App Open Signal

OpenRTB imp.ext.cloudx.format flag that identifies App Open inventory

CloudX marks App Open inventory on eligible outbound OpenRTB requests with imp.ext.cloudx.format set to app_open. Read this flag to distinguish App Open from interstitial traffic. Its standard media shape otherwise matches an interstitial.

Where to read it

Path	Value
`imp[].ext.cloudx.format`	`"app_open"` on App Open impressions

CloudX stamps the cloudx object on the outbound OpenRTB copy of each eligible impression. It is read-only for demand partners.

Request shape

App Open impressions are otherwise identical to interstitial impressions:

imp[].instl is 1.
imp[].banner carries fullscreen dimensions derived from the device screen.

Do not rely on instl or banner size to identify App Open. Read imp.ext.cloudx.format instead.

Format values

format is a string from the CloudX ad-format vocabulary. app_open is the only value sent today; CloudX may use the same field to identify other formats in the future. Ignore values you do not recognize.

Example

{
  "imp": [
    {
      "id": "1",
      "instl": 1,
      "banner": {
        "w": 390,
        "h": 844,
        "format": [{ "w": 390, "h": 844 }],
        "pos": 7
      },
      "ext": {
        "cloudx": {
          "format": "app_open"
        }
      }
    }
  ]
}

Response creative type

The request is banner-shaped even when your endpoint is enabled to return VAST. For an App Open VAST response, set bid.ext.crtype: "vast"; on OpenRTB 2.6 also set bid.mtype: 2. Do not rely on inference from the request’s banner object.

Availability

No payload-level opt-in is required. App Open eligibility and supported creative types remain endpoint or account configuration confirmed during onboarding. CloudX stamps the flag after constructing each eligible endpoint request.