MCP Server with Self-hosted LLM and Supabase Integration

A comprehensive Model Context Protocol (MCP) server that integrates with self-hosted LLM models via Ollama and Supabase database for data persistence and retrieval.

Features

• MCP Protocol Support: Full implementation of the Model Context Protocol specification

• Self-hosted LLM Integration: Support for Ollama-based LLM models (Llama2, CodeLlama, etc.)

• Supabase Database Integration: Complete CRUD operations with Supabase

• Docker Support: Containerized deployment with Docker Compose

• Comprehensive Testing: Unit tests with ≥90% coverage, integration tests, and E2E tests

• TypeScript: Fully typed implementation for better development experience

• Logging: Structured logging with configurable levels and formats

Architecture

┌─────────────────┐    ┌─────────────────┐    ┌─────────────────┐
│   MCP Client    │    │   MCP Server    │    │   Supabase DB   │
│                 │◄──►│                 │◄──►│                 │
└─────────────────┘    └─────────────────┘    └─────────────────┘
                              │
                              ▼
                       ┌─────────────────┐
                       │   Ollama LLM    │
                       │   (Self-hosted) │
                       └─────────────────┘

Quick Start

Prerequisites

• Docker and Docker Compose

• Node.js 18+ (for local development)

• Supabase account and project

1. Clone and Setup

git clone <repository-url>
cd mcp-server-selfhosted
cp env.example .env

2. Configure Environment

Edit .env file with your configuration:

# Supabase Configuration
SUPABASE_URL=your_supabase_url_here
SUPABASE_ANON_KEY=your_supabase_anon_key_here
SUPABASE_SERVICE_ROLE_KEY=your_supabase_service_role_key_here

# Self-hosted LLM Configuration
LLM_BASE_URL=http://localhost:11434
LLM_MODEL=llama2
LLM_TIMEOUT=30000

# MCP Server Configuration
MCP_SERVER_PORT=3000
MCP_SERVER_HOST=localhost

# Logging
LOG_LEVEL=info
LOG_FORMAT=json

3. Start with Docker Compose

docker-compose up -d

This will start:

• Ollama service (self-hosted LLM)

• MCP Server

• Health checks and monitoring

4. Verify Installation

# Check if services are running
docker-compose ps

# Test MCP server health
curl http://localhost:3000/health

# Test Ollama connection
curl http://localhost:11434/api/tags

5. Test Build Locally (Optional)

# Test TypeScript compilation
npm run build

# Test HTTP server
npm run start:http

# Test health endpoint
curl http://localhost:3000/health

Available Tools

The MCP server provides the following tools:

1. query_database

Execute SQL queries on the Supabase database.

Parameters:

• query (string, required): SQL query to execute

• table (string, optional): Table name for context

Example:

{
  "name": "query_database",
  "arguments": {
    "query": "SELECT * FROM users WHERE active = true",
    "table": "users"
  }
}

2. generate_text

Generate text using the self-hosted LLM.

Parameters:

• prompt (string, required): Text prompt for the LLM

• maxTokens (number, optional): Maximum tokens to generate

• temperature (number, optional): Temperature for generation (0.0-1.0)

Example:

{
  "name": "generate_text",
  "arguments": {
    "prompt": "Explain quantum computing in simple terms",
    "maxTokens": 500,
    "temperature": 0.7
  }
}

3. store_data

Store data in the Supabase database.

Parameters:

• table (string, required): Table name to store data

• data (object, required): Data to store

Example:

{
  "name": "store_data",
  "arguments": {
    "table": "documents",
    "data": {
      "title": "My Document",
      "content": "Document content here",
      "author": "John Doe"
    }
  }
}

4. retrieve_data

Retrieve data from the Supabase database.

Parameters:

• table (string, required): Table name to retrieve data from

• filters (object, optional): Filters to apply

• limit (number, optional): Maximum number of records to retrieve

Example:

{
  "name": "retrieve_data",
  "arguments": {
    "table": "documents",
    "filters": {
      "author": "John Doe"
    },
    "limit": 10
  }
}

Development

Local Development Setup

1. Install Dependencies:

npm install

2. Start Ollama (if not using Docker):

# Install Ollama
curl -fsSL https://ollama.ai/install.sh | sh

# Pull a model
ollama pull llama2

# Start Ollama
ollama serve

3. Start Supabase (if using local instance):

# Install Supabase CLI
npm install -g supabase

# Start local Supabase
supabase start

4. Run Development Server:

npm run dev

Testing

The project includes comprehensive testing:

# Run unit tests
npm test

# Run tests with coverage
npm run test:coverage

# Run E2E tests
npm run test:e2e

# Run all tests
npm run test && npm run test:e2e

Code Quality

# Lint code
npm run lint

# Fix linting issues
npm run lint:fix

Docker Configuration

Dockerfile

The Dockerfile creates an optimized production image:

• Node.js 18 Alpine base

• Non-root user for security

• Health checks

• Multi-stage build for smaller image size

Docker Compose

The docker-compose.yml orchestrates:

• Ollama service for LLM

• MCP Server

• Health checks and dependencies

• Volume persistence for Ollama models

Security Considerations

1. SQL Injection Protection: Basic sanitization of SQL queries

2. Environment Variables: Sensitive data stored in environment variables

3. Non-root Container: Docker containers run as non-root user

4. Input Validation: Zod schemas for input validation

5. Error Handling: Comprehensive error handling without information leakage

Monitoring and Logging

Log Levels

• DEBUG: Detailed debugging information

• INFO: General information messages

• WARN: Warning messages

• ERROR: Error messages

Log Formats

• text: Human-readable format

• json: Structured JSON format for log aggregation

Health Checks

• HTTP endpoint: GET /health

• Docker health checks

• Service dependency checks

Troubleshooting

Common Issues

1. Ollama Connection Failed

   # Check if Ollama is running
   curl http://localhost:11434/api/tags
   
   # Restart Ollama service
   docker-compose restart ollama

2. Supabase Connection Failed

   # Verify environment variables
   echo $SUPABASE_URL
   echo $SUPABASE_ANON_KEY
   
   # Test connection
   curl -H "Authorization: Bearer $SUPABASE_ANON_KEY" $SUPABASE_URL/rest/v1/

3. MCP Server Not Starting

   # Check logs
   docker-compose logs mcp-server
   
   # Check health
   curl http://localhost:3000/health

4. Docker Build Fails with "tsc: not found"

   # This is fixed in the current Dockerfile
   # The issue was NODE_ENV=production preventing dev dependencies installation
   # Solution: Set NODE_ENV=development during build phase
   
   # If you still encounter issues, try:
   docker-compose build --no-cache

5. TypeScript Compilation Errors

   # Test build locally first
   npm run build
   
   # Check for missing dependencies
   npm install
   
   # Clear node_modules and reinstall
   rm -rf node_modules package-lock.json
   npm install

Performance Optimization

1. LLM Performance

   • Use GPU-enabled Ollama for better performance

   • Adjust model parameters (temperature, max_tokens)

   • Consider model size vs. quality trade-offs

2. Database Performance

   • Use connection pooling

   • Optimize SQL queries

   • Consider indexing strategies

Contributing

1. Fork the repository

2. Create a feature branch

3. Make your changes

4. Add tests for new functionality

5. Ensure all tests pass

6. Submit a pull request

License

MIT License - see LICENSE file for details.

Support

For issues and questions:

• Create an issue in the repository

• Check the troubleshooting section

• Review the test cases for usage examples