@dappsoverapps.com/hardhat-patch

A Hardhat plugin that adds native support for Arbitrum precompiles to local development networks.

Features

• ArbSys Precompile (0x64): System-level utilities for L1↔L2 interactions
• ArbGasInfo Precompile (0x6C): Gas pricing and L1 cost estimation
• Modular Registry: Easy to add new precompile handlers
• Configurable: Customize chain ID, ArbOS version, and gas pricing

Installation

npm install @dappsoverapps.com/hardhat-patch

Usage

Basic Setup

// hardhat.config.ts
import { HardhatUserConfig } from "hardhat/config";

const config: HardhatUserConfig = {
  solidity: "0.8.19",
  networks: {
    hardhat: {
      // Enable Arbitrum features
      arbitrum: {
        enabled: true,
        chainId: 42161, // Arbitrum One
        arbOSVersion: 20,
      },
    },
  },
};

export default config;

Custom Configuration

const config: HardhatUserConfig = {
  solidity: "0.8.19",
  networks: {
    hardhat: {
      arbitrum: {
        enabled: true,
        chainId: 421613, // Arbitrum Goerli
        arbOSVersion: 21,
        l1BaseFee: BigInt(15e9), // 15 gwei
        gasPriceComponents: {
          l2BaseFee: BigInt(2e9), // 2 gwei
          l1CalldataCost: BigInt(20), // 20 gas per byte
          l1StorageCost: BigInt(0),
          congestionFee: BigInt(1e8), // 0.1 gwei
        },
      },
    },
  },
};

Programmatic Usage

import { HardhatArbitrumPatch } from "@dappsoverapps.com/hardhat-patch";

// Create plugin instance
const arbitrumPatch = new HardhatArbitrumPatch({
  chainId: 42161,
  arbOSVersion: 20,
});

// Access the registry
const registry = arbitrumPatch.getRegistry();

// Check if a precompile is supported
if (arbitrumPatch.hasHandler("0x0000000000000000000000000000000000000064")) {
  console.log("ArbSys precompile is available");
}

// List all handlers
const handlers = arbitrumPatch.listHandlers();
console.log(
  "Available precompiles:",
  handlers.map((h) => h.name)
);

Supported Precompiles

ArbSys (0x64)

• arbChainID() - Returns the Arbitrum chain ID
• arbBlockNumber() - Returns the current L2 block number
• arbBlockHash(uint256) - Returns block hash for given block number
• arbOSVersion() - Returns the current ArbOS version

ArbGasInfo (0x6C)

• getPricesInWei() - Returns 5-tuple of gas price components
• getL1BaseFeeEstimate() - Returns estimated L1 base fee
• getCurrentTxL1GasFees() - Returns L1 gas fees for current transaction
• getPricesInArbGas() - Returns 3-tuple in ArbGas units

Development

Building

npm run build

Testing

npm test

Linting

npm run lint

Architecture

The plugin uses a modular registry system:

1. Registry Interface: Defines the contract for precompile handlers
2. Handler Implementation: Each precompile has its own handler class
3. Plugin Integration: Automatically registers handlers on Hardhat startup
4. Configuration: Supports customization of key parameters

Contributing

1. Fork the repository
2. Create a feature branch
3. Make your changes
4. Add tests
5. Submit a pull request

License

MIT