> ## Documentation Index
> Fetch the complete documentation index at: https://docs.adcontextprotocol.org/llms.txt
> Use this file to discover all available pages before exploring further.

# Implementing Standard Format Support

> How AdCP 3.2 sales agents declare standard creative acceptance with canonical product format options.

This guide is for sales agents declaring the creative contracts their inventory accepts. In AdCP 3.2, author canonical `Product.format_options[]`. `list_creative_formats`, recursive creative-agent catalogs, and compound named format IDs are deprecated compatibility surfaces.

## Choose the authority first

| Question                                         | Authoritative surface                                |
| ------------------------------------------------ | ---------------------------------------------------- |
| What does a publisher surface accept?            | Publisher `adagents.json.formats[]`                  |
| What can this seller deliver for a product?      | That product's closed `format_options[]` set         |
| Which creative agent can produce or validate it? | `get_adcp_capabilities.creative.supported_formats[]` |

The seller declares deliverability; it does not nominate a creative producer. Buyers can use the AgenticAdvertising.org registry to find creative agents whose self-declared canonical envelope satisfies the product declaration.

Zero registry matches is a valid result: it means no protocol-exposed build, validation, or preview service currently advertises that contract. The buyer may still supply an already-conforming finished manifest or use a seller-returned preview, but MUST NOT infer a renderer from the publisher or product format declaration.

## Standard formats

For standard display, video, audio, and native shapes, use the canonical `format_kind` and narrow it with explicit parameters and slots. Do not create a new identifier merely because your product has a different price or placement name.

```json theme={null}
{
  "product_id": "daily_pulse_homepage_display",
  "name": "Daily Pulse homepage display",
  "format_options": [
    {
      "format_option_id": "homepage_image_300x250",
      "format_kind": "image",
      "params": {
        "width": 300,
        "height": 250,
        "slots": [
          { "asset_group_id": "image_main", "asset_type": "image", "required": true },
          { "asset_group_id": "landing_page_url", "asset_type": "url", "required": true }
        ]
      }
    }
  ]
}
```

`format_options[]` is a closed set. A package or creative selector outside it must be rejected. Price, floor, availability, and deal eligibility stay on the product or pricing option, not in format parameters.

## Publisher-owned formats

When a product sells a publisher-catalog format, repeat its namespace and canonical declaration inline:

```json theme={null}
{
  "format_options": [
    {
      "publisher_domain": "shorts.streamhaus.example",
      "format_option_id": "vertical_video",
      "format_kind": "video_hosted",
      "params": {
        "width": 1080,
        "height": 1920,
        "duration_ms_range": [5000, 60000],
        "slots": [
          { "asset_group_id": "video_main", "asset_type": "video", "required": true }
        ]
      }
    }
  ]
}
```

Resolve the publisher's `/.well-known/adagents.json` first. If the publisher has not adopted AdCP, use an explicitly identified AgenticAdvertising.org community mirror. Do not promote one sales agent's product declaration into a publisher fact.

## Custom formats

Use `format_kind: "custom"` only when the structural creative contract cannot be expressed by a canonical kind. Supply both `format_shape` and an immutable, digest-pinned `format_schema`.

```json theme={null}
{
  "format_option_id": "homepage_takeover",
  "format_kind": "custom",
  "format_shape": "multi_placement_takeover",
  "format_schema": {
    "uri": "https://formats.daily-pulse.example/homepage-takeover.schema.json",
    "digest": "sha256:0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef"
  },
  "canonical_formats_only": true,
  "params": {}
}
```

## Multi-placement coverage

Product-level options are the upper bound. Placement-level options may narrow that set but cannot broaden it. For every included delivery placement, the selected package format set must have a non-empty compatible intersection. Reject or refine a package that cannot cover all included placements; never silently drop inventory.

## Finding a creative producer

Sales agents do not publish a recursive list of creative agents. A buyer can reverse-query the registry and then verify the selected agent directly:

```http theme={null}
GET /api/registry/agents?publisher_domain=shorts.streamhaus.example&format_option_id=vertical_video&creative_operation=build
```

The creative agent's `supported_formats[]` entry supplies its local `capability_id`. That string is passed to `build_creative.target_capability_id`; it is never copied onto the product or returned manifest.

## 3.x compatibility

A 3.2 seller may project canonical declarations into deprecated `format_ids[]` for an older peer. When both fields are emitted, they must describe the same underlying contracts and canonical fields win. Do not independently author or extend the legacy catalog.

## Related documentation

* [Canonical formats](/dist/docs/3.2.0-beta.0/creative/canonical-formats)
* [Media products](/dist/docs/3.2.0-beta.0/media-buy/product-discovery/media-products)
* [Creative-agent capabilities](/dist/docs/3.2.0-beta.0/protocol/get_adcp_capabilities)
* [Deprecated `list_creative_formats`](/dist/docs/3.2.0-beta.0/creative/task-reference/list_creative_formats)