Add null response handling

README.md

@@ -275,6 +275,14 @@ $customer = ChartMogul\Customer::retrieve($cus->uuid);
 $tags = $customer->addTags("important", "Prio1");
 ```
 
+**Add Tags Using Array (Alternative)**
+
+```php
+$customer = ChartMogul\Customer::retrieve($cus->uuid);
+$tagsArray = ["important", "Prio1", "enterprise"];
+$tags = $customer->addTags($tagsArray);
+```
+
 **Add Tags to Customers with email**
 
 ```php
@@ -292,6 +300,14 @@ $customer = ChartMogul\Customer::retrieve($cus->uuid);
 $tags = $customer->removeTags("important", "Prio1");
 ```
 
+**Remove Tags Using Array (Alternative)**
+
+```php
+$customer = ChartMogul\Customer::retrieve($cus->uuid);
+$tagsToRemove = ["important", "Prio1"];
+$tags = $customer->removeTags($tagsToRemove);
+```
+
 #### Custom Attributes
 
 **Add Custom Attributes to a Customer**
@@ -304,6 +320,23 @@ $custom = $customer->addCustomAttributes(
 );
 ```
 
+**Add Custom Attributes Using Array (Alternative)**
+
+```php
+$customer = ChartMogul\Customer::retrieve($cus->uuid);
+
+// Build attributes array dynamically
+$attributes = [];
+if (!empty($channel)) {
+    $attributes[] = ['type' => 'String', 'key' => 'channel', 'value' => $channel];
+}
+if (!empty($age)) {
+    $attributes[] = ['type' => 'Integer', 'key' => 'age', 'value' => $age];
+}
+
+$custom = $customer->addCustomAttributes($attributes);
+```
+
 
 **Add Custom Attributes to Customers with email**
 
@@ -323,18 +356,40 @@ foreach ($customers->entries as $customer) {
 ```php
 $customer = ChartMogul\Customer::retrieve($cus->uuid);
 $custom = $customer->updateCustomAttributes(
-    ['channel' => 'Twitter'],
-    ['age' => 18]
+    ['type' => 'String', 'key' => 'channel', 'value' => 'Twitter'],
+    ['type' => 'Integer', 'key' => 'age', 'value' => 18]
 );
 ```
 
+**Update Custom Attributes Using Array (Alternative)**
+
+```php
+$customer = ChartMogul\Customer::retrieve($cus->uuid);
+$attributeUpdates = [
+    ['type' => 'String', 'key' => 'channel', 'value' => 'Twitter'],
+    ['type' => 'Integer', 'key' => 'age', 'value' => 18]
+];
+$custom = $customer->updateCustomAttributes($attributeUpdates);
+```
+
 **Remove Custom Attributes from a Customer**
 
 ```php
 $customer = ChartMogul\Customer::retrieve($cus->uuid);
 $tags = $customer->removeCustomAttributes("age", "channel");
 ```
 
+**Remove Custom Attributes Using Array (Alternative)**
+
+```php
+$customer = ChartMogul\Customer::retrieve($cus->uuid);
+$attributesToRemove = [
+    ['key' => 'age'],
+    ['key' => 'channel']
+];
+$tags = $customer->removeCustomAttributes($attributesToRemove);
+```
+
 **List Contacts from a customer**
 
 ```php
@@ -1005,6 +1060,7 @@ The library throws following Exceptions:
 - `ChartMogul\Exceptions\ChartMogulException`
 - `ChartMogul\Exceptions\ConfigurationException`
 - `ChartMogul\Exceptions\ForbiddenException`
+- `ChartMogul\Exceptions\NetworkException`
 - `ChartMogul\Exceptions\NotFoundException`
 - `ChartMogul\Exceptions\ResourceInvalidException`
 - `ChartMogul\Exceptions\SchemaInvalidException`

src/Customer.php

@@ -236,17 +236,32 @@ public static function disconnectSubscriptions($customerUUID, array $data = [],
     /**
      * Add tags to a customer
      *
-     * @param  mixed $tags,...
+     * Supports both individual arguments and array input:
+     * - Individual args: $customer->addTags($tag1, $tag2, ...)
+     * - Array input: $customer->addTags($tagsArray)
+     *
+     * @param  mixed $tags,... Individual tag strings OR array of tags
      * @return array
      */
     public function addTags($tags)
     {
+        $args = func_get_args();
+
+        // Detect if first argument is an array of tags vs individual tag
+        if (count($args) === 1 && is_array($tags)) {
+            // New behavior: Array of tags passed
+            $tagsToSend = $tags;
+        } else {
+            // Existing behavior: Individual arguments (maintain backwards compatibility)
+            $tagsToSend = $args;
+        }
+
         $result = $this->getClient()
             ->send(
                 '/v1/customers/'.$this->uuid.'/attributes/tags',
                 'POST',
                 [
-                'tags' => func_get_args()
+                'tags' => $tagsToSend
                 ]
             );
 
@@ -258,17 +273,32 @@ public function addTags($tags)
     /**
      * Remove Tags from a Customer
      *
-     * @param  mixed $tags,...
+     * Supports both individual arguments and array input:
+     * - Individual args: $customer->removeTags($tag1, $tag2, ...)
+     * - Array input: $customer->removeTags($tagsArray)
+     *
+     * @param  mixed $tags,... Individual tag strings OR array of tags
      * @return array
      */
     public function removeTags($tags)
     {
+        $args = func_get_args();
+
+        // Detect if first argument is an array of tags vs individual tag
+        if (count($args) === 1 && is_array($tags)) {
+            // New behavior: Array of tags passed
+            $tagsToSend = $tags;
+        } else {
+            // Existing behavior: Individual arguments (maintain backwards compatibility)
+            $tagsToSend = $args;
+        }
+
         $result = $this->getClient()
             ->send(
                 '/v1/customers/'.$this->uuid.'/attributes/tags',
                 'DELETE',
                 [
-                'tags' => func_get_args()
+                'tags' => $tagsToSend
                 ]
             );
 
@@ -279,17 +309,33 @@ public function removeTags($tags)
     /**
      * Add Custom Attributes to a Customer
      *
-     * @param  mixed $custom,...
+     * Supports both individual arguments and array input:
+     * - Individual args: $customer->addCustomAttributes($attr1, $attr2, ...)
+     * - Array input: $customer->addCustomAttributes($attributesArray)
+     *
+     * @param  mixed $custom,... Individual attribute objects OR array of attributes
      * @return array
      */
     public function addCustomAttributes($custom)
     {
+        $args = func_get_args();
+
+        // Detect if first argument is an array of attributes vs individual attribute
+        $firstKey = array_key_first($custom);
+        if (count($args) === 1 && is_array($custom) && $firstKey !== null && is_array($custom[$firstKey])) {
+            // New behavior: Array of attribute objects passed
+            $attributesToSend = $custom;
+        } else {
+            // Existing behavior: Individual arguments (maintain backwards compatibility)
+            $attributesToSend = $args;
+        }
+
         $result = $this->getClient()
             ->send(
                 '/v1/customers/'.$this->uuid.'/attributes/custom',
                 'POST',
                 [
-                'custom' => func_get_args()
+                'custom' => $attributesToSend
                 ]
             );
 
@@ -301,17 +347,33 @@ public function addCustomAttributes($custom)
     /**
      * Remove Custom Attributes from a Customer
      *
-     * @param  mixed $custom,...
+     * Supports both individual arguments and array input:
+     * - Individual args: $customer->removeCustomAttributes($attr1, $attr2, ...)
+     * - Array input: $customer->removeCustomAttributes($attributesArray)
+     *
+     * @param  mixed $custom,... Individual attribute objects OR array of attributes
      * @return array
      */
     public function removeCustomAttributes($custom)
     {
+        $args = func_get_args();
+
+        // Detect if first argument is an array of attributes vs individual attribute
+        $firstKey = array_key_first($custom);
+        if (count($args) === 1 && is_array($custom) && $firstKey !== null && is_array($custom[$firstKey])) {
+            // New behavior: Array of attribute objects passed
+            $attributesToSend = $custom;
+        } else {
+            // Existing behavior: Individual arguments (maintain backwards compatibility)
+            $attributesToSend = $args;
+        }
+
         $result = $this->getClient()
             ->send(
                 '/v1/customers/'.$this->uuid.'/attributes/custom',
                 'DELETE',
                 [
-                'custom' => func_get_args()
+                'custom' => $attributesToSend
                 ]
             );
 
@@ -322,15 +384,52 @@ public function removeCustomAttributes($custom)
     /**
      * Update Custom Attributes of a Customer
      *
-     * @param  mixed $custom,...
+     * Supports multiple input formats:
+     * - Individual attribute arrays: $customer->updateCustomAttributes($attr1, $attr2, ...)
+     * - Array of attributes: $customer->updateCustomAttributes($attributesArray)
+     * - Single attribute array: $customer->updateCustomAttributes($singleAttribute)
+     *
+     * @param  mixed $custom,... Individual attribute arrays OR array of attributes
      * @return array
      */
     public function updateCustomAttributes($custom)
     {
-        $data = [];
-        foreach (func_get_args() as $value) {
-            $data = array_merge($data, $value);
+        $args = func_get_args();
+
+        // Handle different input formats
+        if (count($args) === 1) {
+            if (is_array($custom)) {
+                // Check if this is an array of attribute objects vs single attribute object
+                // An array of attributes will have sub-arrays as values
+                $firstKey = array_key_first($custom);
+                $isArrayOfAttributes = $firstKey !== null && is_array($custom[$firstKey]);
+
+                if ($isArrayOfAttributes) {
+                    // Array of attribute objects
+                    $data = [];
+                    foreach ($custom as $attr) {
+                        if (is_array($attr)) {
+                            $data = array_merge($data, $attr);
+                        }
+                    }
+                } else {
+                    // Single attribute object
+                    $data = $custom;
+                }
+            } else {
+                // Single non-array argument (shouldn't happen but handle gracefully)
+                $data = [$custom];
+            }
+        } else {
+            // Multiple arguments - existing behavior
+            $data = [];
+            foreach ($args as $value) {
+                if (is_array($value)) {
+                    $data = array_merge($data, $value);
+                }
+            }
         }
+
         $result = $this->getClient()
             ->send(
                 '/v1/customers/'.$this->uuid.'/attributes/custom',

src/Exceptions/NetworkException.php

@@ -0,0 +1,23 @@
+<?php
+
+namespace ChartMogul\Exceptions;
+
+/**
+ * Network-related exceptions for ChartMogul API requests.
+ *
+ * Thrown when network requests fail, timeout, or return null responses.
+ */
+class NetworkException extends ChartMogulException
+{
+    /**
+     * NetworkException constructor.
+     *
+     * @param string $message Error message describing the network failure
+     * @param \Psr\Http\Message\ResponseInterface|null $response HTTP response if available
+     * @param \Throwable|null $previous Previous exception for chaining
+     */
+    public function __construct(string $message, ?\Psr\Http\Message\ResponseInterface $response = null, ?\Throwable $previous = null)
+    {
+        parent::__construct($message, $response, $previous);
+    }
+}

src/Http/Client.php

@@ -158,6 +158,7 @@ function () use ($request) {
                 return $this->client->sendRequest($request);
             }
         );
+
         return $this->handleResponse($response);
     }
 

src/Http/Retry.php

@@ -42,11 +42,28 @@ protected function shouldRetry($attempt, $maxAttempts, ?ResponseInterface $respo
     public function retry($callback)
     {
         if ($this->retries === 0) {
-            return $callback();
+            $result = $callback();
+            // Ensure we never return null for HTTP responses
+            if ($result === null) {
+                throw new \ChartMogul\Exceptions\NetworkException(
+                    'Request failed with no response'
+                );
+            }
+            return $result;
         }
+
         $backoff = new Backoff($this->retries, new ExponentialStrategy(), 60 * 1000, true);
         $backoff->setDecider($this);
-        return $backoff->run($callback);
+        $result = $backoff->run($callback);
+
+        // Validate result is not null after all retries
+        if ($result === null) {
+            throw new \ChartMogul\Exceptions\NetworkException(
+                'All retry attempts failed with no response'
+            );
+        }
+
+        return $result;
     }
 
     public function __invoke($attempt, $maxAttempts, $response, $exception)