compute_exchange_rate(base_currency='USD', target_currency='EUR', value=1500.0)
book_flight(access_token='abc123xyz456', card_id='card5638', travel_date='2024-07-01', travel_from='SFO', travel_to='BOS', travel_class='business')
retrieve_invoice(access_token='abc123xyz456', booking_id='3426812')
contact_customer_support(booking_id='3426812', message='Require assistance with transaction particulars')
message_login(user_id='USR100145')
send_message(receiver_id='travel_advisor', message='Details regarding problems faced with the flight booking transaction.')