> ## Documentation Index
> Fetch the complete documentation index at: https://openrouter.ai/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Markup

A transparent PNG overlay (arrows, circles, annotations) with the same dimensions as the first reference image, as a base64 data URL or HTTP(S) URL, guiding where an edit applies. Image-to-image requests only; honored by models with markup-guided editing (OpenAI gpt-image-2.6) and ignored otherwise.

## Example Usage

```typescript theme={null}
import { Markup } from "@openrouter/sdk/models";

let value: Markup = {
  imageUrl: {
    url: "https://example.com/image.png",
  },
  type: "image_url",
};
```

## Fields

| Field | Type | Required | Description |
| - | - | - | - |
| `imageUrl` | [models.ImageGenerationRequestImageUrl](../models/imagegenerationrequestimageurl.mdx) | ✔️ | N/A |
| `type` | [models.ImageGenerationRequestType](../models/imagegenerationrequesttype.mdx) | ✔️ | N/A |