Flutter SDK

Supported Connections

Connection Type	Supported	Notes
TCP/IP (Wi‑Fi)*	✔ (Android & iOS)	Recommended for stable and fast setup. Uses terminal IP + port.
Bluetooth	✔ (Android only)	Requires pairing with Android device first. Not supported on iOS.
App‑to‑App*	✔ (Android only)	Uses Intent/WebSocket communication with NamiPay app installed.
Serial (USB CDC)	❌	Not supported on mobile platforms. Limited to desktop SDKs (Java, .NET).

Step 1: Initialize SDK

config = await ConfigManager.getConfiguration();

Step 2: Connect to Terminal

TCP/IP (Wi‑Fi)

await tcpSocket.connectTCP(ip, port, cashRegisterNumber);

Bluetooth (Android only)

await _bluetoothService.connectDevice(device, cashRegisterNumber);

App‑to‑App (Android only)

await _webSocketService.connect(cashRegisterNumber);

Step 3: Prepare Transaction

final String ecrRef =
  "${config.cashRegisterNumber}${EncryptionUtil.getSixDigitUniqueNumber()}";

String signature = EncryptionUtil.getSha256Hash(
  config.ecrUnique,
  config.terminalId!,
);

Step 4: Create Request

final String reqData =
  "${EncryptionUtil.getFormattedDateTime()};${amount};$printFlag!;$ecrRef!";

Step 5: Convert to HEX

final String hexReqData = EncryptionUtil.stringToHex(reqData);

Step 6: Perform Transaction

await tcpSocket.doTransaction(
  reqData: hexReqData,
  txnType: txnType,
  signature: signature,
  listener: this,
);

Step 7: Handle Response

TCP/IP → handled via tcpSocket.connectTCP
Bluetooth → handled via _bluetoothService.connectDevice
App‑to‑App → handled via _webSocketService.connect

Flow Summary

Initialize SDK → Connect (Wi‑Fi / Bluetooth / App‑to‑App) → Prepare Transaction → Create Request → Convert to HEX → Perform Transaction → Handle Response