Add OAuth auth to FastAPI + FastMCP (Scalekit)

When to use this skill vs the FastMCP skill

Use THIS skill when:

• You need custom FastAPI middleware, routes, or dependency injection alongside MCP tools
• You're adding MCP to an existing FastAPI application
• You need more control over request handling than FastMCP's built-in ScalekitProvider offers

Use the mcp-auth-fastmcp-scalekit skill instead when:

• You're building a standalone MCP server and don't need FastAPI-specific features
• You want the simplest possible setup (5-line auth config)

Critical wiring: how FastMCP mounts into FastAPI

FastMCP is NOT run standalone. It is mounted inside FastAPI:

mcp_app = mcp.http_app(path="/")
app = FastAPI(lifespan=mcp_app.lifespan)  # lifespan MUST come from mcp_app
# ... add middleware and routes BEFORE mounting ...
app.mount("/", mcp_app)  # MUST be last