How does trpc typing work

export class API {
  private schema:z.ZodSchema = z.undefined()
  input<T>(inp:z.ZodSchema<T>){
    this.schema = inp
    return this
  }
  get(input:z.infer<typeof this.schema>){
    console.log(("ok"));
  }
}
const api = new API()
api.input(z.object({
  name:z.string()
}))

// I need a way to typically extract this {name:string} type without a codegen step

export class API {
  private schema:z.ZodSchema = z.undefined()
  input<T>(inp:z.ZodSchema<T>){
    this.schema = inp
    return this
  }
  get(input:z.infer<typeof this.schema>){
    console.log(("ok"));
  }
}
const api = new API()
api.input(z.object({
  name:z.string()
}))

// I need a way to typically extract this {name:string} type without a codegen step

const api = () => ({
  input: <T extends ZodTypeAny>(inputSchema: T) => ({
    mutate: <U>(mutateFn: (data: z.infer<T>) => U) =>
      (data: unknown) =>
        mutateFn(inputSchema.parse(data))
  })
})

// Create and use the api
const numberApi = api().input(z.number().min(1).max(10)).mutate(data => `Hello ${data}`)
const x = numberApi(9) // returns "Hello 9"
const y = numberApi(100) // throws Zod validation error since schema had max(10)

const api = () => ({
  input: <T extends ZodTypeAny>(inputSchema: T) => ({
    mutate: <U>(mutateFn: (data: z.infer<T>) => U) =>
      (data: unknown) =>
        mutateFn(inputSchema.parse(data))
  })
})

// Create and use the api
const numberApi = api().input(z.number().min(1).max(10)).mutate(data => `Hello ${data}`)
const x = numberApi(9) // returns "Hello 9"
const y = numberApi(100) // throws Zod validation error since schema had max(10)