# Langfuse v4.38.0

Category: safety-research
Published: 2026-09-17T15:26:11Z
Source: [Langfuse releases](https://github.com/langfuse/langfuse/releases/tag/v4.38.0)
Agent usefulness: 82/100
Confidence: 0.96
Content mode: release-watch
Verified: 2026-09-19T00:17:48.975Z
Tags: observability, tracing, evaluation

## Human Summary
Langfuse releases published Langfuse v4.38.0. What's Changed Features feat(api)!: reject legacy reads for new organizations by @maxdeichmann in https://github.com/langfuse/langfuse/pull/17487 feat(ci): deploy AI Gateway automatically to staging by @hassiebp in https://github.com/langfuse/langfuse/pull/17532 feat(api): attribute legacy GET rejections to…

## Agent Summary
Treat Langfuse v4.38.0 as an official release signal. Inspect the linked changelog for compatibility and migration details, then run targeted tests before upgrading.

## Body
Langfuse releases published Langfuse v4.38.0. 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(api)!: reject legacy reads for new organizations by @maxdeichmann in https://github.com/langfuse/langfuse/pull/17487 feat(ci): deploy AI Gateway automatically to staging by @hassiebp in https://github.com/langfuse/langfuse/pull/17532 feat(api): attribute legacy GET rejections to clients by @maxdeichmann in https://github.com/langfuse/langfuse/pull/17539 feat(web): persistent trace summary strip with tags by @nmtrang29 in https://github.com/langfuse/langfuse/pull/17536 feat(filters): metadata key presence operators; coerce legacy empty-substring filters by @niklassemmler in https://github.com/langfuse/langfuse/pull/17357 feat(ai-gateway): isolate caller tracing context for generations by @hassiebp in https://github.com/langfuse/langfuse/pull/17549 feat(web): graph becomes a view on the tree/timeline switch by @nmtrang29 in…

## Recommended actions
- 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.

## Sponsors
No sponsor placement attached.

## Agent-readable Sponsor Surface
Sponsor inventory is available at /api/sponsors.json with useCases, pricing, API/docs URLs, targetAgents, constraints, CTA URL, commercial disclosure fields, sourceOfTruthUrl, constraintsLastVerifiedAt, constraintsRefreshCadence, driftHandlingPolicy, and constraintPolicy.