Caution
Langfuse was acquired by ClickHouse, Inc. (announced 2026-01-16, alongside ClickHouse’s USD 400M Series D). Verified 2026-10-05.
About
Langfuse is an open-source LLM engineering platform (tracing, evals, prompt management). Per the ClickHouse announcement, Marc Klingen is CEO and the co-founders are Clemens Rawert and Max Deichmann; the founding year and Y Combinator batch are not verified. Klingen is quoted in that post saying Langfuse was built on ClickHouse because LLM observability and evaluation is a data problem.
Products
- Langfuse (cloud and self-hosted): see agent-evals-and-observability. Compare LangSmith.
- Traction as stated by ClickHouse at the announcement (vendor self-claims): 20,000+ GitHub stars, 26M+ monthly SDK installs, and use at 19 of the Fortune 50 and 63 of the Fortune 500.
Ownership
- Acquired by ClickHouse, Inc.; terms undisclosed. The team stated Langfuse stays open source (MIT) with cloud and self-hosting continuing.
Open items
- Headquarters not verified.
Sources
- https://clickhouse.com/blog/clickhouse-raises-400-million-series-d-acquires-langfuse-launches-postgres (fetched 2026-10-05)
- https://www.orrick.com/en/News/2026/01/Open-source-LLM-Observability-Langfuse-Acquired-by-ClickHouse-Inc (accessed 2026-10-01)
- https://github.com/orgs/langfuse/discussions/11593 (accessed 2026-10-01)