MCP RAG Server

mcp-rag-server is a Model Context Protocol (MCP) server that enables Retrieval Augmented Generation (RAG) capabilities for connected LLMs. It indexes documents from your project and provides relevant context to enhance LLM responses.

Built with Google Genkit, ChromaDB, and Ollama.

Quick Start

(Provide a minimal runnable example here, assuming Docker setup is complete)

# Example: Querying via an MCP client (conceptual)
# (Actual usage depends on the client implementation)

Why Choose This Project?

• Seamless MCP Integration: Designed specifically for the Model Context Protocol ecosystem.
• Local Control: Leverages local models (Ollama) and vector stores (ChromaDB) for privacy and customization.
• Automatic Context: Indexes your project files automatically to provide relevant context to LLMs.
• Extensible: Built with Genkit, allowing for potential future extensions and integrations.

Features

• Automatic Indexing: Scans the project directory on startup (configurable) and indexes supported files.
• Supported File Types: .txt, .md, code files (via generic splitting), .json, .jsonl, .csv. (Code file chunking is basic).
• Hierarchical Chunking: Intelligently chunks Markdown files, separating text and code blocks.
• Vector Storage: Uses ChromaDB for persistent vector storage.
• Local Embeddings: Leverages Ollama for local embedding generation (default: nomic-embed-text).
• MCP Tools: Exposes RAG functions as standard MCP tools:
  • indexDocuments: Manually index a file or directory.
  • queryDocuments: Retrieve relevant document chunks for a query.
  • removeDocument: Remove a specific document's chunks by source path.
  • removeAllDocuments: Clear the entire index for the current project.
  • listDocuments: List indexed document source paths.
• Dockerized: Includes a docker-compose.yml for easy setup of the server, ChromaDB, and Ollama.

Design Philosophy

• Simplicity: Aims for a straightforward setup and usage experience, especially with Docker Compose.
• Modularity: Leverages Genkit flows for organizing RAG logic.
• Local-First: Prioritizes local tools like Ollama and ChromaDB for core functionality.

Installation & Usage (Docker Compose - Recommended)

This method runs the server and its dependencies (ChromaDB, Ollama) in isolated containers.

1. Prerequisites:

   • Install Docker Desktop or Docker Engine.
   • Ensure port 8000 (ChromaDB) and 11434 (Ollama) are free on your host machine, or adjust ports in docker-compose.yml.

2. Clone the Repository:

   git clone https://github.com/sylphlab/rag-server-mcp.git
   cd mcp-rag-server
   

3. Start Services:

   docker-compose up -d --build
   

   • This builds the server image, downloads ChromaDB and Ollama images, and starts the services.
   • The first run might take time to download images and build.

4. Pull Embedding Model (First Run): The default embedding model (nomic-embed-text) needs to be pulled into the Ollama container after it starts.

   docker exec ollama ollama pull nomic-embed-text
   

   • Wait a few moments after docker-compose up before running this. You only need to do this once as the model will be persisted in a Docker volume.

5. Integration with MCP Client: Configure your MCP client (e.g., in VS Code settings or another MCP server) to connect to this server. Since it's running via Docker Compose, you typically don't run it via npx directly in the client config. Instead, the client needs to know how to communicate with the running server (which isn't directly exposed by default in this setup, usually communication happens via other means like direct API calls if the server exposed an HTTP interface, or via shared volumes/databases if applicable).

   Note: The current setup primarily facilitates RAG via Genkit flows within this project or potentially other services within the same Docker network. Direct MCP client integration from an external host requires exposing the server's MCP port from the Docker container.

Configuration (Environment Variables)

Configure the server via environment variables, typically set within the docker-compose.yml file for the rag-server service:

• CHROMA_URL: URL of the ChromaDB service. (Default in compose: http://chromadb:8000)
• OLLAMA_HOST: URL of the Ollama service. (Default in compose: http://ollama:11434)
• INDEX_PROJECT_ON_STARTUP: Set to true (default) or false to enable/disable automatic indexing on server start.
• INDEXING_EXCLUDE_PATTERNS: Comma-separated list of glob patterns to exclude from indexing (e.g., **/node_modules/**,**/.git/**). Defaults are defined in autoIndexer.ts.
• GENKIT_ENV: Set to production or development (influences logging, etc.).
• LOG_LEVEL: Set log level (e.g., debug, info, warn, error).

(See docker-compose.yml and src/config/genkit.ts for more details)

Performance

(Performance benchmarks are not yet available.)

Comparison with Other Solutions

(Comparison with other RAG solutions will be added later.)

Future Plans

• Improve code file chunking strategies.
• Add support for more file types (e.g., PDF).
• Enhance filtering capabilities for queries.
• Investigate and resolve E2E test failures.
• Add more robust error handling.

Development

1. Prerequisites: Node.js (LTS), npm.
2. Install Dependencies: npm install
3. Build: npm run build
4. Run Linters/Formatters:
   • npm run lint
   • npm run format
   • npm run validate (runs format check, lint, typecheck, tests)
5. Run Tests:
   • npm test (runs unit tests)
   • npm run test:cov (runs unit tests with coverage)
   • E2E Tests: Require Docker Compose environment running (docker-compose up -d). Run specific E2E tests via Vitest commands or potentially integrate into npm test. (Note: E2E tests are currently failing due to external service interaction issues).
6. Run Server Locally (without Docker):
   • Ensure ChromaDB and Ollama are running and accessible (e.g., locally installed or separate Docker containers).
   • Set environment variables (CHROMA_URL, OLLAMA_HOST).
   • npm start

Documentation

Full documentation is available at [TODO: Add link to deployed VitePress site].

Contributing

Contributions are welcome! Please open an issue to discuss changes before submitting a pull request. Follow coding standards and commit conventions.

License

This project is licensed under the MIT License.