diff --git a/Openpay/Data/Openpay.php b/Openpay/Data/Openpay.php
index 8287d27..525305d 100644
--- a/Openpay/Data/Openpay.php
+++ b/Openpay/Data/Openpay.php
@@ -1,74 +1,109 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Openpay\Data;
 
+/**
+ * Openpay SDK credential holder (Nowo fork).
+ *
+ * Credentials are process-global statics (upstream SDK design). Callers must use
+ * {@see configure()} / {@see getInstance()} per logical operation and {@see reset()}
+ * afterwards so merchant keys never leak across HTTP requests — including under
+ * php-fpm workers and FrankenPHP ZTS / worker mode.
+ */
 class Openpay
 {
-
     private static $instance = null;
-    private static $id;
-    private static $apiKey;
+
+    private static $id = null;
+
+    private static $apiKey = null;
+
     private static $userAgent = '';
-    private static $country;
-    private static $apiEndpoint = '';
-    private static $apiSandboxEndpoint = '';
-    private static $sandboxMode = true;
+
+    private static $country = null;
+
+    private static string $apiEndpoint = '';
+
+    private static string $apiSandboxEndpoint = '';
+
+    private static bool $sandboxMode = true;
+
     private static $classification = '';
-    private static $publicIp;
 
-    public function __construct()
+    private static $publicIp = null;
+
+    /**
+     * Clears all merchant credentials and endpoint state.
+     * Safe to call between requests / after each API session.
+     */
+    public static function reset(): void
     {
+        self::$instance             = null;
+        self::$id                   = null;
+        self::$apiKey               = null;
+        self::$userAgent            = '';
+        self::$country              = null;
+        self::$apiEndpoint          = '';
+        self::$apiSandboxEndpoint   = '';
+        self::$sandboxMode          = true;
+        self::$classification       = '';
+        self::$publicIp             = null;
+    }
 
+    /**
+     * Overwrites static credentials for the next API calls (no merge with previous merchant).
+     */
+    public static function configure(string $id, string $apiKey, string $country = 'MX', string $publicIp = '127.0.0.1'): void
+    {
+        self::$id        = $id;
+        self::$apiKey    = $apiKey;
+        self::$country   = $country;
+        self::$publicIp  = $publicIp;
+        self::setEndpointUrl($country);
     }
 
-    public static function getInstance($id, $apiKey, $country, $publicIp)
+    public static function getInstance(string $id, string $apiKey, ?string $country = '', ?string $publicIp = null)
     {
-        if ($id != '') {
-            self::setId($id);
-        }
-        if ($apiKey != '') {
-            self::setApiKey($apiKey);
-        }
-        if ($country != '') {
-            self::setCountry($country);
-            self::setEndpointUrl($country);
-        }
-        if(!is_null($publicIp)){
-            self::setPublicIp($publicIp);
-        }
-        $instance = OpenpayApi::getInstance(null);
-        return $instance;
+        $country  = ($country !== null && $country !== '') ? $country : 'MX';
+        $publicIp = $publicIp ?? '127.0.0.1';
+
+        self::configure($id, $apiKey, $country, $publicIp);
+
+        return OpenpayApi::createRoot();
     }
 
-    public static function setUserAgent($userAgent)
+    public static function setUserAgent($userAgent): void
     {
-        if ($userAgent != '') {
+        if ($userAgent !== '')
+        {
             self::$userAgent = $userAgent;
         }
     }
 
     public static function getUserAgent()
     {
-        $userAgent = self::$userAgent;
-        return $userAgent;
+        return self::$userAgent;
     }
 
-    public static function setClassificationMerchant($classification)
+    public static function setClassificationMerchant($classification): void
     {
-        if ($classification != '') {
+        if ($classification !== '')
+        {
             self::$classification = $classification;
         }
     }
 
     public static function getClassificationMerchant()
     {
-        $classification = self::$classification;
-        return $classification;
+        return self::$classification;
     }
 
-    public static function setApiKey($key = '')
+    public static function setApiKey($key = ''): void
     {
-        if ($key != '') {
+        if ($key !== '')
+        {
             self::$apiKey = $key;
         }
     }
@@ -76,103 +111,122 @@ public static function setApiKey($key = '')
     public static function getApiKey()
     {
         $key = self::$apiKey;
-        if (!$key) {
-            $key = getenv('OPENPAY_API_KEY');
+
+        if (!$key)
+        {
+            return getenv('OPENPAY_API_KEY');
         }
+
         return $key;
     }
 
-    public static function setId($id = '')
+    public static function setId($id = ''): void
     {
-        if ($id != '') {
+        if ($id !== '')
+        {
             self::$id = $id;
         }
     }
 
-    public static function setCountry($country = '')
+    public static function setCountry($country = ''): void
     {
-        if ($country != '') {
+        if ($country !== '')
+        {
             self::$country = $country;
         }
     }
 
     public static function getCountry()
     {
-        $country = self::$country;
-        return $country;
+        return self::$country;
     }
 
     public static function getId()
     {
         $id = self::$id;
-        if (!$id) {
-            $id = getenv('OPENPAY_MERCHANT_ID');
+
+        if (!$id)
+        {
+            return getenv('OPENPAY_MERCHANT_ID');
         }
+
         return $id;
     }
 
-    public static function setPublicIp($publicIp = null)
+    public static function setPublicIp($publicIp = null): void
     {
-        if (!is_null($publicIp)) {
+        if (null !== $publicIp)
+        {
             self::$publicIp = $publicIp;
         }
     }
 
-    public static function getPublicIp() {
+    public static function getPublicIp()
+    {
         return self::$publicIp;
-
     }
 
     public static function getSandboxMode()
     {
-        $sandbox = self::$sandboxMode;
-        if (getenv('OPENPAY_PRODUCTION_MODE')) {
-            $sandbox = (strtoupper(getenv('OPENPAY_PRODUCTION_MODE')) == 'FALSE');
+        if (getenv('OPENPAY_PRODUCTION_MODE'))
+        {
+            return strtoupper(getenv('OPENPAY_PRODUCTION_MODE')) === 'FALSE';
         }
-        return $sandbox;
+
+        return self::$sandboxMode;
     }
 
-    public static function setSandboxMode($mode)
+    public static function setSandboxMode($mode): void
     {
-        self::$sandboxMode = $mode ? true : false;
+        self::$sandboxMode = (bool) $mode;
     }
 
-    public static function getProductionMode()
+    public static function getProductionMode(): bool
     {
         $sandbox = self::$sandboxMode;
-        if (getenv('OPENPAY_PRODUCTION_MODE')) {
-            $sandbox = (strtoupper(getenv('OPENPAY_PRODUCTION_MODE')) == 'FALSE');
+
+        if (getenv('OPENPAY_PRODUCTION_MODE'))
+        {
+            $sandbox = (strtoupper(getenv('OPENPAY_PRODUCTION_MODE')) === 'FALSE');
         }
+
         return !$sandbox;
     }
 
-    public static function setProductionMode($mode)
+    public static function setProductionMode($mode): void
     {
-        self::$sandboxMode = $mode ? false : true;
+        self::$sandboxMode = !(bool) $mode;
     }
 
-    public static function setEndpointUrl($country)
+    public static function setEndpointUrl($country): void
     {
-        if ($country == 'MX') {
-            if (self::getClassificationMerchant() != 'eglobal') {
-                self::$apiEndpoint = 'https://api.openpay.mx/v1';
+        if ($country === 'MX')
+        {
+            if (self::getClassificationMerchant() !== 'eglobal')
+            {
+                self::$apiEndpoint        = 'https://api.openpay.mx/v1';
                 self::$apiSandboxEndpoint = 'https://sandbox-api.openpay.mx/v1';
-            } else {
-                self::$apiEndpoint = 'https://api.ecommercebbva.com/v1';
+            }
+            else
+            {
+                self::$apiEndpoint        = 'https://api.ecommercebbva.com/v1';
                 self::$apiSandboxEndpoint = 'https://sand-api.ecommercebbva.com/v1';
             }
-        } elseif ($country == 'CO') {
-            self::$apiEndpoint = 'https://api.openpay.co/v1';
+        }
+        elseif ($country === 'CO')
+        {
+            self::$apiEndpoint        = 'https://api.openpay.co/v1';
             self::$apiSandboxEndpoint = 'https://sandbox-api.openpay.co/v1';
-        } elseif ($country == 'PE') {
-            self::$apiEndpoint = 'https://api.openpay.pe/v1';
+        }
+        elseif ($country === 'PE')
+        {
+            self::$apiEndpoint        = 'https://api.openpay.pe/v1';
             self::$apiSandboxEndpoint = 'https://sandbox-api.openpay.pe/v1';
         }
     }
 
-    public static function getEndpointUrl()
+    public static function getEndpointUrl(): string
     {
-        return (self::getSandboxMode() ? self::$apiSandboxEndpoint : self::$apiEndpoint);
+        return self::getSandboxMode() ? self::$apiSandboxEndpoint : self::$apiEndpoint;
     }
-
 }
diff --git a/Openpay/Data/OpenpayApi.php b/Openpay/Data/OpenpayApi.php
index 4807d78..50bac59 100644
--- a/Openpay/Data/OpenpayApi.php
+++ b/Openpay/Data/OpenpayApi.php
@@ -1,38 +1,49 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Openpay\Data;
 
+use Override;
+
 class OpenpayApi extends OpenpayApiResourceBase
 {
-
-    protected $derivedResources = array(
-        'Bine' => array(),
-        'Customer' => array(),
-        'Card' => array(),
-        'Charge' => array(),
-        'Pse' => array(),
-        'Payout' => array(),
-        'Fee' => array(),
-        'Plan' => array(),
-        'Webhook' => array(),
-        'Token' => array());
-
-    public static function getInstance($r, $p = null)
+    protected $derivedResources = [
+        'Bine'     => [],
+        'Customer' => [],
+        'Card'     => [],
+        'Charge'   => [],
+        'Pse'      => [],
+        'Payout'   => [],
+        'Fee'      => [],
+        'Plan'     => [],
+        'Webhook'  => [],
+        'Token'    => []];
+
+    #[Override]
+    protected static function getInstance($r, $p = null)
     {
-        if(version_compare(phpversion(), '8.3.0', '<')){
-            $resourceName = get_class();
-        } else {
-            $resourceName = self::class;
-        }
+        $resourceName = self::class;
+
         return parent::getInstance($resourceName);
     }
 
-    public function getMerchantInfo()
+    /**
+     * Public entry used by {@see Openpay::getInstance()} (credentials already configured).
+     */
+    public static function createRoot(): self
+    {
+        return self::getInstance(null);
+    }
+
+    #[Override]
+    protected function getMerchantInfo()
     {
         return parent::getMerchantInfo();
     }
 
-    protected function getResourceUrlName($p = true)
+    #[Override]
+    protected function getResourceUrlName($p = true): string
     {
         return '';
     }
@@ -41,5 +52,4 @@ public function getFullURL()
     {
         return $this->getUrl();
     }
-
 }
diff --git a/composer.json b/composer.json
index 320a234..6d621bb 100644
--- a/composer.json
+++ b/composer.json
@@ -1,6 +1,7 @@
 {
     "name": "openpay/sdk",
-    "description": "This is a client implementing the payment services for Openpay at openpay.mx",
+    "description": "This is a client implementing the payment services for Openpay at openpay.mx (Nowo fork: reset/configure for request-safe credentials)",
+    "version": "3.1.1",
     "type": "library",
     "minimum-stability": "dev",
     "license": "Apache-2.0",
@@ -14,18 +15,20 @@
             "name": "Federico Balderas",
             "homepage": "https://openpay.mx/",
             "email": "plugins@openpay.mx"
+        },
+        {
+            "name": "Nowo",
+            "homepage": "https://nowo.tech/"
         }
     ],
     "require": {
-        "php": ">=5.2.1",
+        "php": ">=8.1",
         "ext-curl": "*",
         "ext-hash": "*"
     },
-    "require-dev": {
-        "phpunit/phpunit": "4.8.*"
-    },
     "support": {
-        "issues": "https://github.com/open-pay/openpay-php/issues"
+        "issues": "https://github.com/nowo-tech/openpay-php/issues",
+        "source": "https://github.com/nowo-tech/openpay-php"
     },
     "autoload": {
         "psr-4": {