Endpoints in the "Preview" category are beta releases of new APIs before they become part of the official MURAL API.
Preview endpoints can be modified or removed at any time without releasing a new version of the API. For this reason, developers shouldn't ship apps that call preview endpoints.
To access a preview endpoint, include the following header in your request:
Accept: vnd.mural.preview
Without this header, calls will fail with a 406 Not Acceptable error.