Verified history
This means HyperObserve has not found sufficient first-party evidence for a dated before-and-after event. It does not mean Fly.io has never changed. Undated values are kept in the current baseline below instead of being presented as history.
Current monitored baseline
HyperObserve currently monitors 4 scoped observations for Fly.io. The baseline covers Machines API action rate, persistent volume size, snapshot retention, ephemeral root performance. Each value retains its plan, product, endpoint, region, account, or runtime qualifier so a future change can be compared against the correct scope.
| 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 |
| persistent volume sizeA volume can attach to only one Machine at a time. | 1 GB default; 500 GB maximum | Per volume | Fly.ioAug 22, 2026 |
| snapshot retentionSnapshots are a recovery feature and remain tied to volume behavior. | 5 days default; configurable 1–60 days | Fly Volumes | Fly.ioAug 22, 2026 |
| ephemeral root performanceThe root filesystem is ephemeral and has different durability from a Fly Volume. | Up to 2,000 IOPS and 8 MiB/s | Machine root filesystem | Fly.ioAug 22, 2026 |
Tracked constraints and impact
Machines API rates, volume sizes, snapshots, and ephemeral disk constraints. A change is recorded only when it alters a constraint developers can act on, such as capacity planning, request shaping, model selection, deployment configuration, storage design, retry behavior, or account budgeting.
Fly Machines API Rate Limits
Fly Machines API Rate Limits, verified against Fly.io's official documentation with scope, implementation impact, caveats, and a direct check.
Fly Volume Size Limits
Fly Volume Size Limits, verified against Fly.io's official documentation with scope, implementation impact, caveats, and a direct check.
Fly Volume Snapshot Retention
Fly Volume Snapshot Retention, verified against Fly.io's official documentation with scope, implementation impact, caveats, and a direct check.
Fly Machine Ephemeral Disk Limits
Fly Machine Ephemeral Disk Limits, verified against Fly.io's official documentation with scope, implementation impact, caveats, and a direct check.
How a change is verified
- Compare the current first-party statement with the previously stored observation, including the exact plan, model, runtime, endpoint, region, and account scope.
- Separate a true product change from documentation clarification, temporary capacity, configurable account state, or a limit that applies to a different execution path.
- Preserve the old and new values, official source, effective date when disclosed, detection date, and practical impact. If those elements cannot be supported, no historical event is published.
Official sources monitored
These first-party documents support the current Fly.io baseline. HyperObserve links directly to them so you can confirm the live wording before making a production decision.
Machines API request rates and bursts
Volume size, attachment, snapshots, and ephemeral disk performance