Video model by Black Forest Labs
FLUX 3 Max API
model: flux-3-max
Call FLUX 3 Max with your KeelRouter API key, the same key you use for every other model. From $0.055 per second, paid per call from a prepaid balance. Failed calls are free.
Pricing
| Option | Price |
|---|---|
| 720p | $0.055 per second |
| 720p 5s | $0.27 per clip |
| 720p 10s | $0.55 per clip |
| 720p 20s | $1.10 per clip |
| 1080p | $0.094 per second |
| 1080p 5s | $0.47 per clip |
| 1080p 10s | $0.94 per clip |
| 1080p 20s | $1.80 per clip |
Call it
Async: POST /v1/video/generations returns a taskId; poll the same path with ?task_id= or pass a callback_url.
curl https://api.keelrouter.com/v1/video/generations \
-H "Authorization: Bearer $KEELROUTER_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"model": "flux-3-max",
"prompt": "A paper boat drifting down a rainy street, slow camera follow",
"resolution": "720p",
"duration": "5"
}'Parameters
| Name | Type | Notes |
|---|---|---|
| model | string | Required. flux-3-max |
| prompt | string | Required. |
| duration | number | Range 5–20. Default 5. |
| resolution | string | One of 720p, 1080p. Default 720p. |
| aspect_ratio | string | One of auto, 21:9, 2:1, 16:9, 4:3, 1:1, 3:4, 9:16. Default auto. |
| first_frame_url | string | |
| last_frame_url | string | |
| keyframes | array | Range …–10. |
| generate_audio | boolean | Default true. |
| reasoning_level | string | One of high, low. Default high. |
| seed | number | |
| callback_url | string | Optional https URL; we POST the result when the task ends |
FAQ
- How much does the FLUX 3 Max API cost on KeelRouter?
- From $0.055 per second. You pay per call from a prepaid USD balance; failed calls are not charged.
- How do I call FLUX 3 Max?
- POST to /v1/video/generations with model "flux-3-max". You get a taskId back; poll the same endpoint with ?task_id= or pass a callback_url.
- Is this the official FLUX 3 Max API?
- No. KeelRouter is an independent API gateway. Requests run on FLUX 3 Max through our upstream providers, and the video model keeps its own safety filters.
- How long are results kept?
- Result files are kept for 30 days, then deleted. Download what you want to keep.
KeelRouter is an independent service and is not affiliated with Black Forest Labs. FLUX 3 Max is a trademark of its owner, used here only to name the model a request runs on.