qQsss777/mcp-postgres

mcp-logs

POC (Proof of Concept) to query and analyze application logs stored in PostgreSQL (with TimescaleDB), and expose tools via an MCP server usable in Cursor or Claude Desktop.

Objectives

• Storage of logs in a PostgreSQL/TimescaleDB database
• MCP Tool to query the database (e.g., list tables)
• Scripts to initialize the schema and test data

Project Structure

• docker-compose.yml : PostgreSQL (TimescaleDB) service ready to use
• scripts/ :
  • Dockerfile and conf/ for PostgreSQL configuration
  • sql/01-schema.sql : creation of the logs table and TimescaleDB hypertable
  • sql/02-inserts.sql : test data
• src/ :
  • index.js : MCP server (Model Context Protocol)
  • tools/tableTool.js : function to list tables and describe them
  • tools/searchTool.js : function to search in tables

Prerequisites

• Docker and Docker Compose
• Node.js 18+
• MCP client (e.g., Claude Desktop, Cursor)

Quick Start

1. Create environment file

Create a .env file in the project root with the following PostgreSQL variables: e.g.:

POSTGRES_USER=postgres
POSTGRES_PASSWORD=postgres
POSTGRES_DB=logs
POSTGRES_PORT=5432
POSTGRES_HOST=127.0.0.1

2. Launch PostgreSQL (TimescaleDB)

docker-compose up -d

The service exposes PostgreSQL on 127.0.0.1:5432 with your .env variables, e.g:

• user: postgres
• password: postgres
• database: logs

3. Initialize schema and data (if your image/entrypoint doesn't do it automatically)

Depending on your Docker configuration, the sql/01-schema.sql and sql/02-inserts.sql files may be executed automatically. Otherwise, connect and execute them manually.

4. Launch the MCP server

To test if everything works, launch the MCP server.

node .

The MCP server exposes a tool to list database tables and search in tables.

Usage

From an MCP client (Claude Desktop)

• Configure the MCP client according to the client documentation, for example:

{
  "mcpServers": {
    "postgresql": {
      "type": "stdio",
      "command": "node",
      "args": ["LOCAL_PATH/mpc-logs"]
    }
  }
}

• Ask for the latest error logs from last week and make a summary.

Example result

License

MIT