mcp-db-server

An MCP (Model Context Protocol) server that exposes relational databases (PostgreSQL/MySQL) to AI agents with natural language query support. Transform natural language questions into SQL queries and get structured results.

Features

• Multi-Database Support: Works with PostgreSQL and MySQL
• Natural Language to SQL: Convert plain English queries to SQL using HuggingFace transformers
• RESTful API: Clean FastAPI-based endpoints for database operations
• Safety First: Read-only operations with query validation and result limits
• Docker Ready: Complete containerization with Docker Compose
• Production Ready: Health checks, logging, and error handling
• AI Agent Friendly: Designed specifically for AI agent integration

Version 1.4.0 Changes

• Added mandatory X-API-Key authentication for all database HTTP endpoints; /health remains public for health checks.
• Removed unrestricted credentialed CORS and made allowed origins explicitly configurable.
• Changed the default HTTP bind address to 127.0.0.1.
• Added table-name validation against existing database tables to block SQL injection through table routes.
• Added PostgreSQL sslmode=require compatibility for asyncpg connections.
• Updated Docker Compose, environment examples, and documentation for secure API-key configuration.
• Published Docker images:
  • souhardyak/mcp-db-server:1.4.0
  • souhardyak/mcp-db-server:latest
• Added GitHub Container Registry publishing for:
  • ghcr.io/souhar-dya/mcp-db-server:1.4.0
  • ghcr.io/souhar-dya/mcp-db-server:latest

API Endpoints

Quick Start

Option 1: Docker Compose (Recommended)

1. Clone and start the services:

   server.ts

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   git clone https://github.com/Souhar-dya/mcp-db-server.git
   cd mcp-db-server
   export MCP_API_KEY="$(openssl rand -hex 32)"
   docker-compose up --build
   

2. Test the endpoints:

   bash

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   # Health check
   curl http://localhost:8000/health
   
   # List tables (requires the configured API key)
   curl -H "X-API-Key: $MCP_API_KEY" http://localhost:8000/mcp/list_tables
   
   # Describe a table
   curl -H "X-API-Key: $MCP_API_KEY" http://localhost:8000/mcp/describe/customers
   
   # Natural language query
   curl -X POST "http://localhost:8000/mcp/query" \
     -H "X-API-Key: $MCP_API_KEY" \
     -H "Content-Type: application/json" \
     -d '{"nl_query": "show top 5 customers by total orders"}'
   

Option 2: Local Development

1. Prerequisites:

   • Python 3.11+
   • PostgreSQL or MySQL database

2. Install dependencies:

   Terminal

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   pip install -r requirements.txt
   

3. Set environment variables:

   server.ts

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   export DATABASE_URL="postgresql+asyncpg://user:password@localhost:5432/dbname"
   export MCP_API_KEY="$(openssl rand -hex 32)"
   # or for MySQL:
   # export DATABASE_URL="mysql+pymysql://user:password@localhost:3306/dbname"
   

4. Run the server:

   bash

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   python -m app.server
   

Sample Database

The project includes a sample database with realistic e-commerce data:

• customers: Customer information (10 sample customers)
• orders: Order records (17 sample orders)
• order_items: Individual items within orders
• order_summary: View combining order and customer data

Natural Language Query Examples

The server can understand various types of natural language queries:

# Get all customers
curl -X POST "http://localhost:8000/mcp/query" \
  -H "Content-Type: application/json" \
  -d '{"nl_query": "show all customers"}'

# Count orders by status
curl -X POST "http://localhost:8000/mcp/query" \
  -H "Content-Type: application/json" \
  -d '{"nl_query": "count orders by status"}'

# Top customers by order value
curl -X POST "http://localhost:8000/mcp/query" \
  -H "Content-Type: application/json" \
  -d '{"nl_query": "top 5 customers by total order amount"}'

# Recent orders
curl -X POST "http://localhost:8000/mcp/query" \
  -H "Content-Type: application/json" \
  -d '{"nl_query": "show recent orders from last week"}'

Configuration

Environment Variables

Database Connection Examples

# PostgreSQL
DATABASE_URL=postgresql+asyncpg://user:pass@localhost:5432/mydb

# MySQL
DATABASE_URL=mysql+pymysql://user:pass@localhost:3306/mydb

# PostgreSQL with SSL
DATABASE_URL=postgresql+asyncpg://user:pass@localhost:5432/mydb?sslmode=require

### Database Connection Examples

```bash
# PostgreSQL (local or cloud)
DATABASE_URL=postgresql+asyncpg://user:password@host:5432/dbname

# MySQL (local or cloud)
DATABASE_URL=mysql+aiomysql://user:password@host:3306/dbname

# PostgreSQL with SSL (cloud, e.g. Neon, Supabase, Aiven)
DATABASE_URL=postgresql+asyncpg://user:password@host:5432/dbname?sslmode=require

# MySQL with SSL (cloud, e.g. Aiven, PlanetScale)
DATABASE_URL=mysql+aiomysql://user:password@host:3306/dbname?ssl-mode=REQUIRED

Note:

• For MySQL cloud providers, the ssl-mode parameter in the URL is ignored by the driver, but SSL is always enabled in the MCP server for cloud connections.
• For PostgreSQL, use sslmode=require for cloud DBs. For MySQL, just use the standard URL; SSL is handled automatically.
• If you see errors about ssl-mode or sslmode, check your URL and ensure you are using the correct driver prefix (mysql+aiomysql or postgresql+asyncpg).

Cloud Database Examples

# Neon (PostgreSQL)
DATABASE_URL=postgresql+asyncpg://username:password@ep-xxxxxx-pooler.us-east-2.aws.neon.tech/dbname

# Aiven (MySQL)
DATABASE_URL=mysql+aiomysql://avnadmin:yourpassword@mysql-xxxxxx-username-xxxx.aivencloud.com:11079/defaultdb?ssl-mode=REQUIRED

Docker Usage with Cloud DB

docker run -d \
  -p 8000:8000 \
  -e DATABASE_URL="<your_cloud_database_url>" \
  -e MCP_API_KEY="<your_random_api_key>" \
  souhardyak/mcp-db-server:latest

GitHub Container Registry is also available:

docker login ghcr.io
docker pull ghcr.io/souhar-dya/mcp-db-server:latest
docker run -d \
  -p 8000:8000 \
  -e DATABASE_URL="<your_database_url>" \
  -e MCP_API_KEY="$MCP_API_KEY" \
  ghcr.io/souhar-dya/mcp-db-server:latest

Images are published automatically when a v*.*.* tag is pushed. The workflow also creates the matching GitHub Release. To publish an existing tag such as v1.4.0, open the workflow's Run workflow action and enter 1.4.0. Set the GHCR package visibility to Public in the repository's Packages settings if unauthenticated pulls should be allowed.

Troubleshooting

• If you get connect() got an unexpected keyword argument 'ssl-mode', ignore it: SSL is still enabled.
• For network errors, check firewall and DB credentials.
• For MySQL, always use mysql+aiomysql in the URL for async support.

### PostgreSQL SSL connection note

For PostgreSQL cloud providers, use an asyncpg URL and `sslmode=require`:

```bash
DATABASE_URL=postgresql+asyncpg://user:password@host:5432/dbname?sslmode=require

The server normalizes sslmode=require to the ssl option expected by asyncpg. A temporary PostgreSQL verification was completed successfully against a compatible cloud database using CREATE, INSERT, SELECT, UPDATE, DELETE, and DROP; no test data was retained. Never commit or share a connection URL containing a real password.

API key authentication