Preset xai builds the OpenAI-compatible adapter against the fixed base URL https://api.x.ai/v1 with a required API key and no extra headers. It defaults to json_schema structured output and lets the household select json_object as a fallback; a request is never retried in another mode. Migration 0005_ai_provider_xai rebuilds ai_settings and ai_runs the 0004 way so their provider CHECK also accepts xai, keeping every 0004 value. Maestro task d8be638f-297f-4b7a-a545-74d193055904. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>