GET

/v1/schemas/fal/video/blackforestlabs/flux-3/extend-video/draft

Accept:

kind inputactivity videohash d8521423…extracted Aug 6, 2026version currentsource upstream spec ↗

field	recorded source
schema	Source linked above. Source trace `cf6915bbadb50e552aebff8ef7d93b739ee31993136605752feea7a051bdf051` { "fetchedAt": 1785992534, "extractorVersion": "1", "verifiedAt": null }

Request body

6 properties · 2 required · 0 $defs

property	type	description	constraints
video_url*	string	URL or data URI of the source MP4, at most 50 MiB.
prompt*	string	The text prompt describing the draft video.
safety_tolerance	integer	The safety tolerance level for the generated video. 0 is the strictest and 4 is the most permissive.	0 ≤ n ≤ 4 · default: 2
aspect_ratio	enum	Aspect ratio of the generated draft. `auto` lets the model choose.	auto \| 21:9 \| 2:1 \| 16:9 \| 4:3 \| 1:1 · +2 more · default: "auto"
generate_audio	boolean	Whether to generate audio for the draft video.	default: true
duration	enum	Draft duration in whole seconds from 5 through 20, or `auto`.	auto \| 5 \| 6 \| 7 \| 8 \| 9 · +11 more · default: "auto"

Validate a payload

before you spend tokens

shell

$ curl -X POST https://modelschemas.com/v1/validate \
    -d '{"provider":"fal","endpointId":"blackforestlabs/flux-3/extend-video/draft","payload":{…}}'
→ {"valid": false, "errors": [{"path": "#", "keyword": "required", …}]}