Imp.ext

Exchange-specific extensions for this impression. The spec defines nothing inside it, so field names and meanings come from each exchange's documentation.

CurrentobjectOptionalSince 2.0

Field facts

Path: imp.ext
Object: Imp
Type: object
Requirement: Optional
Added: OpenRTB 2.0
Spec section: 3.2.4

How it is used

Prebid Server, for example, carries bidder parameters under imp.ext.prebid.bidder. When a standard field exists for a signal, send it there as well; buyers that read only the standard field will miss a value that lives only in ext.

Example

Where the field sits in a payload, with everything else left out:

{
  "id": "req-1",
  "imp": [
    {
      "ext": {}
    }
  ]
}

Version history

Added in OpenRTB 2.0, and present in the latest snapshot. The table shows how each version's spec text types the field.

Versions	Type in the spec	Required	Deprecated
2.0	object	No	No
2.1	object	No	No
2.2	object, default - ma ag Op su st sp	No	No
2.3 to 2.4	object	No	No
2.5 to 2.6-202606	object	No	No

Other Imp fields

For a walkthrough of the whole object, read Bid request anatomy.