We've released API v1.1. The API2Cart v1.0 API will
be supported until the end of 2018.
Use the customer filters to narrow down the returned data to only those you need. This way, you will also get the responses faster. Below is a request example with the part where filters go bolded:
https://api.api2cart.com/v1.0/customer.list.xml?api_key=<your_api_key>&store_key=<your_store_key>&start=0&count=4¶ms= <filters that you need separated by commas>
In the params field, use any of the filters listed below. To get all the fields allowed by the shopping cart in one response, use force_all.
System filter params: