build_creative

Transform or generate a creative manifest for a specific format. This task takes a source manifest (which may be minimal for pure generation) and produces a target manifest in the specified format. Key concept: build_creative is fundamentally a transformation - it takes a creative manifest as input and produces a creative manifest as output. For pure generation (creating from scratch), the source manifest is minimal (just format and seed assets). For transformation (e.g., resizing, reformatting), the source is a complete creative. For information about format IDs and how to reference formats, see Creative Formats - Referencing Formats.

Request Parameters

Parameter	Type	Required	Description
`message`	string	No	Natural language instructions for the transformation or generation. For pure generation, this is the creative brief. For transformation, this provides guidance on how to adapt the creative.
`creative_manifest`	object	No	Creative manifest to transform or generate from (see Creative Manifest). For pure generation, this should include the target format_id and any required input assets (e.g., `promoted_offerings` for generative formats). For transformation, this is the complete creative to adapt.
`target_format_id`	object	Yes	Format ID to generate. Object with `agent_url` and `id` fields. The format definition specifies required input assets.

Important: Required inputs like promoted_offerings should be included in the creative_manifest.assets object, not as separate task parameters. The format definition specifies what assets it requires.

Use Cases

Pure Generation (Creating from Scratch)

For pure generation, provide a minimal source manifest with the required input assets defined by the format:

{
  "message": "Create a banner promoting our winter sale with a warm, inviting feel",
  "target_format_id": {
    "agent_url": "https://creative.adcontextprotocol.org",
    "id": "display_300x250_generative"
  },
  "creative_manifest": {
    "format_id": {
      "agent_url": "https://creative.adcontextprotocol.org",
      "id": "display_300x250_generative"
    },
    "assets": {
      "promoted_offerings": {
        "brand_manifest": {
          "url": "https://mybrand.com",
          "colors": {"primary": "#FF0000"}
        },
        "inline_offerings": [
          {
            "name": "Winter Sale Collection",
            "description": "50% off all winter items"
          }
        ]
      }
    }
  }
}

Transformation (Adapting Existing Creative)

For transformation, provide the complete source manifest:

{
  "message": "Adapt this creative for mobile, making the text larger and CTA more prominent",
  "creative_manifest": {
    "format_id": {
      "agent_url": "https://creative.adcontextprotocol.org",
      "id": "display_300x250"
    },
    "assets": {
      "banner_image": {
        "asset_type": "image",
        "url": "https://cdn.example.com/original-banner.png",
        "width": 300,
        "height": 250
      },
      "headline": {
        "asset_type": "text",
        "content": "Winter Sale - 50% Off"
      }
    }
  },
  "target_format_id": {
    "agent_url": "https://creative.adcontextprotocol.org",
    "id": "display_mobile_320x50"
  }
}

Format Resizing

Transform an existing creative to a different size:

{
  "creative_manifest": {
    "format_id": {
      "agent_url": "https://creative.adcontextprotocol.org",
      "id": "display_728x90"
    },
    "assets": { /* complete assets */ }
  },
  "target_format_id": {
    "agent_url": "https://creative.adcontextprotocol.org",
    "id": "display_300x250"
  }
}

Response Format

The response contains the transformed or generated creative manifest:

{
  "creative_manifest": {
    "format_id": {
      "agent_url": "https://creative.adcontextprotocol.org",
      "id": "display_300x250"
    },
    "promoted_offering": "Winter Sale Collection",
    "assets": {
      "banner_image": {
        "asset_type": "image",
        "url": "https://cdn.example.com/generated-banner.png",
        "width": 300,
        "height": 250
      },
      "headline": {
        "asset_type": "text",
        "content": "50% Off Winter Sale"
      },
      "clickthrough_url": {
        "asset_type": "url",
        "url": "https://mybrand.com/winter-sale"
      }
    }
  }
}

Field Descriptions

creative_manifest: The complete creative manifest ready for use with sync_creatives or preview_creative
format_id: The target format (matches target_format_id from request)
promoted_offering: Product/offering being advertised (optional)
assets: Map of asset IDs to actual asset content, matching the format’s assets_required specification

Workflow Integration

Typical Generation Workflow

Build: Use build_creative to generate/transform the manifest
Preview: Use preview_creative to see how it renders (see preview_creative)
Sync: Use sync_creatives to traffic the finalized creative

// Step 1: Build (generative format)
{
  "message": "Create a display banner for our winter sale",
  "target_format_id": {"agent_url": "...", "id": "display_300x250_generative"},
  "creative_manifest": {
    "format_id": {"agent_url": "...", "id": "display_300x250_generative"},
    "assets": {
      "promoted_offerings": {
        "brand_manifest": { /* brand data */ },
        "inline_offerings": [ /* products */ ]
      }
    }
  }
}

// Step 2: Preview (using the output manifest from step 1)
{
  "format_id": {"agent_url": "...", "id": "display_300x250"},
  "creative_manifest": {
    /* output from build_creative - includes all assets */
  },
  "inputs": [{"name": "Desktop view"}, {"name": "Mobile view"}]
}

// Step 3: Sync (if preview looks good)
{
  "creative_manifests": [{ /* approved manifest from build_creative */ }]
}

Key insight: The manifest carries everything. promoted_offerings (if required by the format) is included in creative_manifest.assets for build, flows through to the output manifest, and is available in the output for preview. No need to pass it separately at each step.

Examples

Example 1: Pure Generation (Generative Format)

Generate a creative from scratch using a generative format that requires promoted_offerings:

{
  "message": "Create a display banner for our winter sale. Use warm colors and emphasize the 50% discount",
  "target_format_id": {
    "agent_url": "https://creative.adcontextprotocol.org",
    "id": "display_300x250_generative"
  },
  "creative_manifest": {
    "format_id": {
      "agent_url": "https://creative.adcontextprotocol.org",
      "id": "display_300x250_generative"
    },
    "assets": {
      "promoted_offerings": {
        "brand_manifest": {
          "url": "https://mybrand.com",
          "name": "My Brand",
          "colors": {
            "primary": "#FF5733",
            "secondary": "#C70039"
          }
        },
        "inline_offerings": [
          {
            "name": "Winter Sale Collection",
            "description": "50% off all winter items"
          }
        ]
      }
    }
  }
}

Response:

{
  "creative_manifest": {
    "format_id": {
      "agent_url": "https://creative.adcontextprotocol.org",
      "id": "display_300x250"
    },
    "promoted_offering": "Winter Sale Collection",
    "assets": {
      "banner_image": {
        "asset_type": "image",
        "url": "https://cdn.creative-agent.com/generated/banner_12345.png",
        "width": 300,
        "height": 250
      },
      "clickthrough_url": {
        "asset_type": "url",
        "url": "https://mybrand.com/winter-sale"
      }
    }
  }
}

Example 2: Format Transformation

Transform an existing 728x90 leaderboard to a 300x250 banner:

{
  "message": "Adapt this leaderboard creative to a 300x250 banner format",
  "creative_manifest": {
    "format_id": {
      "agent_url": "https://creative.adcontextprotocol.org",
      "id": "display_728x90"
    },
    "promoted_offering": "Spring Collection",
    "assets": {
      "banner_image": {
        "asset_type": "image",
        "url": "https://cdn.mybrand.com/leaderboard.png",
        "width": 728,
        "height": 90
      },
      "headline": {
        "asset_type": "text",
        "content": "Spring Sale - 30% Off Everything"
      },
      "clickthrough_url": {
        "asset_type": "url",
        "url": "https://mybrand.com/spring"
      }
    }
  },
  "target_format_id": {
    "agent_url": "https://creative.adcontextprotocol.org",
    "id": "display_300x250"
  }
}

Response:

{
  "creative_manifest": {
    "format_id": {
      "agent_url": "https://creative.adcontextprotocol.org",
      "id": "display_300x250"
    },
    "promoted_offering": "Spring Collection",
    "assets": {
      "banner_image": {
        "asset_type": "image",
        "url": "https://cdn.creative-agent.com/resized/banner_67890.png",
        "width": 300,
        "height": 250
      },
      "headline": {
        "asset_type": "text",
        "content": "Spring Sale - 30% Off"
      },
      "clickthrough_url": {
        "asset_type": "url",
        "url": "https://mybrand.com/spring"
      }
    }
  }
}

Example 3: Transformation with Specific Instructions

Adapt a creative for mobile with specific design changes:

{
  "message": "Make this mobile-friendly: increase text size, simplify the layout, and make the CTA button more prominent",
  "creative_manifest": {
    "format_id": {
      "agent_url": "https://creative.adcontextprotocol.org",
      "id": "display_300x600"
    },
    "assets": {
      "background_image": {
        "asset_type": "image",
        "url": "https://cdn.mybrand.com/bg.jpg",
        "width": 300,
        "height": 600
      },
      "headline": {
        "asset_type": "text",
        "content": "Discover Our New Collection"
      },
      "body_text": {
        "asset_type": "text",
        "content": "Shop the latest styles with free shipping on orders over $50"
      },
      "cta_text": {
        "asset_type": "text",
        "content": "Shop Now"
      }
    }
  },
  "target_format_id": {
    "agent_url": "https://creative.adcontextprotocol.org",
    "id": "display_mobile_320x50"
  }
}

Response:

{
  "creative_manifest": {
    "format_id": {
      "agent_url": "https://creative.adcontextprotocol.org",
      "id": "display_mobile_320x50"
    },
    "assets": {
      "banner_image": {
        "asset_type": "image",
        "url": "https://cdn.creative-agent.com/mobile/banner_mobile_123.png",
        "width": 320,
        "height": 50
      },
      "headline": {
        "asset_type": "text",
        "content": "New Collection - Shop Now"
      },
      "clickthrough_url": {
        "asset_type": "url",
        "url": "https://mybrand.com/new"
      }
    }
  }
}

Key Concepts

Transformation Model

build_creative follows a manifest-in, manifest-out model:

Input: Creative manifest (can be minimal or complete, includes required assets)
Process: Transform/generate based on message and manifest assets
Output: Target creative manifest ready for preview or sync

Pure Generation vs Transformation

Pure Generation: Provide minimal creative_manifest with just the format_id and required input assets (like promoted_offerings for generative formats). The creative agent generates output assets from scratch using message as guidance.
Transformation: Provide complete creative_manifest with all existing assets. The creative agent adapts existing assets to the target format, optionally following guidance in message.

Integration with Other Tasks

build_creative → Generates manifest
preview_creative → Renders the manifest (see preview_creative)
sync_creatives → Traffics the finalized manifest

This separation allows you to:

Build once, preview multiple times with different contexts
Iterate on build without re-syncing
Preview before committing to traffic

Getting Started

Protocols

Signals

Curation Protocol

Media Buy

Creative

Reference

Community

Request Parameters

Use Cases

Pure Generation (Creating from Scratch)

Transformation (Adapting Existing Creative)

Format Resizing

Response Format

Field Descriptions

Workflow Integration

Typical Generation Workflow

Examples

Example 1: Pure Generation (Generative Format)

Example 2: Format Transformation

Example 3: Transformation with Specific Instructions

Key Concepts

Transformation Model

Pure Generation vs Transformation

Integration with Other Tasks

​Request Parameters

​Use Cases

​Pure Generation (Creating from Scratch)

​Transformation (Adapting Existing Creative)

​Format Resizing

​Response Format

​Field Descriptions

​Workflow Integration

​Typical Generation Workflow

​Examples

​Example 1: Pure Generation (Generative Format)

​Example 2: Format Transformation

​Example 3: Transformation with Specific Instructions

​Key Concepts

​Transformation Model

​Pure Generation vs Transformation

​Integration with Other Tasks

Request Parameters

Use Cases

Pure Generation (Creating from Scratch)

Transformation (Adapting Existing Creative)

Format Resizing

Response Format

Field Descriptions

Workflow Integration

Typical Generation Workflow

Examples

Example 1: Pure Generation (Generative Format)

Example 2: Format Transformation

Example 3: Transformation with Specific Instructions

Key Concepts

Transformation Model

Pure Generation vs Transformation

Integration with Other Tasks