diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index f5d1843e..310de04b 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -124,7 +124,7 @@ jobs:
 
   cs:
     runs-on: ubuntu-20.04
-    name: CS tests
+    name: CS & PHPSTAN tests
 
     steps:
     - uses: actions/checkout@v2
@@ -142,3 +142,6 @@ jobs:
 
     - name: Run CS tests
       run: vendor/bin/php-cs-fixer fix --config=.php_cs -v --dry-run --using-cache=no --show-progress=dots --diff $(git diff -- '*.php' --name-only --diff-filter=ACMRTUXB "HEAD~..HEAD")
+
+    - name: Run PHPSTAN
+      run: composer phpstan
diff --git a/.gitignore b/.gitignore
index c847cd4a..42f512e9 100644
--- a/.gitignore
+++ b/.gitignore
@@ -13,3 +13,4 @@
 .phpunit.result.cache
 /.ddev/mautic-preference
 /mautic
+.php_cs.cache
diff --git a/composer.json b/composer.json
index 1ae1c54e..b9b092cf 100644
--- a/composer.json
+++ b/composer.json
@@ -23,9 +23,12 @@
     "raveren/kint": "~0.9",
     "friendsofphp/php-cs-fixer": "~2.16.1",
     "phpunit/phpunit": "~9.5.0",
-    "brianium/paratest": "^6.2"
+    "brianium/paratest": "^6.2",
+    "phpstan/phpstan": "^0.12.78"
   },
   "scripts": {
-    "test": "vendor/bin/paratest"
+    "test": "vendor/bin/paratest",
+    "phpstan": "vendor/bin/phpstan analyse",
+    "cs": "vendor/bin/php-cs-fixer fix --config=.php_cs"
   }
 }
diff --git a/composer.lock b/composer.lock
index 594042a9..6408d094 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "12efc0f4bf879266563111bdc11dd051",
+    "content-hash": "8a2161a83a0ac0534a47ba6b3e6e0f74",
     "packages": [
         {
             "name": "psr/log",
@@ -51,9 +51,6 @@
                 "psr",
                 "psr-3"
             ],
-            "support": {
-                "source": "https://github.com/php-fig/log/tree/1.1.3"
-            },
             "time": "2020-03-23T09:12:05+00:00"
         }
     ],
@@ -482,10 +479,6 @@
                 "parser",
                 "php"
             ],
-            "support": {
-                "issues": "https://github.com/doctrine/lexer/issues",
-                "source": "https://github.com/doctrine/lexer/tree/1.2.1"
-            },
             "funding": [
                 {
                     "url": "https://www.doctrine-project.org/sponsorship.html",
@@ -929,10 +922,6 @@
                 "reflection",
                 "static analysis"
             ],
-            "support": {
-                "issues": "https://github.com/phpDocumentor/ReflectionCommon/issues",
-                "source": "https://github.com/phpDocumentor/ReflectionCommon/tree/2.x"
-            },
             "time": "2020-06-27T09:03:43+00:00"
         },
         {
@@ -985,10 +974,6 @@
                 }
             ],
             "description": "With this component, a library can provide support for annotations via DocBlocks or otherwise retrieve information that is embedded in a DocBlock.",
-            "support": {
-                "issues": "https://github.com/phpDocumentor/ReflectionDocBlock/issues",
-                "source": "https://github.com/phpDocumentor/ReflectionDocBlock/tree/master"
-            },
             "time": "2020-09-03T19:13:55+00:00"
         },
         {
@@ -1034,10 +1019,6 @@
                 }
             ],
             "description": "A PSR-5 based resolver of Class names, Types and Structural Element Names",
-            "support": {
-                "issues": "https://github.com/phpDocumentor/TypeResolver/issues",
-                "source": "https://github.com/phpDocumentor/TypeResolver/tree/1.4.0"
-            },
             "time": "2020-09-17T18:55:26+00:00"
         },
         {
@@ -1107,6 +1088,62 @@
             },
             "time": "2020-12-19T10:15:11+00:00"
         },
+        {
+            "name": "phpstan/phpstan",
+            "version": "0.12.78",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/phpstan/phpstan.git",
+                "reference": "eecce8d2ee3cac6769f37b4cb1998b2715f82984"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/phpstan/phpstan/zipball/eecce8d2ee3cac6769f37b4cb1998b2715f82984",
+                "reference": "eecce8d2ee3cac6769f37b4cb1998b2715f82984",
+                "shasum": ""
+            },
+            "require": {
+                "php": "^7.1|^8.0"
+            },
+            "conflict": {
+                "phpstan/phpstan-shim": "*"
+            },
+            "bin": [
+                "phpstan",
+                "phpstan.phar"
+            ],
+            "type": "library",
+            "extra": {
+                "branch-alias": {
+                    "dev-master": "0.12-dev"
+                }
+            },
+            "autoload": {
+                "files": [
+                    "bootstrap.php"
+                ]
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "description": "PHPStan - PHP Static Analysis Tool",
+            "funding": [
+                {
+                    "url": "https://github.com/ondrejmirtes",
+                    "type": "github"
+                },
+                {
+                    "url": "https://www.patreon.com/phpstan",
+                    "type": "patreon"
+                },
+                {
+                    "url": "https://tidelift.com/funding/github/packagist/phpstan/phpstan",
+                    "type": "tidelift"
+                }
+            ],
+            "time": "2021-02-20T13:24:36+00:00"
+        },
         {
             "name": "phpunit/php-code-coverage",
             "version": "9.2.5",
@@ -1563,10 +1600,6 @@
                 "container-interop",
                 "psr"
             ],
-            "support": {
-                "issues": "https://github.com/php-fig/container/issues",
-                "source": "https://github.com/php-fig/container/tree/master"
-            },
             "time": "2017-02-14T16:28:37+00:00"
         },
         {
@@ -1613,10 +1646,6 @@
                 "psr",
                 "psr-14"
             ],
-            "support": {
-                "issues": "https://github.com/php-fig/event-dispatcher/issues",
-                "source": "https://github.com/php-fig/event-dispatcher/tree/1.0.0"
-            },
             "time": "2019-01-08T18:20:26+00:00"
         },
         {
@@ -1668,10 +1697,6 @@
                 "kint",
                 "php"
             ],
-            "support": {
-                "issues": "https://github.com/raveren/kint/issues",
-                "source": "https://github.com/raveren/kint/tree/v0.9.1"
-            },
             "abandoned": "kint-php/kint",
             "time": "2014-08-11T11:44:51+00:00"
         },
@@ -2760,9 +2785,6 @@
             ],
             "description": "A generic function and convention to trigger deprecation notices",
             "homepage": "https://symfony.com",
-            "support": {
-                "source": "https://github.com/symfony/deprecation-contracts/tree/master"
-            },
             "funding": [
                 {
                     "url": "https://symfony.com/sponsor",
@@ -2924,9 +2946,6 @@
                 "interoperability",
                 "standards"
             ],
-            "support": {
-                "source": "https://github.com/symfony/event-dispatcher-contracts/tree/v2.2.0"
-            },
             "funding": [
                 {
                     "url": "https://symfony.com/sponsor",
@@ -3887,9 +3906,6 @@
                 "interoperability",
                 "standards"
             ],
-            "support": {
-                "source": "https://github.com/symfony/service-contracts/tree/master"
-            },
             "funding": [
                 {
                     "url": "https://symfony.com/sponsor",
@@ -4089,10 +4105,6 @@
                 }
             ],
             "description": "A small library for converting tokenized PHP source code into XML and potentially other formats",
-            "support": {
-                "issues": "https://github.com/theseer/tokenizer/issues",
-                "source": "https://github.com/theseer/tokenizer/tree/master"
-            },
             "funding": [
                 {
                     "url": "https://github.com/theseer",
@@ -4106,12 +4118,12 @@
             "version": "1.9.1",
             "source": {
                 "type": "git",
-                "url": "https://github.com/webmozarts/assert.git",
+                "url": "https://github.com/webmozart/assert.git",
                 "reference": "bafc69caeb4d49c39fd0779086c03a3738cbb389"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/webmozarts/assert/zipball/bafc69caeb4d49c39fd0779086c03a3738cbb389",
+                "url": "https://api.github.com/repos/webmozart/assert/zipball/bafc69caeb4d49c39fd0779086c03a3738cbb389",
                 "reference": "bafc69caeb4d49c39fd0779086c03a3738cbb389",
                 "shasum": ""
             },
@@ -4148,10 +4160,6 @@
                 "check",
                 "validate"
             ],
-            "support": {
-                "issues": "https://github.com/webmozart/assert/issues",
-                "source": "https://github.com/webmozart/assert/tree/master"
-            },
             "time": "2020-07-08T17:02:28+00:00"
         }
     ],
diff --git a/lib/Api/Api.php b/lib/Api/Api.php
index 01b3825f..03fc9422 100644
--- a/lib/Api/Api.php
+++ b/lib/Api/Api.php
@@ -10,7 +10,7 @@
 
 namespace Mautic\Api;
 
-use Mautic\Auth\ApiAuth;
+use Mautic\Auth\AbstractAuth;
 use Mautic\Auth\AuthInterface;
 use Mautic\QueryBuilder\QueryBuilder;
 use Psr\Log\LoggerAwareInterface;
@@ -86,7 +86,7 @@ class Api implements LoggerAwareInterface
     protected $searchCommands = [];
 
     /**
-     * @var ApiAuth
+     * @var AbstractAuth
      */
     private $auth;
 
diff --git a/lib/MauticApi.php b/lib/MauticApi.php
index 15c44ba8..b7bd04c9 100644
--- a/lib/MauticApi.php
+++ b/lib/MauticApi.php
@@ -37,7 +37,7 @@ public static function getContext($apiContext, AuthInterface $auth, $baseUrl = '
 
         $apiContext = ucfirst($apiContext);
 
-        if (!isset($context[$apiContext])) {
+        if (!isset($contexts[$apiContext])) {
             $class = 'Mautic\\Api\\'.$apiContext;
 
             if (!class_exists($class)) {
diff --git a/phpstan.neon b/phpstan.neon
new file mode 100644
index 00000000..5a13f47c
--- /dev/null
+++ b/phpstan.neon
@@ -0,0 +1,5 @@
+parameters:
+	level: 1
+	paths:
+		- lib
+		- tests
diff --git a/tests/Api/AssetsTest.php b/tests/Api/AssetsTest.php
index 05757bfe..fedccc9d 100644
--- a/tests/Api/AssetsTest.php
+++ b/tests/Api/AssetsTest.php
@@ -10,6 +10,8 @@
 
 namespace Mautic\Tests\Api;
 
+use Mautic\Api\Files;
+
 class AssetsTest extends MauticApiTestCase
 {
     protected $skipPayloadAssertion = ['file'];
@@ -37,12 +39,13 @@ public function testGetListOfSpecificIds()
     public function testCreateWithLocalFileGetAndDelete()
     {
         // Upload a testing file
-        $this->apiFiles = $this->getContext('files');
-        $this->apiFiles->setFolder('assets');
+        /** @var Files */
+        $apiFiles = $this->getContext('files');
+        $apiFiles->setFolder('assets');
         $fileRequest = [
             'file' => dirname(__DIR__).'/'.'mauticlogo.png',
         ];
-        $response = $this->apiFiles->create($fileRequest);
+        $response = $apiFiles->create($fileRequest);
         $this->assertErrors($response);
         $file = $response['file'];
 
diff --git a/tests/Api/CampaignsTest.php b/tests/Api/CampaignsTest.php
index 143055ac..042c171d 100644
--- a/tests/Api/CampaignsTest.php
+++ b/tests/Api/CampaignsTest.php
@@ -471,7 +471,7 @@ public function testCampaignContactEditEvent()
                 $date = new \DateTime($log['triggerDate'], new \DateTimeZone('UTC'));
                 $this->assertEquals($log['triggerDate'], $date->format('c'));
             } else {
-                $this->assertFalse(false, 'Event ID not recognized in the log.', var_export($event, true));
+                $this->assertFalse(var_export($event, true), 'Event ID not recognized in the log.');
             }
         }
 
diff --git a/tests/Api/FormsTest.php b/tests/Api/FormsTest.php
index a56005d2..cbc8c2c3 100644
--- a/tests/Api/FormsTest.php
+++ b/tests/Api/FormsTest.php
@@ -10,8 +10,13 @@
 
 namespace Mautic\Tests\Api;
 
+use Mautic\Api\Forms;
+
 class FormsTest extends MauticApiTestCase
 {
+    /** @var Forms */
+    protected $api;
+
     public function setUp(): void
     {
         $this->api         = $this->getContext('forms');
@@ -218,10 +223,15 @@ public function testFormSubmissions()
         $response = $this->api->getSubmissions($formId);
         $this->assertErrors($response);
 
-        foreach ($response['submissions'] as $submission) {
+        $submissions = $response['submissions'];
+        $this->assertTrue(count($submissions) > 0, 'Expected at least one form submission');
+
+        foreach ($submissions as $submission) {
             $this->assertSubmission($submission, $formId);
         }
 
+        $submission = end($submissions);
+
         // Try to fetch the last submission
         $response = $this->api->getSubmission($formId, $submission['id']);
         $this->assertErrors($response);
diff --git a/tests/Api/MauticApiTestCase.php b/tests/Api/MauticApiTestCase.php
index 2beaa7e7..58232ec3 100644
--- a/tests/Api/MauticApiTestCase.php
+++ b/tests/Api/MauticApiTestCase.php
@@ -43,7 +43,7 @@ protected function getAuth()
         $auth    = $apiAuth->newAuth($this->config, $authMethod);
         if ('BasicAuth' != $authMethod) {
             if (empty($this->config['refreshToken']) && !$auth->isAuthorized()) {
-                $this->assertTrue($authorized, 'Authorization failed. Check credentials in local.config.php.');
+                $this->assertTrue($auth->isAuthorized(), 'Authorization failed. Check credentials in local.config.php.');
             } else {
                 try {
                     $auth->validateAccessToken();
@@ -179,7 +179,7 @@ protected function standardTestGetListOfSpecificIds($callback = null)
             $itemIds[] = $response[$this->api->itemName()]['id'];
         }
 
-        if (is_callable($callback)) {
+        if (is_callable($callback) && !empty($response)) {
             // Allow support to make additional tests based on created associations with this item that
             // may not have create/edit endpoints
             $callback($response);
diff --git a/tests/Api/UtmTagsTest.php b/tests/Api/UtmTagsTest.php
index eadffe41..6339403c 100644
--- a/tests/Api/UtmTagsTest.php
+++ b/tests/Api/UtmTagsTest.php
@@ -150,7 +150,11 @@ protected function removeUtmTags($utmIds)
             }
         }
 
-        $this->assertSame(0, count($response[$this->api->itemName()]['utmtags']), 'Should be no more items');
+        if (!empty($response)) {
+            $this->assertSame(0, count($response[$this->api->itemName()]['utmtags']), 'Should be no more items');
+        } else {
+            throw new \Exception('Expected a reponse object');
+        }
     }
 
     protected function addUtmTags()