# 訂閱系統 API

## 概述
訂閱系統API負責管理用戶訂閱服務，包括方案管理、支付處理、權限控制和訪客訂閱功能。

## API 端點

### 獲取訂閱方案
```http
GET /api/v1/subscriptions/plans
Authorization: Bearer <access_token>

Response 200 OK
{
  "success": true,
  "data": {
    "plans": [
      {
        "plan_id": "PLAN_MONTHLY",
        "name": "月費會員",
        "description": "解鎖對話訓練功能，享受完整學習體驗",
        "price": {
          "monthly": {
            "amount": 600,
            "currency": "TWD",
            "test_discount": {
              "percentage": 80,
              "discounted_price": 120,
              "description": "內部測試期間2折優惠"
            }
          }
        },
        "features": [
          "解鎖所有對話訓練關卡",
          "無限制對話練習次數",
          "完整語言程度評估",
          "詳細學習分析報告"
        ]
      }
    ]
  }
}
```

## 錯誤處理
- `SUBSCRIPTION_REQUIRED`: 需要訂閱才能存取
- `SUBSCRIPTION_EXPIRED`: 訂閱已過期
- `PAYMENT_FAILED`: 付款處理失敗

---
**建立日期**: 2025-09-08  
**API版本**: v1