# FLUX.3 Klein API

> Maandishi hadi picha yenye saizi asilia za 4K, udhibiti wa hiari wa mpangilio kwa kisanduku cha mipaka na hadi picha 4 kwa ombi

Huzalisha picha kutoka kwa `prompt` ya maandishi yenye maelezo. Kila upande wa `image_size` unaweza kuwa kati ya pikseli 256 na 4096, na unaweza kuomba picha 1 hadi 4 kwa ombi. Hadi `bounding_boxes` 32 hukuruhusu kuweka vitu vilivyopewa majina katika nafasi maalum kwenye fremu. Tokeo linaweza kuwa png, jpeg au webp, na upanuzi wa kidokezo unaweza kuwashwa au kuzimwa.

- 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/sw/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 |  |  | Maelekezo ya uzalishaji wa picha yanayoeleza kwa kina mhusika, upangaji wa fremu, mwangaza na mandharinyuma, yakilingana na maelezo ya kina yaliyotumika kufunza modeli. |
| `enable_prompt_expansion` |  | boolean | no | `true` |  | Upanuzi wa kidokezo kuwa maelezo ya kina kabla ya uzalishaji, unaowashwa ikiwa true. Kwa uhariri, maelezo hayo hutegemea picha za marejeleo. |
| `seed` |  | integer \| null | no |  |  | Seed ya picha zinazoweza kurudiwa: kidokezo na seed zinazofanana huzalisha picha inayofanana wakati toleo la modeli halijabadilika. |
| `num_images` | `num_outputs` | integer | no | `1` | 1 – 4 | Idadi ya picha iliyoombwa kwa uzalishaji. |
| `enable_safety_checker` |  | boolean | no | `true` |  | Uanzishaji wa kikagua usalama; true huanzisha ukaguzi. |
| `output_format` |  | enum (string) | no | `png` | `jpeg`, `png`, `webp` | Muundo wa faili wa picha inayotokana. |
| `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` | Weka upana na urefu wa tokeo kwa kujitegemea ndani ya pikseli 256–4096, ukiunga mkono uzalishaji wa asili wa 4K. |
| `bounding_boxes` |  | array of object {label, description, box} \| null | no |  | ≤ 32 items | Mpangilio wa hiari wenye visanduku unaozuia kila kitu kilichoelezwa ndani ya kisanduku chake; bainisha visanduku kupitia lebo za kidokezo, kwa mfano `A red fox <fox> sits under a red umbrella <umbrella>`. Kuratibu huonyesha kingo za visanduku kama sehemu za vipimo vya picha, zikianzia kwenye (0, 0) ya kona ya juu kushoto. |
| `bounding_boxes[].label` |  | string \| null | no |  | ≤ 64 characters | Lebou fupi ya kitu kwa kisanduku, kama `fox`; chaguomsingi ni `obj_<n>`. Jumuisha `<fox>` kwenye kidokezo ili kuhusisha maneno yake na kisanduku; visanduku visivyotajwa kwenye kidokezo huongezwa kwenye tukio. |
| `bounding_boxes[].description` |  | string | yes |  | ≤ 500 characters | Kitu cha kutoa ndani ya kisanduku, pamoja na mwonekano wake. |
| `bounding_boxes[].box` |  | object {x_min, y_min, x_max, y_max} | yes |  |  | Uwekaji wa kitu ndani ya picha ya tokeo. |
| `bounding_boxes[].box.x_min` |  | number | yes |  | 0 – 1 | Mpaka wa kushoto unaoonyeshwa kulingana na upana wa picha, kutoka 0 hadi 1. |
| `bounding_boxes[].box.y_min` |  | number | yes |  | 0 – 1 | Mpaka wa juu unaoonyeshwa kulingana na urefu wa picha, kutoka 0 hadi 1. |
| `bounding_boxes[].box.x_max` |  | number | yes |  | 0 – 1 | Mpaka wa kulia unaoonyeshwa kulingana na upana wa picha, kutoka 0 hadi 1. |
| `bounding_boxes[].box.y_max` |  | number | yes |  | 0 – 1 | Mpaka wa chini unaoonyeshwa kulingana na urefu wa picha, kutoka 0 hadi 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} | Picha zilizozalishwa na modeli. |
| `timings` | object | Maelezo ya muda wa mchakato wa uzalishaji. |
| `seed` | integer | Seed ya uzalishaji kwa picha ya kwanza. |
| `has_nsfw_concepts` | array of boolean | Huonyesha ikiwa dhana za NSFW zinaonekana katika picha zilizozalishwa. |
| `prompt` | string | Kidokezo kinachotumika wakati wa uzalishaji wa picha. |

## 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