Calling .astream inside of another graph's .astream_events will set stream_mode="value" regardless of config

[lucaslulucaslu]

Checked other resources

• [X] I added a very descriptive title to this issue.
• [X] I searched the LangGraph/LangChain documentation with the integrated search.
• [X] I used the GitHub search to find a similar question and didn't find it.
• [X] I am sure that this is a bug in LangGraph/LangChain rather than my code.
• [X] I am sure this is better as an issue rather than a GitHub discussion, since this is a LangGraph bug and not a design question.

Example Code

cannot have code here due to security issue

Error Message and Stack Trace (if applicable)

No response

Description

I have a graph A streaming LLM tokens, I tested it and can confirm I get updates as streaming. Then I have another graph B which is invoked by B.astream_events, then invoke A.astream, I can only get values of every GraphState, no matter I set stream_mode to "value" or "update"

System Info

latest langgraph mac python 3.12

[vbarda]

@lucaslulucaslu could you write some pseudocode to illustrate this issue better?