Read-only Database MCP

Minimal TeamSpeak/TypeScript setup that exposes a read-only database Model Context Protocol server and a small UI for managing DB configs, toggling light/dark mode, and viewing usage history.

Prerequisites

• Node 18+
• A PostgreSQL or MySQL/MariaDB database user with read-only permissions

Install

npm install

Run the UI + API

Serves the config/history API and the minimalist UI at http://localhost:4000.

npm run dev

Run the MCP server

The MCP server reads the same saved configs from data/state.json and only exposes read-only tools.

npm run mcp

Tools exposed (over stdio):

• list_tables — input { db: "<configName>" }
• preview_table — input { db: "<configName>", table: "table_name", limit?: number }
• run_select — input { db: "<configName>", sql: "SELECT ..." } (rejects non-SELECT)

Use these tool names when connecting your model/agent to the MCP server.

How to use

1. Start npm run dev and open the UI. Enter DB connection details and click Save config. Set SSL mode to disable, require, or no-verify (self-signed).
   • For MySQL/MariaDB TCP/IP, pick type “MySQL / MariaDB”.
2. Select the saved config in “Use config” to list tables, preview a table, or run a SELECT.
3. Each successful MCP/HTTP call records a history entry (DB name, tables touched, timestamp).
4. In your agent, connect to the MCP server via stdio and call the tools using the saved db name; you only need to pass the friendly name, not the credentials.

Notes

• Configs and history live in data/state.json. Delete that file to reset.
• The server enforces read-only mode with SET SESSION CHARACTERISTICS AS TRANSACTION READ ONLY and rejects non-SELECT queries.
• If your MCP SDK exports different helper names, adjust src/mcp-server.ts registration to match your SDK version.
• Extend src/db.ts to add other engines (MySQL, SQLite) while keeping read-only guards.