Social and Native Ads

{
  "publisher_domain": "social.streamhaus.example",
  "format_option_id": "promoted_post",
  "format_kind": "native_in_feed",
  "params": {
    "title_max_chars": 100,
    "body_text_max_chars": 500,
    "slots": [
      { "asset_group_id": "title", "asset_type": "text", "required": true },
      { "asset_group_id": "body_text", "asset_type": "text", "required": false },
      { "asset_group_id": "main_image", "asset_type": "image", "required": true },
      { "asset_group_id": "advertiser_name", "asset_type": "text", "required": true },
      { "asset_group_id": "landing_page_url", "asset_type": "url", "required": true }
    ]
  }
}