fix: usage of Claude without system prompt

Author: chr-hertel

examples/toolbox-wikipedia.php

@@ -1,7 +1,7 @@
 <?php
 
-use PhpLlm\LlmChain\Bridge\OpenAI\GPT;
-use PhpLlm\LlmChain\Bridge\OpenAI\PlatformFactory;
+use PhpLlm\LlmChain\Bridge\Anthropic\Claude;
+use PhpLlm\LlmChain\Bridge\Anthropic\PlatformFactory;
 use PhpLlm\LlmChain\Chain;
 use PhpLlm\LlmChain\Chain\Toolbox\ChainProcessor;
 use PhpLlm\LlmChain\Chain\Toolbox\Tool\Wikipedia;
@@ -14,13 +14,13 @@
 require_once dirname(__DIR__).'/vendor/autoload.php';
 (new Dotenv())->loadEnv(dirname(__DIR__).'/.env');
 
-if (empty($_ENV['OPENAI_API_KEY'])) {
-    echo 'Please set the OPENAI_API_KEY environment variable.'.PHP_EOL;
+if (empty($_ENV['ANTHROPIC_API_KEY'])) {
+    echo 'Please set the ANTHROPIC_API_KEY environment variable.'.PHP_EOL;
     exit(1);
 }
 
-$platform = PlatformFactory::create($_ENV['OPENAI_API_KEY']);
-$llm = new GPT(GPT::GPT_4O_MINI);
+$platform = PlatformFactory::create($_ENV['ANTHROPIC_API_KEY']);
+$llm = new Claude();
 
 $wikipedia = new Wikipedia(HttpClient::create());
 $toolbox = Toolbox::create($wikipedia);

src/Bridge/Anthropic/ModelHandler.php

@@ -61,12 +61,10 @@ public function request(Model $model, object|array|string $input, array $options
             $options['tool_choice'] = ['type' => 'auto'];
         }
 
-        $system = $input->getSystemMessage();
-        $body = array_merge($options, [
+        $body = [
             'model' => $model->getVersion(),
-            'system' => $system->content,
             'messages' => $input->withoutSystemMessage()->jsonSerialize(),
-        ]);
+        ];
 
         $body['messages'] = array_map(static function (MessageInterface $message) {
             if ($message instanceof ToolCallMessage) {
@@ -98,12 +96,16 @@ public function request(Model $model, object|array|string $input, array $options
             return $message;
         }, $body['messages']);
 
+        if ($system = $input->getSystemMessage()) {
+            $body['system'] = $system->content;
+        }
+
         return $this->httpClient->request('POST', 'https://api.anthropic.com/v1/messages', [
             'headers' => [
                 'x-api-key' => $this->apiKey,
                 'anthropic-version' => $this->version,
             ],
-            'json' => $body,
+            'json' => array_merge($options, $body),
         ]);
     }