feat: add support for OpenRouter & Generic Models (#203)

* Added support for OpenRouter & Generic Models

* Fixed linting

---------

Co-authored-by: rglozman <[email protected]>

Author: rglozman

.env

@@ -21,6 +21,9 @@ AZURE_OPENAI_DEPLOYMENT=
 AZURE_OPENAI_VERSION=
 AZURE_OPENAI_KEY=
 
+# For using OpenRouter
+OPENROUTER_KEY=
+
 # For using SerpApi (tool)
 SERP_API_KEY=
 

README.md

@@ -63,6 +63,8 @@ $embeddings = new Embeddings();
   * [OpenAI's GPT](https://platform.openai.com/docs/models/overview) with [OpenAI](https://platform.openai.com/docs/overview) and [Azure](https://learn.microsoft.com/azure/ai-services/openai/concepts/models) as Platform
   * [Anthropic's Claude](https://www.anthropic.com/claude) with [Anthropic](https://www.anthropic.com/) as Platform
   * [Meta's Llama](https://www.llama.com/) with [Ollama](https://ollama.com/) and [Replicate](https://replicate.com/) as Platform
+  * [Google's Gemini](https://gemini.google.com/) with [OpenRouter](https://www.openrouter.com/) as Platform
+  * [DeepSeek's R1](https://www.deepseek.com/) with [OpenRouter](https://www.openrouter.com/) as Platform
 * Embeddings Models
   * [OpenAI's Text Embeddings](https://platform.openai.com/docs/guides/embeddings/embedding-models) with [OpenAI](https://platform.openai.com/docs/overview) and [Azure](https://learn.microsoft.com/azure/ai-services/openai/concepts/models) as Platform
   * [Voyage's Embeddings](https://docs.voyageai.com/docs/embeddings) with [Voyage](https://www.voyageai.com/) as Platform
@@ -125,6 +127,7 @@ $response = $chain->call($messages, [
 1. **OpenAI's o1**: [chat-o1-openai.php](examples/chat-o1-openai.php)
 1. **Meta's Llama with Ollama**: [chat-llama-ollama.php](examples/chat-llama-ollama.php)
 1. **Meta's Llama with Replicate**: [chat-llama-replicate.php](examples/chat-llama-replicate.php)
+1. **Google's Gemini with OpenRouter**: [chat-gemini-openrouter.php](examples/chat-gemini-openrouter.php)
 
 ### Tools
 

examples/chat-gemini-openrouter.php

@@ -0,0 +1,28 @@
+<?php
+
+use PhpLlm\LlmChain\Bridge\OpenRouter\GenericModel;
+use PhpLlm\LlmChain\Bridge\OpenRouter\PlatformFactory;
+use PhpLlm\LlmChain\Chain;
+use PhpLlm\LlmChain\Model\Message\Message;
+use PhpLlm\LlmChain\Model\Message\MessageBag;
+use Symfony\Component\Dotenv\Dotenv;
+
+require_once dirname(__DIR__).'/vendor/autoload.php';
+(new Dotenv())->loadEnv(dirname(__DIR__).'/.env');
+
+if (empty($_ENV['OPENROUTER_KEY'])) {
+    echo 'Please set the OPENROUTER_KEY environment variable.'.PHP_EOL;
+    exit(1);
+}
+
+$platform = PlatformFactory::create($_ENV['OPENROUTER_KEY']);
+$llm = new GenericModel('google/gemini-2.0-flash-thinking-exp:free');
+
+$chain = new Chain($platform, $llm);
+$messages = new MessageBag(
+    Message::forSystem('You are a helpful assistant.'),
+    Message::ofUser('Tina has one brother and one sister. How many sisters do Tina\'s siblings have?'),
+);
+$response = $chain->call($messages);
+
+echo $response->getContent().PHP_EOL;

src/Bridge/OpenRouter/Client.php

@@ -0,0 +1,62 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PhpLlm\LlmChain\Bridge\OpenRouter;
+
+use PhpLlm\LlmChain\Exception\RuntimeException;
+use PhpLlm\LlmChain\Model\Message\MessageBagInterface;
+use PhpLlm\LlmChain\Model\Model;
+use PhpLlm\LlmChain\Model\Response\ResponseInterface as LlmResponse;
+use PhpLlm\LlmChain\Model\Response\TextResponse;
+use PhpLlm\LlmChain\Platform\ModelClient;
+use PhpLlm\LlmChain\Platform\ResponseConverter;
+use Symfony\Component\HttpClient\EventSourceHttpClient;
+use Symfony\Contracts\HttpClient\HttpClientInterface;
+use Symfony\Contracts\HttpClient\ResponseInterface;
+use Webmozart\Assert\Assert;
+
+final readonly class Client implements ModelClient, ResponseConverter
+{
+    private EventSourceHttpClient $httpClient;
+
+    public function __construct(
+        HttpClientInterface $httpClient,
+        #[\SensitiveParameter] private string $apiKey,
+    ) {
+        $this->httpClient = $httpClient instanceof EventSourceHttpClient ? $httpClient : new EventSourceHttpClient($httpClient);
+        Assert::stringNotEmpty($apiKey, 'The API key must not be empty.');
+        Assert::startsWith($apiKey, 'sk-', 'The API key must start with "sk-".');
+    }
+
+    public function supports(Model $model, array|string|object $input): bool
+    {
+        return $input instanceof MessageBagInterface;
+    }
+
+    public function request(Model $model, object|array|string $input, array $options = []): ResponseInterface
+    {
+        return $this->httpClient->request('POST', 'https://openrouter.ai/api/v1/chat/completions', [
+            'auth_bearer' => $this->apiKey,
+            'json' => array_merge($options, [
+                'model' => $model->getVersion(),
+                'messages' => $input,
+            ]),
+        ]);
+    }
+
+    public function convert(ResponseInterface $response, array $options = []): LlmResponse
+    {
+        $data = $response->toArray();
+
+        if (!isset($data['choices'][0]['message'])) {
+            throw new RuntimeException('Response does not contain message');
+        }
+
+        if (!isset($data['choices'][0]['message']['content'])) {
+            throw new RuntimeException('Message does not contain content');
+        }
+
+        return new TextResponse($data['choices'][0]['message']['content']);
+    }
+}

src/Bridge/OpenRouter/GenericModel.php

@@ -0,0 +1,55 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PhpLlm\LlmChain\Bridge\OpenRouter;
+
+use PhpLlm\LlmChain\Bridge\Meta\Llama;
+use PhpLlm\LlmChain\Model\LanguageModel;
+
+final readonly class GenericModel implements LanguageModel
+{
+    /**
+     * @param array<string, mixed> $options
+     */
+    public function __construct(
+        private string $version = Llama::LLAMA_3_2_90B_VISION_INSTRUCT,
+        private array $options = [],
+    ) {
+    }
+
+    public function getVersion(): string
+    {
+        return $this->version;
+    }
+
+    public function getOptions(): array
+    {
+        return $this->options;
+    }
+
+    public function supportsAudioInput(): bool
+    {
+        return false; // it does, but implementation here is still open.
+    }
+
+    public function supportsImageInput(): bool
+    {
+        return false; // it does, but implementation here is still open.
+    }
+
+    public function supportsStreaming(): bool
+    {
+        return false; // it does, but implementation here is still open.
+    }
+
+    public function supportsToolCalling(): bool
+    {
+        return false; // it does, but implementation here is still open.
+    }
+
+    public function supportsStructuredOutput(): bool
+    {
+        return false; // it does, but implementation here is still open.
+    }
+}

src/Bridge/OpenRouter/PlatformFactory.php

@@ -0,0 +1,23 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PhpLlm\LlmChain\Bridge\OpenRouter;
+
+use PhpLlm\LlmChain\Platform;
+use Symfony\Component\HttpClient\EventSourceHttpClient;
+use Symfony\Contracts\HttpClient\HttpClientInterface;
+
+final class PlatformFactory
+{
+    public static function create(
+        #[\SensitiveParameter]
+        string $apiKey,
+        ?HttpClientInterface $httpClient = null,
+    ): Platform {
+        $httpClient = $httpClient instanceof EventSourceHttpClient ? $httpClient : new EventSourceHttpClient($httpClient);
+        $handler = new Client($httpClient, $apiKey);
+
+        return new Platform([$handler], [$handler]);
+    }
+}