diff --git a/app/structural/adapter/EmailSenderAdapter.php b/app/structural/adapter/EmailSenderAdapter.php
new file mode 100644
index 0000000..61ab0d9
--- /dev/null
+++ b/app/structural/adapter/EmailSenderAdapter.php
@@ -0,0 +1,10 @@
+<?php
+
+declare(strict_types=1);
+
+namespace app\structural\adapter;
+
+interface EmailSenderAdapter
+{
+    public function sendEmail(string $recipient, string $content): void;
+}
diff --git a/app/structural/adapter/ThirdPartyEmailClient.php b/app/structural/adapter/ThirdPartyEmailClient.php
new file mode 100644
index 0000000..dd65db2
--- /dev/null
+++ b/app/structural/adapter/ThirdPartyEmailClient.php
@@ -0,0 +1,22 @@
+<?php
+
+declare(strict_types=1);
+
+namespace app\structural\adapter;
+
+class ThirdPartyEmailClient
+{
+    public function __construct(
+        private string $apiKey,
+        private string $region,
+    ) {
+    }
+
+    public function sendEmail(
+        string $recipient,
+        string $content,
+    ): void {
+        echo sprintf("Using apiKey %s and region %s", $this->apiKey, $this->region);
+        echo sprintf("Sending email to %s and content %s", $recipient, $content);
+    }
+}
diff --git a/app/structural/adapter/ThirdPartyEmailSenderAdapter.php b/app/structural/adapter/ThirdPartyEmailSenderAdapter.php
new file mode 100644
index 0000000..a60f285
--- /dev/null
+++ b/app/structural/adapter/ThirdPartyEmailSenderAdapter.php
@@ -0,0 +1,17 @@
+<?php
+
+declare(strict_types=1);
+
+namespace app\structural\adapter;
+
+final class ThirdPartyEmailSenderAdapter implements EmailSenderAdapter
+{
+    public function __construct(private ThirdPartyEmailClient $emailClient)
+    {
+    }
+
+    public function sendEmail(string $recipient, string $content): void
+    {
+        $this->emailClient->sendEmail($recipient, $content);
+    }
+}
diff --git a/app/structural/adapter/docs/diagrams.md b/app/structural/adapter/docs/diagrams.md
new file mode 100644
index 0000000..b8ed0fa
--- /dev/null
+++ b/app/structural/adapter/docs/diagrams.md
@@ -0,0 +1,3 @@
+[![](https://mermaid.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)](https://mermaid-js.github.io/mermaid-live-editor/edit/#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)
+
+[![](https://mermaid.ink/img/eyJjb2RlIjoic2VxdWVuY2VEaWFncmFtXG4gICAgU2lnblVwU2VydmljZS0tPj5UaGlyZFBhcnR5RW1haWxTZW5kZXJBZGFwdGVyOiBJIHdhbnQgdG8gc2VuZCBhbiBlbWFpbCFcbiAgICBUaGlyZFBhcnR5RW1haWxTZW5kZXJBZGFwdGVyLS0-PlNpZ25VcFNlcnZpY2U6IEkganVzdCBuZWVkIGEgcmVjaWNwaWVudCBhbmQgdGhlIGNvbnRlbnQhXG4gICAgU2lnblVwU2VydmljZS0tPj5UaGlyZFBhcnR5RW1haWxTZW5kZXJBZGFwdGVyOiBPaCwgdGhhdCdzIGV4YWN0bHkgd2hhdCBJIGhhdmUhXG4gICAgVGhpcmRQYXJ0eUVtYWlsU2VuZGVyQWRhcHRlci0tPj5UaGlyZFBhcnR5RW1haWxDbGllbnQ6IFBsZWFzZSBzZW5kIHRoaXMgZW1haWxcbiAgICAgICAgICAgICIsIm1lcm1haWQiOnsidGhlbWUiOiJkZWZhdWx0In0sInVwZGF0ZUVkaXRvciI6ZmFsc2UsImF1dG9TeW5jIjp0cnVlLCJ1cGRhdGVEaWFncmFtIjpmYWxzZX0)](https://mermaid-js.github.io/mermaid-live-editor/edit/#eyJjb2RlIjoic2VxdWVuY2VEaWFncmFtXG4gICAgU2lnblVwU2VydmljZS0tPj5UaGlyZFBhcnR5RW1haWxTZW5kZXJBZGFwdGVyOiBJIHdhbnQgdG8gc2VuZCBhbiBlbWFpbCFcbiAgICBUaGlyZFBhcnR5RW1haWxTZW5kZXJBZGFwdGVyLS0-PlNpZ25VcFNlcnZpY2U6IEkganVzdCBuZWVkIGEgcmVjaWNwaWVudCBhbmQgdGhlIGNvbnRlbnQhXG4gICAgU2lnblVwU2VydmljZS0tPj5UaGlyZFBhcnR5RW1haWxTZW5kZXJBZGFwdGVyOiBPaCwgdGhhdCdzIGV4YWN0bHkgd2hhdCBJIGhhdmUhXG4gICAgVGhpcmRQYXJ0eUVtYWlsU2VuZGVyQWRhcHRlci0tPj5UaGlyZFBhcnR5RW1haWxDbGllbnQ6IFBsZWFzZSBzZW5kIHRoaXMgZW1haWxcbiAgICAgICAgICAgICIsIm1lcm1haWQiOiJ7XG4gIFwidGhlbWVcIjogXCJkZWZhdWx0XCJcbn0iLCJ1cGRhdGVFZGl0b3IiOmZhbHNlLCJhdXRvU3luYyI6dHJ1ZSwidXBkYXRlRGlhZ3JhbSI6ZmFsc2V9)
\ No newline at end of file
diff --git a/tests/structural/adapter/AdapterTest.php b/tests/structural/adapter/AdapterTest.php
new file mode 100644
index 0000000..15ac706
--- /dev/null
+++ b/tests/structural/adapter/AdapterTest.php
@@ -0,0 +1,35 @@
+<?php
+
+declare(strict_types=1);
+
+namespace structural\adapter;
+
+use app\structural\adapter\ThirdPartyEmailSenderAdapter;
+use app\structural\adapter\ThirdPartyEmailClient;
+use PHPUnit\Framework\TestCase;
+
+final class AdapterTest extends TestCase
+{
+    public function testThirdPartyEmailSenderAdapterAdapterUsesCorrectClient(): void
+    {
+        $emailClient = $this->createMock(ThirdPartyEmailClient::class);
+
+        $emailAdapter = new ThirdPartyEmailSenderAdapter($emailClient);
+
+        $emailClient->expects($this->once())
+            ->method('sendEmail');
+
+        $emailAdapter->sendEmail(
+            'email@email.com',
+            'I love design patterns');
+    }
+
+    public function testThirdPartyClient(): void
+    {
+        $emailClient = new ThirdPartyEmailClient('apiKey', 'region');
+        $emailClient->sendEmail('email@email.com', 'I love design patterns');
+
+        $this->expectOutputRegex('/Using apiKey apiKey and region region/');
+        $this->expectOutputRegex('/Sending email to email@email.com and content I love design patterns/');
+    }
+}
\ No newline at end of file