fix(provider/xai): surface full xai error detail in APICallError.message

[dancer]

background

xai 4xx errors surfaced as opaque APICallError.message = "Bad Request" regardless of what xai actually returned. the real detail was always in responseBody but never in message, making errors hard to diagnose at a glance.

summary

the error schema in packages/xai/src/xai-error.ts only matched the OpenAI-style shape {error: {message, type, ...}}. xai's Responses API (and Chat Completions, per live testing) returns {code, error: string}, which fails schema validation and causes createJsonErrorResponseHandler to fall back to HTTP statusText.

fix: schema is now a union of both shapes, and errorToMessage extracts the appropriate field per variant.

follow-ups

• backport to release-v6.0 and release-v5.0

[vercel]

Additional Suggestion:

TypeScript compilation error: accessing .error.message on XaiErrorData fails because .error can now be a string after the schema was changed to a union type.

[github-actions]

🚀 Published in:

Package	Version
ai	7.0.0-canary.142 github npm
@ai-sdk/angular	3.0.0-canary.142 github npm
@ai-sdk/langchain	3.0.0-canary.142 github npm
@ai-sdk/llamaindex	3.0.0-canary.142 github npm
@ai-sdk/otel	1.0.0-canary.88 github npm
@ai-sdk/react	4.0.0-canary.143 github npm
@ai-sdk/rsc	3.0.0-canary.143 github npm
@ai-sdk/svelte	5.0.0-canary.142 github npm
@ai-sdk/vue	4.0.0-canary.142 github npm
@ai-sdk/workflow	1.0.0-canary.59 github npm
@ai-sdk/xai	4.0.0-canary.64 github npm