Integrations

Runs as a Node.js application, serving as the execution environment for the MCP server
Provides a secure read-only interface to PostgreSQL databases, allowing execution of validated SELECT queries with timeout protection

MCP Postgres Query Server

A Model Context Protocol (MCP) server implementation for querying a PostgreSQL database in read-only mode, designed to work with Claude Desktop and other MCP clients.

Overview

This project implements a Model Context Protocol (MCP) server that provides:

A secure, read-only interface to a PostgreSQL database
Integration with Claude Desktop through the MCP protocol
SQL query validation to ensure only SELECT queries are executed
Query timeout protection (10 seconds)

Prerequisites

Node.js (v14 or later)
npm (comes with Node.js)
PostgreSQL database (connection details provided via command line)

Installation

# Clone the repository
git clone https://github.com/RathodDarshil/mcp-postgres-query-server.git
cd mcp-postgres-query-server

# Install dependencies
npm install

# Build the project
npm run build

Connecting to Claude Desktop

You can configure Claude Desktop to automatically launch and connect to the MCP server:

Access the Claude Desktop configuration file:
- Open Claude Desktop
- Go to Settings > Developer > Edit Config
- This will open the configuration file in your default text editor
Add the postgres-query-server to the mcpServers section of your claude_desktop_config.json:

{
    "mcpServers": {
        "postgres-query": {
            "command": "node",
            "args": [
                "/path/to/your/mcp-postgres-query-server/dist/index.js",
                "postgresql://username:password@hostname:port/database"
            ]
        }
    }
}

Replace /path/to/your/ with the actual path to your project directory.
Replace the PostgreSQL connection string with your actual database credentials.
Save the file and restart Claude Desktop. The MCP server should now appear in the MCP server selection dropdown in Settings.

Example Configuration

Here's a complete example of a configuration file with postgres-query:

{
    "mcpServers": {
        "postgres-query": {
            "command": "node",
            "args": [
                "/Users/darshilrathod/mcp-servers/mcp-postgres-query-server/dist/index.js",
                "postgresql://user:password@localhost:5432/mydatabase"
            ]
        }
    }
}

Updating Configuration

To update your Claude Desktop configuration:

Open Claude Desktop
Go to Settings > Developer > Edit Config
Make your changes to the configuration file
Save the file
Restart Claude Desktop for the changes to take effect
If you've updated the MCP server code, make sure to rebuild it with npm run build before restarting

Features

Read-Only Database Access: Only SELECT queries are permitted for security
Query Validation: Prevents potentially harmful SQL operations
Timeout Protection: Queries running longer than 10 seconds are automatically terminated
MCP Protocol Support: Complete implementation of the Model Context Protocol
JSON Response Formatting: Query results are returned in structured JSON format

API

Tools

query-postgres

Executes a read-only SQL query against the configured PostgreSQL database.

Parameters:

query (string): A SQL SELECT query to execute

Response:

JSON object containing:
- rows: The result set rows
- rowCount: Number of rows returned
- fields: Column metadata

Example:

query-postgres: SELECT * FROM users LIMIT 5

Development

The main server implementation is in src/index.ts. Key components:

PostgreSQL connection pool setup
Query validation logic
MCP server configuration
Tool and resource definitions

To modify the server's behavior, you can:

Edit the query validation logic in isReadOnlyQuery()
Add additional tools or resources to the MCP server
Modify the query timeout duration (currently 10 seconds)

Security Considerations

The server validates all queries to ensure they are read-only
Connection to the database uses SSL
Query timeout prevents resource exhaustion
No write operations are permitted
Database credentials are passed directly via command line arguments, not stored in files

License

ISC

Contributing

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

This server cannot be installed

-

security - not tested

F

license - not found

-

quality - not tested

A secure Model Context Protocol server that allows Claude to execute read-only SQL queries against a PostgreSQL database, enabling natural language interaction with database data.

PostgreSQL Query MCP Server