Attachments

Attachments let you provide source material for a Mosaic Motion job.

The API accepts up to 10 attachments per job. Each attachment must be a publicly accessible signed URL.

Request shape

{
  "attachments": [
    {
      "url": "https://storage.example.com/signed/reference.png",
      "name": "Hero reference",
      "type": "image",
      "content_type": "image/png"
    }
  ]
}

Fields

Field	Required	Description
url	Yes	Publicly accessible signed URL. Maximum 4096 characters.
name	No	Human readable label. Maximum 240 characters.
type	No	One of image, video, audio, or file.
content_type	No	MIME type hint, such as image/png or video/mp4.

URL requirements

Signed URLs must be reachable by Motion servers without additional headers, cookies, or authentication.

Use URLs with enough time to live for ingestion and generation. For long video files, prefer a generous expiry.

Limits

• Maximum attachments per job: 10.
• Maximum URL length: 4096 characters.
• Maximum attachment name length: 240 characters.
• The API rejects more than 10 attachments with 400 Invalid request.