diff --git a/src/Platform/Bridge/Anthropic/Contract/AnthropicSet.php b/src/Platform/Bridge/Anthropic/Contract/AnthropicSet.php
new file mode 100644
index 00000000..39ecc935
--- /dev/null
+++ b/src/Platform/Bridge/Anthropic/Contract/AnthropicSet.php
@@ -0,0 +1,28 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PhpLlm\LlmChain\Platform\Bridge\Anthropic\Contract;
+
+use Symfony\Component\Serializer\Normalizer\NormalizerInterface;
+
+/**
+ * @author Denis Zunke <denis.zunke@gmail.com>
+ */
+final readonly class AnthropicSet
+{
+    /** @return array<NormalizerInterface> */
+    public static function get(): array
+    {
+        return [
+            new AssistantMessageNormalizer(),
+            new DocumentNormalizer(),
+            new DocumentUrlNormalizer(),
+            new ImageNormalizer(),
+            new ImageUrlNormalizer(),
+            new MessageBagNormalizer(),
+            new ToolCallMessageNormalizer(),
+            new ToolNormalizer(),
+        ];
+    }
+}
diff --git a/src/Platform/Bridge/Anthropic/PlatformFactory.php b/src/Platform/Bridge/Anthropic/PlatformFactory.php
index 87abe1f5..0bdce54f 100644
--- a/src/Platform/Bridge/Anthropic/PlatformFactory.php
+++ b/src/Platform/Bridge/Anthropic/PlatformFactory.php
@@ -4,15 +4,9 @@
 
 namespace PhpLlm\LlmChain\Platform\Bridge\Anthropic;
 
-use PhpLlm\LlmChain\Platform\Bridge\Anthropic\Contract\AssistantMessageNormalizer;
-use PhpLlm\LlmChain\Platform\Bridge\Anthropic\Contract\DocumentNormalizer;
-use PhpLlm\LlmChain\Platform\Bridge\Anthropic\Contract\DocumentUrlNormalizer;
-use PhpLlm\LlmChain\Platform\Bridge\Anthropic\Contract\ImageNormalizer;
-use PhpLlm\LlmChain\Platform\Bridge\Anthropic\Contract\ImageUrlNormalizer;
-use PhpLlm\LlmChain\Platform\Bridge\Anthropic\Contract\MessageBagNormalizer;
-use PhpLlm\LlmChain\Platform\Bridge\Anthropic\Contract\ToolCallMessageNormalizer;
-use PhpLlm\LlmChain\Platform\Bridge\Anthropic\Contract\ToolNormalizer;
+use PhpLlm\LlmChain\Platform\Bridge\Anthropic\Contract\AnthropicSet;
 use PhpLlm\LlmChain\Platform\Contract;
+use PhpLlm\LlmChain\Platform\ContractInterface;
 use PhpLlm\LlmChain\Platform\Platform;
 use Symfony\Component\HttpClient\EventSourceHttpClient;
 use Symfony\Contracts\HttpClient\HttpClientInterface;
@@ -27,22 +21,14 @@ public static function create(
         string $apiKey,
         string $version = '2023-06-01',
         ?HttpClientInterface $httpClient = null,
+        ?ContractInterface $contract = null,
     ): Platform {
         $httpClient = $httpClient instanceof EventSourceHttpClient ? $httpClient : new EventSourceHttpClient($httpClient);
 
         return new Platform(
             [new ModelClient($httpClient, $apiKey, $version)],
             [new ResponseConverter()],
-            Contract::create(
-                new AssistantMessageNormalizer(),
-                new DocumentNormalizer(),
-                new DocumentUrlNormalizer(),
-                new ImageNormalizer(),
-                new ImageUrlNormalizer(),
-                new MessageBagNormalizer(),
-                new ToolCallMessageNormalizer(),
-                new ToolNormalizer(),
-            )
+            $contract ?? Contract::create(...AnthropicSet::get()),
         );
     }
 }
diff --git a/src/Platform/Bridge/Azure/Meta/PlatformFactory.php b/src/Platform/Bridge/Azure/Meta/PlatformFactory.php
index 51e4c3d5..8b2a8ab6 100644
--- a/src/Platform/Bridge/Azure/Meta/PlatformFactory.php
+++ b/src/Platform/Bridge/Azure/Meta/PlatformFactory.php
@@ -4,6 +4,7 @@
 
 namespace PhpLlm\LlmChain\Platform\Bridge\Azure\Meta;
 
+use PhpLlm\LlmChain\Platform\ContractInterface;
 use PhpLlm\LlmChain\Platform\Platform;
 use Symfony\Component\HttpClient\HttpClient;
 use Symfony\Contracts\HttpClient\HttpClientInterface;
@@ -18,9 +19,10 @@ public static function create(
         #[\SensitiveParameter]
         string $apiKey,
         ?HttpClientInterface $httpClient = null,
+        ?ContractInterface $contract = null,
     ): Platform {
         $modelClient = new LlamaHandler($httpClient ?? HttpClient::create(), $baseUrl, $apiKey);
 
-        return new Platform([$modelClient], [$modelClient]);
+        return new Platform([$modelClient], [$modelClient], $contract);
     }
 }
diff --git a/src/Platform/Bridge/Azure/OpenAI/PlatformFactory.php b/src/Platform/Bridge/Azure/OpenAI/PlatformFactory.php
index 6e4e1288..dc5daab4 100644
--- a/src/Platform/Bridge/Azure/OpenAI/PlatformFactory.php
+++ b/src/Platform/Bridge/Azure/OpenAI/PlatformFactory.php
@@ -8,6 +8,7 @@
 use PhpLlm\LlmChain\Platform\Bridge\OpenAI\GPT\ResponseConverter;
 use PhpLlm\LlmChain\Platform\Bridge\OpenAI\Whisper\AudioNormalizer;
 use PhpLlm\LlmChain\Platform\Contract;
+use PhpLlm\LlmChain\Platform\ContractInterface;
 use PhpLlm\LlmChain\Platform\Platform;
 use Symfony\Component\HttpClient\EventSourceHttpClient;
 use Symfony\Contracts\HttpClient\HttpClientInterface;
@@ -24,6 +25,7 @@ public static function create(
         #[\SensitiveParameter]
         string $apiKey,
         ?HttpClientInterface $httpClient = null,
+        ?ContractInterface $contract = null,
     ): Platform {
         $httpClient = $httpClient instanceof EventSourceHttpClient ? $httpClient : new EventSourceHttpClient($httpClient);
         $embeddingsResponseFactory = new EmbeddingsModelClient($httpClient, $baseUrl, $deployment, $apiVersion, $apiKey);
@@ -33,7 +35,7 @@ public static function create(
         return new Platform(
             [$GPTResponseFactory, $embeddingsResponseFactory, $whisperResponseFactory],
             [new ResponseConverter(), new Embeddings\ResponseConverter(), new \PhpLlm\LlmChain\Platform\Bridge\OpenAI\Whisper\ResponseConverter()],
-            Contract::create(new AudioNormalizer()),
+            $contract ?? Contract::create(new AudioNormalizer()),
         );
     }
 }
diff --git a/src/Platform/Bridge/Bedrock/Platform.php b/src/Platform/Bridge/Bedrock/Platform.php
index 9dd887f0..b0804810 100644
--- a/src/Platform/Bridge/Bedrock/Platform.php
+++ b/src/Platform/Bridge/Bedrock/Platform.php
@@ -6,6 +6,7 @@
 use PhpLlm\LlmChain\Platform\Bridge\Bedrock\Nova\Contract as NovaContract;
 use PhpLlm\LlmChain\Platform\Bridge\Meta\Contract as LlamaContract;
 use PhpLlm\LlmChain\Platform\Contract;
+use PhpLlm\LlmChain\Platform\ContractInterface;
 use PhpLlm\LlmChain\Platform\Exception\RuntimeException;
 use PhpLlm\LlmChain\Platform\Model;
 use PhpLlm\LlmChain\Platform\PlatformInterface;
@@ -26,7 +27,7 @@ class Platform implements PlatformInterface
      */
     public function __construct(
         iterable $modelClients,
-        private ?Contract $contract = null,
+        private ?ContractInterface $contract = null,
     ) {
         $this->contract = $contract ?? Contract::create(
             new AnthropicContract\AssistantMessageNormalizer(),
diff --git a/src/Platform/Bridge/Bedrock/PlatformFactory.php b/src/Platform/Bridge/Bedrock/PlatformFactory.php
index e2315682..7528e96f 100644
--- a/src/Platform/Bridge/Bedrock/PlatformFactory.php
+++ b/src/Platform/Bridge/Bedrock/PlatformFactory.php
@@ -8,6 +8,7 @@
 use PhpLlm\LlmChain\Platform\Bridge\Bedrock\Anthropic\ClaudeHandler;
 use PhpLlm\LlmChain\Platform\Bridge\Bedrock\Meta\LlamaModelClient;
 use PhpLlm\LlmChain\Platform\Bridge\Bedrock\Nova\NovaHandler;
+use PhpLlm\LlmChain\Platform\ContractInterface;
 
 /**
  * @author Björn Altmann
@@ -16,11 +17,12 @@
 {
     public static function create(
         BedrockRuntimeClient $bedrockRuntimeClient = new BedrockRuntimeClient(),
+        ?ContractInterface $contract = null,
     ): Platform {
         $modelClient[] = new ClaudeHandler($bedrockRuntimeClient);
         $modelClient[] = new NovaHandler($bedrockRuntimeClient);
         $modelClient[] = new LlamaModelClient($bedrockRuntimeClient);
 
-        return new Platform($modelClient);
+        return new Platform($modelClient, $contract);
     }
 }
diff --git a/src/Platform/Bridge/Google/Contract/GoogleSet.php b/src/Platform/Bridge/Google/Contract/GoogleSet.php
new file mode 100644
index 00000000..d4e0661c
--- /dev/null
+++ b/src/Platform/Bridge/Google/Contract/GoogleSet.php
@@ -0,0 +1,25 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PhpLlm\LlmChain\Platform\Bridge\Google\Contract;
+
+use Symfony\Component\Serializer\Normalizer\NormalizerInterface;
+
+/**
+ * @author Denis Zunke <denis.zunke@gmail.com>
+ */
+final readonly class GoogleSet
+{
+    /** @return array<NormalizerInterface> */
+    public static function get(): array
+    {
+        return [
+            new AssistantMessageNormalizer(),
+            new MessageBagNormalizer(),
+            new ToolNormalizer(),
+            new ToolCallMessageNormalizer(),
+            new UserMessageNormalizer(),
+        ];
+    }
+}
diff --git a/src/Platform/Bridge/Google/PlatformFactory.php b/src/Platform/Bridge/Google/PlatformFactory.php
index da224f29..5a08a420 100644
--- a/src/Platform/Bridge/Google/PlatformFactory.php
+++ b/src/Platform/Bridge/Google/PlatformFactory.php
@@ -4,13 +4,10 @@
 
 namespace PhpLlm\LlmChain\Platform\Bridge\Google;
 
-use PhpLlm\LlmChain\Platform\Bridge\Google\Contract\AssistantMessageNormalizer;
-use PhpLlm\LlmChain\Platform\Bridge\Google\Contract\MessageBagNormalizer;
-use PhpLlm\LlmChain\Platform\Bridge\Google\Contract\ToolCallMessageNormalizer;
-use PhpLlm\LlmChain\Platform\Bridge\Google\Contract\ToolNormalizer;
-use PhpLlm\LlmChain\Platform\Bridge\Google\Contract\UserMessageNormalizer;
+use PhpLlm\LlmChain\Platform\Bridge\Google\Contract\GoogleSet;
 use PhpLlm\LlmChain\Platform\Bridge\Google\Embeddings\ModelClient;
 use PhpLlm\LlmChain\Platform\Contract;
+use PhpLlm\LlmChain\Platform\ContractInterface;
 use PhpLlm\LlmChain\Platform\Platform;
 use Symfony\Component\HttpClient\EventSourceHttpClient;
 use Symfony\Contracts\HttpClient\HttpClientInterface;
@@ -24,17 +21,16 @@ public static function create(
         #[\SensitiveParameter]
         string $apiKey,
         ?HttpClientInterface $httpClient = null,
+        ?ContractInterface $contract = null,
     ): Platform {
         $httpClient = $httpClient instanceof EventSourceHttpClient ? $httpClient : new EventSourceHttpClient($httpClient);
         $responseHandler = new ModelHandler($httpClient, $apiKey);
         $embeddings = new ModelClient($httpClient, $apiKey);
 
-        return new Platform([$responseHandler, $embeddings], [$responseHandler, $embeddings], Contract::create(
-            new AssistantMessageNormalizer(),
-            new MessageBagNormalizer(),
-            new ToolNormalizer(),
-            new ToolCallMessageNormalizer(),
-            new UserMessageNormalizer(),
-        ));
+        return new Platform(
+            [$responseHandler, $embeddings],
+            [$responseHandler, $embeddings],
+            $contract ?? Contract::create(...GoogleSet::get()),
+        );
     }
 }
diff --git a/src/Platform/Bridge/HuggingFace/PlatformFactory.php b/src/Platform/Bridge/HuggingFace/PlatformFactory.php
index e46ae69a..c488bbc5 100644
--- a/src/Platform/Bridge/HuggingFace/PlatformFactory.php
+++ b/src/Platform/Bridge/HuggingFace/PlatformFactory.php
@@ -7,6 +7,7 @@
 use PhpLlm\LlmChain\Platform\Bridge\HuggingFace\Contract\FileNormalizer;
 use PhpLlm\LlmChain\Platform\Bridge\HuggingFace\Contract\MessageBagNormalizer;
 use PhpLlm\LlmChain\Platform\Contract;
+use PhpLlm\LlmChain\Platform\ContractInterface;
 use PhpLlm\LlmChain\Platform\Platform;
 use Symfony\Component\HttpClient\EventSourceHttpClient;
 use Symfony\Contracts\HttpClient\HttpClientInterface;
@@ -21,13 +22,14 @@ public static function create(
         string $apiKey,
         string $provider = Provider::HF_INFERENCE,
         ?HttpClientInterface $httpClient = null,
+        ?ContractInterface $contract = null,
     ): Platform {
         $httpClient = $httpClient instanceof EventSourceHttpClient ? $httpClient : new EventSourceHttpClient($httpClient);
 
         return new Platform(
             [new ModelClient($httpClient, $provider, $apiKey)],
             [new ResponseConverter()],
-            Contract::create(
+            $contract ?? Contract::create(
                 new FileNormalizer(),
                 new MessageBagNormalizer(),
             ),
diff --git a/src/Platform/Bridge/Mistral/PlatformFactory.php b/src/Platform/Bridge/Mistral/PlatformFactory.php
index 47ab83a0..66554fcf 100644
--- a/src/Platform/Bridge/Mistral/PlatformFactory.php
+++ b/src/Platform/Bridge/Mistral/PlatformFactory.php
@@ -10,6 +10,7 @@
 use PhpLlm\LlmChain\Platform\Bridge\Mistral\Llm\ModelClient as MistralModelClient;
 use PhpLlm\LlmChain\Platform\Bridge\Mistral\Llm\ResponseConverter as MistralResponseConverter;
 use PhpLlm\LlmChain\Platform\Contract;
+use PhpLlm\LlmChain\Platform\ContractInterface;
 use PhpLlm\LlmChain\Platform\Platform;
 use Symfony\Component\HttpClient\EventSourceHttpClient;
 use Symfony\Contracts\HttpClient\HttpClientInterface;
@@ -23,13 +24,14 @@ public static function create(
         #[\SensitiveParameter]
         string $apiKey,
         ?HttpClientInterface $httpClient = null,
+        ?ContractInterface $contract = null,
     ): Platform {
         $httpClient = $httpClient instanceof EventSourceHttpClient ? $httpClient : new EventSourceHttpClient($httpClient);
 
         return new Platform(
             [new EmbeddingsModelClient($httpClient, $apiKey), new MistralModelClient($httpClient, $apiKey)],
             [new EmbeddingsResponseConverter(), new MistralResponseConverter()],
-            Contract::create(new ToolNormalizer()),
+            $contract ?? Contract::create(new ToolNormalizer()),
         );
     }
 }
diff --git a/src/Platform/Bridge/Ollama/PlatformFactory.php b/src/Platform/Bridge/Ollama/PlatformFactory.php
index c07e9699..b0134b71 100644
--- a/src/Platform/Bridge/Ollama/PlatformFactory.php
+++ b/src/Platform/Bridge/Ollama/PlatformFactory.php
@@ -4,6 +4,7 @@
 
 namespace PhpLlm\LlmChain\Platform\Bridge\Ollama;
 
+use PhpLlm\LlmChain\Platform\ContractInterface;
 use PhpLlm\LlmChain\Platform\Platform;
 use Symfony\Component\HttpClient\EventSourceHttpClient;
 use Symfony\Contracts\HttpClient\HttpClientInterface;
@@ -16,10 +17,11 @@ final class PlatformFactory
     public static function create(
         string $hostUrl = 'http://localhost:11434',
         ?HttpClientInterface $httpClient = null,
+        ?ContractInterface $contract = null,
     ): Platform {
         $httpClient = $httpClient instanceof EventSourceHttpClient ? $httpClient : new EventSourceHttpClient($httpClient);
         $handler = new LlamaModelHandler($httpClient, $hostUrl);
 
-        return new Platform([$handler], [$handler]);
+        return new Platform([$handler], [$handler], $contract);
     }
 }
diff --git a/src/Platform/Bridge/OpenAI/PlatformFactory.php b/src/Platform/Bridge/OpenAI/PlatformFactory.php
index f27c76b7..b98a7bc6 100644
--- a/src/Platform/Bridge/OpenAI/PlatformFactory.php
+++ b/src/Platform/Bridge/OpenAI/PlatformFactory.php
@@ -13,6 +13,7 @@
 use PhpLlm\LlmChain\Platform\Bridge\OpenAI\Whisper\ModelClient as WhisperModelClient;
 use PhpLlm\LlmChain\Platform\Bridge\OpenAI\Whisper\ResponseConverter as WhisperResponseConverter;
 use PhpLlm\LlmChain\Platform\Contract;
+use PhpLlm\LlmChain\Platform\ContractInterface;
 use PhpLlm\LlmChain\Platform\Platform;
 use Symfony\Component\HttpClient\EventSourceHttpClient;
 use Symfony\Contracts\HttpClient\HttpClientInterface;
@@ -26,6 +27,7 @@ public static function create(
         #[\SensitiveParameter]
         string $apiKey,
         ?HttpClientInterface $httpClient = null,
+        ?ContractInterface $contract = null,
     ): Platform {
         $httpClient = $httpClient instanceof EventSourceHttpClient ? $httpClient : new EventSourceHttpClient($httpClient);
 
@@ -44,7 +46,7 @@ public static function create(
                 $dallEModelClient,
                 new WhisperResponseConverter(),
             ],
-            Contract::create(new AudioNormalizer()),
+            $contract ?? Contract::create(new AudioNormalizer()),
         );
     }
 }
diff --git a/src/Platform/Bridge/OpenRouter/PlatformFactory.php b/src/Platform/Bridge/OpenRouter/PlatformFactory.php
index bd0cb684..6bac24fc 100644
--- a/src/Platform/Bridge/OpenRouter/PlatformFactory.php
+++ b/src/Platform/Bridge/OpenRouter/PlatformFactory.php
@@ -8,6 +8,7 @@
 use PhpLlm\LlmChain\Platform\Bridge\Google\Contract\MessageBagNormalizer;
 use PhpLlm\LlmChain\Platform\Bridge\Google\Contract\UserMessageNormalizer;
 use PhpLlm\LlmChain\Platform\Contract;
+use PhpLlm\LlmChain\Platform\ContractInterface;
 use PhpLlm\LlmChain\Platform\Platform;
 use Symfony\Component\HttpClient\EventSourceHttpClient;
 use Symfony\Contracts\HttpClient\HttpClientInterface;
@@ -21,14 +22,19 @@ public static function create(
         #[\SensitiveParameter]
         string $apiKey,
         ?HttpClientInterface $httpClient = null,
+        ?ContractInterface $contract = null,
     ): Platform {
         $httpClient = $httpClient instanceof EventSourceHttpClient ? $httpClient : new EventSourceHttpClient($httpClient);
         $handler = new Client($httpClient, $apiKey);
 
-        return new Platform([$handler], [$handler], Contract::create(
-            new AssistantMessageNormalizer(),
-            new MessageBagNormalizer(),
-            new UserMessageNormalizer(),
-        ));
+        return new Platform(
+            [$handler],
+            [$handler],
+            $contract ?? Contract::create(
+                new AssistantMessageNormalizer(),
+                new MessageBagNormalizer(),
+                new UserMessageNormalizer(),
+            ),
+        );
     }
 }
diff --git a/src/Platform/Bridge/Replicate/PlatformFactory.php b/src/Platform/Bridge/Replicate/PlatformFactory.php
index f150ff0a..48cfa7a7 100644
--- a/src/Platform/Bridge/Replicate/PlatformFactory.php
+++ b/src/Platform/Bridge/Replicate/PlatformFactory.php
@@ -6,6 +6,7 @@
 
 use PhpLlm\LlmChain\Platform\Bridge\Replicate\Contract\LlamaMessageBagNormalizer;
 use PhpLlm\LlmChain\Platform\Contract;
+use PhpLlm\LlmChain\Platform\ContractInterface;
 use PhpLlm\LlmChain\Platform\Platform;
 use Symfony\Component\Clock\Clock;
 use Symfony\Component\HttpClient\HttpClient;
@@ -20,11 +21,12 @@ public static function create(
         #[\SensitiveParameter]
         string $apiKey,
         ?HttpClientInterface $httpClient = null,
+        ?ContractInterface $contract = null,
     ): Platform {
         return new Platform(
             [new LlamaModelClient(new Client($httpClient ?? HttpClient::create(), new Clock(), $apiKey))],
             [new LlamaResponseConverter()],
-            Contract::create(new LlamaMessageBagNormalizer()),
+            $contract ?? Contract::create(new LlamaMessageBagNormalizer()),
         );
     }
 }
diff --git a/src/Platform/Bridge/Voyage/PlatformFactory.php b/src/Platform/Bridge/Voyage/PlatformFactory.php
index f4bb9ec6..cf507bb4 100644
--- a/src/Platform/Bridge/Voyage/PlatformFactory.php
+++ b/src/Platform/Bridge/Voyage/PlatformFactory.php
@@ -4,6 +4,7 @@
 
 namespace PhpLlm\LlmChain\Platform\Bridge\Voyage;
 
+use PhpLlm\LlmChain\Platform\ContractInterface;
 use PhpLlm\LlmChain\Platform\Platform;
 use Symfony\Component\HttpClient\EventSourceHttpClient;
 use Symfony\Contracts\HttpClient\HttpClientInterface;
@@ -17,10 +18,11 @@ public static function create(
         #[\SensitiveParameter]
         string $apiKey,
         ?HttpClientInterface $httpClient = null,
+        ?ContractInterface $contract = null,
     ): Platform {
         $httpClient = $httpClient instanceof EventSourceHttpClient ? $httpClient : new EventSourceHttpClient($httpClient);
         $handler = new ModelHandler($httpClient, $apiKey);
 
-        return new Platform([$handler], [$handler]);
+        return new Platform([$handler], [$handler], $contract);
     }
 }
diff --git a/src/Platform/Contract.php b/src/Platform/Contract.php
index dff53424..e85b53f3 100644
--- a/src/Platform/Contract.php
+++ b/src/Platform/Contract.php
@@ -4,17 +4,7 @@
 
 namespace PhpLlm\LlmChain\Platform;
 
-use PhpLlm\LlmChain\Platform\Contract\Normalizer\Message\AssistantMessageNormalizer;
-use PhpLlm\LlmChain\Platform\Contract\Normalizer\Message\Content\AudioNormalizer;
-use PhpLlm\LlmChain\Platform\Contract\Normalizer\Message\Content\ImageNormalizer;
-use PhpLlm\LlmChain\Platform\Contract\Normalizer\Message\Content\ImageUrlNormalizer;
-use PhpLlm\LlmChain\Platform\Contract\Normalizer\Message\Content\TextNormalizer;
-use PhpLlm\LlmChain\Platform\Contract\Normalizer\Message\MessageBagNormalizer;
-use PhpLlm\LlmChain\Platform\Contract\Normalizer\Message\SystemMessageNormalizer;
-use PhpLlm\LlmChain\Platform\Contract\Normalizer\Message\ToolCallMessageNormalizer;
-use PhpLlm\LlmChain\Platform\Contract\Normalizer\Message\UserMessageNormalizer;
-use PhpLlm\LlmChain\Platform\Contract\Normalizer\Response\ToolCallNormalizer;
-use PhpLlm\LlmChain\Platform\Contract\Normalizer\ToolNormalizer;
+use PhpLlm\LlmChain\Platform\Contract\PlatformSet;
 use PhpLlm\LlmChain\Platform\Tool\Tool;
 use Symfony\Component\Serializer\Normalizer\AbstractObjectNormalizer;
 use Symfony\Component\Serializer\Normalizer\NormalizerInterface;
@@ -23,7 +13,7 @@
 /**
  * @author Christopher Hertel <mail@christopher-hertel.de>
  */
-final readonly class Contract
+final readonly class Contract implements ContractInterface
 {
     public const CONTEXT_MODEL = 'model';
 
@@ -34,27 +24,8 @@ public function __construct(
 
     public static function create(NormalizerInterface ...$normalizer): self
     {
-        // Messages
-        $normalizer[] = new MessageBagNormalizer();
-        $normalizer[] = new AssistantMessageNormalizer();
-        $normalizer[] = new SystemMessageNormalizer();
-        $normalizer[] = new ToolCallMessageNormalizer();
-        $normalizer[] = new UserMessageNormalizer();
-
-        // Message Content
-        $normalizer[] = new AudioNormalizer();
-        $normalizer[] = new ImageNormalizer();
-        $normalizer[] = new ImageUrlNormalizer();
-        $normalizer[] = new TextNormalizer();
-
-        // Options
-        $normalizer[] = new ToolNormalizer();
-
-        // Response
-        $normalizer[] = new ToolCallNormalizer();
-
         return new self(
-            new Serializer($normalizer),
+            new Serializer(array_merge($normalizer, PlatformSet::get())),
         );
     }
 
diff --git a/src/Platform/Contract/PlatformSet.php b/src/Platform/Contract/PlatformSet.php
new file mode 100644
index 00000000..4bf6bfe4
--- /dev/null
+++ b/src/Platform/Contract/PlatformSet.php
@@ -0,0 +1,49 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PhpLlm\LlmChain\Platform\Contract;
+
+use PhpLlm\LlmChain\Platform\Contract\Normalizer\Message\AssistantMessageNormalizer;
+use PhpLlm\LlmChain\Platform\Contract\Normalizer\Message\Content\AudioNormalizer;
+use PhpLlm\LlmChain\Platform\Contract\Normalizer\Message\Content\ImageNormalizer;
+use PhpLlm\LlmChain\Platform\Contract\Normalizer\Message\Content\ImageUrlNormalizer;
+use PhpLlm\LlmChain\Platform\Contract\Normalizer\Message\Content\TextNormalizer;
+use PhpLlm\LlmChain\Platform\Contract\Normalizer\Message\MessageBagNormalizer;
+use PhpLlm\LlmChain\Platform\Contract\Normalizer\Message\SystemMessageNormalizer;
+use PhpLlm\LlmChain\Platform\Contract\Normalizer\Message\ToolCallMessageNormalizer;
+use PhpLlm\LlmChain\Platform\Contract\Normalizer\Message\UserMessageNormalizer;
+use PhpLlm\LlmChain\Platform\Contract\Normalizer\Response\ToolCallNormalizer;
+use PhpLlm\LlmChain\Platform\Contract\Normalizer\ToolNormalizer;
+use Symfony\Component\Serializer\Normalizer\NormalizerInterface;
+
+/**
+ * @author Denis Zunke <denis.zunke@gmail.com>
+ */
+final readonly class PlatformSet
+{
+    /** @return array<NormalizerInterface> */
+    public static function get(): array
+    {
+        return [
+            // Messages
+            new MessageBagNormalizer(),
+            new AssistantMessageNormalizer(),
+            new SystemMessageNormalizer(),
+            new ToolCallMessageNormalizer(),
+            new UserMessageNormalizer(),
+
+            // Message Content
+            new AudioNormalizer(),
+            new ImageNormalizer(),
+            new ImageUrlNormalizer(),
+            new TextNormalizer(),
+
+            // Options
+            new ToolNormalizer(),
+
+            // Response
+            new ToolCallNormalizer(),
+        ];
+    }
+}
diff --git a/src/Platform/ContractInterface.php b/src/Platform/ContractInterface.php
new file mode 100644
index 00000000..a961aa6d
--- /dev/null
+++ b/src/Platform/ContractInterface.php
@@ -0,0 +1,27 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PhpLlm\LlmChain\Platform;
+
+use PhpLlm\LlmChain\Platform\Tool\Tool;
+
+/**
+ * @author Denis Zunke <denis.zunke@gmail.com>
+ */
+interface ContractInterface
+{
+    /**
+     * @param object|array<string|int, mixed>|string $input
+     *
+     * @return array<string, mixed>|string
+     */
+    public function createRequestPayload(Model $model, object|array|string $input): string|array;
+
+    /**
+     * @param Tool[] $tools
+     *
+     * @return array<string, mixed>
+     */
+    public function createToolOption(array $tools, Model $model): array;
+}
diff --git a/src/Platform/Platform.php b/src/Platform/Platform.php
index 369eb228..f525fbb5 100644
--- a/src/Platform/Platform.php
+++ b/src/Platform/Platform.php
@@ -31,7 +31,7 @@ final class Platform implements PlatformInterface
     public function __construct(
         iterable $modelClients,
         iterable $responseConverter,
-        private ?Contract $contract = null,
+        private ?ContractInterface $contract = null,
     ) {
         $this->contract = $contract ?? Contract::create();
         $this->modelClients = $modelClients instanceof \Traversable ? iterator_to_array($modelClients) : $modelClients;