# arize-phoenix: v20.21.1

Category: safety-research
Published: 2026-10-12T21:09:18Z
Source: [Arize Phoenix releases](https://github.com/Arize-ai/phoenix/releases/tag/arize-phoenix-v20.21.1)
Agent usefulness: 62/100
Confidence: 0.96
Content mode: release-watch
Verified: 2026-10-13T00:17:36.667Z
Tags: observability, evaluation, tracing

## Human Summary
Arize Phoenix v20.21.1 includes bug fixes that improve span ingestion reliability and allow TraceDataset to accept empty DataFrames, along with documentation updates.

## Agent Summary
Arize Phoenix v20.21.1 patch release improves span ingestion reliability and resolves an issue in TraceDataset to accept empty DataFrames. Documentation was updated to include Scalekit and fix an 'Add to Cursor' MCP badge link.

## Body
Arize Phoenix v20.21.1 delivers bug fixes and documentation updates. Key fixes include improvements to span ingestion reliability and support for empty DataFrames within TraceDataset. Documentation additions include adding Scalekit to the platform documentation and making the 'Add to Cursor' MCP badge clickable in the README.

## Recommended actions
- Upgrade to arize-phoenix v20.21.1 if experiencing span ingestion instability or errors when passing empty DataFrames to TraceDataset.

## 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.