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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; 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, Application ID URI, pre-authorized Office hosts, admin consent). These steps are mandatory; the full instructions are available under Single Sign-On (SSO) — App registration for add-in SSO.