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

# Control visitors

> Visitor count for the control experience.

| Contract           | Value                            |
| ------------------ | -------------------------------- |
| Metric key         | `experiment_os.control_visitors` |
| Source             | Experiment OS                    |
| Status             | active                           |
| Type               | application                      |
| Semantic version   | Application calculation          |
| Catalog visibility | Supporting or fixed-surface only |

## How it's calculated

```sql theme={null}
Stored value = cro_experiments.control_users.
```

### Built from

* `Manual input or approved linked-result projection`

## Known caveats

None.

## Where this appears

* Experiment detail Results tab
* Experiment OS computed result fields

<AccordionGroup>
  <Accordion title="Grain and identity" icon="ruler">
    One Aloftly experiment record.

    **Join and identity keys**

    * org\_id
    * store\_id
    * experiment id
  </Accordion>

  <Accordion title="Filters and boundaries" icon="filter">
    * Tenant scope is enforced by the experiment row.
  </Accordion>

  <Accordion title="Timezone, currency, and freshness" icon="clock">
    **Timezone.** Not applicable.

    **Currency.** Not applicable.

    **Freshness.** Changes only when an authorized save or approved Intelligems projection updates the experiment.
  </Accordion>

  <Accordion title="Version history" icon="clock-rotate-left">
    | Date       | Change                                               |
    | ---------- | ---------------------------------------------------- |
    | 2026-07-02 | Established the Experiment OS result-input contract. |
  </Accordion>
</AccordionGroup>