@sky-mavis/flow-cash-sdk

A TypeScript SDK for deposit today, cash out tomorrow.

Installation

yarn add @sky-mavis/flow-cash-sdk
# or
npm install @sky-mavis/flow-cash-sdk

Usage Flow

The deposit flow consists of 3 simple steps:

Step 1: Get Form Data (Defaults, Currencies, Payment Methods)

import { DepositService } from '@sky-mavis/flow-cash-sdk';

const depositService = new DepositService();

// Get recommended defaults
const defaults = await depositService.getDefaults();
const { amount, source, paymentMethod } = defaults.recommended;

// Get available currencies
const currencies = await depositService.getCurrencies();

// Get available payment methods
const paymentMethods = await depositService.getPaymentTypes({
  source: 'vnd',
  destination: 'usdc_base',
  type: 'buy',
});

Step 2: Get Quotes (Onramper + Relay)

// Get quotes from Onramper
const quotes = await depositService.getQuotes({
  crypto: 'usdc_base',
  fiat: 'vnd',
  amount: '1000000',
  user: '0x742d35Cc6634C0532925a3b844Bc9e7595f0bEb',
  paymentMethod: 'momo',
  useDepositAddress: true, // Enable relay for cross-chain deposit
  fromToken: {
    chainId: 8453, // Base
    address: '0x833589fcd6edb6e08f4c7c32d4f71b54bda02913', // USDC on Base
    decimals: 6,
  },
  toToken: {
    chainId: 2020, // Ronin
    address: '0x0b7007c13325c48911f73a2dad5fa5dcbf808adc', // USDC on Ronin
    decimals: 6,
  },
});

// Select a quote
const selectedQuote = quotes[0];

// Get relay quote for deposit address
const relayQuote = await selectedQuote.getRelayQuote();
const depositAddress = relayQuote.steps[0].depositAddress;

Step 3: Initiate Checkout

// Initiate checkout
const checkout = await depositService.initiateCheckout({
  ramp: selectedQuote.ramp,
  source: 'vnd',
  destination: 'usdc_base',
  amount: 1000000,
  type: 'buy',
  paymentMethod: 'momo',
  network: 'base',
  quoteId: selectedQuote.quoteId,
  addresses: {
    '0x833589fcd6edb6e08f4c7c32d4f71b54bda02913': depositAddress,
  },
});

// Open checkout URL
window.open(checkout.message.transactionInformation.url, '_blank');

Project Structure

src/
├── index.ts              # Main entry point - public API
├── client/               # SDK client class
│   └── index.ts
├── types/                # TypeScript types
│   ├── index.ts
│   ├── common.ts         # Shared types (Address, TxHash)
│   ├── relay.ts          # Relay-specific types
│   └── onramper.ts       # Onramper-specific types
├── constants/            # Configuration constants
│   └── index.ts
├── providers/            # External API integrations
│   ├── relay.ts          # Relay.link provider
│   └── onramper.ts       # Onramper provider
└── utils/                # Helper functions
    ├── validation.ts     # Address/amount validation
    └── format.ts         # Amount formatting

Development

# Install dependencies
yarn install

# Build
yarn build

# Development mode with watch
yarn dev

# Lint
yarn lint

# Type check
yarn typecheck

Architecture

• client/ - Main SDK class that users interact with
• types/ - All TypeScript type definitions
• constants/ - API URLs, default values, chain configs
• providers/ - Wrapper classes for external APIs (Relay, Onramper)
• utils/ - Pure utility functions (validation, formatting)

License

MIT