MiniMax H3 Recast

Endpoint

POST https://api.roasos.com/v1/video-edit/h3-max-recast

Send your API key as a bearer token. The key needs the scope api:write. Every paid request also needs an Idempotency-Key header.

The envelope fields quote_only, quote_id, webhook_url and wait_timeout_seconds behave the same on each model endpoint. Refer to Jobs and Quotes and credits.

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

The unit is one source_second. Pricing key: h3-max-recast.

The credits come from the roasOS pricing table. No other field changes the price. To get the exact price of your request, send it with quote_only: true first.

Modes

• edit

Provider endpoints: minimax/h3-max/recast.

Request fields

The schema is strict. A field that is not in this table gets 400 unsupported_option. The field names are the roasOS role names. One role has one name in every family.

Media

This endpoint accepts these media roles:

• 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

Every other role is 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 gets 400 unsupported_option.

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

These catalog entries describe omitted inputs, pinned values and source constraints. They do not imply that the provider accepts every listed field.

• 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

The result kind is video. Always present: url.

{
  "data": {
    "id": "gen_…",
    "kind": "video",
    "model": "h3-max-recast",
    "status": "completed",
    "result": {
      "url": "https://cdn.roasos.com/workspaces/ws_01/result"
    }
  }
}

The files are immutable objects on https://cdn.roasos.com. A result URL is a valid media input for your next request.

Example

The three steps are always the same: quote, run, poll.

# 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. Same body, same Idempotency-Key, quote_id in place 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_...", "status": "queued", "credits_reserved": 18 } }

# 3. Poll, then read the result.
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

• llms.txt for this model — the same facts as one plain-text file for an agent.
• GET https://api.roasos.com/v1/catalog/h3-max-recast — the machine-readable form: enums, defaults, limits and prices. Refer to the API reference.
• Jobs — how to poll a job and read its result.
• Provider endpoints: minimax/h3-max/recast.