Release notes

V3 API Release Notes - September 2025

Updates and Feature Enhancements:

  • We’ve introduced significant improvements to Custom Fields, providing you with more control and flexibility when creating and managing custom data

  • We’ve added new guides to help you get started quickly with creating contacts and email campaigns

  • New Open Source SDKs are now available on GitHub to streamline your development process

  • Technology Partners: please update your applications to use the new Partner Authorization Request URL

The full release notes can be found in our V3 API documentation here:
V3 API Release Notes - September 2025