diff --git a/composer.json b/composer.json
index ef662ae..f764db6 100644
--- a/composer.json
+++ b/composer.json
@@ -1,6 +1,6 @@
 {
     "name": "mailchimp/marketing",
-    "version": "3.0.80",
+    "version": "3.0.81",
     "description": "",
     "keywords": [
         "swagger",
@@ -17,7 +17,7 @@
         }
     ],
     "require": {
-        "php": ">=7.2",
+        "php": ">=8.1",
         "ext-curl": "*",
         "ext-json": "*",
         "ext-mbstring": "*",
@@ -25,7 +25,7 @@
         "guzzlehttp/guzzle": "^6.4 || ^7.2"
     },
     "require-dev": {
-        "phpunit/phpunit": "^7",
+        "phpunit/phpunit": "^8",
         "squizlabs/php_codesniffer": "~2.6",
         "friendsofphp/php-cs-fixer": "~2.12"
     },
diff --git a/lib/Api/AccountExportApi.php b/lib/Api/AccountExportApi.php
index 2e85f3c..db70145 100644
--- a/lib/Api/AccountExportApi.php
+++ b/lib/Api/AccountExportApi.php
@@ -29,40 +29,16 @@
 
 namespace MailchimpMarketing\Api;
 
-use GuzzleHttp\Client;
-use GuzzleHttp\ClientInterface;
 use GuzzleHttp\Exception\RequestException;
 use GuzzleHttp\Psr7\MultipartStream;
 use GuzzleHttp\Psr7\Query;
 use GuzzleHttp\Psr7\Request;
 use GuzzleHttp\RequestOptions;
 use MailchimpMarketing\ApiException;
-use MailchimpMarketing\Configuration;
-use MailchimpMarketing\HeaderSelector;
 use MailchimpMarketing\ObjectSerializer;
 
-class AccountExportApi
+class AccountExportApi extends BaseApi
 {
-    protected $client;
-    protected $config;
-    protected $headerSelector;
-
-    public function __construct(Configuration $config = null)
-    {
-        $this->client = new Client([
-            'defaults' => [
-                'timeout' => 120.0
-            ]
-        ]);
-        $this->headerSelector = new HeaderSelector();
-        $this->config = $config ?: new Configuration();
-    }
-
-    public function getConfig()
-    {
-        return $this->config;
-    }
-
     public function getAccountExports($export_id, $fields = null, $exclude_fields = null)
     {
         $response = $this->getAccountExportsWithHttpInfo($export_id, $fields, $exclude_fields);
diff --git a/lib/Api/AccountExportsApi.php b/lib/Api/AccountExportsApi.php
index 954cbd6..102e2e3 100644
--- a/lib/Api/AccountExportsApi.php
+++ b/lib/Api/AccountExportsApi.php
@@ -29,40 +29,16 @@
 
 namespace MailchimpMarketing\Api;
 
-use GuzzleHttp\Client;
-use GuzzleHttp\ClientInterface;
 use GuzzleHttp\Exception\RequestException;
 use GuzzleHttp\Psr7\MultipartStream;
 use GuzzleHttp\Psr7\Query;
 use GuzzleHttp\Psr7\Request;
 use GuzzleHttp\RequestOptions;
 use MailchimpMarketing\ApiException;
-use MailchimpMarketing\Configuration;
-use MailchimpMarketing\HeaderSelector;
 use MailchimpMarketing\ObjectSerializer;
 
-class AccountExportsApi
+class AccountExportsApi extends BaseApi
 {
-    protected $client;
-    protected $config;
-    protected $headerSelector;
-
-    public function __construct(Configuration $config = null)
-    {
-        $this->client = new Client([
-            'defaults' => [
-                'timeout' => 120.0
-            ]
-        ]);
-        $this->headerSelector = new HeaderSelector();
-        $this->config = $config ?: new Configuration();
-    }
-
-    public function getConfig()
-    {
-        return $this->config;
-    }
-
     public function listAccountExports($fields = null, $exclude_fields = null, $count = '10', $offset = '0')
     {
         $response = $this->listAccountExportsWithHttpInfo($fields, $exclude_fields, $count, $offset);
diff --git a/lib/Api/ActivityFeedApi.php b/lib/Api/ActivityFeedApi.php
index 7d5de50..973de76 100644
--- a/lib/Api/ActivityFeedApi.php
+++ b/lib/Api/ActivityFeedApi.php
@@ -29,40 +29,16 @@
 
 namespace MailchimpMarketing\Api;
 
-use GuzzleHttp\Client;
-use GuzzleHttp\ClientInterface;
 use GuzzleHttp\Exception\RequestException;
 use GuzzleHttp\Psr7\MultipartStream;
 use GuzzleHttp\Psr7\Query;
 use GuzzleHttp\Psr7\Request;
 use GuzzleHttp\RequestOptions;
 use MailchimpMarketing\ApiException;
-use MailchimpMarketing\Configuration;
-use MailchimpMarketing\HeaderSelector;
 use MailchimpMarketing\ObjectSerializer;
 
-class ActivityFeedApi
+class ActivityFeedApi extends BaseApi
 {
-    protected $client;
-    protected $config;
-    protected $headerSelector;
-
-    public function __construct(Configuration $config = null)
-    {
-        $this->client = new Client([
-            'defaults' => [
-                'timeout' => 120.0
-            ]
-        ]);
-        $this->headerSelector = new HeaderSelector();
-        $this->config = $config ?: new Configuration();
-    }
-
-    public function getConfig()
-    {
-        return $this->config;
-    }
-
     public function getChimpChatter($count = '10', $offset = '0')
     {
         $response = $this->getChimpChatterWithHttpInfo($count, $offset);
diff --git a/lib/Api/AuthorizedAppsApi.php b/lib/Api/AuthorizedAppsApi.php
index 24cd726..6ed8774 100644
--- a/lib/Api/AuthorizedAppsApi.php
+++ b/lib/Api/AuthorizedAppsApi.php
@@ -29,40 +29,16 @@
 
 namespace MailchimpMarketing\Api;
 
-use GuzzleHttp\Client;
-use GuzzleHttp\ClientInterface;
 use GuzzleHttp\Exception\RequestException;
 use GuzzleHttp\Psr7\MultipartStream;
 use GuzzleHttp\Psr7\Query;
 use GuzzleHttp\Psr7\Request;
 use GuzzleHttp\RequestOptions;
 use MailchimpMarketing\ApiException;
-use MailchimpMarketing\Configuration;
-use MailchimpMarketing\HeaderSelector;
 use MailchimpMarketing\ObjectSerializer;
 
-class AuthorizedAppsApi
+class AuthorizedAppsApi extends BaseApi
 {
-    protected $client;
-    protected $config;
-    protected $headerSelector;
-
-    public function __construct(Configuration $config = null)
-    {
-        $this->client = new Client([
-            'defaults' => [
-                'timeout' => 120.0
-            ]
-        ]);
-        $this->headerSelector = new HeaderSelector();
-        $this->config = $config ?: new Configuration();
-    }
-
-    public function getConfig()
-    {
-        return $this->config;
-    }
-
     public function list($fields = null, $exclude_fields = null, $count = '10', $offset = '0')
     {
         $response = $this->listWithHttpInfo($fields, $exclude_fields, $count, $offset);
diff --git a/lib/Api/AutomationsApi.php b/lib/Api/AutomationsApi.php
index e7fc5a1..ae91b5c 100644
--- a/lib/Api/AutomationsApi.php
+++ b/lib/Api/AutomationsApi.php
@@ -29,40 +29,16 @@
 
 namespace MailchimpMarketing\Api;
 
-use GuzzleHttp\Client;
-use GuzzleHttp\ClientInterface;
 use GuzzleHttp\Exception\RequestException;
 use GuzzleHttp\Psr7\MultipartStream;
 use GuzzleHttp\Psr7\Query;
 use GuzzleHttp\Psr7\Request;
 use GuzzleHttp\RequestOptions;
 use MailchimpMarketing\ApiException;
-use MailchimpMarketing\Configuration;
-use MailchimpMarketing\HeaderSelector;
 use MailchimpMarketing\ObjectSerializer;
 
-class AutomationsApi
+class AutomationsApi extends BaseApi
 {
-    protected $client;
-    protected $config;
-    protected $headerSelector;
-
-    public function __construct(Configuration $config = null)
-    {
-        $this->client = new Client([
-            'defaults' => [
-                'timeout' => 120.0
-            ]
-        ]);
-        $this->headerSelector = new HeaderSelector();
-        $this->config = $config ?: new Configuration();
-    }
-
-    public function getConfig()
-    {
-        return $this->config;
-    }
-
     public function archive($workflow_id)
     {
         $this->archiveWithHttpInfo($workflow_id);
diff --git a/lib/Api/BaseApi.php b/lib/Api/BaseApi.php
new file mode 100644
index 0000000..1731efd
--- /dev/null
+++ b/lib/Api/BaseApi.php
@@ -0,0 +1,29 @@
+<?php
+namespace MailchimpMarketing\Api;
+
+use GuzzleHttp\Client;
+use MailchimpMarketing\Configuration;
+use MailchimpMarketing\HeaderSelector;
+
+class BaseApi
+{
+    protected Client $client;
+    protected Configuration $config;
+    protected HeaderSelector $headerSelector;
+
+    public function __construct(?Configuration $config = null)
+    {
+        $this->client = new Client([
+            'defaults' => [
+                'timeout' => 120.0
+            ]
+        ]);
+        $this->headerSelector = new HeaderSelector();
+        $this->config = $config ?: new Configuration();
+    }
+
+    public function getConfig(): Configuration
+    {
+        return $this->config;
+    }
+}
diff --git a/lib/Api/BatchWebhooksApi.php b/lib/Api/BatchWebhooksApi.php
index d894ada..4637260 100644
--- a/lib/Api/BatchWebhooksApi.php
+++ b/lib/Api/BatchWebhooksApi.php
@@ -29,40 +29,16 @@
 
 namespace MailchimpMarketing\Api;
 
-use GuzzleHttp\Client;
-use GuzzleHttp\ClientInterface;
 use GuzzleHttp\Exception\RequestException;
 use GuzzleHttp\Psr7\MultipartStream;
 use GuzzleHttp\Psr7\Query;
 use GuzzleHttp\Psr7\Request;
 use GuzzleHttp\RequestOptions;
 use MailchimpMarketing\ApiException;
-use MailchimpMarketing\Configuration;
-use MailchimpMarketing\HeaderSelector;
 use MailchimpMarketing\ObjectSerializer;
 
-class BatchWebhooksApi
+class BatchWebhooksApi extends BaseApi
 {
-    protected $client;
-    protected $config;
-    protected $headerSelector;
-
-    public function __construct(Configuration $config = null)
-    {
-        $this->client = new Client([
-            'defaults' => [
-                'timeout' => 120.0
-            ]
-        ]);
-        $this->headerSelector = new HeaderSelector();
-        $this->config = $config ?: new Configuration();
-    }
-
-    public function getConfig()
-    {
-        return $this->config;
-    }
-
     public function remove($batch_webhook_id)
     {
         $this->removeWithHttpInfo($batch_webhook_id);
diff --git a/lib/Api/BatchesApi.php b/lib/Api/BatchesApi.php
index 7af379e..c239224 100644
--- a/lib/Api/BatchesApi.php
+++ b/lib/Api/BatchesApi.php
@@ -29,40 +29,16 @@
 
 namespace MailchimpMarketing\Api;
 
-use GuzzleHttp\Client;
-use GuzzleHttp\ClientInterface;
 use GuzzleHttp\Exception\RequestException;
 use GuzzleHttp\Psr7\MultipartStream;
 use GuzzleHttp\Psr7\Query;
 use GuzzleHttp\Psr7\Request;
 use GuzzleHttp\RequestOptions;
 use MailchimpMarketing\ApiException;
-use MailchimpMarketing\Configuration;
-use MailchimpMarketing\HeaderSelector;
 use MailchimpMarketing\ObjectSerializer;
 
-class BatchesApi
+class BatchesApi extends BaseApi
 {
-    protected $client;
-    protected $config;
-    protected $headerSelector;
-
-    public function __construct(Configuration $config = null)
-    {
-        $this->client = new Client([
-            'defaults' => [
-                'timeout' => 120.0
-            ]
-        ]);
-        $this->headerSelector = new HeaderSelector();
-        $this->config = $config ?: new Configuration();
-    }
-
-    public function getConfig()
-    {
-        return $this->config;
-    }
-
     public function deleteRequest($batch_id)
     {
         $this->deleteRequestWithHttpInfo($batch_id);
diff --git a/lib/Api/CampaignFoldersApi.php b/lib/Api/CampaignFoldersApi.php
index 175fa7d..998b7da 100644
--- a/lib/Api/CampaignFoldersApi.php
+++ b/lib/Api/CampaignFoldersApi.php
@@ -29,40 +29,16 @@
 
 namespace MailchimpMarketing\Api;
 
-use GuzzleHttp\Client;
-use GuzzleHttp\ClientInterface;
 use GuzzleHttp\Exception\RequestException;
 use GuzzleHttp\Psr7\MultipartStream;
 use GuzzleHttp\Psr7\Query;
 use GuzzleHttp\Psr7\Request;
 use GuzzleHttp\RequestOptions;
 use MailchimpMarketing\ApiException;
-use MailchimpMarketing\Configuration;
-use MailchimpMarketing\HeaderSelector;
 use MailchimpMarketing\ObjectSerializer;
 
-class CampaignFoldersApi
+class CampaignFoldersApi extends BaseApi
 {
-    protected $client;
-    protected $config;
-    protected $headerSelector;
-
-    public function __construct(Configuration $config = null)
-    {
-        $this->client = new Client([
-            'defaults' => [
-                'timeout' => 120.0
-            ]
-        ]);
-        $this->headerSelector = new HeaderSelector();
-        $this->config = $config ?: new Configuration();
-    }
-
-    public function getConfig()
-    {
-        return $this->config;
-    }
-
     public function remove($folder_id)
     {
         $this->removeWithHttpInfo($folder_id);
diff --git a/lib/Api/CampaignsApi.php b/lib/Api/CampaignsApi.php
index c28a249..2eab3ab 100644
--- a/lib/Api/CampaignsApi.php
+++ b/lib/Api/CampaignsApi.php
@@ -29,40 +29,16 @@
 
 namespace MailchimpMarketing\Api;
 
-use GuzzleHttp\Client;
-use GuzzleHttp\ClientInterface;
 use GuzzleHttp\Exception\RequestException;
 use GuzzleHttp\Psr7\MultipartStream;
 use GuzzleHttp\Psr7\Query;
 use GuzzleHttp\Psr7\Request;
 use GuzzleHttp\RequestOptions;
 use MailchimpMarketing\ApiException;
-use MailchimpMarketing\Configuration;
-use MailchimpMarketing\HeaderSelector;
 use MailchimpMarketing\ObjectSerializer;
 
-class CampaignsApi
+class CampaignsApi extends BaseApi
 {
-    protected $client;
-    protected $config;
-    protected $headerSelector;
-
-    public function __construct(Configuration $config = null)
-    {
-        $this->client = new Client([
-            'defaults' => [
-                'timeout' => 120.0
-            ]
-        ]);
-        $this->headerSelector = new HeaderSelector();
-        $this->config = $config ?: new Configuration();
-    }
-
-    public function getConfig()
-    {
-        return $this->config;
-    }
-
     public function remove($campaign_id)
     {
         $this->removeWithHttpInfo($campaign_id);
diff --git a/lib/Api/ConnectedSitesApi.php b/lib/Api/ConnectedSitesApi.php
index 01d7726..96fb078 100644
--- a/lib/Api/ConnectedSitesApi.php
+++ b/lib/Api/ConnectedSitesApi.php
@@ -29,40 +29,16 @@
 
 namespace MailchimpMarketing\Api;
 
-use GuzzleHttp\Client;
-use GuzzleHttp\ClientInterface;
 use GuzzleHttp\Exception\RequestException;
 use GuzzleHttp\Psr7\MultipartStream;
 use GuzzleHttp\Psr7\Query;
 use GuzzleHttp\Psr7\Request;
 use GuzzleHttp\RequestOptions;
 use MailchimpMarketing\ApiException;
-use MailchimpMarketing\Configuration;
-use MailchimpMarketing\HeaderSelector;
 use MailchimpMarketing\ObjectSerializer;
 
-class ConnectedSitesApi
+class ConnectedSitesApi extends BaseApi
 {
-    protected $client;
-    protected $config;
-    protected $headerSelector;
-
-    public function __construct(Configuration $config = null)
-    {
-        $this->client = new Client([
-            'defaults' => [
-                'timeout' => 120.0
-            ]
-        ]);
-        $this->headerSelector = new HeaderSelector();
-        $this->config = $config ?: new Configuration();
-    }
-
-    public function getConfig()
-    {
-        return $this->config;
-    }
-
     public function remove($connected_site_id)
     {
         $this->removeWithHttpInfo($connected_site_id);
diff --git a/lib/Api/ConversationsApi.php b/lib/Api/ConversationsApi.php
index 2d359fd..c64d7cf 100644
--- a/lib/Api/ConversationsApi.php
+++ b/lib/Api/ConversationsApi.php
@@ -29,40 +29,16 @@
 
 namespace MailchimpMarketing\Api;
 
-use GuzzleHttp\Client;
-use GuzzleHttp\ClientInterface;
 use GuzzleHttp\Exception\RequestException;
 use GuzzleHttp\Psr7\MultipartStream;
 use GuzzleHttp\Psr7\Query;
 use GuzzleHttp\Psr7\Request;
 use GuzzleHttp\RequestOptions;
 use MailchimpMarketing\ApiException;
-use MailchimpMarketing\Configuration;
-use MailchimpMarketing\HeaderSelector;
 use MailchimpMarketing\ObjectSerializer;
 
-class ConversationsApi
+class ConversationsApi extends BaseApi
 {
-    protected $client;
-    protected $config;
-    protected $headerSelector;
-
-    public function __construct(Configuration $config = null)
-    {
-        $this->client = new Client([
-            'defaults' => [
-                'timeout' => 120.0
-            ]
-        ]);
-        $this->headerSelector = new HeaderSelector();
-        $this->config = $config ?: new Configuration();
-    }
-
-    public function getConfig()
-    {
-        return $this->config;
-    }
-
     public function list($fields = null, $exclude_fields = null, $count = '10', $offset = '0', $has_unread_messages = null, $list_id = null, $campaign_id = null)
     {
         $response = $this->listWithHttpInfo($fields, $exclude_fields, $count, $offset, $has_unread_messages, $list_id, $campaign_id);
diff --git a/lib/Api/CustomerJourneysApi.php b/lib/Api/CustomerJourneysApi.php
index adea5b5..6d38d1b 100644
--- a/lib/Api/CustomerJourneysApi.php
+++ b/lib/Api/CustomerJourneysApi.php
@@ -29,40 +29,16 @@
 
 namespace MailchimpMarketing\Api;
 
-use GuzzleHttp\Client;
-use GuzzleHttp\ClientInterface;
 use GuzzleHttp\Exception\RequestException;
 use GuzzleHttp\Psr7\MultipartStream;
 use GuzzleHttp\Psr7\Query;
 use GuzzleHttp\Psr7\Request;
 use GuzzleHttp\RequestOptions;
 use MailchimpMarketing\ApiException;
-use MailchimpMarketing\Configuration;
-use MailchimpMarketing\HeaderSelector;
 use MailchimpMarketing\ObjectSerializer;
 
-class CustomerJourneysApi
+class CustomerJourneysApi extends BaseApi
 {
-    protected $client;
-    protected $config;
-    protected $headerSelector;
-
-    public function __construct(Configuration $config = null)
-    {
-        $this->client = new Client([
-            'defaults' => [
-                'timeout' => 120.0
-            ]
-        ]);
-        $this->headerSelector = new HeaderSelector();
-        $this->config = $config ?: new Configuration();
-    }
-
-    public function getConfig()
-    {
-        return $this->config;
-    }
-
     public function trigger($journey_id, $step_id, $body)
     {
         $response = $this->triggerWithHttpInfo($journey_id, $step_id, $body);
diff --git a/lib/Api/EcommerceApi.php b/lib/Api/EcommerceApi.php
index a39b782..7d4a37c 100644
--- a/lib/Api/EcommerceApi.php
+++ b/lib/Api/EcommerceApi.php
@@ -29,40 +29,16 @@
 
 namespace MailchimpMarketing\Api;
 
-use GuzzleHttp\Client;
-use GuzzleHttp\ClientInterface;
 use GuzzleHttp\Exception\RequestException;
 use GuzzleHttp\Psr7\MultipartStream;
 use GuzzleHttp\Psr7\Query;
 use GuzzleHttp\Psr7\Request;
 use GuzzleHttp\RequestOptions;
 use MailchimpMarketing\ApiException;
-use MailchimpMarketing\Configuration;
-use MailchimpMarketing\HeaderSelector;
 use MailchimpMarketing\ObjectSerializer;
 
-class EcommerceApi
+class EcommerceApi extends BaseApi
 {
-    protected $client;
-    protected $config;
-    protected $headerSelector;
-
-    public function __construct(Configuration $config = null)
-    {
-        $this->client = new Client([
-            'defaults' => [
-                'timeout' => 120.0
-            ]
-        ]);
-        $this->headerSelector = new HeaderSelector();
-        $this->config = $config ?: new Configuration();
-    }
-
-    public function getConfig()
-    {
-        return $this->config;
-    }
-
     public function deleteStore($store_id)
     {
         $response = $this->deleteStoreWithHttpInfo($store_id);
diff --git a/lib/Api/FacebookAdsApi.php b/lib/Api/FacebookAdsApi.php
index f7f63a2..7091945 100644
--- a/lib/Api/FacebookAdsApi.php
+++ b/lib/Api/FacebookAdsApi.php
@@ -41,28 +41,8 @@
 use MailchimpMarketing\HeaderSelector;
 use MailchimpMarketing\ObjectSerializer;
 
-class FacebookAdsApi
+class FacebookAdsApi extends BaseApi
 {
-    protected $client;
-    protected $config;
-    protected $headerSelector;
-
-    public function __construct(Configuration $config = null)
-    {
-        $this->client = new Client([
-            'defaults' => [
-                'timeout' => 120.0
-            ]
-        ]);
-        $this->headerSelector = new HeaderSelector();
-        $this->config = $config ?: new Configuration();
-    }
-
-    public function getConfig()
-    {
-        return $this->config;
-    }
-
     public function list($fields = null, $exclude_fields = null, $count = '10', $offset = '0', $sort_field = null, $sort_dir = null)
     {
         $response = $this->listWithHttpInfo($fields, $exclude_fields, $count, $offset, $sort_field, $sort_dir);
diff --git a/lib/Api/FileManagerApi.php b/lib/Api/FileManagerApi.php
index e0eb4c4..92049d6 100644
--- a/lib/Api/FileManagerApi.php
+++ b/lib/Api/FileManagerApi.php
@@ -29,40 +29,16 @@
 
 namespace MailchimpMarketing\Api;
 
-use GuzzleHttp\Client;
-use GuzzleHttp\ClientInterface;
 use GuzzleHttp\Exception\RequestException;
 use GuzzleHttp\Psr7\MultipartStream;
 use GuzzleHttp\Psr7\Query;
 use GuzzleHttp\Psr7\Request;
 use GuzzleHttp\RequestOptions;
 use MailchimpMarketing\ApiException;
-use MailchimpMarketing\Configuration;
-use MailchimpMarketing\HeaderSelector;
 use MailchimpMarketing\ObjectSerializer;
 
-class FileManagerApi
+class FileManagerApi extends BaseApi
 {
-    protected $client;
-    protected $config;
-    protected $headerSelector;
-
-    public function __construct(Configuration $config = null)
-    {
-        $this->client = new Client([
-            'defaults' => [
-                'timeout' => 120.0
-            ]
-        ]);
-        $this->headerSelector = new HeaderSelector();
-        $this->config = $config ?: new Configuration();
-    }
-
-    public function getConfig()
-    {
-        return $this->config;
-    }
-
     public function deleteFile($file_id)
     {
         $this->deleteFileWithHttpInfo($file_id);
diff --git a/lib/Api/LandingPagesApi.php b/lib/Api/LandingPagesApi.php
index bba6e36..e59ca91 100644
--- a/lib/Api/LandingPagesApi.php
+++ b/lib/Api/LandingPagesApi.php
@@ -29,40 +29,16 @@
 
 namespace MailchimpMarketing\Api;
 
-use GuzzleHttp\Client;
-use GuzzleHttp\ClientInterface;
 use GuzzleHttp\Exception\RequestException;
 use GuzzleHttp\Psr7\MultipartStream;
 use GuzzleHttp\Psr7\Query;
 use GuzzleHttp\Psr7\Request;
 use GuzzleHttp\RequestOptions;
 use MailchimpMarketing\ApiException;
-use MailchimpMarketing\Configuration;
-use MailchimpMarketing\HeaderSelector;
 use MailchimpMarketing\ObjectSerializer;
 
-class LandingPagesApi
+class LandingPagesApi extends BaseApi
 {
-    protected $client;
-    protected $config;
-    protected $headerSelector;
-
-    public function __construct(Configuration $config = null)
-    {
-        $this->client = new Client([
-            'defaults' => [
-                'timeout' => 120.0
-            ]
-        ]);
-        $this->headerSelector = new HeaderSelector();
-        $this->config = $config ?: new Configuration();
-    }
-
-    public function getConfig()
-    {
-        return $this->config;
-    }
-
     public function deletePage($page_id)
     {
         $this->deletePageWithHttpInfo($page_id);
diff --git a/lib/Api/ListsApi.php b/lib/Api/ListsApi.php
index 2abd6ad..1410ba5 100644
--- a/lib/Api/ListsApi.php
+++ b/lib/Api/ListsApi.php
@@ -29,40 +29,16 @@
 
 namespace MailchimpMarketing\Api;
 
-use GuzzleHttp\Client;
-use GuzzleHttp\ClientInterface;
 use GuzzleHttp\Exception\RequestException;
 use GuzzleHttp\Psr7\MultipartStream;
 use GuzzleHttp\Psr7\Query;
 use GuzzleHttp\Psr7\Request;
 use GuzzleHttp\RequestOptions;
 use MailchimpMarketing\ApiException;
-use MailchimpMarketing\Configuration;
-use MailchimpMarketing\HeaderSelector;
 use MailchimpMarketing\ObjectSerializer;
 
-class ListsApi
+class ListsApi extends BaseApi
 {
-    protected $client;
-    protected $config;
-    protected $headerSelector;
-
-    public function __construct(Configuration $config = null)
-    {
-        $this->client = new Client([
-            'defaults' => [
-                'timeout' => 120.0
-            ]
-        ]);
-        $this->headerSelector = new HeaderSelector();
-        $this->config = $config ?: new Configuration();
-    }
-
-    public function getConfig()
-    {
-        return $this->config;
-    }
-
     public function deleteList($list_id)
     {
         $this->deleteListWithHttpInfo($list_id);
diff --git a/lib/Api/PingApi.php b/lib/Api/PingApi.php
index 2dacbec..e9d83f7 100644
--- a/lib/Api/PingApi.php
+++ b/lib/Api/PingApi.php
@@ -29,40 +29,16 @@
 
 namespace MailchimpMarketing\Api;
 
-use GuzzleHttp\Client;
-use GuzzleHttp\ClientInterface;
 use GuzzleHttp\Exception\RequestException;
 use GuzzleHttp\Psr7\MultipartStream;
 use GuzzleHttp\Psr7\Query;
 use GuzzleHttp\Psr7\Request;
 use GuzzleHttp\RequestOptions;
 use MailchimpMarketing\ApiException;
-use MailchimpMarketing\Configuration;
-use MailchimpMarketing\HeaderSelector;
 use MailchimpMarketing\ObjectSerializer;
 
-class PingApi
+class PingApi extends BaseApi
 {
-    protected $client;
-    protected $config;
-    protected $headerSelector;
-
-    public function __construct(Configuration $config = null)
-    {
-        $this->client = new Client([
-            'defaults' => [
-                'timeout' => 120.0
-            ]
-        ]);
-        $this->headerSelector = new HeaderSelector();
-        $this->config = $config ?: new Configuration();
-    }
-
-    public function getConfig()
-    {
-        return $this->config;
-    }
-
     public function get()
     {
         $response = $this->getWithHttpInfo();
diff --git a/lib/Api/ReportingApi.php b/lib/Api/ReportingApi.php
index 74dd26c..ef19534 100644
--- a/lib/Api/ReportingApi.php
+++ b/lib/Api/ReportingApi.php
@@ -29,40 +29,16 @@
 
 namespace MailchimpMarketing\Api;
 
-use GuzzleHttp\Client;
-use GuzzleHttp\ClientInterface;
 use GuzzleHttp\Exception\RequestException;
 use GuzzleHttp\Psr7\MultipartStream;
 use GuzzleHttp\Psr7\Query;
 use GuzzleHttp\Psr7\Request;
 use GuzzleHttp\RequestOptions;
 use MailchimpMarketing\ApiException;
-use MailchimpMarketing\Configuration;
-use MailchimpMarketing\HeaderSelector;
 use MailchimpMarketing\ObjectSerializer;
 
-class ReportingApi
+class ReportingApi extends BaseApi
 {
-    protected $client;
-    protected $config;
-    protected $headerSelector;
-
-    public function __construct(Configuration $config = null)
-    {
-        $this->client = new Client([
-            'defaults' => [
-                'timeout' => 120.0
-            ]
-        ]);
-        $this->headerSelector = new HeaderSelector();
-        $this->config = $config ?: new Configuration();
-    }
-
-    public function getConfig()
-    {
-        return $this->config;
-    }
-
     public function getFacebookAdsReportAll($fields = null, $exclude_fields = null, $count = '10', $offset = '0', $sort_field = null, $sort_dir = null)
     {
         $response = $this->getFacebookAdsReportAllWithHttpInfo($fields, $exclude_fields, $count, $offset, $sort_field, $sort_dir);
diff --git a/lib/Api/ReportsApi.php b/lib/Api/ReportsApi.php
index 92b4ea3..7b98c7c 100644
--- a/lib/Api/ReportsApi.php
+++ b/lib/Api/ReportsApi.php
@@ -29,40 +29,16 @@
 
 namespace MailchimpMarketing\Api;
 
-use GuzzleHttp\Client;
-use GuzzleHttp\ClientInterface;
 use GuzzleHttp\Exception\RequestException;
 use GuzzleHttp\Psr7\MultipartStream;
 use GuzzleHttp\Psr7\Query;
 use GuzzleHttp\Psr7\Request;
 use GuzzleHttp\RequestOptions;
 use MailchimpMarketing\ApiException;
-use MailchimpMarketing\Configuration;
-use MailchimpMarketing\HeaderSelector;
 use MailchimpMarketing\ObjectSerializer;
 
-class ReportsApi
+class ReportsApi extends BaseApi
 {
-    protected $client;
-    protected $config;
-    protected $headerSelector;
-
-    public function __construct(Configuration $config = null)
-    {
-        $this->client = new Client([
-            'defaults' => [
-                'timeout' => 120.0
-            ]
-        ]);
-        $this->headerSelector = new HeaderSelector();
-        $this->config = $config ?: new Configuration();
-    }
-
-    public function getConfig()
-    {
-        return $this->config;
-    }
-
     public function getAllCampaignReports($fields = null, $exclude_fields = null, $count = '10', $offset = '0', $type = null, $before_send_time = null, $since_send_time = null)
     {
         $response = $this->getAllCampaignReportsWithHttpInfo($fields, $exclude_fields, $count, $offset, $type, $before_send_time, $since_send_time);
diff --git a/lib/Api/RootApi.php b/lib/Api/RootApi.php
index ea659b2..dcdadab 100644
--- a/lib/Api/RootApi.php
+++ b/lib/Api/RootApi.php
@@ -29,40 +29,16 @@
 
 namespace MailchimpMarketing\Api;
 
-use GuzzleHttp\Client;
-use GuzzleHttp\ClientInterface;
 use GuzzleHttp\Exception\RequestException;
 use GuzzleHttp\Psr7\MultipartStream;
 use GuzzleHttp\Psr7\Query;
 use GuzzleHttp\Psr7\Request;
 use GuzzleHttp\RequestOptions;
 use MailchimpMarketing\ApiException;
-use MailchimpMarketing\Configuration;
-use MailchimpMarketing\HeaderSelector;
 use MailchimpMarketing\ObjectSerializer;
 
-class RootApi
+class RootApi extends BaseApi
 {
-    protected $client;
-    protected $config;
-    protected $headerSelector;
-
-    public function __construct(Configuration $config = null)
-    {
-        $this->client = new Client([
-            'defaults' => [
-                'timeout' => 120.0
-            ]
-        ]);
-        $this->headerSelector = new HeaderSelector();
-        $this->config = $config ?: new Configuration();
-    }
-
-    public function getConfig()
-    {
-        return $this->config;
-    }
-
     public function getRoot($fields = null, $exclude_fields = null)
     {
         $response = $this->getRootWithHttpInfo($fields, $exclude_fields);
diff --git a/lib/Api/SearchCampaignsApi.php b/lib/Api/SearchCampaignsApi.php
index 908ff39..e7802a4 100644
--- a/lib/Api/SearchCampaignsApi.php
+++ b/lib/Api/SearchCampaignsApi.php
@@ -29,40 +29,16 @@
 
 namespace MailchimpMarketing\Api;
 
-use GuzzleHttp\Client;
-use GuzzleHttp\ClientInterface;
 use GuzzleHttp\Exception\RequestException;
 use GuzzleHttp\Psr7\MultipartStream;
 use GuzzleHttp\Psr7\Query;
 use GuzzleHttp\Psr7\Request;
 use GuzzleHttp\RequestOptions;
 use MailchimpMarketing\ApiException;
-use MailchimpMarketing\Configuration;
-use MailchimpMarketing\HeaderSelector;
 use MailchimpMarketing\ObjectSerializer;
 
-class SearchCampaignsApi
+class SearchCampaignsApi extends BaseApi
 {
-    protected $client;
-    protected $config;
-    protected $headerSelector;
-
-    public function __construct(Configuration $config = null)
-    {
-        $this->client = new Client([
-            'defaults' => [
-                'timeout' => 120.0
-            ]
-        ]);
-        $this->headerSelector = new HeaderSelector();
-        $this->config = $config ?: new Configuration();
-    }
-
-    public function getConfig()
-    {
-        return $this->config;
-    }
-
     public function search($query, $fields = null, $exclude_fields = null)
     {
         $response = $this->searchWithHttpInfo($query, $fields, $exclude_fields);
diff --git a/lib/Api/SearchMembersApi.php b/lib/Api/SearchMembersApi.php
index ea58e78..b8c00cc 100644
--- a/lib/Api/SearchMembersApi.php
+++ b/lib/Api/SearchMembersApi.php
@@ -29,40 +29,16 @@
 
 namespace MailchimpMarketing\Api;
 
-use GuzzleHttp\Client;
-use GuzzleHttp\ClientInterface;
 use GuzzleHttp\Exception\RequestException;
 use GuzzleHttp\Psr7\MultipartStream;
 use GuzzleHttp\Psr7\Query;
 use GuzzleHttp\Psr7\Request;
 use GuzzleHttp\RequestOptions;
 use MailchimpMarketing\ApiException;
-use MailchimpMarketing\Configuration;
-use MailchimpMarketing\HeaderSelector;
 use MailchimpMarketing\ObjectSerializer;
 
-class SearchMembersApi
+class SearchMembersApi extends BaseApi
 {
-    protected $client;
-    protected $config;
-    protected $headerSelector;
-
-    public function __construct(Configuration $config = null)
-    {
-        $this->client = new Client([
-            'defaults' => [
-                'timeout' => 120.0
-            ]
-        ]);
-        $this->headerSelector = new HeaderSelector();
-        $this->config = $config ?: new Configuration();
-    }
-
-    public function getConfig()
-    {
-        return $this->config;
-    }
-
     public function search($query, $fields = null, $exclude_fields = null, $list_id = null)
     {
         $response = $this->searchWithHttpInfo($query, $fields, $exclude_fields, $list_id);
diff --git a/lib/Api/SurveysApi.php b/lib/Api/SurveysApi.php
index 928e784..135d018 100644
--- a/lib/Api/SurveysApi.php
+++ b/lib/Api/SurveysApi.php
@@ -29,40 +29,16 @@
 
 namespace MailchimpMarketing\Api;
 
-use GuzzleHttp\Client;
-use GuzzleHttp\ClientInterface;
 use GuzzleHttp\Exception\RequestException;
 use GuzzleHttp\Psr7\MultipartStream;
 use GuzzleHttp\Psr7\Query;
 use GuzzleHttp\Psr7\Request;
 use GuzzleHttp\RequestOptions;
 use MailchimpMarketing\ApiException;
-use MailchimpMarketing\Configuration;
-use MailchimpMarketing\HeaderSelector;
 use MailchimpMarketing\ObjectSerializer;
 
-class SurveysApi
+class SurveysApi extends BaseApi
 {
-    protected $client;
-    protected $config;
-    protected $headerSelector;
-
-    public function __construct(Configuration $config = null)
-    {
-        $this->client = new Client([
-            'defaults' => [
-                'timeout' => 120.0
-            ]
-        ]);
-        $this->headerSelector = new HeaderSelector();
-        $this->config = $config ?: new Configuration();
-    }
-
-    public function getConfig()
-    {
-        return $this->config;
-    }
-
     public function publishSurvey($list_id, $survey_id)
     {
         $this->publishSurveyWithHttpInfo($list_id, $survey_id);
diff --git a/lib/Api/TemplateFoldersApi.php b/lib/Api/TemplateFoldersApi.php
index 6282b99..b1d0a44 100644
--- a/lib/Api/TemplateFoldersApi.php
+++ b/lib/Api/TemplateFoldersApi.php
@@ -29,40 +29,16 @@
 
 namespace MailchimpMarketing\Api;
 
-use GuzzleHttp\Client;
-use GuzzleHttp\ClientInterface;
 use GuzzleHttp\Exception\RequestException;
 use GuzzleHttp\Psr7\MultipartStream;
 use GuzzleHttp\Psr7\Query;
 use GuzzleHttp\Psr7\Request;
 use GuzzleHttp\RequestOptions;
 use MailchimpMarketing\ApiException;
-use MailchimpMarketing\Configuration;
-use MailchimpMarketing\HeaderSelector;
 use MailchimpMarketing\ObjectSerializer;
 
-class TemplateFoldersApi
+class TemplateFoldersApi extends BaseApi
 {
-    protected $client;
-    protected $config;
-    protected $headerSelector;
-
-    public function __construct(Configuration $config = null)
-    {
-        $this->client = new Client([
-            'defaults' => [
-                'timeout' => 120.0
-            ]
-        ]);
-        $this->headerSelector = new HeaderSelector();
-        $this->config = $config ?: new Configuration();
-    }
-
-    public function getConfig()
-    {
-        return $this->config;
-    }
-
     public function remove($folder_id)
     {
         $this->removeWithHttpInfo($folder_id);
diff --git a/lib/Api/TemplatesApi.php b/lib/Api/TemplatesApi.php
index 33fa6ac..255724b 100644
--- a/lib/Api/TemplatesApi.php
+++ b/lib/Api/TemplatesApi.php
@@ -29,40 +29,16 @@
 
 namespace MailchimpMarketing\Api;
 
-use GuzzleHttp\Client;
-use GuzzleHttp\ClientInterface;
 use GuzzleHttp\Exception\RequestException;
 use GuzzleHttp\Psr7\MultipartStream;
 use GuzzleHttp\Psr7\Query;
 use GuzzleHttp\Psr7\Request;
 use GuzzleHttp\RequestOptions;
 use MailchimpMarketing\ApiException;
-use MailchimpMarketing\Configuration;
-use MailchimpMarketing\HeaderSelector;
 use MailchimpMarketing\ObjectSerializer;
 
-class TemplatesApi
+class TemplatesApi extends BaseApi
 {
-    protected $client;
-    protected $config;
-    protected $headerSelector;
-
-    public function __construct(Configuration $config = null)
-    {
-        $this->client = new Client([
-            'defaults' => [
-                'timeout' => 120.0
-            ]
-        ]);
-        $this->headerSelector = new HeaderSelector();
-        $this->config = $config ?: new Configuration();
-    }
-
-    public function getConfig()
-    {
-        return $this->config;
-    }
-
     public function deleteTemplate($template_id)
     {
         $this->deleteTemplateWithHttpInfo($template_id);
diff --git a/lib/Api/VerifiedDomainsApi.php b/lib/Api/VerifiedDomainsApi.php
index 776909f..0f9e958 100644
--- a/lib/Api/VerifiedDomainsApi.php
+++ b/lib/Api/VerifiedDomainsApi.php
@@ -29,40 +29,16 @@
 
 namespace MailchimpMarketing\Api;
 
-use GuzzleHttp\Client;
-use GuzzleHttp\ClientInterface;
 use GuzzleHttp\Exception\RequestException;
 use GuzzleHttp\Psr7\MultipartStream;
 use GuzzleHttp\Psr7\Query;
 use GuzzleHttp\Psr7\Request;
 use GuzzleHttp\RequestOptions;
 use MailchimpMarketing\ApiException;
-use MailchimpMarketing\Configuration;
-use MailchimpMarketing\HeaderSelector;
 use MailchimpMarketing\ObjectSerializer;
 
-class VerifiedDomainsApi
+class VerifiedDomainsApi extends BaseApi
 {
-    protected $client;
-    protected $config;
-    protected $headerSelector;
-
-    public function __construct(Configuration $config = null)
-    {
-        $this->client = new Client([
-            'defaults' => [
-                'timeout' => 120.0
-            ]
-        ]);
-        $this->headerSelector = new HeaderSelector();
-        $this->config = $config ?: new Configuration();
-    }
-
-    public function getConfig()
-    {
-        return $this->config;
-    }
-
     public function createVerifiedDomain($body)
     {
         $response = $this->createVerifiedDomainWithHttpInfo($body);