{"schemaVersion":"2026-07-21.signal.v2","id":"live-b4f66609d8890fcc9f02","title":"Langfuse v4.39.0","slug":"langfuse-v4-39-0-langfuse-v4-39-0-cc9f02","url":"https://www.niubiagent.com/signals/langfuse-v4-39-0-langfuse-v4-39-0-cc9f02","jsonUrl":"https://www.niubiagent.com/api/posts/langfuse-v4-39-0-langfuse-v4-39-0-cc9f02.json","markdownUrl":"https://www.niubiagent.com/content/langfuse-v4-39-0-langfuse-v4-39-0-cc9f02","summaryHuman":"Langfuse releases published Langfuse v4.39.0. What's Changed Features feat(web): publish event-loop delay for autoscaling by @sumerman in 17632 feat(automations): filter prompt events by label by @tobi12345 in 17612 feat(ai-gateway): add phase spans so request traces have no gaps by @hassiebp in 17640 feat(ai-gateway): record Codex client metadata as agent…","summaryAgent":"Treat Langfuse v4.39.0 as an official release signal. Inspect the linked changelog for compatibility and migration details, then run targeted tests before upgrading.","category":"safety-research","tags":["observability","tracing","evaluation"],"sourceName":"Langfuse releases","sourceUrl":"https://github.com/langfuse/langfuse/releases/tag/v4.39.0","publishedAt":"2026-09-21T11:21:23Z","curatedAt":"2026-09-21T12:17:45.988Z","confidence":0.96,"agentUsefulness":82,"sponsorIds":[],"language":"en","contentMode":"release-watch","verifiedAt":"2026-09-21T12:17:45.988Z","changeType":"release","actionItems":["Review the official Langfuse releases release notes before upgrading.","Check compatibility, migration, and security notes against your current agent stack.","Run focused regression tests before production rollout."],"body":"Langfuse releases published Langfuse v4.39.0. This release-watch entry was generated from the project's official GitHub release feed and is kept separate from human-reviewed editorial analysis. Release notes: What's Changed Features feat(web): publish event-loop delay for autoscaling by @sumerman in 17632 feat(automations): filter prompt events by label by @tobi12345 in 17612 feat(ai-gateway): add phase spans so request traces have no gaps by @hassiebp in 17640 feat(ai-gateway): record Codex client metadata as agent metadata by @hassiebp in 17641 feat(auth): authorize every ingestion event through the policy core by @marksalpeter in 16715 feat(otel): simulate worker admission in shadow mode by @sumerman in 17437 feat: return conversation history and current turn per thread by @marliessophie in 17613 feat(langchain): add serialized generation result fixture for LangChain messages normalization by @marliessophie in 17589 feat(in-app-agent): support Vertex AI for instance AI features by @toyayuto in 17390 feat(api): route prompt public handlers through the auth seam by @marksalpeter in 17533…","sponsors":[]}