diff --git a/src/main/php/com/openai/rest/OpenAIEndpoint.class.php b/src/main/php/com/openai/rest/OpenAIEndpoint.class.php
index 5e4ca11..e69322b 100644
--- a/src/main/php/com/openai/rest/OpenAIEndpoint.class.php
+++ b/src/main/php/com/openai/rest/OpenAIEndpoint.class.php
@@ -3,7 +3,11 @@
 use util\log\Traceable;
 use webservices\rest\Endpoint;
 
-/** @test com.openai.unittest.OpenAIEndpointTest */
+/**
+ * OpenAI REST API endpoint
+ *
+ * @test com.openai.unittest.OpenAIEndpointTest
+ */
 class OpenAIEndpoint implements Traceable {
   private $endpoint;
 
diff --git a/src/test/php/com/openai/unittest/OpenAIEndpointTest.class.php b/src/test/php/com/openai/unittest/OpenAIEndpointTest.class.php
index cc7003b..0d5518b 100644
--- a/src/test/php/com/openai/unittest/OpenAIEndpointTest.class.php
+++ b/src/test/php/com/openai/unittest/OpenAIEndpointTest.class.php
@@ -1,8 +1,9 @@
 <?php namespace com\openai\unittest;
 
 use com\openai\rest\OpenAIEndpoint;
-use test\{Assert, Test};
-use webservices\rest\TestEndpoint;
+use test\{Assert, Expect, Test};
+use util\log\{LogCategory, BufferedAppender};
+use webservices\rest\{TestEndpoint, UnexpectedStatus};
 
 class OpenAIEndpointTest {
   const URI= 'https://sk-test@api.openai.example.com/v1';
@@ -50,4 +51,10 @@ public function stream() {
       $endpoint->api('/chat/completions')->stream(['stream' => true])->result()
     );
   }
+
+  #[Test, Expect(UnexpectedStatus::class)]
+  public function invoke_non_existant_api() {
+    $endpoint= new OpenAIEndpoint($this->testingEndpoint());
+    $endpoint->api('/non-exisant')->invoke([]);
+  }
 }
\ No newline at end of file