[BUG] Ultra AI Subscriber - 15-20 times of HTTP 503 Service Unavailable for one request

[evjanich]

Good day!
While on the Ultra AI subscription, I constantly encounter the error “Our servers are experiencing high traffic right now, please try again in a minute.”

Theoretically, shouldn’t this be avoided with an Ultra AI subscription? Or am I missing something?
Is there any way to resolve this issue?

Trajectory ID: efd3a75b-b86d-4a71-
Error: HTTP 503 Service Unavailable
Sherlog: 
TraceID: 0xb2dee47
Headers: {"Alt-Svc":["h3=\":443\"; ma=2592000,h3-29=\":443\"; ma=2592000"],"Content-Length":["429"],"Content-Type":["text/event-stream"],"Date":["Thu, 19 Mar 2026 12:03:36 GMT"],"Server":["ESF"],"Server-Timing":["gfet4t7; dur=1576"],"Vary":["Origin","X-Origin","Referer"],"X-Cloudaicompanion-Trace-Id":["b2dee474f04a82ca"],"X-Content-Type-Options":["nosniff"],"X-Frame-Options":["SAMEORIGIN"],"X-Xss-Protection":["0"]}

{
  "error": {
    "code": 503,
    "details": [
      {
        "@type": "type.googleapis.com/google.rpc.ErrorInfo",
        "domain": "cloudcode-pa.googleapis.com",
        "metadata": {
          "model": "claude-opus-4-6-thinking"
        },
        "reason": "MODEL_CAPACITY_EXHAUSTED"
      }
    ],
    "message": "No capacity available for model claude-opus-4-6-thinking on the server",
    "status": "UNAVAILABLE"
  }
}

[Abhijit_Pramanik]

Hello @evjanich,

We’re finding new ways to share more capacity with the Antigravity community. During windows where we have unused capacity, currently in the late afternoon PST, you’ll notice that your baseline quota stretches further. You’ll get more requests and less downtime within your existing plan.

As global demand shifts, we’ll continue to adjust these windows to pass any available capacity back to you. We’re committed to expanding access and ensuring every developer has the capacity they need to keep building.

[evjanich]

Question: are you absolutely sure that this is normal Antigravity performance on an Ultra AI subscription?