Ask HN: What comp should a tech co-founder ask for?

Do any tech co-founders on here have experience/example comp structures suitable for joining an early stage project?

I want to build their product but they haven't got funding yet.

Unsure how common it is to take just stock/a mix/an agreed cash payment once funding happens etc.

Considering spending 20 hrs per week one of two chosen projects to spread my risk pre-funding, unsure if this is acceptable either, though.