Fetch Middleware for OAuth2

Common errors

Warnings

Install

Imports

• OAuth2
  wrong

  const { OAuth2 } = require('fetch-mw-oauth2')

  correct

  import { OAuth2 } from 'fetch-mw-oauth2'

  Since v3.0.0, this library is ESM-only. CommonJS `require()` is not supported.

• OAuth2 types

  import type { OAuth2Options, OAuth2Token } from 'fetch-mw-oauth2'

  TypeScript types are shipped with the package for improved development experience.

• OAuth2 instance creation and usage

  import { OAuth2 } from 'fetch-mw-oauth2';
  
  const oauth2 = new OAuth2({
    clientId: 'your-client-id',
    clientSecret: process.env.OAUTH_CLIENT_SECRET ?? '', // Optional in some cases
    tokenEndpoint: 'https://auth.example.org/token',
  }, {
    accessToken: 'initial-access-token',
    refreshToken: 'initial-refresh-token',
  });
  
  const response = await oauth2.fetch('https://api.example.org/data');

  The primary interaction is creating an OAuth2 instance and then using its `fetch` method, which transparently handles token management.

Quickstart

This example demonstrates how to set up `fetch-mw-oauth2` using the client_credentials grant to automatically handle OAuth2 authentication and fetch a protected resource. It utilizes environment variables for sensitive data.

import { OAuth2 } from 'fetch-mw-oauth2';

async function authenticateAndFetch() {
  // Configure OAuth2 for the client_credentials grant type
  const oauth2 = new OAuth2({
    grantType: 'client_credentials',
    clientId: 'your-client-id',
    clientSecret: process.env.OAUTH_CLIENT_SECRET ?? '', // Ensure this is loaded from environment variables
    tokenEndpoint: 'https://auth.example.com/token',
    scope: 'api:read api:write'
  });

  try {
    // Use the wrapped fetch function which automatically handles Authorization headers and token refreshes
    const response = await oauth2.fetch('https://api.example.com/protected-resource', {
      method: 'GET',
      headers: {
        'Accept': 'application/json'
      }
    });

    if (!response.ok) {
      throw new Error(`HTTP error! status: ${response.status}`);
    }

    const data = await response.json();
    console.log('Fetched data:', data);

  } catch (error) {
    console.error('Failed to fetch data with OAuth2:', error);
  }
}

authenticateAndFetch();