Bid.api

A single API framework required by the markup, from the API Frameworks list. Added in 2.4 and deprecated in 2.6 in favor of Bid.apis.

Deprecated since 2.6-202204integerOptionalSince 2.4

Field facts

Older bidders still send it. A 2.6 sender should fill apis, and may keep api with a consistent value while partners migrate.

Value	Meaning
`1`	VPAID 1.0: VPAID 1.0, the first interactive video ad interface; superseded by VPAID 2.0 and rare in current players.
`2`	VPAID 2.0: VPAID 2.0, still listed by some web players but not runnable on most CTV and app players.
`3`	MRAID 1.0: MRAID 1.0 for in-app rich media; labeled MRAID until OpenRTB 2.2 renamed it MRAID-1.
`4`	ORMMA: ORMMA, an early open in-app rich media interface that MRAID replaced.
`5`	MRAID 2.0: MRAID 2.0, added in OpenRTB 2.2, with resizing, video playback, and other container features.
`6`	MRAID 3.0: MRAID 3.0, added in OpenRTB 2.5, with exposure and audio events for in-app measurement.
`7`	OMID 1.0: OMID 1.0: the player or SDK integrates the Open Measurement SDK for verification.
`8`	SIMID 1.0: SIMID 1.0, the interactive layer for video ads that replaced VPAID interactivity. An AdCOM addition.
`9`	SIMID 1.1: SIMID 1.1, a later version of the interactive video interface. An AdCOM addition.
`500+`	Vendor-specific codes: Vendor-specific frameworks, meaningful only between partners that agreed on them in advance.

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

{
  "seatbid": [
    {
      "bid": [
        {
          "api": 5
        }
      ]
    }
  ]
}

Added in OpenRTB 2.4, deprecated in 2.6-202204, 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
2.4 to 2.5	integer	No	No
2.6-202210 to 2.6-202501	integer	No	Yes
2.6-202505 to 2.6-202606	integer	No	Yes

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