testbed/deepset-ai__haystack/releasenotes/notes/deprecate-method-to-openai-format-fb2538cf3f610d2a.yaml

---
deprecations:
  - |
    Deprecate the method `to_openai_format` of the `ChatMessage` dataclass.
    This method was never intended to be public and was only used internally.
    Now, each Chat Generator will know internally how to convert the messages to
    the format of their specific provider.