AdCP — Video Ads

AdCP separates hosted video bytes (video_hosted) from VAST delivery (video_vast). Placement position such as pre-roll or mid-roll belongs on the product/placement, while the creative declaration describes the accepted payload.

Hosted video

{
  "format_option_id": "preroll_30s_hosted",
  "format_kind": "video_hosted",
  "params": {
    "width": 1920,
    "height": 1080,
    "duration_ms_exact": 30000,
    "containers": ["mp4"],
    "video_codecs": ["h264"],
    "audio_codecs": ["aac"],
    "max_file_size_kb": 51200,
    "slots": [
      { "asset_group_id": "video_main", "asset_type": "video", "required": true },
      { "asset_group_id": "landing_page_url", "asset_type": "url", "required": false }
    ]
  }
}

{
  "format_kind": "video_hosted",
  "assets": {
    "video_main": {
      "asset_type": "video",
      "url": "https://cdn.acmeoutdoor.example/trail-pro-30s.mp4",
      "width": 1920,
      "height": 1080,
      "duration_ms": 30000,
      "container_format": "mp4",
      "codec": "h264"
    }
  }
}

VAST

{
  "format_kind": "video_vast",
  "params": {
    "duration_ms_range": [15000, 30000],
    "vast_versions": ["3.0", "4.0", "4.1", "4.2"],
    "slots": [{ "asset_group_id": "vast_tag", "asset_type": "vast", "required": true }]
  }
}

Use a vast asset with either a URL or inline XML according to the selected declaration. The seller validates wrapper depth, media files, duration, macros, and supported VAST features.

VAST Validation

Format-layer validation of vast assets is structural: the manifest must satisfy the format’s requirements (today, vast_version), and validate_input checks manifest shape only. The VAST document itself is opaque at that level, so a structurally valid manifest can still carry an unplayable tag that fails silently at serve time. AdCP defines three validation levels for vast assets. Sellers declare the level they perform via creative_specs.vast_validation in get_adcp_capabilities; absent means structural. Validation runs at sync_creatives time, including dry_run. validate_input remains manifest-structure-only at every level.

Level	What the seller checks
`structural` (default)	Manifest shape and format `requirements` only. The VAST document is not inspected.
`document`	Everything in `structural`, plus the VAST document itself.
`wrapper`	Everything in `document`, plus wrapper-chain resolution.

Document-level validation. Sellers declaring document or wrapper:

MUST parse the document (inline content, or one response fetched from url) as XML and reject unparseable documents with VAST_PARSE_FAILED (error.details.reason: "not_xml").
MUST reject documents whose root element is not <VAST> with VAST_PARSE_FAILED (error.details.reason: "no_vast_root").
MUST reject documents whose <VAST version> attribute is missing or does not match the asset’s declared vast_version, the format’s vast_version requirement, or the seller’s declared creative_specs.vast_versions, with VAST_VERSION_MISMATCH (error.details.supported_versions lists the accepted versions).
SHOULD reject documents containing no <Ad> element, and <InLine> linear creatives carrying no <MediaFile>, with VAST_PARSE_FAILED (error.details.reason: "no_ad" / "no_media_file").
SHOULD verify that media, tracking, and click URLs use HTTPS.
MUST treat unresolved ad-server macros in URLs ([MACRO], ${MACRO}, {UNIVERSAL_MACRO}) as opaque tokens, never as validation failures. Macro correctness and substitution verification are out of scope for this contract.

Wrapper-chain validation. Sellers declaring wrapper additionally:

MUST resolve <Wrapper> redirects via <VASTAdTagURI> up to the format’s declared max_wrapper_depth (when present) and reject deeper chains with VAST_WRAPPER_DEPTH_EXCEEDED (error.details.reason: "depth").
MUST reject chains that revisit a <VASTAdTagURI> already seen (a loop) with VAST_WRAPPER_DEPTH_EXCEEDED (error.details.reason: "loop").
SHOULD apply a per-hop timeout, rejecting with VAST_WRAPPER_DEPTH_EXCEEDED (error.details.reason: "timeout"), and MUST fetch wrapper hops over HTTPS only.
MUST apply document-level checks to the terminal <InLine> document and reject with the corresponding document-level code on failure.

Preflight, not approval. A VAST endpoint can return a different document per request (decisioning, rotation, macros). Passing validation at sync time is a preflight of the tag’s shape at that moment, not a guarantee about future responses. Sellers MUST NOT treat a passing preflight as approval of all future responses and MAY re-validate during delivery. Sellers fetching url assets or wrapper hops SHOULD apply the same server-side request protections (private-address blocking, redirect and size limits) they apply to any other agent-supplied URL fetch. Error codes. In all cases error.field identifies the offending asset path in the manifest.

Code	Meaning
`VAST_PARSE_FAILED`	Document is not well-formed XML, has no `<VAST>` root, no `<Ad>`, or an inline linear creative has no `<MediaFile>`
`VAST_VERSION_MISMATCH`	Document’s `<VAST version>` disagrees with the declared `vast_version`, the format requirement, or the seller’s supported versions
`VAST_WRAPPER_DEPTH_EXCEEDED`	Wrapper chain exceeds `max_wrapper_depth`, loops, or a hop timed out

Vertical and flexible video

Vertical short video is still video_hosted; use width/height or aspect-ratio parameters and, for an exact publisher contract, {publisher_domain, format_option_id}. Equal canonical kind alone is not proof that a generic video builder satisfies a publisher’s duration, codec, slot, or composition constraints. See CTV, Canonical formats, and Creative manifests.

Getting Started

Building with AdCP

Protocol

Using AAO

FAQ

Trust & Security

Reference

Certification

Video Ads

Hosted video

VAST

VAST Validation

Vertical and flexible video

​Hosted video

​VAST

​VAST Validation

​Vertical and flexible video

Hosted video

VAST

VAST Validation

Vertical and flexible video