Black Forest Labs' first video model through one unified API. Up to 20 seconds of 720p or 1080p video with synchronized audio, from a prompt, up to 10 images, or a clip you want to continue. A single REST endpoint, async jobs, and webhooks.
Integrate Flux 3 with a single API call — one key, one unified endpoint, and shared billing across every model on Apiframe.
model: "flux-3" Billing scales with the clip you ask for: 29 credits ($0.29) per second at 720p and 49 credits ($0.49) per second at 1080p, audio included. A 5-second 720p clip is 145 credits ($1.45); a 10-second 1080p clip is 490 credits ($4.90).
Ambient sound, speech, and effects are generated with the video and synchronized to it, at no extra cost. Turn it off with a single flag when you want a silent clip.
Ask for any whole number of seconds from 5 to 20, or let the model choose a length that fits the content.
One image opens the clip pixel for pixel, two set the first and last frame, and three or more become keyframes spread evenly across the timeline.
Pass a finished mp4 as start_video and Flux 3 picks up from its final frames, so you can build sequences well past the 20-second per-generation limit.
Draft mode returns a fast 720p preview at 10 credits ($0.10) per second — roughly a third of the full-quality rate — so you can test prompts before paying for final quality.
Example prompts you can run through the Flux 3 API on Apiframe.
A lighthouse keeper climbs the spiral stairs at dawn, waves crashing below, wind and gulls in the background
A street food vendor plates noodles under warm lamplight, steam rising, sizzle and chatter around the stall
A slow dolly through an empty theatre as the house lights fade up, dust in the beams, distant orchestra tuning
Aerial shot rising over pine forest into low cloud, wind building on the soundtrack
Send a single POST /v2/videos/generate request with your API key to
generate with Flux 3. The call returns a jobId you can poll or
receive via webhook.
curl -X POST https://api.apiframe.ai/v2/videos/generate \
-H "X-API-Key: afk_your_api_key_here" \
-H "Content-Type: application/json" \
-d '{
"prompt": "a cinematic sunrise over a futuristic cityscape, smooth camera push-in",
"model": "flux-3",
"flux3Params": {
"images": [
"https://example.com/input.jpg"
],
"start_video": "https://example.com/input.jpg",
"resolution": "720p",
"generate_audio": true
}
}'import requests
response = requests.post(
"https://api.apiframe.ai/v2/videos/generate",
headers={
"X-API-Key": "afk_your_api_key_here",
"Content-Type": "application/json",
},
json={
"prompt": "a cinematic sunrise over a futuristic cityscape, smooth camera push-in",
"model": "flux-3",
"flux3Params": {
"images": [
"https://example.com/input.jpg"
],
"start_video": "https://example.com/input.jpg",
"resolution": "720p",
"generate_audio": True
}
},
)
print(response.json()) # { "jobId": "...", "status": "QUEUED" }const response = await fetch("https://api.apiframe.ai/v2/videos/generate", {
method: "POST",
headers: {
"X-API-Key": "afk_your_api_key_here",
"Content-Type": "application/json",
},
body: JSON.stringify({
"prompt": "a cinematic sunrise over a futuristic cityscape, smooth camera push-in",
"model": "flux-3",
"flux3Params": {
"images": [
"https://example.com/input.jpg"
],
"start_video": "https://example.com/input.jpg",
"resolution": "720p",
"generate_audio": true
}
}),
});
const { jobId } = await response.json();
console.log(jobId);Generation is asynchronous. A successful submission returns 202 Accepted with a jobId. Poll GET /v2/jobs/{id} (or supply a webhook_url) until the status is COMPLETED; the result field then holds the output URL(s).
{
"jobId": "b2c3d4e5-f6a7-8901-bcde-f23456789012",
"status": "QUEUED"
}curl https://api.apiframe.ai/v2/jobs/JOB_ID \
-H "X-API-Key: afk_your_api_key_here"import requests, time
while True:
job = requests.get(
"https://api.apiframe.ai/v2/jobs/JOB_ID",
headers={"X-API-Key": "afk_your_api_key_here"},
).json()
if job["status"] in ("COMPLETED", "FAILED"):
break
time.sleep(2)
print(job["result"])let job;
do {
await new Promise((r) => setTimeout(r, 2000));
job = await fetch("https://api.apiframe.ai/v2/jobs/JOB_ID", {
headers: { "X-API-Key": "afk_your_api_key_here" },
}).then((r) => r.json());
} while (job.status !== "COMPLETED" && job.status !== "FAILED");
console.log(job.result);Request parameters accepted by the Flux 3 endpoint. Model-specific options are nested under the params object shown below.
| Parameter | Type | Required | Default | Allowed / range | Description |
|---|---|---|---|---|---|
| prompt | string | required | — | — | Text description of what to generate. |
| model | string | required | "flux-3" | "flux-3" | The model identifier for this endpoint. |
| flux3Params.images | string[] (URLs) | optional | — | — | None = text-to-video, one opens the clip, two start and end it, three or more become a storyboard (pick a duration). |
| flux3Params.start_video | string (URL) | optional | — | — | Continue a clip from its final frames. Cannot be combined with images. |
| flux3Params.resolution | string | optional | "720p" | "720p", "1080p" | Resolution |
| flux3Params.generate_audio | boolean | optional | true | — | Synchronized ambient sound, speech, and effects. On by default. |
| flux3Params.draft | boolean | optional | false | — | Fast, low-cost 720p preview for iterating on a prompt. |
Common questions about the Flux 3 API.
Any whole number of seconds from 5 to 20 in a single generation. Omit the duration and the model picks a length that fits your prompt — that request is billed at the 20-second maximum, so pass an explicit duration for exact pricing. To go longer, pass a finished clip as start_video and chain generations together.
It is billed per second of video: 29 credits ($0.29) per second at 720p and 49 credits ($0.49) per second at 1080p, with audio included. Draft previews are 10 credits ($0.10) per second. Continuing an existing video costs 70 credits ($0.70) per second at 720p and 90 credits ($0.90) per second at 1080p. Omitting the duration is billed at the 20-second maximum.
Yes. Synchronized ambient sound, speech, and effects are produced in the same pass as the video and are on by default, at no extra charge. Set generate_audio to false for a silent clip.
Pass images in flux3Params. One image opens the clip as its first frame, shown pixel for pixel. Two images set the start and the end. Three or more (up to 10) act as a storyboard, evenly spaced across the clip — that mode needs an explicit duration.
Yes. Pass its URL as flux3Params.start_video and Flux 3 continues from the final frames. The input must be an mp4 of at most 50MB and 15 seconds, and it cannot be combined with images.
Flux 2 is an image model. Flux 3 is Black Forest Labs’ multimodal model built on their Self-Flow architecture, trained across images, video, and audio, and it outputs video with sound.
720p or 1080p, in 21:9, 2:1, 16:9, 4:3, 1:1, 3:4, or 9:16. Leave the aspect ratio on auto and the model picks one from your prompt and inputs.
Still have questions?
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