feat: Rewrite SDK in TypeScript with full type definitions

[emilio-kariuki]

feat: Rewrite SDK in TypeScript with full type definitions

Summary

Complete rewrite of the IntaSend Node.js SDK from JavaScript to TypeScript, providing full type safety, improved developer experience, and IDE autocompletion.

Changes

New Features

• Full TypeScript source with strict mode enabled
• Strongly typed interfaces for all API payloads (ChargePayload, PayoutPayload, etc.)
• IntelliSense/autocomplete support in modern IDEs
• Type declarations (.d.ts) generated and published automatically

Improvements

• Typed method signatures across all service classes
• Generic send<T>() method on the HTTP client for typed responses
• Cleaner module structure with centralized type definitions

API Coverage

• Collection - M-Pesa STK Push, checkout, payment status
• Payouts - M-Pesa B2C/B2B, bank transfers, airtime, IntaSend transfers
• Wallets - Create, list, get, transactions, intra-transfer, funding
• Refunds - Create, list, get chargebacks

Testing

• 74 unit tests across 6 test suites (Jest + ts-jest)
• Full https module mocking — no network calls required
• Coverage: client init, HTTP layer, collection, payouts, wallets, refunds

Migration

This is a non-breaking change. Existing JavaScript users can continue using const IntaSend = require('intasend-node') without modifications, while TypeScript users gain full type safety.

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Usage Examples

Initialize Client

import IntaSend from 'intasend-node';

// Test mode
const intasend = new IntaSend('ISPubKey_test_xxx', 'ISSecretKey_test_xxx', true);

// Production mode
const intasend = new IntaSend('ISPubKey_live_xxx', 'ISSecretKey_live_xxx', false);

Collection - M-Pesa STK Push

const response = await intasend.collection().mpesaStkPush({
  phone_number: '254712345678',
  name: 'John Doe',
  email: 'john@example.com',
  amount: 100,
  api_ref: 'order-123',
});

Collection - Checkout

const checkout = await intasend.collection().charge({
  first_name: 'John',
  last_name: 'Doe',
  email: 'john@example.com',
  host: 'https://yoursite.com',
  amount: 1000,
  currency: 'KES',
  api_ref: 'order-456',
});
// Redirect customer to checkout.url

Payouts - M-Pesa

const payout = await intasend.payouts().mpesa({
  currency: 'KES',
  transactions: [
    { name: 'John Doe', account: '254712345678', amount: '500' },
  ],
});

// Approve payout
await intasend.payouts().approve(payout);

Wallets

// List wallets
const wallets = await intasend.wallets().list();

// Create wallet
const wallet = await intasend.wallets().create({
  label: 'Operations Wallet',
  wallet_type: 'WORKING',
  currency: 'KES',
});

// Get transactions
const transactions = await intasend.wallets().transactions('WALLET_ID');

// Intra-wallet transfer
await intasend.wallets().intraTransfer('SOURCE_ID', 'DEST_ID', 1000, 'Transfer');

Refunds

// Create refund
const refund = await intasend.refunds().create({
  invoice: 'INV-123',
  amount: 500,
  reason: 'CUSTOMER_REQUEST',
  reason_details: 'Customer cancelled order',
});

// List refunds
const refunds = await intasend.refunds().list();

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Type Definitions

All interfaces are exported for use in your TypeScript projects:

import IntaSend, {
  ChargePayload,
  MpesaStkPushPayload,
  PayoutPayload,
  PayoutTransaction,
  PayoutProvider,
  CreateWalletPayload,
  CreateRefundPayload,
  FundMpesaPayload,
  FundCheckoutPayload,
} from 'intasend-node';

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Breaking Changes

None. This is a backward-compatible rewrite. Both require() and import patterns work.