Introducing API 2026-03-15
The 2026-03-15 version of the Omnisend API introduces a new versioning model, expanded resources, and updated response conventions designed for easier integration and clearer capabilities.
What's new in 2026-03-15
- Header-based versioning: The API version is specified via the
Omnisend-Version: 2026-03-15request header instead of the URL path. All 2026-03-15 endpoints share the base URLhttps://api.omnisend.com/api/. - New resources: Campaigns, Email Templates, Email Content, Email Universal Layouts, Images, Segments, and Analytics APIs are available under the
/api/base path. - Cursor-based pagination: List endpoints use opaque cursor tokens (
paging.cursors.after/paging.cursors.before) for efficient and consistent pagination across large datasets. - Standardized error responses: APIs return RFC 9457 Problem Details on failure — structured JSON with
type,title,status,detail, and an optionalerrorsarray for field-level validation failures.
API base URL
All 2026-03-15 endpoints use:
https://api.omnisend.com/api/Every request must include the version header:
Omnisend-Version: 2026-03-15Next steps
For detailed information on using 2026-03-15, refer to our comprehensive guides or browse the API reference in the sidebar. Don't hesitate to reach out to our support team if you have any questions.