mcp-examples

Reference implementations of MCP servers using:

• FastAPI + fastapi-mcp
• FastMCP (STDIO and HTTP transports)
• FastMCP + feedparser for RSS/Atom querying

These examples are intentionally small and are useful as starter templates.

Repository layout

.
├── .env-template
├── fastapi-mcp/
│   └── fastapi-mcp-calculator.py
├── fastmcp/
│   ├── fastmcp-calculator.py
│   └── fastmcp-calculator-v2.py
├── mcp-feed-parser/
│   └── mcp-feed-parser.py
└── requirements.txt

Prerequisites

• Python 3.10+
• uv (Python package manager and runner)
• Node.js (optional, only for MCP Inspector)

Environment setup

Create a local environment file from the template:

cp .env-template .env

Then edit .env with your local values.

The provided .env-template includes starter defaults. The current examples do not require environment variables unless you wire these values into the scripts.

Install dependencies (uv)

uv venv
source .venv/bin/activate
uv pip install -r requirements.txt

Examples

1) FastAPI + FastAPI-MCP calculator

File: fastapi-mcp/fastapi-mcp-calculator.py

What it demonstrates:

• Building a basic FastAPI calculator API (add, subtract, multiply, divide)
• Mounting MCP over the same app using FastApiMCP(app).mount_http()
• Running with Uvicorn on 0.0.0.0:8000

Run:

uv run python fastapi-mcp/fastapi-mcp-calculator.py

2) FastMCP calculator (STDIO transport)

File: fastmcp/fastmcp-calculator.py

What it demonstrates:

• Registering tools with @mcp.tool()
• Naming/tagging tools for better discoverability
• Running an MCP server over STDIO (useful for local client subprocess integration)

Run:

uv run python fastmcp/fastmcp-calculator.py

3) FastMCP calculator (HTTP transport)

File: fastmcp/fastmcp-calculator-v2.py

What it demonstrates:

• The same calculator tools as above
• Running FastMCP with HTTP transport on localhost:8080

Run:

uv run python fastmcp/fastmcp-calculator-v2.py

4) FastMCP feed parser

File: mcp-feed-parser/mcp-feed-parser.py

What it demonstrates:

• Querying RSS/Atom feeds using feedparser
• Reusing a shared feed-search helper
• Exposing feed lookup as MCP tools:
  • fcc_news_parser
  • fcc_youtube_parser
  • fcc_secret_message

Run:

uv run python mcp-feed-parser/mcp-feed-parser.py

Inspecting/debugging with MCP Inspector

The MCP Inspector is the easiest way to test tools and inspect schemas.

npx @modelcontextprotocol/inspector <your-server-command>

For example (local Python server):

npx @modelcontextprotocol/inspector uv run python fastmcp/fastmcp-calculator.py

Notes

• The FastAPI sample filename is intentionally kept as-is (calcularor) to match repository history.
• Calculator division tools guard against division by zero.
• The feed parser returns a fallback message when no matches are found.

References:

• MCP documentation and specification: https://modelcontextprotocol.io/
• MCP Inspector guide: https://modelcontextprotocol.io/docs/tools/inspector
• @modelcontextprotocol/inspector package: https://www.npmjs.com/package/@modelcontextprotocol/inspector
• FastMCP docs: https://gofastmcp.com/getting-started/welcome
• FastMCP repository: https://github.com/prefecthq/fastmcp
• FastAPI-MCP docs: https://fastapi-mcp.tadata.com/
• FastAPI docs: https://fastapi.tiangolo.com/
• feedparser docs: https://feedparser.readthedocs.io/en/latest/

Original reference video

• https://youtu.be/DosHnyq78xY?si=V4DSGMHX4kE3BYMh