🔄 Interceptors

better-axios supports custom request and response interceptors, similar to native Axios. You can use them to modify headers, handle tokens, log responses, or implement features like token refresh.

🚀 Add Custom Interceptors

You can pass custom interceptors during initialization using requestInterceptor and responseInterceptor.

const api = new AxiosApi({
  baseURL: "https://api.example.com",
  requestInterceptor: async (config) => {
    // Add a custom header
    config.headers["X-App-Version"] = "1.0.0";
    return config;
  },
  responseInterceptor: async (response) => {
    // Log response or modify it
    console.log("Response received:", response.status);
    return response;
  },
});

🔁 Use Case: Refresh Expired Token

Here's a simplified example of intercepting a 401 error and retrying the request after refreshing the token.

const api = new AxiosApi({
  baseURL: "https://api.example.com",
  responseInterceptor: async (response) => {
    return response;
  },
});

// Add interceptor manually to retry requests after token refresh
api.getAxiosInstance().interceptors.response.use(
  (res) => res,
  async (error) => {
    const originalRequest = error.config;

    // Check for 401 and avoid infinite loop
    if (error.response?.status === 401 && !originalRequest._retry) {
      originalRequest._retry = true;

      // Assume we get a new token from refresh endpoint
      const res = await api.post<{ token: string }>("/auth/refresh");

      if (res.success) {
        api.setAuthToken(res.data.token);

        // Retry original request
        originalRequest.headers["Authorization"] = `Bearer ${res.data.token}`;
        return api.getAxiosInstance().request(originalRequest);
      }
    }

    return Promise.reject(error);
  }
);

✅ Why Use Interceptors?

🔐 Add or modify headers dynamically
🔄 Handle token refresh or session expiration
🐞 Centralized logging/debugging
🧹 Cleanly separate logic without modifying each request

🧠 Best Practices

Keep interceptors pure and async-safe
Always handle failures gracefully (especially inside responseInterceptor)
Avoid infinite retry loops—track retries via flags like _retry

Interceptors

🔄 Interceptors

🚀 Add Custom Interceptors

🔁 Use Case: Refresh Expired Token

✅ Why Use Interceptors?

🧠 Best Practices

On this page