Dart

import 'package:http/http.dart' as http;
import 'dart:convert';

main() async {
  final url = Uri.parse('<https://httpbin.org/anything>');
  final response = await http.read(url);
  final data = json.decode(response);
  print(data['headers']['User-Agent']);
}

Go

package main

import (
	"encoding/json"
	"fmt"
	"net/http"
)

func main() {
	url := "<https://httpbin.org/anything>"
	response, _ := http.Get(url)

	var data map[string]map[string]interface{}
	json.NewDecoder(response.Body).Decode(&data)
	response.Body.Close()

	fmt.Println(data["headers"]["User-Agent"])
}

JavaScript

const url = '<https://httpbin.org/anything>'
const response = await fetch(url)
const data = await response.json()
console.log(data['headers']['User-Agent'])

Ruby

require 'uri'
require 'net/http'
require 'json'

url = URI('<https://httpbin.org/anything>')
response = Net::HTTP.get(url)
data = JSON.parse(response)
puts data['headers']['User-Agent']