I'm getting crazy with PHP curl and query string against Magento 2 REST Api. I have the following query:


coping and pasting it in the browser it works fine. If I use PHP and curl like in this example:

$curl = curl_init("http://mystore/rest/V1/products?searchCriteria[filter_groups][0][filters][0][field]=category_id&searchCriteria[filter_groups][0][filters][0][value]=10");
curl_setopt_array($curl, [
return curl_exec($curl);

Magento return an "Invalid signature" error. I found the problem, is the encoding of "&" character, but I tried using urlencode() or htmlentities(), I cannot find a solution. It works only substituting "&" with "& amp;" (without space), but the query is not correctly interpreted. Which is the correct way to send the query string using PHP curl?

1 Answer 1


Try following way:

$userData = array("username" => "admin", "password" => "admin123");
$ch = curl_init("http://mystore/index.php/rest/V1/integration/admin/token");
curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "POST");
curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($userData));
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, array("Content-Type: application/json", "Content-Lenght: " . strlen(json_encode($userData))));

$token = curl_exec($ch);

$ch = curl_init("http://mystore/index.php/rest/V1/products?searchCriteria[filter_groups][0][filters][0][field]=category_id&searchCriteria[filter_groups][0][filters][0][value]=10");
curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "GET");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, array("Content-Type: application/json", "Authorization: Bearer " . json_decode($token)));

$result = curl_exec($ch);

$result = json_decode($result, 1);
  • Thank you @sohel-rana, your example works fine. But doing the same thing, using OAuth instead of session based authentication, I obtain the "invalid signature" error. Do you have the same example with OAuth?
    – salgua
    Commented Oct 3, 2016 at 8:16
  • 'invalid signature' means you authentication is wrong. Check your authentication information.
    – Sohel Rana
    Commented Oct 3, 2016 at 8:30
  • Here is an example for oAuth: inchoo.net/magento-2/magento-2-api
    – Sohel Rana
    Commented Oct 3, 2016 at 8:32
  • 1
    I used the inchoo example, and it works fine. The problem is with query string. Without query string it works
    – salgua
    Commented Oct 3, 2016 at 10:03
  • Amazing this actually works, I've seen so many other similar examples that didnt so thanks so much !
    – AdamJones
    Commented Dec 13, 2018 at 15:07

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.