It is just a noop, but here it looks very appropriate/readable because it reads as saying "AI will fill this in".

The same as “pass”?

It's a misuse of the Python Ellipsis, though PEP has no opinion on it. The Ellipsis is "Special value used mostly in conjunction with extended slicing syntax for user-defined container data types."

In other words, it happens to work and look neat, but pass is the correct way to do it.

Ellipses is actually used in quite a few places. See the answers and comments on this stackoverflow post[0]. The usage most similar to what I have in the magentic examples is with the `@overload` decorator in the typing module[1].

With that said, you are free to put any code in the function body including `pass` or just a docstring or even `raise NotImplementedError` - it will not be executed. Using Ellipses satisfies VSCode/pyright type checking and seemed neatest to me for the examples and docs. I have some additional notes on this in the README[2].

[0] https://stackoverflow.com/q/772124/9995080

[1] https://docs.python.org/3/library/typing.html#typing.overloa...

[2] https://github.com/jackmpcollins/magentic#type-checking