Deploying the Excel add-in for IT

This page is written for Office administrators and structured so that it can be worked through without follow-up questions. It may be passed on — and the best way to pass it on is this address:

https://sovrgpt.com/en/docs/excel-addin-it

There are two routes. The first is for regular operation, the second for environments in which the first is not available.

1. What you enter

A single address:

https://sovrgpt.com/xl/manifest.xml

That is the add-in's description file (an XML manifest). It is publicly reachable, requires no sign-in and rarely changes.

What does not happen: no software is installed on the workstations. The add-in is a web application that Excel shows in an embedded frame. Your users get a button in the ribbon — nothing more.

🔴 Do not open the manifest file in Excel and do not double-click it. Excel then takes an XML file for an XML expansion pack (a "smart document" from Office 2003) and reports that the security certificate is faulty. That message has nothing to do with the add-in: XML expansion packs have to be signed, Office web add-ins are never signed (see §10).

2. The route in the Microsoft 365 admin center

1. Open admin.microsoft.com and sign in with an account holding the Global Administrator or Exchange Administrator role.
2. Settings → Integrated apps
3. "Upload custom apps"
4. Choose "Office Add-in" as the app type.
5. Choose "Provide link to manifest file" and paste the address from §1.
6. Validate. The manifest is checked; errors are shown here.
7. Assign users — individual people, groups or the entire organisation.
8. Deployment type: please choose Fixed.
9. Finish.

After that your users have nothing to do. The next time they start Excel, the SovrGPT group with the Open assistant button appears on the right of the Home tab.

⏱️ Up to 72 hours until it is visible for all users. That is a property of Microsoft's distribution, not of our application.

• Publication on AppSource is not required.
• The route is intended by Microsoft for exactly this case (centralized deployment).

3. Prerequisites — please check first

These points determine whether the route in §2 is available to you at all. They come from Microsoft's own documentation on central deployment.

🔴 In sovereign and government clouds (such as Microsoft 365 Government) the "Integrated apps" page is sometimes missing. There the assignment runs through the classic Centralized Deployment page. The address to enter is the same.

4. When a policy is in the way

Two group policies can block the add-in. Both are on your side, not ours:

• "Block Web Add-ins" — registry value HKCU\Software\Policies\Microsoft\Office\16.0\WEF\TrustedCatalogs\disableallcatalogs = 1. If it is set, web add-ins are switched off entirely.
• "Let users access the Office Store" — affects the store route. It is not required for the central deployment in §2.

Check command for an affected workstation (PowerShell, no administrator rights required, changes nothing):

Get-ItemProperty -Path 'HKCU:\Software\Policies\Microsoft\Office\16.0\WEF\TrustedCatalogs' -ErrorAction SilentlyContinue

If there is no output, the policy is not set.

5. The single-machine route — when ① is not possible

For environments without a Microsoft 365 tenant (pure LTSC/perpetual), for pilots and for individual machines.

Direct downloads — both files are unsigned and in plain text:

The illustrated instructions for end users are at sovrgpt.com/en/excel — this is the link you pass to your users, not the file (see below).

What the file does — it is a text script, and you can read it before distributing it:

1. It downloads the manifest from https://sovrgpt.com/xl/manifest.xml to %LOCALAPPDATA%\SovrGPT\Excel\sovrgpt-excel-manifest.xml.
2. It checks that the downloaded file really is an add-in manifest (<OfficeApp) — and aborts otherwise.
3. It writes exactly one value under HKCU\Software\Microsoft\Office\16.0\WEF\Developer: the add-in ID as the name, the path to the manifest as the value.
4. It reads the value back and reports success or failure.

No administrator rights. No service. No autostart. No entry outside the user profile. The removal file reverses both.

Then at the workstation:

1. Close Excel completely — every window — and reopen it.
2. 🔴 In Excel, open Home → Add-ins, select SovrGPT für Excel there and press Add.
3. The Open assistant button is from now on permanently in the Home tab, in the SovrGPT group.

⚠️ Two honest limitations of this route:

• It triggers a Windows SmartScreen warning ("Windows protected your PC") because the file comes from the internet. That applies to every downloaded file of this type. More info → Run anyway.
• It cannot be delivered by e-mail: Outlook blocks .cmd, .bat, .reg, .exe and .msi on the level 1 block list — the recipient can neither open nor save it. Distribute the link, not the file — or put the file on a company drive or distribute it through your software deployment.

📌 Microsoft calls this route sideloading and points out that it is not intended for production use. For a trial it is suitable; for regular operation §2 is the right route.

Excel on the web

This requires a workbook in OneDrive or SharePoint. There is no Trust Center and no share for it: Home → Add-ins → More Add-ins → My Add-ins → Upload My Add-in → select the manifest → Upload.

6. Network and data protection

What must be reachable:

Both over HTTPS (443). The add-in needs no further allowances.

Where the data is processed: the application and database run in the EU, the language models on GPU capacity in EU data centres. The provider and controller is rooom AG (Jena); technical operation is supported by eNetworkers GmbH (Jena) on behalf of rooom AG. The full privacy policy: sovrgpt.com/datenschutz

What is sent from the workbook: not the file. The add-in creates a short description — sheet names, column headings, used ranges, formula patterns and a small sample of rows — and sends only that together with the user's instruction. With the "What is sent?" button every user can display exactly that text before submitting; the sample rows can be switched off.

The complete description of what is sent is in the user documentation.

7. What your users get

• A button in the Home tab → SovrGPT → Open assistant.
• The sidebar accepts an instruction in ordinary language ("calculate VAT in column D and highlight everything above €1,000").
• Nothing is written immediately. SovrGPT first shows a plan of changes in plain language. Out of the box every proposal waits for the user's approval; how often they are asked is their own setting.
• Undo restores the previous state — including on Office 2019 and 2021, where Microsoft's own one-click undo for add-ins is missing.
• Some purely visual changes (font, fill colour, borders) are marked in the preview as "Ctrl+Z only": they can be reverted with Excel's own undo, not with our button. The reason is an interface that does not exist on Office 2019.

Sign-in: on first start the user signs in with their SovrGPT account. The add-in receives an access of its own that applies exclusively to the Excel sidebar and can be revoked individually — explicitly not an API key of the organisation.

8. Supported Excel versions

The add-in requires only the smallest Excel API set and therefore loads on older perpetual versions too. Anything beyond that it checks at runtime and leaves out if it is missing — the user then gets a plain-language note instead of an error.

9. Updates

Improvements to SovrGPT take effect immediately and without any action on your part — the add-in is a web application, and the manifest only points at it.

Re-entering it is only necessary if the manifest itself changes (for example because a new ribbon button is added). We announce such cases in advance.

10. Why there is no certificate

Office web add-ins are not signed. Unlike VBA macros or old COM/VSTO add-ins there is no Authenticode procedure, no certificate to buy and no approval to obtain — an add-in is a web page plus an XML description.

The only certificate that counts is the TLS certificate of the domain, and sovrgpt.com brings that along.

11. Contact

Questions about deployment: through the contact routes named at sovrgpt.com/impressum to rooom AG. For a pilot we are happy to provide test accounts.