Issue: Nested Run is Empty Inside Evaluator Function

[tobernguyen]

Issue you'd like to raise.

For context, we’re using TypeScript Langchain + Langsmith as part of our stack, which allows us to automatically and neatly view all the traces for intermediate steps of our chatbot in the Langsmith portal.

I’m currently working on an evaluation script that inspects a run and retrieves all nested runs (e.g., from a RAG tool) to extract the retrieved documents for evaluation purposes. However, I’ve encountered an issue:

• The Run passed to the evaluator only contains one child run, which is the root run, and this root run doesn’t contain any other child runs.

• When I inspect the same experiment in Langsmith, all the expected traces/runs are visible and appear correctly (screenshot attached for reference).

Could you help troubleshoot why the nested traces are not accessible within the evaluator function? Are there additional configurations or steps I might have missed to ensure the evaluator has access to all child runs?

Langsmith version: 0.2.14

Suggestion:

No response