[AIBundle] Simplify agent-as-tool configuration

Author: valtzu

demo/config/packages/ai.yaml

@@ -46,10 +46,9 @@ ai:
             system_prompt: 'You are a friendly chatbot that likes to have a conversation with users and asks them some questions.'
             tools:
                 # Agent in agent 🤯
-                - service: 'ai.agent.blog'
+                - agent: 'blog'
                   name: 'symfony_blog'
                   description: 'Can answer questions based on the Symfony blog.'
-                  is_agent: true
     store:
         chroma_db:
             symfonycon:

src/ai-bundle/config/options.php

@@ -117,18 +117,22 @@
                                 ->arrayNode('services')
                                     ->arrayPrototype()
                                         ->children()
-                                            ->scalarNode('service')->isRequired()->end()
+                                            ->scalarNode('service')->cannotBeEmpty()->end()
+                                            ->scalarNode('agent')->cannotBeEmpty()->end()
                                             ->scalarNode('name')->end()
                                             ->scalarNode('description')->end()
                                             ->scalarNode('method')->end()
-                                            ->booleanNode('is_agent')->defaultFalse()->end()
                                         ->end()
                                         ->beforeNormalization()
                                             ->ifString()
                                             ->then(function (string $v) {
                                                 return ['service' => $v];
                                             })
                                         ->end()
+                                        ->validate()
+                                            ->ifTrue(static fn ($v) => !(empty($v['agent']) xor empty($v['service'])))
+                                            ->thenInvalid('Either "agent" or "service" must be configured, and never both.')
+                                        ->end()
                                     ->end()
                                 ->end()
                             ->end()

src/ai-bundle/doc/index.rst

@@ -72,10 +72,9 @@ Configuration
                       method: 'foo' # Optional with default value '__invoke'
 
                     # Referencing a agent => agent in agent 🤯
-                    - service: 'ai.agent.research'
+                    - agent: 'research'
                       name: 'wikipedia_research'
                       description: 'Can research on Wikipedia'
-                      is_agent: true
             research:
                 platform: 'ai.platform.anthropic'
                 model:

src/ai-bundle/src/AIBundle.php

@@ -333,10 +333,14 @@ private function processAgentConfig(string $name, array $config, ContainerBuilde
 
                 $tools = [];
                 foreach ($config['tools']['services'] as $tool) {
+                    if (isset($tool['agent'])) {
+                        $tool['name'] ??= $tool['agent'];
+                        $tool['service'] = \sprintf('ai.agent.%s', $tool['agent']);
+                    }
                     $reference = new Reference($tool['service']);
                     // We use the memory factory in case method, description and name are set
                     if (isset($tool['name'], $tool['description'])) {
-                        if ($tool['is_agent']) {
+                        if (isset($tool['agent'])) {
                             $agentWrapperDefinition = new Definition(AgentTool::class, [$reference]);
                             $container->setDefinition('ai.toolbox.'.$name.'.agent_wrapper.'.$tool['name'], $agentWrapperDefinition);
                             $reference = new Reference('ai.toolbox.'.$name.'.agent_wrapper.'.$tool['name']);

src/ai-bundle/tests/DependencyInjection/AIBundleTest.php

@@ -13,26 +13,72 @@
 
 use PHPUnit\Framework\Attributes\CoversClass;
 use PHPUnit\Framework\Attributes\DoesNotPerformAssertions;
+use PHPUnit\Framework\Attributes\Test;
 use PHPUnit\Framework\Attributes\UsesClass;
 use PHPUnit\Framework\TestCase;
 use Symfony\AI\AIBundle\AIBundle;
+use Symfony\Component\Config\Definition\Exception\InvalidConfigurationException;
 use Symfony\Component\DependencyInjection\ContainerBuilder;
 
 #[CoversClass(AIBundle::class)]
 #[UsesClass(ContainerBuilder::class)]
 class AIBundleTest extends TestCase
 {
     #[DoesNotPerformAssertions]
-    public function testExtensionLoad(): void
+    #[Test]
+    public function extensionLoadDoesNotThrow(): void
+    {
+        $this->buildContainer($this->getFullConfig());
+    }
+
+    #[Test]
+    public function agentsCanBeRegisteredAsTools(): void
+    {
+        $container = $this->buildContainer([
+            'ai' => [
+                'agent' => [
+                    'main_agent' => [
+                        'model' => ['class' => 'Symfony\AI\Platform\Bridge\OpenAI\GPT'],
+                        'tools' => [
+                            ['agent' => 'another_agent', 'description' => 'Agent tool with implicit name'],
+                            ['agent' => 'another_agent', 'name' => 'another_agent_instance', 'description' => 'Agent tool with explicit name'],
+                        ],
+                    ],
+                ],
+            ],
+        ]);
+
+        $this->assertTrue($container->hasDefinition('ai.toolbox.main_agent.agent_wrapper.another_agent'));
+        $this->assertTrue($container->hasDefinition('ai.toolbox.main_agent.agent_wrapper.another_agent_instance'));
+    }
+
+    #[Test]
+    public function agentsAsToolsCannotDefineService(): void
+    {
+        $this->expectException(InvalidConfigurationException::class);
+        $this->buildContainer([
+            'ai' => [
+                'agent' => [
+                    'main_agent' => [
+                        'model' => ['class' => 'Symfony\AI\Platform\Bridge\OpenAI\GPT'],
+                        'tools' => [['agent' => 'another_agent', 'service' => 'foo_bar', 'description' => 'Agent with service']],
+                    ],
+                ],
+            ],
+        ]);
+    }
+
+    private function buildContainer(array $configuration): ContainerBuilder
     {
         $container = new ContainerBuilder();
         $container->setParameter('kernel.debug', true);
         $container->setParameter('kernel.environment', 'dev');
         $container->setParameter('kernel.build_dir', 'public');
+
         $extension = (new AIBundle())->getContainerExtension();
+        $extension->load($configuration, $container);
 
-        $configs = $this->getFullConfig();
-        $extension->load($configs, $container);
+        return $container;
     }
 
     /**