If you have a token and you want a session id that is unique to you then this feature is available for anyone with a token id.
{"msg":"redeem-server","instance_guid":"my_session_id_here","Title":"my application title","whitelist":0,"whitelisted":[],"passkey":"","root_passkey":"insert root password here","token_id":"insert token id here"}

The server will check if that token id exists and if so will create the session with the max client already set via the token you selected:
{"MSG":"instance_redeemed"}

If the session id selected has already been redeemed/created:
{"MSG":"instance_failed_to_redeem"}