diff --git a/README.md b/README.md
index 7615644..7728bcb 100644
--- a/README.md
+++ b/README.md
@@ -1 +1,27 @@
 # simple php client for sendgrid marketing campaign apis
+
+## installation
+
+```shell
+composer require linkage/sendgrid-marketing-campaign-api-client
+```
+
+## usage
+
+```php
+
+$apiKey = 'get your api key from sendgrid admin screen';
+
+$sendgridClient = new \Linkage\SendgridMarketingCampaignApiClient\Client(
+    new \Linkage\SendgridMarketingCampaignApiClient\SendgridApiRequester($apiKey),
+);
+try {
+    $sendgridClient->createContactList(
+        new \Linkage\SendgridMarketingCampaignApiClient\ContactList\CreateContactListRequest('my new contact list'),
+    );
+} catch (\Linkage\SendgridMarketingCampaignApiClient\SendgridApiClientException $e) {
+    // handle client error
+} catch (\Linkage\SendgridMarketingCampaignApiClient\SendgridApiServerException $e) {
+    // handle server error
+}
+```
diff --git a/src/Client.php b/src/Client.php
index 990b169..78aab54 100644
--- a/src/Client.php
+++ b/src/Client.php
@@ -18,7 +18,7 @@
 readonly class Client implements ClientInterface
 {
     public function __construct(
-        private HttpRequester $requester,
+        private SendgridApiRequester $requester,
     ) {
     }
 
diff --git a/src/HttpRequester.php b/src/SendgridApiRequester.php
similarity index 62%
rename from src/HttpRequester.php
rename to src/SendgridApiRequester.php
index 8705ac7..45bd96b 100644
--- a/src/HttpRequester.php
+++ b/src/SendgridApiRequester.php
@@ -4,23 +4,58 @@
 
 namespace Linkage\SendgridMarketingCampaignApiClient;
 
-use GuzzleHttp\ClientInterface as HttpClient;
+use GuzzleHttp\Client as HttpClient;
+use GuzzleHttp\ClientInterface as HttpClientInterface;
 use GuzzleHttp\Exception\ClientException;
 use GuzzleHttp\Exception\GuzzleException;
 use GuzzleHttp\Exception\ServerException;
 use Symfony\Component\Serializer\SerializerInterface;
 
-readonly class HttpRequester
+readonly class SendgridApiRequester
 {
+    private HttpClientInterface $httpClient;
     private SerializerInterface $serializer;
 
     public function __construct(
-        private HttpClient $httpClient,
+        string $apiKey,
+        HttpClientInterface|null $httpClient = null,
         SerializerInterface|null $serializer = null,
     ) {
+        $this->httpClient = $httpClient ?? new HttpClient([
+            'base_uri' => 'https://api.sendgrid.com/v3',
+            'headers' => [
+                'Authorization' => sprintf('Bearer %s', $apiKey),
+            ],
+        ]);
         $this->serializer = $serializer ?? (new SerializerFactory())->create();
     }
 
+    /**
+     * @template T of object
+     *
+     * @param class-string<T> $responseClass
+     *
+     * @return T
+     *
+     * @throws SendgridApiClientException
+     * @throws SendgridApiServerException
+     */
+    public function get(string $path, string $responseClass)
+    {
+        try {
+            $response = $this->httpClient->request('GET', $path);
+        } catch (ClientException $e) {
+            throw new SendgridApiClientException($e->getResponse()->getBody()->getContents(), previous: $e);
+        } catch (ServerException|GuzzleException $e) {
+            throw new SendgridApiServerException($e->getMessage(), code: $e->getCode(), previous: $e);
+        }
+
+        $result = $this->serializer->deserialize($response->getBody()->getContents(), $responseClass, 'json');
+        \assert(\is_object($result) && $result instanceof $responseClass);
+
+        return $result;
+    }
+
     /**
      * @template T of object
      *
diff --git a/tests/HttpRequesterTest.php b/tests/SendgridApiRequesterTest.php
similarity index 92%
rename from tests/HttpRequesterTest.php
rename to tests/SendgridApiRequesterTest.php
index f99e498..7f5c1a5 100644
--- a/tests/HttpRequesterTest.php
+++ b/tests/SendgridApiRequesterTest.php
@@ -11,13 +11,13 @@
 use GuzzleHttp\Psr7\Response;
 use Linkage\SendgridMarketingCampaignApiClient\ContactList\CreateContactListRequest;
 use Linkage\SendgridMarketingCampaignApiClient\ContactList\CreateContactListResponse;
-use Linkage\SendgridMarketingCampaignApiClient\HttpRequester;
 use Linkage\SendgridMarketingCampaignApiClient\SendgridApiClientException;
+use Linkage\SendgridMarketingCampaignApiClient\SendgridApiRequester;
 use Linkage\SendgridMarketingCampaignApiClient\SendgridApiServerException;
 use PHPUnit\Framework\MockObject\MockObject;
 use PHPUnit\Framework\TestCase;
 
-class HttpRequesterTest extends TestCase
+class SendgridApiRequesterTest extends TestCase
 {
     private MockObject&ClientInterface $guzzleClientMock;
 
@@ -81,9 +81,10 @@ public function testPostServerError(): void
         );
     }
 
-    private function getSUT(): HttpRequester
+    private function getSUT(): SendgridApiRequester
     {
-        return new HttpRequester(
+        return new SendgridApiRequester(
+            'test',
             $this->guzzleClientMock,
         );
     }