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XAIImageModel lives in the AiSdk\XAI\Models namespace and is the concrete image model implementation for xAI’s Grok image generation API. It extends BaseModel and implements ImageModelInterface, using the shared aisdk/openai-compatible helpers — ImageRequestBuilder constructs the outgoing payload and ImageResponseParser decodes the response. Because xAI’s image endpoint uses an aspect_ratio field rather than a pixel size string, the model is pre-configured with xAI-specific builder options that suppress the size and seed parameters automatically.

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Namespace

use AiSdk\XAI\Models\XAIImageModel;
XAIImageModel is typically obtained via XAI::image() rather than constructed directly. See the XAI facade reference for setup instructions.

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Constructor

public function __construct(
    private readonly string $modelId,
    private readonly XAIOptions $options,
    private readonly ?ModelRegistry $registry = null,
)
ParameterTypeDescription
$modelIdstringThe image model identifier, e.g. 'grok-imagine-image-quality'.
$optionsXAIOptionsProvider configuration: base URL, API key, and SDK HTTP dependencies.
$registryModelRegistry|nullOptional runtime registry for custom capability overrides. Defaults to null.

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Methods

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provider(): string

Returns the provider name used throughout the SDK for namespacing metadata and capability lookups. 
$model->provider(); // 'xai'

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modelId(): string

Returns the model identifier that was supplied at construction time. 
$model->modelId(); // e.g. 'grok-imagine-image-quality'

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capabilities(): array<int, Capability>

Returns the full list of Capability enum cases supported by this model. The method resolves the list in priority order:
  1. Model registry — if a ModelRegistry was injected and contains an entry for this (provider, modelId) pair, that definition’s capability list is used.
  2. Catalog — otherwise the bundled resources/models.json catalog is consulted.
$capabilities = XAI::image('grok-imagine-image-quality')->capabilities();
// [Capability::ImageGeneration, Capability::TextInput, Capability::ImageInput]
The grok-imagine-image-quality catalog entry declares three capabilities: ImageGeneration, TextInput, and ImageInput.

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capability(Capability $capability): CapabilitySupport

Resolves the support status for a single capability, walking the following chain until a definitive answer is found:
  1. Configured overrides — capability flags set on the XAIOptions instance.
  2. Model registry — result from the injected ModelRegistry, if present.
  3. Catalog — bundled resources/models.json.
use AiSdk\Capability;

$support = XAI::image('grok-imagine-image-quality')->capability(Capability::ImageGeneration);
$support->isSupported(); // true

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generate(ImageRequest $request): ImageResponse

Sends an image generation request and returns a fully-resolved ImageResponse. Internally:
  • Serialises the request with ImageRequestBuilder::build() using the following xAI-specific options:
    OptionValueEffect
    aspectRatioParameter'aspect_ratio'Sends aspect ratio as aspect_ratio in the request body.
    inferSizeFromAspectRatiofalseDisables automatic size inference from aspect ratio.
    sizeParameternullThe size field is never included in the request.
    seedParameternullThe seed field is never included in the request.
  • POSTs to {baseUrl}/images/generations via the SDK HTTP runner.
  • Deserialises the JSON response with ImageResponseParser::parse(). 
$result = Generate::image()
    ->model(XAI::image('grok-imagine-image-quality'))
    ->prompt('A futuristic skyline')
    ->count(2)
    ->aspectRatio('16:9')
    ->run();

echo $result->output->base64;
$result->output->save('/tmp/image.png');
You can also pass xAI-specific raw fields (such as resolution) via providerOptions(): 
$result = Generate::image()
    ->model(XAI::image('grok-imagine-image-quality'))
    ->prompt('A futuristic skyline')
    ->aspectRatio('16:9')
    ->providerOptions('xai', ['raw' => ['resolution' => '2k']])
    ->run();
ParameterTypeDescription
$requestImageRequestThe portable image model request object.
Returns ImageResponse — contains output (with base64 and a save() helper), usage, and providerMetadata.

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Endpoint

POST {baseUrl}/images/generations
Default base URL: https://api.x.ai/v1
Full default endpoint: https://api.x.ai/v1/images/generations The base URL can be overridden by passing a custom baseUrl in XAI::create() options.

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Response format

All image responses are returned as b64_json — the response body carries base-encoded image data, accessible via $result->output->base64. The size parameter is never sent to the xAI API; use ->aspectRatio() on the Generate::image() builder to control image dimensions instead.

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