Agent skill · data analytics · jeremylongshore
langfuse-common-errors
Diagnose and fix common Langfuse errors and exceptions.
Why this skill is useful
Provides specific troubleshooting commands and solutions for common Langfuse errors that the AI wouldn't reliably generate on its own.
What it needs
Requires langfuse-sdk installed locally. About 5k tokens when loaded. Last updated 2026-08-07. 2,604 stars on the source repository.
What this skill does
Langfuse Common Errors Overview Diagnostic reference for the 10 most common Langfuse integration errors, with real error messages, root causes, and tested solutions. Prerequisites Langfuse SDK installed API credentials configured Access to application logs or console output Error Reference 1. Authentication Failed (401) Error: Cause: API key missing, expired, revoked, or keys from wrong project. Fix: 2. Traces Not Appearing in Dashboard Symptom: Code runs without errors but no traces show in UI. Root causes (in order of likelihood): 1. Data not flushed before process exits 2. Wrong project keys (traces going to different project) 3. Dashboard filter hiding traces Fix: 3. Network / Connection Errors Error: Fix: 4. Missing Token Usage Symptom: Generations appear but token counts show zero. Fix: 5. Spans Stuck "In Progress" (v3) Symptom: Spans show as in-progress indefinitely in the dashboard. Fix: 6. Duplicate Traces Symptom: Same operation creates multiple traces. Fix: 7. SDK Import Errors Error: Fix: 8. Environment Variable Not Loaded Error: Fix: 9. Self-Hosted Connection Issues Error: Fix: 10. Rate Limiting (429) Error: Fix: Quick Diagnostic Script Escalation Path 1. Run diagnostic script above 2. Collect debug bundle with langfuse-debug-bundle skill 3. Check Langfuse Status 4. Search GitHub Issues 5. Ask in Discord Instructions 1. Copy the exact error, SDK version, and Langfuse base URL from the failing environment. 2. Match it to the error reference above and apply the smallest listed fix. 3. Run the diagnostic script without printing secret values. 4. Confirm one trace or score appears in the intended project before retrying production traffic. 5. If the issue persists, collect the debug bundle and follow the escalation path. Output Report the matched failure class, the configuration or code change made, the diagnostic result, and whether a new trace reaches the expected Langfuse project. …
How to use it
Reference it in AdaL, Claude Code, Cursor or any coding agent — nothing to install:
@skills jeremylongshore/langfuse-common-errors