# FLUX 3 API

> FLUX 3 video with sound up to 20 seconds: from a description, from frames or continuing an existing clip. A draft costs about a third of a full video.

Developer: Black Forest Labs
Model key in the API: `flux3`

## Connect in three steps

1. [Get a key](https://api.cyhub.ai/docs/connection.md?lang=en): Create a key in the dashboard after you confirm your email. One key opens every model.
2. [Check the price](https://api.cyhub.ai/docs/generations.md?lang=en): POST /v1/price shows the cost of a run in advance, without charging you.
3. [Run a task and collect the result](https://api.cyhub.ai/docs/tasks.md?lang=en): POST /v1/tasks starts a task, GET /v1/tasks/{id} shows its status and files.

## Ready-to-use code

Replace YOUR_API_KEY with your key. The code starts a task and waits for the result. In cURL, repeat the second request with the id from the first response instead of TASK_ID until status becomes succeeded.

```bash
curl -X POST "https://api.cyhub.ai/v1/tasks" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  --data '{
  "model": "flux3",
  "settings": {
    "mode": "t2v",
    "prompt": "Лиса бежит сквозь утренний туман, под лапами хрустят ветки",
    "aspect_ratio": "16:9",
    "duration": 8
  }
}'

curl "https://api.cyhub.ai/v1/tasks/TASK_ID" \
  -H "Authorization: Bearer YOUR_API_KEY"
```

```python
import time

import requests

API = "https://api.cyhub.ai/v1"
HEADERS = {"Authorization": "Bearer YOUR_API_KEY"}

body = {
    "model": "flux3",
    "settings": {
        "mode": "t2v",
        "prompt": "Лиса бежит сквозь утренний туман, под лапами хрустят ветки",
        "aspect_ratio": "16:9",
        "duration": 8,
    },
}

response = requests.post(f"{API}/tasks", json=body, headers=HEADERS, timeout=60)
response.raise_for_status()
task = response.json()
while task["status"] in ("queued", "running"):
    time.sleep(5)
    task = requests.get(f"{API}/tasks/{task['id']}", headers=HEADERS, timeout=30).json()
print(task["status"], task["result"])
```

```javascript
const API = "https://api.cyhub.ai/v1";
const HEADERS = { Authorization: "Bearer YOUR_API_KEY", "Content-Type": "application/json" };

const body = {
  "model": "flux3",
  "settings": {
    "mode": "t2v",
    "prompt": "Лиса бежит сквозь утренний туман, под лапами хрустят ветки",
    "aspect_ratio": "16:9",
    "duration": 8
  }
};

async function main() {
  let response = await fetch(`${API}/tasks`, { method: "POST", headers: HEADERS, body: JSON.stringify(body) });
  if (!response.ok) throw new Error(await response.text());
  let task = await response.json();
  while (task.status === "queued" || task.status === "running") {
    await new Promise((resolve) => setTimeout(resolve, 5000));
    response = await fetch(`${API}/tasks/${task.id}`, { headers: HEADERS });
    task = await response.json();
  }
  console.log(task.status, task.result);
}

main();
```

[Get a key](https://cyhub.ai/cabinet/keys)

## Price before the run

Prices as of 15.10.2026: from 43 ₽. POST /v1/price shows the exact price of your settings.

Send the same settings to POST /v1/price: the response shows the price of the run without charging you.

```bash
curl -X POST "https://api.cyhub.ai/v1/price" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  --data '{
  "model": "flux3",
  "settings": {
    "mode": "t2v",
    "prompt": "Лиса бежит сквозь утренний туман, под лапами хрустят ветки",
    "aspect_ratio": "16:9",
    "duration": 8
  }
}'
```

- amount_minor: the price of the run in minor units (kopecks for rubles)
- currency: the wallet currency
- available_minor: how much your balance has for new tasks right now

## <a id="t2v"></a>From a description

> A video from text alone, no files are sent.

Value of the mode field: `t2v`

Price in this mode from 43 ₽.

### Parameters

Model parameters go inside settings. Omitted optional fields take their default values.

#### `prompt` (Required)

What happens in the video: the scene, the camera movement, the sounds. Spoken lines and on-screen text can be described too.

- Type: String
- Minimum characters: 1
- Maximum characters: 5000

#### `render` (Optional)

A full video or a draft. A draft is faster, always HD and costs about a third of a full video. A draft cannot be rebuilt in full quality through the API: a full video is a new generation, and the scene may come out differently.

- Type: String
- Allowed values: `full`, `draft`
- Default: `"full"`

#### `resolution` (Optional)

Quality of a full video: HD or Full HD, Full HD costs more. A draft is always HD, this field does not apply to it.

- Type: String
- Allowed values: `hd`, `fhd` (Full HD)
- Default: `"hd"`

#### `aspect_ratio` (Optional)

Aspect ratio. Auto: the model picks it itself, from the frames or the source clip.

- Type: String
- Allowed values: `auto`, `21:9`, `2:1`, `16:9`, `4:3`, `1:1`, `3:4`, `9:16`
- Default: `"9:16"`

#### `audio` (Optional)

With sound or silent. The model writes speech, effects and ambience in the same run, the sound is not billed separately.

- Type: String
- Allowed values: `on` (With sound), `off` (Silent)
- Default: `"on"`

#### `duration` (Optional)

Video length in seconds, 5 to 20. The price is per second, so it grows with the length.

- Type: Integer
- Minimum: 5
- Maximum: 20
- Default: `5`

Parameters not listed here are not accepted: the response is 422 unknown_setting.

> The API sets these settings itself, do not send them: `files_as_is` = `true`

### Request example

Send this JSON to POST /v1/tasks with your API key. To check the price first, send the same JSON to POST /v1/price.

A video from a description

```json
{
  "model": "flux3",
  "settings": {
    "mode": "t2v",
    "prompt": "Лиса бежит сквозь утренний туман, под лапами хрустят ветки",
    "aspect_ratio": "16:9",
    "duration": 8
  }
}
```

A draft to check the idea

```json
{
  "model": "flux3",
  "settings": {
    "mode": "t2v",
    "prompt": "Бармен подбрасывает шейкер, ловит его за спиной и говорит: «Ваш коктейль»",
    "render": "draft",
    "duration": 6
  }
}
```

The price is calculated when the task is accepted, currency `RUB`.

[Complete generation example](https://api.cyhub.ai/docs/generations.md?lang=en)

### Output

- One MP4 video, 24 frames per second, with sound unless it is turned off.
- Generation takes 1 to 10 minutes depending on length and quality.

| Kind | Formats | How many | Note |
|---|---|---|---|
| `video` | mp4 | 1 |  |

A finished task as GET /v1/tasks/{id} returns it (some fields left out). The caption may sit on the task or on a single file and may be empty; the model picks the file name.

```json
{
  "id": "7c9e6679-7425-40de-944b-e07fc1f90ae7",
  "status": "succeeded",
  "finished_at": "2026-10-01T12:03:41+00:00",
  "result": {
    "caption": "Caption of the result: the model and its settings",
    "texts": [],
    "files_expire_at": "2026-10-08T12:03:41+00:00",
    "files_expired": false,
    "artifacts": [
      {
        "index": 0,
        "kind": "video",
        "filename": "video.mp4",
        "size": 12582912,
        "caption": "",
        "download_path": "/v1/tasks/7c9e6679-7425-40de-944b-e07fc1f90ae7/artifacts/0"
      }
    ]
  }
}
```

[How to read the result and download files](https://api.cyhub.ai/docs/tasks.md?lang=en#result)

## <a id="i2v"></a>From frames

> Your pictures become frames of the video: one opens the clip, two set the start and the end, more than two are spread evenly from start to finish.

Value of the mode field: `i2v`

Price in this mode from 43 ₽.

### Parameters

Model parameters go inside settings. Omitted optional fields take their default values.

#### `prompt` (Required)

What happens in the video: the scene, the camera movement, the sounds. Spoken lines and on-screen text can be described too.

- Type: String
- Minimum characters: 1
- Maximum characters: 5000

#### `render` (Optional)

A full video or a draft. A draft is faster, always HD and costs about a third of a full video. A draft cannot be rebuilt in full quality through the API: a full video is a new generation, and the scene may come out differently.

- Type: String
- Allowed values: `full`, `draft`
- Default: `"full"`

#### `resolution` (Optional)

Quality of a full video: HD or Full HD, Full HD costs more. A draft is always HD, this field does not apply to it.

- Type: String
- Allowed values: `hd`, `fhd` (Full HD)
- Default: `"hd"`

#### `aspect_ratio` (Optional)

Aspect ratio. Auto by default: the model picks it from your frames.

- Type: String
- Allowed values: `auto`, `21:9`, `2:1`, `16:9`, `4:3`, `1:1`, `3:4`, `9:16`
- Default: `"auto"`

#### `audio` (Optional)

With sound or silent. The model writes speech, effects and ambience in the same run, the sound is not billed separately.

- Type: String
- Allowed values: `on` (With sound), `off` (Silent)
- Default: `"on"`

#### `duration` (Optional)

Video length in seconds, 5 to 20. The price is per second, so it grows with the length.

- Type: Integer
- Minimum: 5
- Maximum: 20
- Default: `5`

#### `image_urls` (Required)

One to ten frame URLs, in order.

- Type: List (String, uri)
- Maximum items: 10

Parameters not listed here are not accepted: the response is 422 unknown_setting.

> The API sets these settings itself, do not send them: `files_as_is` = `true`

### Input

- Frames are URLs of JPEG, PNG or WebP images, each at least 256 by 256 pixels.

| Field | Accepts | Formats | Files | File size up to |
|---|---|---|---|---|
| `image_urls` | Images | jpeg, jpg, png, webp | 10 |  |

[How to send files](https://api.cyhub.ai/docs/files.md?lang=en)

### Request example

Send this JSON to POST /v1/tasks with your API key. To check the price first, send the same JSON to POST /v1/price.

Animate a frame

```json
{
  "model": "flux3",
  "settings": {
    "mode": "i2v",
    "prompt": "Камера медленно наезжает, листья шевелятся на ветру",
    "image_urls": [
      "https://example.com/first-frame.jpg"
    ]
  }
}
```

Start and end

```json
{
  "model": "flux3",
  "settings": {
    "mode": "i2v",
    "prompt": "Бутон распускается в цветок, капли росы блестят на солнце",
    "aspect_ratio": "1:1",
    "duration": 6,
    "image_urls": [
      "https://example.com/bud.png",
      "https://example.com/flower.png"
    ]
  }
}
```

The price is calculated when the task is accepted, currency `RUB`.

[Complete generation example](https://api.cyhub.ai/docs/generations.md?lang=en)

### Output

- One MP4 video, 24 frames per second, with sound unless it is turned off.
- Generation takes 1 to 10 minutes depending on length and quality.

| Kind | Formats | How many | Note |
|---|---|---|---|
| `video` | mp4 | 1 |  |

A finished task as GET /v1/tasks/{id} returns it (some fields left out). The caption may sit on the task or on a single file and may be empty; the model picks the file name.

```json
{
  "id": "7c9e6679-7425-40de-944b-e07fc1f90ae7",
  "status": "succeeded",
  "finished_at": "2026-10-01T12:03:41+00:00",
  "result": {
    "caption": "Caption of the result: the model and its settings",
    "texts": [],
    "files_expire_at": "2026-10-08T12:03:41+00:00",
    "files_expired": false,
    "artifacts": [
      {
        "index": 0,
        "kind": "video",
        "filename": "video.mp4",
        "size": 12582912,
        "caption": "",
        "download_path": "/v1/tasks/7c9e6679-7425-40de-944b-e07fc1f90ae7/artifacts/0"
      }
    ]
  }
}
```

[How to read the result and download files](https://api.cyhub.ai/docs/tasks.md?lang=en#result)

## <a id="v2v"></a>Video continuation

> The model continues your clip from its last frames. The source is not part of the result. Noticeably more expensive than the other modes.

Value of the mode field: `v2v`

Price in this mode from 86 ₽, with a 1 s file.

### Parameters

Model parameters go inside settings. Omitted optional fields take their default values.

#### `prompt` (Required)

What happens in the video: the scene, the camera movement, the sounds. Spoken lines and on-screen text can be described too.

- Type: String
- Minimum characters: 1
- Maximum characters: 5000

#### `render` (Optional)

A full video or a draft. A draft is faster, always HD and costs about a third of a full video. A draft cannot be rebuilt in full quality through the API: a full video is a new generation, and the scene may come out differently.

- Type: String
- Allowed values: `full`, `draft`
- Default: `"full"`

#### `resolution` (Optional)

Quality of a full video: HD or Full HD, Full HD costs more. A draft is always HD, this field does not apply to it.

- Type: String
- Allowed values: `hd`, `fhd` (Full HD)
- Default: `"hd"`

#### `aspect_ratio` (Optional)

Aspect ratio. Auto by default: the continuation keeps the aspect ratio of the source clip, so the join is clean.

- Type: String
- Allowed values: `auto`, `21:9`, `2:1`, `16:9`, `4:3`, `1:1`, `3:4`, `9:16`
- Default: `"auto"`

#### `audio` (Optional)

With sound or silent. The model writes speech, effects and ambience in the same run, the sound is not billed separately.

- Type: String
- Allowed values: `on` (With sound), `off` (Silent)
- Default: `"on"`

#### `duration` (Optional)

Video length in seconds, 5 to 15. The price is per second, so it grows with the length.

- Type: Integer
- Minimum: 5
- Maximum: 15
- Default: `5`

#### `video_urls` (Required)

One URL of the MP4 clip to continue.

- Type: List (String, uri)
- Maximum items: 1

Parameters not listed here are not accepted: the response is 422 unknown_setting.

> The API sets these settings itself, do not send them: `files_as_is` = `true`

### Input

- The clip is a URL of an MP4 file up to 50 MB and no longer than 60 seconds. It is sent whole, there is no trimming: cut it beforehand if needed.

| Field | Accepts | Formats | Files | File size up to |
|---|---|---|---|---|
| `video_urls` | Video | mp4 | 1 | 50 MB |

[How to send files](https://api.cyhub.ai/docs/files.md?lang=en)

### Request example

Send this JSON to POST /v1/tasks with your API key. To check the price first, send the same JSON to POST /v1/price.

Continue a clip

```json
{
  "model": "flux3",
  "settings": {
    "mode": "v2v",
    "prompt": "Машина уходит в поворот, из-под колёс летит гравий, камера догоняет её",
    "duration": 5,
    "video_urls": [
      "https://example.com/clip.mp4"
    ]
  }
}
```

The price is calculated when the task is accepted, currency `RUB`.

[Complete generation example](https://api.cyhub.ai/docs/generations.md?lang=en)

### Output

- One MP4 video, 24 frames per second, with sound unless it is turned off.
- Generation takes 1 to 10 minutes depending on length and quality.

| Kind | Formats | How many | Note |
|---|---|---|---|
| `video` | mp4 | 1 |  |

A finished task as GET /v1/tasks/{id} returns it (some fields left out). The caption may sit on the task or on a single file and may be empty; the model picks the file name.

```json
{
  "id": "7c9e6679-7425-40de-944b-e07fc1f90ae7",
  "status": "succeeded",
  "finished_at": "2026-10-01T12:03:41+00:00",
  "result": {
    "caption": "Caption of the result: the model and its settings",
    "texts": [],
    "files_expire_at": "2026-10-08T12:03:41+00:00",
    "files_expired": false,
    "artifacts": [
      {
        "index": 0,
        "kind": "video",
        "filename": "video.mp4",
        "size": 12582912,
        "caption": "",
        "download_path": "/v1/tasks/7c9e6679-7425-40de-944b-e07fc1f90ae7/artifacts/0"
      }
    ]
  }
}
```

[How to read the result and download files](https://api.cyhub.ai/docs/tasks.md?lang=en#result)

## See also

- [FLUX 3: features and prices](https://api.cyhub.ai/models/flux-3)
- Similar models: [Seedance 2.5 API](https://api.cyhub.ai/en/models/seedance-2-5/api.md), [Kling 3.0 API](https://api.cyhub.ai/en/models/kling-3/api.md), [Kling Motion 3.0 API](https://api.cyhub.ai/en/models/kling-motion/api.md), [Veo 3.1 API](https://api.cyhub.ai/en/models/veo-3-1/api.md), [Wan 3.0 API](https://api.cyhub.ai/en/models/wan-3/api.md), [MiniMax H3 (Hailuo 03) API](https://api.cyhub.ai/en/models/minimax-h3/api.md)
- [API documentation](https://api.cyhub.ai/docs.md?lang=en)
- [API errors and how to handle them](https://api.cyhub.ai/docs/errors.md?lang=en)