# Latent Consistency Models (v1.5/XL) · Image to Image API

> Génération latente cohérente image-image restylisant une image source avec un contrôle de force

Part de `image_url` et d’un `prompt`, avec `strength` de 0.05 à 1 (0.95 par défaut) indiquant l’écart du résultat par rapport à la source. Fonctionne en peu d’étapes (6 par défaut), renvoie jusqu’à 8 images et propose les options `preserve_aspect_ratio` et `crop_output`.

- Model id: `fast-lcm-diffusion/image-to-image`
- Made by: Open model
- Category: Image Editing
- Output: image
- Estimated price per run: $0.019 / image (cheapest run $0.019 (19 API credits))
- Run: `POST https://api.doitong.com/v1/run/fast-lcm-diffusion/image-to-image`
- Quote: `POST https://api.doitong.com/v1/quote/fast-lcm-diffusion/image-to-image`
- Docs page: https://doitong.com/fr/developers/models/fast-lcm-diffusion/image-to-image

## Pricing

Price: **$0.019 / image**. Estimated from the typical cost of one run, per output (`num_images`). The quote is exactly what the run charges.

The full example input below costs $0.019 = 19 API credits (1 image × 19 API credits).

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/fast-lcm-diffusion/image-to-image` 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 |  |  | Image de départ pour la génération, fournie par URL. |
| `prompt` |  | string | yes |  |  | Décrivez l’image que vous souhaitez générer avec le plus de détails possible pour obtenir les meilleurs résultats. |
| `negative_prompt` |  | string | no | `` |  | Prompt négatif indiquant les détails d’image indésirables. Il peut exclure les couleurs, les objets, le décor ou des caractéristiques et qualités plus fines, comme une moustache, du flou ou une faible résolution. |
| `image_size` |  | object {height, width} \| enum (string) | no | `square_hd` | `square_hd`, `square`, `portrait_4_3`, `portrait_16_9`, `landscape_4_3`, `landscape_16_9` | Dimensions de l’image générée. |
| `num_inference_steps` |  | integer | no | `6` | 1 – 32 | Nombre d’étapes d’inférence à exécuter. |
| `guidance_scale` |  | number | no | `1.5` | 0 – 20 | Force d'adhérence au prompt pour la sélection d'image, exprimée comme CFG (Classifier Free Guidance). |
| `strength` |  | number | no | `0.95` | 0.05 – 1 | Degré de ressemblance entre l'image générée et l'image initiale. |
| `seed` |  | integer \| null | no |  |  | Graine permettant de reproduire des images dans Stable Diffusion. Une image peut être reproduite exactement à chaque exécution en conservant la version du modèle, le prompt et la graine inchangés. |
| `num_images` | `num_outputs` | integer | no | `1` | 1 – 8 | Nombre d'images demandé pour la génération. |
| `enable_safety_checker` |  | boolean | no | `true` |  | Activation du vérificateur de sécurité ; true active la vérification. |
| `safety_checker_version` |  | enum (string) | no | `v1` | `v1`, `v2` | Choisissez entre le vérificateur de sécurité ViT personnalisé (`v2`) et le vérificateur CompVis (`v1`, par défaut). |
| `expand_prompt` |  | boolean | no | `false` |  | Expansion du prompt avec des prompts supplémentaires, activée lorsque la valeur est true. |
| `format` |  | enum (string) | no | `jpeg` | `jpeg`, `png` | Format de fichier de l'image obtenue. |
| `request_id` |  | string | no | `` |  | Identifiant de requête permettant d'associer une réponse à la requête qui l'a produite. |
| `preserve_aspect_ratio` |  | boolean | no | `false` |  | Définissez true pour conserver le format d'image généré même lorsque sa taille dépasse la limite. Pour obtenir les proportions correctes par recadrage après la génération, définissez crop_output sur True. Les valeurs de largeur ou de hauteur non divisibles par 32 sont tout de même arrondies au multiple de 32 le plus proche, et ce redimensionnement ne conserve pas le format d'image par défaut. |
| `crop_output` |  | boolean | no | `false` |  | Recadre la sortie générée au format d'image correct lorsque la valeur est true. |

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",
  "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field"
}
```

A fuller example:

```json
{
  "image_url": "https://content.doitong.com/images/showcase/v3/gen_fox_cartoon.jpg",
  "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field"
}
```

## 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/fast-lcm-diffusion/image-to-image?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",
    "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field"
  }'

# 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/fast-lcm-diffusion/image-to-image?wait=20", {
  method: "POST",
  headers,
  body: JSON.stringify({
    "image_url": "https://content.doitong.com/images/showcase/v3/gen_fox_cartoon.jpg",
    "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field"
  }),
});
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",
    "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field",
}

# Run the model; wait up to 20 s for the finished result in the same call
r = requests.post(API + "/run/fast-lcm-diffusion/image-to-image", 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": "fast-lcm-diffusion/image-to-image",
      "input": {
        "image_url": "https://content.doitong.com/images/showcase/v3/gen_fox_cartoon.jpg",
        "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field"
      },
      "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": "fast-lcm-diffusion/image-to-image",
  "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": 19,
    "usd": "0.019",
    "charged": 19,
    "refunded": 0
  },
  "input": {
    "image_url": "https://content.doitong.com/images/showcase/v3/gen_fox_cartoon.jpg",
    "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field"
  },
  "output": {
    "images": [
      {
        "url": "https://content.doitong.com/dev-api/2026/10/20/req_8k2m4q7x1z9c3v5b6n0p2r4t/0-output.jpeg",
        "width": 1024,
        "height": 768,
        "content_type": "image/jpeg"
      }
    ],
    "timings": {},
    "seed": 42,
    "has_nsfw_concepts": [
      false
    ],
    "prompt": "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, width, height, content_type} | Informations de fichier pour les images générées. |
| `timings` | object |  |
| `seed` | integer | Seed de génération d'images, y compris la valeur choisie aléatoirement si l'entrée n'en fournissait pas ; sinon, il reprend la valeur fournie. |
| `has_nsfw_concepts` | array of boolean | Indique si des concepts NSFW apparaissent dans les images générées. |
| `prompt` | string | Prompt utilisé pendant la génération d'images. |

## Related models

- [Latent Consistency Models (v1.5/XL)](https://doitong.com/developers/models/fast-lcm-diffusion.md) (`fast-lcm-diffusion`): $0.005 / image
- [Latent Consistency Models (v1.5/XL) · Inpainting](https://doitong.com/developers/models/fast-lcm-diffusion/inpainting.md) (`fast-lcm-diffusion/inpainting`): $0.014 / image
- [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

## Links

- HTML page: https://doitong.com/developers/models/fast-lcm-diffusion/image-to-image
- 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=fast-lcm-diffusion/image-to-image
- Errors: https://doitong.com/developers/docs/errors
- Model details as JSON: https://api.doitong.com/v1/models/fast-lcm-diffusion/image-to-image