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Designing APIs

Design robust and developer-friendly REST and GraphQL APIs with systematic guidance for API architecture, versioning strategies, authentication patterns, and best practices that ensure consistency, scalability, and excellent developer experience.

When to Use​

Use when:

  • Designing new REST or GraphQL APIs from scratch
  • Making architectural decisions between REST and GraphQL
  • Implementing API versioning strategies
  • Defining resource naming and URI structures
  • Establishing API authentication and authorization patterns
  • Creating API documentation with OpenAPI/Swagger

Key Features​

REST API Design​

  • Resource naming conventions and URI structure
  • HTTP method selection (GET, POST, PUT, PATCH, DELETE)
  • Status code usage and error response patterns
  • Pagination, filtering, and sorting strategies
  • HATEOAS and API discoverability

GraphQL API Design​

  • Schema design and type system
  • Query and mutation patterns
  • Resolver optimization and N+1 query prevention
  • Subscription design for real-time updates
  • Error handling and partial responses

API Versioning​

  • Versioning strategies (URL, header, content negotiation)
  • Deprecation policies and migration paths
  • Backward compatibility considerations
  • Semantic versioning for APIs

Authentication & Authorization​

  • OAuth 2.0 and OpenID Connect patterns
  • API key management
  • JWT token design and validation
  • Rate limiting and throttling

Quick Start​

REST API Example​

// Express.js REST API with proper conventions
const express = require('express');
const app = express();

// Resource-based routes
app.get('/api/v1/users', listUsers);           // List collection
app.post('/api/v1/users', createUser);         // Create resource
app.get('/api/v1/users/:id', getUser);         // Get single resource
app.put('/api/v1/users/:id', updateUser);      // Full update
app.patch('/api/v1/users/:id', partialUpdate); // Partial update
app.delete('/api/v1/users/:id', deleteUser);   // Delete resource

// Proper error response
function errorResponse(res, statusCode, message) {
  res.status(statusCode).json({
    error: {
      message,
      code: statusCode,
      timestamp: new Date().toISOString()
    }
  });
}

GraphQL API Example​

// Apollo Server GraphQL schema
const { ApolloServer, gql } = require('apollo-server');

const typeDefs = gql`
  type User {
    id: ID!
    email: String!
    name: String
    posts: [Post!]!
  }

  type Post {
    id: ID!
    title: String!
    content: String!
    author: User!
  }

  type Query {
    user(id: ID!): User
    users(limit: Int, offset: Int): [User!]!
  }

  type Mutation {
    createUser(email: String!, name: String): User!
    updateUser(id: ID!, name: String): User
  }
`;

const resolvers = {
  Query: {
    user: (_, { id }) => getUserById(id),
    users: (_, { limit = 10, offset = 0 }) => getUsers(limit, offset)
  },
  Mutation: {
    createUser: (_, { email, name }) => createUser(email, name)
  }
};

Primary Tools & Technologies​

  • REST Frameworks: Express.js, FastAPI, Django REST Framework, Spring Boot
  • GraphQL Tools: Apollo Server, GraphQL Yoga, Hasura
  • Documentation: Swagger/OpenAPI, GraphQL Playground, Postman
  • Validation: JSON Schema, Zod, Joi, GraphQL type system
  • Testing: Postman, Insomnia, REST Client, GraphQL testing libraries

References​