MAmagichourhq
Video Projects

Character Replace

Changed on

What this API does

Create the same Character Replace you can make in the browser, but programmatically, so you can automate it, run it at scale, or connect it to your own app or workflow.

Good for

  • Automation and batch processing
  • Adding character replace into apps, pipelines, or tools

How it works (3 steps)

  1. Upload your inputs (video, image, or audio) with Generate Upload URLs and copy the file_path.
  2. Send a request to create a character replace job with the basic fields.
  3. Check the job status until it's complete, then download the result from downloads.

Key options

  • Inputs: usually a file, sometimes a YouTube link, depending on project type
  • Resolution: output size and plan requirements vary by workflow and model. Some workflows derive output size from the input video.
  • Extra fields: e.g. face_swap_mode, start_seconds/end_seconds, or a text prompt

Cost
Credits are charged when the job is queued (credits_charged in the response). Tools billed per frame charge an estimate and settle to the frames that actually render once the job finishes; tools billed per second charge the final amount upfront. Failed jobs are refunded.

For detailed examples, see the product page.

post/v1/character-replace

Request

  • Base URL
    https://api.magichour.ai
  • URL
    https://api.magichour.ai/v1/character-replace
  • Auth
    HTTP bearer

Request body

namestring

Give your video a custom name for easy identification.

start_secondsnumber float

Start time of your clip (seconds). Must be ≥ 0.

end_secondsnumber float required

End time of your clip (seconds). Must be greater than start_seconds.

model'wan-animate' | 'kling-3.0' | 'minimax-h3'

Model to use. Defaults to wan-animate.

  • wan-animate: 480p, 720p. Supports points subject selection.
  • kling-3.0: 720p, 1080p. Clips of 3–10 seconds in replace mode or 3–30 seconds in animate mode. Picks the main person automatically, so points are rejected.
  • minimax-h3: 480p, 720p, 1080p. Clips of 1–60 seconds in replace mode or 1–60 seconds in animate mode. Subject points are replace-only; animate with selection_mode point returns 422, and with auto or no selection_mode the points are ignored.
resolution'480p' | '720p' | '1080p'

Output video resolution. Must be supported by model. Defaults to the lowest resolution available on your plan for that model.

Example request

{
  "name": "My Character Replace video",
  "end_seconds": 5,
  "model": "wan-animate",
  "resolution": "480p",
  "assets": {
    "video_file_path": "api-assets/id/1234.mp4",
    "image_file_path": "api-assets/id/5678.png"
  },
  "style": {
    "mode": "replace",
    "selection_mode": "auto"
  }
}

Response

Success

idstring required

Unique ID of the video. Use it with the Get video Project API to fetch status and downloads.

credits_chargedinteger required

The amount of credits deducted from your account to generate the video. If the status is not 'complete', this value is an estimate and may be adjusted upon completion based on the actual FPS of the output video.

If video generation fails, credits will be refunded, and this field will be updated to include the refund.

Example response

{
  "id": "cuid-example",
  "credits_charged": 450
}

Changes

  • d3e045aa65afRevision changes
    • info

      added the new optional request property /

    • info

      added the new minimax-h3 enum value to the request property

  • 6e3bb11fd050Revision changes
    • info

      added the new optional request property

    • info

      added the new 1080p enum value to the request property