Streaming UI integration

The stream() API yields events with backpressure. Wire it into a WebSocket / SSE / Server-Sent Events handler:


from fastapi import FastAPI
from sse_starlette.sse import EventSourceResponse
from loomflow import Agent
 
app = FastAPI()
agent = Agent("...", model="claude-opus-4-7")
 
@app.get("/chat")
async def chat(prompt: str):
    async def event_source():
        async for event in agent.stream(prompt):
            yield {
                "event": event.kind.value,
                "data": event.model_dump_json(),
            }
    return EventSourceResponse(event_source())

Breaking out of the iteration cancels the producer cleanly. Even if a tool call is mid-flight, it’ll be cancelled within the cancel scope.