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
ParameterTypeRequiredDescription
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.
basic — light cleaning. Removes only the background, leaving everything else.
standard — standard cleaning (Ultra). Removes the background and unnecessary elements, such as text. Suitable for most cases.
advanced — deep cleaning (Ultra). Image processing using intelligent algorithms. Suitable for low-quality files or those with many extraneous elements. In this mode, you can select an extraction object or aggressive removal of extraneous 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

Deep cleaning:

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" } ] }
FieldTypeDescription
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
ParameterTypeRequiredDescription
uuid string Yes File UUID from the \/api\/clean or \/api\/files response.
Response
{ "status": "ok" }
Error codes
CodeDescription
401Unauthorized
404File not found or does not belong to the user
422Missing 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
ParameterTypeRequiredDescription
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
CodeDescription
401Unauthorized
404File not found or does not belong to the user
422Missing 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

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