# FLUX.1 [dev] API

> דער אָפֿן־וואָג FLUX־אַרבעטספֿערד, שאַרפער און געטרײַערער צו לאַנגע פּראָמפּטן ווי schnell.

דער גיידאַנס־דיסטילירטער FLUX מאָדעל מיט 12 ביליאָן פּאַראַמעטערן און אַ פולן סאַמפּלינג־פּלאַן (סטאַנדאַרט 28 שריט, אַדזשאַסטירבאַר פֿון 1 ביז 50) און אַ פֿײַנשטעלבאַרער גיידאַנס־סקאַלע. ער פֿאָלגט דעטאַלירטע פּראָמפּטן און רענדערט הענט, פּנימער און קורצן טעקסט באַמערקבאַר בעסער ווי דער schnell וואַריאַנט, בײַ אַ העכערער פּרײַז. פּריסעט־ אָדער אייגענע גרייסן, ביז פֿיר בילדער פּער בקשה, JPEG אָדער PNG רעזולטאַט.

- Model id: `flux/dev`
- Made by: Black Forest Labs
- Category: Text to Image
- Output: image
- Price: $0.025 / megapixel (cheapest run $0.025 (25 API credits))
- Run: `POST https://api.doitong.com/v1/run/flux/dev`
- Quote: `POST https://api.doitong.com/v1/quote/flux/dev`
- Docs page: https://doitong.com/yi/developers/models/flux/dev

## Pricing

Price: **$0.025 / megapixel**. Billed per megapixel of output (width × height of every image). Each image is rounded up to a whole megapixel.

The full example input below costs $0.025 = 25 API credits (1 MP × 25 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/flux/dev` 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 |  |  | פּראָמפּט וואָס פירט בילד־גענערירונג. |
| `image_size` |  | object {width, height} \| enum (string) | no | `landscape_4_3` | `square_hd`, `square`, `portrait_4_3`, `portrait_16_9`, `landscape_4_3`, `landscape_16_9` | דימענסיעס פֿונעם גענערירטן בילד. |
| `num_inference_steps` |  | integer | no | `28` | 1 – 50 | צאָל אינפֿערענץ־סטעפּס צו לויפֿן. |
| `seed` |  | integer \| null | no |  |  | סיד פֿאַר רעפּראָדוצירבאַרע בילדער: אַן אידענטישער פּראָמפּט און סיד שאַפֿן אַן אידענטיש בילד ווען די מאָדעל־ווערסיע איז אומגעענדערט. |
| `guidance_scale` |  | number | no | `3.5` | 1 – 20 | שטאַרקייט פֿון פּראָמפּט־אנהאַלטונג פֿאַר בילד־אויסקלײַב, אויסגעדריקט ווי CFG (Classifier Free Guidance). |
| `num_images` | `num_outputs` | integer | no | `1` | 1 – 4 | געבעטן צאָל בילדער פֿאַר גענערירונג. |
| `output_format` |  | enum (string) | no | `jpeg` | `jpeg`, `png` | פֿײַל־פֿאָרמאַט פון דעם רעזולטירנדיקן בילד. |
| `acceleration` |  | enum (string) | no | `none` | `none`, `regular`, `high` | גענערירונג־אַקסעלעראַציע; העכערע באַשטעטיקונגען פֿאַרקלענערן די צײַט נייטיק צו גענערירן רעזולטאַטן. |

## Example input

Required parameters only:

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

A fuller example:

```json
{
  "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field, telephoto lens",
  "image_size": "landscape_4_3",
  "num_outputs": 1
}
```

## 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/dev?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, telephoto lens",
    "image_size": "landscape_4_3",
    "num_outputs": 1
  }'

# 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/dev?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, telephoto lens",
    "image_size": "landscape_4_3",
    "num_outputs": 1
  }),
});
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, telephoto lens",
    "image_size": "landscape_4_3",
    "num_outputs": 1,
}

# Run the model; wait up to 20 s for the finished result in the same call
r = requests.post(API + "/run/flux/dev", 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/dev",
      "input": {
        "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field, telephoto lens",
        "image_size": "landscape_4_3",
        "num_outputs": 1
      },
      "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/dev",
  "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": 25,
    "usd": "0.025",
    "charged": 25,
    "refunded": 0
  },
  "input": {
    "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field, telephoto lens",
    "image_size": "landscape_4_3",
    "num_outputs": 1
  },
  "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} | פֿײַל־אינפֿאָרמאַציע פֿאַר די גענערירטע בילדער. |
| `timings` | object |  |
| `seed` | integer | בילד־גענערירונג־סיד, אַרײַנגערעכנט דעם ראַנדאָם אויסגעקליבענעם ווערט אויב די אַרײַנגעבונג האט נישט אַרײַנגעגעבן קיין סיד; אַנדערש איבערחזרט עס דעם צוגעשטעלטן ווערט. |
| `has_nsfw_concepts` | array of boolean | ווײַזט צי NSFW־קאָנסעפּטן דערשײַנען אין די גענערירטע בילדער. |
| `prompt` | string | פּראָמפּט וואָס ווערט גענוצט בעת בילד־גענערירונג. |

## Related models

- [FLUX.1 \[schnell\]](https://doitong.com/developers/models/flux/schnell.md) (`flux/schnell`): $0.003 / megapixel
- [FLUX.1 \[dev\] Redux](https://doitong.com/developers/models/flux/dev/redux.md) (`flux/dev/redux`): $0.025 / megapixel
- [FLUX.1 \[schnell\] Redux](https://doitong.com/developers/models/flux/schnell/redux.md) (`flux/schnell/redux`): $0.025 / megapixel
- [FLUX.1 · Dev · Image to Image](https://doitong.com/developers/models/flux/dev/image-to-image.md) (`flux/dev/image-to-image`): $0.09 / image
- [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

## Links

- HTML page: https://doitong.com/developers/models/flux/dev
- 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/dev
- Errors: https://doitong.com/developers/docs/errors
- Model details as JSON: https://api.doitong.com/v1/models/flux/dev