Directory / Langfuse
Langfuse
Verified
Open-source LLM observability you can self-host.
Langfuse is an open-source platform for tracing, prompt management, and evals of LLM/agent applications. You can self-host or use Langfuse Cloud. It is the default open log for factories that are not already in Datadog.
- Model independence
- Multi-model
- Deployment
- Cloud, Self-hosted
- Open source
- Yes
- License
- MIT (see repo for any enterprise modules)
- Pricing model
- Mixed
- Added / updated
- 19 Aug 2026 / 19 Aug 2026
langfuse.com · Docs · Source
Editorial take
Langfuse is the observability listing we would install on a self-hosted factory. Traces are not output. Wire them to PRs or you have a graveyard of spans. MIT core; cloud is optional.
Strengths
- Self-hostable traces, prompts, and evals.
- Model-agnostic.
- Open-source default in this category.
Limitations
- Will not make you measure merge/revert unless you do that work.
- Cloud vs OSS features.
- Not an execution harness.
Compare
- vs langsmith — Open-source LLM observability versus the LangChain control plane.