Python: [Bug]: devui no longer honors session (regression since 1.0.0b260219, present in 1.0.0rc1)

[jspv]

Description

DevUI multi-turn conversation, session isn't being honored. E.g.

user: "my name is Joe"
agent: "Hi Joe, nice to meet you!"
user: "what is my name"
agent: "I don’t know your name yet—you haven’t told me. What would you like me to call you?"

This is occurring in 1.0.0b260219 and 1.0.0rc1; 1.0.0b260130 works fine (although uses ChatAgent instead of Agent). Examples and potential fix below:

Fails in 1.0.0b260219 and 1.0.0rc1:

from agent_framework import Agent, tool
from agent_framework.openai import OpenAIChatClient
from agent_framework.devui import serve

@tool
def get_weather(location: str) -> str:
    """Get weather for a location."""
    return f"Weather in {location}: 72F and sunny"


# Create your agent
agent = Agent(
    name="WeatherAgent",
    client=OpenAIChatClient(),
    tools=[get_weather],
)

# Launch DevUI
serve(entities=[agent], auto_open=True)
# Opens browser to http://localhost:8080

Works in 1.0.0b260130 (note older syntax)

from agent_framework import ChatAgent, tool
from agent_framework.openai import OpenAIChatClient
from agent_framework.devui import serve

@tool
def get_weather(location: str) -> str:
    """Get weather for a location."""
    return f"Weather in {location}: 72F and sunny"


# Create your agent
agent = ChatAgent(
    name="WeatherAgent",
    chat_client=OpenAIChatClient(),
    tools=[get_weather],
)

# Launch DevUI
serve(entities=[agent], auto_open=True)
# Opens browser to http://localhost:8080

the following monkey patch demonstrates a potential fix the issue (sorry heading to work - no time to test and put in a PR, no idea what else this might break); key add was to finalize the stream before yielding the event.

# ---------------------------------------------------------------------------
# Workaround: DevUI streams agent.run() but never calls get_final_response(),
# so the result-hook that runs after_run providers (InMemoryHistoryProvider
# save_messages) never fires.  Monkey-patch _execute_agent to finalize the
# stream after iteration so session history is persisted across turns.
# ---------------------------------------------------------------------------
import agent_framework_devui._executor as _executor_mod
from agent_framework._clients import ResponseStream
from agent_framework_devui.models._openai_custom import (
    AgentStartedEvent,
    AgentCompletedEvent,
    AgentFailedEvent,
)

_orig_execute_agent = _executor_mod.AgentFrameworkExecutor._execute_agent


async def _patched_execute_agent(self, agent, request, trace_collector):
    """Wrap _execute_agent to call get_final_response() after streaming."""
    conversation_id = request._get_conversation_id()
    session = self.conversation_store.get_session(conversation_id) if conversation_id else None

    if not session:
        # No session — fall back to original (no history to persist)
        async for event in _orig_execute_agent(self, agent, request, trace_collector):
            yield event
        return

    # Session-aware path: capture stream ref so we can finalize it
    try:
        yield AgentStartedEvent()

        user_message = self._convert_input_to_chat_message(request.input)
        await self._ensure_mcp_connections(agent)

        stream = agent.run(user_message, stream=True, session=session)
        async for update in stream:
            for trace_event in trace_collector.get_pending_events():
                yield trace_event
            yield update

        # KEY FIX: finalize the stream so result-hooks (after_run) execute,
        # which persists conversation history to session.state.
        if isinstance(stream, ResponseStream):
            await stream.get_final_response()

        yield AgentCompletedEvent()

    except Exception as e:
        try:
            yield AgentFailedEvent(error=e)
        except Exception:
            pass
        yield {"type": "error", "message": f"Agent execution error: {e!s}"}


_executor_mod.AgentFrameworkExecutor._execute_agent = _patched_execute_agent

Code Sample

Error Messages / Stack Traces

Package Versions

agent-framework: 1.0.0rc1, agent-framework-devui: 1.0.0b260219

Python Version

Python 3.13

Additional Context

No response

[michelschep]

Same in DevUI with .NET.
Looks like a new session state is created after each question in the UI.
Therefor the context (older messages) is ignored.
When I send the second message in the conversation I see that RunStreamingAsync is called (in AIAgent) with AgentSession == null