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Version: 4.1 (2026 H2)

Office Web Add-In

The Office Web Add-In makes primedocs available in Word, Excel and PowerPoint in the browser (Microsoft 365 / office.com). It offers the same task pane as the Office Desktop Add-In.

note

The Web and Desktop Add-In are technically identical: they use the same manifest and the same generation endpoint. An Office.js add-in runs with the same manifest both in the Office desktop applications (Windows, macOS) and in Office in the browser.

Prerequisites​

  • Microsoft 365 with Office in the browser (office.com).
  • Reachability of the primedocs web application via HTTPS.
  • Distribution of the add-in via the Microsoft 365 Admin Center.
note

For the new Outlook in the browser, there is a separate add-in with its own manifest: Outlook (New).

Installation​

Installation is identical to the Desktop Add-In: configuration in the primedocs.config, generation of the manifest and distribution via the Microsoft 365 Admin Center. The full instructions are available here:

➜ Office Desktop Add-In: Installation

After distribution via the Microsoft 365 Admin Center, the add-in is automatically also available in Office in the browser. A separate step is not required.

If the add-in does not appear after distribution, see Troubleshooting: add-in rollout.

Single sign-on (Nested App Authentication)​

The web add-ins support single sign-on via Nested App Authentication (NAA). If an Office 365 auth provider with a ClientId is configured in the primedocs authentication provider, the add-in signs the user in automatically through their Microsoft 365 account, without a separate login. No dedicated feature flag is needed because the feature is active as soon as the ClientId is configured. If the Office host does not support the NestedAppAuth 1.1 requirement set, the add-in falls back to the regular sign-in.

A correspondingly configured Entra ID app registration is required (SPA redirect URI in the brk-multihub:// scheme, an exposed API with the access_as_user scope, pre-authorized Office hosts, admin consent). An Application ID URI in domain form is not required, as the Entra default is sufficient. The full instructions are available under Single Sign-On (SSO): App registration for add-in SSO.