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

# HTTP scale API

An HTTP scale target lets Arklow observe and change a platform through an API you expose. The same status endpoint supports two write modes.

<Columns cols={2}>
  <Card title="Autoscaler floor" icon="arrows-up-down" href="/resources/scale-targets/http/floor">
    Update the range used by your platform's autoscaler.
  </Card>

  <Card title="Desired count" icon="hashtag" href="/resources/scale-targets/http/desired">
    Request a concrete replica count from your platform.
  </Card>
</Columns>

## Endpoint and authentication

Set **Endpoint** to the HTTPS base URL of your scale API, such as `https://scale.example.com`. Arklow appends the status path and the selected write path to this URL.

The endpoint must resolve to a publicly reachable address. Local and private-network addresses are rejected.

Use an [HTTP Auth Headers credential](/resources/credentials/http/auth-headers) for bearer tokens, API keys, or other headers your API expects. The same headers accompany observations and writes.

## Status endpoint

Arklow observes both modes with:

```http theme={null}
GET {endpoint}/scale/status
```

Return `200` with a JSON object:

```json theme={null}
{
  "current_replicas": 3,
  "settled": true
}
```

| Field              | Type    | Meaning                                                                               |
| ------------------ | ------- | ------------------------------------------------------------------------------------- |
| `current_replicas` | integer | The live replica count currently reported by the platform.                            |
| `settled`          | boolean | Whether the previous change has finished converging. Defaults to `true` when omitted. |

Both fields are optional. Return the values your platform can observe consistently. `settled: false` defers another write while the previous change converges.

## Write responses

A `2xx` response accepts a write. If the response includes a string `state`, Arklow records it as the write outcome.

A `4xx` response records a refusal. You can include an `error` string in the JSON body to describe the reason. Server errors and network failures appear as target errors.

Your endpoints should handle repeated writes of the same value safely. Retries and provider-side drift can cause Arklow to apply an accepted setting again.