title: using POST JSON data with PHP cURL. Cannot get response
body: <p>Hi I'm trying to POST some data in an array using JSON to receive a response and output the response.  So far I have followed all the parameters closely but it fails to fetch the data.</p>
  
  <p>I am using the Coinbase API to 'generate' a button 
  <a href="https://coinbase.com/api/doc/1.0/buttons.html" rel="nofollow">https://coinbase.com/api/doc/1.0/buttons.html</a></p>
  
  <p>I have also put the correct API in the $ch variable below as per this page</p>
  
  <p><a href="https://coinbase.com/docs/api/authentication" rel="nofollow">https://coinbase.com/docs/api/authentication</a></p>
  
  <p>It fails to fetch anything back.  I have posted the correct details to get a response with some data but it fails, any ideas?</p>
  
  <p>Here is my code</p>
  
  <pre><code>&lt;?php
  $data = array(
    "button" =&gt; array(
      "name" =&gt; "Product Name",
      "price_string" =&gt; "1.23",
      "price_currency_iso" =&gt; "USD",
      "custom" =&gt; "Order 123",
      "description" =&gt; "Sample description",
      "type" =&gt; "buy_now",
      "style" =&gt; "custom_large"
    )
  );                                                                    
  
  $json_data = json_encode($data);                                                                                   
  
  
  $ch = curl_init('https://coinbase.com/api/v1/buttons?api_key=MYAPIKEY');                                                                      
  curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "POST"); 
  curl_setopt($ch, CURLOPT_HEADER, false);
  curl_setopt($ch, CURLOPT_POSTFIELDS, $json_data);                                                                  
  curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);                                                                      
  curl_setopt($ch, CURLOPT_HTTPHEADER, array(                                                                          
  'Content-Type: application/json',                                                                                
  'Content-Length: ' . strlen($json_data))                                                                       
  );                                                                                                                   
  
  $output = curl_exec($ch);
  
  $result = json_decode($output);
  
  echo $result-&gt;button-&gt;type;
  
  ?&gt;
  </code></pre>