Biometric payments on Android POS

What is WinkPay

WinkPay isn't a separate Wink — it's a packaging of the Wink biometric identity stack tailored for Android POS hardware. Underneath, every SDK call resolves to one or more Wink Core API calls. On top, the SDK adds:

• Native customer-display UI — face / palm capture views, card-picker, payment confirmation, MFA + consent dialogs.
• Dual-display routing — auto-targets the customer screen on terminals with one.
• Felix EMV integration — chip-and-PIN tap flow optionally combined with biometric check-in.
• Capture tuning — per-device-class face-ratio defaults, palm overrides, rotation knobs for handhelds with offset sensors.
• POS-only ergonomics — age-restriction merchant override, external-token mode for processors that own the charge, lite registration for low-friction onboarding.

Where to next

Pick the closest match to what you're building:

How a checkout flows

End-to-end, a face-checkout transaction on a WinkPay-enabled terminal looks like this:

1. POS hands off — your app calls winkPay.startPayment(request, callback) with the order amount + tender id, then launches the customer-display Activity via createNativeIntent(...).
2. SDK runs capture — customer-display shows the face-capture view, runs liveness, falls back to palm if face fails (1.4.9+). All on-device.
3. Wink Cloud identifies — the SDK posts the captured frame to Wink's auth APIs; on success returns a winkTag + a list of the customer's saved cards.
4. Card picker + MFA — if multiple cards, the customer picks one on the display; MFA + consent dialogs fire if the merchant config requires them.
5. Charge — either WinkPay charges via its payment rails (default) or returns external tokens for the host to process (returnExternalTokens = true).
6. Result callback — onSuccess fires on the main thread with the transaction id + amount. Your POS prints the receipt.

The SDK Quickstart shows the full 30-line Kotlin integration that wires all of this.

Supported terminals

The SDK targets arm64-v8a Android, minSdk = 24. Reference deployments on:

• Sunmi T3 Pro — dual-display terminal; WinkPay drives the customer screen with face / palm capture while the merchant retains the operator UI.
• PAX A360 — single-display countertop terminal; face-only checkout with EMV combo via Felix.
• Landi — handheld with palm support; rotationAngle = 90 needed for the palm sensor orientation.
• Elo — kiosk-class terminal; face capture at customer-stands-back distance (minFaceRatio ≈ 0.30).

Other arm64-v8a Android terminals work out of the box; see Prerequisites for the constraints.

Latest release

Current SDK: 1.5.0 — public API stabilised, capture tuning knobs, per-modality (face/palm) overrides, lite palm preview path. Direct link: Download & install. Per-version notes live in the SDK Changelog.