# MiniMax H3 Recast (video-edit)

> MiniMax H3 Recast replaces the main people in a source video with new people from reference photos. The output keeps the motion, the gestures, the camera, the shot timing and the soundtrack of the source. The output length is the source length.

Status: roasOS API v1.1. Catalog `model-catalog@2026-10-06.v5`, pricing `customer-pricing@2026-11-05.v15`. The endpoint `POST /v1/video-edit/h3-max-recast` is live. `POST /v1/generations` has no `video-edit` type, so this endpoint is the only path to this model.

## Endpoint
POST https://api.roasos.com/v1/video-edit/h3-max-recast
Auth: Authorization: Bearer roasos_sk_… (scope api:write). Idempotency-Key required. quote_only / quote_id / webhook_url as in https://docs.roasos.com/llms.txt.

## Good at
Put your own cast into an ad that works. Send `video_url` (5 to 30 seconds, MP4, no single shot longer than 15 seconds) and 1 to 4 new people. Send one photo for each person in `references`. An `avatar_id` adds one person: the front portrait of the saved avatar. The new people replace the main people of the source from left to right, in this order: your references, then the avatar. Each new person is in every shot where the original person is.

## Pricing
Unit: source_second. Pricing key: `h3-max-recast`.

| request | credits |
|---|---|
| `5s_source_768p` | 18 |
| `5s_source_1080p` | 27 |
| `10s_source_768p` | 36 |
| `10s_source_1080p` | 54 |
| `30s_source_768p` | 108 |
| `30s_source_1080p` | 162 |

Credits come from the roasOS pricing table (`MODEL_COSTS`) through the catalog. No other field changes the price.

## Modes
- `edit`
Provider endpoints: `minimax/h3-max/recast`.

## Request fields
| field | type | required | default | rule |
|---|---|---|---|---|
| `avatar_id` | string | no | — | UUID |
| `enhance_realism` | boolean | no | `false` | — |
| `prompt` | string | no | — | ≤ 10,000 characters |
| `quote_id` | string | no | — | UUID |
| `quote_only` | boolean | no | `false` | — |
| `references` | string[] | no | — | ≤ 4 items |
| `resolution` | enum | no | `1080p` | `768p`, `1080p` |
| `seed` | integer | no | — | 0–2147483647 |
| `video_url` | string | yes | — | https URL; ≤ 4,096 characters |
| `wait_timeout_seconds` | integer | no | `0` | 0–60 |
| `webhook_url` | string | no | — | https URL; ≤ 4,096 characters |

The schema is strict: a field that is not in this table returns `400 unsupported_option`. Field names are the roasOS role names, one name per role across every family.

## Media
- `avatar_id` — identity; the saved character reference sheet, with a derived portrait only where the model requires a single face or source frame
- `references` — style and appearance references
- `video_url` — the source video

| role | items | max size | content types | duration |
|---|---|---|---|---|
| `references` | ≤ 4 | 10 MB | `image/jpeg`, `image/png`, `image/webp` | — |
| `video_url` | ≤ 1 | 100 MB | `video/mp4` | 5–30 s |

- Refused: `elements`, `product_id`, `product_images`, `reference_images`, `image_url`, `end_image_url`, `scene_id`, `scene_image`, `video_urls`, `audio_urls`, `audio_url`, `voice_id`. A refused role returns `400 unsupported_option`.
- Every URL must be an immutable object on `https://cdn.roasos.com/…` that your workspace owns; any other URL is `400 reference_media_not_workspace_owned`. Upload with `POST /v1/uploads` (direct POST of the bytes to `put_url`, or a `source_url` import), then use the returned CDN URL.

## Prompt
Limit 10,000 characters. The prompt is optional.
- Use it to say who becomes whom: "The woman on the left becomes the person in the second photo."
- Use it to say what else must stay or change: "Keep her red jacket."
- Do not ask for a new shot, a new camera move or a different length.

## Not exposed
- `enable_safety_checker`: pinned to `provider default (on); never sent`.
- `duration_seconds`: pinned to `the output follows the source clip`.
- `aspect_ratio`: pinned to `the output keeps the source framing`.
- `generate_audio`: pinned to `the output keeps the source sound`.
- `negative_prompt`: not accepted by this public endpoint.

## Result
Result kind `video`. Always present: `url`.
```json
{ "data": { "id": "gen_…", "kind": "video", "model": "h3-max-recast", "status": "completed", "result": {"url":"https://cdn.roasos.com/workspaces/ws_01/result"} } }
```
Files live on `https://cdn.roasos.com` and are immutable; a result URL can be a media input to the next call. Poll `GET /v1/jobs/{id}/status` → `{ id, status, updated_at }`, then `GET /v1/jobs/{id}/result` (`409 run_not_completed` until the job is `completed`, `failed` or `canceled`). Statuses: `queued → processing → completed | failed | canceled`.

## Example
```bash
# 1. quote — nothing is spent
curl -X POST https://api.roasos.com/v1/video-edit/h3-max-recast \
  -H "Authorization: Bearer roasos_sk_live_…" \
  -H "Idempotency-Key: 0f1c9e2a-h3-max-recast-0001" \
  -H "Content-Type: application/json" \
  -d '{"quote_only":true,"video_url":"https://cdn.roasos.com/workspaces/ws_01/uploads/video_url.mp4"}'
# → 200 { "data": { "kind": "quote", "quote_id": "q_7Hk…", "credits": 18, "expires_at": "…", "confirmation": { "model": "h3-max-recast", "example": "5s_source_768p" } } }

# 2. run — the same body and the same Idempotency-Key, quote_id instead of quote_only
curl -X POST https://api.roasos.com/v1/video-edit/h3-max-recast \
  -H "Authorization: Bearer roasos_sk_live_…" \
  -H "Idempotency-Key: 0f1c9e2a-h3-max-recast-0001" \
  -H "Content-Type: application/json" \
  -d '{"quote_id":"q_7Hk…","video_url":"https://cdn.roasos.com/workspaces/ws_01/uploads/video_url.mp4"}'
# → 201 { "data": { "id": "gen_…", "kind": "video", "model": "h3-max-recast", "status": "queued", "credits_reserved": 18, "links": { "status": "/v1/jobs/gen_…/status", "result": "/v1/jobs/gen_…/result" } } }

# 3. poll
curl https://api.roasos.com/v1/jobs/gen_…/status -H "Authorization: Bearer roasos_sk_live_…"
curl https://api.roasos.com/v1/jobs/gen_…/result -H "Authorization: Bearer roasos_sk_live_…"
```

## Today
`POST /v1/video-edit/h3-max-recast` with `video_url`, `references`, `avatar_id`, `prompt`, `resolution` (768p|1080p, default 1080p), `enhance_realism` (more natural skin and better blending, off by default) and `seed`.

## See also
https://docs.roasos.com/models/video-edit/h3-max-recast · https://api.roasos.com/v1/catalog/video-edit/h3-max-recast · minimax/h3-max/recast