---
title: Backward compatibility in CMP
slug: content-marketing-platform/docs/backward-compatibility-in-cmp
docTags: 
createdAt: 2026-07-22T20:21:12.480Z
---

The following changes are backward compatible with Optimizely Content Marketing Platform (CMP) Open API:

- Add an endpoint or support for an HTTP method
- Add a field to the response payload
- Add an optional field to the request payload
- Add support for an optional query parameter
- Add a value to an enum
- Add support for an optional request header
- Add a response header