lowprodbeta

OfficeCore.FlightingService.getABConfigs added in Office.js production and beta (undocumented API)

UndocumentedNot in Microsoft's documentation

OfficeCore.FlightingService, not in Microsoft's documentation, getABConfigs added on the Office.js production CDN in 16.0.20619.15190, first seen 26 Oct 2026, 18:50 UTC. Affects Excel on iOS, Mac, web, Windows and Android, OneNote on iOS, Mac and web, PowerPoint on Windows, iOS and web, Visio on web and Windows and Word on web and iOS.

Production: getABConfigs added in 16.0.20619.15190, first seen 26 Oct 2026, 18:50 UTC; rolling out, on 4% of sampled edges.
Beta: getABConfigs added in 16.0.20619.15190, first seen 26 Oct 2026, 19:00 UTC; rolling out, on 5% of sampled edges.

What this means for your add-in

OfficeCore.FlightingService.getABConfigs 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 (OfficeCore.FlightingService) { … }.

Change history

Change

Build

Severity

Hosts

getABConfigs added

function undocumented

16.0.20619.15190

beta 26 Oct 2026, 19:00 UTC

Rolling out · 5%

low

Excel on iOSExcel on MacExcel on webExcel on WindowsOneNote on iOSOneNote on MacPowerPoint on WindowsVisio on webWord on web

getABConfigs added

function undocumented

16.0.20619.15190

prod 26 Oct 2026, 18:50 UTC

Rolling out · 4%

low

Excel on AndroidExcel on iOSOneNote on webPowerPoint on iOSPowerPoint on webVisio on webVisio on WindowsWord on iOS

Changed in the same rollouts

Word.LineFormat removed
OneNote.ServiceId enum values

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 OfficeCore.FlightingService; 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). OfficeCore.FlightingService is not in Microsoft's documentation.