Google Agent Platform PHP SDK

A lightweight, dependency-free PHP wrapper for the Google Agent Platform (formerly known as Vertex AI). Google rebranded Vertex AI to "Agent Platform" to reflect its expanded focus on agentic AI workflows. All existing Vertex AI endpoints remain fully compatible.

API Keys: Manage your API keys at https://console.cloud.google.com/agent-platform/studio/settings/api-keys

Installation

composer require fabianternis/google-agent-platform-php

Requires PHP 8.1+, ext-curl, ext-json, ext-fileinfo.

Quick Start

require 'vendor/autoload.php';

use GoogleAgentPlatform\Client;

// Express Mode — API key
$client = new Client(['api_key' => 'YOUR_API_KEY']);

// Google Cloud Mode — OAuth token (required for Claude, Veo, Imagen, File API)
$client = new Client([
    'project_id'   => 'your-gcp-project-id',
    'access_token' => 'YOUR_ACCESS_TOKEN',
    'location'     => 'us-central1',
]);

Tip: Run gcloud auth application-default print-access-token locally to get a token.

Architecture

As of v0.5.0 the SDK uses a resource-based structure. Each capability lives in its own class, accessible as a property on Client. The legacy flat methods are still fully supported.

src/
├── Client.php                  ← main entry point (facade)
├── Http/
│   └── HttpClient.php          ← all cURL logic
├── Resources/
│   ├── TextResource.php        ← Gemini text generation
│   ├── ImageResource.php       ← Imagen image generation
│   ├── AudioResource.php       ← Text-to-Speech
│   ├── VideoResource.php       ← Veo video generation
│   ├── ClaudeResource.php      ← Anthropic Claude
│   └── FileResource.php        ← local file embed + File API upload
└── Support/
    └── MimeTypes.php           ← MIME detection and extension mapping

Resource API (recommended)

$client->text->generate([...]);
$client->images->generate('A red fox in the snow');
$client->audio->synthesize('Hello world');
$client->video->generate('A timelapse of a blooming flower');
$client->claude->messages([...]);
$client->files->withFile('/tmp/photo.jpg', 'What is in this image?');
$client->files->uploadFile('/tmp/large-video.mp4');

Legacy flat API (fully backward-compatible)

$client->generateContent([...]);
$client->generateImage('A red fox...');
$client->synthesizeSpeech('Hello world');
$client->generateVideo('A timelapse...');
$client->claudeMessages([...]);

Sending Files to Models

Two strategies depending on file size and reuse needs.

Strategy 1 — inlineData (local file, < ~20 MB)

Reads the file from disk, base64-encodes it, and embeds it directly in the request. Best for images, short audio clips, and small PDFs.

// Single file
$contents = $client->files->withFile(
    filePath: '/tmp/photo.jpg',
    text:     'What is in this image?'
);
$response = $client->generateContent($contents);
echo $response['candidates'][0]['content']['parts'][0]['text'];

// Multiple files in one request
$contents = $client->files->withFiles(
    files: [
        '/tmp/chart.png',
        ['path' => '/tmp/report.pdf', 'mimeType' => 'application/pdf'],
    ],
    text: 'Summarize the report and explain the chart.'
);
$response = $client->generateContent($contents);

MIME type is auto-detected via finfo (magic bytes). You can override it:

$contents = $client->files->withFile('/tmp/data.bin', 'Analyze this.', 'application/octet-stream');

Strategy 2 — File API upload (any size, reusable for 48 h)

Uploads the file to Google's File API via a resumable upload. Returns a URI you can reference in any subsequent request. Best for large files (> 20 MB), videos, and files used across multiple requests.

// Step 1: Upload once
$file = $client->files->uploadFile('/tmp/large-video.mp4');
// $file['uri']      → 'https://generativelanguage.googleapis.com/v1beta/files/abc123'
// $file['mimeType'] → 'video/mp4'
// $file['name']     → 'files/abc123'

// Step 2: Reference in any request
$contents = $client->files->fromUri(
    fileUri:  $file['uri'],
    mimeType: $file['mimeType'],
    text:     'Summarize this video.'
);
$response = $client->generateContent($contents);

// Or build the fileData part manually (GCS URI also works)
$response = $client->generateContent([[
    'role'  => 'user',
    'parts' => [
        ['fileData' => ['mimeType' => 'video/mp4', 'fileUri' => $file['uri']]],
        ['text'     => 'What happens in this video?'],
    ],
]]);

// List and inspect uploaded files
$list = $client->files->listFiles(pageSize: 20);
$meta = $client->files->getFile('files/abc123');

Text Generation — Gemini

$response = $client->text->generate([
    ['role' => 'user', 'parts' => [['text' => 'How does AI work?']]]
]);
echo $response['candidates'][0]['content']['parts'][0]['text'];

// Specific model
$response = $client->text->generate($contents, 'gemini-3.1-pro-preview');

// Streaming
$response = $client->text->stream($contents, 'gemini-3.1-pro-preview');

Image Generation — Imagen 3

Available Models

Model ID	Notes
`imagen-3.0-generate-001`	Highest quality (default)
`imagen-3.0-fast-generate-001`	Faster, lower cost

$client = new Client([
    'project_id'   => 'your-gcp-project-id',
    'access_token' => 'YOUR_ACCESS_TOKEN',
    'location'     => 'us-central1',
]);

// Generate and save to disk
$images = $client->images->generate(
    prompt:      'A photorealistic red fox sitting in a snowy forest at dusk.',
    sampleCount: 2,
    aspectRatio: '16:9',
    outputDir:   '/tmp/images'
);
foreach ($images as $img) {
    echo $img['savedPath'] . PHP_EOL;
}

// Return as base64 (no file saving)
$images = $client->images->generate('An oil painting of a lighthouse at sunset.');
$base64 = $images[0]['base64'];
// <img src="data:image/png;base64,{$base64}">

// Advanced parameters
$images = $client->images->generate(
    prompt:           'A futuristic city skyline at night.',
    aspectRatio:      '9:16',
    outputDir:        '/tmp/images',
    additionalParams: [
        'negativePrompt'   => 'blurry, low quality, cartoon',
        'personGeneration' => 'dont_allow',
    ]
);

Text-to-Speech (TTS)

Available Models

Model ID	Description
`gemini-3.1-flash-tts-preview`	Default — low latency, style control via prompts
`gemini-2.5-pro-tts`	High-quality TTS
`gemini-2.5-flash-tts`	Fast TTS
`elevenlabs/elevenlabs-tts-v2-5`	Third-party ElevenLabs

Gemini 3.1 Flash TTS Preview supports style control via natural language prompts (accents, tone, whisper, emotions), dynamic performance for poetry/newscasts/storytelling, and enhanced pace and pronunciation control.

// Synthesize and save to file
$audio = $client->audio->synthesize(
    text:        'Hello, welcome to the Agent Platform.',
    voiceConfig: ['prebuiltVoiceConfig' => ['voiceName' => 'en-US-Standard-A']],
    stylePrompt: 'Speak in a calm, friendly tone with a slight British accent.',
    outputFile:  '/tmp/speech.mp3'
);
echo $audio['savedPath'];  // /tmp/speech.mp3

// Return raw bytes (stream to browser)
$audio = $client->audio->synthesize('The quick brown fox.', 'gemini-2.5-flash-tts');
header('Content-Type: ' . $audio['mimeType']);
echo $audio['bytes'];

// ElevenLabs via Agent Platform
$audio = $client->audio->synthesize(
    text:    'Hello from ElevenLabs.',
    modelId: 'elevenlabs/elevenlabs-tts-v2-5',
    extra:   ['voice_id' => 'YOUR_VOICE_ID']
);

Anthropic Claude

Available Models

Model ID	Full Publisher Path
`anthropic/claude-sonnet-4-6`	`publishers/anthropic/models/claude-sonnet-4-6`
`anthropic/claude-opus-4-6`	`publishers/anthropic/models/claude-opus-4-6`

Requires Cloud Mode. Recommended location: us-east5.

Key differences from the direct Anthropic API:

model is not a valid body parameter — it's part of the endpoint URL.
anthropic_version is required and automatically set to vertex-2023-10-16.

$client = new Client([
    'project_id'   => 'your-gcp-project-id',
    'access_token' => 'YOUR_ACCESS_TOKEN',
    'location'     => 'us-east5',
]);

$response = $client->claude->messages(
    messages:  [['role' => 'user', 'content' => 'Give me a banana bread recipe.']],
    modelId:   'anthropic/claude-sonnet-4-6',
    maxTokens: 1024
);
echo $response['content'][0]['text'];

// Streaming
$response = $client->claude->messages(
    messages:  [['role' => 'user', 'content' => 'Write a short story.']],
    maxTokens: 1024,
    stream:    true
);

Video Generation — Veo 3.1

Veo uses a long-running operation pattern: submit a job, then poll until complete.

Available Models

Model ID	Full Publisher Path
`google/veo-3.1-generate-001`	`publishers/google/models/veo-3.1-generate-001`

$client = new Client([
    'project_id'   => 'your-gcp-project-id',
    'access_token' => 'YOUR_ACCESS_TOKEN',
    'location'     => 'us-central1',
]);

// Step 1: Submit
$operation = $client->video->generate(
    prompt:           'A timelapse of a sunflower blooming in a garden.',
    sampleCount:      1,
    outputStorageUri: 'gs://your-bucket/output/'  // optional
);

// Step 2: Poll
do {
    sleep(5);
    $status = $client->video->getOperation($operation['name']);
} while (empty($status['done']));

print_r($status['response']);

// Advanced parameters
$operation = $client->video->generate(
    prompt:           'Aerial drone shot of a mountain range at sunrise.',
    sampleCount:      2,
    outputStorageUri: 'gs://your-bucket/output/',
    additionalParams: ['generateAudio' => true, 'durationSeconds' => 8]
);

Model Reference

Model ID	Type	Resource	Notes
`gemini-3.1-flash-lite-preview`	Text	`$client->text`	Default model
`gemini-3.1-pro-preview`	Text	`$client->text`	High capability
`imagen-3.0-generate-001`	Image	`$client->images`	Highest quality
`imagen-3.0-fast-generate-001`	Image	`$client->images`	Faster, lower cost
`gemini-3.1-flash-tts-preview`	TTS	`$client->audio`	Low-latency, style control
`gemini-2.5-pro-tts`	TTS	`$client->audio`	High quality
`gemini-2.5-flash-tts`	TTS	`$client->audio`	Fast
`anthropic/claude-sonnet-4-6`	Text	`$client->claude`	Requires Cloud Mode
`anthropic/claude-opus-4-6`	Text	`$client->claude`	Requires Cloud Mode
`google/veo-3.1-generate-001`	Video	`$client->video`	Long-running operation
`elevenlabs/elevenlabs-tts-v2-5`	TTS	`$client->audio`	Third-party

About Google Agent Platform (formerly Vertex AI)

Google Agent Platform was formerly known as Vertex AI. The rebrand reflects Google's strategic shift toward agentic AI — systems that can plan, reason, and act autonomously. The underlying infrastructure and all Vertex AI API endpoints remain fully compatible. Existing code using Vertex AI endpoints will continue to work without changes.

Name		Name	Last commit message	Last commit date
Latest commit History 31 Commits
src		src
tests		tests
.gitignore		.gitignore
.phpunit.result.cache		.phpunit.result.cache
CHANGELOG.md		CHANGELOG.md
LICENSE		LICENSE
README.md		README.md
composer.json		composer.json
composer.lock		composer.lock
phpunit.xml		phpunit.xml

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Repository files navigation

Google Agent Platform PHP SDK

Installation

Quick Start

Architecture

Resource API (recommended)

Legacy flat API (fully backward-compatible)

Sending Files to Models

Strategy 1 — inlineData (local file, < ~20 MB)

Strategy 2 — File API upload (any size, reusable for 48 h)

Text Generation — Gemini

Image Generation — Imagen 3

Available Models

Text-to-Speech (TTS)

Available Models

Anthropic Claude

Available Models

Video Generation — Veo 3.1

Available Models

Model Reference

About Google Agent Platform (formerly Vertex AI)

About

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Releases 7

Contributors

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Repository files navigation

Google Agent Platform PHP SDK

Installation

Quick Start

Architecture

Resource API (recommended)

Legacy flat API (fully backward-compatible)

Sending Files to Models

Strategy 1 — inlineData (local file, < ~20 MB)

Strategy 2 — File API upload (any size, reusable for 48 h)

Text Generation — Gemini

Image Generation — Imagen 3

Available Models

Text-to-Speech (TTS)

Available Models

Anthropic Claude

Available Models

Video Generation — Veo 3.1

Available Models

Model Reference

About Google Agent Platform (formerly Vertex AI)

About

Resources

License

Uh oh!

Stars

Watchers

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Releases 7

Contributors

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