Flutter

The Flutter SDK wraps the Lean Link SDK in a webview_flutter-backed widget with one named constructor per flow.

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Prerequisites

Before calling any SDK method you need to have completed the backend setup in the Getting Started section:

• Create your Lean application in the developer dashboard to obtain an app_token.
• Authentication — OAuth flow for minting customer-scoped access_tokens.
• Creating a customer — POST /customers/v1 to obtain a customer_id.
• Sandbox testing — test users and mock bank.

This page covers only the client-side SDK integration.

Installation

Add the dependency to your pubspec.yaml:

dependencies:
  lean_sdk_flutter: ^3.0.17

Then install:

flutter pub get

Package brings in webview_flutter, webview_flutter_wkwebview, webview_flutter_android, permission_handler, and url_launcher as transitive dependencies.

Demo

See the /example directory in link-sdk-flutter .

Usage

Instantiate the named constructor for the flow you want to launch and render the widget — for example inside a full-screen route, Dialog, or custom overlay.

import 'package:flutter/material.dart';
import 'package:lean_sdk_flutter/lean_sdk_flutter.dart';

class LeanConnectScreen extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Lean.connect(
        appToken: "<YOUR_APP_TOKEN>",
        customerId: "CUSTOMER_ID",
        permissions: [
          LeanPermissions.identity,
          LeanPermissions.accounts,
          LeanPermissions.balance,
          LeanPermissions.transactions,
        ],
        accessToken: "<CUSTOMER_SCOPED_JWT>",
        isSandbox: true,
        country: LeanCountry.ae,
        language: LeanLanguage.en,
        callback: (LeanResponse response) {
          debugPrint("Status: ${response.status}");
          Navigator.of(context).pop();
        },
      ),
    );
  }
}

Shared constructor parameters

Every Lean.* constructor accepts these parameters in addition to its flow-specific fields:

Available methods

Each flow has a dedicated named constructor on the Lean widget. Flow-specific parameter names use camelCase (e.g. customerId, paymentDestinationId).

Lean.connect()

Link a bank account for data access (and optionally payments).

Required: appToken, customerId, permissions.

Lean.connect(
  appToken: "<YOUR_APP_TOKEN>",
  customerId: "CUSTOMER_ID",
  permissions: [
    LeanPermissions.identity,
    LeanPermissions.accounts,
    LeanPermissions.balance,
    LeanPermissions.transactions,
  ],
  // Optional:
  accessTo: null,
  accessFrom: null,
  accessToken: null,
  bankIdentifier: null,
  failRedirectUrl: null,
  successRedirectUrl: null,
  paymentDestinationId: null,
  customerMetadata: null,
  showConsentExplanation: null,
  destinationAlias: null,
  destinationAvatar: null,
  callback: (response) { /* ... */ },
);

Customisation

Pass a Map<String, String> to the customization parameter. Keys match the field names in Customisation (snake_case):

Lean.connect(
  appToken: "<YOUR_APP_TOKEN>",
  customerId: "CUSTOMER_ID",
  permissions: [LeanPermissions.identity, LeanPermissions.accounts],
  customization: {
    "theme_color": "#0080ff",
    "button_text_color": "#ffffff",
    "link_color": "#0080ff",
    "overlay_color": "rgba(0, 0, 0, 0.8)",
    "button_border_radius": "8",
    "dialog_mode": "contained",
    // Dark-mode overrides
    "theme_color_dark": "#1a1a1a",
    "button_text_color_dark": "#ffffff",
  },
);

Language

Pass language: LeanLanguage.ar to any constructor for Arabic (right-to-left). Omit for English.

Bank-list and account-selection shortcuts

Pass bankIdentifier to skip the bank-selection screen (see Create your own bank list). Pass accountId on Lean.pay(...) to skip the payment-source-selection screen.

Troubleshooting

iOS permissions

permission_handler handles camera and mic permissions requested by certain flows. Add the relevant Info.plist usage descriptions when your integration uses those flows:

<key>NSCameraUsageDescription</key>
<string>...</string>
<key>NSMicrophoneUsageDescription</key>
<string>...</string>

Android WebView rendering

The SDK uses webview_flutter_android. If you see rendering issues, confirm hardware acceleration is enabled for the host Activity and that android:usesCleartextTraffic isn't blocking the loader domain.

Related

• Authentication
• Creating a customer
• Config reference
• Flows reference
• Open Finance
• Customisation
• LinkSDK statuses
• Create your own bank list