OTA Updates

What OTA updates are#

Over-the-air (OTA) updates ship a new JavaScript bundle to installed apps without going through an app store. The device polls for a newer bundle, downloads it, applies it atomically, and — if the new bundle misbehaves — reverts to the one it replaced. The native binary never changes; only the JS layer does, which is why a fix can reach users in minutes instead of a store review cycle.

How a release reaches a device#

1. Publish. You build a bundle and publish it to a channel — from the CLI (scalebun ota publish) or by uploading in this area. Bundles are compiled to Hermes bytecode by default (--hermes); pass --hermes-disabled to ship plain JS.

2. Check. Each device asks the server whether a newer bundle exists for its app version, platform and channel. The server answers with one of three actions: do nothing, download a named bundle, or roll back.

3. Download and stage. The device fetches the bundle — a binary patch against the current bundle when one is available, a full download otherwise — verifies it (SHA-256, and an optional ed25519 signature), and stages it alongside the running one.

4. Apply. The staged bundle is promoted in an atomic slot swap: the new bundle becomes current, the old one becomes previous. Depending on the release's install mode the app restarts immediately, on next restart, or on next resume.

5. Recover. If the new bundle crashes on boot, the device reverts to previous on the next cold start on its own — no server round-trip required.

The pages in this area#

• Channels & Releases — publish, promote and roll back bundles, and manage the channels they target.

• Adoption — how many devices downloaded and installed each release.

• Health — whether a release is stable, compared against the one before it.

• Guards & Targeting — automatic rules that pause or roll back a bad release, and the rules that decide which devices get one.

• Settings & Keys — signing keys, test tokens, and your bundle and storage usage.

Manage#

Configure#