Implement Functions Calling Example

config/services.yaml

@@ -22,6 +22,9 @@ services:
         $baseUrl: '%env(WEBHOOK_BASE_URL)%'
         $token: '%env(TELEGRAM_TOKEN)%'
 
+    App\SymfonyConBot\ToolBox\SerpApi\SerpApiFunction:
+        $apiKey: '%env(SERP_API_KEY)%'
+
     Probots\Pinecone\Client:
         $apiKey: '%env(PINECONE_API_KEY)%'
         $environment: '%env(PINECONE_ENVIRONMENT)%'

src/Command/DemoChatCommand.php

@@ -0,0 +1,36 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Command;
+
+use App\SymfonyConBot\Message\Message;
+use App\SymfonyConBot\Message\MessageBag;
+use App\SymfonyConBot\OpenAI\ChatModel;
+use Symfony\Component\Console\Attribute\AsCommand;
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Output\OutputInterface;
+use Symfony\Component\Console\Style\SymfonyStyle;
+
+#[AsCommand('app:demo:chat', description: 'Command for testing chat')]
+final class DemoChatCommand extends Command
+{
+    public function __construct(private readonly ChatModel $model)
+    {
+        parent::__construct();
+    }
+
+    protected function execute(InputInterface $input, OutputInterface $output): int
+    {
+        $io = new SymfonyStyle($input, $output);
+        $io->title('Demo Chat');
+
+        $prompt = $io->ask('What do you want to know?', 'What is the latest Symfony version?');
+        $response = $this->model->call(new MessageBag(Message::ofUser($prompt)));
+
+        $io->block($response['choices'][0]['message']['content']);
+
+        return 0;
+    }
+}

src/Command/DemoFunctionsCommand.php

@@ -0,0 +1,36 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Command;
+
+use App\SymfonyConBot\Message\Message;
+use App\SymfonyConBot\Message\MessageBag;
+use App\SymfonyConBot\OpenAI\FunctionChain;
+use Symfony\Component\Console\Attribute\AsCommand;
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Output\OutputInterface;
+use Symfony\Component\Console\Style\SymfonyStyle;
+
+#[AsCommand('app:demo:functions', description: 'Command for testing function calls')]
+final class DemoFunctionsCommand extends Command
+{
+    public function __construct(private readonly FunctionChain $chain)
+    {
+        parent::__construct();
+    }
+
+    protected function execute(InputInterface $input, OutputInterface $output): int
+    {
+        $io = new SymfonyStyle($input, $output);
+        $io->title('Demo Functions');
+
+        $prompt = $io->ask('What do you want to know?', 'What is the latest Symfony version?');
+        $response = $this->chain->call(new MessageBag(Message::ofUser($prompt)));
+
+        $io->writeln($response);
+
+        return 0;
+    }
+}

src/SymfonyConBot/OpenAI/FunctionChain.php

@@ -0,0 +1,40 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\SymfonyConBot\OpenAI;
+
+use App\SymfonyConBot\Message\Message;
+use App\SymfonyConBot\Message\MessageBag;
+use App\SymfonyConBot\ToolBox\FunctionRegistry;
+
+final readonly class FunctionChain
+{
+    public function __construct(
+        private ChatModel $model,
+        private FunctionRegistry $functionRegistry,
+    ) {
+    }
+
+    public function call(MessageBag $messages): string
+    {
+        $response = $this->model->call($messages, [
+            'functions' => $this->functionRegistry->getMap(),
+        ]);
+
+        while ('function_call' === $response['choices'][0]['finish_reason']) {
+            ['name' => $name, 'arguments' => $arguments] = $response['choices'][0]['message']['function_call'];
+            $result = $this->functionRegistry->execute($name, $arguments);
+
+            $messages[] = Message::ofAssistant(functionCall: [
+                'name' => $name,
+                'arguments' => $arguments,
+            ]);
+            $messages[] = Message::ofFunctionCall($name, $result);
+
+            $response = $this->model->call($messages);
+        }
+
+        return $response['choices'][0]['message']['content'];
+    }
+}

src/SymfonyConBot/ToolBox/FunctionInterface.php

@@ -0,0 +1,32 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\SymfonyConBot\ToolBox;
+
+use Symfony\Component\DependencyInjection\Attribute\AutoconfigureTag;
+
+/**
+ * @phpstan-type FunctionParameterDefinition array{
+ *     type: 'object',
+ *     properties: array<string, array{type: string, description: string}>,
+ *     required: list<string>,
+ * }
+ */
+#[AutoconfigureTag('llm_chain.function')]
+interface FunctionInterface
+{
+    public static function getName(): string;
+
+    public static function getDescription(): string;
+
+    /**
+     * @return FunctionParameterDefinition
+     */
+    public static function getParametersDefinition(): array;
+
+    /**
+     * @param array<string, mixed> $arguments
+     */
+    public function execute(array $arguments): string;
+}

src/SymfonyConBot/ToolBox/FunctionRegistry.php

@@ -0,0 +1,55 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\SymfonyConBot\ToolBox;
+
+use Symfony\Component\DependencyInjection\Attribute\TaggedIterator;
+
+/**
+ * @phpstan-import-type FunctionParameterDefinition from FunctionInterface
+ */
+final readonly class FunctionRegistry
+{
+    /**
+     * @var array<string, FunctionInterface>
+     */
+    private array $functions;
+
+    /**
+     * @param iterable<FunctionInterface> $functions
+     */
+    public function __construct(
+        #[TaggedIterator('llm_chain.function', defaultIndexMethod: 'getName')]
+        iterable $functions,
+    ) {
+        $this->functions = $functions instanceof \Traversable ? iterator_to_array($functions) : $functions;
+    }
+
+    /**
+     * @return list<array{
+     *     name: string,
+     *     description: string,
+     *     parameters: FunctionParameterDefinition,
+     * }>
+     */
+    public function getMap(): array
+    {
+        $functionsMap = [];
+
+        foreach ($this->functions as $function) {
+            $functionsMap[] = [
+                'name' => $function->getName(),
+                'description' => $function->getDescription(),
+                'parameters' => $function->getParametersDefinition(),
+            ];
+        }
+
+        return $functionsMap;
+    }
+
+    public function execute(string $name, string $arguments): string
+    {
+        return $this->functions[$name]->execute(json_decode($arguments, true));
+    }
+}

src/SymfonyConBot/ToolBox/SerpApi/SerpApiFunction.php

@@ -0,0 +1,70 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\SymfonyConBot\ToolBox\SerpApi;
+
+use App\SymfonyConBot\ToolBox\FunctionInterface;
+use Symfony\Contracts\HttpClient\HttpClientInterface;
+
+/**
+ * @phpstan-import-type FunctionParameterDefinition from FunctionInterface
+ */
+final readonly class SerpApiFunction implements FunctionInterface
+{
+    public function __construct(
+        private HttpClientInterface $httpClient,
+        private string $apiKey,
+    ) {
+    }
+
+    public static function getName(): string
+    {
+        return 'serpapi';
+    }
+
+    public static function getDescription(): string
+    {
+        return 'search for information on the internet';
+    }
+
+    /**
+     * @return FunctionParameterDefinition
+     */
+    public static function getParametersDefinition(): array
+    {
+        return [
+            'type' => 'object',
+            'properties' => [
+                'query' => [
+                    'type' => 'string',
+                    'description' => 'The search query to use',
+                ],
+            ],
+            'required' => ['query'],
+        ];
+    }
+
+    /**
+     * @param array{query: string} $arguments
+     */
+    public function execute(array $arguments): string
+    {
+        $response = $this->httpClient->request('GET', 'https://serpapi.com/search', [
+            'query' => [
+                'q' => $arguments['query'],
+                'api_key' => $this->apiKey,
+            ],
+        ]);
+
+        return sprintf('Results for "%s" are "%s".', $arguments['query'], $this->extractBestResponse($response->toArray()));
+    }
+
+    /**
+     * @param array<string, mixed> $results
+     */
+    private function extractBestResponse(array $results): string
+    {
+        return implode(PHP_EOL, array_map(fn ($story) => sprintf('%s: %s', $story['title'], $story['snippet']), $results['organic_results']));
+    }
+}