curl --request POST \
  --url https://cloud.comfy.org/api/upload/mask \
  --header 'Content-Type: multipart/form-data' \
  --header 'X-API-Key: <api-key>' \
  --form image='@example-file' \
  --form 'original_ref=<string>'

{
  "name": "<string>",
  "subfolder": "<string>",
  "type": "<string>",
  "metadata": {
    "is_mask": true,
    "original_hash": "<string>",
    "mask_type": "<string>",
    "related_files": {
      "mask": "<string>",
      "paint": "<string>",
      "painted": "<string>"
    }
  }
}