AdCP Creative Protocol

This skill enables you to execute the AdCP Creative Protocol with creative agents. Use get_adcp_capabilities, list_transformers, build_creative, and preview_creative exposed by the connected agent. In AdCP 3.2, list_creative_formats is deprecated and must not drive a new workflow.

Buyer-side basics — idempotency replay, oneOf variants, async status:'submitted' polling, error recovery from adcp_error.issues[] — live in skills/call-adcp-agent/SKILL.md. This skill covers per-task semantics only.

Overview

The Creative Protocol provides standardized discovery, build, and preview tasks:

Task	Purpose	Response Time
get_adcp_capabilities	Discover canonical creative capabilities	~1s
list_transformers	Discover selectable production services	~1s
build_creative	Generate or transform creatives	~30s-5m
preview_creative	Get visual previews	~5s
get_creative_delivery	Variant-level delivery data	~5-30s

Typical Workflow

1. Discover capabilities: read get_adcp_capabilities.creative.supported_formats[]
2. Build creative: build_creative to generate or transform a manifest
3. Preview: preview_creative to see how it renders
4. Sync: Use sync_creatives (media-buy task) to traffic the creative

---

Canonical formats (AdCP 3.2)

Products and manifests use 15 canonical format_kind values: image, html5, display_tag, image_carousel, video_hosted, video_vast, audio_hosted, audio_vast, audio_daast, sponsored_placement, native_in_feed, responsive_creative, agent_placement, seller_rendered_stateful_display, and coordinated_placements. Use custom only for a shape outside those canonicals, with required format_shape and format_schema.

A ProductFormatDeclaration carries:

• format_kind: the canonical (discriminator)
• params: per-canonical parameters narrowing the format (dimensions, durations, codecs, char limits, CTA enums, sizes[], etc.)
• Optional format_option_id: stable product/publisher option identifier when declarations need routing
• Optional v1_format_ref: [{agent_url, id}]: always an array — links this v2 declaration to one or more v1 named formats. Multi-size declarations should carry one ref per size in sizes[].
• Optional seller_preference: "preferred" | "accepted" | "discouraged": soft routing hint when a product carries multiple format_options

Where to declare a format:

Where	When to use
adagents.json top-level formats[] (publisher catalog)	Format shared across many sellers of the same publisher inventory; declares the publisher-authoritative shape once
Product.format_options[] (inline on a product)	Seller-specific accepted set. Reference a publisher declaration with {publisher_domain, format_option_id} when applicable
Placement.format_options[] (format_option_id reference or inline)	Tying a publisher placement to accepted publisher formats
get_adcp_capabilities.creative.supported_formats[]	What a creative agent can build, validate, or preview; every entry has an agent-local capability_id

Size flexibility (image / html5 / display_tag): exactly one of three modes — width+height (fixed), sizes: [{w,h}] (multi-size, mirrors OpenRTB banner.format[]), or min_width/max_width/min_height/max_height (responsive).

Publisher catalog resolution: call GET https://agenticadvertising.org/api/registry/publisher?domain=<publisher_domain> for the complete publisher-origin → AgenticAdvertising.org community-catalog → fail-closed resolution order and provenance. Add &include=placements for provenance-labeled placement summaries with resolved canonical format options. The top-level formats[] remains a lossy display summary; fetch the raw URL returned in files.adagents_json.registry_url or hosting.resolved_url / hosting.expected_url for custom-format validation and omitted declaration fields. Do not synthesize publisher authority from a sales or creative agent.

Conversion tracking is NOT a creative-format concern. Pixel-firing, conversion events, and attribution belong on sync_event_sources / event_log (campaign-scoped). Don't stuff pixel_id into platform_extensions on a format declaration.

See docs/creative/canonical-formats.mdx for the full vocabulary, narrowing rules, error-code surface, and worked examples (Meta Reels, IAB display, host-read podcast, generative DSP).

---

Task Reference

get_adcp_capabilities

Discover this creative agent's canonical operations.

Request:

{ "protocols": ["creative"] }

Response contains:

• creative.supported_formats[]: entries with stable, catalog-unique capability_id, canonical format, and operations; preview support is declared by operations containing preview
• capability flags such as supports_generation and supports_transformers

---

build_creative

Generate a creative from scratch or transform an existing creative to a different format.

Pure Generation (from brief):

{
  "message": "Create a banner promoting our winter sale with a warm, inviting feel",
  "target_capability_id": "winter_banner_300x250",
  "idempotency_key": "1db179c8-09c8-4eb3-9b96-ae741acdaf1f",
  "brand": {
    "domain": "mybrand.com"
  }
}

Transformation (resize/reformat):

{
  "message": "Adapt this leaderboard to a 300x250 banner",
  "creative_manifest": {
    "format_kind": "image",
    "assets": {
      "image_main": {
        "asset_type": "image",
        "url": "https://cdn.mybrand.com/leaderboard.png",
        "width": 728,
        "height": 90
      },
      "landing_page_url": {
        "asset_type": "url",
        "url": "https://mybrand.com/spring-sale"
      }
    }
  },
  "target_capability_id": "banner_resize_300x250",
  "idempotency_key": "4c052b08-2e5f-4a66-b0c0-57c199302411"
}

Key fields:

• message (string, optional): Natural language instructions for generation/transformation
• creative_manifest (object, optional): Source manifest - minimal for generation, complete for transformation
• target_capability_id (string): One output advertised by this agent; use target_capability_ids[] for multiple outputs

Response contains:

• creative_manifest: Complete manifest ready for preview_creative or sync_creatives

---

preview_creative

Generate visual previews of creative manifests.

Single preview:

{
  "request_type": "single",
  "creative_manifest": {
    "format_kind": "image",
    "assets": {
      "image_main": {
        "asset_type": "image",
        "url": "https://cdn.example.com/banner.png",
        "width": 300,
        "height": 250
      }
    }
  }
}

With device variants:

{
  "request_type": "single",
  "creative_manifest": { /* includes format_kind, assets */ },
  "inputs": [
    { "name": "Desktop", "macros": { "DEVICE_TYPE": "desktop" } },
    { "name": "Mobile", "macros": { "DEVICE_TYPE": "mobile" } }
  ]
}

Batch preview (5-10x faster):

{
  "request_type": "batch",
  "requests": [
    { "creative_manifest": { /* creative 1 */ } },
    { "creative_manifest": { /* creative 2 */ } }
  ]
}

Key fields:

• request_type (string, required): "single" or "batch"
• creative_manifest (object, required): Complete creative manifest
• inputs (array, optional): Generate variants with different macros/contexts
• output_format (string, optional): "url" (default) or "html"

Response contains:

• previews: Array of preview objects with preview_url or preview_html
• expires_at: When preview URLs expire

---

get_creative_delivery

Retrieve variant-level creative delivery data from a creative agent. Returns what was generated, served, and how each variant performed.

Request:

{
  "media_buy_ids": ["mb_abc123"],
  "start_date": "2025-01-01",
  "end_date": "2025-01-31",
  "max_variants": 10
}

Key fields:

• media_buy_ids (array, optional): Filter to specific media buys
• creative_ids (array, optional): Filter to specific creatives
• start_date, end_date (string, optional): Delivery period (YYYY-MM-DD)
• max_variants (integer, optional): Max variants per creative (useful for generative creatives)
• account (object, optional): Account for routing and scoping

At least one scoping filter (media_buy_ids or creative_ids) is required.

Response contains:

• creatives: Array with variant-level delivery data
  • variant_id: Unique variant identifier (use in preview_creative with request_type: "variant")
  • generation_context: What triggered this variant (page topic, device, etc.)
  • delivery_metrics: Impressions, clicks, completions
  • ext: Platform engagement metrics (likes, shares, comments)

---

Key Concepts

Capability IDs and canonical manifests

A creative agent's capability_id is a local operation selector:

{
  "target_capability_id": "winter_banner_300x250"
}

It is never copied into a product or manifest. The resulting manifest is portable and carries the canonical format contract:

Creative Manifests

Manifests pair format specifications with actual assets:

{
  "format_kind": "image",
  "assets": {
    "banner_image": {
      "asset_type": "image",
      "url": "https://cdn.example.com/banner.png",
      "width": 300,
      "height": 250
    },
    "headline": {
      "asset_type": "text",
      "content": "Shop Now"
    },
    "clickthrough_url": {
      "asset_type": "url",
      "url": "https://brand.com/sale"
    }
  }
}

Asset Types

Common asset types:

• image: Static images (JPEG, PNG, WebP)
• video: Video files (MP4, WebM) or VAST tags
• audio: Audio files (MP3, M4A) or DAAST tags
• text: Headlines, descriptions, CTAs
• html: HTML5 creatives or third-party tags
• javascript: JavaScript tags
• url: Tracking pixels, clickthrough URLs

Brand identity

For generative creatives, provide brand context by domain:

{
  "brand": {
    "domain": "acmecorp.com"
  }
}

The agent resolves the domain to retrieve the brand's identity (name, colors, guidelines, etc.) from its brand.json file.

Generative vs Transformation

• Pure Generation: Provide target_capability_id, brand, and a natural language message. The creative agent generates all output assets from scratch.
• Transformation: Complete manifest with existing assets. Creative agent adapts to target format, following message guidance.

---

Error Handling

Common error patterns:

• 400 Bad Request: Invalid manifest or capability selector
• 404 Not Found: Capability not supported by this agent
• 422 Validation Error: Manifest doesn't match format requirements

Error responses include:

{
  "error": {
    "code": "FORMAT_NOT_SUPPORTED",
    "message": "target_capability_id is not advertised by this creative agent"
  }
}