PostgreSQL MCP Server

A PostgreSQL MCP server implementation using the Model Context Protocol (MCP) Python SDK- an open protocol that enables seamless integration between LLM applications and external data sources. This server allows AI agents to interact with PostgreSQL databases through a standardized interface.

Features

List database schemas
List tables within schemas
Describe table structures
List table constraints and relationships
Get foreign key information
Execute SQL queries

Prerequisites

Python 3.x
PostgreSQL database server
Access to a PostgreSQL database

Installation

Clone this repository:

git clone <repository-url>
cd mcp-postgres

Create and activate a virtual environment (recommended):

python -m venv venv
source venv/bin/activate  # On Windows, use: venv\Scripts\activate

Install dependencies:

pip install -r requirements.txt

Usage

Start the MCP server by providing your PostgreSQL connection string:

python postgres_server.py "postgresql://username:password@host:port/database"

The server provides the following tools:

query: Execute SQL queries against the database
list_schemas: List all available schemas
list_tables: List all tables in a specific schema
describe_table: Get detailed information about a table's structure
get_foreign_keys: Get foreign key relationships for a table
find_relationships: Discover both explicit and implied relationships for a table

Configuration with mcp.json

To integrate this server with MCP-compatible tools (like Cursor), add it to your ~/.cursor/mcp.json:

{
  "servers": {
    "postgres": {
      "command": "/path/to/venv/bin/python",
      "args": [
        "/path/to/postgres_server.py",
        "postgresql://username:password@host:5432/database?ssl=true"
      ]
    }
  }
}

Replace:

/path/to/venv with your virtual environment path
/path/to/postgres_server.py with the absolute path to the server script
Connection string with your PostgreSQL database credentials

Note: Make sure to properly secure your mcp.json file as it contains sensitive database credentials.

Security

Never expose sensitive database credentials in your code
Use environment variables or secure configuration files for database connection strings
Consider using connection pooling for better resource management
Implement proper access controls and user authentication

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

Related Projects

License

MIT License

Permission is hereby granted, free of charge, to any person obtaining a copyof this software and associated documentation files (the "Software"), to dealin the Software without restriction, including without limitation the rightsto use, copy, modify, merge, publish, distribute, sublicense, and/or sellcopies of the Software, and to permit persons to whom the Software isfurnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in allcopies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS ORIMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THEAUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHERLIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THESOFTWARE.

PostgreSQL MCP Server