# Langfuse v3.225.9

Category: safety-research
Published: 2026-09-22T06:36:00Z
Source: [Langfuse releases](https://github.com/langfuse/langfuse/releases/tag/v3.225.9)
Agent usefulness: 82/100
Confidence: 0.96
Content mode: release-watch
Verified: 2026-09-22T12:17:22.746Z
Tags: observability, tracing, evaluation

## Human Summary
Langfuse v3.225.9 fixes an authentication issue by evicting the API key cache immediately when a key is deleted.

## Agent Summary
Langfuse v3.225.9 introduces a patch backport (PR 17767) that evicts the API key cache entry following row deletion in the database, ensuring revoked or deleted keys are immediately invalidated in memory.

## Body
Langfuse v3.225.9 is a maintenance release addressing API key lifecycle management. It includes a backport fix ( 17767, backporting 17651) ensuring the API key cache is explicitly cleared after an API key row is deleted from the database. This guarantees that revoked or deleted keys cannot be authenticated against a stale cache.

## Recommended actions
- Upgrade Langfuse instances running v3 to v3.225.9 to ensure deleted API keys are immediately invalidated in cache.

## 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.