FLUX 3 Video API reference

Everything you need to call FLUX 3 Video from your code. Base URL https://cheapergen.com/api/v1. Try it first in the playground.

Authentication

Create a key in Dashboard → API keys and send it as a bearer token. Keep keys server-side.

export CHEAPERGEN_API_KEY="cg_live_…"

# every request
Authorization: Bearer $CHEAPERGEN_API_KEY

FLUX 3 Video Text to Video API

POST/api/v1/run/bfl/flux-3-video/text-to-video

Submits an asynchronous job and returns 202 with a generation id. Poll GET /api/v1/generations/{id} or pass webhook_url. See job lifecycle.

Input parameters

Name	Type	Description	Affects price
`prompt`required	string	Describe the shot: subject, action, camera movement, lighting and style.	No
`aspect_ratio`	string (enum)	Output image shape. Values: 16:9 · 9:16 · 1:1 · 4:3 · 3:4 · 21:9 · 2:1 Default: 16:9	Yes
`duration`	integer	Length of the generated clip in seconds (5–20s). You pay per second. Range: 5–20s Default: 5	Yes
`generate_audio`	boolean	Generate synchronized sound, ambience and dialogue. No extra cost. Default: true	No
`webhook_url`	string (URL)	Optional. We POST the finished generation here, signed with your webhook secret. Webhooks	No

Request

curl -X POST https://cheapergen.com/api/v1/run/bfl/flux-3-video/text-to-video \
  -H "Authorization: Bearer $CHEAPERGEN_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "prompt": "A hot-air balloon drifts over Cappadocia at sunrise, the burner roars, the camera rises alongside the basket",
  "aspect_ratio": "16:9",
  "duration": 5
}'

import os, time, requests

API = "https://cheapergen.com/api/v1"
headers = {"Authorization": f"Bearer {os.environ['CHEAPERGEN_API_KEY']}"}

# 1. Submit the job
job = requests.post(f"{API}/run/bfl/flux-3-video/text-to-video", headers=headers, json={
    "prompt": "A hot-air balloon drifts over Cappadocia at sunrise, the burner roars, the camera rises alongside the basket",
    "aspect_ratio": "16:9",
    "duration": 5
}).json()

# 2. Poll until it finishes (or pass "webhook_url" and skip polling)
while job["status"] in ("queued", "running"):
    time.sleep(3)
    job = requests.get(f"{API}/generations/{job['id']}", headers=headers).json()

print(job["status"], job["output"]["video"]["url"] if job["status"] == "succeeded" else job["error"])

const API = "https://cheapergen.com/api/v1";
const headers = {
  Authorization: `Bearer ${process.env.CHEAPERGEN_API_KEY}`,
  "Content-Type": "application/json",
};

// 1. Submit the job
let job = await fetch(`${API}/run/bfl/flux-3-video/text-to-video`, {
  method: "POST",
  headers,
  body: JSON.stringify({
    "prompt": "A hot-air balloon drifts over Cappadocia at sunrise, the burner roars, the camera rises alongside the basket",
    "aspect_ratio": "16:9",
    "duration": 5
  }),
}).then((r) => r.json());

// 2. Poll until it finishes (or pass webhook_url and skip polling)
while (job.status === "queued" || job.status === "running") {
  await new Promise((r) => setTimeout(r, 3000));
  job = await fetch(`${API}/generations/${job.id}`, { headers }).then((r) => r.json());
}

console.log(job.status === "succeeded" ? job.output.video.url : job.error);

Response

{
  "id": "gen_8c2QmX1nq0k4",
  "object": "generation",
  "model": "bfl/flux-3-video",
  "endpoint": "bfl/flux-3-video/text-to-video",
  "mode": "text-to-video",
  "status": "queued",
  "input": {
    "prompt": "A hot-air balloon drifts over Cappadocia at sunrise, the burner roars, the camera rises alongside the basket",
    "aspect_ratio": "16:9",
    "duration": 5
  },
  "output": null,
  "error": null,
  "cost": {
    "amount_usd": 0.2255,
    "currency": "usd",
    "estimated": true,
    "official_usd": null,
    "saved_usd": null
  },
  "source": "api",
  "started_at": null,
  "completed_at": null,
  "urls": {
    "get": "https://cheapergen.com/api/v1/generations/gen_8c2QmX1nq0k4",
    "cancel": "https://cheapergen.com/api/v1/generations/gen_8c2QmX1nq0k4/cancel"
  },
  "created_at": "2026-10-15T09:21:04Z"
}

{
  "id": "gen_8c2QmX1nq0k4",
  "object": "generation",
  "model": "bfl/flux-3-video",
  "endpoint": "bfl/flux-3-video/text-to-video",
  "mode": "text-to-video",
  "status": "succeeded",
  "input": {
    "prompt": "A hot-air balloon drifts over Cappadocia at sunrise, the burner roars, the camera rises alongside the basket",
    "aspect_ratio": "16:9",
    "duration": 5
  },
  "output": {
    "video": {
      "url": "https://cdn.cheapergen.ai/outputs/gen_8c2Q.mp4",
      "content_type": "video/mp4",
      "duration": 5,
      "width": 1280,
      "height": 720
    }
  },
  "error": null,
  "cost": {
    "amount_usd": 0.2255,
    "currency": "usd",
    "estimated": false,
    "official_usd": 0.264,
    "saved_usd": 0.0385
  },
  "source": "api",
  "created_at": "2026-10-15T09:21:04Z",
  "started_at": "2026-10-15T09:21:06Z",
  "completed_at": "2026-10-15T09:22:31Z"
}

FLUX 3 Video Image to Video API

POST/api/v1/run/bfl/flux-3-video/image-to-video

Submits an asynchronous job and returns 202 with a generation id. Poll GET /api/v1/generations/{id} or pass webhook_url. See job lifecycle.

Input parameters

Name	Type	Description	Affects price
`prompt`required	string	Describe the shot: subject, action, camera movement, lighting and style.	No
`image_url`required	string (URL)	Image used as the opening frame. JPG/PNG/WebP, URL or upload.	No
`end_image_url`	string (URL)	Optional closing frame — the model animates between the two.	No
`duration`	integer	Length of the generated clip in seconds (5–20s). You pay per second. Range: 5–20s Default: 5	Yes
`generate_audio`	boolean	Generate synchronized sound, ambience and dialogue. No extra cost. Default: true	No
`webhook_url`	string (URL)	Optional. We POST the finished generation here, signed with your webhook secret. Webhooks	No

Request

curl -X POST https://cheapergen.com/api/v1/run/bfl/flux-3-video/image-to-video \
  -H "Authorization: Bearer $CHEAPERGEN_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "prompt": "Slow push-in as the flower opens from bud to full bloom",
  "image_url": "https://cdn.cheapergen.ai/samples/portrait.jpg",
  "duration": 5
}'

import os, time, requests

API = "https://cheapergen.com/api/v1"
headers = {"Authorization": f"Bearer {os.environ['CHEAPERGEN_API_KEY']}"}

# 1. Submit the job
job = requests.post(f"{API}/run/bfl/flux-3-video/image-to-video", headers=headers, json={
    "prompt": "Slow push-in as the flower opens from bud to full bloom",
    "image_url": "https://cdn.cheapergen.ai/samples/portrait.jpg",
    "duration": 5
}).json()

# 2. Poll until it finishes (or pass "webhook_url" and skip polling)
while job["status"] in ("queued", "running"):
    time.sleep(3)
    job = requests.get(f"{API}/generations/{job['id']}", headers=headers).json()

print(job["status"], job["output"]["video"]["url"] if job["status"] == "succeeded" else job["error"])

const API = "https://cheapergen.com/api/v1";
const headers = {
  Authorization: `Bearer ${process.env.CHEAPERGEN_API_KEY}`,
  "Content-Type": "application/json",
};

// 1. Submit the job
let job = await fetch(`${API}/run/bfl/flux-3-video/image-to-video`, {
  method: "POST",
  headers,
  body: JSON.stringify({
    "prompt": "Slow push-in as the flower opens from bud to full bloom",
    "image_url": "https://cdn.cheapergen.ai/samples/portrait.jpg",
    "duration": 5
  }),
}).then((r) => r.json());

// 2. Poll until it finishes (or pass webhook_url and skip polling)
while (job.status === "queued" || job.status === "running") {
  await new Promise((r) => setTimeout(r, 3000));
  job = await fetch(`${API}/generations/${job.id}`, { headers }).then((r) => r.json());
}

console.log(job.status === "succeeded" ? job.output.video.url : job.error);

Response

{
  "id": "gen_8c2QmX1nq0k4",
  "object": "generation",
  "model": "bfl/flux-3-video",
  "endpoint": "bfl/flux-3-video/image-to-video",
  "mode": "image-to-video",
  "status": "queued",
  "input": {
    "prompt": "Slow push-in as the flower opens from bud to full bloom",
    "image_url": "https://cdn.cheapergen.ai/samples/portrait.jpg",
    "duration": 5
  },
  "output": null,
  "error": null,
  "cost": {
    "amount_usd": 0.2255,
    "currency": "usd",
    "estimated": true,
    "official_usd": null,
    "saved_usd": null
  },
  "source": "api",
  "started_at": null,
  "completed_at": null,
  "urls": {
    "get": "https://cheapergen.com/api/v1/generations/gen_8c2QmX1nq0k4",
    "cancel": "https://cheapergen.com/api/v1/generations/gen_8c2QmX1nq0k4/cancel"
  },
  "created_at": "2026-10-15T09:21:04Z"
}

{
  "id": "gen_8c2QmX1nq0k4",
  "object": "generation",
  "model": "bfl/flux-3-video",
  "endpoint": "bfl/flux-3-video/image-to-video",
  "mode": "image-to-video",
  "status": "succeeded",
  "input": {
    "prompt": "Slow push-in as the flower opens from bud to full bloom",
    "image_url": "https://cdn.cheapergen.ai/samples/portrait.jpg",
    "duration": 5
  },
  "output": {
    "video": {
      "url": "https://cdn.cheapergen.ai/outputs/gen_8c2Q.mp4",
      "content_type": "video/mp4",
      "duration": 5,
      "width": 1280,
      "height": 720
    }
  },
  "error": null,
  "cost": {
    "amount_usd": 0.2255,
    "currency": "usd",
    "estimated": false,
    "official_usd": 0.264,
    "saved_usd": 0.0385
  },
  "source": "api",
  "created_at": "2026-10-15T09:21:04Z",
  "started_at": "2026-10-15T09:21:06Z",
  "completed_at": "2026-10-15T09:22:31Z"
}

Get the result

Generations are asynchronous. Poll until status is succeeded, failed or canceled — or pass webhook_url when you submit. Failed generations are refunded automatically.

curl https://cheapergen.com/api/v1/generations/gen_8c2QmX1nq0k4 \
  -H "Authorization: Bearer $CHEAPERGEN_API_KEY"

More: job lifecycle · webhooks · errors

FLUX 3 Video pricing

Pay per second of video. No subscription. Failed generations are refunded automatically.

Tier	Official price	Cheaper Gen.	You save
720p audio included	~~$0.15~~/s	$0.143/s	−5%

Official price: BFL API list price for FLUX 3 Video at 720p ($0.15 per second, audio included). Prices verified 2026-10-16.
1080p and above are not offered yet: our channel's rate there is above BFL's own price.