[Wowfunhappy]

Of course, if the code wasn't available in the first place, the AI wouldn't be able to read it.

It wouldn't qualify as "open source", but I wonder if OP could have some sort of EULA (or maybe it would be considered an NDA). Something to the effect of "by reading this source code, you agree not to use it as training data for any AI system or model."

And then something to make it viral. "You further agree not to allow others to read or redistribute this source code unless they agree to the same terms."

[morpheuskafka]

My understanding is that you can have such an agreement (basically a kind of NDA) -- but if courts ruled that AI training is fair use, it could never be a copyright violation, only a violation of that contract. Contract violations can only receive economy damages, not the massive statutory penalties that copyright does.