# Smart Resize API

> Recomposes an image to up to 10 target dimensions, useful for ad and crop variants

Resizes a source image to arbitrary sizes by regenerating the composition rather than simply cropping. Give `target_sizes` as 1 to 10 strings like "1920x1080", with 1 to 4 variants each via `num_images_per_size`. An optional `prompt` of up to 5000 characters adds instructions. `resolution` is 1K, 2K or 4K, and output is png, jpeg or webp.

- Model id: `smart-resize`
- Made by: Utility
- Category: Image Editing
- Output: image
- Price per run: from $0.15 / run of output image (cheapest run $0.15 (150 API credits))
- Run: `POST https://api.doitong.com/v1/run/smart-resize`
- Quote: `POST https://api.doitong.com/v1/quote/smart-resize`
- Docs page: https://doitong.com/developers/models/smart-resize

## Pricing

Price: **from $0.15 / run of output image** (the lowest tier; the quote prices your exact input). Price per run: the input files are measured before the run (length, resolution, frame rate). The quote measures the same files and is exactly what the run charges.

Price by tier:

- 1K: $0.15 / run of output image
- 2K: $0.15 / run of output image
- 4K: $0.30 / run of output image

The full example input below costs $0.50 = 500 API credits (3 runs × $0.15 (1K) + $0.05).

Prices are the upstream price in USD, paid from the API balance in API credits (1000 API credits = 1 USD). `POST https://api.doitong.com/v1/quote/smart-resize` with the same JSON body returns the exact price for that input; the quote is exactly what a run charges. Invalid input is never charged and failed or canceled requests are refunded automatically.

## Input parameters

Send either the canonical name or the native field name (not both). Canonical names are the same across models.

| Parameter | Canonical name | Type | Required | Default | Allowed values / range | Description |
|---|---|---|---|---|---|---|
| `image_url` | `image` | string (image URL) | yes |  |  | Source image URL for resizing. |
| `target_sizes` |  | array of string | yes |  | 1 – 10 items | Requested output dimensions as a list of `<width>x<height>` strings, for example `"1920x1080"`. Each target is covered by a nano-banana-pro preset chosen to be as small as possible while still covering the requested dimensions, giving an exact pixel match without upscaling. The image count for each size is one multiplied by `num_images_per_size`. |
| `prompt` |  | string | no | `` | ≤ 5000 characters | Additional guidance for resizing: an empty value asks the model to keep the source content as faithful as possible. Any supplied instruction accompanies the automatically generated resizing prompt sent to nano-banana-pro. |
| `num_images_per_size` |  | integer | no | `1` | 1 – 4 | Per-size variant count for nano-banana-pro, determining the total returned image count as `len(target_sizes) * num_images_per_size`. |
| `resolution` |  | enum (string) | no | `1K` | `1K`, `2K`, `4K` | Internal resolution-tier hint establishing a minimum, not the final dimensions specified by `target_sizes`. If that tier cannot accommodate a requested size, smart resizing may automatically choose a higher one. |
| `output_format` |  | enum (string) | no | `png` | `jpeg`, `png`, `webp` | Format for generated images. |
| `safety_tolerance` |  | enum (string) | no | `4` | `1`, `2`, `3`, `4`, `5`, `6` | Safety tolerance: increasing this number makes filtering less strict for the internal nano-banana-pro /edit calls. |
| `seed` |  | integer \| null | no |  |  | Optional reproducibility seed shared across all target sizes. When supplied, it is passed through to the internal nano-banana-pro /edit calls. |

File parameters (`image`) take a public `https://` URL, a `data:` URI up to 10 MB, or the `file_url` of an upload from `POST /files`.

## Example input

Required parameters only:

```json
{
  "image": "https://content.doitong.com/images/showcase/v3/gen_fox_cartoon.jpg",
  "target_sizes": [
    "1024x1024",
    "1920x1080",
    "768x1344"
  ]
}
```

A fuller example:

```json
{
  "image_url": "https://content.doitong.com/images/showcase/v3/gen_fox_cartoon.jpg",
  "target_sizes": [
    "1024x1024",
    "1920x1080",
    "768x1344"
  ]
}
```

## Run it

Set `DOITONG_API_KEY` to a key from https://doitong.com/developers/dashboard#keys. `?wait=20` returns the finished request in the same call when it is ready within 20 seconds; otherwise poll `GET /requests/{id}` (it also accepts `?wait=`), or pass `webhook_url`.

### curl

```bash
# Run the model; wait up to 20 s for the finished result in the same call
curl -X POST "https://api.doitong.com/v1/run/smart-resize?wait=20" \
  -H "Authorization: Bearer $DOITONG_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "image_url": "https://content.doitong.com/images/showcase/v3/gen_fox_cartoon.jpg",
    "target_sizes": [
      "1024x1024",
      "1920x1080",
      "768x1344"
    ]
  }'

# Still "queued" or "running"? Poll with the id from the response:
curl "https://api.doitong.com/v1/requests/REQUEST_ID?wait=20" \
  -H "Authorization: Bearer $DOITONG_API_KEY"
```

### JavaScript

```javascript
const API = "https://api.doitong.com/v1";
const headers = {
  "Authorization": "Bearer " + process.env.DOITONG_API_KEY,
  "Content-Type": "application/json",
};

// Run the model; wait up to 20 s for the finished result in the same call
let res = await fetch(API + "/run/smart-resize?wait=20", {
  method: "POST",
  headers,
  body: JSON.stringify({
    "image_url": "https://content.doitong.com/images/showcase/v3/gen_fox_cartoon.jpg",
    "target_sizes": [
      "1024x1024",
      "1920x1080",
      "768x1344"
    ]
  }),
});
let request = await res.json();
if (!res.ok) throw new Error(request.error.code + ": " + request.error.message);

// Not finished yet: long-poll until it is
while (request.status === "queued" || request.status === "running") {
  res = await fetch(API + "/requests/" + request.id + "?wait=20", { headers });
  request = await res.json();
}
if (request.status !== "succeeded") throw new Error(JSON.stringify(request.error));
console.log(request.outputs.map((o) => o.url), request.cost.credits + " API credits ($" + request.cost.usd + ")");
```

### Python

```python
import os
import requests

API = "https://api.doitong.com/v1"
headers = {"Authorization": "Bearer " + os.environ["DOITONG_API_KEY"]}

payload = {
    "image_url": "https://content.doitong.com/images/showcase/v3/gen_fox_cartoon.jpg",
    "target_sizes": [
        "1024x1024",
        "1920x1080",
        "768x1344",
    ],
}

# Run the model; wait up to 20 s for the finished result in the same call
r = requests.post(API + "/run/smart-resize", params={"wait": 20}, json=payload, headers=headers)
request = r.json()
if not r.ok:
    raise RuntimeError(request["error"]["code"] + ": " + request["error"]["message"])

# Not finished yet: long-poll until it is
while request["status"] in ("queued", "running"):
    request = requests.get(API + "/requests/" + request["id"], params={"wait": 20}, headers=headers).json()
if request["status"] != "succeeded":
    raise RuntimeError(request["error"])
print([o["url"] for o in request["outputs"]], request["cost"]["credits"], "API credits", "$" + request["cost"]["usd"])
```

### MCP

The MCP server at `https://api.doitong.com/v1/mcp` exposes the tools `search_models`, `get_model`, `quote`, `run`, `get_request`, `cancel_request`, `list_requests`, `create_upload` and `get_account`. A `run` call for this model:

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "run",
    "arguments": {
      "model_id": "smart-resize",
      "input": {
        "image_url": "https://content.doitong.com/images/showcase/v3/gen_fox_cartoon.jpg",
        "target_sizes": [
          "1024x1024",
          "1920x1080",
          "768x1344"
        ]
      },
      "wait_seconds": 20
    }
  }
}
```

## Response

Every call returns a request object. `status` is one of `queued`, `running`, `succeeded`, `failed`, `canceled`. `outputs` lists the generated files with URLs on our storage (kept forever, or 7 days with `?storage=temporary`; `storage` says which); `output` is the model's own result object with the same URLs.

```json
{
  "id": "req_8k2m4q7x1z9c3v5b6n0p2r4t",
  "object": "request",
  "model": "smart-resize",
  "status": "succeeded",
  "created_at": "2026-10-20T12:00:00Z",
  "started_at": "2026-10-20T12:00:02Z",
  "completed_at": "2026-10-20T12:00:09Z",
  "queue_position": null,
  "cost": {
    "credits": 500,
    "usd": "0.50",
    "charged": 500,
    "refunded": 0
  },
  "input": {
    "image_url": "https://content.doitong.com/images/showcase/v3/gen_fox_cartoon.jpg",
    "target_sizes": [
      "1024x1024",
      "1920x1080",
      "768x1344"
    ]
  },
  "output": {
    "images": [
      {
        "url": "https://content.doitong.com/dev-api/2026/10/20/req_8k2m4q7x1z9c3v5b6n0p2r4t/0-output.jpeg",
        "content_type": "image/jpeg",
        "file_name": "0-output.jpeg",
        "file_size": 1843200,
        "width": 1024,
        "height": 768
      }
    ],
    "description": "string",
    "results": [
      {
        "images": [
          {}
        ],
        "description": "string",
        "width": 1024,
        "height": 768,
        "aspect_ratio": "string",
        "resolution": "string"
      }
    ]
  },
  "outputs": [
    {
      "type": "image",
      "url": "https://content.doitong.com/dev-api/2026/10/20/req_8k2m4q7x1z9c3v5b6n0p2r4t/0-output.jpeg",
      "content_type": "image/jpeg",
      "file_size": 1843200,
      "width": 1024,
      "height": 768,
      "stored": true
    }
  ],
  "error": null,
  "metrics": {
    "inference_seconds": 6.8
  },
  "urls": {
    "self": "https://api.doitong.com/v1/requests/req_8k2m4q7x1z9c3v5b6n0p2r4t",
    "cancel": "https://api.doitong.com/v1/requests/req_8k2m4q7x1z9c3v5b6n0p2r4t/cancel"
  }
}
```

### Output fields (`output`)

| Field | Type | Description |
|---|---|---|
| `images` | array of object {url, content_type, file_name, file_size, width, height} | Combined image list with `num_images_per_size` entries for `target_sizes[0]` first, then equivalent groups for subsequent `target_sizes`. It includes every generated image in the same sequence as `results`. |
| `description` | string | Description accompanying the generated images. |
| `results` | array of object {images, description, width, height, aspect_ratio, resolution} | Requested width and height for each target, paired with the nano-banana-pro preset used during processing, identified by its aspect_ratio and resolution. |

## Related models

- [FLUX.1 Kontext \[pro\]](https://doitong.com/developers/models/flux-pro/kontext.md) (`flux-pro/kontext`): $0.04 / image
- [GPT Image 2.5 Edit](https://doitong.com/developers/models/openai/gpt-image-2.5/flare/edit.md) (`openai/gpt-image-2.5/flare/edit`): from $0.12 / image
- [Nano Banana 2 Edit](https://doitong.com/developers/models/nano-banana-2/edit.md) (`nano-banana-2/edit`): from $0.06 / image
- [Nano Banana Pro Edit](https://doitong.com/developers/models/nano-banana-pro/edit.md) (`nano-banana-pro/edit`): from $0.15 / image
- [Qwen Image 3 Edit](https://doitong.com/developers/models/alibaba/qwen-image-3/edit.md) (`alibaba/qwen-image-3/edit`): from $0.04 / image
- [Seedream 5.0 Pro Edit](https://doitong.com/developers/models/bytedance/seedream/v5/pro/edit.md) (`bytedance/seedream/v5/pro/edit`): from $0.0675 / run of output image
- [Age Modify](https://doitong.com/developers/models/image-apps-v2/age-modify.md) (`image-apps-v2/age-modify`): $0.04 / image
- [Cartoonify](https://doitong.com/developers/models/cartoonify.md) (`cartoonify`): $0.10 / image

## Links

- HTML page: https://doitong.com/developers/models/smart-resize
- All models and guides for AI agents: https://doitong.com/developers/llms.txt
- OpenAPI 3.1 with this model's typed request body: https://doitong.com/developers/openapi.json?model=smart-resize
- Errors: https://doitong.com/developers/docs/errors
- Model details as JSON: https://api.doitong.com/v1/models/smart-resize