Description

The official sync-creatives request example at https://adcontextprotocol.org/schemas/2.5.0/media-buy/sync-creatives-request.json includes video assets like:

{
  "assets": {
    "video": {
      "url": "https://cdn.example.com/hero-video.mp4",
      "width": 1920,
      "height": 1080,
      "duration_ms": 30000
    }
  }
}

However, when validating this against the schema using Ajv (a popular JSON Schema validator), validation fails because:

1. video-asset.json uses allOf combining dimensions.json with video-specific properties
2. Both dimensions.json and the video properties object have additionalProperties: false
3. In JSON Schema, allOf validates each sub-schema independently. The dimensions schema sees url/duration_ms as "additional" properties, and the video schema sees width/height as "additional" properties

This is a known JSON Schema limitation when combining allOf with additionalProperties: false.

Affected files

• /static/schemas/source/core/assets/video-asset.json (lines 6-36)
• /static/schemas/source/core/dimensions.json (line 20)
• Same issue affects image-asset.json

Proposed fix

Option 1: Remove additionalProperties: false from dimensions.json (since it's always used via allOf)

Option 2: Restructure the schemas to avoid the allOf + additionalProperties conflict, perhaps using $ref with property merging differently

Environment

• AdCP Schema version: v2.5.0
• JSON Schema validator: Ajv 8.x
• JSON Schema draft: draft-07