parent/child spans for ai.generateText / ai.generateText.doGenerate

[rgarcia]

Description

I am using the experimental_tracing option and seeing that the spans generated are all independent traces. I was expecting there to be a way to:

1. Pass in a parent span context so that the initial ai.generateText span is a child of something else
2. Have the other spans created by the AI SDK, ai.generateText.doGenerate + ai.toolCalls be children of the top-level ai.generateText span.

Code example

This is what's happening (three independent traces):

This is what I'd like (one trace with three spans):

AI provider

@ai-sdk/openai@latest

Additional context

No response

[lgrammel]

Which observability provider are you using? spans are linked automatically

[rgarcia]

Using Braintrust. I figured out a fix: if I make a call to the otel SDK's startActiveSpan in my code surrounding the AI SDK generateText call, then the spans generated by the AI SDK get correctly nested. Doesn't seem ideal but it works for now. If you point me to any test cases related to span nesting and trace IDs (e.g. checking that they're all under the same trace ID) I could maybe try my hand at a repro

[lgrammel]

Since this works with other integrations, my hunch is that this is an issue in the braintrust integration. I've informed the braintrust team.

[aphinx]

Hello from Braintrust 👋 I played around with the integration a bit today, and for me the spans do appear to be nested correctly under a single trace without having to manually start a parent span. If you can provide some sample code or more details on your tracing setup, I'd be happy to dig further.

[lgrammel]

Which versions are you using (otel versions, ai sdk versions, braintrust versions if any)

[rgarcia]

Well now I'm not sure what's going on... broke it down to the bare minimum repro and can't reproduce it anymore. Was definitely seeing it at some point though (screenshot as proof ha). I'll close the issue for now.