API

SigCleaner REST API documentation.

Each successful \/api\/clean request deducts 1 processing credit from your account balance.

Method: Background removal

      POST https://sigclean.io/api/clean
    

Authorization

Authorization: Bearer YOUR_API_KEY

Request parameters

Parameter	Type	Required	Description
`file`	multipart file	One of two	PNG, JPG, or PDF image. If the PDF is multi-page — only the first page is processed.
`url`	string	One of two	Direct image URL
`type`	string	No	`json` (default) — return a JSON response with a file link `webp` — return a binary WebP file with a transparent background `png` — return a binary PNG file with a transparent background
`extract`	string	No	Extraction of a specific element. Empty by default — standard background removal. `signature` — keep only the handwritten signature, removing everything else. `stamp` — keep only the stamp, removing everything else.
`aggressive`	boolean	No	Aggressive text removal. When set to `1` (`true`), aggressively removes all printed letters, numbers, and straight black form lines, leaving only the specified element.
`mode`	string	No	Processing mode. Default — `standard`. `standard` — Standard mode. Works well with high-quality images. The result is as close to the original as possible. `advanced` — Smart mode. More thorough processing; suitable for low-quality images or those with many unwanted elements.
`name`	string	No	Displayed file name in the "My Files" list. Saved upon successful processing.

Response: `type=json`

{
  "status": "ok",
  "uuid": "550e8400-e29b-41d4-a716-446655440000",
  "url":   "https://sigclean.io/api/file/550e8400-e29b-41d4-a716-446655440000",
  "remaining": 9,
  "limit": 10
}

Response: `type=webp`

Returns a WebP binary file with a transparent background. Content-Type: image/webp.

Response: `type=png`

Returns a PNG binary file with a transparent background. Content-Type: image/png.

cURL Examples

curl -X POST https://sigclean.io/api/clean \
  -H "Authorization: Bearer YOUR_KEY" \
  -F "file=@stamp.jpg" \
  -F "type=json"

curl -X POST https://sigclean.io/api/clean \
  -H "Authorization: Bearer YOUR_KEY" \
  -F "file=@stamp.jpg" \
  -F "type=png" \
  --output result.png

curl -X POST https://sigclean.io/api/clean \
  -H "Authorization: Bearer YOUR_KEY" \
  -F "file=@stamp.jpg" \
  -F "type=webp" \
  --output result.webp

Signature extraction with aggressive text removal:

curl -X POST https://sigclean.io/api/clean \
  -H "Authorization: Bearer YOUR_KEY" \
  -F "file=@document.jpg" \
  -F "type=png" \
  -F "extract=signature" \
  -F "aggressive=1" \
  --output signature.png

Smart processing mode:

curl -X POST https://sigclean.io/api/clean \
  -H "Authorization: Bearer YOUR_KEY" \
  -F "file=@stamp.jpg" \
  -F "type=png" \
  -F "mode=advanced" \
  --output result.png

Download result

      GET https://sigclean.io/api/file/{uuid}
    

Method: File list

      GET https://sigclean.io/api/files
    

Returns a list of all successfully processed files belonging to the current user. Files are accessible via the link /api/file/{uuid}.

Authorization

Authorization: Bearer YOUR_API_KEY

Response

{
  "status": "ok",
  "files": [
    {
      "uuid":       "550e8400-e29b-41d4-a716-446655440000",
      "name":       "stamp.jpg",
      "url":        "https://sigclean.io/api/file/550e8400-e29b-41d4-a716-446655440000",
      "created_at": "2026-07-01T10:00:00Z",
      "expires_at": "2027-07-01T10:00:00Z"
    }
  ]
}

Field	Type	Description
`uuid`	string	Unique file ID
`name`	string \| null	Displayed file name (from the `name` parameter in `\/api\/clean` or after renaming)
`url`	string	Direct download link for the file (WebP)
`created_at`	string (ISO 8601)	File creation date and time (UTC)
`expires_at`	string \| null	Storage expiration date (UTC).

cURL Example

curl https://sigclean.io/api/files \
  -H "Authorization: Bearer YOUR_KEY"

Method: Delete file

      POST https://sigclean.io/api/files/delete
    

Permanently deletes a file from the server. The file must belong to the current user.

Authorization

Authorization: Bearer YOUR_API_KEY

Request body `application\/json`

Parameter	Type	Required	Description
`uuid`	string	Yes	File UUID from the `\/api\/clean` or `\/api\/files` response.

Response

{ "status": "ok" }

Error codes

Code	Description
`401`	Unauthorized
`404`	File not found or does not belong to the user
`422`	Missing or invalid `uuid`

cURL Example

curl -X POST https://sigclean.io/api/files/delete \
  -H "Authorization: Bearer YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{"uuid":"550e8400-e29b-41d4-a716-446655440000"}'

Method: Rename file

      POST https://sigclean.io/api/files/rename
    

Changes the displayed file name. The file must belong to the current user.

Authorization

Authorization: Bearer YOUR_API_KEY

Request body `application\/json`

Parameter	Type	Required	Description
`uuid`	string	Yes	File UUID from the `\/api\/clean` or `\/api\/files` response.
`name`	string	Yes	New displayed file name (up to 255 characters).

Response

{
  "status": "ok",
  "name": "stamp.jpg"
}

Error codes

Code	Description
`401`	Unauthorized
`404`	File not found or does not belong to the user
`422`	Missing or invalid `uuid` \/ `name`

cURL Example

curl -X POST https://sigclean.io/api/files/rename \
  -H "Authorization: Bearer YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{"uuid":"550e8400-e29b-41d4-a716-446655440000","name":"stamp.jpg"}'

API Key Management

You must log in to manage keys.

API

Method: Background removal

Authorization

Request parameters

Response: type=json

Response: type=webp

Response: type=png

cURL Examples

Download result

Method: File list

Authorization

Response

cURL Example

Method: Delete file

Authorization

Request body application\/json

Response

Error codes

cURL Example

Method: Rename file

Authorization

Request body application\/json

Response

Error codes

cURL Example

API Key Management

Response: `type=json`

Response: `type=webp`

Response: `type=png`

Request body `application\/json`

Request body `application\/json`