Use CodeGen to generate Type Definitions for other languages (like Swift/Kotlin)

[pedroalonsoms]

Let's say I create an endpoint like this:

https://myapp.com/api/posts/user/123

Then TanStack router will generate the necessary type definitions to hit this endpoint in TypeScript.

Can we make it so that the type definitions are also generated/translated for Swift and Kotlin languages ?

This way, by creating the API's in TypeScript, we would be able to hit these endpoints for mobile apps as well (with type-safety).

gRPC does this in a similar way, except that it requires a schema.proto file, which is redundant if we already have the typescript definitions (we can just translate them to other languages)

TypeScript (generated by TanStack)

type User = {
  email: string;
  age: number;
  password: string;
};

Kotlin (translated)

data class User(
    val email: String,
    val age: Int,
    val password: String
)

Swift (translated)

struct User {
    let email: String
    let age: Int
    let password: String
}

What do you think?

[schiller-manuel]

this would only make sense for API routes, right? a more scalable approach would be to generate Open API for which a lot of code gen tools exist

[pedroalonsoms]

Yes, this would be targeted to API routes (for RPC methods it doesn't make much sense).

We can use OpenAPI/Swagger tooling but it requires to manually re-define the types.

My idea was to automatically generate the Kotlin/Swift types based on the TypeScript types (we don't need to re-define them in a yaml file).

Another alternative would be to automatically generate this YAML file from the TypeScript types (i don't know if this is what you mean)

This is how we could do it in OpenAPI/Swagger:

openapi: 3.0.0
info:
  title: Example API
  version: 1.0.0
servers:
  - url: https://api.example.com/v1
paths:
  /users:
    get:
      summary: Get all users
      operationId: getUsers
      responses:
        "200":
          description: List of users
          content:
            application/json:
              schema:
                type: array
                items:
                  type: object
                  properties:
                    id:
                      type: integer
                    name:
                      type: string

[schiller-manuel]

yeah the generation of the yaml would be the idea.

[downright-development]

would love this TBH - or to better understand how to run TSS in a monorepo alongside something like expo RN.