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

# milestone_reached Event

> Track when a key milestone is achieved.

Fires when a key milestone is achieved. Use this event to celebrate customer success and trigger engagement flows.

## JavaScript

```javascript theme={null}
window._upstack('track', 'milestone_reached', {
  accountId: 'acct_abc123',
  milestoneId: 'milestone_100_orders',
  milestoneName: '100 Orders Processed',
  milestoneValue: 100
});
```

## Properties

| Property       | Type   | Required | Description            |
| -------------- | ------ | -------- | ---------------------- |
| accountId      | string | Yes      | Account identifier     |
| milestoneId    | string | Yes      | Milestone identifier   |
| milestoneName  | string | No       | Milestone display name |
| milestoneValue | number | No       | Numeric value achieved |

## When to Fire

* When usage threshold is crossed
* When achievement is unlocked
* When significant product milestone occurs