Postgres MCP Server

A Model Context Protocol (MCP) server that provides secure database access to PostgreSQL through Kysely ORM. This server enables Claude Desktop to interact with PostgreSQL databases using natural language.

📚 Documentation

Full documentation is available at: caleb-mabry.github.io/postgres-mcp

Quick Links

• Getting Started
• Claude Desktop Setup
• HTTP Server Setup
• Docker Setup
• Usage Modes

Features

• MCP Tools: Query execution, table listing, schema inspection, and constraint information
• Type Safety: Full TypeScript support with typed inputs/outputs
• Connection Pooling: Configurable connection limits with idle timeout
• Error Handling: Graceful error messages for connection and query issues
• Security: Parameterized queries to prevent SQL injection

Quick Start

For Claude Desktop Users

See the 📖 Claude Desktop Setup Guide for complete instructions.

For HTTP/API Usage

See the 📖 HTTP Server Setup Guide for complete instructions.

For Docker

See the 📖 Docker Setup Guide for complete instructions.

Direct Installation

npx -y @calebmabry/postgres-mcp-server

Configuration

Create a .env file with your database credentials:

DB_HOST=127.0.0.1
DB_PORT=5432
DB_USER=postgres
DB_PASSWORD=your_password_here
DB_NAME=postgres
DB_SSL=true

# HTTP Server mode only (optional)
PORT=3000
ALLOWED_HOSTS=localhost,127.0.0.1

Available Tools

Tool	Description	Required Parameters	Optional Parameters
query	Execute SQL queries with pagination support	sql (string)	pageSize (1-500), offset (number), parameters (array)
describe_table	Get table structure and column details	schema (string), table (string)	-
list_tables	List all tables in a schema	schema (string)	-
list_schemas	List all schemas in the database	-	includeSystemSchemas (boolean)
get_constraints	Get table constraints (PK, FK, etc.)	schema (string), table (string)	-
list_indexes	List indexes for a table or schema	schema (string)	table (string)
list_views	List views in a schema	schema (string)	-
list_functions	List functions and procedures	schema (string)	-
explain_query	Get query execution plan	sql (string)	analyze (boolean), format (text/json/xml/yaml)
get_table_stats	Get table size and statistics	schema (string)	table (string)

Key Features

• Pagination: Query tool supports up to 500 rows per page with automatic LIMIT/OFFSET handling
• Security: Parameterized queries prevent SQL injection, READ_ONLY mode by default
• Type Safety: Full TypeScript support with Zod schema validation

Client Configuration

The postgres-mcp-server works with any MCP-compatible client. See configuration examples below:

Claude Desktop

Add to claude_desktop_config.json:

{
  "mcpServers": {
    "postgres-mcp-server": {
      "command": "npx",
      "args": ["-y", "@calebmabry/postgres-mcp-server"],
      "env": {
        "DB_HOST": "127.0.0.1",
        "DB_PORT": "5432",
        "DB_USER": "postgres",
        "DB_PASSWORD": "your_password_here",
        "DB_NAME": "your_database_name",
        "DB_SSL": "false",
        "READ_ONLY": "true"
      }
    }
  }
}

Config locations:

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

See claude_config_example.json for a full example.

Cline (VS Code)

Add to .cline/mcp_settings.json:

{
  "mcpServers": {
    "postgres-mcp-server": {
      "command": "npx",
      "args": ["-y", "@calebmabry/postgres-mcp-server"],
      "env": {
        "DB_HOST": "localhost",
        "DB_NAME": "your_database",
        "DB_USER": "postgres",
        "DB_PASSWORD": "your_password"
      }
    }
  }
}

See cline_mcp_settings_example.json for a full example.

Zed Editor

Add to Zed settings (Settings → Context Servers):

{
  "context_servers": {
    "postgres-mcp-server": {
      "command": {
        "path": "npx",
        "args": ["-y", "@calebmabry/postgres-mcp-server"]
      },
      "settings": {
        "DB_HOST": "localhost",
        "DB_NAME": "your_database",
        "DB_USER": "postgres",
        "DB_PASSWORD": "your_password"
      }
    }
  }
}

See zed_settings_example.json for a full example.

Docker

Use the included Dockerfile or docker-compose.yml:

docker-compose up -d

See docker-compose.example.yml for a full example.

Development

# Clone and install dependencies
git clone https://github.com/caleb-mabry/postgres-mcp.git
cd postgres-mcp-server
npm install

# Run in development mode with hot reload
npm run dev

# Build for production
npm run build

# Run tests
npm run test

# Run specific test suites
npm run test:unit
npm run test:integration

Environment Variables

Variable	Default	Description
DB_HOST	127.0.0.1	PostgreSQL host
DB_PORT	5432	PostgreSQL port
DB_USER	postgres	Database user
DB_PASSWORD	required	Database password
DB_NAME	postgres	Database name
DB_SSL	false	Enable SSL connection (set to false for local dev)
READ_ONLY	true	Restrict to SELECT/WITH/EXPLAIN queries
QUERY_TIMEOUT	30000	Query timeout in milliseconds
MAX_PAGE_SIZE	500	Maximum rows per page
DEFAULT_PAGE_SIZE	100	Default page size when not specified
PORT	3000	HTTP server port (HTTP mode only)
ALLOWED_HOSTS	none	Comma-separated allowed hosts (HTTP mode only). Example: localhost,127.0.0.1,example.com
MODE	stdio	Server mode in Docker: stdio or http

For detailed documentation on all features and setup options, visit caleb-mabry.github.io/postgres-mcp.

License

ISC