nightireN
Convex Community•7mo ago•
6 replies
nightire

Cannot use httpAction to send langgraph streaming events

I want to use 
httpAction
 to build an api for streaming events that produced by langgraph.js, below is what I do and errors I had encountered:

1. First, I made a very simple demo, only produce stream events by using langchain's openai model provider, is works fine
2. Next, I wrote a relative complex langgraph agent (I'm sure it works), this time convex throw an error to inform using "use node"
3. Since 
httpAction
 does not allow "use node", I extract all agent codes into a internal action
4. Then I invoke this internal action in 
httpAction
 to get the stream, and I saw this error:

8/19/2025, 5:16:00 AM [CONVEX A(survey/creator:testing)] Uncaught Error: IterableReadableStreamWithAbortSignal {"reader":"undefined","_abortController":{},"_reader":{}} is not a supported Convex type.

8/19/2025, 5:16:00 AM [CONVEX H(POST /testing)] Uncaught Error: Uncaught Error: IterableReadableStreamWithAbortSignal {"reader":"undefined","_abortController":{},"_reader":{}} is not a supported Convex type.


It seems like I can't return a 
IterableReadableStreamWithAbortSignal
 object (which generated by 
langgraphagent.streamEvents
 method) through 
internalAction
? What can I do to make it work?

UPDATE: After a step-by-step debug, I can confirm the problem is caused by this line:

const agent = graph.compile()


If I put this line in the 
httpAction
, it errors because it depends on 
"node:async_hooks"
 which requires using 
"use node"
 directive

If I move this line to an 
internalAction
 and return the result, Convex will complain 
CompiledStateGraph
 is not a supported Convex type

I was trapped at this step, anyone can help me out?
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