[Bug]: Exception 'TypeError' with message 'OpenAI\Exceptions\ErrorException::__construct(): Argument #1 ($contents) must be of type array, string given, called in vendor/openai-php/client/src/Transporters/HttpTransporter.php on line 133'

[vadimermolenko8787]

### Description

When calling OpenAI::models()->list(), an uncaught TypeError is thrown due to ErrorException::__construct() receiving a string instead of the expected array.

Stack trace:
#0 vendor/openai-php/client/src/Transporters/HttpTransporter.php(133): OpenAI\Exceptions\ErrorException->__construct('PostgresConnect...', 503)
#1 vendor/openai-php/client/src/Transporters/HttpTransporter.php(57): OpenAI\Transporters\HttpTransporter->throwIfJsonError(Array, '{"error":"Postg...')
#2 vendor/openai-php/client/src/Resources/Models.php(28): OpenAI\Transporters\HttpTransporter->requestObject(Object(OpenAI\ValueObjects\Transporter\Payload))
#3 backend/modules/aiAssistant/services/AiService.php(190): OpenAI\Resources\Models->list()

Cause

The throwIfJsonError() method passes the raw response body (a string) into ErrorException::__construct() expecting it to be an array. However, when the response is invalid JSON or a plain error string (e.g., "PostgresConnectionError"), this causes a fatal TypeError.

Expected behavior

The SDK should gracefully handle string error responses and normalize them into an appropriate format before passing to ErrorException.

Suggested fix

Add a type check or JSON decode fallback in HttpTransporter::throwIfJsonError() before instantiating ErrorException.

if (is_string($body)) {
$decoded = json_decode($body, true);
if (json_last_error() === JSON_ERROR_NONE && is_array($decoded)) {
$body = $decoded;
} else {
$body = ['error' => $body];
}
}

SDK Version

openai-php/client version: v^0.10.3 

PHP version: 8.3

Framework: Yii2

Additional context

Triggered during a call to OpenAI::models()->list() — most likely while OpenAI returned a non-JSON 503 error response (PostgresConnectionError).

Steps To Reproduce

Install the openai-php/client package (I was using version x.x.x, please adjust to your actual version).

Call the method OpenAI::models()->list() (or any other method that triggers an API call).

Simulate an API error response by:

Using an invalid API key,

Disabling the internet connection,

Or waiting for a temporary OpenAI outage (e.g., 503 PostgresConnectionError).

Observe that a raw TypeError is thrown instead of a handled exception.

OpenAI PHP Client Version

v0.10.3

PHP Version

8.3

Notes

No response

[iBotPeaches]

We do have a lot of existing PRs and issues about error handling. Something I'm hoping to get to spend some time on and resolve.

#326
#339
#341
#402

#553
#440
#429
#359

So I'm going to close this issue, but this is something on my mind to work on.