package main

import (
	"encoding/json"
	"fmt"
)

type Code struct {
	Id   int
	Desc string `json:"description"`
} 

func main() {
	var response = `{
	"data": {
		"items": [
  		{
			"code": {
				"id": 42,
	    			"description": "The meaning of life"
  			}
		}]
	}}`

	var r = struct {
		Data struct {
			Items []struct{
				Code Code
			}
		}
	}{}
	
	_ = json.Unmarshal([]byte(response), &r)
	fmt.Printf("%v\n", r.Data.Items[0])
}