Langfuse

Open-source LLM observability you can self-host

AI Agents / Memory & Evals · Open-Core · 36.1k

Reviewed 2026-08-19 · last push 2026-10-21 · repo checked 2026-10-21

What's Good

Langfuse is the open-source default for LLM observability. The entire stack—web app, worker, Postgres, ClickHouse, Redis—runs on your infrastructure under MIT license. OpenTelemetry-style tracing captures the full tree of spans and generations with token counts, latency, cost, and model metadata.

The Catch

License: the core is MIT, but anything under the ee/ directories is under a separate enterprise license — check which features you rely on before calling your deployment fully MIT. Self-hosting means self-operating—you are running Postgres, ClickHouse, Redis, and the app. Observability-first means evals are layered on, not central.

Verdict

The LLM observability platform for teams who want to own their data.

Embed

Maintainer? Add the badge to your README. It is free, links to this review, and there is no paid version.

Markdown

[![Reviewed on Stack Gems](https://stackgems.com/badge/langfuse.svg)](https://stackgems.com/gems/langfuse)

HTML

<a href="https://stackgems.com/gems/langfuse"><img src="https://stackgems.com/badge/langfuse.svg" alt="Langfuse reviewed on Stack Gems" height="20"></a>

AI Agents →

Related