Sharepoint - REST: set ReadSecurity / WriteSecurity (Item Level Permissions)

It is possible to set or update ReadSecurity or WriteSecurity using REST API and JSOM both.

REST API

Request body

{
  "__metadata": {
    "type": "SP.List"
  },
  "ReadSecurity": 2,
  "WriteSecurity": 4
}

End-point

/_api/web/lists/getbytitle('{List Name}')

You need to make an UPDATE request to above end-point with above request body. I have tested it using My SP REST Client.

More about ReadSecurity & WriteSecurity

ReadSecurity & WriteSecurity do not appear in response when you make a GET request to the list end-point but it returns all properties those are mentioned in MSDN. I mean following end-point

/_api/web/lists/getbytitle('{List Name}')

But if use $select operator in your query, then you will get the value of ReadSecurity & WriteSecurity. I mean following

/_api/web/lists/getbytitle('{List Name}')?$select=ReadSecurity,WriteSecurity

The reason is: these (ReadSecurity & WriteSecurity) properties are not returned with the resource. See more on Getting properties that aren't returned with the resource.

JSOM

Set value using

yourList.set_readSecurity(2)
yourList.set_writeSecurity(4)

Get value using

yourList.get_readSecurity()
yourList.get_writeSecurity()