Hey. There's a few things here, and I'd be keen to chat about them in more detail - I'm marty at vyne dot co, or often on our slack - if you're keen to dive in

Hey. There's a few things here, and I'd be keen to chat about them in more detail - I'm marty at vyne dot co, or often on our slack - if you're keen to dive into anything further. > I’m sad to see that Taxi doesn’t support union/sum types! These are in progress right now. I'm not sure how well it fits your usecase, so it'd be interesting to chat. > For Kotlin, taxi could support this by generating sealed (data) class. That's a nice idea. We have a kotlin generator for taxi, but I hadn't gotten to how we would handle the union types. I feel like you just saved us a few iterations! :) > I’m also curious about how teams or systems onboard to Taxi. There’s a lot of advice about “models shouldn’t be shared between teams” and such. What we're advocating against here is a common domain model - where everyone in the org is expected to model a Customer in exactly the same way - this leads to everything being optional. In terms of onboarding, there's normally a few components: * A shared set of types (no models), describing in a taxi project, which lives in a git repo somewhere * Teams start describing their APIs using those types - either by publishing a Taxi model directly, or (more commonly), embedding the taxi types in their Swagger / Proto etc. * Teams then start querying using TaxiQL and a query server (like Vyne) to fetch data from across those APIs. This keeps the consumers decoupled from the producer schemas. > Finally, how should teams think about computed properties / expressions? [..] wouldn’t our API compute these properties internally? Yeah, it's uncommon for a producer contract to include a computed property - though we have seen teams do this against things like CSV models. It's more common for consumers to use these for declaring the computed result they want for a field in a query, and let the query service handle the computation. This allows either ad-hoc computation (defined in a field), or shared common expressions, defined as an expression type.