RemoteA2aAgent fetches the agent card and creates a new httpx client on every turn #7629

import asyncio
from collections import Counter

import httpx
import uvicorn
from google.adk.a2a.utils.agent_to_a2a import to_a2a
from google.adk.agents import Agent
from google.adk.agents.remote_a2a_agent import AGENT_CARD_WELL_KNOWN_PATH, RemoteA2aAgent
from google.adk.models.base_llm import BaseLlm
from google.adk.models.llm_response import LlmResponse
from google.adk.runners import InMemoryRunner
from google.genai import types


class FakeLlm(BaseLlm):
  model: str = "fake"

  async def generate_content_async(self, llm_request, stream=False):
    yield LlmResponse(content=types.Content(role="model", parts=[types.Part(text="ok")]))


hits = Counter()
created = [0]
_init = httpx.AsyncClient.__init__


def _count_init(self, *a, **k):
  created[0] += 1
  _init(self, *a, **k)


def count_requests(app):
  async def wrapped(scope, receive, send):
    if scope["type"] == "http":
      hits[(scope["method"], scope["path"])] += 1
    await app(scope, receive, send)
  return wrapped


async def main():
  remote_app = to_a2a(Agent(name="weather", model=FakeLlm(), instruction="answer"), port=8771)
  server = uvicorn.Server(uvicorn.Config(count_requests(remote_app), port=8771, log_level="warning"))
  task = asyncio.create_task(server.serve())
  while not server.started:
    await asyncio.sleep(0.05)

  httpx.AsyncClient.__init__ = _count_init
  remote = RemoteA2aAgent(name="weather", agent_card=f"http://localhost:8771{AGENT_CARD_WELL_KNOWN_PATH}")
  root = Agent(name="coordinator", model=FakeLlm(), instruction="answer", sub_agents=[remote])
  runner = InMemoryRunner(agent=root, app_name="repro")
  session = await runner.session_service.create_session(app_name="repro", user_id="u")

  for _ in range(5):
    msg = types.Content(role="user", parts=[types.Part(text="hi")])
    async for _ in runner.run_async(user_id="u", session_id=session.id, new_message=msg):
      pass

  print("turns: 5 (the coordinator answers itself, it never transfers)")
  print("agent card GETs:", hits[("GET", AGENT_CARD_WELL_KNOWN_PATH)])
  print("httpx.AsyncClient created:", created[0])
  print("card cached on the instance I passed in:", remote._agent_card is not None)

  await runner.close()
  server.should_exit = True
  await task


asyncio.run(main())