Open Source Agent Evals &Observability

Launch, observe, improve — repeat.

Langfuse connects tracing, monitoring, datasets, experiments, and evaluation in one continuous loop. Use production signals to understand behavior, test improvements, and ship better agents with confidence.

The full AI engineering loop

See how observability, prompts, evals, experiments, and human feedback work together.

All the tools, oneintegrated platform.

One integrated platform to trace, manage prompts, evaluate, and experiment from prototype to production scale.

Works with any stack.

Langfuse works with any language and framework supporting OTel instrumentation. Additionally, 100+ integrations make getting started even easier. No framework lock-in.

Open platform. Open source.

We are huge fans of open standards and data portability. Langfuse won't lock in your data, ever.

Self-host at scale

Enterprise scale and security.

Traditional observability handles many small spans. LLM systems run differently. Every step carries rich, verbose I/O that legacy platforms can't handle at scale. Langfuse ingests and queries LLM traces reliably at enterprise scale while following strict compliance frameworks.

Why use Langfuse?

Langfuse is the most widely adopted open-source LLM engineering platform. Developers who value open-source and control over their data build production grade agents and LLM applications with Langfuse.

Langfuse powers the entire development cycle from prototype to full scale production loads.