> ## 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 message changed

> Run an automation when a Slack message is edited.

`slack.onMessageChanged` emits Slack `message_changed` events visible to the bot.

```ts automations/watch-slack-edits.automation.ts theme={null}
import { automation } from "automate.ax"
import { slack } from "automate.ax/slack"

export default automation("Watch Slack edits", () => {
  const change = slack.onMessageChanged()
  // Compare change.previousMessage with change.message to update a mirror.
})
```

The result includes the current `message`, `previousMessage`, conversation metadata, the typed original `event`, and the complete `envelope`.