🐛 Bug: How to emit state correctly in CoAgents?

[elupanov]

♻️ Reproduction Steps

I have a LangGraph node with the following code

async def exercise_request(
    state: State, config: RunnableConfig
):
    state['exercise_is_generating'] = True
    await copilotkit_emit_state(config, state)

    exercise_type = _get_exercise_type(state)
    topic = _get_topic(state)

    prompt = PROMPT.format(topic=topic)
    response = await _generate_task(prompt, config)

    ids = state.get("exercise_messages_ids", [])
    ids.append(response.id)

    state["exercise_messages_ids"] = ids
    state["requested_exercise"] = ""
    state["messages"].append(response)
    state['exercise_is_generating'] = False

    return state

async def _generate_task(prompt: str, config: RunnableConfig) -> str:
    gpt4o_mini = "gpt-4o-mini"
    temperature = 0.3
    model = ChatOpenAI(
        model=gpt4o_mini, temperature=temperature)
    response = await model.ainvoke(prompt, config=config)
    return response

When the node execution starts I set exercise_is_generating in state to True and set it to False at the end function.
On the UI I use hook to read the state.

 const { state } = useCoAgent<AgentState>({
    name: "language_agent",
    initialState: { 
      language: language,
      level: level,
      conversation_language: conversationLanguage,
      predefined_topics: topics,
      exercise_is_generating: false
    },
  });

exercise_is_generating has a true value once the state is emitted with copilotkit_emit_state. But it is immediately has false after. It has already a false value before a new message is streaming (see _generate_task function).

What is the right way to emit the state in such case? Thank you!
CoAgents is the best thing I found out recently. Awesome work!

✅ Expected Behavior

❌ Actual Behavior

𝌚 CopilotKit Version

1.3.15

📄 Logs (Optional)

No response

[elupanov]

It seems that there is an issue because the state is overridden and emitting to client when the message is streamed to the client in await model.ainvoke(prompt, config=config).

[NathanTarbert]

Thank you for flagging this @elupanov, we are looking into this.
When I hear back from engineering I'll let you know

[officialrobert]

Hi @elupanov

IMHO: Alternatively, I think you can set state['exercise_is_generating'] = True in a previous node (you may create a new one), emit an event, and then return the state. After that, set state['exercise_is_generating'] = False in this exercise_request node, emit another event before returning the state.

[elupanov]

Hi @elupanov

IMHO: Alternatively, I think you can set state['exercise_is_generating'] = True in a previous node (you may create a new one), emit an event, and then return the state. After that, set state['exercise_is_generating'] = False in this exercise_request node, emit another event before returning the state.

Thanks for the hint.
But it would be great to have a fix for steaming messages use case.

[officialrobert]

Should making a state/config obj copy from copilotkit_emit_state fix this? @elupanov