> ## Documentation Index
> Fetch the complete documentation index at: https://docs.automate.ax/llms.txt
> Use this file to discover all available pages before exploring further.

> ## Agent Instructions
> Automate.ax automations are TypeScript programs.
> Use Bun for installation and command examples.
> Use Automate.ax for the product name and automate.ax for the package, CLI, and domain.
> Treat documented public APIs as current; do not invent transitional or deprecated names.

# On Vercel deployment rollback

> Run an automation when Vercel reports deployment rollback.

`vercel.onDeploymentRollback` starts an automation for the corresponding Vercel webhook event.

```ts automations/on-deployment-rollback.automation.ts theme={null}
import { automation } from "automate.ax"
import { vercel } from "automate.ax/vercel"

export default automation("On Vercel deployment rollback", () => {
  const event = vercel.onDeploymentRollback()
  event.transform(({ payload }) => ({
    from: payload.fromDeploymentId,
    to: payload.toDeploymentId,
  }))
})
```

## Input

The trigger accepts optional static `account` selection. Without it, Automate.ax uses the project's Vercel OAuth binding.

## Output

The event includes `id`, `createdAt`, `region`, its exact `type` discriminator, and a typed `payload`. `payload.fromDeploymentId` is replaced by `payload.toDeploymentId`; `payload.project.id` identifies the project.

## Provider behavior

Automate.ax verifies Vercel's signature, routes the event to the matching installation, and deduplicates the delivery by event ID. The event confirms that Vercel accepted the rollback. Traffic may still be switching.