How to build a public ADP Workforce Now integration: Building the Auth Flow

Aug 3, 2024 • 8 minute read

Hey there, fellow JavaScript enthusiast! Ready to dive into the world of ADP Workforce Now integrations? Today, we're going to tackle one of the most crucial aspects of building a public integration: the authorization flow. Buckle up, because we're about to make your integration secure and user-friendly!

Introduction

ADP Workforce Now is a powerhouse when it comes to HR management, and its API opens up a world of possibilities for developers like us. But before we can tap into all that juicy data, we need to make sure we're doing it the right way. That's where authorization comes in. It's not just a box to tick – it's the foundation of a trustworthy integration.

Prerequisites

Before we jump in, make sure you've got:

An ADP developer account (if you don't have one, go grab it!)
A registered application in the ADP developer portal
Node.js installed on your machine
Your favorite package manager (npm or yarn) ready to go

We'll be using Express.js for our server and axios for making HTTP requests, so make sure you've got those installed too.

Understanding OAuth 2.0 Authorization Code Flow

Alright, let's talk OAuth 2.0 Authorization Code Flow. It sounds fancy, but it's actually pretty straightforward. This flow is perfect for user-facing integrations because it allows users to grant access to their data without sharing their credentials with us. It's like having a VIP pass that lets you into the party without knowing the secret handshake.

Setting up the server

Let's start by setting up a basic Express server:

const express = require('express');
const app = express();
const port = 3000;

app.get('/', (req, res) => res.send('Hello ADP!'));

app.listen(port, () => console.log(`Server running on port ${port}`));

Don't forget to set up your environment variables for your client ID and secret. Keep those safe!

Implementing the authorization flow

Step 1: Redirect user to ADP authorization URL

First, we need to send our users to ADP's authorization page. Here's how we construct that URL:

const authorizationUrl = `https://accounts.adp.com/auth/oauth/v2/authorize?client_id=${clientId}&response_type=code&redirect_uri=${redirectUri}&scope=api`;

app.get('/login', (req, res) => {
  res.redirect(authorizationUrl);
});

Step 2: Handle the callback

After the user grants permission, ADP will redirect them back to us with an authorization code. Let's catch that:

app.get('/callback', async (req, res) => {
  const { code } = req.query;
  // We'll use this code in the next step
});

Step 3: Exchange code for access token

Now for the exciting part – turning that code into an access token:

const axios = require('axios');

// In your callback route
const tokenResponse = await axios.post('https://accounts.adp.com/auth/oauth/v2/token', null, {
  params: {
    grant_type: 'authorization_code',
    code,
    client_id: process.env.ADP_CLIENT_ID,
    client_secret: process.env.ADP_CLIENT_SECRET,
    redirect_uri: redirectUri
  }
});

const { access_token, refresh_token } = tokenResponse.data;
// Store these tokens securely!

Refreshing the access token

Access tokens don't last forever, so we need to be ready to refresh them:

async function refreshAccessToken(refreshToken) {
  const response = await axios.post('https://accounts.adp.com/auth/oauth/v2/token', null, {
    params: {
      grant_type: 'refresh_token',
      refresh_token: refreshToken,
      client_id: process.env.ADP_CLIENT_ID,
      client_secret: process.env.ADP_CLIENT_SECRET
    }
  });

  return response.data.access_token;
}

Making authenticated requests

Now that we have our access token, let's use it to make some API calls:

async function getEmployeeData(accessToken) {
  const response = await axios.get('https://api.adp.com/hr/v2/workers', {
    headers: {
      Authorization: `Bearer ${accessToken}`
    }
  });

  return response.data;
}

Error handling and edge cases

Always be prepared for things to go wrong. Here's a quick example of how to handle errors:

app.use((err, req, res, next) => {
  console.error(err.stack);
  res.status(500).send('Something broke! But don\'t worry, we\'re on it.');
});

Security considerations

Remember, with great power comes great responsibility. Always use HTTPS in production, store tokens securely (consider using encryption at rest), and implement CSRF protection. Your users are trusting you with their data, so let's keep it safe!

Conclusion

And there you have it! You've just built the authorization flow for your ADP Workforce Now integration. Pretty cool, right? From here, you can start building out the rest of your integration, knowing that you've got a solid, secure foundation.

Additional resources

Want to dive deeper? Check out:

Remember, the key to a great integration is continuous learning and improvement. Keep exploring, keep coding, and most importantly, have fun with it! You've got this! 🚀