[webarto]

Definiši malo šta podrazumjevaš pod proxy. Postoji par načina.

<?php

$url = 'https://api.500px.com/:request_uri';
$url = strtr($url, [':request_uri' => $_SERVER['REQUEST_URI'] . '?' . $_SERVER['QUERY_STRING']]);

if (filter_var($url, FILTER_VALIDATE_URL) === FALSE)
{
  die('Invalid URL');
}


if (empty($_GET['callback']))
{
  $_GET['callback'] = '__500px';
}

$json = file_get_contents($url);

header('Content-Type: application/json');

echo strtr(':callback(:json);', [':callback' => $_GET['callback'], ':json' => $json]);

Napravi poddomen, tipa 500px.example.com, postavi ovo kao index.php, i onda pozovi:
http(s)://500px.example.com/v1/users/show?consumer_key=PBhgzTKey5kF1XX3rl7idgYyRScBHAvq tbUOMAcd&username=zlatiborac&callback=dpt
Kao response, trebao bi dobiti:

dpt({"user":{"id":1275079,"username":"zlatiborac", "firstname":"Vladimir","lastname":"Markovic","birt hday":null,"sex":1,"city":"Zlatibor","state":"Serb ia","country":"Serbia","registration_date":"2012-08-26T07:09:55-04:00","about":"IT and photographer sort of person","domain":"zlatiborac.500px.com","fotomoto_ on":true,"locale":"en","show_nude":false,"fullname ":"Vladimir Markovic","userpic_url":"http://acdn.500px.net/1275079/c193ee21f8c7fd5cd3eaf9d73c3d0fb3cbaab41e/1.jpg?127","upgrade_status":0,"store_on":true,"con tacts":{"website":"www.dphotonews.com","twitter":" zlatiborac","tumblr":"zlatibor","flickr":"zlatibor ac"},"equipment":{"camera":["Canon 5D mark II"],"lens":["Canon 17-40 f4 L","Canon 100mm f2.8 L IS USM","Canon 70-200 f4 L IS USM"]},"photos_count":83,"affection":362,"in_favorites_ count":133,"friends_count":1,"followers_count":42, "avatars":{"default":{"http":"http://acdn.500px.net/1275079/c193ee21f8c7fd5cd3eaf9d73c3d0fb3cbaab41e/1.jpg?127","https":"https://gp1.wac.edgecastcdn.net/806614/avatars/avatars.500px.net/1275079/c193ee21f8c7fd5cd3eaf9d73c3d0fb3cbaab41e/1.jpg?127"},"large":{"http":"http://acdn.500px.net/1275079/c193ee21f8c7fd5cd3eaf9d73c3d0fb3cbaab41e/2.jpg?127","https":"https://gp1.wac.edgecastcdn.net/806614/avatars/avatars.500px.net/1275079/c193ee21f8c7fd5cd3eaf9d73c3d0fb3cbaab41e/2.jpg?127"},"small":{"http":"http://acdn.500px.net/1275079/c193ee21f8c7fd5cd3eaf9d73c3d0fb3cbaab41e/3.jpg?127","https":"https://gp1.wac.edgecastcdn.net/806614/avatars/avatars.500px.net/1275079/c193ee21f8c7fd5cd3eaf9d73c3d0fb3cbaab41e/3.jpg?127"},"tiny":{"http":"http://acdn.500px.net/1275079/c193ee21f8c7fd5cd3eaf9d73c3d0fb3cbaab41e/4.jpg?127","https":"https://gp1.wac.edgecastcdn.net/806614/avatars/avatars.500px.net/1275079/c193ee21f8c7fd5cd3eaf9d73c3d0fb3cbaab41e/4.jpg?127"}}}});

To možeš lako pozvati preko jQuery.getJSON