Trail proxy setup

[xiaoyifan]

Note

Add trail_id-based chat and traces endpoints with Langfuse tagging and Redis tracking, while keeping legacy rollout routes intact.

• Routes (FastAPI):
  • Add trail chat completion endpoints: /trails/{trail_id}/chat/completions (+ v1 and project_id variants).
  • Add trail traces endpoints: /trails/{trail_id}/traces and /trails/{trail_id}/traces/pointwise (+ variants).
  • Preserve legacy rollout-based routes.
• Tagging & Tracking:
  • Inject trail_id and insertion_id tags for trail requests; retain rollout tag set for legacy paths.
  • Generalize Redis tracking to a unified tracking_key (trail_id or rollout_id) for insertion IDs.
• Langfuse integration:
  • Support trail-based filtering in trace list/detail with retry/backoff.
  • Use tracking_key in logs, completeness checks, and pointwise latest-trace fetch.
• Models:
  • Extend ChatParams with optional trail_id.
• Tests:
  • Add tests for trail routes registration, tag injection (trail vs rollout), and Redis key usage; verify health and legacy route presence.

^{Written by Cursor Bugbot for commit 911daca. This will update automatically on new commits. Configure here.}

[cursor]

Bug: Missing variable definitions in fetch_langfuse_traces function

The fetch_langfuse_traces function uses tracking_key and tracking_label variables (at lines 254, 256, 259, 263, 280, 336, 356, 373, 378, 382) but these are never defined in this function. The function only extracts rollout_id at line 226. The corresponding pointwise_fetch_langfuse_trace function was correctly updated to define both tracking_key and tracking_label from trail_id and rollout_id, but this definition block was not added to fetch_langfuse_traces. This will cause a NameError at runtime when accessing the trail traces endpoints.