@marcelo-ochoa/server-postgres

PostgreSQL

A Model Context Protocol server that provides read-only access to PostgreSQL databases. This server enables LLMs to inspect database schemas and execute read-only queries.

Components

Tools

• pg-query

  • Execute read-only SQL queries against the connected database
  • Input: sql (string): The SQL query to execute
  • All queries are executed within a READ ONLY transaction

• pg-stats

  • Get statistics for a specific table
  • Input: name (string): The name of the table to get statistics for

• pg-explain

  • Explain Plan for a given SQL query
  • Input: sql (string): The SQL query to explain

• pg-connect

  • Connect to a PostgreSQL database
  • Inputs:
    • connectionString (string): The PostgreSQL connection string without credentials (e.g. postgresql://host:port/dbname or host:port/dbname)
    • user (string): The PostgreSQL username
    • password (string): The PostgreSQL password

• pg-awr

  • Generate a PostgreSQL performance report similar to Oracle AWR. Includes database statistics, top queries (requires pg_stat_statements extension), table/index statistics, connection info, and optimization recommendations.

Resources

The server provides schema information for each table in the database:

• Table Schemas (postgres://<dbname>/<table>/schema)
  • JSON schema information for each table
  • Includes column names and data types
  • Automatically discovered from database metadata

Change Log

See Change Log for the history of changes.

Configuration

Authentication

The PostgreSQL server uses environment variables for secure credential management:

• PG_USER: PostgreSQL username (required)
• PG_PASSWORD: PostgreSQL password (required)

The connection string should contain only the host, port, and database information (without embedded credentials).

Supported connection string formats:

• postgresql://host:port/dbname
• host:port/dbname

Usage with Claude Desktop

To use this server with the Claude Desktop app, add the following configuration to the "mcpServers" section of your claude_desktop_config.json:

Docker

• When running Docker on macOS, use host.docker.internal if the PostgreSQL server is running on the host network (e.g., localhost)
• Credentials are passed via environment variables PG_USER and PG_PASSWORD

{
  "mcpServers": {
    "postgres": {
      "command": "docker",
      "args": [
        "run", 
        "-i", 
        "--rm",
        "-e", "PG_USER=myuser",
        "-e", "PG_PASSWORD=mypassword",
        "mochoa/mcp-postgres", 
        "postgresql://host.docker.internal:5432/mydb"
      ]
    }
  }
}

NPX

{
  "mcpServers": {
    "postgres": {
      "command": "npx",
      "args": [
        "-y",
        "@marcelo-ochoa/server-postgres",
        "postgresql://localhost:5432/mydb"
      ],
      "env": {
        "PG_USER": "myuser",
        "PG_PASSWORD": "mypassword"
      }
    }
  }
}

Replace /mydb with your database name.

Note: Replace the following placeholders with your actual values:

• myuser and mypassword with your PostgreSQL credentials
• localhost:5432 with your PostgreSQL server host and port
• mydb with your database name

Usage with VS Code

For quick installation, use one of the one-click install buttons below...

For manual installation, add the following JSON block to your User Settings (JSON) file in VS Code. You can do this by pressing Ctrl + Shift + P and typing Preferences: Open User Settings (JSON).

Optionally, you can add it to a file called .vscode/mcp.json in your workspace. This will allow you to share the configuration with others.

Note that the mcp key is not needed in the .vscode/mcp.json file.

Docker

Note: When using Docker and connecting to a PostgreSQL server on your host machine, use host.docker.internal instead of localhost in the connection URL.

{
  "mcp": {
    "inputs": [
      {
        "type": "promptString",
        "id": "pg_url",
        "description": "PostgreSQL URL (e.g. postgresql://host.docker.internal:5432/mydb)"
      },
      {
        "type": "promptString",
        "id": "pg_user",
        "description": "PostgreSQL username"
      },
      {
        "type": "promptString",
        "id": "pg_password",
        "description": "PostgreSQL password",
        "password": true
      }
    ],
    "servers": {
      "postgres": {
        "command": "docker",
        "args": [
          "run",
          "-i",
          "--rm",
          "-e", "PG_USER=${input:pg_user}",
          "-e", "PG_PASSWORD=${input:pg_password}",
          "mochoa/mcp-postgres",
          "${input:pg_url}"
        ]
      }
    }
  }
}

NPX

{
  "mcp": {
    "inputs": [
      {
        "type": "promptString",
        "id": "pg_url",
        "description": "PostgreSQL URL (e.g. postgresql://localhost:5432/mydb)"
      },
      {
        "type": "promptString",
        "id": "pg_user",
        "description": "PostgreSQL username"
      },
      {
        "type": "promptString",
        "id": "pg_password",
        "description": "PostgreSQL password",
        "password": true
      }
    ],
    "servers": {
      "postgres": {
        "command": "npx",
        "args": [
          "-y",
          "@marcelo-ochoa/server-postgres",
          "${input:pg_url}"
        ],
        "env": {
          "PG_USER": "${input:pg_user}",
          "PG_PASSWORD": "${input:pg_password}"
        }
      }
    }
  }
}

PostgreSQL AWR in action

See PostgreSQL AWR in action for an example of a performance report generated by the pg-awr tool for a production Moodle database, highlighting critical performance issues and optimization opportunities.

Building

Docker:

docker build -t mochoa/mcp-postgres -f src/postgres/Dockerfile .

Sources

As usual the code of this extension is at GitHub, feel free to suggest changes and make contributions, note that I am a beginner developer of React and TypeScript so contributions to make this UI better are welcome.

License

This MCP server is licensed under the MIT License. This means you are free to use, modify, and distribute the software, subject to the terms and conditions of the MIT License. For more details, please see the LICENSE file in the project repository.