### Install the LangGraph Python SDK
### Wire CopilotKit middleware into your graph
For `useHumanInTheLoop` tool-based HITL, the tool is defined entirely on
the frontend and forwarded to the agent. `CopilotKitMiddleware` is what
forwards it — drop it into your `create_agent` call.
For the `useInterrupt` graph-paused pattern, you'll also use LangGraph's
native `interrupt(...)` primitive inside a graph node — no extra
CopilotKit setup beyond the middleware above.