An Office service that supports add-ins to interact with objects in Office client applications.
Dear Sharon,
From my research, the @microsoft/office-js package is published under the official Microsoft npm scope, but the package itself is deprecated and no longer supported. A new 1.0.0 release with a lower version number than 1.1.110 is unusual, and I wasn't able to find any official announcement explaining it. Until the maintainers confirm it, I'd recommend not treating it as a supported release.
You can check its details yourself by running npm view @microsoft/office-js to see the publish date, the dist tags, and the publishing account. For your add-ins, the recommended approach is to load Office.js from the official Microsoft CDN rather than the npm package.
For authoritative confirmation about the unexpected publication, please open an issue in the OfficeDev/office-js repository and include the 1.0.0 publication date, npm dist-tags, and registry metadata. This will help the maintainers look into it quickly.
If you get a response there, feel free to share it here so others with the same question can benefit. Have a wonderful day.