What’s new and what’s changed in SharePoint Online REST API in September 2018
A few months ago I’ve created a site, where you can explore SharePoint REST API - SharePoint REST API Metadata Explorer. With REST API explorer you can navigate between different endpoints, explore their structure, methods, classes and parameters. REST API explorer uses _api/$metadata endpoint to get the REST API data, parses it and presents in tree view format. REST API explorer also stores historical $metadata results in Azure storage making it possible to compare $metadata results we have today and month ago. I’ve added a new section to REST API explorer called SharePoint REST API Change Log. With change log you can explore what was changed in SharePoint APIs in the last few months.
The full list of all changes you can find here (September tab). This post contains some highlights about changes introduced in last month.
Please note, that all changes are gathered from Targeted tenant. Most likely this changes haven’t been officially introduced yet, use this post as spoilers to potential upcoming features. If you want to use APIs mentioned here, please check corresponding official documentation to make sure they are available.
Root functions changes (_api/)
First of all companyportal API and corresponding types were removed. I haven’t found any relevant information about this API, most likely that was kind of experiment, because this API was added in August and now deleted in September. However a new endpoint was added called OrgNewsSite. That looks interesting, because OrgNewsSite stands for organization news. It seems that some work is in progress around organization news APIs.
Marc D Anderson @sympmarc pointed out that there were some updates around Organizational news and demo on Ignite. Checkout links he provided - What’s new for your intranet in Office 365 and Microsoft SharePoint Improvements Announced at Ignite.
The method returns Microsoft.SharePoint.OrgNewsSite.OrgNewsSiteApi type, which has only one function called Details. Details returns nothing but SiteId, WebId and Url. I assume that the development is still in the early stage, however we might expect some announcements about org news api in the nearest future 
. My guess is that companyportal was simply renamed to OrgNewsSite.
SP.Publishing.PublishingSite function was deleted and Microsoft.Online.SharePoint.MultiGeo.Service.TenantRenameJob was added. I’m not aware of what the first one means, but tenant rename job sounds interesting. Will we be able to rename tenant? I don’t think so… maybe some aspects of tenant… who knows, will see
Entity changes
Microsoft.Office.Server.Search.REST.SearchRequest – added new property PropertiesToGenerateAcronyms (array of strings). Might be useful for guys working with search api heavily.
A lot of companion classes were added regarding tenant rename job mentioned earlier. For example endpoint
A few more changes were introduced into the SP namespace. For example there is a new method called SetUserAsOwner – you can set a user as a group owner. SP.RenderListDataParameters type received additional property called AudienceTarget (boolean) – it seems we will have an option to return targeted data from list! Bbased on Office 365 roadmap this property was added to support audeince targeted news.
Use API Changelog to explore other differences which were added in September.