Quiz App MCP server

A Python MCP (Model Context Protocol) server built with FastMCP. Exposes tools to:

• Claude Desktop, locally, over stdio
• claude.ai, remotely, over HTTP (deployed on Render)

Optionally backed by a MySQL database via SQLAlchemy.

Project layout

.
├── server.py           # entry point — branches on RENDER env var (stdio vs HTTP)
├── config.py            # loads .env, exposes shared SQLAlchemy engine
├── tools/
│   ├── __init__.py
│   └── quiz.py           # tool definitions — register(mcp) adds them to a FastMCP instance
├── .env                  # secrets — never commit
├── .env.example
└── requirements.txt

Setup

python -m venv venv
.\venv\Scripts\pip install -r requirements.txt
copy .env.example .env
# fill in .env with real DB credentials (or remove the DB_* lines if unused)

Run locally (stdio)

.\venv\Scripts\python.exe server.py

Or use the MCP inspector to call tools manually:

.\venv\Scripts\python.exe -m mcp dev server.py

Connect to Claude Desktop

Add to %APPDATA%\Claude\claude_desktop_config.json:

{
  "mcpServers": {
    "quizapp": {
      "command": "C:\\path\\to\\project\\venv\\Scripts\\python.exe",
      "args": ["C:\\path\\to\\project\\server.py"]
    }
  }
}

Restart Claude Desktop — tools appear automatically.

Deploy to Render (HTTP, for claude.ai)

1. Push to GitHub (.env is gitignored — never commit it).

2. Create a Render Web Service connected to the repo.

3. Set environment variables in the Render dashboard:

   Variable	Value
   RENDER	true
   DB_HOST	your DB host
   DB_USER	your DB user
   DB_PASSWORD	your DB password
   DB_NAME	your DB name

4. Start command: python server.py

5. In server.py, update BASE_URL under the RENDER branch to your actual Render URL.

6. In claude.ai → Settings → Connectors, add: https://your-app.onrender.com/mcp

No auth is currently configured on the HTTP endpoint — anyone with the URL can call every tool, including DB-backed ones. This was an explicit choice to keep setup simple for now; revisit before exposing anything sensitive (see Security below).

Note

OAuth was removed from the HTTP endpoint for now — we're not using claude.ai against this server's DB/tools yet, so it wasn't worth the extra complexity. Add it back later if needed.

Keep-alive

Render's free tier sleeps after 15 minutes idle, which makes the first request after sleep slow (30–60s) or time out. Mitigations already in place:

• A background thread in server.py pings /health every 10 minutes.
• Add an external monitor (e.g. UptimeRobot) on https://your-app.onrender.com/health every 5 minutes — not on /mcp.

Adding a new tool

Open tools/quiz.py and add a function inside register(mcp):

@mcp.tool()
def my_new_tool(param1: str, param2: int) -> dict:
    """
    One-sentence description of what this tool does.
    The agent reads this docstring to decide when to call the tool.

    Args:
        param1: What this string parameter means.
        param2: What this integer parameter means.
    """
    result = do_something(param1, param2)
    return {"result": result}

No separate registration step — register(mcp) is called for both the stdio and HTTP instances.

Security

• .env is gitignored — never commit it.
• Tools never return raw SQL or expose the DB schema.
• All queries use parameterized SQL (text("... WHERE id = :id"), not string interpolation).
• Any user-supplied table/column name should be checked against an allowlist before use in SQL.
• The Render HTTP endpoint has no authentication — treat it as public. Don't add tools that expose sensitive data or destructive DB operations until auth is added back.