Typings for ResponseImageGenCallPartialImageEvent missing properties (size, quality, background, output_format)

[VincentDevelopment]

Confirm this is a Node library issue and not an underlying OpenAI API issue

• This is an issue with the Node library

Describe the bug

Describe the bug
The ResponseImageGenCallPartialImageEvent interface is missing several fields that the API actually returns.
They are present in the image generation API though.

Current types (from 5.12.2):

export interface ResponseImageGenCallPartialImageEvent {
  item_id: string;
  output_index: number;
  partial_image_b64: string;
  partial_image_index: number;
  sequence_number: number;
  type: 'response.image_generation_call.partial_image';
}

**Actual payload observed from streaming:**

```json
{
  "type": "response.image_generation_call.partial_image",
  "sequence_number": 7,
  "output_index": 0,
  "item_id": "ig_...",
  "partial_image_index": 2,
  "partial_image_b64": "...",
  "size": "1024x1536",
  "quality": "high",
  "background": "opaque",
  "output_format": "png"
}

Expected behavior:
The type definition should include size, quality, background, and output_format (and any other fields consistently emitted).

Version:
5.12.2

To Reproduce

1. Install the latest openai npm package and set your OPENAI_API_KEY.
2. Create a script that uses the Responses API with the image_generation tool.
3. Run the script and log all response.image_generation_call.* events.
4. Observe that the response.image_generation_call.partial_image event includes extra fields (size, quality, background, output_format) that are missing from the SDK type definitions.

Code snippets

const stream = await client.responses.stream({
  model: "gpt-4o",
  input: prompt,
  tools: [{ type: "image_generation", model: "gpt-image-1", partial_images: 2 }],
  tool_choice: { type: "image_generation" as const },
  stream: true,
});

for await (const e of stream) {
  if (e.type.startsWith("response.image_generation_call")) {
    console.log("EVENT TYPE:", e.type);
    console.dir(e, { depth: null });
  }
}

OS

macOS

Node version

Node.js v23.7.0

Library version

v5.12.2

[shreyanshxyz]

No resolution yet ? +1