📘

Type-Safe API Client 🌐

Advanced

160 XP

65 min

Lesson Content

Type-Safe API Client 🌐

Build a fully typed API client that catches errors at compile time. This is production-level code!

API Client Types

interface ApiResponse {
  data: T;
  status: number;
  message: string;
}

interface User {
  id: number;
  name: string;
  email: string;
}

async function fetchUser(id: number): Promise> {
  const response = await fetch(`/api/users/${id}`);
  return response.json();
}

Example Code

Create typed API client

interface ApiResponse<T> {
  data: T;
  status: number;
  message: string;
}

interface User {
  id: number;
  name: string;
  email: string;
}

// Simulate API call
async function fetchUser(id: number): Promise<ApiResponse<User>> {
  return new Promise(resolve => {
    setTimeout(() => {
      resolve({
        data: { id, name: 'John', email: 'john@example.com' },
        status: 200,
        message: 'Success'
      });
    }, 100);
  });
}

fetchUser(1).then(result => {
  console.log('User:', result.data);
});

Expected Output:

Typed API response

Study Tips

•Read the theory content thoroughly before practicing
•Review the example code to understand key concepts
•Proceed to the Practice tab when you're ready to code