syntax "proto3"; package session; service SessionService { rpc Login(LoginRequest) returns (LoginResponse) {} rpc Logout(LogoutRequest) returns (LogoutResponse) {} } message LoginRequest { string username = 1; string password = 2; } message LoginResponse { string token = 1; string err_msg = 2; } message LogoutRequest { string token = 1; } message LogoutResponse { string err_msg = 1; }