Version 2 (Json)
A few policies are relevant for this: REST Policies
Policy "restActive" must be true.
Policy "restBasicAuthentication" must be true to allow Basic authentication See wikipedia
If REST calls are made from the browser via a logged-in user and Basic auth is not used, the calls will be made with the credentials of the user.
Download the swagger file from:
https://<server>/<application>/rest/v2/swagger.jsonYou can browse and try the api, using the built in SwaggerUI (from version 9147):
https://<server>/<application>/rest/v2/swagger
GET examples:
Single:
https://<server>/<application>/rest/v2/<entity>/<DataID>List:
https://<server>/<application>/rest/v2/<entity>