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api-design-principles

api-design-principles

github.com/ovachiever开发5654 次安装49 周前更新
代码仓库

关于 api-design-principles

面向开发者的 REST 与 GraphQL API 设计和审查指南,涵盖版本管理、分页、错误处理及模式设计。

主要功能

  1. 01REST 资源与 HTTP 方法规范
  2. 02GraphQL 模式与解析器指南
  3. 03API 版本管理策略
  4. 04分页与错误处理
  5. 05模板和审查清单

适用场景

  1. 01规划新的 REST 或 GraphQL API
  2. 02实现前审查 API 规范
  3. 03为团队制定 API 标准
  4. 04重构端点以提升易用性

安装

复制下面的命令,在终端中运行。

$npx skills add https://github.com/ovachiever/droid-tings --skill api-design-principles

安装后在 Claude Code 中输入/api-design-principles确认已加载。

包含的文件

除 SKILL.md 外,安装时一起下载的参考资料和脚本。

assets/
api-design-checklist.md
rest-api-template.py
references/
graphql-schema-design.md
rest-best-practices.md

详细介绍

API 设计原则

掌握 REST 和 GraphQL API 设计原则,构建直观、可扩展、易维护的 API,让开发者满意,并经得起时间考验。

何时使用此技能

  • 设计新的 REST 或 GraphQL API
  • 重构现有 API,提升易用性
  • 为团队制定 API 设计标准
  • 在实现前审查 API 规范
  • 在不同 API 范式之间迁移(例如,从 REST 迁移到 GraphQL)
  • 编写方便开发者使用的 API 文档
  • 针对特定用例(移动端、第三方集成)优化 API

核心概念

1. RESTful 设计原则

以资源为导向的架构

  • 资源是名词(用户、订单、产品),而不是动词
  • 使用 HTTP 方法执行操作(GET、POST、PUT、PATCH、DELETE)
  • URL 表示资源层级
  • 使用一致的命名约定

HTTP 方法语义:

  • GET:检索资源(幂等且安全)
  • POST:创建新资源
  • PUT:替换整个资源(幂等)
  • PATCH:部分更新资源
  • DELETE:删除资源(幂等)
2. GraphQL 设计原则

以 Schema 为先的开发

  • 类型定义领域模型
  • 使用查询读取数据
  • 使用变更修改数据
  • 使用订阅实时更新

查询结构:

  • 客户端按需请求数据
  • 单一端点支持多个操作
  • 强类型 Schema
  • 内置自省功能
3. API 版本控制策略

URL 版本控制:

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

Header 版本控制:

Accept: application/vnd.api+json; version=1

查询参数版本控制:

/api/users?version=1

REST API 设计模式

模式 1:资源集合设计
# Good: Resource-oriented endpoints
GET    /api/users              # List users (with pagination)
POST   /api/users              # Create user
GET    /api/users/{id}         # Get specific user
PUT    /api/users/{id}         # Replace user
PATCH  /api/users/{id}         # Update user fields
DELETE /api/users/{id}         # Delete user

# Nested resources
GET    /api/users/{id}/orders  # Get user's orders
POST   /api/users/{id}/orders  # Create order for user

# Bad: Action-oriented endpoints (avoid)
POST   /api/createUser
POST   /api/getUserById
POST   /api/deleteUser
模式 2:分页和筛选
from typing import List, Optional
from pydantic import BaseModel, Field

class PaginationParams(BaseModel):
    page: int = Field(1, ge=1, description="Page number")
    page_size: int = Field(20, ge=1, le=100, description="Items per page")

class FilterParams(BaseModel):
    status: Optional[str] = None
    created_after: Optional[str] = None
    search: Optional[str] = None

class PaginatedResponse(BaseModel):
    items: List[dict]
    total: int
    page: int
    page_size: int
    pages: int

    @property
    def has_next(self) -> bool:
        return self.page < self.pages

    @property
    def has_prev(self) -> bool:
        return self.page > 1

# FastAPI endpoint example
from fastapi import FastAPI, Query, Depends

app = FastAPI()

@app.get("/api/users", response_model=PaginatedResponse)
async def list_users(
    page: int = Query(1, ge=1),
    page_size: int = Query(20, ge=1, le=100),
    status: Optional[str] = Query(None),
    search: Optional[str] = Query(None)
):
    # Apply filters
    query = build_query(status=status, search=search)

    # Count total
    total = await count_users(query)

    # Fetch page
    offset = (page - 1) * page_size
    users = await fetch_users(query, limit=page_size, offset=offset)

    return PaginatedResponse(
        items=users,
        total=total,
        page=page,
        page_size=page_size,
        pages=(total + page_size - 1) // page_size
    )
模式 3:错误处理和状态码
from fastapi import HTTPException, status
from pydantic import BaseModel

class ErrorResponse(BaseModel):
    error: str
    message: str
    details: Optional[dict] = None
    timestamp: str
    path: str

class ValidationErrorDetail(BaseModel):
    field: str
    message: str
    value: Any

# Consistent error responses
STATUS_CODES = {
    "success": 200,
    "created": 201,
    "no_content": 204,
    "bad_request": 400,
    "unauthorized": 401,
    "forbidden": 403,
    "not_found": 404,
    "conflict": 409,
    "unprocessable": 422,
    "internal_error": 500
}

def raise_not_found(resource: str, id: str):
    raise HTTPException(
        status_code=status.HTTP_404_NOT_FOUND,
        detail={
            "error": "NotFound",
            "message": f"{resource} not found",
            "details": {"id": id}
        }
    )

def raise_validation_error(errors: List[ValidationErrorDetail]):
    raise HTTPException(
        status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
        detail={
            "error": "ValidationError",
            "message": "Request validation failed",
            "details": {"errors": [e.dict() for e in errors]}
        }
    )

# Example usage
@app.get("/api/users/{user_id}")
async def get_user(user_id: str):
    user = await fetch_user(user_id)
    if not user:
        raise_not_found("User", user_id)
    return user
模式 4:HATEOAS(超媒体作为应用状态引擎)
class UserResponse(BaseModel):
    id: str
    name: str
    email: str
    _links: dict

    @classmethod
    def from_user(cls, user: User, base_url: str):
        return cls(
            id=user.id,
            name=user.name,
            email=user.email,
            _links={
                "self": {"href": f"{base_url}/api/users/{user.id}"},
                "orders": {"href": f"{base_url}/api/users/{user.id}/orders"},
                "update": {
                    "href": f"{base_url}/api/users/{user.id}",
                    "method": "PATCH"
                },
                "delete": {
                    "href": f"{base_url}/api/users/{user.id}",
                    "method": "DELETE"
                }
            }
        )

GraphQL 设计模式

模式 1:Schema 设计
# schema.graphql

# Clear type definitions
type User {
  id: ID!
  email: String!
  name: String!
  createdAt: DateTime!

  # Relationships
  orders(
    first: Int = 20
    after: String
    status: OrderStatus
  ): OrderConnection!

  profile: UserProfile
}

type Order {
  id: ID!
  status: OrderStatus!
  total: Money!
  items: [OrderItem!]!
  createdAt: DateTime!

  # Back-reference
  user: User!
}

# Pagination pattern (Relay-style)
type OrderConnection {
  edges: [OrderEdge!]!
  pageInfo: PageInfo!
  totalCount: Int!
}

type OrderEdge {
  node: Order!
  cursor: String!
}

type PageInfo {
  hasNextPage: Boolean!
  hasPreviousPage: Boolean!
  startCursor: String
  endCursor: String
}

# Enums for type safety
enum OrderStatus {
  PENDING
  CONFIRMED
  SHIPPED
  DELIVERED
  CANCELLED
}

# Custom scalars
scalar DateTime
scalar Money

# Query root
type Query {
  user(id: ID!): User
  users(
    first: Int = 20
    after: String
    search: String
  ): UserConnection!

  order(id: ID!): Order
}

# Mutation root
type Mutation {
  createUser(input: CreateUserInput!): CreateUserPayload!
  updateUser(input: UpdateUserInput!): UpdateUserPayload!
  deleteUser(id: ID!): DeleteUserPayload!

  createOrder(input: CreateOrderInput!): CreateOrderPayload!
}

# Input types for mutations
input CreateUserInput {
  email: String!
  name: String!
  password: String!
}

# Payload types for mutations
type CreateUserPayload {
  user: User
  errors: [Error!]
}

type Error {
  field: String
  message: String!
}
模式 2:解析器设计
from typing import Optional, List
from ariadne import QueryType, MutationType, ObjectType
from dataclasses import dataclass

query = QueryType()
mutation = MutationType()
user_type = ObjectType("User")

@query.field("user")
async def resolve_user(obj, info, id: str) -> Optional[dict]:
    """Resolve single user by ID."""
    return await fetch_user_by_id(id)

@query.field("users")
async def resolve_users(
    obj,
    info,
    first: int = 20,
    after: Optional[str] = None,
    search: Optional[str] = None
) -> dict:
    """Resolve paginated user list."""
    # Decode cursor
    offset = decode_cursor(after) if after else 0

    # Fetch users
    users = await fetch_users(
        limit=first + 1,  # Fetch one extra to check hasNextPage
        offset=offset,
        search=search
    )

    # Pagination
    has_next = len(users) > first
    if has_next:
        users = users[:first]

    edges = [
        {
            "node": user,
            "cursor": encode_cursor(offset + i)
        }
        for i, user in enumerate(users)
    ]

    return {
        "edges": edges,
        "pageInfo": {
            "hasNextPage": has_next,
            "hasPreviousPage": offset > 0,
            "startCursor": edges[0]["cursor"] if edges else None,
            "endCursor": edges[-1]["cursor"] if edges else None
        },
        "totalCount": await count_users(search=search)
    }

@user_type.field("orders")
async def resolve_user_orders(user: dict, info, first: int = 20) -> dict:
    """Resolve user's orders (N+1 prevention with DataLoader)."""
    # Use DataLoader to batch requests
    loader = info.context["loaders"]["orders_by_user"]
    orders = await loader.load(user["id"])

    return paginate_orders(orders, first)

@mutation.field("createUser")
async def resolve_create_user(obj, info, input: dict) -> dict:
    """Create new user."""
    try:
        # Validate input
        validate_user_input(input)

        # Create user
        user = await create_user(
            email=input["email"],
            name=input["name"],
            password=hash_password(input["password"])
        )

        return {
            "user": user,
            "errors": []
        }
    except ValidationError as e:
        return {
            "user": None,
            "errors": [{"field": e.field, "message": e.message}]
        }
模式 3:DataLoader(避免 N+1 问题)
from aiodataloader import DataLoader
from typing import List, Optional

class UserLoader(DataLoader):
    """Batch load users by ID."""

    async def batch_load_fn(self, user_ids: List[str]) -> List[Optional[dict]]:
        """Load multiple users in single query."""
        users = await fetch_users_by_ids(user_ids)

        # Map results back to input order
        user_map = {user["id"]: user for user in users}
        return [user_map.get(user_id) for user_id in user_ids]

class OrdersByUserLoader(DataLoader):
    """Batch load orders by user ID."""

    async def batch_load_fn(self, user_ids: List[str]) -> List[List[dict]]:
        """Load orders for multiple users in single query."""
        orders = await fetch_orders_by_user_ids(user_ids)

        # Group orders by user_id
        orders_by_user = {}
        for order in orders:
            user_id = order["user_id"]
            if user_id not in orders_by_user:
                orders_by_user[user_id] = []
            orders_by_user[user_id].append(order)

        # Return in input order
        return [orders_by_user.get(user_id, []) for user_id in user_ids]

# Context setup
def create_context():
    return {
        "loaders": {
            "user": UserLoader(),
            "orders_by_user": OrdersByUserLoader()
        }
    }

最佳实践

REST API
  1. 命名一致:集合使用复数名词(/users,而不是 /user)
  2. 无状态:每个请求都包含所有必要信息
  3. 正确使用 HTTP 状态码:2xx 表示成功,4xx 表示客户端错误,5xx 表示服务端错误
  4. 为 API 进行版本控制:从一开始就为不兼容变更做好规划
  5. 分页:始终对大型集合进行分页
  6. 速率限制:通过速率限制保护 API
  7. 文档:使用 OpenAPI/Swagger 提供交互式文档
GraphQL API
  1. Schema 优先:先设计 Schema,再编写解析器
  2. 避免 N+1 问题:使用 DataLoader 高效获取数据
  3. 输入验证:在 Schema 和解析器层进行验证
  4. 错误处理:在变更负载中返回结构化错误
  5. 分页:使用基于游标的分页(Relay 规范)
  6. 弃用:使用 @deprecated 指令逐步迁移
  7. 监控:跟踪查询复杂度和执行时间

常见陷阱

  • 过度获取/获取不足(REST):GraphQL 可以解决此问题,但需要使用 DataLoader
  • 不兼容变更:为 API 进行版本控制,或采用弃用策略
  • 错误格式不一致:统一错误响应格式
  • 缺少速率限制:不设限制的 API 容易遭到滥用
  • 文档不完善:缺少文档的 API 会让开发者感到困扰
  • 忽视 HTTP 语义:对幂等操作使用 POST 会违背预期
  • 紧密耦合:API 结构不应照搬数据库 Schema

资源

  • references/rest-best-practices.md:REST API 设计综合指南
  • references/graphql-schema-design.md:GraphQL 模式的常见模式和反模式
  • references/api-versioning-strategies.md:版本管理方法和迁移路径
  • assets/rest-api-template.py:FastAPI REST API 模板
  • assets/graphql-schema-template.graphql:完整的 GraphQL 模式示例
  • assets/api-design-checklist.md:实施前审核清单
  • scripts/openapi-generator.py:从代码生成 OpenAPI 规范

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