Request Interceptors in JavaScript
From the Axios cheat sheet · Interceptors & Error Handling · verified Jul 2026
Request Interceptors
Modify requests before they are sent
javascript
// Add request interceptor
axios.interceptors.request.use(
(config) => {
// Modify config before request is sent
const token = localStorage.getItem('token');
if (token) {
config.headers.Authorization = \`Bearer \${token}\`;
}
console.log('Request:', config.method, config.url);
return config;
},
(error) => {
// Handle request error
return Promise.reject(error);
}
);✅ Perfect for adding auth tokens to every request globally
💡 Multiple interceptors execute in the order they were added
🔍 Must return config object or Promise for request to proceed
⚡ Use eject() to remove interceptor if no longer needed
interceptorsrequestmiddlewareauth
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