Question

I am writing a WordPress plugin that uses WP_HTTP for making an API call.

The code is as below:

$request = new WP_Http;
$headers = array(
    'Content-Type: application/x-www-form-urlencoded', // required
    'accesskey: abcdefghijklmnopqrstuvwx', // required - replace with your own
    'outputtype: json' // optional - overrides the preferences in our API control page
);
$response = $request->request('https://api.abcd.com/clients/listmethods', array( 'sslverify' => false, 'headers' => $headers ));

But I am getting the response as “406 Not Acceptable”.

When I tried using cURL for the above request the request was successful.

Answer 1

The 406 error indicates the web service probably isn’t recognizing your Content-Type header, so it doesn’t know what format it’s responding to. Your $headers variable should be an associative array, like this:

$headers = array(
  'Content-Type' => 'application/x-www-form-urlencoded', 
  'accesskey' => 'abcdefghijklmnopqrstuvwx',
  'outputtype' => 'json');

or a string that looks like a raw header (including newlines), like this:

$headers = "Content-Type: application/x-www-form-urlencoded \n 
  accesskey: abcdefghijklmnopqrstuvwx \n
  outputtype: json";

The WP_Http class will convert a raw header string into an associative array, so you’re nominally better off just passing it an array in the first place.