Skip to main content
Applies to:
  • Plan -
  • Deployment -

​
Summary

Issue: Topics facets appear empty and traces show a Skipped status instead of generating summaries. Cause: Skipped means the default Thread preprocessor found no usable conversation text — this happens when traces do not store conversation content on LLM-type spans, which is what the default preprocessor reads. Resolution: Create a custom preprocessor that extracts conversation from your actual trace shape, set it as the project default, and then re-generate topics.

​
Resolution steps

​
Step 1: Confirm the cause

Open a trace in Logs and select the Thread tab in the Trace Viewer if the Thread view is empty, the preprocessor is not finding conversation content.

​
Step 2: Create a custom preprocessor

  1. In Logs, open any trace.
  2. Select the Thread tab.
  3. Click the config button.
  4. In the Preprocessor dropdown, select + Custom preprocessor (advanced).
  5. Enter your preprocessor code, see the Enable Topics - Write a custom preprocessor docs for examples.
  6. Enter a name, click Test to verify output, then click Save.

​
Step 3: Set the preprocessor as the project default

  1. Navigate to Settings → Advanced (under the Project section).
  2. Under Default preprocessor, select the preprocessor you just created.
  3. Click Save.

​
Step 4: Verify and re-generate topics

  1. Open a trace, go to the Thread tab, and confirm the conversation now appears.
  2. In Logs, click the Topics button (top right), select a facet, open a trace, and click Test in the Topics pane to confirm facet output.
  3. In Topics, click the three dots menu in the top right and select Process existing Traces.
  4. Select a Time range from the dropdown and click Process traces.