Quick answer
Fly.io documents machines api action rate as Most actions: 1 request/second with burst 3. Read operations and app deletion have separate documented rates.
Verified Aug 22, 2026Official source
Current limits
| Constraint | Current value | Scope | Verified source |
|---|---|---|---|
| Machines API action rateRead operations and app deletion have separate documented rates. | Most actions: 1 request/second with burst 3 | Per API action scope | Fly.ioAug 22, 2026 |
Why does this limit matter?
A deployment controller can be throttled by control-plane calls even when Machines are healthy.
This value is scoped to Per API action scope; a different plan, runtime, model, endpoint, region, or account can produce a different effective constraint.
What should you check?
- Group metrics by API action and implement queueing for create, update, and start calls.
- Confirm the exact plan, model, runtime, endpoint, region, and account that serve the failing workload.
- Record the observed value, response headers or configuration, timestamp, and source without logging secrets.
Important caveats
- The limits apply to Machines API operations, not application request traffic.
- Treat the official source and live account configuration as authoritative if they differ from this verified snapshot.
HyperObserve reports the documented platform constraint. Your application, SDK, gateway, provider, region, or account can impose a lower effective limit.
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