How to build a public Uscreen integration: Building the Auth Flow

Aug 17, 2024 • 7 minute read

Hey there, fellow JavaScript devs! Ready to dive into the world of Uscreen integrations? Today, we're focusing on the crucial part of any integration: the authorization flow. Let's get your users connected to Uscreen securely and efficiently.

Introduction

Uscreen is a powerful video monetization platform, and integrating it into your app can open up a world of possibilities. But before we can do any of the fun stuff, we need to nail the auth flow. It's the gatekeeper of your integration, so let's make it rock-solid.

Prerequisites

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

Node.js installed (you knew that, right?)
Your favorite code editor
Uscreen API credentials (if you don't have these, hop over to Uscreen and get 'em)

Setting up the project

Let's get the boring stuff out of the way:

mkdir uscreen-integration
cd uscreen-integration
npm init -y
npm install express axios dotenv

Create a .env file for your secrets:

USCREEN_CLIENT_ID=your_client_id
USCREEN_CLIENT_SECRET=your_client_secret
REDIRECT_URI=http://localhost:3000/callback

Understanding OAuth 2.0 flow for Uscreen

Uscreen uses OAuth 2.0 with the authorization code grant. If you've worked with OAuth before, this'll be familiar. If not, don't sweat it – we'll break it down.

Implementing the authorization flow

Initiating the auth request

First, let's create a route to kick off the auth process:

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

app.get('/auth', (req, res) => {
  const authUrl = `https://www.uscreen.io/oauth/authorize?client_id=${process.env.USCREEN_CLIENT_ID}&redirect_uri=${encodeURIComponent(process.env.REDIRECT_URI)}&response_type=code`;
  res.redirect(authUrl);
});

This sends your user to Uscreen's auth page. They'll log in and grant permissions there.

Handling the callback

Now, let's set up the callback endpoint:

app.get('/callback', async (req, res) => {
  const { code } = req.query;
  if (!code) {
    return res.status(400).send('Authorization code missing');
  }
  
  // We'll exchange this code for an access token next
});

Exchanging the code for access token

Time to get that sweet, sweet access token:

const axios = require('axios');

// Inside your callback route
try {
  const response = await axios.post('https://www.uscreen.io/oauth/token', {
    client_id: process.env.USCREEN_CLIENT_ID,
    client_secret: process.env.USCREEN_CLIENT_SECRET,
    code,
    grant_type: 'authorization_code',
    redirect_uri: process.env.REDIRECT_URI
  });

  const { access_token, refresh_token } = response.data;
  // Store these tokens securely
  
  res.send('Authorization successful!');
} catch (error) {
  console.error('Error exchanging code for token:', error);
  res.status(500).send('Authorization failed');
}

Refreshing the access token

Access tokens don't last forever. Let's add a refresh function:

async function refreshAccessToken(refresh_token) {
  try {
    const response = await axios.post('https://www.uscreen.io/oauth/token', {
      client_id: process.env.USCREEN_CLIENT_ID,
      client_secret: process.env.USCREEN_CLIENT_SECRET,
      refresh_token,
      grant_type: 'refresh_token'
    });

    return response.data.access_token;
  } catch (error) {
    console.error('Error refreshing token:', error);
    throw error;
  }
}

Error handling and edge cases

Always expect the unexpected. Add try/catch blocks liberally and provide clear error messages to your users. Remember, they're not as tech-savvy as you!

Security considerations

Security isn't optional, folks. Here are some quick tips:

Always use HTTPS in production
Store tokens securely (not in plain text!)
Implement CSRF protection for your callback endpoint

Testing the auth flow

Manual testing is crucial. Go through the flow yourself, try to break it. For automated testing, consider mocking the Uscreen API responses to test your error handling.

Conclusion

And there you have it! You've just built a solid auth flow for your Uscreen integration. From here, you can start making API calls to Uscreen and building out the rest of your integration.

Remember, the auth flow is the foundation of your integration. Take the time to get it right, and the rest will follow smoothly.

Additional resources

Now go forth and integrate! If you hit any snags, don't hesitate to dive back into the docs or reach out to the community. Happy coding!