joybindroo/pyMCP

pyMCP

pyMCP is a Python-based Model Context Protocol (MCP) server that allows AI tools like Claude Desktop, Visual Studio Code (GitHub Copilot) to safely interact with SQL databases in a read-only manner.

It includes two server scripts:

• postgres_mcp_server.py – Optimized for PostgreSQL only
• db_mcp_server.py – Multi-database support for PostgreSQL, MySQL, and SQLite

Features

• ✅ Read-only SQL enforcement – Blocks unsafe commands (DELETE, DROP, UPDATE, INSERT)
• ✅ SQL injection prevention – Uses parameterized queries
• ✅ Automatic result limits – Prevents large/unbounded output
• ✅ Schema discovery – List tables, columns, and database structure
• ✅ Multi-database support (db_mcp_server.py) – Connects to:
  • PostgreSQL
  • MySQL
  • SQLite

1. Installation

Requirements

• Python 3.8+
• For MySQL support: mysqlclient or PyMySQL
• For PostgreSQL support: psycopg2
• For SQLite support: built-in with Python
• Access to the target database (local or remote)

Setup Steps

# Clone the repository
git clone https://github.com/joybindroo/postpymcp.git
cd pyMCP

# Create virtual environment
python -m venv venv
source venv/bin/activate       # On Windows: venv\Scripts\activate

# Install dependencies
pip install -r requirements.txt

2. Usage

A. PostgreSQL-only Server

python postgres_mcp_server.py "postgresql://username:password@localhost:5432/database_name"

• Using environment variable:

export DATABASE_URL="postgresql://username:password@localhost:5432/database_name"
python postgres_mcp_server.py

B. Multi-Database Server (PostgreSQL, MySQL, SQLite)

# PostgreSQL
python db_mcp_server.py "postgresql://username:password@localhost:5432/database_name"

# MySQL
python db_mcp_server.py "mysql://username:password@localhost:3306/database_name"

# SQLite (local file)
python db_mcp_server.py "sqlite:///path/to/database.db"

3. Integration with Claude Desktop

1. Locate config file:

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

2. Add MCP server entry:

{
  "mcpServers": {
    "postgres": {
      "command": "python",
      "args": ["/path/to/postgres_mcp_server.py", "postgresql://username:password@localhost:5432/dbname"],
      "env": { "PATH": "/path/to/venv/bin" }
    },
    "multi_db": {
      "command": "python",
      "args": ["/path/to/db_mcp_server.py", "sqlite:///path/to/database.db"],
      "env": { "PATH": "/path/to/venv/bin" }
    }
  }
}

3. Restart Claude Desktop for changes to take effect.

4. Using with Visual Studio Code

• Open the pymcp folder in VS Code
• Ensure Python extension is installed
• Use the integrated terminal to:
  • Start Postgres-only MCP server
  • Start pyMCP server
• Use VS Code Copilot Chat to talk with your db.

5. Using with GitHub Copilot

• Copilot can help:
  • Write custom safe SQL queries
  • Explore schema interactively

6. Example Queries

• SQL:

  SELECT * FROM customers LIMIT 10;
  

• Natural language in Claude/Copilot:
  • "List all tables in the database"
  • "Show me the first 5 rows from the orders table"
  • "Describe the columns in the products table"

7. Troubleshooting

• Ensure database is running and accessible
• Check requirements.txt dependencies are installed
• Use correct connection string syntax for your DB
• If permission errors occur, check script execute permissions:

  chmod +x postgres_mcp_server.py db_mcp_server.py