BatchesService::results() - incorrect return type causing PHP runtime error

[chedkowski-leonsoftware]

Hi, BatchesService::results() has incorrect return type causing PHP runtime error:

Anthropic\Core\Services\Beta\Messages\BatchesService::results(): Return value must be of type 
Anthropic\Beta\Messages\Batches\MessageBatchIndividualResponse, 
Generator returned in 
/home/leon/public_html/vendor/anthropic-ai/sdk/src/Core/Services/Beta/Messages/BatchesService.php(272)

Declared return type: MessageBatchIndividualResponse
Actual return type: Generator<MessageBatchIndividualResponse>

Environment:

• PHP: 8.4+
• SDK version: 0.3.0 (0.4.0 not released due to failing "Create releases / release (push)" job)
• declare(strict_types=1) enabled

Workaround

Use client->request() directly to bypass the buggy method:

public function retrieveBatchResult(AnthropicBatchId $batch_id): MessageBatchIndividualResponse
{
	$generator = $this->client->request(
		method: 'get',
		path: sprintf('/v1/messages/batches/%s/results', $batch_id->value),
		headers: [
			'Accept' => 'application/x-jsonl',
			'anthropic-beta' => 'message-batches-2024-09-24',
		],
	);

	$complete_content = implode('', iterator_to_array($generator));
	$decoded = json_decode($complete_content, true, 512, JSON_THROW_ON_ERROR);

	return Conversion::coerce(MessageBatchIndividualResponse::class, value: $decoded);
}

[chedkowski-leonsoftware]

I updated to 0.4.0 and I'm calling:

$this->client->beta->messages->batches->results(messageBatchID: $batch_id->value, params: []);

But I'm still getting this error:

Anthropic\Beta\Messages\Batches\MessageBatchIndividualResponse::__unserialize(): 
Argument #1 ($data) must be of type array, Generator given, called in
 /home/leon/public_html/vendor/anthropic-ai/sdk/src/Core/Concerns/SdkResponse.php on line 20 
in /home/leon/public_html/vendor/anthropic-ai/sdk/src/Core/Concerns/SdkModel.php(45)

I also tried:

$is_processing_ended = $batch->processing_status === ProcessingStatus::ENDED->value;
if ($is_processing_ended) {
	$results_stream = $this->client->beta->messages->batches->resultsStream(messageBatchID: $batch_id->value, params: []);
foreach ($results_stream as $response) {...}
}

But results_stream (Iterator) is empty, even though ProcessingStatus::ENDED is set.

[kristijan-koncar-gete]

I have the same issue. When we can expect update?

[clowerweb]

Root Cause Analysis

The /v1/messages/batches/{id}/results endpoint returns application/x-jsonl (multiple JSON objects, one per line). In the SDK, BatchesRawService::results() calls $this->client->request() without passing stream: JsonLStream::class, so RawResponse::parse() attempts to coerce the raw Generator into a single MessageBatchIndividualResponse model — which crashes at runtime.

The sibling resultsStream() method works correctly because it does pass stream: JsonLStream::class. The fix is to add the same parameter to results() and update return types from MessageBatchIndividualResponse to BaseStream across contracts and services (both Messages and Beta\Messages namespaces).

Upstream Note

This is a Stainless codegen template bug. The JSONL endpoint handler correctly generates the stream: parameter for the *Stream() method variant, but omits it for the non-stream results() variant. Both methods hit the same JSONL endpoint and require the stream class to parse the response correctly. This should be fixed in the codegen templates so it doesn't regress on the next generation pass.

Note that PR #13 (v0.6.0) does not fix this issue.

Fix

PR #15 addresses this by adding the missing stream: JsonLStream::class parameter and correcting return types across all 8 affected files.