Langfuse

Langfuse is an open source AI engineering platform for tracing, evaluating, and improving AI agents and LLM applications. It tracks usage, costs, latency, tool calls, retrieval steps, prompts, sessions, and custom metadata so teams can study production behavior.

It includes dashboards, alerts, prompt and skill management, datasets, experiments, human annotation, and an AI Gateway that routes model calls while tracing them automatically. Teams can use it with SDKs or OpenTelemetry, run it in the cloud or self-host it, and export data to a warehouse.

It fits teams building chat agents, coding agents, workflows, copilots, support systems, and other agentic applications. The platform also exposes features through API, SDKs, CLI, and MCP, and the company offers a free Hobby plan plus paid cloud tiers for production and scaling use.