xAI (Grok): A priority service tier became available on text inference endpoints; priority rates are billed only when priority is applied.
Old No per-request priority tier (not stated)
New service_tier "priority" on Chat Completions and Responses; priority rates billed only when used (rate not stated in note)
Why it matters: If you are on or choosing a xAI API (Priority Processing) plan, this changes what the plan includes or how it is billed. The source does not state a separate effective date.
Alerts waitlist (not launched)
Joining sends nothing now; we keep your email only to tell you when alerts launch. Remove it any time: support@testedmcp.com. Stored by Netlify Forms. Privacy
| Product | xAI API (Priority Processing) |
|---|---|
| Category | plan |
| Announced / detected | 2026-06-15 Backfilled |
| Backfilled | Yes: added retroactively |
| Quote verified against | https://docs.x.ai/docs/release-notes |
| Effective | not stated in source |
| Before | No per-request priority tier (not stated) |
| After | service_tier "priority" on Chat Completions and Responses; priority rates billed only when used (rate not stated in note) |
| Official source | https://docs.x.ai/docs/release-notes |
| Source quote | priority rates are billed only when priority is used. |
| Archive | No post-change Wayback capture found |
| Snapshot hash | sha256:a6df9314ab169ab754e8355f373c58de0110bc351527728b73c7c653b1335bd2 |
| Status | verified |
All xAI (Grok) changes · Dispute or correct this entry
Previous changes from xAI (Grok)
- between 2026-09-28 and 2026-10-13 Backfilled: Per-second request limit formula loosened from RPM / 60 to RPM / 48 with a minimum of 2.
- between 2026-09-10 and 2026-09-28 Backfilled: Voice models brought under the spend-based rate limit tiers.
- 2026-09-02: grok-imagine-image-quality retires 2026-11-02; requests will be served by grok-imagine-image-2.0 (quality=low) at a lower per-image price.
- between 2026-06-15 and 2026-07-06 Backfilled: Request limits switched from requests per minute to requests per second, derived as RPM / 60.
- between 2026-04-02 and 2026-04-13 Backfilled: Rate limit tiers consolidated from six to five (Tier 0-4) with new spend thresholds.
- between 2026-03-13 and 2026-03-23 Backfilled: Spend-based rate limit tiers introduced for text models, unlocking automatically by cumulative spend since Jan 1 2026.
How xAI (Grok) limits and pricing work · All changes, June 2026