How to build a public Microsoft To Do integration: Building the Auth Flow

Aug 1, 2024 • 6 minute read

Hey there, fellow JavaScript enthusiast! Ready to dive into the world of Microsoft To Do integration? Let's focus on the most crucial part: building a rock-solid auth flow. Buckle up, because we're about to make your integration secure and user-friendly.

Introduction

Microsoft To Do's API is a powerful tool, but without proper authentication, it's like having a sports car without the keys. We'll walk through setting up OAuth 2.0 authentication, ensuring your users can securely access their To Do lists.

Prerequisites

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

A Microsoft Azure account (if you don't have one, now's the time to sign up!)
An application registered in the Azure Portal (trust me, it's easier than it sounds)

OAuth 2.0 Flow Overview

We'll be using the Authorization Code Grant flow. It's like a secret handshake between your app and Microsoft's servers, keeping everything secure and above board.

Setting up the Authorization Request

First things first, let's construct that authorization URL:

const authUrl = 'https://login.microsoftonline.com/common/oauth2/v2.0/authorize';
const clientId = 'YOUR_CLIENT_ID';
const redirectUri = 'YOUR_REDIRECT_URI';
const scope = 'Tasks.ReadWrite';

const url = `${authUrl}?client_id=${clientId}&response_type=code&redirect_uri=${redirectUri}&scope=${scope}`;

Pro tip: For Microsoft To Do, you'll want to use the Tasks.ReadWrite scope.

Handling the Authorization Response

Once the user grants permission, you'll get a response with an authorization code. Grab it like this:

const urlParams = new URLSearchParams(window.location.search);
const code = urlParams.get('code');

Don't forget to handle errors! Check for an error parameter in the response.

Exchanging the Authorization Code for Access Token

Now for the good stuff. Let's trade that code for an access token:

const tokenUrl = 'https://login.microsoftonline.com/common/oauth2/v2.0/token';

const response = await fetch(tokenUrl, {
  method: 'POST',
  headers: {
    'Content-Type': 'application/x-www-form-urlencoded',
  },
  body: new URLSearchParams({
    client_id: clientId,
    scope: scope,
    code: code,
    redirect_uri: redirectUri,
    grant_type: 'authorization_code',
    client_secret: 'YOUR_CLIENT_SECRET', // Be careful with this!
  }),
});

const data = await response.json();
const accessToken = data.access_token;

Refreshing the Access Token

Access tokens don't last forever. When they expire, use the refresh token to get a new one:

const refreshToken = data.refresh_token;

// When it's time to refresh...
const refreshResponse = await fetch(tokenUrl, {
  method: 'POST',
  headers: {
    'Content-Type': 'application/x-www-form-urlencoded',
  },
  body: new URLSearchParams({
    client_id: clientId,
    scope: scope,
    refresh_token: refreshToken,
    grant_type: 'refresh_token',
    client_secret: 'YOUR_CLIENT_SECRET',
  }),
});

const refreshData = await refreshResponse.json();
const newAccessToken = refreshData.access_token;

Remember, store those refresh tokens securely!

Making Authenticated Requests

You've got the golden ticket (access token), now use it:

const todoListResponse = await fetch('https://graph.microsoft.com/v1.0/me/todo/lists', {
  headers: {
    'Authorization': `Bearer ${accessToken}`,
  },
});

const todoLists = await todoListResponse.json();

If you get a 401 error, it's probably time to refresh that token.

Security Considerations

Security is no joke. Consider implementing PKCE (Proof Key for Code Exchange) for added protection. And please, for the love of all that is holy, store your tokens securely. No plain text storage!

Conclusion

And there you have it! You've just built a secure auth flow for your Microsoft To Do integration. Pat yourself on the back – you've taken a big step towards creating an awesome, secure app.

Resources

Want to dive deeper? Check out:

Now go forth and build something amazing! Remember, with great power comes great responsibility. Use your new auth skills wisely!