1. Initiate request: POST /mfcentral/cas/summary or /mfcentral/cas/detail
2. Validate OTP: POST /mfcentral/validate-otp
3. Download PDF: GET /mfcentral/cas/document

• INVALID_PAN • PAN format incorrect
• MISSING_MOBILE • Mobile is required
• INVALID_OTP • OTP incorrect
• OTP_EXPIRED • OTP expired
• SESSION_NOT_FOUND • Invalid/expired session
• ACCESS_TOKEN_EXPIRED • Download token expired

Sandbox: https://api-sandbox.example.com

curl -X POST https://api-sandbox.example.com/mfcentral/cas/summary   -H "Content-Type: application/json"   -H "Authorization: Bearer your_test_token"   -H "X-API-Key: your_test_api_key"   -d '{
    "pan": "AAAAA0000A",
    "mobile": "9876543210",
    "email": "test@example.com"
  }'

1. Initiate request (optional date range): POST /mfcentral/cas/detail
2. Validate OTP: POST /mfcentral/validate-otp
3. Download PDF: GET /mfcentral/cas/document

• INVALID_DATE_RANGE • From date must be before to date
• NO_TRANSACTIONS_FOUND • No taxable transactions in range
• INVALID_OTP / OTP_EXPIRED
• SESSION_NOT_FOUND
• ACCESS_TOKEN_EXPIRED

Sandbox: https://api-sandbox.example.com

curl -X POST https://api-sandbox.example.com/mfcentral/cas/detail   -H "Content-Type: application/json"   -H "Authorization: Bearer your_test_token"   -H "X-API-Key: your_test_api_key"   -d '{
    "pan": "AAAAA0000A",
    "mobile": "9876543210",
    "email": "test@example.com",
    "from_date": "2024-04-01",
    "to_date": "2025-03-31"
  }'

The LARK NPM Package provides a seamless way to integrate loan eligibility checking into your React/Vue.js/Next.js applications. It offers a complete loan origination flow with mutual fund portfolio backing.

npm install lark-sdk-multi

import LoanEligibilitySDK from 'lark-sdk-multi';

const sdk = new LoanEligibilitySDK({
  apiKey: 'your-api-key',
  apiSecret: 'your-api-secret',
  phoneNumber: '+919876543210'
});

Install the LARK SDK in your React project

npm install lark-sdk-multi

yarn add lark-sdk-multi

"lark-sdk-multi": "file:../path/to/sdk"

LARK SDK is available for multiple platforms to fit your development needs

npm install lark-sdk-multi

# or with yarn
yarn add lark-sdk-multi

import LoanEligibilitySDK from 'lark-sdk-multi';

const sdk = new LoanEligibilitySDK({
  apiKey: 'your-api-key',
  apiSecret: 'your-api-secret',
  phoneNumber: '+919876543210'
});

await sdk.initialize({
  partnerId: 'your-partner-id'
});

sdk.openEligibilityCheck('inline');

Configure your environment and SDK credentials

VITE_SDK_KEY=your_sdk_key_here
VITE_SDK_SECRET=your_sdk_secret_here
VITE_PARTNER_ID=your_partner_id_here
VITE_API_URL=https://api.larkfinserv.in

interface PartnerConfig {
  apiKey: string;
  apiSecret: string;
  partnerId?: string;
  phoneNumber?: string;
  environment?: 'sandbox' | 'production';
  theme?: ThemeConfig;
}

Complete integration example with React hooks and state management

import React, { useState, useEffect } from 'react';
import LoanEligibilitySDK from 'lark-sdk-multi';
import type { SDKEvent } from 'lark-sdk-multi/src/types';

function App() {
  const [sdk, setSdk] = useState<LoanEligibilitySDK | null>(null);
  const [status, setStatus] = useState<'idle' | 'loading' | 'success' | 'error'>('idle');
  const [phoneNumber, setPhoneNumber] = useState('');

  useEffect(() => {
    if (phoneNumber.length !== 10) return;

    const sdkInstance = new LoanEligibilitySDK({
      apiKey: process.env.REACT_APP_SDK_KEY!,
      apiSecret: process.env.REACT_APP_SDK_SECRET!,
      phoneNumber: `+91${phoneNumber}`,
    });

    // Event handlers
    sdkInstance.on('INITIATED', () => setStatus('loading'));
    sdkInstance.on('READY', () => setStatus('success'));
    sdkInstance.on('ELIGIBILITY_RESULT', (event: SDKEvent) => {
      console.log('Result:', event.data);
    });
    sdkInstance.on('ERROR', (event: SDKEvent) => {
      console.error('Error:', event.data);
      setStatus('error');
    });

    setSdk(sdkInstance);
  }, [phoneNumber]);

  const handleStartCheck = async () => {
    if (!sdk) return;

    try {
      await sdk.initialize({
        partnerId: process.env.REACT_APP_PARTNER_ID!,
        apiKey: process.env.REACT_APP_SDK_KEY!,
        apiSecret: process.env.REACT_APP_SDK_SECRET!,
      });

      sdk.openEligibilityCheck('inline');
    } catch (error) {
      console.error('Failed to start check:', error);
      setStatus('error');
    }
  };

  return (
    <div>
      <input
        type="tel"
        value={phoneNumber}
        onChange={(e) => setPhoneNumber(e.target.value.replace(/\D/g, ''))}
        placeholder="Enter 10-digit mobile number"
        maxLength={10}
      />
      
      <button
        onClick={handleStartCheck}
        disabled={phoneNumber.length !== 10 || status === 'loading'}
      >
        {status === 'loading' ? 'Loading...' : 'Start Eligibility Check'}
      </button>
      
      <div id="loan-eligibility-sdk"></div>
    </div>
  );
}

Complete API documentation for the LARK SDK

new LoanEligibilitySDK(config: PartnerConfig)

Real-world examples and practical use cases

const sdk = new LoanEligibilitySDK({
  apiKey: 'your-api-key',
  apiSecret: 'your-api-secret',
  phoneNumber: '+919876543210',
  theme: {
    primaryColor: '#007bff',
    secondaryColor: '#6c757d',
    fontFamily: 'Inter, sans-serif',
    borderRadius: '8px'
  }
});

// Detect mobile and adjust SDK behavior
const isMobile = window.innerWidth < 768;

// Use popup for mobile, inline for desktop
sdk.openEligibilityCheck(isMobile ? 'popup' : 'inline');

// Listen for orientation changes
window.addEventListener('orientationchange', () => {
  const isNowMobile = window.innerWidth < 768;
  if (isNowMobile !== isMobile) {
    sdk.closeFrame();
    sdk.openEligibilityCheck(isNowMobile ? 'popup' : 'inline');
  }
});

sdk.on('ERROR', (event) => {
  const error = event.data.error;
  
  switch (error.code) {
    case 'NETWORK_ERROR':
      showErrorMessage('Network connection issue.');
      break;
    case 'VALIDATION_ERROR':
      showErrorMessage(`Validation failed: ${error.message}`);
      break;
    case 'AUTH_ERROR':
      showErrorMessage('Authentication failed.');
      break;
    default:
      showErrorMessage('An unexpected error occurred.');
  }
});

Common issues and solutions

Add dependency in pubspec.yaml:

dependencies:
  larkfinserv_flutter_sdk: ^0.0.3

Install and import:

flutter pub get
import 'package:larkfinserv_flutter_sdk/larkfinserv_flutter_sdk.dart';

final sdk = LarkFinServSDK();
await sdk.initialize(PartnerConfig(
  apiKey: 'your_api_key',
  apiSecret: 'your_api_secret',
  environment: 'sandbox',
));
await sdk.openEligibilityCheck(SDKMode.popup);

• initialize(PartnerConfig) → Future<void>
• openEligibilityCheck(SDKMode) → Future<void>
• createWebViewController() → WebViewController
• events → Stream<SDKEvent>
• dispose()

Use PartnerConfig (portal theme takes precedence):

PartnerConfig(
  apiKey: 'sandbox_api_key',
  apiSecret: 'sandbox_api_secret',
  environment: 'sandbox',
  theme: ThemeConfig(
    primaryColor: '#2196F3',
    secondaryColor: '#FF9800',
    name: 'MyFinance App',
  ),
)

Inline widget with event handling:

sdk.events.listen((event) {
  switch (event.type) {
    case SDKEventType.eligibilityResult:
      // handle result
      break;
    case SDKEventType.error:
      // handle error
      break;
    default:
      break;
  }
});

• ready • SDK ready
• initiated • Flow started
• eligibilityResult • Result available
• error • Error occurred
• close • UI closed
• closeFrame • WebView closed

• INVALID_CONFIG • Check keys/secrets
• INITIALIZATION_FAILED • Verify network/credentials
• SDK_NOT_INITIALIZED • Call initialize()
• URL_LAUNCH_FAILED, WEBVIEW_ERROR

iOS: add ATS and LSApplicationQueriesSchemes. Android: INTERNET and ACCESS_NETWORK_STATE; queries for http/https. Web: ensure CSP allows inline.

https://sdk-backend.larkfinserv.com

application/json

Core Endpoints

{
    "id": "74c3355b-87d3-4aae-9f9a-cb479aceb287",
    "first_name": "AWNISH",
    "last_name": "DUBEY",
    "phone_no": "+919958989595",
    "email": "919958989595@placeholder.com",
    "roles": ["customer"],
    "status": "active",
    "dob": "2002-02-02",
    "partner_id": "2a3b5cde-2506-4cc3-af65-ae033a7beff1",
    "device_info": {
        "partnerId": "2a3b5cde-2506-4cc3-af65-ae033a7beff1",
        "phone_otp": null,
        "timestamp": "2025-08-14T13:20:36.990Z",
        "createdVia": "SDK_INIT",
        "is_phone_verified": "true",
        "phone_otp_expires_at": null
    },
    "pan": "GQNPD9571A",
    "reported_issues": [],
    "created_at": "2025-08-14T13:20:37.068Z",
    "updated_at": "2025-08-14T13:20:46.074Z",
    "partner": {
        "id": "2a3b5cde-2506-4cc3-af65-ae033a7beff1",
        "company_name": "",
        "status": "active",
        "partner_type": "other"
    },
    "portfolio": {
        "userId": "74c3355b-87d3-4aae-9f9a-cb479aceb287",
        "pan": "GQNPD9571A",
        "reportedIssues": [],
        "portfolio": null,
        "hasPortfolio": false
    }
}

Typical flow:

1. Initialize session: /loan-sdk/init
2. Verify phone via OTP
3. Verify PAN and fetch portfolio
4. Get offers and submit application
5. Track status and manage loans