feat: add inline tool definition and chain in chain 🤯 (#75)

Author: chr-hertel

README.md

@@ -50,7 +50,20 @@ llm_chain:
             system_prompt: 'You are a helpful assistant that can answer questions.' # The default system prompt of the chain
             include_tools: true # Include tool definitions at the end of the system prompt 
             tools:
-                - 'PhpLlm\LlmChain\Chain\ToolBox\Tool\SimilaritySearch'
+                # Referencing a service with #[AsTool] attribute
+                - 'PhpLlm\LlmChain\Chain\Toolbox\Tool\SimilaritySearch'
+                
+                # Referencing a service without #[AsTool] attribute
+                - service: 'App\Chain\Tool\CompanyName'
+                  name: 'company_name'
+                  description: 'Provides the name of your company'
+                  method: 'foo' # Optional with default value '__invoke'
+                
+                # Referencing a chain => chain in chain 🤯
+                - service: 'llm_chain.chain.research'
+                  name: 'wikipedia_research'
+                  description: 'Can research on Wikipedia'
+                  is_chain: true
         research:
             platform: 'llm_chain.platform.anthropic'
             model:

src/DependencyInjection/Configuration.php

@@ -98,7 +98,21 @@ public function getConfigTreeBuilder(): TreeBuilder
                                 ->children()
                                     ->booleanNode('enabled')->defaultTrue()->end()
                                     ->arrayNode('services')
-                                        ->scalarPrototype()->end()
+                                        ->arrayPrototype()
+                                            ->children()
+                                                ->scalarNode('service')->isRequired()->end()
+                                                ->scalarNode('name')->end()
+                                                ->scalarNode('description')->end()
+                                                ->scalarNode('method')->end()
+                                                ->booleanNode('is_chain')->defaultFalse()->end()
+                                            ->end()
+                                            ->beforeNormalization()
+                                                ->ifString()
+                                                ->then(function (string $v) {
+                                                    return ['service' => $v];
+                                                })
+                                            ->end()
+                                        ->end()
                                     ->end()
                                 ->end()
                             ->end()

src/DependencyInjection/LlmChainExtension.php

@@ -26,6 +26,10 @@
 use PhpLlm\LlmChain\Chain\Toolbox\Attribute\AsTool;
 use PhpLlm\LlmChain\Chain\Toolbox\ChainProcessor as ToolProcessor;
 use PhpLlm\LlmChain\Chain\Toolbox\FaultTolerantToolbox;
+use PhpLlm\LlmChain\Chain\Toolbox\MetadataFactory\ChainFactory;
+use PhpLlm\LlmChain\Chain\Toolbox\MetadataFactory\MemoryFactory;
+use PhpLlm\LlmChain\Chain\Toolbox\MetadataFactory\ReflectionFactory;
+use PhpLlm\LlmChain\Chain\Toolbox\Tool\Chain as ChainTool;
 use PhpLlm\LlmChain\ChainInterface;
 use PhpLlm\LlmChain\Embedder;
 use PhpLlm\LlmChain\Model\EmbeddingsModel;
@@ -249,9 +253,30 @@ private function processChainConfig(string $name, array $config, ContainerBuilde
         if ($config['tools']['enabled']) {
             // Create specific toolbox and process if tools are explicitly defined
             if (0 !== count($config['tools']['services'])) {
-                $tools = array_map(static fn (string $tool) => new Reference($tool), $config['tools']['services']);
+                $memoryFactoryDefinition = new Definition(MemoryFactory::class);
+                $container->setDefinition('llm_chain.toolbox.'.$name.'.memory_factory', $memoryFactoryDefinition);
+                $chainFactoryDefinition = new Definition(ChainFactory::class, [
+                    '$factories' => [new Reference('llm_chain.toolbox.'.$name.'.memory_factory'), new Reference(ReflectionFactory::class)],
+                ]);
+                $container->setDefinition('llm_chain.toolbox.'.$name.'.chain_factory', $chainFactoryDefinition);
+
+                $tools = [];
+                foreach ($config['tools']['services'] as $tool) {
+                    $reference = new Reference($tool['service']);
+                    // We use the memory factory in case method, description and name are set
+                    if (isset($tool['name'], $tool['description'])) {
+                        if ($tool['is_chain']) {
+                            $chainWrapperDefinition = new Definition(ChainTool::class, ['$chain' => $reference]);
+                            $container->setDefinition('llm_chain.toolbox.'.$name.'.chain_wrapper.'.$tool['name'], $chainWrapperDefinition);
+                            $reference = new Reference('llm_chain.toolbox.'.$name.'.chain_wrapper.'.$tool['name']);
+                        }
+                        $memoryFactoryDefinition->addMethodCall('addTool', [$reference, $tool['name'], $tool['description'], $tool['method'] ?? '__invoke']);
+                    }
+                    $tools[] = $reference;
+                }
 
                 $toolboxDefinition = (new ChildDefinition('llm_chain.toolbox.abstract'))
+                    ->replaceArgument('$metadataFactory', new Reference('llm_chain.toolbox.'.$name.'.chain_factory'))
                     ->replaceArgument('$tools', $tools);
                 $container->setDefinition('llm_chain.toolbox.'.$name, $toolboxDefinition);
 

src/Resources/config/services.php

@@ -33,6 +33,7 @@
             ->autowire()
             ->abstract()
             ->args([
+                '$metadataFactory' => service(MetadataFactory::class),
                 '$tools' => abstract_arg('Collection of tools'),
             ])
         ->set(Toolbox::class)