RuneERC20 – Bitcoin-Standard ERC-20 Example with Midl

This repository shows the minimal Solidity and Hardhat examples with common use cases. Such as:

ERC20 Assets emitted with native BTC as collateral

Required to mint, burn and redeem a Bitcoin-backed asset on an EVM chain without bridges or wrappers.
It implements the following flow:

1. A user sends real bitcoin to a custodian-controlled address and signs an on-chain MintIntent.
2. Midl validators watch the Bitcoin mempool, verify the deposit and call the EVM contract to mint the same amount of ERC-20 (RuneERC20).
3. The user can later burn the token to trigger redemption; the custodian releases the original sats.
4. A built-in circuit-breaker lets the custodian refuse redemptions from tainted addresses, exactly the mechanism BitGo used to stay safe during the 2021 BadgerDAO exploit.

Proxy Contracts deployment with multiple same artifact based deployments

Can be run with deploy_Proxies script

---

Contents

Path	Purpose
contracts/CollateralERC20.sol	Simple ERC-20 that can act as alternative collateral.
contracts/RuneERC20.sol	Main token contract – supports minting with BTC or with the collateral token.
deploy/000_deploy_CollateralERC20.ts	Hardhat‑deploy script for the collateral token.
deploy/001_deploy_RuneERC20.ts	Deploys RuneERC20 and wires it to the collateral token.
deploy/002_writeAdminMinting.ts	Shows a privileged “admin mint” used to seed initial supply.
deploy/003_write_CollateralERC20BasedMinting.ts	Approves collateral and mints RBTC using the ERC‑20 path.
deploy/004_write_CollateralBitcoinMinting.ts	Mints RBTC by sending real BTC as collateral.
deploy/005_write_RequestRedemption.ts	Burns RBTC and requests release of the underlying sats.
hardhat.config.ts	Network + Midl plugin configuration (defaults to Midl regtest).

---

Prerequisites

• Node >= 20 (the repo is locked with Volta to 22.17.0).
• Yarn or npm for package management.
• A regtest bitcoin balance (see next section).

---

Getting regtest bitcoin

Before you can deploy or test, you need a few testnet sats on Midl regtest.

1. Use the faucet: open https://faucet.etna.midl.xyz and paste a regtest BTC address.
2. Or contact the Midl team: ping @midl_xyz in the Telegram community and provide your address.

---

Quick-start

# 1. Clone and install
git clone https://github.com/midl-xyz/midl-solidity-on-bitcoin-example.git
cd midl-solidity-on-bitcoin-example
pnpm install            # or npm install / yarn install

# 2. Copy the env template and paste your mnemonic
cp .env.example .env
$EDITOR .env             # set MNEMONIC=...

# 3. Deploy to Midl regtest
pnpm hardhat deploy