# API v3 stops working

Calls to /v3/* on Omnisend API stop working on December 31, 2027.

Omnisend will sunset its v3 API on December 31, 2027. This removal affects all calls to /v3/* endpoints. After this date, requests to these endpoints will fail.

## What to use instead

Move to the v2026-03-15 API using the base path api.omnisend.com/api/ for contacts, products, categories, batches, and events. Requests require the Authorization header with Omnisend-API-Key and an Omnisend-Version header set to 2026-03-15.

- API: Omnisend API (api.omnisend.com)
- Kind: Removal
- Takes effect: December 31, 2027
- Calls after that day: fail
- Calls it hits: `/v3/*`
- Source: [Announcement](https://api-docs.omnisend.com/v3/reference)
- Verified: November 6, 2026, against Omnisend API's own pages
- Page: https://www.okapi.bot/providers/omnisend-api/breaking-changes/api-v3-stops-working/

## Omnisend API's words

> The v3 API is deprecated and will be sunset on December 31, 2027 .

Okapi finds the calls this change hits in your repo and opens the pull request with the fix: https://github.com/apps/okapi-agent