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Security Trimming and REST

Security trimming is an important feature in SharePoint. The permissions defined in a site is "respected" throughout the site including the APIs. So once you define a permission, wherever you navigate, the permissions are applied and accordingly you will (not) see the data.

What does it also mean that if you are using REST API to fetch data from a SharePoint site, the API returns data with security trimmed. So you don't have to apply any additional filter to the query. The same query might return 10 items for one user, 20 items for another user based on the user's permission on items.

Also, let us say, you are trying to get a list of Apps (Libraries and Lists) from a site using REST and you are displaying that on a page. Also assume that you have not given permission to 5 out of 10 Apps to the user "User A".

How many Apps User A get to see in a page? It's not 5 but all. Remember, this is similar to the case where user navigate to Site Contents page and user can see the complete list of Apps regardless of having permission to an App or not. Only when user clicks on an App where user does not have access, it shows Access Denied message.

So even in this case REST works as expected. Hope this will clear any doubts around security trimming in REST API.

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