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Flux 3 Extend Video

Integrate

Model id blackforestlabs/flux-3/extend-video
# 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/blackforestlabs/flux-3/extend-video?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",
    "video": "https://content.doitong.com/video/showcase/v3/gen_fox_cartoon.mp4"
  }'

# 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"

This request: $8.20 8,200 API credits Run it on this page

Get API key
Black Forest Labs Video to Video Native audio4K outputLipsync5–20 sup to 2160p #stylized#transform

Continues an existing MP4 clip past its last frame, with resolutions up to 2160p

Made on Doitong

Public works made with Flux 3 New 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

Continuation instructions for the video, taking the source clip's last frames as the starting point.

•required video_url
Drop a file, or

URL pointing to an MP4 shorter than 15 seconds and smaller than 50 MB, used as the source video.

duration auto

Video length: specify seconds or select `auto` for a model-chosen duration.

aspect_ratio default auto

Output video's aspect ratio; `auto` delegates the choice to the model.

resolution default 720p

Output resolution, with pixel dimensions determined by aspect ratio. Finishing uses the video upsampler for `1080p`, `1440p` (2K), and `2160p` (4K).

Advanced safety_tolerance
default 2

Video safety tolerance uses a scale whose most permissive setting is 4 and whose strictest setting is 0.

POST /run/blackforestlabs/flux-3/extend-video?wait=20 quote → $8.20
# 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/blackforestlabs/flux-3/extend-video?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",
    "video": "https://content.doitong.com/video/showcase/v3/gen_fox_cartoon.mp4"
  }'

# 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"

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 Extend Video

Extends a source video from `video_url` (MP4, under 50 MB and under 15 seconds), guided by a `prompt` describing what happens next. `duration` is `auto` or 5 to 19 seconds. `resolution` ranges from 720p to 2160p, and audio generation is on by default. `safety_tolerance` goes from 0 to 4.

Parameters

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

NameType DefaultAllowed Description
promptrequired
Typestring
Continuation instructions for the video, taking the source clip's last frames as the starting point.
aspect_ratiooptional
Typeenum
Defaultauto
auto21:92:116:94:31:13:49:16
Output video's aspect ratio; `auto` delegates the choice to the model.
resolutionoptional
Typeenum
Default720p
720p1080p1440p2160p
Output resolution, with pixel dimensions determined by aspect ratio. Finishing uses the video upsampler for `1080p`, `1440p` (2K), and `2160p` (4K).
durationoptional
Typeenum
Defaultauto
auto5678910111213141516171819
+1 more20
Video length: specify seconds or select `auto` for a model-chosen duration.
generate_audiooptional
Typeboolean
Defaulttrue
Controls whether the video includes generated audio.
safety_toleranceoptional
Typeinteger
Default2
0 – 4
Video safety tolerance uses a scale whose most permissive setting is 4 and whose strictest setting is 0.
video_urlrequired video
Typeurl · video
URL pointing to an MP4 shorter than 15 seconds and smaller than 50 MB, used as the source video.
required Canonical name, also accepted

File parameters take a public https:// URL, a data: URI up to 10 MB, or the file_url of an upload. Files

Output

GET /requests/req_8k2m4q7x1z9c3v5b6n0p2r4t
{
  "id": "req_8k2m4q7x1z9c3v5b6n0p2r4t",
  "object": "request",
  "model": "blackforestlabs/flux-3/extend-video",
  "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": 8200,
    "usd": "8.20",
    "charged": 8200,
    "refunded": 0
  },
  "input": {
    "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field",
    "video_url": "https://content.doitong.com/video/showcase/v3/gen_fox_cartoon.mp4"
  },
  "output": {
    "video": {
      "url": "https://content.doitong.com/dev-api/2026/10/20/req_8k2m4q7x1z9c3v5b6n0p2r4t/0-output.mp4",
      "content_type": "video/mp4",
      "file_name": "0-output.mp4",
      "file_size": 1843200
    },
    "seed": 42
  },
  "outputs": [
    {
      "type": "video",
      "url": "https://content.doitong.com/dev-api/2026/10/20/req_8k2m4q7x1z9c3v5b6n0p2r4t/0-output.mp4",
      "content_type": "video/mp4",
      "file_size": 1843200,
      "width": 1280,
      "height": 720,
      "duration": 5,
      "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"
  }
}
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
video
object {url, content_type, file_name, file_size}Video produced by the model.
seed
integerSeed value used during generation.

More models: Video to Video

For AI agents: this page as Markdown is at https://doitong.com/developers/models/blackforestlabs/flux-3/extend-video.md. All models and guides: https://doitong.com/developers/llms.txt