基本コンセプト

ファネル
└── ステップ（公開URLを持つ）
    └── ページ（A/Bテスト時に複数可）
        └── 要素（section > row > col > コンテンツ要素）

curl -X POST "https://api.utage-system.com/v1/funnels" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"name": "プロモーションファネル"}'

curl -X POST "https://api.utage-system.com/v1/funnels/{funnel_id}/steps" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"name": "LP"}'

section       ← 最上位のコンテナ
└── row       ← 行
    └── col   ← 列
        └── コンテンツ要素（text, image, button, video, form 等）

[
    {
        "type": "section",
        "children": [
            {
                "type": "row",
                "children": [
                    {
                        "type": "col",
                        "children": [
                            {
                                "type": "text",
                                "content": "<p>こんにちは</p>"
                            }
                        ]
                    }
                ]
            }
        ]
    }
]

curl -X POST "https://api.utage-system.com/v1/accounts" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"name": "メイン配信", "type": "mail"}'

curl -X POST "https://api.utage-system.com/v1/accounts/{account_id}/scenarios" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"title": "メルマガ登録"}'