pipecat/examples/aws-agentcore/server/server.py

#
# Copyright (c) 2024–2025, Daily
#
# SPDX-License-Identifier: BSD 2-Clause License
#

import argparse
import json
import os
import sys
import uuid
from contextlib import asynccontextmanager
from http import HTTPMethod
from typing import Any, Dict, List, Optional, TypedDict, Union

import boto3
import uvicorn
from botocore.response import StreamingBody
from dotenv import load_dotenv
from fastapi import BackgroundTasks, FastAPI, HTTPException, Request, Response
from fastapi.middleware.cors import CORSMiddleware
from fastapi.responses import RedirectResponse
from loguru import logger
from pipecat_ai_small_webrtc_prebuilt.frontend import SmallWebRTCPrebuiltUI

load_dotenv(override=True)

app = FastAPI()

# Add CORS middleware
app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],  # Add your frontend URL
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)


# In-memory store of active sessions: session_id -> session info
active_sessions: Dict[str, Dict[str, Any]] = {}

# Initialize Bedrock client
bedrock = boto3.client("bedrock-agentcore")

# You can find this inside .bedrock_agentcore.yaml
AGENT_RUNTIME_ARN = os.getenv("AGENT_RUNTIME_ARN")

# Mount the frontend at /
app.mount("/client", SmallWebRTCPrebuiltUI)


@app.get("/", include_in_schema=False)
async def root_redirect():
    return RedirectResponse(url="/client/")


async def post_offer(request: Request, session_id: str):
    """Handle WebRTC offer requests via SmallWebRTCRequestHandler."""

    data = await request.json()
    response = bedrock.invoke_agent_runtime(
        agentRuntimeArn=AGENT_RUNTIME_ARN,
        contentType="application/json",
        payload=json.dumps(data),
        runtimeSessionId=session_id,
    )

    answer_sdp = None

    if "text/event-stream" in response.get("contentType", ""):
        # Handle streaming response
        streaming_body: StreamingBody = response["response"]
        for line in streaming_body.iter_lines(chunk_size=1):
            if line:
                line = line.decode("utf-8")
                if line.startswith("data: "):
                    line = line[6:]
                    print(f"Received line: {line}")
                    try:
                        event = json.loads(line)
                        print("Received event:", event)

                        # 4. Check for the 'answer' key
                        if "answer" in event:
                            payload = event["answer"]

                            if payload.get("type") == "answer":
                                answer_sdp = payload
                                print("WebRTC answer found. Stopping stream processing.")
                                # Break the line loop immediately
                                break

                    except json.JSONDecodeError:
                        print(f"Failed to parse extracted SSE payload as JSON: {line}")
                        pass

    if answer_sdp is None:
        raise HTTPException(500, "Did not find WebRTC answer in agent output")

    return answer_sdp


@app.post("/start")
async def rtvi_start(request: Request):
    """Mimic Pipecat Cloud's /start endpoint."""

    class IceServer(TypedDict, total=False):
        urls: Union[str, List[str]]

    class IceConfig(TypedDict):
        iceServers: List[IceServer]

    class StartBotResult(TypedDict, total=False):
        sessionId: str
        iceConfig: Optional[IceConfig]

    # Parse the request body
    try:
        request_data = await request.json()
        logger.debug(f"Received request: {request_data}")
    except Exception as e:
        logger.error(f"Failed to parse request body: {e}")
        request_data = {}

    # Store session info immediately in memory, replicate the behavior expected on Pipecat Cloud
    session_id = str(uuid.uuid4())
    active_sessions[session_id] = request_data

    result: StartBotResult = {"sessionId": session_id}
    if request_data.get("enableDefaultIceServers"):
        result["iceConfig"] = IceConfig(
            iceServers=[IceServer(urls=["stun:stun.l.google.com:19302"])]
        )

    return result


@app.api_route(
    "/sessions/{session_id}/{path:path}",
    methods=["GET", "POST", "PUT", "PATCH", "DELETE"],
)
async def proxy_request(
    session_id: str, path: str, request: Request, background_tasks: BackgroundTasks
):
    """Mimic Pipecat Cloud's proxy."""
    active_session = active_sessions.get(session_id)
    if active_session is None:
        return Response(content="Invalid or not-yet-ready session_id", status_code=404)

    if path.endswith("api/offer"):
        try:
            if request.method == HTTPMethod.POST.value:
                return await post_offer(request, session_id)
        except Exception as e:
            logger.error(f"Failed to parse WebRTC request: {e}")
            return Response(content="Invalid WebRTC request", status_code=400)

    logger.info(f"Received request for path: {path}")
    return Response(status_code=200)


@asynccontextmanager
async def lifespan(app: FastAPI):
    yield  # Run app


if __name__ == "__main__":
    parser = argparse.ArgumentParser(description="WebRTC demo")
    parser.add_argument(
        "--host", default="localhost", help="Host for HTTP server (default: localhost)"
    )
    parser.add_argument(
        "--port", type=int, default=7860, help="Port for HTTP server (default: 7860)"
    )
    parser.add_argument("--verbose", "-v", action="count")
    args = parser.parse_args()

    logger.remove(0)
    if args.verbose:
        logger.add(sys.stderr, level="TRACE")
    else:
        logger.add(sys.stderr, level="DEBUG")

    uvicorn.run(app, host=args.host, port=args.port)