ECS field for client id

Hi, is there any field available for a client id or client name in machine 2 machine scenario's?
I see options for user, or ip, but not something like a client id.
Goal is to have usage insights per consumer based on incoming requests.

I think the client.domain field fits this use case?

This value may be a host name, a fully qualified domain name, or another host naming format. The value may derive from the original event or be added from enrichment.