qr_flow_sdk #

A Flutter SDK for the QR Flow API — generate static and dynamic QR codes in your app with a single API key.

• Static QR — generated locally, no network call. Supports URL, text, WiFi, vCard, email, SMS, and phone.
• Dynamic QR — API-backed, with a stable redirect URL. Change the destination any time without reprinting.
• QrFlowImage widget — drop-in Widget that renders any QR code with full color and shape customization.

Getting Started #

1. Obtain an API key #

Contact qr-flow.dev or your self-hosted admin dashboard to create a tenant and receive an API key (sk_live_...).

2. Add the dependency #

dependencies:
  qr_flow_sdk: ^0.1.0

3. Initialize #

Call QrFlow.init once at app startup, before any other SDK call.

import 'package:qr_flow_sdk/qr_flow_sdk.dart';

void main() {
  QrFlow.init(apiKey: 'sk_live_YOUR_KEY');
  runApp(const MyApp());
}

Static QR Codes #

Static QR codes are generated entirely on-device — no network request is made.

// URL
final qr = QrFlow.staticQr.url('https://example.com');

// WiFi
final qr = QrFlow.staticQr.wifi(
  ssid: 'MyNetwork',
  password: 'secret',
  encryption: 'WPA',
);

// Contact (vCard)
final qr = QrFlow.staticQr.contact(
  firstName: 'Jane',
  lastName: 'Doe',
  phone: '+1234567890',
  email: 'jane@example.com',
);

// Email
final qr = QrFlow.staticQr.email(
  address: 'support@example.com',
  subject: 'Hello',
);

// SMS
final qr = QrFlow.staticQr.sms(phone: '+1234567890', message: 'Hi!');

// Phone
final qr = QrFlow.staticQr.phone('+1234567890');

// Plain text
final qr = QrFlow.staticQr.text('Hello, World!');

Display it:

QrFlowImage(data: qr.payload, size: 220)

Register it with the API for quota tracking (optional):

final registered = await QrFlow.staticQr.register(qr);
print(registered.id); // server-assigned ID

Dynamic QR Codes #

Dynamic QR codes are managed by the API. The QR image encodes a stable redirect URL; you can update the destination at any time.

// Create
final qr = await QrFlow.dynamicQr.create(
  name: 'Restaurant Menu',
  targetUrl: 'https://restaurant.com/menu',
  type: 'menu', // url | menu | event | custom
);

print(qr.redirectUrl); // encode THIS into the QR image

// Update destination (no reprint needed)
await QrFlow.dynamicQr.update(qr.id, targetUrl: 'https://restaurant.com/menu-v2');

// Toggle active/inactive
await QrFlow.dynamicQr.toggle(qr.id, isActive: false);

// List all
final list = await QrFlow.dynamicQr.list();

// Analytics (last 7 days)
final analytics = await QrFlow.dynamicQr.analytics(qr.id, days: 7);
print('${analytics.totalScans} scans, ${analytics.uniqueScans} unique');

// Delete
await QrFlow.dynamicQr.delete(qr.id);

Display a dynamic QR:

QrFlowImage.dynamic(qr: qr, size: 220)

QrFlowImage Widget #

// Static payload
QrFlowImage(
  data: 'https://example.com',
  size: 200,
  style: const QrStyle(
    foreground: '#1a1a2e',
    background: '#ffffff',
    shape: 'rounded', // 'square' | 'rounded'
  ),
)

// Dynamic QR — auto-encodes qr.redirectUrl
QrFlowImage.dynamic(qr: myDynamicQr, size: 200)

QrStyle #

Usage & Quota #

final usage = await QrFlow.usage();
print('Plan: ${usage.plan}');
print('Static: ${usage.staticUsed} / ${usage.staticLimit ?? "unlimited"}');
print('Dynamic: ${usage.dynamicUsed} / ${usage.dynamicLimit ?? "unlimited"}');

Plan Limits #

Error Handling #

All API calls throw typed exceptions:

try {
  final qr = await QrFlow.dynamicQr.create(
    name: 'My QR',
    targetUrl: 'https://example.com',
  );
} on QrFlowQuotaException catch (e) {
  print('Quota exceeded: ${e.current}/${e.limit}');
} on QrFlowAuthException {
  print('Invalid API key');
} on QrFlowNotFoundException {
  print('QR not found');
} on QrFlowValidationException catch (e) {
  print('Validation error: ${e.message}');
} on QrFlowException catch (e) {
  print('API error (${e.statusCode}): ${e.message}');
}

PayloadGenerator #

Use PayloadGenerator directly to build QR payload strings without creating a StaticQr:

final wifiString = PayloadGenerator.wifi(
  ssid: 'Network',
  password: 'pass',
  encryption: 'WPA',
);

Advanced Configuration #

QrFlow.init(
  apiKey: 'sk_live_xxx',
  baseUrl: 'https://your-self-hosted-api.example.com',
  timeout: const Duration(seconds: 15),
);