Sumac does some some APIs for specific programs. For example, Sumac has an API defined for integrating with QuickBooks accounting software, and for MailChimp and Constant Contact for email marketing.
Otherwise, no, Sumac does not provide any APIs. Having said that, Sumac does have the ability to export data from any list (to either a .csv or .txt file), so you can easily get data out of Sumac to bring into any other system.
In addition, Sumac also has built-in importing tools, so you're able to import data from other systems as well!
If you plan on importing data on a routine basis, consider using Universal Import! This helpful tool allows you to save your import preferences so that it is quick and easy to import data any time. Check out
this article to learn more about setting up Universal Import.