# FLUX.2 [klein] 9B · Edit API

> Modificaziun d'imagens guidada dal prompt che prenda fin a 4 maletgs d'origin e returna 1 a 4 resultats modifitgads

Modifitgescha maletgs existents dad in `prompt` da text plus `image_urls`, che accepta maximalmain 4 maletgs. Sche `image_size` manca, suonda l'output la grondezza da l'imagin d'entrada. Ella parta la rangaziun da 4 a 8 `num_inference_steps`, 1 a 4 `num_images` e l'output jpeg, png u webp cun la varianta text-to-image. In `seed` po vegnir definì per modificaziuns reproduciblas.

- Model id: `flux-2/klein/9b/edit`
- Made by: Black Forest Labs
- Category: Image Editing
- Output: image
- Price per megapixel: $0.011 / megapixel (cheapest run $0.011 (11 API credits))
- Run: `POST https://api.doitong.com/v1/run/flux-2/klein/9b/edit`
- Quote: `POST https://api.doitong.com/v1/quote/flux-2/klein/9b/edit`
- Docs page: https://doitong.com/rm/developers/models/flux-2/klein/9b/edit

## Pricing

Price: **$0.011 / megapixel**. Price per megapixel: 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.

The full example input below costs $0.022 = 22 API credits (2 MP × $0.011).

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/flux-2/klein/9b/edit` 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 |
|---|---|---|---|---|---|---|
| `prompt` |  | string | yes |  |  | Prompt che descriva las modificaziuns dal maletg. |
| `seed` |  | integer \| null | no |  |  | Surpigliada dal seed da generaziun; sch'el vegn omess, tscherna la generaziun in seed casual. |
| `num_inference_steps` |  | integer | no | `4` | 4 – 8 | Dumber da pass d'inferenzia da manar a fin. |
| `image_size` |  | object {width, height} \| enum (string) \| null | no |  | `square_hd`, `square`, `portrait_4_3`, `portrait_16_9`, `landscape_4_3`, `landscape_16_9` | Dimensiuns dal maletg output; sche omess, correspundan las dimensiuns a quellas dal maletg input. |
| `num_images` | `num_outputs` | integer | no | `1` | 1 – 4 | Dumber da maletgs dumandà per la generaziun. |
| `enable_safety_checker` |  | boolean | no | `true` |  | Controlla da segirezza che restituescha maletgs nairs enstagl da maletgs marcads sco privlus. La valur true activa la controlla; false la deactivescha mo per contos autorisads, entant che dumondas senza autorisaziun vegnan controlladas tuttina. |
| `output_format` |  | enum (string) | no | `png` | `jpeg`, `png`, `webp` | Format da datoteca dal maletg final. |
| `image_urls` | `images` | array of image URL | yes |  |  | URLs dals maletgs d'editar, cun in limit da 4 maletgs. |

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

A fuller example:

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

## 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/flux-2/klein/9b/edit?wait=20" \
  -H "Authorization: Bearer $DOITONG_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field",
    "image_urls": [
      "https://content.doitong.com/images/showcase/v3/gen_fox_cartoon.jpg"
    ]
  }'

# 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/flux-2/klein/9b/edit?wait=20", {
  method: "POST",
  headers,
  body: JSON.stringify({
    "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field",
    "image_urls": [
      "https://content.doitong.com/images/showcase/v3/gen_fox_cartoon.jpg"
    ]
  }),
});
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 = {
    "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field",
    "image_urls": [
        "https://content.doitong.com/images/showcase/v3/gen_fox_cartoon.jpg",
    ],
}

# Run the model; wait up to 20 s for the finished result in the same call
r = requests.post(API + "/run/flux-2/klein/9b/edit", 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": "flux-2/klein/9b/edit",
      "input": {
        "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field",
        "image_urls": [
          "https://content.doitong.com/images/showcase/v3/gen_fox_cartoon.jpg"
        ]
      },
      "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": "flux-2/klein/9b/edit",
  "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": 22,
    "usd": "0.022",
    "charged": 22,
    "refunded": 0
  },
  "input": {
    "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field",
    "image_urls": [
      "https://content.doitong.com/images/showcase/v3/gen_fox_cartoon.jpg"
    ]
  },
  "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
      }
    ],
    "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, content_type, file_name, file_size, width, height} | Maletgs producids dal model. |
| `timings` | object |  |
| `seed` | integer | Seed da la generaziun dal maletg, inclusa la valur tschernida casualmain sche l'input n'ha betg furnì in seed; autramain repeta la valur furnida. |
| `has_nsfw_concepts` | array of boolean | Inditgescha sche concepts NSFW cumparan en ils maletgs generads. |
| `prompt` | string | Prompt utilisà durant la generaziun dal maletg. |

## Related models

- [FLUX.2 \[klein\] 4B](https://doitong.com/developers/models/flux-2/klein/4b.md) (`flux-2/klein/4b`): $0.005 / megapixel
- [FLUX.2 \[klein\] 4B Base](https://doitong.com/developers/models/flux-2/klein/4b/base.md) (`flux-2/klein/4b/base`): $0.009 / megapixel
- [FLUX.2 \[klein\] 9B](https://doitong.com/developers/models/flux-2/klein/9b.md) (`flux-2/klein/9b`): $0.006 / megapixel
- [FLUX.2 \[klein\] 9B Base](https://doitong.com/developers/models/flux-2/klein/9b/base.md) (`flux-2/klein/9b/base`): $0.011 / megapixel
- [FLUX.2 \[klein\] 4B Base · Edit](https://doitong.com/developers/models/flux-2/klein/4b/base/edit.md) (`flux-2/klein/4b/base/edit`): $0.009 / megapixel
- [FLUX.2 \[klein\] 4B · Edit](https://doitong.com/developers/models/flux-2/klein/4b/edit.md) (`flux-2/klein/4b/edit`): $0.01 / image
- [FLUX.2 \[klein\] 9B Base · Edit](https://doitong.com/developers/models/flux-2/klein/9b/base/edit.md) (`flux-2/klein/9b/base/edit`): $0.011 / megapixel
- [FLUX.1 Kontext \[pro\]](https://doitong.com/developers/models/flux-pro/kontext.md) (`flux-pro/kontext`): $0.04 / image

## Links

- HTML page: https://doitong.com/developers/models/flux-2/klein/9b/edit
- 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=flux-2/klein/9b/edit
- Errors: https://doitong.com/developers/docs/errors
- Model details as JSON: https://api.doitong.com/v1/models/flux-2/klein/9b/edit