Dociium

Multi-language documentation and code discovery via the Model Context Protocol (MCP).

Dociium enables AI assistants (Claude Desktop, Cline, etc.) to search and retrieve documentation and source code for Rust, Python, and Node.js packages—with semantic search, import resolution, and intelligent caching.

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✨ Features

• Rust: Crate search (crates.io), documentation (docs.rs), trait implementations, symbol search
• Python: Semantic search, source code extraction, class method introspection, universal package manager support (pip, uv, poetry, pdm, conda)
• Node.js: Source code extraction with ESM/CJS support
• Import Resolution: Map use/import/from statements to source locations (Rust/Python/Node)
• CLI + MCP Server: Use as MCP server (stdio/HTTP) or invoke tools directly from command line
• Smart Caching: Multi-layer (in-memory LRU + disk) with metrics and TTL
• Context-Aware: Working directory support for monorepos and multi-virtualenv projects

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🚀 Quick Start

Install

# From crates.io
cargo install dociium

# From source
git clone https://github.com/labiium/dociium.git
cd dociium
cargo install --path .

As MCP Server

Add to your MCP settings (e.g., Claude Desktop claude_desktop_config.json):

{
  "mcpServers": {
    "dociium": {
      "command": "dociium",
      "args": ["stdio"]
    }
  }
}

Then ask your assistant:

• "Search for async http clients on crates.io"
• "Show documentation for tokio::sync::Mutex"
• "Find Python functions for parsing JSON in the requests library"
• "What are all the methods on the Flask class?"

As CLI Tool

# Rust crate search
dociium search-crates "async http"

# Python semantic search
dociium semantic-search requests "make http post request with json"

# Get Python class methods
dociium list-class-methods flask "app.py#Flask"

# Get implementation
dociium get-implementation --language python requests "sessions.py#Session"

# Cache statistics
dociium cache-stats

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🧰 Available Tools

Rust Documentation

Tool	Description	Example
search_crates	Search crates.io	dociium search-crates "async runtime"
crate_info	Get crate metadata	dociium crate-info tokio
get_item_doc	Fetch item docs from docs.rs	dociium get-item-doc tokio "sync::Mutex"
list_trait_impls	List implementations of a trait	dociium list-trait-impls serde "Serialize"
list_impls_for_type	List traits for a type	dociium list-impls-for-type std "Vec"
search_symbols	Search symbols in a crate	dociium search-symbols tokio "spawn"
source_snippet	Get source code (placeholder)	dociium source-snippet tokio "sync::Mutex"

Python & Node.js

Tool	Description	Example
semantic_search	Natural language search	dociium semantic-search requests "retry failed requests"
get_implementation	Get source code	dociium get-implementation -l python requests "api.py#get"
list_class_methods	List all methods of a class	dociium list-class-methods flask "app.py#Flask"
get_class_method	Get specific method	dociium get-class-method flask "app.py#Flask" route
search_package_code	Regex code search	dociium search-package-code -l python flask "async def"

Multi-Language

Tool	Description	Example
resolve_imports	Resolve import statements	Via MCP JSON-RPC
cache_stats	Get cache metrics	dociium cache-stats
clear_cache	Clear cache	dociium clear-cache
cleanup_cache	Remove expired entries	dociium cleanup-cache

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🔎 Python Semantic Search

The standout feature for Python developers. Search packages using natural language:

dociium semantic-search requests "create session with retry logic"

How it works:

• TF-IDF scoring over function names, docstrings, signatures, and module paths
• Indexes public symbols (functions and classes) from installed packages
• First search builds index (0.5-3s), subsequent searches <10ms
• Results include relevance scores, signatures, docstring previews, and source locations

MCP JSON-RPC:

{
  "method": "tools/call",
  "params": {
    "name": "semantic_search",
    "arguments": {
      "language": "python",
      "package_name": "requests",
      "query": "send authenticated http request",
      "limit": 5
    }
  }
}

Score interpretation:

• 0.9+: Excellent match
• 0.7-0.9: Good match
• 0.5-0.7: Moderate relevance
• <0.5: Weak match

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🐍 Python Package Discovery

Works with any Python package manager—no pip required!

Multi-level fallback strategy:

1. Environment variables (highest priority)

   • DOC_PYTHON_PACKAGE_PATH_<PKG> or DOC_PYTHON_PACKAGE_PATH

2. Native introspection (pure Rust, no Python runtime needed)

   • Scans virtual environments: .venv, venv, $VIRTUAL_ENV
   • Checks user site-packages: ~/.local/lib/python*/site-packages
   • Scans system locations: /usr/local/lib, /opt/homebrew/lib

3. pip show (if pip available)

4. uv pip show (if uv available)

5. Direct filesystem scan (last resort)

Supported package managers:

• pip
• uv
• poetry
• pdm
• conda
• pipenv
• Any tool that installs to standard site-packages

Context-aware resolution: Use context_path parameter to target specific project virtualenvs:

dociium semantic-search --context /path/to/project mypackage "find something"

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🧩 Import Resolution

Resolve import/use statements to their source locations:

Rust:

use tokio::sync::Mutex;
use std::collections::HashMap;

Python:

from requests import Session
from requests.adapters import HTTPAdapter

Node.js:

import { Router } from 'express';
import * as utils from './utils.js';

Returns file paths and line numbers for each imported symbol.

Limitations:

• Best-effort heuristics (not a full compiler)
• Macro-expanded items (Rust) not resolved
• Dynamic imports (Python __getattr__) not detected
• Complex re-export chains may be incomplete

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🗄️ Caching

Multi-layer architecture:

Layer	Storage	Purpose
Memory LRU	In-process	Hot crate docs, versions
Disk (items)	Gzipped files	Individual Rust item docs
Disk (indexes)	JSON	Parsed search-index.js
Import cache	In-process LRU+TTL	Import resolution (5min TTL)
Semantic index	In-process	Python package TF-IDF vectors

Cache metrics:

dociium cache-stats

Returns hit rates, miss rates, evictions, total entries, and oldest entry age.

Cache management:

# Clear all caches
dociium clear-cache

# Clear specific crate
dociium clear-cache --crate-name tokio

# Remove expired entries
dociium cleanup-cache

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⚙️ Configuration

Cache Directory

Priority:

1. CLI flag: --cache-dir <path>
2. Env: RDOCS_CACHE_DIR
3. Platform default: $XDG_CACHE_HOME/dociium (Linux), ~/Library/Caches/dociium (macOS)
4. Fallback: ./.dociium-cache

Working Directory

Set programmatically when embedding:

use dociium::doc_engine::{DocEngine, DocEngineOptions};
use std::path::PathBuf;

let options = DocEngineOptions {
    working_dir: Some(PathBuf::from("/path/to/project")),
};
let engine = DocEngine::new_with_options("./cache", options).await?;

Or use context_path in tool calls (resolved relative to working directory).

Environment Overrides

Force package locations:

export DOC_PYTHON_PACKAGE_PATH_requests=/custom/path/to/requests
export DOC_NODE_PACKAGE_PATH_express=/custom/path/to/express

HTTP Server Mode

Run as HTTP server instead of stdio:

dociium http --http-listen 127.0.0.1:7777

Options:

• --http-listen <addr:port>: Bind address (required)
• --http-path <path>: Endpoint prefix (default /mcp)
• --http-keep-alive-secs <n>: SSE ping interval (default 30, 0=disabled)
• --http-stateless: Disable per-session state

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🔐 Security

• Path sanitization: All file paths validated and normalized
• Input validation: Length and charset checks on crate names, versions, queries
• Timeout protection: All network calls have configurable timeouts
• No shell execution: All external commands use structured APIs (no eval)
• Safe parsing: Fallback-based parsing prevents crashes on malformed data

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🧪 Testing

# All tests
cargo test

# With network tests (requires internet)
ENABLE_NETWORK_TESTS=1 cargo test

# Linting
cargo clippy --all-targets -- -D warnings

# Format check
cargo fmt --check

Test coverage:

• Integration tests for all MCP tools
• Unit tests for cache, search, import resolution
• Network tests (gated by env var)
• Cache metrics validation

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📈 Roadmap

Near-term:

• Real Rust source snippet extraction (currently placeholder)
• Improved multi-hop import resolution
• Richer cache eviction policies
• Performance metrics export (Prometheus/OpenTelemetry)

Medium-term:

• Python __all__ and re-export handling
• Node.js barrel file resolution
• Pluggable search backends (Tantivy integration)
• Persistent import cache

Long-term:

• Full rustdoc JSON ingestion
• Language server protocol (LSP) integration
• Multi-language semantic search
• Distributed cache sharing

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🛠️ Development

# Clone and build
git clone https://github.com/labiium/dociium.git
cd dociium
cargo build --release

# Run as stdio MCP server
./target/release/dociium stdio

# Run as HTTP server
./target/release/dociium http --http-listen 127.0.0.1:7777

# Direct CLI usage
./target/release/dociium search-crates tokio

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📜 License

Dual-licensed under MIT OR Apache-2.0.

See LICENSE-MIT and LICENSE-APACHE for details.

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🙌 Contributing

Contributions welcome! Please:

1. Open an issue describing the enhancement or fix
2. Include tests (integration and/or unit)
3. Maintain backward compatibility for MCP tool schemas
4. Run cargo clippy and cargo fmt before submitting

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Dociium - Keep your AI assistant grounded in real code and documentation.

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