Answer - Yes, ExperienceBank allows to map several activities with one GYG activity.
Answer - Yes, you can connect your several Booking system accounts with one GYG account.
Answer - For now GYG takes Prices, availability, and their Cut-off time from the ExperienceBank.
Answer - Yes, GYG takes prices from ExperienceBank Via API. Supplier Can enable and disable this function on GYG.
Answer - Once a day fetching 90 days availability in advance and Once a week fetching 365 days availability in advance.
Answer - Yes, GYG supports opening hours via API.
Answer - ExperienceBank needs a CSV file from GYG to import your GYG product on ExperienceBank and Map on it.
Answer - You can see a maximum of 365 days of availability on the GYG website.
No, GYG doesn't support custom fields over API.
Click on the link to open the GYG article in which you can understand - How to enable price over API?