Hubspot Webhooks: Redirect Auth & BAD_GRANT_TYPE Message

Question

I'm trying to add a custom app in Hubspot. I'm using PHP. I have:

A Hubspot app
A working webhook URL

A redirect URL with the following code

$url = 'https://api.hubapi.com/oauth/v1/token';
$code =  $_GET['code']; // Getting code parameter from redirect URL
//echo $code;
$fields = array();
$fields['grant_type'] = 'authorization_code'; // Have also tried 'refresh_token' - same result
$fields['client_id'] = '{CLIENT_ID}';
$fields['client_secret'] = '{CLIENT_SECRET}';
$fields['redirect_uri'] = '{REDIRECT_URI}';
$fields['code'] = trim($code);
//$fields['refresh_token'] = trim($code);  // Have also tried 'refresh_token' - same result

$request_type = 'POST';

$ch = curl_init($url);
curl_setopt($ch, CURLOPT_HTTPHEADER, array('Accept: application/json', $headers));
curl_setopt($ch, CURLOPT_HEADER, 0);
curl_setopt($ch, CURLOPT_CUSTOMREQUEST, POST); 
curl_setopt($ch, CURLOPT_TIMEOUT, 30);
curl_setopt($ch, CURLOPT_POST, 1);
if($fields){
    curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($fields));
}
curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);
$return = curl_exec($ch);
curl_close($ch);
echo var_dump ($return);

My understanding is that Hubspot will use the 'code' parameter passed to the on the "authorization" URL to validate the authorization. However, I keep getting this error:

string(171) "{"status":"BAD_GRANT_TYPE","message":"missing or unknown grant type","correlationId":"f0508752-24bc-40e4-b0bc-51e358459653","requestId":"96044613d4e4a5aab7356fab04001e5c"}"

user_8398691 · Answer

I had the same error response and it seemed that this is an encoding issue.

I debugged with Postman and found out that the following code works:

 "https://api.hubapi.com/oauth/v1/token",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 0,
  CURLOPT_FOLLOWLOCATION => true,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => "grant_type=authorization_code&code=string&redirect_uri=string&client_id=string&client_secret=string",
  CURLOPT_HTTPHEADER => array(
    "content-type: application/x-www-form-urlencoded",
    "Cookie: __cfduid=someidfrompostman"
  ),
));

$response = curl_exec($curl);

curl_close($curl);
echo $response;

Hubspot Webhooks: Redirect Auth & BAD_GRANT_TYPE Message

1 Answers