Refreshing Your NextAuth Tokens with Axios Interceptors
NextAuth.js is a popular solution for authentication in Next.js applications, offering a seamless way to handle user logins and sessions. However, managing token expiration and refreshing them can be tricky. This is where Axios interceptors come in handy, providing a centralized and efficient way to handle token refreshes.
The Problem: Expired Tokens and API Requests
Imagine this scenario: a user logs into your Next.js application, successfully receives an access token, and starts making API calls. But, what happens when that access token expires? Without proper handling, your API requests will fail, leading to a frustrating user experience.
The Solution: Axios Interceptors and Token Refresh
Axios interceptors offer a convenient way to intercept requests and responses, allowing you to modify them before they are sent or received. This functionality can be leveraged for token refresh, as follows:
import axios from 'axios';
import { getServerSession } from 'next-auth/next';
// Function to refresh the access token
const refreshAccessToken = async () => {
try {
const session = await getServerSession();
if (!session) {
return null;
}
const response = await fetch('/api/auth/refresh', {
method: 'POST',
headers: {
'Content-Type': 'application/json',
Authorization: `Bearer ${session.user.accessToken}`,
},
});
const data = await response.json();
return data.accessToken;
} catch (error) {
console.error('Error refreshing token:', error);
return null;
}
};
// Axios Interceptor for token refresh
axios.interceptors.request.use(async (config) => {
const accessToken = config.headers.Authorization;
// Check if token exists and is not expired
if (accessToken && !isTokenExpired(accessToken)) {
return config;
}
const newToken = await refreshAccessToken();
if (newToken) {
config.headers.Authorization = `Bearer ${newToken}`;
return config;
}
return config;
}, (error) => {
// Handle request error
return Promise.reject(error);
});
// Helper function to check token expiration
const isTokenExpired = (token) => {
// Implement logic to check if token has expired
// This might involve parsing JWT payload or using a custom expiration check
// Example using a JWT expiry claim:
const decodedToken = jwtDecode(token.split(' ')[1]);
return decodedToken.exp < Date.now() / 1000;
};
Explanation:
refreshAccessToken: This function retrieves the user session, makes a request to your backend's refresh endpoint (e.g.,/api/auth/refresh), and returns the new access token.- Axios Interceptor: The interceptor checks for an existing access token and its expiration status. If the token is expired, it calls
refreshAccessTokento obtain a new one. - Token Update: The new access token is then added to the request headers.
isTokenExpired: This helper function checks if the token is expired, which can be implemented using a custom logic or by decoding the JWT payload to access its expiration timestamp.
Benefits of Axios Interceptors for Token Refresh
- Centralized Handling: All token refresh logic is contained within the interceptor, making your code more organized and easier to maintain.
- Automatic Refresh: The interceptor automatically refreshes the token when necessary, eliminating the need for manual token management in every API call.
- Improved User Experience: By seamlessly refreshing tokens, your application can avoid failed requests and maintain a smooth user experience.
Additional Considerations
- Error Handling: Handle errors that might occur during the refresh process, such as network failures or invalid refresh tokens.
- Token Storage: Ensure that the token refresh logic correctly handles token storage and updates, as this might involve updating the user session in NextAuth.js.
Conclusion
By using Axios interceptors, you can streamline your token refresh process in NextAuth.js, making your application more robust and user-friendly. This approach centralizes the token management logic, enhances security, and ensures a smoother user experience. Remember to adapt this implementation to your specific needs, including proper error handling and token storage mechanisms.
