Examples and tests for previous_response_id (#512)

Examples + tests

examples/basic/previous_response_id.py

@@ -0,0 +1,66 @@
+import asyncio
+
+from agents import Agent, Runner
+
+"""This demonstrates usage of the `previous_response_id` parameter to continue a conversation.
+The second run passes the previous response ID to the model, which allows it to continue the
+conversation without re-sending the previous messages.
+
+Notes:
+1. This only applies to the OpenAI Responses API. Other models will ignore this parameter.
+2. Responses are only stored for 30 days as of this writing, so in production you should
+store the response ID along with an expiration date; if the response is no longer valid,
+you'll need to re-send the previous conversation history.
+"""
+
+
+async def main():
+    agent = Agent(
+        name="Assistant",
+        instructions="You are a helpful assistant. be VERY concise.",
+    )
+
+    result = await Runner.run(agent, "What is the largest country in South America?")
+    print(result.final_output)
+    # Brazil
+
+    result = await Runner.run(
+        agent,
+        "What is the capital of that country?",
+        previous_response_id=result.last_response_id,
+    )
+    print(result.final_output)
+    # Brasilia
+
+
+async def main_stream():
+    agent = Agent(
+        name="Assistant",
+        instructions="You are a helpful assistant. be VERY concise.",
+    )
+
+    result = Runner.run_streamed(agent, "What is the largest country in South America?")
+
+    async for event in result.stream_events():
+        if event.type == "raw_response_event" and event.data.type == "response.output_text.delta":
+            print(event.data.delta, end="", flush=True)
+
+    print()
+
+    result = Runner.run_streamed(
+        agent,
+        "What is the capital of that country?",
+        previous_response_id=result.last_response_id,
+    )
+
+    async for event in result.stream_events():
+        if event.type == "raw_response_event" and event.data.type == "response.output_text.delta":
+            print(event.data.delta, end="", flush=True)
+
+
+if __name__ == "__main__":
+    is_stream = input("Run in stream mode? (y/n): ")
+    if is_stream == "y":
+        asyncio.run(main_stream())
+    else:
+        asyncio.run(main())

tests/fake_model.py

@@ -63,6 +63,7 @@ class FakeModel(Model):
             "model_settings": model_settings,
             "tools": tools,
             "output_schema": output_schema,
+            "previous_response_id": previous_response_id,
         }
 
         with generation_span(disabled=not self.tracing_enabled) as span:
@@ -98,6 +99,14 @@ class FakeModel(Model):
         *,
         previous_response_id: str | None,
     ) -> AsyncIterator[TResponseStreamEvent]:
+        self.last_turn_args = {
+            "system_instructions": system_instructions,
+            "input": input,
+            "model_settings": model_settings,
+            "tools": tools,
+            "output_schema": output_schema,
+            "previous_response_id": previous_response_id,
+        }
         with generation_span(disabled=not self.tracing_enabled) as span:
             output = self.get_next_output()
             if isinstance(output, Exception):

tests/test_agent_runner.py

@@ -662,3 +662,86 @@ async def test_model_settings_override():
     # temperature is overridden by Runner.run, but max_tokens is not
     assert model.last_turn_args["model_settings"].temperature == 0.5
     assert model.last_turn_args["model_settings"].max_tokens == 1000
+
+
+@pytest.mark.asyncio
+async def test_previous_response_id_passed_between_runs():
+    """Test that previous_response_id is passed to the model on subsequent runs."""
+    model = FakeModel()
+    model.set_next_output([get_text_message("done")])
+    agent = Agent(name="test", model=model)
+
+    assert model.last_turn_args.get("previous_response_id") is None
+    await Runner.run(agent, input="test", previous_response_id="resp-non-streamed-test")
+    assert model.last_turn_args.get("previous_response_id") == "resp-non-streamed-test"
+
+
+@pytest.mark.asyncio
+async def test_multi_turn_previous_response_id_passed_between_runs():
+    """Test that previous_response_id is passed to the model on subsequent runs."""
+
+    model = FakeModel()
+    agent = Agent(
+        name="test",
+        model=model,
+        tools=[get_function_tool("foo", "tool_result")],
+    )
+
+    model.add_multiple_turn_outputs(
+        [
+            # First turn: a message and tool call
+            [get_text_message("a_message"), get_function_tool_call("foo", json.dumps({"a": "b"}))],
+            # Second turn: text message
+            [get_text_message("done")],
+        ]
+    )
+
+    assert model.last_turn_args.get("previous_response_id") is None
+    await Runner.run(agent, input="test", previous_response_id="resp-test-123")
+    assert model.last_turn_args.get("previous_response_id") == "resp-test-123"
+
+
+@pytest.mark.asyncio
+async def test_previous_response_id_passed_between_runs_streamed():
+    """Test that previous_response_id is passed to the model on subsequent streamed runs."""
+    model = FakeModel()
+    model.set_next_output([get_text_message("done")])
+    agent = Agent(
+        name="test",
+        model=model,
+    )
+
+    assert model.last_turn_args.get("previous_response_id") is None
+    result = Runner.run_streamed(agent, input="test", previous_response_id="resp-stream-test")
+    async for _ in result.stream_events():
+        pass
+
+    assert model.last_turn_args.get("previous_response_id") == "resp-stream-test"
+
+
+@pytest.mark.asyncio
+async def test_previous_response_id_passed_between_runs_streamed_multi_turn():
+    """Test that previous_response_id is passed to the model on subsequent streamed runs."""
+
+    model = FakeModel()
+    agent = Agent(
+        name="test",
+        model=model,
+        tools=[get_function_tool("foo", "tool_result")],
+    )
+
+    model.add_multiple_turn_outputs(
+        [
+            # First turn: a message and tool call
+            [get_text_message("a_message"), get_function_tool_call("foo", json.dumps({"a": "b"}))],
+            # Second turn: text message
+            [get_text_message("done")],
+        ]
+    )
+
+    assert model.last_turn_args.get("previous_response_id") is None
+    result = Runner.run_streamed(agent, input="test", previous_response_id="resp-stream-test")
+    async for _ in result.stream_events():
+        pass
+
+    assert model.last_turn_args.get("previous_response_id") == "resp-stream-test"