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What is Proof On/Off Ramp?

Proof is a platform for crypto on-ramp (buy) and off-ramp (sell). Partners embed a single widget and get full fiat ↔ crypto exchange functionality for their users — including KYC, card payments, Apple Pay, and Google Pay. Proof handles all the complex parts:
  • Signature generation and wallet routing
  • KYC orchestration via SumSub
  • Payment processing and status tracking
  • Callback processing and reconciliation
You only need to request a session and embed the widget.

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Architecture

Your Frontend  →  Proof Proxy API  →  Widget + Payments + KYC
1

Onboard with Proof

Send us your company name, domain, and email. We set up your integration manually and send you a client_token.
2

Request a widget session

Call POST /widget/session from your frontend. Proof returns all parameters needed to launch the widget.
3

Embed the widget

Load the widget script and call proofWidget.run() with the session parameters. The widget handles KYC and payment inside an iframe.
4

Track transaction status

Poll GET /widget/transactions/{id} or subscribe via WebSocket to get real-time status updates.

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Supported Features

FeatureDetails
On-ramp (buy)Fiat → USDT via card, Apple Pay, Google Pay
Off-ramp (sell)USDT → EUR/USD fiat payout to card
KYCBuilt-in document upload + liveness check
MobileiOS WKWebView, Android Chrome Custom Tabs
Status trackingPolling API + WebSocket