# arize-phoenix: v20.19.0

Category: safety-research
Published: 2026-10-01T22:59:10Z
Source: [Arize Phoenix releases](https://github.com/Arize-ai/phoenix/releases/tag/arize-phoenix-v20.19.0)
Agent usefulness: 72/100
Confidence: 0.96
Content mode: release-watch
Verified: 2026-10-02T00:17:49.250Z
Tags: observability, evaluation, tracing

## Human Summary
Arize Phoenix v20.19.0 introduces a new DECISION span kind for platform tracing and routes recorded applications to separate projects in datagen.

## Agent Summary
Arize Phoenix v20.19.0 adds the DECISION span kind across the tracing platform, routes recorded applications to individual projects in datagen , fixes external resource flag handling for WASM and UI, and removes legacy evaluation cookbooks.

## Body
Arize Phoenix version 20.19.0 has been released with the following updates: - Tracing: Introduced the DECISION span kind across the platform. - Datagen: Updated recorded applications to send each to its own project. - Bug Fixes: Ensured the external resources flag is properly honored for WASM and UI. - Documentation: Removed legacy evaluation cookbooks.

## Recommended actions
- Upgrade arize-phoenix to v20.19.0 to utilize the new DECISION span kind in tracing.
- Verify project routing behavior if using datagen to record applications.
- Review internal references to deprecated evaluation cookbooks.

## 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.