# FLUX.3 Klein API

> Téacs-go-íomhá le méideanna dúchasacha 4K, rialú roghnach leagan amach boscaí teorannaithe agus suas le 4 íomhá in aghaidh an iarratais

Gineann sé íomhánna ó `prompt` téacs mionsonraithe. Is féidir le gach taobh de `image_size` a bheith idir 256 agus 4096 picteilín, agus is féidir 1 go 4 íomhá a iarraidh in aghaidh an ghlao. Ligeann suas le 32 `bounding_boxes` duit réada ainmnithe a shuíomh in áiteanna socraithe sa fhráma. Is féidir png, jpeg nó webp a bheith san aschur, agus is féidir leathnú leide a chasadh air nó as.

- Model id: `blackforestlabs/flux-3/klein/text-to-image`
- Made by: Black Forest Labs
- Category: Text to Image
- Output: image
- Price per run: from $0.008 / run of output image (cheapest run $0.008 (8 API credits))
- Run: `POST https://api.doitong.ru/v1/run/blackforestlabs/flux-3/klein/text-to-image`
- Quote: `POST https://api.doitong.ru/v1/quote/blackforestlabs/flux-3/klein/text-to-image`
- Docs page: https://doitong.com/ga/developers/models/blackforestlabs/flux-3/klein/text-to-image

## Pricing

Price: **from $0.008 / 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.

The full example input below costs $0.009 = 9 API credits (1 run × $0.009).

Prices are the upstream price in USD, paid from the API balance in API credits (1000 API credits = 1 USD). `POST https://api.doitong.ru/v1/quote/blackforestlabs/flux-3/klein/text-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 |
|---|---|---|---|---|---|---|
| `prompt` |  | string | yes |  |  | Treoracha giniúna íomhá a chuireann síos go mion ar an ábhar, an bhfrámú, an soilsiú agus an gcúlra, ag teacht leis na fotheidil mhionsonraithe a úsáideadh chun an tsamhail a oiliúint. |
| `enable_prompt_expansion` |  | boolean | no | `true` |  | Leathnú na leide ina fotheideal mionsonraithe roimh ghiniúint, cumasaithe nuair is true an luach. Le haghaidh eagarthóireachta, bunaítear an fotheideal ar na híomhánna tagartha. |
| `seed` |  | integer \| null | no |  |  | Síol le haghaidh íomhánna in-atáirgthe: cruthaíonn leid agus síol comhionanna íomhá chomhionann nuair nach n-athraítear leagan na samhla. |
| `num_images` | `num_outputs` | integer | no | `1` | 1 – 4 | Líon na n-íomhánna a iarrtar don ghiniúint. |
| `enable_safety_checker` |  | boolean | no | `true` |  | Gníomhachtú an tseiceálaí sábháilteachta; cumasaíonn true an tseiceáil. |
| `output_format` |  | enum (string) | no | `png` | `jpeg`, `png`, `webp` | Formáid comhaid na híomhá deiridh. |
| `image_size` |  | object {width, height} \| enum (string) | no | `square_hd` | `square_hd`, `square`, `portrait_4_3`, `portrait_16_9`, `landscape_4_3`, `landscape_16_9` | Socraigh leithead agus airde an aschuir go neamhspleách laistigh de 256–4096 picteilín, le tacaíocht do ghiniúint dhúchasach 4K. |
| `bounding_boxes` |  | array of object {label, description, box} \| null | no |  | ≤ 32 items | Leagan amach roghnach i mboscaí a choinníonn gach réad a ndéantar cur síos air laistigh dá bhosca sannta; sainaithin boscaí le lipéid sa leid, m.sh. `A red fox <fox> sits under a red umbrella <umbrella>`. Léiríonn na comhordanáidí imill na mboscaí mar chodáin de thoisí na híomhá, tomhaiste ón mbunphointe uachtarach ar chlé (0, 0). |
| `bounding_boxes[].label` |  | string \| null | no |  | ≤ 64 characters | Lipéad gearr réada don bhosca, amhail `fox`; is é `obj_<n>` an réamhshocrú. Cuir `<fox>` sa leid chun a focail a cheangal leis an mbosca; cuirtear boscaí nach luaitear sa leid leis an radharc. |
| `bounding_boxes[].description` |  | string | yes |  | ≤ 500 characters | An réad atá le rindreáil sa bhosca, a chuma san áireamh. |
| `bounding_boxes[].box` |  | object {x_min, y_min, x_max, y_max} | yes |  |  | Suíomh an réada san íomhá aschuir. |
| `bounding_boxes[].box.x_min` |  | number | yes |  | 0 – 1 | An teorainn chlé i gcoibhneas le leithead na híomhá, ó 0 go 1. |
| `bounding_boxes[].box.y_min` |  | number | yes |  | 0 – 1 | An teorainn uachtarach i gcoibhneas le hairde na híomhá, ó 0 go 1. |
| `bounding_boxes[].box.x_max` |  | number | yes |  | 0 – 1 | An teorainn dheas i gcoibhneas le leithead na híomhá, ó 0 go 1. |
| `bounding_boxes[].box.y_max` |  | number | yes |  | 0 – 1 | An teorainn íochtarach i gcoibhneas le hairde na híomhá, ó 0 go 1. |

## Example input

Required parameters only:

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

A fuller example:

```json
{
  "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.ru/v1/run/blackforestlabs/flux-3/klein/text-to-image?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"
  }'

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

### JavaScript

```javascript
const API = "https://api.doitong.ru/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/blackforestlabs/flux-3/klein/text-to-image?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"
  }),
});
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.ru/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",
}

# Run the model; wait up to 20 s for the finished result in the same call
r = requests.post(API + "/run/blackforestlabs/flux-3/klein/text-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.ru/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": "blackforestlabs/flux-3/klein/text-to-image",
      "input": {
        "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": "blackforestlabs/flux-3/klein/text-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": 9,
    "usd": "0.009",
    "charged": 9,
    "refunded": 0
  },
  "input": {
    "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",
        "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.ru/v1/requests/req_8k2m4q7x1z9c3v5b6n0p2r4t",
    "cancel": "https://api.doitong.ru/v1/requests/req_8k2m4q7x1z9c3v5b6n0p2r4t/cancel"
  }
}
```

### Output fields (`output`)

| Field | Type | Description |
|---|---|---|
| `images` | array of object {url, content_type, file_name, file_size, width, height} | Íomhánna a tháirgeann an tsamhail. |
| `timings` | object | Eolas ama faoin bpróiseas giniúna. |
| `seed` | integer | Síol giniúna don chéad íomhá. |
| `has_nsfw_concepts` | array of boolean | Léiríonn sé cibé acu an bhfuil coincheapa NSFW le feiceáil sna híomhánna ginte. |
| `prompt` | string | Leid a úsáidtear le linn giniúint íomhá. |

## Related models

- [FLUX.3 Klein Image Editing](https://doitong.com/developers/models/blackforestlabs/flux-3/klein/edit-image.md) (`blackforestlabs/flux-3/klein/edit-image`): from $0.008 / run of output image
- [FLUX.1 \[dev\]](https://doitong.com/developers/models/flux/dev.md) (`flux/dev`): $0.025 / megapixel
- [FLUX.1 \[schnell\]](https://doitong.com/developers/models/flux/schnell.md) (`flux/schnell`): $0.003 / megapixel
- [FLUX.2 \[dev\]](https://doitong.com/developers/models/flux-2.md) (`flux-2`): $0.012 / megapixel
- [FLUX.2 \[pro\]](https://doitong.com/developers/models/flux-2-pro.md) (`flux-2-pro`): $0.015 / megapixel of output image
- [GPT Image 2.5 Text to Image](https://doitong.com/developers/models/openai/gpt-image-2.5/flare/text-to-image.md) (`openai/gpt-image-2.5/flare/text-to-image`): from $0.008 / image
- [Ideogram V4.5](https://doitong.com/developers/models/ideogram/v4.5.md) (`ideogram/v4.5`): from $0.03 / image
- [Nano Banana 2](https://doitong.com/developers/models/nano-banana-2.md) (`nano-banana-2`): from $0.06 / image

## Links

- HTML page: https://doitong.com/developers/models/blackforestlabs/flux-3/klein/text-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=blackforestlabs/flux-3/klein/text-to-image
- Errors: https://doitong.com/developers/docs/errors
- Model details as JSON: https://api.doitong.ru/v1/models/blackforestlabs/flux-3/klein/text-to-image