Dayuan Jiang fa1b02ad78 feat: integrate Langfuse for LLM observability (#66) ...

* feat: integrate Langfuse for LLM observability

- 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.)

* feat: add optional Langfuse observability integration

- 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

* fix: remove deprecated instrumentationHook (enabled by default in Next.js 15)

2025-12-04 00:23:09 +09:00

..

route.ts

feat: integrate Langfuse for LLM observability (#66)

2025-12-04 00:23:09 +09:00

xml_guide.md

feat: add XML structure guide to system prompt for smaller models (#51)

2025-12-03 16:14:53 +09:00