MCP Manager Example (FastAPI)

This example shows how to use MCPServerManager to keep MCP server lifecycle management in a single task inside a FastAPI app with the Streamable HTTP transport.

Run the MCP server (Streamable HTTP)

uv run python examples/mcp/manager_example/mcp_server.py

The server listens at http://localhost:8000/mcp by default.

You can override the host/port with:

export STREAMABLE_HTTP_HOST=127.0.0.1
export STREAMABLE_HTTP_PORT=8000

This example also configures an inactive MCP server at http://localhost:8001/mcp to demonstrate how the manager drops failed servers. You can override it with:

export INACTIVE_MCP_SERVER_URL=http://localhost:8001/mcp

Run the FastAPI app

uv run python examples/mcp/manager_example/app.py

The app listens at http://127.0.0.1:9001.

Toggle MCP manager usage

By default, the app uses MCPServerManager. To disable it:

export USE_MCP_MANAGER=0

Try the endpoints

curl http://127.0.0.1:9001/health
curl http://127.0.0.1:9001/tools
curl -X POST http://127.0.0.1:9001/add \
  -H 'Content-Type: application/json' \
  -d '{"a": 2, "b": 3}'

Reconnect failed MCP servers (manager must be enabled):

curl -X POST http://127.0.0.1:9001/reconnect \
  -H 'Content-Type: application/json' \
  -d '{"failed_only": true}'

To use /run, set OPENAI_API_KEY:

export OPENAI_API_KEY=...
curl -X POST http://127.0.0.1:9001/run \
  -H 'Content-Type: application/json' \
  -d '{"input": "Add 4 and 9."}'