Excel.AllowedUrls added in Office.js beta (undocumented API)
UndocumentedNot in Microsoft's documentation
Excel.AllowedUrls, not in Microsoft's documentation, added on the Office.js beta CDN in 16.0.20606.15070, first seen 14 Oct 2026, 20:07 UTC. Affects Excel on Android, iOS, Mac, web and Windows. Not changed in production so far.
- Production
- No change seen on the production CDN.
- Beta
- added in 16.0.20606.15070, first seen 14 Oct 2026, 20:07 UTC; rollout complete 16 Oct 2026, 04:50 UTC.
What this means for your add-in
Excel.AllowedUrls appeared on the CDN.
It is not in Microsoft's documentation (neither @types/office-js nor @types/office-js-preview): an internal API that can change in any build. Do not depend on it; if you must, check that it exists before use — if (Excel.AllowedUrls) { … }.
So far this is only on the beta CDN (/lib/beta/hosted/). Add-ins that load production Office.js (/lib/1/hosted/) are not affected yet; production builds often follow beta.
Change history
Changed in the same rollouts
- Excel.Copilot added
- Excel.EntityCardLayoutType enum values
- Excel.SensitivityLabelAbacAttribute removed
- Excel.SensitivityLabelAbacAttributeValue removed
- Excel.SensitivityLabelUpdateResult removed
- Excel.SensitivityLabelUpdateStatus added
- Excel.UserActivityType enum values
- PowerPoint.SensitivityLabelAbacAttribute removed
- PowerPoint.SensitivityLabelAbacAttributeValue removed
- PowerPoint.SensitivityLabelUpdateStatus renamed
Source
silentship samples every Office.js file on the CDN every 10 minutes and compares the public API surface of each new build with the previous one by reflection. This page lists what changed for Excel.AllowedUrls; it does not include Microsoft's code. The API status comes from Microsoft's published type definitions (@types/office-js and @types/office-js-preview). Excel.AllowedUrls is not in Microsoft's documentation.