A package that makes using the OAuth2 PKCE flow easier

npm i js-pkce

Create a new instance of js-pkce with all of the details needed.

import PKCE from 'js-pkce';
const pkce = new PKCE({
  client_id: 'myclientid',
  redirect_uri: 'http://localhost:8080/auth',
  authorization_endpoint: 'https://authserver.com/oauth/authorize',
  token_endpoint: 'https://authserver.com/oauth/token',
  requested_scopes: '*',
});

Typically you just need to go to the authorization url to start the process. This example is something that might work in a SPA.

window.location.replace(pkce.authorizeUrl());

You may add additional query parameters to the authorize url by using an optional second parameter:

const additionalParams = {test_param: 'testing'};
window.location.replace(pkce.authorizeUrl(additionalParams));

After logging in with the authorization server, you will be redirected to the value in the redirect_uri parameter you set when creating the instance. Again, this is an example that might work for a SPA.

When you get back here, you need to exchange the code for a token.

const url = window.location.href;
pkce.exchangeForAccessToken(url).then((resp) => {
  const token = resp.access_token;
  // Do stuff with the access token.
});

As with the authorizeUrl method, an optional second parameter may be passed to the exchangeForAccessToken method to send additional parameters to the request:

const url = window.location.href;
const additionalParams = {test_param: 'testing'};

pkce.exchangeForAccessToken(url, additionalParams).then((resp) => {
  const token = resp.access_token;
  // Do stuff with the access token.
});

Get a new access token using a refresh token

pkce.refreshAccessToken(refreshToken).then((resp) => {
  const accessToken = resp.access_token;
  const refreshToken = resp.refresh_token;
  // Do stuff with the access & refresh token.
});

By default, this package will use sessionStorage to persist the pkce_state. On (mostly) mobile devices there's a higher chance users are returning in a different browser tab. E.g. they kick off in a WebView & get redirected to a new tab. The sessionStorage will be empty there.

In this case it you can opt in to use localStorage instead of sessionStorage:

import PKCE from 'js-pkce';
const pkce = new PKCE({
  // ...
  storage: localStorage, // any Storage object, sessionStorage (default) or localStorage 
});

When using httpOnly cookies, there is some additional configuration required. The method enableCorsCredentials can be called to allow sending credentials.

pkce.enableCorsCredentials(true);