Metrics can only be incremented by registered service applications. To register your application for this privilege, please get in touch with the Trovi developers.
The metrics endpoint is unique, in that callers must authenticate as the client application itself, and pass the user's token via the origin URL parameter. The reason for this is because we don't want users to be able to freely increment metrics as they please, so we only allow registered clients to do so, but we still require the user token in order to ensure that the user has permission to interact with the Artifact in the way that would increase the relevant metric.
