Can't call the https://api.sandbox.paypal.com/v1/oauth2/token

[lsmpascal]

Hi.
I'm trying to call the https://api.sandbox.paypal.com/v1/oauth2/token to simply have a token.
I'm using php curl.

Here is my code : 

$curl = curl_init();
curl_setopt_array($curl, array(
CURLOPT_URL => "https://api.sandbox.paypal.com/v1/oauth2/token",
CURLOPT_RETURNTRANSFER => true,
CURLOPT_ENCODING => "",
CURLOPT_MAXREDIRS => 10,
CURLOPT_TIMEOUT => 30,
CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
CURLOPT_CUSTOMREQUEST => "POST",

CURLOPT_USERPWD => $PAYPAL_CLIENT_ID.":".$PAYPAL_SECRET,

CURLOPT_POSTFIELDS => "{\"grant_type\":\"client_credentials\"}",

CURLOPT_HTTPHEADER => array(
"Accept: application/json",
"Accept-Language: en_US"
),
));

The answer is : {"error":"unsupported_grant_type","error_description":"Grant Type is NULL"}
I checked and I simply use the grant type i've found here : https://developer.paypal.com/docs/api/get-an-access-token-curl/

I'm totally lost with the error, because it's the very beginning of my integration.

Thank you.

[MTS_Justin · Accepted solution]

Hello,

Your attempting to pass the item as a JSON object, which it's not.

It should be :

CURLOPT_POSTFIELDS => "grant_type=client_credentials",

Thanks !

[lsmpascal]

Hi. 

I don't know if your answer (for which I thank you !) is the solution, because after implementing it, I have another error : "NSS: client certificate not found (nickname not specified)".
Do you have any idear on this? 

[MTS_Justin]

Hello,

So if after adding the code I provided you're no longer experiencing the same error, then the code fixed the original issue.

This is confirmed by the new error you're experiencing, as whilst connecting to the sandbox endpoint a matching certificate for the endpoint cannot be found within the NSS store on your local machine.

You will need to add the sandbox certificate (api.sandbox.paypal.com) into your NSS store.

How to add a certificate into a NSS store : https://developer.mozilla.org/en-US/docs/Mozilla/Projects/NSS/tools/NSS_Tools_certutil

PayPal sandbox API certificates download : https://www.paypal.com/us/smarthelp/article/where-can-i-find-ssl-certificates-for-paypal-sandbox-api...

Thanks !

[lsmpascal]

I love detailed answers like yours.

Thank you so much !

[prlama]

Please help. Requesting by following giving me `Bad request`.

curl -X POST https://api.sandbox.paypal.com/v1/oauth2/token \ -H 'Authorization: Basic {Your Base64-encoded ClientID:Secret}=' \ -d 'grant_type=authorization_code&code={authorization_code}'

I encrypted `Base64-encoded ClientID:Secret` by btoa. authorization_code is used by capturing from redirect_url

[managepavans]

Hi,

I am also facing the same issue with getting access token at PayPal connect process. See code below:

Request Code:

$curl = curl_init();

$base_token = "{client_id: secret}";

$data = array(
    CURLOPT_URL => "https://api.sandbox.paypal.com/v1/oauth2/token",
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_CUSTOMREQUEST => "POST",
    CURLOPT_POSTFIELDS => array(
        'grant_type' => 'authorization_code',
        'code' => '{CODE}'
    ),
    CURLOPT_HTTPHEADER => array(
        "Authorization: Basic ".$base_token,
    ),
);
curl_setopt_array($curl,$data );
$response = curl_exec($curl);
curl_close($curl);

Response Code:

stdClass Object
(
    [name] => Bad Request
    [debug_id] => 2858088aa4473
    [message] => java.lang.IllegalArgumentException
    [details] => Array
        (
        )
)