feat: add a generic API request interface

This public, generic interface is useful for making arbitrary API calls to the EasyPost API that
are not yet supported by the client library's services. When possible, the service for your use case
should be used instead as it provides a more convenient and higher-level interface depending on the endpoint.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

Author: Justintime50

lib/EasyPost/EasyPostClient.php

@@ -6,7 +6,9 @@
 use EasyPost\Exception\General\EasyPostException;
 use EasyPost\Hook\RequestHook;
 use EasyPost\Hook\ResponseHook;
+use EasyPost\Http\Requestor;
 use EasyPost\Service\AddressService;
+use EasyPost\Util\InternalUtil;
 use EasyPost\Service\ApiKeyService;
 use EasyPost\Service\BaseService;
 use EasyPost\Service\BatchService;
@@ -260,4 +262,23 @@ public function unsubscribeFromResponseHook(callable $function): void
     {
         $this->responseEvent->removeHandler($function);
     }
+
+    /**
+     * Make an API call to the EasyPost API.
+     *
+     * This public, generic interface is useful for making arbitrary API calls to the EasyPost API that
+     * are not yet supported by the client library's services. When possible, the service for your use case
+     * should be used instead as it provides a more convenient and higher-level interface depending on the endpoint.
+     *
+     * @param string $method
+     * @param string $endpoint
+     * @param mixed $params
+     * @return mixed
+     */
+    public function makeApiCall(string $method, string $endpoint, mixed $params = null): mixed
+    {
+        $response = Requestor::request($this, $method, $endpoint, $params);
+
+        return InternalUtil::convertToEasyPostObject($this, $response);
+    }
 }

test/EasyPost/EasyPostClientTest.php

@@ -8,6 +8,22 @@
 
 class EasyPostClientTest extends TestCase
 {
+    /**
+     * Setup the testing environment for this file.
+     */
+    public static function setUpBeforeClass(): void
+    {
+        TestUtil::setupVcrTests();
+    }
+
+    /**
+     * Cleanup the testing environment once finished.
+     */
+    public static function tearDownAfterClass(): void
+    {
+        TestUtil::teardownVcrTests();
+    }
+
     /**
      * Test setting and getting the API key for different EasyPostClients.
      */
@@ -66,4 +82,19 @@ public function testInvalidServiceProperty(): void
             );
         }
     }
+
+    /**
+     * Test making an API call using the generic makeApiCall method.
+     */
+    public function testMakeApiCall(): void
+    {
+        TestUtil::setupCassette('client/makeApiCall.yml');
+
+        $client = new EasyPostClient((string)getenv('EASYPOST_TEST_API_KEY'));
+
+        $response = $client->makeApiCall('get', '/addresses', ['page_size' => 1]);
+
+        $this->assertCount(1, $response['addresses']);
+        $this->assertEquals('Address', $response['addresses'][0]['object']);
+    }
 }