API_SPEC_cn.md

公开接口契约规范（API Specification）

• 接口路径：POST /v1/transactions
• 鉴权方式：Bearer <api_key>
• 幂等机制：通过 Idempotency-Key 请求头支持

请求结构契约（Request Body）

{
  "user_id": 101,
  "amount": 99.95,
  "currency": "USD",
  "status": "pending"
}

成功响应契约（200 OK）

{
  "transaction_id": "txn_8f7b2c",
  "user_id": 101,
  "amount": 99.95,
  "currency": "USD",
  "status": "pending",
  "created_at": "2026-09-02T12:00:00Z"
}

统一错误响应结构（4xx / 5xx）

{
  "error": {
    "code": "INVALID_PARAM",
    "message": "amount must be greater than 0",
    "field": "amount"
  }
}