The error you provided does not contain a stack trace.

[shangdev]

This is my code, For openai API.

const abortController = new AbortController();
      await fetchEventSource(process.env.OPENAI_ENDPOINT + '/v1/chat/completions', {
        signal: abortController.signal,
        method: 'POST',
        headers: {
          Authorization: 'Bearer ' + process.env.OPENAI_KEY,
          'Content-Type': 'application/json',
        },
        body: JSON.stringify({
          model: model,
          messages: messagesAI,
          stream: true,
          temperature: 0,
        }),
        async onopen(response) {
          if (response.ok && response.headers.get('content-type') === EventStreamContentType) {
            return; // everything's good
          } else if (response.status >= 400 && response.status < 500 && response.status !== 429) {
            // client-side errors are usually non-retriable:
            throw new FatalError();
          } else {
            throw new RetriableError();
          }
        },
        onmessage(msg) {
          if (msg.data === '[DONE]') {
            abortController.abort();
            return;
          }
        },
        onerror(err) {
          if (err instanceof FatalError) {
            console.error('[Request] FatalError', err);
          } else if (err instanceof RetriableError) {
            console.error('[Request] RetriableError', err);
          } else {
            console.error('[Request] error', err);
            throw err;
          }

          return;
        },
        openWhenHidden: true,
});

Each request will print an error message on the console:

[piotr-cz]

Instead try to not await, but add .catch(error => console.log(error)) at the end.

Another thing I noticed is that in the onerror handler, you should throw on FatalError, not on other errors