Langfuse
ObservabilityOpen source · MIT (core; ee/ is commercial)★ 35,358（2026-10-04）Self-hosted
Open-source LLM observability and evaluation, acquired by ClickHouse in 2026.
Langfuse is an open-core LLM observability and evaluation platform whose repository is MIT-licensed except for the ee/ directory; ClickHouse acquired it in January 2026 and committed to keeping the MIT product open, with Cloud and self-hosted running the same codebase on ClickHouse.
Caveat: Enterprise features (RBAC, audit logs) live in the separately licensed ee/ directory.
Key facts
| Category | Observability |
|---|---|
| License | MIT (core; ee/ is commercial) |
| Language | TypeScript |
| Self-hosted | Yes |
| GitHub stars | 35,358 (2026-10-04) |
| Last push | 2026-10-03 |
| Last verified | 2026-10-04 |
| Repository | https://github.com/langfuse/langfuse |
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