How do I add/edit contacts with the API?

The contact_sync API call allows you to add or edit a contact based on their email address. You can use this single call to to add/edit contacts, rather than using the two step process of calling contact_view to see if a contacts exists, then calling contact_add or contact_edit to add or edit your contacts.

This API call uses a POST method and the supported output formats are xml, json, and serialize. For more information about the contact_sync API call, please see this API document.