Thank you for reaching out to Constant Contact API Developer Support.
Constant Contact's API is RESTful, so as long as you are able to make HTTP calls with a JSON string, or receive them, you can make calls to our API to GET or POST data. While I'm not personally familiar with SSIS, I did find this page on the Microsoft Developer Network that you may be able to use alongside our API Documentation to accomplish this.
Please let us know if you have any other questions!
Tier II API Support Engineer