Alex S.

Ok yeah I'm not using a framework so I have to manually instrument all this.

"there's actually no real object called a trace - it's just a series of spans" ok that's super clarifying that that's the position you take. I think would be super helpful to say that in your docs somewhere too FWIW.

or @tracer.guardrails or @tracer.reranker etc

And what's the equivalent of @tracer.embedding since it seems like this isn't implemented?

Ok yes I see that now! I'll update my notes to reflect your suggested solution. It's unclear to me why I see the same thing in both the traces and the spans tab of the dashboard, though. Shouldn't I see spans in the span tab and traces in the traces tab? I guess it's unclear to me what the difference is for Phoenix in how these two things get handled. It seems that a chain is somehow some kind of a parent object? or is it just treated that way because of how the code is constructed? I guess I'll experiment a bit more to get to the bottom of this!

I tried and couldn't figure it out Xander S. https://mlops.systems/posts/2025-06-04-instrumenting-an-agentic-app-with-arize-phoenix-and-litellm.html (also cc: Mikyo via the LLM Evals course discord)

Xander S. I was referring to these: https://docs.litellm.ai/docs/observability/phoenix_integration.

ok RunLLM and if I have an agentic application and I want to group a bunch of llm calls, embeddings etc i.e. lots of spans under a single trace, how best to group those together given that the calls all happen in different files etc across the codebase?

ok RunLLM and if I have an agentic application and I want to group a bunch of llm calls, embeddings etc i.e. lots of spans under a single trace, how best to group those together given that the calls all happen in different files etc across the codebase?