API Design

# 资源使用名词、复数、小写、短横线连接
GET    /api/v1/users
GET    /api/v1/users/:id
POST   /api/v1/users
PUT    /api/v1/users/:id
PATCH  /api/v1/users/:id
DELETE /api/v1/users/:id

# 用于关系的子资源
GET    /api/v1/users/:id/orders
POST   /api/v1/users/:id/orders

# 非 CRUD 映射的操作（谨慎使用动词）
POST   /api/v1/orders/:id/cancel
POST   /api/v1/auth/login
POST   /api/v1/auth/refresh

# 良好
/api/v1/team-members          # 多单词资源使用 kebab-case
/api/v1/orders?status=active  # 查询参数用于过滤
/api/v1/users/123/orders      # 嵌套资源表示所有权关系

# 不良
/api/v1/getUsers              # URL 中包含动词
/api/v1/user                  # 使用单数形式（应使用复数）
/api/v1/team_members          # URL 中使用 snake_case
/api/v1/users/123/getOrders   # 嵌套资源路径中包含动词

# 成功
200 OK                    — GET、PUT、PATCH（包含响应体）
201 Created               — POST（包含 Location 头部）
204 No Content            — DELETE、PUT（无响应体）

# 客户端错误
400 Bad Request           — 验证失败、JSON 格式错误
401 Unauthorized          — 缺少或无效的身份验证
403 Forbidden             — 已认证但未授权
404 Not Found             — 资源不存在
409 Conflict              — 重复条目、状态冲突
422 Unprocessable Entity  — 语义无效（JSON 格式正确但数据错误）
429 Too Many Requests     — 超出速率限制

# 服务器错误
500 Internal Server Error — 意外故障（切勿暴露细节）
502 Bad Gateway           — 上游服务失败
503 Service Unavailable   — 临时过载，需包含 Retry-After 头部

# 错误：对所有请求都返回 200
{ "status": 200, "success": false, "error": "Not found" }

# 正确：按语义使用 HTTP 状态码
HTTP/1.1 404 Not Found
{ "error": { "code": "not_found", "message": "User not found" } }

# 错误：验证错误返回 500
# 正确：返回 400 或 422 并包含字段级详情

# 错误：创建资源返回 200
# 正确：返回 201 并包含 Location 标头
HTTP/1.1 201 Created
Location: /api/v1/users/abc-123

{
  "data": {
    "id": "abc-123",
    "email": "alice@example.com",
    "name": "Alice",
    "created_at": "2025-01-15T10:30:00Z"
  }
}

{
  "data": [
    { "id": "abc-123", "name": "Alice" },
    { "id": "def-456", "name": "Bob" }
  ],
  "meta": {
    "total": 142,
    "page": 1,
    "per_page": 20,
    "total_pages": 8
  },
  "links": {
    "self": "/api/v1/users?page=1&per_page=20",
    "next": "/api/v1/users?page=2&per_page=20",
    "last": "/api/v1/users?page=8&per_page=20"
  }
}

{
  "error": {
    "code": "validation_error",
    "message": "Request validation failed",
    "details": [
      {
        "field": "email",
        "message": "Must be a valid email address",
        "code": "invalid_format"
      },
      {
        "field": "age",
        "message": "Must be between 0 and 150",
        "code": "out_of_range"
      }
    ]
  }
}

// Option A: Envelope with data wrapper (recommended for public APIs)
interface ApiResponse<T> {
  data: T;
  meta?: PaginationMeta;
  links?: PaginationLinks;
}

interface ApiError {
  error: {
    code: string;
    message: string;
    details?: FieldError[];
  };
}

// Option B: Flat response (simpler, common for internal APIs)
// Success: just return the resource directly
// Error: return error object
// Distinguish by HTTP status code

GET /api/v1/users?page=2&per_page=20

# 实现
SELECT * FROM users
ORDER BY created_at DESC
LIMIT 20 OFFSET 20;

GET /api/v1/users?cursor=eyJpZCI6MTIzfQ&limit=20

# 实现
SELECT * FROM users
WHERE id > :cursor_id
ORDER BY id ASC
LIMIT 21;  -- 多取一条以判断是否有下一页

{
  "data": [...],
  "meta": {
    "has_next": true,
    "next_cursor": "eyJpZCI6MTQzfQ"
  }
}

# 简单相等
GET /api/v1/orders?status=active&customer_id=abc-123

# 比较运算符（使用括号表示法）
GET /api/v1/products?price[gte]=10&price[lte]=100
GET /api/v1/orders?created_at[after]=2025-01-01

# 多个值（逗号分隔）
GET /api/v1/products?category=electronics,clothing

# 嵌套字段（点表示法）
GET /api/v1/orders?customer.country=US

# 单字段排序（前缀 - 表示降序）
GET /api/v1/products?sort=-created_at

# 多字段排序（逗号分隔）
GET /api/v1/products?sort=-featured,price,-created_at

# 搜索查询参数
GET /api/v1/products?q=wireless+headphones

# 字段特定搜索
GET /api/v1/users?email=alice

# 仅返回指定字段（减少负载）
GET /api/v1/users?fields=id,name,email
GET /api/v1/orders?fields=id,total,status&include=customer.name

# Bearer token in Authorization header
GET /api/v1/users
Authorization: Bearer eyJhbGciOiJIUzI1NiIs...

# API key (for server-to-server)
GET /api/v1/data
X-API-Key: sk_live_abc123

// Resource-level: check ownership
app.get("/api/v1/orders/:id", async (req, res) => {
  const order = await Order.findById(req.params.id);
  if (!order) return res.status(404).json({ error: { code: "not_found" } });
  if (order.userId !== req.user.id) return res.status(403).json({ error: { code: "forbidden" } });
  return res.json({ data: order });
});

// Role-based: check permissions
app.delete("/api/v1/users/:id", requireRole("admin"), async (req, res) => {
  await User.delete(req.params.id);
  return res.status(204).send();
});

HTTP/1.1 200 OK
X-RateLimit-Limit: 100
X-RateLimit-Remaining: 95
X-RateLimit-Reset: 1640000000

# 超出限制时
HTTP/1.1 429 Too Many Requests
Retry-After: 60
{
  "error": {
    "code": "rate_limit_exceeded",
    "message": "Rate limit exceeded. Try again in 60 seconds."
  }
}

/api/v1/users
/api/v2/users

GET /api/users
Accept: application/vnd.myapp.v2+json

1. 从 /api/v1/ 开始 —— 除非必要，否则不要急于版本化
2. 最多同时维护 2 个活跃版本（当前版本 + 前一个版本）
3. 弃用时间线：
   - 宣布弃用（公共 API 需提前 6 个月通知）
   - 添加 Sunset 响应头：Sunset: Sat, 01 Jan 2026 00:00:00 GMT
   - 在弃用日期后返回 410 Gone 状态
4. 非破坏性变更无需创建新版本：
   - 向响应中添加新字段
   - 添加新的可选查询参数
   - 添加新的端点
5. 破坏性变更需要创建新版本：
   - 移除或重命名字段
   - 更改字段类型
   - 更改 URL 结构
   - 更改身份验证方法

import { z } from "zod";
import { NextRequest, NextResponse } from "next/server";

const createUserSchema = z.object({
  email: z.string().email(),
  name: z.string().min(1).max(100),
});

export async function POST(req: NextRequest) {
  const body = await req.json();
  const parsed = createUserSchema.safeParse(body);

  if (!parsed.success) {
    return NextResponse.json({
      error: {
        code: "validation_error",
        message: "Request validation failed",
        details: parsed.error.issues.map(i => ({
          field: i.path.join("."),
          message: i.message,
          code: i.code,
        })),
      },
    }, { status: 422 });
  }

  const user = await createUser(parsed.data);

  return NextResponse.json(
    { data: user },
    {
      status: 201,
      headers: { Location: `/api/v1/users/${user.id}` },
    },
  );
}

from rest_framework import serializers, viewsets, status
from rest_framework.response import Response

class CreateUserSerializer(serializers.Serializer):
    email = serializers.EmailField()
    name = serializers.CharField(max_length=100)

class UserSerializer(serializers.ModelSerializer):
    class Meta:
        model = User
        fields = ["id", "email", "name", "created_at"]

class UserViewSet(viewsets.ModelViewSet):
    serializer_class = UserSerializer
    permission_classes = [IsAuthenticated]

    def get_serializer_class(self):
        if self.action == "create":
            return CreateUserSerializer
        return UserSerializer

    def create(self, request):
        serializer = CreateUserSerializer(data=request.data)
        serializer.is_valid(raise_exception=True)
        user = UserService.create(**serializer.validated_data)
        return Response(
            {"data": UserSerializer(user).data},
            status=status.HTTP_201_CREATED,
            headers={"Location": f"/api/v1/users/{user.id}"},
        )

func (h *UserHandler) CreateUser(w http.ResponseWriter, r *http.Request) {
    var req CreateUserRequest
    if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
        writeError(w, http.StatusBadRequest, "invalid_json", "Invalid request body")
        return
    }

    if err := req.Validate(); err != nil {
        writeError(w, http.StatusUnprocessableEntity, "validation_error", err.Error())
        return
    }

    user, err := h.service.Create(r.Context(), req)
    if err != nil {
        switch {
        case errors.Is(err, domain.ErrEmailTaken):
            writeError(w, http.StatusConflict, "email_taken", "Email already registered")
        default:
            writeError(w, http.StatusInternalServerError, "internal_error", "Internal error")
        }
        return
    }

    w.Header().Set("Location", fmt.Sprintf("/api/v1/users/%s", user.ID))
    writeJSON(w, http.StatusCreated, map[string]any{"data": user})
}