Generates a short-form video from a text prompt (T2V) or a text prompt + starting image (I2V). Submits, polls, and returns the final video URL. Default model is 'grok-imagine-t2v' (fast, 4-6 cr/s, with built-in KIE -> fal.ai fallback). Use list_video_models for the full lineup with credit cost per second. I2V models (e.g. 'grok-imagine-i2v', 'seedance-pro-i2v') require a public `imageUrl`. Video generation can take 30s to several minutes; this tool polls with up to an 8-minute budget.
## Model selection guide for videos (when the user does not specify a model)
Default: `grok-imagine-t2v` (4-6 cr/s, fast, has KIE -> fal.ai fallback for redundancy. Best general-purpose).
Pick a different model when the prompt has these signals:
- "highest quality" / "premium" / broadcast / commercial -> `veo3.1-quality` or `veo3-quality` (Google's flagship, fixed 350-560 cr for 8s, 3-5 min)
- "fast premium" / quick high-quality -> `veo3-fast` or `veo3.1-fast` (84 cr fixed for 8s)
- Cinematic camera moves / dolly / pan -> `seedance-pro-t2v` (3-10 cr/s) or `kling-3.0-pro-t2v` (26 cr/s)
- Realistic human motion / faces -> `hailuo-2.3-pro-i2v` (I2V, supply imageUrl)
- Talking head / lip sync -> `kling-avatar-pro` (23 cr/s) or `infinitalk` (5-17 cr/s)
- Anime / stylized / fantasy -> `wan-2.7-t2v`
- NSFW / adult -> `wan-22-nsfw-i2v` (I2V only; auto-tags adult)
- Animate this exact image -> any I2V variant (`grok-imagine-i2v`, `seedance-pro-i2v`, `hailuo-2.3-pro-i2v`)
- First + last frame interpolation -> `seedance-pro-i2v` with both `imageUrl` + `endImageUrl`
- Cheapest test -> `hailuo-2.0-standard` @ 512p (3 cr/s, ~18 cr for 6s) or `grok-imagine-t2v` @ 480p (4 cr/s, ~24 cr for 6s)
- Clip 12-15s -> `grok-imagine-t2v` (accepts up to 15s)
- True 4K -> `kling-3.0-4k-t2v` (94 cr/s, expensive but native 4K)
**Audio in generated video:** `grok-imagine-t2v`, `seedance-pro-t2v`, and the VEO 3.x family include audio at base cost (no surcharge). Kling 2.6 and Kling 3.0 are the outliers — they price audio as a +50-100% surcharge (Kling 2.6 doubles the cost, Kling 3.0 Pro adds ~46%). Default to Grok / Seedance / VEO when sound matters and you don't want to think about audio pricing.
**Cost framing:** resolution and duration drive cost more than model choice. A 6-second 480p Grok generation costs ~24 cr; the same prompt at 1080p Seedance 2 is ~858 cr (35x more). Pick the lowest acceptable resolution + duration first.
**For I2V models:** `imageUrl` is required. For first+last-frame models, pass `endImageUrl` too.
Ask the user only when:
- Single generation would cost more than 100 credits and they haven't confirmed
- They asked for "the best" with no other signal; surface 2-3 options with cost ranges