Learn how to authenticate, how data is stored, and how to make your first API calls.
Klaviyo's new and improved APIs are now available! Start building today!
Explore our previous API documentation. The v1/v2 legacy APIs are scheduled to be end-of-lifed on Jan 1, 2024.
Learn about the differences between our v1/v2 APIs and our new APIs with this comprehensive comparison chart.JSON:API Relationships
The new API surface now supports a thorough set of syntax for modeling relationships between resources. Learn more about using relationships.JSON:API Filtering
JSON API’s general filtering syntax and its supported operations can be used across all new APIs.