Tool-calling runs get quadratically slower: completed tool calls are re-fingerprinted every turn #5382

import asyncio, sys, time, json
from agents import Agent, Runner, function_tool, ModelResponse, Usage, RunConfig
from agents.models.interface import Model
from openai.types.responses import ResponseFunctionToolCall, ResponseOutputMessage, ResponseOutputText

N = int(sys.argv[1]) if len(sys.argv) > 1 else 200
MODE = sys.argv[2] if len(sys.argv) > 2 else "run"

@function_tool
def lookup(q: str) -> str:
    return "result for " + q + " " + "x" * 200

class FakeModel(Model):
    def __init__(self, n):
        self.i = 0; self.n = n
    def _out(self):
        self.i += 1
        if self.i > self.n:
            return [ResponseOutputMessage(id=f"m{self.i}", type="message", role="assistant", status="completed",
                content=[ResponseOutputText(text="done", type="output_text", annotations=[], logprobs=[])])]
        return [ResponseOutputMessage(id=f"m{self.i}", type="message", role="assistant", status="completed",
                    content=[ResponseOutputText(text="thinking " * 20, type="output_text", annotations=[], logprobs=[])]),
                ResponseFunctionToolCall(id=f"f{self.i}", call_id=f"c{self.i}", type="function_call", name="lookup",
                    arguments=json.dumps({"q": f"query {self.i}"}))]
    async def get_response(self, *a, **k):
        return ModelResponse(output=self._out(), usage=Usage(), response_id=None)
    async def stream_response(self, *a, **k):
        from openai.types.responses import ResponseCompletedEvent, Response
        out = self._out()
        yield ResponseCompletedEvent(type="response.completed", sequence_number=0, response=Response(
            id="r", created_at=0, model="fake", object="response", output=out, tool_choice="auto", tools=[],
            parallel_tool_calls=True))

async def main():
    agent = Agent(name="a", instructions="x", model=FakeModel(N), tools=[lookup])
    t = time.perf_counter()
    if MODE == "stream":
        r = Runner.run_streamed(agent, "hi", max_turns=N + 5)
        async for _ in r.stream_events(): pass
    else:
        r = await Runner.run(agent, "hi", max_turns=N + 5)
    dt = time.perf_counter() - t
    print(f"{MODE} N={N} {dt*1000:.1f} ms items={len(r.new_items)} out={r.final_output!r}")
    return r

if __name__ == "__main__":
    asyncio.run(main())