Please read this manual for the basics in API calls. This manual contains information over API key location and overall rules:
General API docs directory are located here:
Repricing rules can take into account process prices, availability, promotions, etc. of stores, including data that you downloaded or we collected in custom fields.
Reprising scheme looks this way.
There are two options:
Each product block contains Suggested price and reprising Alerts.
Select all product for reprising, click reprice, after that all products will be sent to the reprising bucket.