diff --git a/src/Endpoint.php b/src/Endpoint.php
index 0686690..71d363a 100644
--- a/src/Endpoint.php
+++ b/src/Endpoint.php
@@ -6,4 +6,29 @@ use Lewisdale\Webmentions\Gateways\WebmentionGatewayInterface;
 
 class Endpoint {
     private readonly WebmentionGatewayInterface $gateway;
+
+    public function validateUrl(string $url) : bool {
+        return !!filter_var($url, FILTER_VALIDATE_URL);
+    }
+
+    public function receiveWebmention(string $source, string $target) : void
+    {
+        // Validate that both source and target are actual domains
+        if (!$this->validateUrl($source) || !$this->validateUrl($target))
+        {
+            return;
+        }
+
+        // Validate that the webmention target is a domain I care about
+        if (!str_contains($target, "https://lewisdale.dev")) {
+            // Should throw a Bad Request error
+            return;  
+        }
+
+        // Parse content from the source
+
+        // Store the webmention
+
+        // Send the appropriate response
+    }
 }
\ No newline at end of file
diff --git a/tests/EndpointTest.php b/tests/EndpointTest.php
new file mode 100644
index 0000000..778ef9f
--- /dev/null
+++ b/tests/EndpointTest.php
@@ -0,0 +1,16 @@
+<?php declare(strict_types=1);
+
+use Lewisdale\Webmentions\Endpoint;
+use PHPUnit\Framework\TestCase;
+use PHPUnit\Framework\Attributes\TestWith;
+
+class EndpointTest extends TestCase {
+    #[TestWith(["https://my.url.com", true])]
+    #[TestWith(["my.url.com", false])]
+    public function testValidatesUrls(string $url, bool $expected)
+    {
+        $endpoint = new Endpoint();
+        $this->assertEquals($expected, $endpoint->validateUrl($url), "Expected $url");
+    }
+}
+?>
\ No newline at end of file