mcp-postgres-duwenji 1.2.34

MCP server for PostgreSQL database operations

PostgreSQL MCP Server

A Model Context Protocol (MCP) server for PostgreSQL database operations. Provides AI assistants with standardized CRUD operations and database management capabilities.

Status: ✅ COMPLETED - Fully implemented, tested, and published to PyPI

Features

• CRUD Operations: Create, read, update, and delete entities
• Dynamic Table Support: Work with any table without pre-configuration
• Secure Connections: Environment variable-based configuration with validation
• Parameterized Queries: SQL injection protection
• Table Management: Create, alter, and drop tables
• Schema Information: Detailed table schemas and database metadata
• Comprehensive Testing: Unit, integration, and Docker tests

Available Tools

CRUD Operations

• create_entity: Insert new rows into tables
• read_entity: Query tables with optional conditions
• update_entity: Update existing rows based on conditions
• delete_entity: Remove rows from tables
• execute_sql_query: Execute arbitrary SQL queries and return results

Table Management Operations

• create_table: Create new tables with specified schema
• alter_table: Modify existing table structures
• drop_table: Remove tables from database

Schema Operations

• get_tables: Get list of all tables in the database
• get_table_schema: Get detailed schema information for a specific table
• get_database_info: Get database metadata and version information

Available Resources

Database Resources

• database://tables: List of all tables in the database
• database://info: Database metadata and version information
• database://connection: Database connection parameters (host, port, database, username, password, etc.)
• database://schema/{table_name}: Schema information for specific tables

Quick Start

Prerequisites

• Python 3.10 or higher
• PostgreSQL database (version 12 or higher)
• uv package manager (latest version)

Installation

1. Configure your MCP client (e.g., Claude Desktop): Add the server configuration to your MCP client settings using uvx:

   Claude Desktop Configuration Example:

   {
     "mcpServers": {
       "postgres-mcp": {
         "command": "uvx",
         "args": ["mcp-postgres-duwenji"],
         "env": {
           "POSTGRES_HOST": "localhost",
           "POSTGRES_PORT": "5432",
           "POSTGRES_DB": "your_database",
           "POSTGRES_USER": "your_username",
           "POSTGRES_PASSWORD": "your_password",
           "POSTGRES_SSL_MODE": "prefer",
           "MCP_LOG_LEVEL": "INFO",
           "MCP_PROTOCOL_DEBUG": "true",
           "MCP_LOG_DIR": "C:\\Logs\\mcp-postgres"
         }
       }
     }
   }
   

   Docker Automatic Setup Configuration:

   For automatic PostgreSQL Docker container setup, use the following configuration:

   {
     "mcpServers": {
       "postgres-mcp": {
         "disabled": false,
         "timeout": 60,
         "type": "stdio",
         "command": "uvx",
         "args": ["mcp-postgres-duwenji"],
         "env": {
           "MCP_DOCKER_AUTO_SETUP": "true",
           "MCP_DOCKER_IMAGE": "postgres:16",
           "MCP_DOCKER_CONTAINER_NAME": "mcp-postgres-auto",
           "MCP_DOCKER_PORT": "5432",
           "MCP_DOCKER_DATA_VOLUME": "mcp_postgres_data",
           "MCP_DOCKER_PASSWORD": "postgres",
           "MCP_DOCKER_DATABASE": "mcp-postgres-db",
           "MCP_DOCKER_USERNAME": "postgres",
           "MCP_DOCKER_MAX_WAIT_TIME": "30",
           "MCP_LOG_LEVEL": "INFO",
           "MCP_PROTOCOL_DEBUG": "true",
           "MCP_LOG_DIR": "C:\\Logs\\mcp-postgres"
         }
       }
     }
   }
   

   This configuration will automatically:

   • Start a PostgreSQL Docker container when the MCP server starts
   • Use the specified Docker image (postgres:16)
   • Create a persistent data volume for data storage
   • Set up the database with the specified credentials
   • Enable external access (listen on all interfaces)
   • Enable debug logging for troubleshooting

   For detailed Docker setup instructions, see Docker Auto Setup Guide.

External Program Access

When using Docker auto-setup, the PostgreSQL container is configured to allow external connections:

• Listen address: * (all interfaces)
• Port: Configurable via MCP_DOCKER_PORT (default: 5432)
• Authentication: Password-based authentication

External Python programs can use the connection information from the database://connection resource to connect directly to the PostgreSQL database.

Configuration

Environment Variables

The PostgreSQL MCP Server supports the following environment variables for configuration:

Database Connection Variables

• POSTGRES_HOST: PostgreSQL server hostname (default: localhost)
• POSTGRES_PORT: PostgreSQL server port (default: 5432)
• POSTGRES_DB: Database name (required)
• POSTGRES_USER: Database username (required)
• POSTGRES_PASSWORD: Database password (required)
• POSTGRES_SSL_MODE: SSL mode (default: prefer)

Docker Auto-Setup Variables

• MCP_DOCKER_AUTO_SETUP: Enable automatic Docker setup (true/false, default: false)
• MCP_DOCKER_IMAGE: PostgreSQL Docker image (default: postgres:16)
• MCP_DOCKER_CONTAINER_NAME: Docker container name (default: mcp-postgres-auto)
• MCP_DOCKER_PORT: Docker container port (default: 5432)
• MCP_DOCKER_DATA_VOLUME: Data volume name (default: mcp_postgres_data)
• MCP_DOCKER_PASSWORD: Database password for Docker setup (default: postgres)
• MCP_DOCKER_DATABASE: Database name for Docker setup (default: mcp-postgres-db)
• MCP_DOCKER_USERNAME: Database username for Docker setup (default: postgres)
• MCP_DOCKER_MAX_WAIT_TIME: Maximum wait time for container startup in seconds (default: 30)

Performance Monitoring Variables

• MCP_SLOW_QUERY_THRESHOLD_MS: Slow query threshold in milliseconds (default: 1000)
• MCP_ENABLE_AUTO_EXPLAIN: Enable auto_explain extension for query plan logging (true/false, default: true)

Logging and Debug Variables

• MCP_LOG_LEVEL: Log level (DEBUG, INFO, WARNING, ERROR, CRITICAL, default: INFO)
• MCP_PROTOCOL_DEBUG: Enable MCP protocol debug logging (true/false, default: false)

Environment Variable Usage Examples

Using .env File

Create a .env file in your project directory:

# Database Connection
POSTGRES_HOST=localhost
POSTGRES_PORT=5432
POSTGRES_DB=my_database
POSTGRES_USER=my_username
POSTGRES_PASSWORD=my_password
POSTGRES_SSL_MODE=prefer

# Docker Auto-Setup
MCP_DOCKER_AUTO_SETUP=false
MCP_DOCKER_IMAGE=postgres:16
MCP_DOCKER_CONTAINER_NAME=mcp-postgres-auto
MCP_DOCKER_PORT=5432
MCP_DOCKER_DATA_VOLUME=mcp_postgres_data
MCP_DOCKER_PASSWORD=postgres
MCP_DOCKER_DATABASE=mcp-postgres-db
MCP_DOCKER_USERNAME=postgres
MCP_DOCKER_MAX_WAIT_TIME=30

# Performance Monitoring
MCP_SLOW_QUERY_THRESHOLD_MS=1000
MCP_ENABLE_AUTO_EXPLAIN=true

# Logging
MCP_LOG_LEVEL=INFO
MCP_PROTOCOL_DEBUG=false

Using System Environment Variables

Set environment variables directly in your shell:

# Windows PowerShell
$env:POSTGRES_HOST="localhost"
$env:POSTGRES_DB="my_database"
$env:POSTGRES_USER="my_username"
$env:POSTGRES_PASSWORD="my_password"

# Linux/macOS
export POSTGRES_HOST=localhost
export POSTGRES_DB=my_database
export POSTGRES_USER=my_username
export POSTGRES_PASSWORD=my_password

Usage Examples

Once configured, you can use the MCP tools through your AI assistant:

Create a new user:

{
  "table_name": "users",
  "data": {
    "name": "John Doe",
    "email": "[e-mail]",
    "age": 30
  }
}

Read users with conditions:

{
  "table_name": "users",
  "conditions": {
    "age": 30
  },
  "limit": 10
}

Update user information:

{
  "table_name": "users",
  "conditions": {
    "id": 1
  },
  "updates": {
    "email": "[e-mail]"
  }
}

Delete users:

{
  "table_name": "users",
  "conditions": {
    "id": 1
  }
}

Execute custom SQL query:

{
  "query": "SELECT u.name, COUNT(o.id) as order_count FROM users u LEFT JOIN orders o ON u.id = o.user_id GROUP BY u.id, u.name HAVING COUNT(o.id) > 5",
  "limit": 100
}

Execute parameterized SQL query:

{
  "query": "SELECT * FROM users WHERE age > %(min_age)s AND created_at > %(start_date)s",
  "params": {
    "min_age": 18,
    "start_date": "2024-01-01"
  },
  "limit": 50
}

Development

Project Structure

mcp-postgres/
├── src/mcp_postgres_duwenji/     # Main package
├── test/                         # Testing
├── docs/                         # Documentation
├── scripts/                      # Utility scripts
├── memory-bank/                  # Project memory bank
├── pyproject.toml                # Project configuration
└── README.md                     # English README

Running the Server

To run the server directly for testing:

uvx mcp-postgres-duwenji

Direct Execution with Environment Variables:

You can also run the server directly with environment variables:

# Using .env file
uvx mcp-postgres-duwenji

# Using command-line environment variables (Linux/macOS)
POSTGRES_HOST=localhost POSTGRES_DB=my_database POSTGRES_USER=my_username POSTGRES_PASSWORD=my_password uvx mcp-postgres-duwenji

# Using command-line environment variables (Windows PowerShell)
$env:POSTGRES_HOST="localhost"; $env:POSTGRES_DB="my_database"; $env:POSTGRES_USER="my_username"; $env:POSTGRES_PASSWORD="my_password"; uvx mcp-postgres-duwenji

Code Quality Tools

This project uses comprehensive code quality tools:

• Black: Code formatting
• Flake8: Linting and style checking
• MyPy: Static type checking
• Bandit: Security scanning

See docs/code-quality-checks-guide.md and docs/linting-and-type-checking-guide.md for detailed usage instructions.

Adding New Tools

1. Create a new tool definition in src/mcp_postgres_duwenji/tools/
2. Add the tool handler function
3. Register the tool in the appropriate handler function
4. The tool will be automatically available through the MCP interface

Security Considerations

• Always use environment variables for sensitive connection information
• The server uses parameterized queries to prevent SQL injection
• Limit database user permissions to only necessary operations
• Consider using SSL/TLS for database connections in production

License

Apache 2.0