[throw3982]

But in this case their customers want specific features that would be integrated in their own SaaS product.

How would that work, am I misunderstanding something?

[detaro]

Not necessarily they same customers as the ones that already have made feature demands (ideally you'd find more while doing this!), or if them, then consult on the entire integration, not just the features in the app they requested.

[throw3982]

I get it the consulting on the integration but on the features, the first customers that request a particular feature would own the code for it.

[detaro]

No, that you would exclude in the contract so you keep it. If and to what terms of course depends on the specific case, as a new startup you'll have to give something.