Langfuse

Langfuse is an open-source LLM engineering platform that provides tracing, evaluation, prompt management, and observability for LLM applications and agents in production. It captures detailed traces of every LLM call, tool invocation, and retrieval step, enabling teams to debug failures, evaluate output quality, and monitor costs and latency across their AI systems. AI engineering teams building production LLM applications use Langfuse to gain the observability and evaluation infrastructure needed to systematically improve application quality and reliability beyond what ad-hoc testing provides.