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FLUX.3 Klein

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Model id blackforestlabs/flux-3/klein/text-to-image
# 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"

Files like the example: $0.009 9 API credits · ≈ ₽0.97 your files are measured before the run Run it on this page

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Black Forest Labs Text to Image #image-generation#text-to-image#typography#graphic-design

Text-to-image with native 4K sizes, optional bounding-box layout control and up to 4 images per request

Made on Doitong

Public works made with FLUX.3 Klein by the Doitong community. Reuse a prompt in one click.

Public works shown: 9
Close-up portrait seorang wanita berkulit pucat berdiri setengah tubuh di dalam air berwarna lemb...

Close-up portrait seorang wanita berkulit pucat berdiri setengah tubuh di dalam air berwarna lembut kebiruan, dikelilingi bunga teratai berkelopak penuh yang bermekaran indah di permukaan air. Rambutnya pirang pucat tersanggul longgar dengan beberapa helaian tipis jatuh alami membingkai sisi...

Close-up portrait seorang wanita berkulit pucat berdiri setengah tubuh di dalam air berwarna lemb...

Close-up portrait seorang wanita berkulit pucat berdiri setengah tubuh di dalam air berwarna lembut kebiruan, dikelilingi bunga teratai berkelopak penuh yang bermekaran indah di permukaan air. Rambutnya pirang pucat tersanggul longgar dengan beberapa helaian tipis jatuh alami membingkai sisi...

Prompt Details Seorang wanita berkulit pucat berdiri setengah tubuh di dalam air berwarna lembut ...

Prompt Details Seorang wanita berkulit pucat berdiri setengah tubuh di dalam air berwarna lembut kebiruan, dikelilingi bunga teratai berkelopak penuh yang bermekaran indah di permukaan air. Rambutnya pirang pucat tersanggul longgar dengan beberapa helaian tipis jatuh alami membingkai sisi...

Seorang wanita berkulit pucat berdiri setengah tubuh di dalam air berwarna lembut kebiruan, dikel...

Seorang wanita berkulit pucat berdiri setengah tubuh di dalam air berwarna lembut kebiruan, dikelilingi bunga teratai berkelopak penuh yang bermekaran indah di permukaan air. Rambutnya pirang pucat tersanggul longgar dengan beberapa helaian tipis jatuh alami membingkai sisi wajahnya. Ia memeluk...

​"Potret sinematik ultra-realistis close-up seorang anak laki-laki kecil (balita) yang sangat men...

​"Potret sinematik ultra-realistis close-up seorang anak laki-laki kecil (balita) yang sangat menggemaskan dengan mata cokelat besar yang ekspresif, rambut hitam berantakan yang tebal, mengenakan kaus putih kerah henley. Dia berpose dengan kedua tangan terkatup di depan dada, menunjukkan senyum...

​"Potret sinematik ultra-realistis close-up seorang anak laki-laki kecil (balita) yang sangat men...

​"Potret sinematik ultra-realistis close-up seorang anak laki-laki kecil (balita) yang sangat menggemaskan dengan mata cokelat besar yang ekspresif, rambut hitam berantakan yang tebal, mengenakan kaus putih kerah henley. Dia berpose dengan kedua tangan terkatup di depan dada, menunjukkan senyum...

​"Potret sinematik ultra-realistis close-up seorang anak laki-laki kecil (balita) yang sangat men...

​"Potret sinematik ultra-realistis close-up seorang anak laki-laki kecil (balita) yang sangat menggemaskan dengan mata cokelat besar yang ekspresif, rambut hitam berantakan yang tebal, mengenakan kaus putih kerah henley. Dia berpose dengan kedua tangan terkatup di depan dada, menunjukkan senyum...

Foto sinematik hiper-realistis resolusi tinggi menampilkan seorang pria muda Indonesia dengan tub...

Foto sinematik hiper-realistis resolusi tinggi menampilkan seorang pria muda Indonesia dengan tubuh ramping dan proporsional, rambut hitam pendek agak acak, mengenakan jaket kulit hitam, celana riding fit, dan sepatu motor. Ia sedang melakukan aksi freestyle ekstrem dengan motor sport 500cc...

Build a request

Controls are generated from the model schema. The code and the price update as you change them.

•required

Image-generation instructions describing subject, framing, lighting, and background in detail, matching the detailed captions used to train the model.

image_size default square_hd

Set the output width and height independently within 256–4096 pixels, supporting native 4K generation.

num_images default 1

Image count requested for generation.

Advanced output_format · seed · enable_prompt_expansion · enable_safety_checker · bounding_boxes
output_format default png

File format for the resulting image.

Seed for reproducible images: an identical prompt and seed produce an identical image when the model version is unchanged.

Optional boxed layout that confines each described object to its assigned box; identify boxes through prompt labels, e.g. `A red fox <fox> sits under a red umbrella <umbrella>`. Coordinates express box edges as fractions of image dimensions, measured from the top-left origin (0, 0).

POST /run/blackforestlabs/flux-3/klein/text-to-image?wait=20 quote → $0.009
# 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"

Run this request

Your key stays in this browser: it is sent only to the Doitong API and saved (localStorage) only if you tick Remember. Get an API key

About FLUX.3 Klein

Generates images from a detailed text `prompt`. Each side of `image_size` can range from 256 to 4096 pixels, and you can request 1 to 4 images per call. Up to 32 `bounding_boxes` let you place named objects at set positions in the frame. Output can be png, jpeg or webp, and prompt expansion can be turned on or off.

Parameters

Send either the canonical name or the native name, not both. Canonical names

NameType DefaultAllowed Description
promptrequired
Typestring
Image-generation instructions describing subject, framing, lighting, and background in detail, matching the detailed captions used to train the model.
enable_prompt_expansionoptional
Typeboolean
Defaulttrue
Prompt expansion into a detailed caption before generation, enabled when true. For editing, the caption is grounded in the reference images.
seedoptional
Typeinteger | null
Seed for reproducible images: an identical prompt and seed produce an identical image when the model version is unchanged.
num_imagesoptional num_outputs
Typeinteger
Default1
1 – 4
Image count requested for generation.
enable_safety_checkeroptional
Typeboolean
Defaulttrue
Safety checker activation; true enables checking.
output_formatoptional
Typeenum
Defaultpng
jpegpngwebp
File format for the resulting image.
image_sizeoptional
Typeobject
Defaultsquare_hd
square_hdsquareportrait_4_3portrait_16_9landscape_4_3landscape_16_9
Set the output width and height independently within 256–4096 pixels, supporting native 4K generation.
bounding_boxesoptional
Typeobject[]
≤ 32 items
Optional boxed layout that confines each described object to its assigned box; identify boxes through prompt labels, e.g. `A red fox <fox> sits under a red umbrella <umbrella>`. Coordinates express box edges as fractions of image dimensions, measured from the top-left origin (0, 0).
bounding_boxes[].labeloptional
Typestring | null
≤ 64 characters
Brief object label for the box, such as `fox`; the default is `obj_<n>`. Include `<fox>` in the prompt to associate its words with the box; boxes not mentioned in the prompt are added to the scene.
bounding_boxes[].descriptionrequired
Typestring
≤ 500 characters
Object to render within the box, including its appearance.
bounding_boxes[].boxrequired
Typeobject
Object placement within the output image.
bounding_boxes[].box.x_minrequired
Typenumber
0 – 1
Left boundary expressed relative to image width, from 0 to 1.
bounding_boxes[].box.y_minrequired
Typenumber
0 – 1
Upper boundary expressed relative to image height, from 0 to 1.
bounding_boxes[].box.x_maxrequired
Typenumber
0 – 1
Right boundary expressed relative to image width, from 0 to 1.
bounding_boxes[].box.y_maxrequired
Typenumber
0 – 1
Lower boundary expressed relative to image height, from 0 to 1.
required Canonical name, also accepted

Output

GET /requests/req_8k2m4q7x1z9c3v5b6n0p2r4t
{
  "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"
  }
}
Your files, your choiceEvery outputs[].url is a copy on our storage: kept forever (paid per GB-month) or 7 days for free, by your account setting or ?storage=.
Same shape on every modeltype, url, content_type, width, height and duration, for images, video and audio alike. output is the model’s own result object.
Fields of output
images
array of object {url, content_type, file_name, file_size, width, height}Images produced by the model.
timings
objectTiming information for the generation process.
seed
integerGeneration seed for the first image.
has_nsfw_concepts
array of booleanIndicates whether NSFW concepts appear in the generated images.
prompt
stringPrompt used during image generation.

More models: Text to Image

For AI agents: this page as Markdown is at https://doitong.com/en-US/developers/models/blackforestlabs/flux-3/klein/text-to-image.md. All models and guides: https://doitong.com/developers/llms.txt