Open-source LLM engineering platform for tracing, evals, and prompt management.
Langfuse is an open-source LLM observability and engineering platform offering tracing, evaluations, prompt management, and analytics for agent and RAG applications. It can be self-hosted for free or used via Langfuse Cloud with usage-based pricing. Langfuse was acquired by ClickHouse in early 2026.
Self-hosting is free (open-source). Cloud: free tier up to ~50K units/month, Core $29/month, Pro $199/month, with usage overage.
price from · as of 2026-11-03