diff --git a/src/Kore.php b/src/Kore.php
index 6a8766d..7610ad5 100644
--- a/src/Kore.php
+++ b/src/Kore.php
@@ -2,21 +2,17 @@
 
 namespace Kontrl\PhpKore;
 
-use phpseclib3\Common\Functions\Strings;
-use phpseclib3\Crypt\EC;
-use phpseclib3\Crypt\EC\PublicKey;
 use phpseclib3\Crypt\PublicKeyLoader;
-use phpseclib3\Crypt\RSA;
 
 class Kore
 {
     private $url = 'https://httpbin.org';
 
-    public function __construct() {}
+    public function __construct(public $privateKey) {}
 
-    public function signBody(string|array $body, string|array $key, string|bool $password = false)
+    public function signBody(string|array $body, string|bool $password = false)
     {
-        $privateKey = PublicKeyLoader::loadPrivateKey(base64_decode($key), $password);
+        $privateKey = PublicKeyLoader::loadPrivateKey(base64_decode($this->privateKey), $password);
         $sig = $privateKey->sign(json_encode($body));
         return base64_encode($sig);
     }
diff --git a/src/Pix.php b/src/Pix.php
new file mode 100644
index 0000000..e9c49f0
--- /dev/null
+++ b/src/Pix.php
@@ -0,0 +1,24 @@
+<?php
+
+namespace Kontrl\PhpKore;
+
+class Pix extends Kore
+{
+    public function newPixCharge($amount, $pix_key)
+    {
+        $payload = [
+            'amount' => $amount,
+            'pix_key' => $pix_key
+        ];
+        return curlRequest(
+            'https://httpbin.org/post',
+            'POST',
+            [],
+            [
+                'x-kore-drone-uid: drone:f8f19d43660d7bbdd2c63d428de6d7b1ff33554311adbe35c784b0584aa007fd',
+                'x-kore-drone-sign: ' . $this->signBody($payload)
+            ],
+            $payload
+        );
+    }
+}