PostgreSQL MCP Server

A Model Context Protocol (MCP) server for PostgreSQL databases. This server provides read-only access to PostgreSQL databases through the MCP protocol, allowing AI assistants to query database schemas and execute SELECT queries safely.

Features

• Schema Exploration: Browse database tables and their column information
• Read-only Queries: Execute SELECT queries safely with transaction isolation
• SSL Support: Handles SSL connections with proper fallback options
• Connection Pooling: Efficient database connection management
• Security: Only allows SELECT queries to prevent data modification

Installation

Install with pip:

pip install postgres-mcp-server

Or run directly with uvx (recommended):

uvx postgres-mcp-server "postgresql://username:password@hostname:port/database"

MCP Client Configuration

To use this server with MCP clients, configure it in your MCP settings:

Claude Desktop

Add to your claude_desktop_config.json:

{
  "mcpServers": {
    "postgres": {
      "command": "uvx",
      "args": [
        "postgres-mcp-server",
        "postgresql://username:password@localhost:5432/database"
      ]
    }
  }
}

Configuration file locations:

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
• Windows: %APPDATA%\Claude\claude_desktop_config.json

Environment Variables

For security, avoid hardcoding credentials:

{
  "mcpServers": {
    "postgres": {
      "command": "uvx",
      "args": [
        "postgres-mcp-server",
        "postgresql://${POSTGRES_USER}:${POSTGRES_PASSWORD}@${POSTGRES_HOST}:${POSTGRES_PORT}/${POSTGRES_DB}"
      ],
      "env": {
        "POSTGRES_HOST": "localhost",
        "POSTGRES_PORT": "5432", 
        "POSTGRES_DB": "database",
        "POSTGRES_USER": "username",
        "POSTGRES_PASSWORD": "password"
      }
    }
  }
}

SSL Configuration Examples

Development (SSL disabled):

{
  "mcpServers": {
    "postgres-dev": {
      "command": "uvx",
      "args": [
        "postgres-mcp-server",
        "postgresql://postgres:password@localhost:5432/mydb?sslmode=disable"
      ]
    }
  }
}

Production (SSL required):

{
  "mcpServers": {
    "postgres-prod": {
      "command": "uvx", 
      "args": [
        "postgres-mcp-server",
        "postgresql://user:pass@prod-db.example.com:5432/mydb?sslmode=require"
      ]
    }
  }
}

Multiple Databases

Configure multiple PostgreSQL connections:

{
  "mcpServers": {
    "postgres-main": {
      "command": "uvx",
      "args": [
        "postgres-mcp-server",
        "postgresql://user:pass@main-db:5432/main_database"
      ]
    },
    "postgres-analytics": {
      "command": "uvx",
      "args": [
        "postgres-mcp-server",
        "postgresql://user:pass@analytics-db:5432/analytics_database" 
      ]
    }
  }
}

SSL Support

The server automatically handles SSL connections with these modes:

• disable: No SSL
• allow: Try non-SSL, then SSL
• prefer: Try SSL, then non-SSL (default)
• require: SSL required
• verify-ca: SSL with CA verification
• verify-full: SSL with full verification

Usage in MCP Clients

Once configured, interact with your PostgreSQL database through natural language:

"What tables are available in the database?" - Lists all tables with their schemas

"Show me the first 10 users" - Executes: SELECT * FROM users LIMIT 10

"Find recent orders with customer info" - Builds complex JOINs automatically

All queries are restricted to SELECT statements for security.

License

MIT