I'd like to write Kotlin code server-side, with AP...

# announcements

[crummy]

I'd like to write Kotlin code server-side, with APIs that implement an interface, and auto-generate JS (or TS, even better) clients for my interfaces.
The idea is, if I needed data from the backend, I'd add a method to the interface, regenerate the clients, and now it's available for use. I'm not 100% sure how to go about this though.
One option I thought would be to use OpenAPI and maybe get Gradle to autogenerate clients. Is there a better way to do this?

[Hanno]

Don't know whats better, but i would try to use kotlinpoet and gradle to generate that into a common source set. And than compile kotlin to jvm and js :)

[Hanno]

Because it is a rather simple approach

[psh]

gRPC and GraphQL both provide mechanisms for specifying both your contract (the interface) and for generating the client code.

[crummy]

oh wow. kotlinpoet is cool, this would do it too

[crummy]

I've only ever used REST APIs so would prefer to stick with them but I have heard a lot about graphql. Will read up on it

[Tristan Blakers]

I hacked together a simple "Endpoint" class that defines the path/params/body/etc

[Tristan Blakers]

then just have JS/JVM API clients that consume that definition

[Tristan Blakers]

and use the definition to also define the endpoints in Spring from the class (using functional router), so endpoints are defined in one spot and fully type-safe server -> backend without code generation, and kotlinx.serialization doing the encording

[Tristan Blakers]

obviously this requires using KotlinJS, so it'd probably be too heavy unless you were using KotlinJS anyway

[Matteo Mirk]

OpenAPI is a great tool, but in this case you’ll have to write the templates for your client code, since its generators don’t support Kotlin frameworks last time I checked. You could use Ktor for both JS/JVM.

[crummy]

Ktor seems nice but I would still have to manually write my client right?

[Matteo Mirk]

Yes sort of, but you could create a template for OA that generates the Ktor client code needed, so you would achieve what you wanted. Alternatively you may want to try something similar to Feign, which is a Java lib that dynamically generates rest clients from an interface. I don’t know if there exists something kotlin-specific, but that would save you time avoiding manual coding. Last but not least you could try generating JS/TS clients directly from your OA specification:
• https://openapi-generator.tech/docs/generators
• https://openapi.tools/#sdk