Contracts Overview

Contract Architecture

Melt’s smart contracts implement a Lock & Mint bridge pattern using LayerZero V2 for cross-chain messaging.

Source Chain                    HyperEVM
┌──────────────┐               ┌──────────────────────┐
│  MeltBridge  │──LayerZero──▶│      MeltHub         │
│  (Lock)      │◀─────────────│  (Mint/Burn)         │
└──────────────┘               │                      │
                               │  ┌─── MeltFactory    │
                               │  │    (Deploy)       │
                               │  │                   │
                               │  └─── MeltAsset[]    │
                               │       (ERC20+OFT)    │
                               └──────────┬───────────┘
                                          │
                                    HyperCore
                                  (Precompiles)
                               ┌──────────────────┐
                               │  Spot Trading    │
                               │  Asset Bridges   │
                               └──────────────────┘

Contracts

Contract	Chain	Purpose
MeltHub	HyperEVM	Central hub — receives bridges, mints tokens, routes to HyperCore
MeltBridge	Source chains	Locks tokens, sends cross-chain messages to MeltHub
MeltAsset	HyperEVM	ERC20 + OFT wrapped token with role-based access
MeltFactory	HyperEVM	Deploys new MeltAsset tokens, manages HyperCore integration
MeltFeeController	HyperEVM	Per-user fee overrides for market makers and special integrations
MeltDebridgeHook	HyperEVM	Auto-deposits USDC from deBridge into HyperCore spot balance

Tech Stack

Solidity 0.8.22
Foundry (Forge + Cast) for testing and deployment
LayerZero V2 OApp for cross-chain messaging
OpenZeppelin Contracts for ERC20, AccessControl, Pausable, ReentrancyGuard

Key Concepts

Config Key

Tokens are identified by a configKey — the keccak256 hash of (originalToken, sourceEid). This allows the same underlying token to have different configs when bridged from different source chains.

Roles

Role	Granted To	Purpose
`MINTER_ROLE`	MeltHub, MeltFactory	Mint wrapped tokens
`BURNER_ROLE`	MeltHub	Burn wrapped tokens without approval
`ADMIN_ROLE`	Multisig	Admin operations (set fees, pause tokens)
`REGISTRAR_ROLE`	MeltFactory	Register tokens and configure HyperCore
`DEFAULT_ADMIN_ROLE`	MeltFactory (then transferable)	Manage roles on MeltAsset
`owner`	Multisig	Owner operations on MeltBridge, MeltFactory

Next Steps

Integration Guide — flows, code examples, events, and fee structure
Deployment Addresses — all mainnet and testnet contract addresses

Smart Contracts

Integrations

Contract Architecture

Contracts

Tech Stack

Key Concepts

Config Key

Roles

Next Steps

​Contract Architecture

​Contracts

​Tech Stack

​Key Concepts

​Config Key

​Roles

​Next Steps

Contract Architecture

Contracts

Tech Stack

Key Concepts

Config Key

Roles

Next Steps