Skip to content

feat: integrate Langfuse for LLM observability #66

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom
Merged
DayuanJiang merged 3 commits into from
Dec 3, 2025
Merged

feat: integrate Langfuse for LLM observability #66

DayuanJiang merged 3 commits into from
Dec 3, 2025
+383 −3

Conversation

@DayuanJiang
Copy link
Owner

@DayuanJiang DayuanJiang commented Dec 3, 2025 •
edited
Loading

Summary

Add optional Langfuse observability integration for LLM tracing and analytics.

Features

  • Session tracking with unique sessionId per conversation (resets on clear)
  • User tracking via IP address (x-forwarded-for header)
  • Fully optional - only enabled if LANGFUSE_PUBLIC_KEY env var is set
  • Zero overhead for users who don't use Langfuse

Changes

  • Add instrumentation.ts with LangfuseSpanProcessor setup
  • Add experimental_telemetry to streamText calls (conditional)
  • Add sessionId state management in chat-panel.tsx
  • Add environment variable validation
  • Update env.example with Langfuse configuration docs

Setup (Optional)

# Add to .env.local
LANGFUSE_PUBLIC_KEY=pk-lf-...
LANGFUSE_SECRET_KEY=sk-lf-...
LANGFUSE_BASEURL=https://cloud.langfuse.com  # EU region
# or https://us.cloud.langfuse.com for US

Test Plan

  • Verify telemetry works with Langfuse configured
  • Verify no errors when Langfuse is not configured
  • Verify session resets on clear conversation
  • Code reviewed by 3 agents

@DayuanJiang
feat: integrate Langfuse for LLM observability
d84edb5 
- Add instrumentation.ts with Langfuse OpenTelemetry exporter
- Enable experimental telemetry on streamText calls
- Add instrumentationHook to Next.js config
- Install required dependencies (@vercel/otel, langfuse-vercel, etc.)
@vercel
Copy link

vercel bot commented Dec 3, 2025 •
edited
Loading

The latest updates on your projects. Learn more about Vercel for GitHub.

Project Deployment Preview Comments Updated (UTC)
next-ai-draw-io Ready Ready Preview Comment Dec 3, 2025 3:17pm

@DayuanJiang
feat: add optional Langfuse observability integration
30b598d 
- Add session tracking with unique sessionId per conversation
- Add user tracking via IP address (x-forwarded-for header)
- Make telemetry conditional - only enabled if LANGFUSE_PUBLIC_KEY is set
- Add environment variable validation in instrumentation.ts
- Add sessionId validation (type check + 200 char limit)
- Update env.example with Langfuse configuration docs
- Remove unused langfuse-vercel and @vercel/otel packages
@DayuanJiang DayuanJiang merged commit fa1b02a into main Dec 3, 2025
4 checks passed
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Reviewers

No reviews

Assignees

No one assigned

Labels

None yet

Projects

None yet

Milestone

No milestone

Development

Successfully merging this pull request may close these issues.

2 participants

@DayuanJiang