> ## 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 thread reply posted

> Run an automation when someone replies in a Slack thread.

`slack.onThreadReplyPosted` emits ordinary user-authored messages whose `threadTimestamp` differs from their own `timestamp`. Bot, app, system, edit, and delete messages are excluded.

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

export default automation("Watch Slack replies", () => {
  const reply = slack.onThreadReplyPosted()
  // Use reply.threadTimestamp to attach the reply to its Slack thread.
})
```

The result includes optional `text`, `timestamp`, `threadTimestamp`, `userId`, literal `conversationType`, the typed original `event`, and the complete `envelope`.