Obtaining OAuth2 Client Credentials Token for Server-to-Server API Access

const fetch = require('node-fetch'); // In Node.js, install node-fetch for fetch API

const OAUTH_TOKEN_URL = 'https://your-oauth-server.com/token';
const CLIENT_ID = 'your-client-id';
const CLIENT_SECRET = 'your-client-secret';
const SCOPE = 'api.read api.write'; // Optional: scope for the token

async function getClientCredentialsToken() {
  try {
    const authString = Buffer.from(`${CLIENT_ID}:${CLIENT_SECRET}`).toString('base64');

    const response = await fetch(OAUTH_TOKEN_URL, {
      method: 'POST',
      headers: {
        'Content-Type': 'application/x-www-form-urlencoded',
        'Authorization': `Basic ${authString}`
      },
      body: new URLSearchParams({
        'grant_type': 'client_credentials',
        'scope': SCOPE
      }).toString()
    });

    if (!response.ok) {
      const errorData = await response.json();
      throw new Error(`Failed to get OAuth token: ${response.status} ${response.statusText} - ${JSON.stringify(errorData)}`);
    }

    const data = await response.json();
    console.log('Access Token:', data.access_token);
    console.log('Expires In:', data.expires_in);
    return data.access_token;
  } catch (error) {
    console.error('Error fetching OAuth token:', error);
    throw error;
  }
}

// Example usage:
// getClientCredentialsToken().then(token => {
//   console.log('Token successfully retrieved:', token);
// }).catch(err => {
//   console.error('Failed to get token in main call:', err);
// });