
README.md
Rustdocs MCP Server
Rust is the language of AI
An MCP (Model Context Protocol) server that provides comprehensive access to
Rust crate documentation, source code analysis, dependency trees, and module
structure visualization. Built for agents to gain quality insights into Rust
projects and build with confidence.
Warning
This is an entirely vibe coded project and was created as an experiment to see if LLMs can build a fully functional tool without human oversight.
The Problem: Agents Building in the Dark
The rise of AI agents has revolutionized software development, with new tools
and libraries emerging at an unprecedented pace. However, this rapid evolution
creates a critical challenge: agents cannot reliably build with tools they
weren't trained on.
When an agent tries to use a new Rust crate:
🚫 Training data is outdated — The model hasn't seen recent crates or API
changes
🚫 Documentation scraping is inefficient — Web scraping GitHub or docs.rs
is slow and unreliable
[x] Dependency analysis — Direct and transitive dependency trees with
metadata
[x] Module structure — Hierarchical tree generation via cargo-modules
integration
[x] Offline operation — Full functionality after initial crate caching
[x] Token management — Response truncation and preview modes for LLM
compatibility
MCP Tools
Cache Management
cache_crate - Download and cache a crate from various sources. Set
source_type to one of: cratesio, github, or local
For cratesio: Provide version (e.g., {crate_name: "serde", source_type: "cratesio", version: "1.0.215"})
For github: Provide github_url and either branch OR tag (e.g., {crate_name: "my-crate", source_type: "github", github_url: "https://github.com/user/repo", tag: "v1.0.0"})
For local: Provide path, optional version (e.g., {crate_name: "my-crate", source_type: "local", path: "~/projects/my-crate"})
remove_crate - Remove cached crate versions to free disk space
list_cached_crates - View all cached crates with versions and sizes
list_crate_versions - List cached versions for a specific crate
get_crates_metadata - Batch metadata queries for multiple crates
Documentation Queries
list_crate_items - Browse all items in a crate with optional filtering
search_items - Full search with complete documentation (may hit token
limits)
search_items_preview - Lightweight search returning only IDs, names, and
types
get_item_details - Detailed information about specific items (signatures,
fields, etc.)
get_item_docs - Extract just the documentation string for an item
get_item_source - View source code with configurable context lines
Dependency Analysis
get_dependencies - Analyze direct and transitive dependencies with filtering
Structure Analysis
structure - Generate hierarchical module tree using integrated cargo-modules
Search
search_items_fuzzy - Fuzzy search with typo tolerance and semantic
similarity
Configuration
Cache Directory
By default, crates are cached in ~/.rust-docs-mcp/cache/. You can customize
this location using:
# Command line option
rust-docs-mcp --cache-dir /custom/path/to/cache
# or set the environment variable
export RUST_DOCS_MCP_CACHE_DIR=/custom/path/to/cache
rust-docs-mcp
GitHub Authentication
To access private repositories or increase GitHub API rate limits, set the
GITHUB_TOKEN environment variable:
Runtime prefers nightly-2025-06-24 because it matches the rustdoc JSON
schema used by rustdoc-types, but it will fall back to nightly when that
toolchain produces the same JSON format version. You can override the choice
with:
git clone https://github.com/snowmead/rust-docs-mcp
cd rust-docs-mcp/rust-docs-mcp
cargo build --release
./target/release/rust-docs-mcp install
CLI Commands
rust-docs-mcp # Start MCP server
rust-docs-mcp install # Install to ~/.local/bin
rust-docs-mcp install --force # Force overwrite existing installation
rust-docs-mcp doctor # Verify system environment and dependencies
rust-docs-mcp doctor --json # Output diagnostic results in JSON format
rust-docs-mcp update # Update to latest version from GitHub
rust-docs-mcp --help # Show help
Troubleshooting
If you encounter issues during installation or runtime, run the doctor command
to diagnose common problems:
rust-docs-mcp doctor
The doctor command checks:
Rust toolchain availability (stable + nightly)
Git installation
Network connectivity to crates.io and GitHub
Cache directory permissions and disk space
Rustdoc JSON generation capability
Optional dependencies (e.g., codesign on macOS)
For programmatic integration, use --json flag to get structured output.
The agent harness performance optimization system. Skills, instincts, memory, security, and research-first development for Claude Code, Codex, Opencode, Cursor and beyond.
