create_react_agent with structured output ignores last agent message

[adamlundqvist]

I like the create_react_agent because it is simple to get to a first draft when building agent. Now that it provides structured output, it is even more valuable.

But I can't understand why the generate_structured_response in the agent ignores the last message from the react agent. This seems counter productive as the agent typically should return the summary of its work in the last message. The current implementation ignores that summary and (at least for my view of agents) makes the structured output unusable.

Here the related code from create_react_agent:
def generate_structured_response(
state: StateSchema, config: RunnableConfig
) -> StateSchema:
# NOTE: we exclude the last message because there is enough information
# for the LLM to generate the structured response
messages = _get_state_value(state, "messages")[:-1]
structured_response_schema = response_format
if isinstance(response_format, tuple):
system_prompt, structured_response_schema = response_format
messages = [SystemMessage(content=system_prompt)] + list(messages)

    model_with_structured_output = _get_model(model).with_structured_output(
        cast(StructuredResponseSchema, structured_response_schema)
    )
    response = model_with_structured_output.invoke(messages, config)
    return {"structured_response": response}

It would imho be a significant improvement to not ignore the last message from the agent.

[vbarda]

@adamlundqvist that has already been resolved in the most recent versions - please update to the latest version of langgraph-prebuilt - pip install -U langgraph-prebuilt

we'll make sure to bundle the latest version in langgraph as well

[adamlundqvist]

Wonderful, then I will use it from there instead, thanks a lot!!

[vbarda]

you won't even need to change anything in imports etc, just update the langgraph-prebuilt version :)

[adamlundqvist]

yes, and it works flawless! Thanks!

[Hisir0909]

not ignore the last message from the agent

This may cause the problem: Prefix can not work with json mode.
This is because the last message's role is assistant.
Affected vendors include: siliconflow.cn, etc.

[hero821]

same

[dvdface]

not ignore the last message from the agent

This may cause the problem: Prefix can not work with json mode. This is because the last message's role is assistant. Affected vendors include: siliconflow.cn, etc.

Does this issue fixed?