response API added

[rafasashi]

I have added support for the v1/response API

• background => true enables background/asynchronous processing.
• GET /responses/{id} checks the status.
• POST /responses/{id}/cancel cancels it.
• stream => true streams output immediately and is not background processing.

$payload = [
    'model' => 'gpt-4.1-mini',
    'input' => 'Process this task in the background.',
    'background' => true,
];

$response = $this->post(
    Url::responsesUrl(),
    $payload
);

The API will return a response ID. You can poll it using:

$responseId = $response['id'];

$status = $this->get(
    Url::responseUrl($responseId)
);

Example polling loop:

do {
    sleep(2);

    $response = $this->get(
        Url::responseUrl($responseId)
    );

    $status = $response['status'];
} while (in_array($status, ['queued', 'in_progress'], true));

if ($status === 'completed') {
    // Process the completed response.
} else {
    // Handle failed or cancelled response.
}

To cancel a background response:

$this->post(
    Url::cancelResponseUrl($responseId),
    []
);

Streaming usage:

$payload = [
    'model' => 'gpt-4.1-mini',
    'input' => 'Stream this response.',
    'stream' => true,
];