How to send a token in the header

Question

In my API-based application, I need to send a token in the HTTP header for authentication purposes. What is the proper way to include this token in the header using various methods (e.g., JavaScript fetch, Axios, or curl)? Are there best practices for securely handling and sending tokens?

Examples of implementing token-based authentication in both frontend and backend environments would be helpful.

Answer 1

In API-based applications, sending a token in the HTTP header is standard procedure for authorization and authentication. Here are examples using different methods to include this token in requests for API-based applications.

1. JavaScript Fetch API

fetch('https://api.example.com/data', {
    method: 'GET',
    headers: {
        'Authorization': 'Bearer your_token_here',
        'Content-Type': 'application/json'
    }
})
.then(response => response.json())
.then(data => console.log(data))
.catch(error => console.error('Error:', error));

2. Axios

import axios from 'axios';

axios.get('https://api.example.com/data', {
    headers: {
        'Authorization': `Bearer your_token_here`
    }
})
.then(response => console.log(response.data))
.catch(error => console.error('Error:', error));

3. cURL

curl -H "Authorization: Bearer your_token_here" -H "Content-Type: application/json" https://api.example.com/data

4. Node.js

To verify tokens on the server side in an Express app:

app.get('/data', (req, res) => {
    const token = req.headers['authorization']?.split(' ')[1];
    if (token) {
        // Verify the token here
        res.send('Token received and verified.');
    } else {
        res.status(403).send('No token provided.');
    }
});