@startuml
Client -> Server: POST /ping\nX-Server-Token: <JWT_TOKEN>\nX-Client-Token: <JWT_TOKEN>
Server -> Server: Validate client/server tokens
alt Success
    Server -> Server: Update last contact for peer ID
    Server -> Client: 204 No Content
else Invalid client or server token
    Server -> Client: 400 Bad request
else Peer not found
    Server -> Client: 401 Unauthorized
else Peer rejected
    Server -> Client: 403 Forbidden
else Unexpected error
    Server -> Client: 500 Server error
end

@enduml