diff --git a/.gitattributes b/.gitattributes
index 88abbec..edc1f30 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -1,2 +1,3 @@
 /.* export-ignore
 /Examples export-ignore
+/phpunit.xml export-ignore
diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 81f5e16..b2b0a20 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -29,7 +29,7 @@ jobs:
       - uses: shivammathur/setup-php@v2
         with:
           php-version: ${{ matrix.php-version }}
-          extensions: none, curl, json, mbstring
+          extensions: none, curl, dom, json, mbstring, tokenizer, xml, xmlwriter
           coverage: none
 
       - id: composer-cache
@@ -44,3 +44,5 @@ jobs:
       - run: composer update --no-progress --classmap-authoritative
 
       - run: ./vendor/bin/parallel-lint . --exclude vendor
+
+      - run: ./vendor/bin/phpunit
diff --git a/.github/workflows/sca.yaml b/.github/workflows/sca.yaml
index e9b0f1d..4e8ed74 100644
--- a/.github/workflows/sca.yaml
+++ b/.github/workflows/sca.yaml
@@ -13,7 +13,7 @@ jobs:
       - uses: shivammathur/setup-php@v2
         with:
           php-version: 8.2
-          extensions: none, curl, dom, mbstring, simplexml, tokenizer
+          extensions: none, curl, dom, mbstring, simplexml, tokenizer, xml, xmlwriter
           coverage: none
 
       - run: composer update --no-progress --classmap-authoritative
diff --git a/composer.json b/composer.json
index 5ac66bb..0a79497 100644
--- a/composer.json
+++ b/composer.json
@@ -21,7 +21,8 @@
         "phpseclib/phpseclib": "^2 || ^3"
     },
     "require-dev": {
-        "php-parallel-lint/php-parallel-lint": "^1.3.2"
+        "php-parallel-lint/php-parallel-lint": "^1.3.2",
+        "phpunit/phpunit": "^5.7.27 || ^9.6.10"
     },
     "autoload": {
         "psr-4": {
@@ -31,6 +32,11 @@
             "**/Examples/"
         ]
     },
+    "autoload-dev": {
+        "psr-4": {
+            "Tpay\\Tests\\": "tests/"
+        }
+    },
     "extra": [
         {
             "engine": "PHP SDK"
diff --git a/phpunit.xml b/phpunit.xml
new file mode 100644
index 0000000..32f5fe9
--- /dev/null
+++ b/phpunit.xml
@@ -0,0 +1,33 @@
+<?xml version='1.0' encoding='UTF-8'?>
+
+<phpunit
+    xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance'
+    xsi:noNamespaceSchemaLocation='vendor/phpunit/phpunit/phpunit.xsd'
+    beStrictAboutChangesToGlobalState='true'
+    beStrictAboutOutputDuringTests='true'
+    beStrictAboutTodoAnnotatedTests='true'
+    bootstrap='./vendor/autoload.php'
+    cacheResult='false'
+    colors='true'
+    columns='max'
+    defaultTimeLimit='10'
+    enforceTimeLimit='true'
+    failOnRisky='true'
+    failOnWarning='true'
+    timeoutForSmallTests='10'
+    timeoutForMediumTests='20'
+    timeoutForLargeTests='30'
+    verbose='true'
+>
+    <testsuites>
+        <testsuite name='all'>
+            <directory>./tests</directory>
+        </testsuite>
+    </testsuites>
+
+    <php>
+        <ini name='display_errors' value='1' />
+        <ini name='display_startup_errors' value='1' />
+        <ini name='error_reporting' value='-1' />
+    </php>
+</phpunit>
diff --git a/tests/Model/ModelsTest.php b/tests/Model/ModelsTest.php
new file mode 100644
index 0000000..ec77c22
--- /dev/null
+++ b/tests/Model/ModelsTest.php
@@ -0,0 +1,42 @@
+<?php
+
+namespace Tpay\Tests\Model;
+
+use PHPUnit\Framework\TestCase;
+use RecursiveDirectoryIterator;
+use RecursiveIteratorIterator;
+use SplFileInfo;
+
+class ModelsTest extends TestCase
+{
+    /**
+     * @coversNothing
+     *
+     * @dataProvider dataModel
+     */
+    public function testModel($class)
+    {
+        self::assertTrue(class_exists($class) || interface_exists($class));
+    }
+
+    public static function dataModel()
+    {
+        $modelDirectory = realpath(__DIR__.'/../../Model');
+
+        /** @var SplFileInfo $fileInfo */
+        foreach (new RecursiveIteratorIterator(new RecursiveDirectoryIterator($modelDirectory)) as $fileInfo) {
+            if (!$fileInfo->isFile()) {
+                continue;
+            }
+
+            $className = 'tpaySDK\\Model\\'.substr(
+                $fileInfo->getRealPath(),
+                strlen($modelDirectory) + 1,
+                -4
+            );
+            $className = str_replace('/', '\\', $className);
+
+            yield $className => [$className];
+        }
+    }
+}