#langfuse

The LLM observability category has 4 distinct tool types in 2026. Confusing a reverse proxy with an SDK tracer costs trace coverage — not just $59/mo.

Langfuse vs Helicone for LLM observability in 2026: SDK span trees vs one-line proxy plus AI Gateway, pricing, real Claude agent test, and decision tree.

Langfuse rebuilt experiments as a first-class concept on April 13, 2026. Here is what changes for LLM evaluation workflows and how to migrate this week.

I instrumented a Claude Sonnet 4.6 + pgvector RAG app across 7 LLM observability platforms — Langfuse, Helicone, Phoenix, Braintrust, Opik, Traceloop, Lunary.