Thank you for reaching out to Constant Contact API Developer Support. My team is here to assist outside software developers with questions about building into Constant Contact's API.
We are currently in the process of deprecating the V1 API, but there’s not an ETA as to when it will be fully completed. When a particular integration/key is scheduled to be retired, accounts using the integration are notified by email and advised when the key will be deprecated. Due to this, if you’re still using an integration built on the Legacy API, we recommend upgrading to V3 at your earliest convenience.
Courtney E. API Support Specialist
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