get_flight_cost(travel_from='RMS', travel_to='JFK', travel_date='2024-12-01', travel_class='first')
compute_exchange_rate(base_currency='RMB', target_currency='USD', value=10000.0)
set_budget_limit(access_token='abc123', budget_limit=1428.57)
book_flight(access_token='abc123', card_id='card_3456', travel_date='2024-12-01', travel_from='RMS', travel_to='JFK', travel_class='first')
retrieve_invoice(access_token='abc123', booking_id='3426812')