Bid.adm

The ad markup, sent in the bid so the exchange can serve it if the bid wins: HTML for banners, a VAST document for video and audio, or a native response for native. If both adm and the win notice supply markup, adm takes precedence.

CurrentstringOptionalSince 2.0

Field facts

Path: seatbid.bid.adm
Object: Bid
Type: string
Requirement: Optional
Added: OpenRTB 2.0
Spec section: 4.2.3

How it is used

Markup in the bid avoids an extra HTTP call after the win, which lowers the risk of forfeiting a won impression. The exchange substitutes macros inside the markup as well as in notice URLs. Native markup goes in as a JSON-encoded string, encoded exactly once. Declare what the markup is in Bid.mtype.

Example

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

{
  "seatbid": [
    {
      "bid": [
        {
          "adm": "<a href='https://brand.example/'><img src='https://cdn.dsp.example/cr-5521.png' width='300' height='250'></a>"
        }
      ]
    }
  ]
}

Common mistakes

Native JSON encoded twice, so adm decodes to another string (openrtb.bid.adm.double_encoded).
A URL to a VAST file instead of the VAST XML itself (openrtb.bid.adm.not_markup). Put the document inline, or serve it through Bid.nurl.
Markup that contradicts Bid.mtype, such as HTML on a video bid (openrtb.bid.adm.markup_type_mismatch).

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 to 2.2	string	No	No
2.3 to 2.6-202606	string	No	No

Related fields

Other Bid fields

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