useStream React Hook Doesn't Capture onError

[jmccraw]

Hi. I'm using the useStream React hook and trying to test for if a given threadId doesn't exist in LangChain.

I can see the fetcher receiving the 404 response, but the onError callback never fires. Is this just a bug? Wasn't sure if I wasn't using this correctly:

  const thread = useStream<{ messages: Message[] }>({
    apiUrl: MY_URL,
    apiKey: MY_KEY,
    assistantId: 'agent',
    messagesKey: 'messages',
    threadId: threadID,
    onThreadId: setThreadID,
    onCreated: (run) => {
      console.log('Stream created', run);
    },
    onCustomEvent: (data, opts) => {
      console.log('Stream Custom event:', data, opts);
    },
    onDebugEvent: (event) => {
      console.log('Stream Debug event:', event);
    },
    onError: (error, run) => {
      console.error('Stream error:', error, run);
    },
    onFinish: (state, run) => {
      console.log('Stream Finished:', state, run);
    },
    onLangChainEvent: (data) => {
      console.log('Stream LangChain Event:', data);
    },
    onMetadataEvent: (metadata) => {
      console.log('Stream Metadata Event:', metadata);
    },
    onUpdateEvent: (chunk) => {
      console.log('Stream Update Event, ', chunk);
    },
  });

Some of these other ones don't seem to fire, either. Like onCreated.

EDIT: I get a POST 404 Not Found error. There's an uncaught promise error for: HTTP 404: {"detail":"Not Found"}

[jmccraw]

When using authentication and you get a 401 or something, it does seem to trigger the onError handler

[jmccraw]

For anyone else looking, it seems the best way to do this in the current version is to create a custom callback on the callerOptions.fetch property that then handles receipt of the fetch response and processes it that way.

[chatrtham]

😭😭 Thank you so much! I've been having problems on onCreated and onCustomEvent for almost a week now

[chatrtham]

U just saved my company from a super tough week!! Love u from Thailand, Justin 😭 😭 @jmccraw