diff --git a/src/platform/tests/Bridge/OpenAi/Embeddings/ModelClientTest.php b/src/platform/tests/Bridge/OpenAi/Embeddings/ModelClientTest.php
new file mode 100644
index 000000000..33c4924ef
--- /dev/null
+++ b/src/platform/tests/Bridge/OpenAi/Embeddings/ModelClientTest.php
@@ -0,0 +1,114 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\AI\Platform\Tests\Bridge\OpenAi\Embeddings;
+
+use PHPUnit\Framework\Attributes\CoversClass;
+use PHPUnit\Framework\Attributes\Small;
+use PHPUnit\Framework\Attributes\TestWith;
+use PHPUnit\Framework\Attributes\UsesClass;
+use PHPUnit\Framework\TestCase;
+use Symfony\AI\Platform\Bridge\OpenAi\Embeddings;
+use Symfony\AI\Platform\Bridge\OpenAi\Embeddings\ModelClient;
+use Symfony\AI\Platform\Exception\InvalidArgumentException;
+use Symfony\Component\HttpClient\MockHttpClient;
+use Symfony\Component\HttpClient\Response\MockResponse;
+use Symfony\Contracts\HttpClient\ResponseInterface as HttpResponse;
+
+/**
+ * @author Oskar Stark <oskarstark@googlemail.com>
+ */
+#[CoversClass(ModelClient::class)]
+#[UsesClass(Embeddings::class)]
+#[Small]
+final class ModelClientTest extends TestCase
+{
+    public function testItThrowsExceptionWhenApiKeyIsEmpty()
+    {
+        $this->expectException(InvalidArgumentException::class);
+        $this->expectExceptionMessage('The API key must not be empty.');
+
+        new ModelClient(new MockHttpClient(), '');
+    }
+
+    #[TestWith(['api-key-without-prefix'])]
+    #[TestWith(['pk-api-key'])]
+    #[TestWith(['SK-api-key'])]
+    #[TestWith(['skapikey'])]
+    #[TestWith(['sk api-key'])]
+    #[TestWith(['sk'])]
+    public function testItThrowsExceptionWhenApiKeyDoesNotStartWithSk(string $invalidApiKey)
+    {
+        $this->expectException(InvalidArgumentException::class);
+        $this->expectExceptionMessage('The API key must start with "sk-".');
+
+        new ModelClient(new MockHttpClient(), $invalidApiKey);
+    }
+
+    public function testItAcceptsValidApiKey()
+    {
+        $modelClient = new ModelClient(new MockHttpClient(), 'sk-valid-api-key');
+
+        $this->assertInstanceOf(ModelClient::class, $modelClient);
+    }
+
+    public function testItIsSupportingTheCorrectModel()
+    {
+        $modelClient = new ModelClient(new MockHttpClient(), 'sk-api-key');
+
+        $this->assertTrue($modelClient->supports(new Embeddings()));
+    }
+
+    public function testItIsExecutingTheCorrectRequest()
+    {
+        $resultCallback = static function (string $method, string $url, array $options): HttpResponse {
+            self::assertSame('POST', $method);
+            self::assertSame('https://api.openai.com/v1/embeddings', $url);
+            self::assertSame('Authorization: Bearer sk-api-key', $options['normalized_headers']['authorization'][0]);
+            self::assertSame('{"model":"text-embedding-3-small","input":"test text"}', $options['body']);
+
+            return new MockResponse();
+        };
+        $httpClient = new MockHttpClient([$resultCallback]);
+        $modelClient = new ModelClient($httpClient, 'sk-api-key');
+        $modelClient->request(new Embeddings(), 'test text', []);
+    }
+
+    public function testItIsExecutingTheCorrectRequestWithCustomOptions()
+    {
+        $resultCallback = static function (string $method, string $url, array $options): HttpResponse {
+            self::assertSame('POST', $method);
+            self::assertSame('https://api.openai.com/v1/embeddings', $url);
+            self::assertSame('Authorization: Bearer sk-api-key', $options['normalized_headers']['authorization'][0]);
+            self::assertSame('{"dimensions":256,"model":"text-embedding-3-large","input":"test text"}', $options['body']);
+
+            return new MockResponse();
+        };
+        $httpClient = new MockHttpClient([$resultCallback]);
+        $modelClient = new ModelClient($httpClient, 'sk-api-key');
+        $modelClient->request(new Embeddings(Embeddings::TEXT_3_LARGE), 'test text', ['dimensions' => 256]);
+    }
+
+    public function testItIsExecutingTheCorrectRequestWithArrayInput()
+    {
+        $resultCallback = static function (string $method, string $url, array $options): HttpResponse {
+            self::assertSame('POST', $method);
+            self::assertSame('https://api.openai.com/v1/embeddings', $url);
+            self::assertSame('Authorization: Bearer sk-api-key', $options['normalized_headers']['authorization'][0]);
+            self::assertSame('{"model":"text-embedding-3-small","input":["text1","text2","text3"]}', $options['body']);
+
+            return new MockResponse();
+        };
+        $httpClient = new MockHttpClient([$resultCallback]);
+        $modelClient = new ModelClient($httpClient, 'sk-api-key');
+        $modelClient->request(new Embeddings(), ['text1', 'text2', 'text3'], []);
+    }
+}
diff --git a/src/platform/tests/Bridge/OpenAi/EmbeddingsTest.php b/src/platform/tests/Bridge/OpenAi/EmbeddingsTest.php
new file mode 100644
index 000000000..9bc6e5a02
--- /dev/null
+++ b/src/platform/tests/Bridge/OpenAi/EmbeddingsTest.php
@@ -0,0 +1,48 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\AI\Platform\Tests\Bridge\OpenAi;
+
+use PHPUnit\Framework\Attributes\CoversClass;
+use PHPUnit\Framework\Attributes\Small;
+use PHPUnit\Framework\TestCase;
+use Symfony\AI\Platform\Bridge\OpenAi\Embeddings;
+
+/**
+ * @author Oskar Stark <oskarstark@googlemail.com>
+ */
+#[CoversClass(Embeddings::class)]
+#[Small]
+final class EmbeddingsTest extends TestCase
+{
+    public function testItCreatesEmbeddingsWithDefaultSettings()
+    {
+        $embeddings = new Embeddings();
+
+        $this->assertSame(Embeddings::TEXT_3_SMALL, $embeddings->getName());
+        $this->assertSame([], $embeddings->getOptions());
+    }
+
+    public function testItCreatesEmbeddingsWithCustomSettings()
+    {
+        $embeddings = new Embeddings(Embeddings::TEXT_3_LARGE, ['dimensions' => 256]);
+
+        $this->assertSame(Embeddings::TEXT_3_LARGE, $embeddings->getName());
+        $this->assertSame(['dimensions' => 256], $embeddings->getOptions());
+    }
+
+    public function testItCreatesEmbeddingsWithAdaModel()
+    {
+        $embeddings = new Embeddings(Embeddings::TEXT_ADA_002);
+
+        $this->assertSame(Embeddings::TEXT_ADA_002, $embeddings->getName());
+    }
+}
diff --git a/src/platform/tests/Bridge/OpenAi/Gpt/ModelClientTest.php b/src/platform/tests/Bridge/OpenAi/Gpt/ModelClientTest.php
new file mode 100644
index 000000000..f72581adf
--- /dev/null
+++ b/src/platform/tests/Bridge/OpenAi/Gpt/ModelClientTest.php
@@ -0,0 +1,116 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\AI\Platform\Tests\Bridge\OpenAi\Gpt;
+
+use PHPUnit\Framework\Attributes\CoversClass;
+use PHPUnit\Framework\Attributes\Small;
+use PHPUnit\Framework\Attributes\TestWith;
+use PHPUnit\Framework\Attributes\UsesClass;
+use PHPUnit\Framework\TestCase;
+use Symfony\AI\Platform\Bridge\OpenAi\Gpt;
+use Symfony\AI\Platform\Bridge\OpenAi\Gpt\ModelClient;
+use Symfony\AI\Platform\Exception\InvalidArgumentException;
+use Symfony\Component\HttpClient\EventSourceHttpClient;
+use Symfony\Component\HttpClient\MockHttpClient;
+use Symfony\Component\HttpClient\Response\MockResponse;
+use Symfony\Contracts\HttpClient\ResponseInterface as HttpResponse;
+
+/**
+ * @author Oskar Stark <oskarstark@googlemail.com>
+ */
+#[CoversClass(ModelClient::class)]
+#[UsesClass(Gpt::class)]
+#[Small]
+final class ModelClientTest extends TestCase
+{
+    public function testItThrowsExceptionWhenApiKeyIsEmpty()
+    {
+        $this->expectException(InvalidArgumentException::class);
+        $this->expectExceptionMessage('The API key must not be empty.');
+
+        new ModelClient(new MockHttpClient(), '');
+    }
+
+    #[TestWith(['api-key-without-prefix'])]
+    #[TestWith(['pk-api-key'])]
+    #[TestWith(['SK-api-key'])]
+    #[TestWith(['skapikey'])]
+    #[TestWith(['sk api-key'])]
+    #[TestWith(['sk'])]
+    public function testItThrowsExceptionWhenApiKeyDoesNotStartWithSk(string $invalidApiKey)
+    {
+        $this->expectException(InvalidArgumentException::class);
+        $this->expectExceptionMessage('The API key must start with "sk-".');
+
+        new ModelClient(new MockHttpClient(), $invalidApiKey);
+    }
+
+    public function testItAcceptsValidApiKey()
+    {
+        $modelClient = new ModelClient(new MockHttpClient(), 'sk-valid-api-key');
+
+        $this->assertInstanceOf(ModelClient::class, $modelClient);
+    }
+
+    public function testItWrapsHttpClientInEventSourceHttpClient()
+    {
+        $httpClient = new MockHttpClient();
+        $modelClient = new ModelClient($httpClient, 'sk-valid-api-key');
+
+        $this->assertInstanceOf(ModelClient::class, $modelClient);
+    }
+
+    public function testItAcceptsEventSourceHttpClientDirectly()
+    {
+        $httpClient = new EventSourceHttpClient(new MockHttpClient());
+        $modelClient = new ModelClient($httpClient, 'sk-valid-api-key');
+
+        $this->assertInstanceOf(ModelClient::class, $modelClient);
+    }
+
+    public function testItIsSupportingTheCorrectModel()
+    {
+        $modelClient = new ModelClient(new MockHttpClient(), 'sk-api-key');
+
+        $this->assertTrue($modelClient->supports(new Gpt()));
+    }
+
+    public function testItIsExecutingTheCorrectRequest()
+    {
+        $resultCallback = static function (string $method, string $url, array $options): HttpResponse {
+            self::assertSame('POST', $method);
+            self::assertSame('https://api.openai.com/v1/chat/completions', $url);
+            self::assertSame('Authorization: Bearer sk-api-key', $options['normalized_headers']['authorization'][0]);
+            self::assertSame('{"temperature":1,"model":"gpt-4o","messages":[{"role":"user","content":"test message"}]}', $options['body']);
+
+            return new MockResponse();
+        };
+        $httpClient = new MockHttpClient([$resultCallback]);
+        $modelClient = new ModelClient($httpClient, 'sk-api-key');
+        $modelClient->request(new Gpt(), ['model' => 'gpt-4o', 'messages' => [['role' => 'user', 'content' => 'test message']]], ['temperature' => 1]);
+    }
+
+    public function testItIsExecutingTheCorrectRequestWithArrayPayload()
+    {
+        $resultCallback = static function (string $method, string $url, array $options): HttpResponse {
+            self::assertSame('POST', $method);
+            self::assertSame('https://api.openai.com/v1/chat/completions', $url);
+            self::assertSame('Authorization: Bearer sk-api-key', $options['normalized_headers']['authorization'][0]);
+            self::assertSame('{"temperature":0.7,"model":"gpt-4o","messages":[{"role":"user","content":"Hello"}]}', $options['body']);
+
+            return new MockResponse();
+        };
+        $httpClient = new MockHttpClient([$resultCallback]);
+        $modelClient = new ModelClient($httpClient, 'sk-api-key');
+        $modelClient->request(new Gpt(), ['model' => 'gpt-4o', 'messages' => [['role' => 'user', 'content' => 'Hello']]], ['temperature' => 0.7]);
+    }
+}
diff --git a/src/platform/tests/Bridge/OpenAi/GptTest.php b/src/platform/tests/Bridge/OpenAi/GptTest.php
new file mode 100644
index 000000000..4caeb6f11
--- /dev/null
+++ b/src/platform/tests/Bridge/OpenAi/GptTest.php
@@ -0,0 +1,41 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\AI\Platform\Tests\Bridge\OpenAi;
+
+use PHPUnit\Framework\Attributes\CoversClass;
+use PHPUnit\Framework\Attributes\Small;
+use PHPUnit\Framework\TestCase;
+use Symfony\AI\Platform\Bridge\OpenAi\Gpt;
+
+/**
+ * @author Oskar Stark <oskarstark@googlemail.com>
+ */
+#[CoversClass(Gpt::class)]
+#[Small]
+final class GptTest extends TestCase
+{
+    public function testItCreatesGptWithDefaultSettings()
+    {
+        $gpt = new Gpt();
+
+        $this->assertSame(Gpt::GPT_4O, $gpt->getName());
+        $this->assertSame(['temperature' => 1.0], $gpt->getOptions());
+    }
+
+    public function testItCreatesGptWithCustomSettings()
+    {
+        $gpt = new Gpt(Gpt::GPT_4_TURBO, ['temperature' => 0.5, 'max_tokens' => 1000]);
+
+        $this->assertSame(Gpt::GPT_4_TURBO, $gpt->getName());
+        $this->assertSame(['temperature' => 0.5, 'max_tokens' => 1000], $gpt->getOptions());
+    }
+}
diff --git a/src/platform/tests/Bridge/OpenAi/PlatformFactoryTest.php b/src/platform/tests/Bridge/OpenAi/PlatformFactoryTest.php
new file mode 100644
index 000000000..87eae9b51
--- /dev/null
+++ b/src/platform/tests/Bridge/OpenAi/PlatformFactoryTest.php
@@ -0,0 +1,51 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\AI\Platform\Tests\Bridge\OpenAi;
+
+use PHPUnit\Framework\Attributes\CoversClass;
+use PHPUnit\Framework\Attributes\Small;
+use PHPUnit\Framework\TestCase;
+use Symfony\AI\Platform\Bridge\OpenAi\PlatformFactory;
+use Symfony\AI\Platform\Platform;
+use Symfony\Component\HttpClient\EventSourceHttpClient;
+use Symfony\Component\HttpClient\MockHttpClient;
+
+/**
+ * @author Oskar Stark <oskarstark@googlemail.com>
+ */
+#[CoversClass(PlatformFactory::class)]
+#[Small]
+final class PlatformFactoryTest extends TestCase
+{
+    public function testItCreatesPlatformWithDefaultSettings()
+    {
+        $platform = PlatformFactory::create('sk-test-api-key');
+
+        $this->assertInstanceOf(Platform::class, $platform);
+    }
+
+    public function testItCreatesPlatformWithCustomHttpClient()
+    {
+        $httpClient = new MockHttpClient();
+        $platform = PlatformFactory::create('sk-test-api-key', $httpClient);
+
+        $this->assertInstanceOf(Platform::class, $platform);
+    }
+
+    public function testItCreatesPlatformWithEventSourceHttpClient()
+    {
+        $httpClient = new EventSourceHttpClient(new MockHttpClient());
+        $platform = PlatformFactory::create('sk-test-api-key', $httpClient);
+
+        $this->assertInstanceOf(Platform::class, $platform);
+    }
+}
diff --git a/src/platform/tests/Bridge/OpenAi/WhisperTest.php b/src/platform/tests/Bridge/OpenAi/WhisperTest.php
new file mode 100644
index 000000000..428efe057
--- /dev/null
+++ b/src/platform/tests/Bridge/OpenAi/WhisperTest.php
@@ -0,0 +1,41 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\AI\Platform\Tests\Bridge\OpenAi;
+
+use PHPUnit\Framework\Attributes\CoversClass;
+use PHPUnit\Framework\Attributes\Small;
+use PHPUnit\Framework\TestCase;
+use Symfony\AI\Platform\Bridge\OpenAi\Whisper;
+
+/**
+ * @author Oskar Stark <oskarstark@googlemail.com>
+ */
+#[CoversClass(Whisper::class)]
+#[Small]
+final class WhisperTest extends TestCase
+{
+    public function testItCreatesWhisperWithDefaultSettings()
+    {
+        $whisper = new Whisper();
+
+        $this->assertSame(Whisper::WHISPER_1, $whisper->getName());
+        $this->assertSame([], $whisper->getOptions());
+    }
+
+    public function testItCreatesWhisperWithCustomSettings()
+    {
+        $whisper = new Whisper(Whisper::WHISPER_1, ['language' => 'en', 'response_format' => 'json']);
+
+        $this->assertSame(Whisper::WHISPER_1, $whisper->getName());
+        $this->assertSame(['language' => 'en', 'response_format' => 'json'], $whisper->getOptions());
+    }
+}