HOT <> Bridged HOT Bridge

A two-way bridge between HOT tokens on Ethereum and bridged HOT on Holochain.

Overview

This repository contains the Ethereum-side infrastructure for the HOT <> bridged HOT swap:

• LOCK: Users send HOT on Ethereum and receive bridged HOT on Holochain
• CLAIM: Users burn bridged HOT on Holochain and receive HOT on Ethereum via signed coupons

┌─────────────────────────────────────────────────────────────────┐
│                    SHARED LIQUIDITY POOL                         │
│         (Raindex Orderbook Vault owned by HoloLockVault)        │
│                                                                  │
│   LOCK (HOT→bHOT)            HOT Tokens             CLAIM (bHOT→HOT)
│   ─────────────────►    ┌───────────────┐    ◄─────────────────
│   Deposits INTO         │               │         Withdraws FROM
│                         └───────────────┘                        │
└─────────────────────────────────────────────────────────────────┘

Components

Component	Description	Language
src/HoloLockVault.sol	Smart contract for locking HOT and managing claim orders	Solidity
src/holo-claim.rain	Rainlang expression for validating claim coupons	Rainlang
bridge-orchestrator/	Service that watches Lock events, drives the Holochain bridge, and generates withdrawal coupons	Rust
ui/	Web interface for locking and claiming	SvelteKit

Quick Start

Prerequisites

• Foundry (forge, cast)
• Rust (for bridge-orchestrator)
• Node.js 20+ (for UI)
• MetaMask with Sepolia ETH

1. Deploy to Sepolia

# Set up environment
cp .env.example .env
# Edit .env with your private key

# Deploy all contracts
./deploy-sepolia.sh token       # Deploy MockHOT token
./deploy-sepolia.sh vault       # Deploy HoloLockVault
./deploy-sepolia.sh mint        # Mint test tokens
./deploy-sepolia.sh fund        # Fund the vault
./deploy-sepolia.sh order-via-vault  # Deploy claim order

2. Run the UI

cd ui
npm install
npm run dev
# Open http://localhost:5173

3. Run the bridge orchestrator

cd bridge-orchestrator
cp .env.example .env
# Edit with your Sepolia + Holochain settings
cargo run

The orchestrator watches Lock events on Ethereum, drives the Holochain bridge, and generates signed withdrawal coupons for claim flows.

Sepolia Deployment

Contract	Address
MockHOT Token	0xeaC8eEEE9f84F3E3F592e9D8604100eA1b788749
HoloLockVault	0xE3E064e3C2EEf66cb93dA8D8114F5084E92F48D6
Orderbook (Raindex)	0xfca89cD12Ba1346b1ac570ed988AB43b812733fe
Claim Order Hash	0x5eeff397dac16f82057e20da98cf183daf95a0695980a196270e9e0922a275f9

Documentation

• DEPLOY.md - Detailed deployment guide
• LOCK_INFRASTRUCTURE_PLAN.md - Architecture and design documentation

How It Works

Lock Flow (HOT -> Bridged HOT)

1. User approves HoloLockVault to spend their HOT
2. User calls lock(amount, holochainAgentPubKey)
3. HoloLockVault deposits tokens to its Raindex vault
4. Lock event emitted with amount and Holochain agent
5. Bridge orchestrator detects the event
6. Holochain side credits bridged HOT to agent

Claim Flow (Bridged HOT -> HOT)

1. User burns bridged HOT on Holochain
2. Holo backend generates signed coupon via Fireblocks
3. User receives coupon (URL or direct)
4. User visits claim page and submits coupon
5. Rainlang expression validates coupon (signer, expiry, nonce)
6. HOT transferred from vault to user's wallet

Development

# Build contracts
forge build

# Run tests
forge test

# Build the bridge orchestrator
cd bridge-orchestrator && cargo build

Security

• Test signer key in repo is for testing only
• Production uses Fireblocks MPC for signing
• Each coupon has a unique nonce (prevents replay)
• Coupons have expiry timestamps
• Admin functions protected by access control