Outlook add-ins (and Office add-ins in general) are integrations built by third parties into Outlook by using Microsoft’s web-based platform. They are essentially web apps that run in the context of a browser in a sandbox with special access to Outlook items like email messages, meeting requests, responses and cancellations, and appointments.

Most Outlook add-ins are built to provide convenient integrations to a third party system or service right from Outlook, like Customer Relationship Management, Customer Service, Project Management, …

Many, if not all add-in developers end up developing the same or similar elements of their app:

  • Provision a backend API that will support the client code.
  • Implement user management (login/logout/session) which needs to be correlated with an authenticated Outlook user.
  • Support one or more 3rd party authorization flows. For example, a user needs to link his or her CRM account, maybe also a cloud file storage.
  • Proxy requests to 3rd party API’s. Direct API communications from JavaScript could be blocked in browsers, and it’s safer to store access tokens on the server.
  • Storing various add-in configurations for users or organizations.
  • Offline mailbox access. Often special workers are implemented to run in background when an add-in user is offline.

Aurinko aims to provide the necessary backend functionality for these add-ins so that developers could focus on the client code and the best user experiences.

  1. Host your client code on Netlify or Vercel (check out this comparison).
  2. Register your app with Aurinko.io (see the docs) and use api.aurinko.io as your app’s backend API (see the docs).
Aurinko model

Here is what you get with this model:

  1. User/session management based on openid or Outlook idToken. Simply confirm current user id using one of Aurinko’s oauth flows.
  2. OAuth access tokens are managed by Aurinko and refreshed automatically.
  3. Leverage Aurinko’s unified mailbox API, i.e. email tracking, meeting scheduling, …
  4. Build addins that can access other services. A number of CRM connectors are available now (Salesforce, SugarCRM, HubSpot, …), and more are being added. Ask us about adding a connector for your API.
  5. Manage your app from the Aurinko developer portal. See all connected users, their Organizations, and accounts.

This is our Outlook addin for Salesforce:

And by the way we deploy the same addin as a Chrome extension for Gmail users as the backend functionality is essentially the same.