Welcome to the SDK & Libraries hub. Use this page to decide whether to operate the Terminal Gateway App as a companion or embed the Terminal H2H / C2C SDKs directly in your application.
Choose one track per deployment: run the standalone Gateway App or embed Terminal H2H or C2C SDKs. Mixing Gateway App with SDK integrations on the same device leads to conflicting sessions.
Gateway App
Terminal H2H SDK
Terminal C2C SDK
The Terminal Gateway App is a ready-to-use companion that manages device discovery, firmware, and secure networking. It is used by two integration paths:
- H2H path — The Gateway App relays commands between the Terminal API (HTTP) and physical terminals. Required for BRI/NTT; other providers connect directly.
- C2C path — The Gateway App exposes the Terminal C2C API (HTTP REST) on the local network. Required for BRI/NTT; other providers receive commands directly.
The Terminal H2H SDK provides device connectivity for the H2H integration path. It embeds terminal communication inside your Android or iOS app, replacing the Gateway App as the relay layer.
- Payment API calls are always made via HTTP to the Terminal API — the SDK handles the device side only.
- Recommended when you want staff to stay in a single app workflow with consistent branding.
- Required for BRI/NTT terminals on the H2H path if you choose not to use the Gateway App.
The Terminal C2C SDK provides native method calls as an alternative to the Terminal C2C API (HTTP). Instead of sending REST commands, your app calls SDK methods directly.
- For BRI/NTT terminals, the C2C SDK is the required install — it handles device connectivity.
- For other providers (Cashup, SHC), the C2C SDK is an optional convenience wrapper.
- Ideal for kiosks, custom POS, or any scenario requiring advanced device control and offline resilience.
Sample use cases
Web POS (Gateway App)
Assisted checkout (H2H)
Self-service kiosk (C2C)
A browser-based POS team wants to accept cards without rebuilding their app in native mobile languages.
Choose the Gateway App when your cashier experience already runs on Windows or macOS and you prefer to keep payments outside the browser for compliance, driver management, and quick deployment.
- Operations manage hardware from a single companion app while developers continue shipping updates in web frameworks.
- IT teams can lock down dedicated workstations, separating PCI controls from the POS codebase.
A mobile retail app powers assisted selling inside flagships and pop-ups, and staff expect to stay in one interface during checkout.
Pick H2H SDKs when associates already carry Android or iOS devices and you want them to trigger payments, signature capture, and receipts without switching apps.
- Training is faster: new hires learn one app that covers product lookup, cart building, and tendering.
- Store designers keep consistent branding because payments inherit your app’s look and feel.
A self-service kiosk fleet depends on custom flows, offline tolerance, and tight integration with scanners, printers, and loyalty systems.
Opt for C2C SDKs when you need end-to-end control over every terminal command, from prompting the customer to handling edge cases during outages.
- Engineers can coordinate peripherals, screen content, and payments from one application.
- Support teams define venue-specific fallbacks, such as queueing payments when mall networks are unreliable.
Document the chosen operating model in your runbook so support teams know whether to escalate to Gateway App operators or the dedicated H2H/C2C SDK maintainers.
