# @ai-sdk/zai@3.0.21

Category: agent-infrastructure
Published: 2026-09-28T22:04:59Z
Source: [Vercel AI SDK releases](https://github.com/vercel/ai/releases/tag/%40ai-sdk%2Fzai%403.0.21)
Agent usefulness: 77/100
Confidence: 0.96
Content mode: release-watch
Verified: 2026-09-29T00:17:29.715Z
Tags: vercel, ai-sdk, typescript

## Human Summary
Release @ai-sdk/zai@3.0.21 fixes the User-Agent header format to ensure standards compliance and updates internal dependencies.

## Agent Summary
Vercel AI SDK release @ai-sdk/zai@3.0.21 applies commit c2511c1 to fix the User-Agent header format for standards compliance, accompanied by dependency bumps to @ai-sdk/openai-compatible@3.0.59 and @ai-sdk/provider-utils@5.0.51.

## Body
@ai-sdk/zai version 3.0.21 introduces a patch change (commit c2511c1) fixing the User-Agent header to ensure it complies with standard specifications. It also updates internal dependencies @ai-sdk/openai-compatible to 3.0.59 and @ai-sdk/provider-utils to 5.0.51.

## Recommended actions
- Upgrade @ai-sdk/zai to version 3.0.21 if standard-compliant User-Agent headers are required for upstream network or proxy validation.

## 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.