Upon successfully authenticating a client device with a server system, the client device and server system share auto-reconnect data. Upon subsequently losing and re-establishing communications with the server system, the client sends an auto-authenticate request to the server. The auto-authenticate request includes a session verifier that is based at least in part on the shared auto-reconnect data. The server validates the session verifier. If the validation is successful, the server automatically re-authenticates the client device.