pg-mcp

MCP (Model Context Protocol) server for PostgreSQL databases. Enables Claude and other AI assistants to query databases, inspect schemas, and get DDL - with built-in read-only protection.

Features

• pg_connect - Connect to PostgreSQL databases (URL or individual params)
• pg_disconnect - Disconnect from databases
• pg_query - Execute SQL queries
• pg_list_schemas - List all schemas
• pg_get_ddl - Get complete DDL (tables, indexes, constraints, foreign keys, views)
• Read-only mode - Blocks INSERT, UPDATE, DELETE, and DDL operations (enabled by default)

Installation

Using npx (recommended)

npx pg-mcp

Global install

npm install -g pg-mcp

From source

git clone https://github.com/shedyhs/pg-mcp
cd pg-mcp
npm install
npm run build

Configuration

Claude Desktop

Add to your claude_desktop_config.json:

{
  "mcpServers": {
    "postgres": {
      "command": "npx",
      "args": ["pg-mcp"]
    }
  }
}

Claude Code

Add to your .claude/settings.json:

{
  "mcpServers": {
    "postgres": {
      "command": "npx",
      "args": ["pg-mcp"]
    }
  }
}

With environment variable

You can set DATABASE_URL to auto-connect:

{
  "mcpServers": {
    "postgres": {
      "command": "npx",
      "args": ["pg-mcp"],
      "env": {
        "DATABASE_URL": "postgres://user:pass@localhost:5432/mydb"
      }
    }
  }
}

Usage

Connect to database

pg_connect({
  connectionId: "main",
  url: "postgres://user:pass@localhost:5432/mydb"
})

Or with individual parameters:

pg_connect({
  connectionId: "main",
  host: "localhost",
  port: 5432,
  database: "mydb",
  user: "postgres",
  password: "secret"
})

Read-only mode

By default, connections are read-only. This blocks:

• DML: INSERT, UPDATE, DELETE, TRUNCATE, MERGE
• DDL: CREATE, ALTER, DROP, RENAME
• DCL: GRANT, REVOKE

To disable (use with caution):

pg_connect({
  connectionId: "main",
  url: "postgres://...",
  readOnly: false
})

Query examples

-- List tables
SELECT table_name FROM information_schema.tables WHERE table_schema = 'public';

-- Query data
SELECT * FROM users LIMIT 10;

-- Get table structure
pg_get_ddl({ connectionId: "main", schema: "public" })

Tools

Tool	Description
pg_connect	Connect to a PostgreSQL database
pg_disconnect	Disconnect from a database
pg_query	Execute a SQL query
pg_list_schemas	List all schemas in the database
pg_get_ddl	Get complete DDL for the database

License

MIT