Hello,
Thank you for reaching out to Constant Contact API Developer Support.
Our API returns results in a paginated output. The response will include a URL that you then make another call to in order to get the next page of data. You would do this until you no longer get a "next" url. See this page in our documentation for details: https://v3.developer.constantcontact.com/api_guide/v3_technical_overview.html#paginated-output
Please let us know if you have any other questions!
Regards,
David B. Tier II API Support Engineer
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