API reference/POST /sticker

Die-cut sticker with outline

Cut out the subject and add a configurable outline — iMessage/WhatsApp/Telegram-ready. Perfect for sticker packs and chat apps.

POSThttps://useknockout--api.modal.run/sticker

Parameters

Send as multipart/form-data unless noted otherwise.

filerequiredfile—Image to process. JPG, PNG, WebP, HEIC. Up to 10 MB and 4096×4096.
stroke_widthint 0-10016Outline thickness in pixels. 0 = no outline (same as /remove).
stroke_colorstring#FFFFFFHex color of the outline.
paddingint32Transparent padding in pixels around the outlined subject.

Request

curl -X POST "https://useknockout--api.modal.run/sticker" \
  -H "Authorization: Bearer $TOKEN" \
  -F "file=@cat.jpg" \
  -F "stroke_width=24" -F "stroke_color=#FFFFFF" \
  -o out.png

Response

HTTP/1.1 200 OK
content-type: image/png
content-length: 254312
x-knockout-latency: 184
x-knockout-model: BiRefNet
x-ratelimit-limit: 60
x-ratelimit-remaining: 59

Errors

401unauthorized—Missing or invalid token.
402payment_required—Free tier exhausted. Add a card to continue.
413payload_too_large—Image exceeds 10 MB or 4096×4096.
422no_subject_detected—Foreground could not be isolated from background.
429rate_limit_exceeded—Slow down. Retry-After header tells you when.
500internal_error—Something broke on our side. Include request_id when reporting.
Every error response also includes a request_id in the JSON body. Quote it when reporting issues.
← POST /maskPOST /outline →