Get creative manifest

curl -X GET "https://api.interchange.io/api/v2/buyer/campaigns/cmp_987654321/creatives/cm_abcdef" \
  -H "Authorization: Bearer $SCOPE3_API_KEY"

{
  "creative_id": "cm_abcdef",
  "campaign_id": "cmp_987654321",
  "name": "Q2 hero video",
  "message": "30s product reveal — premium tone, 2-second hook",
  "template_id": "video_standard",
  "brand_domain": "acme.com",
  "format_id": { "id": "video_standard", "agent_url": "https://agent.example.com" },
  "preview_url": "https://storage.googleapis.com/creatives/cm_abcdef/preview.html",
  "assets": [
    {
      "asset_id": "asset_001",
      "name": "main_video",
      "original_filename": "hero-30s.mp4",
      "asset_type": "VIDEO",
      "content_type": "video/mp4",
      "file_size": 8421376,
      "public_url": "https://cdn.example.com/creatives/cm_abcdef/hero-30s.mp4",
      "asset_source": "USER_UPLOADED",
      "created_at": "2026-06-07T15:04:00Z"
    }
  ],
  "tracking": {
    "impression_tracker_url": "https://track.scope3.com/imp?cid={CAMPAIGN_ID}",
    "click_tracker_url": "https://track.scope3.com/clk?rurl=https%3A%2F%2Facme.com%2Fpromo",
    "supported_macros": ["CAMPAIGN_ID", "DEVICE_TYPE", "COUNTRY"]
  },
  "sync_status": { "synced": true, "agent_count": 3, "last_synced_at": "2026-06-07T16:20:00Z" },
  "created_at": "2026-06-07T15:04:00Z",
  "updated_at": "2026-06-07T15:04:00Z"
}