[Bug]: Undefined array key "output" in D:\XXX\vendor\openai-php\client\src\Responses\Responses\CreateResponse.php on line 116

[khorramnejadi]

Description

PHP Warning:  Undefined array key "output" in D:\PhpProjects\Farasat\AppReq\proj_composer\vendor\openai-php\client\src\Responses\Responses\CreateResponse.php on line 116
PHP Fatal error:  Uncaught TypeError: OpenAI\Actions\Responses\OutputObjects::parse(): Argument #1 ($outputItems) must be of type array, null given, called in D:\PhpProjects\Farasat\AppReq\proj_composer\vendor\openai-php\client\src\Responses\Responses\CreateResponse.php on line 116 and defined in D:\PhpProjects\Farasat\AppReq\proj_composer\vendor\openai-php\client\src\Actions\Responses\OutputObjects.php:45
Stack trace:
#0 D:\PhpProjects\Farasat\AppReq\proj_composer\vendor\openai-php\client\src\Responses\Responses\CreateResponse.php(116): OpenAI\Actions\Responses\OutputObjects::parse()
#1 D:\PhpProjects\Farasat\AppReq\proj_composer\vendor\openai-php\client\src\Resources\Responses.php(45): OpenAI\Responses\Responses\CreateResponse::from()
#2 D:\PhpProjects\Farasat\Server\openai_test1.php(26): OpenAI\Resources\Responses->create()
#3 {main}
  thrown in D:\PhpProjects\Farasat\AppReq\proj_composer\vendor\openai-php\client\src\Actions\Responses\OutputObjects.php on line 45

Steps To Reproduce

my sample code is:

<?php
require_once(__DIR__ .'/../xxx/vendor/autoload.php');
$apiKey = 'sk-xxxxxxxxxxxxxxxxxxxxx';

$models=['gemini-2.0-flash','gpt-3.5-turbo','google/gemini-2.0-flash-exp:free','openai/gpt-4o-mini','gpt-4o'];
foreach($models as $model){
    try{
        $client = OpenAI::client($apiKey);
        echo '<br/>'.$model.'<br/>';
        $response = $client->responses()->create([
            'model' => $model,
            'input' => 'Hello!',
        ]);

        $result = json_decode($response, true);
        
        if($response!=null){
            echo ' response is NOT null';
            $var = print_r($response, true);
            echo $var;
            $var = print_r($result, true);
            echo $var;
            // echo $result['choices'][0]['message']['content'] ?? 'Error in response';
            break;
        }
        else{
            echo ' ------ response "'.$model.'" is null';
        }
    }
    catch (Exception $e) {
        echo $e->getMessage();
    }
}
?>

OpenAI PHP Client Version

v0.18.0

PHP Version

8.5.1

Notes

No response

[iBotPeaches]

Well thats odd. output is where everything is, if Gemini Flash is making an OpenAI compatible Response API, then where is it? Could you get me a raw output sample of this from Gemini?

[ivanmestre]

@khorramnejadi AFAIK Gemini does not support the OpenAI Responses API, only the Chat Completions API. So instead of:

$client = OpenAI::client($apiKey);
$response = $client->responses()->create([
    'model' => $model,
    'input' => 'Hello!',
]);

You should do:

$client = OpenAI::client($apiKey);
$response = $client->chat()->create([
    'model' => $model,
    'messages' => [
        ['role' => 'user', 'content' => 'Hello!'],
    ],
]);

https://ai.google.dev/gemini-api/docs/openai

https://github.com/openai-php/client?tab=readme-ov-file#chat-resource

[Sh3rlck]

I am also getting a similar error using gemini-2.5-flash. Used to work fine, now on version 0.14.0 I am getting the following error:
array_map(): Argument #2 ($array) must be of type array, null given
using the following code:

$client = OpenAI::factory()
            ->withApiKey($apiKey)
            ->withBaseUri($provider->getBaseUrl())
            ->make();

try {
            $imageDataUri = 'data:image/jpeg;base64,' . $imageBase64;
            $result = $client->chat()->create([
                'model' => $model,
                'response_format' => [
                    'type' => 'json_object'
                ],
                'messages' => [
                    [
                        'role' => 'system',
                        'content' => $systemInstructions,
                    ],
                    [
                        'role' => 'user',
                        'content' => [
                            [
                                'type' => 'text',
                                'text' => $prompt,
                            ],
                            [
                                'type' => 'image_url',
                                'image_url' => [
                                    'url' => "$imageDataUri",
                                ],
                            ],
                        ],
                    ],
                ]
            ]);
}catch(){}

EDIT
After further debugging, I got the following error from the response:
code: 404
This model models/gemini-2.5-flash is no longer available to new users. Please update your code to use models/gemini-3.6-flash for the latest features and improvements. We recommend you to use the Interactions API.
status = NOT_FOUND
Which makes sense, however, I think this library should handle those errors and throw a proper error not a TypeError.