USDG Gateway & Avalanche ICTT

USDG (USD Ghost) is the native stablecoin on Umbraline Testnet, backed 1:1 by USDC via Avalanche's Inter-Chain Token Transfer (ICTT) protocol.

Architecture

┌─────────────────────────────────────────────────────────────────┐
│                    Avalanche Fuji C-Chain                       │
│                                                                 │
│  ┌─────────┐      ┌──────────────────┐                         │
│  │  USDC   │ ──►  │  ERC20TokenHome  │  (Locks USDC)           │
│  └─────────┘      └────────┬─────────┘                         │
│                            │ Avalanche Warp Messaging          │
└────────────────────────────┼────────────────────────────────────┘
                             │
                             ▼
┌────────────────────────────┼────────────────────────────────────┐
│                    Umbraline Testnet (47474)                    │
│                            │                                    │
│                   ┌────────▼─────────┐                         │
│                   │  GhostTokenRemote │  (Mints USDG)          │
│                   │      (USDG)       │                         │
│                   └────────┬─────────┘                         │
│                            │                                    │
│                   ┌────────▼─────────┐                         │
│                   │    GhostVault    │  (vanish/summon)        │
│                   └──────────────────┘                         │
└─────────────────────────────────────────────────────────────────┘

Contract Addresses

Avalanche Fuji C-Chain (43113)

Contract	Address	Purpose
Test USDC	0x5425890298aed601595a70AB815c96711a31Bc65	Aave faucet USDC
ERC20TokenHome	0x255E85e3a021Cd8074D11dCD73FE342273178048	Locks USDC for bridging
TeleporterRegistry	0xF86Cb19Ad8405AEFa7d09C778215D2Cb6eBfB228	Teleporter coordination
Blockchain ID	0x7fc93d85c6d62c5b2ac0b519c87010ea5294012d1e407030d6acd0021cac10d5	ICTT routing

Umbraline Testnet (47474)

Contract	Address	Purpose
USDG (GhostTokenRemote)	0x2A3ad14479ecB02B2B59Fc6D239F0777a0afFE05	Stablecoin on L1
TeleporterRegistry	0xD984Bc60965390D70D3Bf744cfFD58D7E52D718E	Teleporter coordination
TeleporterMessenger	0x253b2784c75e510dD0fF1da844684a1aC0aa5fcf	Cross-chain messaging
Blockchain ID	0x4a449a82fed39ca256e89872ee71a24dc2291b848e1fb0785c25e33a0972d304	ICTT routing

Bridge Flow: USDC → USDG

const UMBRALINE_BLOCKCHAIN_ID = '0x4a449a82fed39ca256e89872ee71a24dc2291b848e1fb0785c25e33a0972d304';
const USDG_ADDRESS = '0x2A3ad14479ecB02B2B59Fc6D239F0777a0afFE05';
const ERC20_TOKEN_HOME = '0x255E85e3a021Cd8074D11dCD73FE342273178048';

// Step 1: Approve USDC on Fuji C-Chain
await usdc.approve(ERC20_TOKEN_HOME, amount);

// Step 2: Send via ICTT
await tokenHome.send({
  destinationBlockchainID: UMBRALINE_BLOCKCHAIN_ID,
  destinationTokenTransferrerAddress: USDG_ADDRESS,
  recipient: userAddress,
  primaryFeeTokenAddress: ethers.ZeroAddress,  // Pay fee in AVAX
  primaryFee: 0,
  secondaryFee: 0,
  requiredGasLimit: 250000n,
  multiHopFallback: ethers.ZeroAddress,
}, { value: 0 });  // No additional value needed

// Step 3: User receives USDG on Umbraline Testnet
// USDG can be vanished directly to GhostVault

USDG Features

• Privacy Ready: USDG can be vanished directly to GhostVault (no wrapper needed)
• Standard ERC-20: Fully compatible with DeFi protocols
• Bridgeable Back: Can be sent back to C-Chain via send() method on USDG contract

Getting Test USDC

Test USDC can be obtained from the Aave faucet:

• URL: https://app.aave.com/faucet/
• Network: Avalanche Fuji
• Token: USDC
• Address: 0x5425890298aed601595a70AB815c96711a31Bc65