Milestone 5: Reference Repos & Toolchain Compatibility

[Supercoolkayy]

As part of the Milestone 5 deliverables, the team has established reference implementations to demonstrate valid execution of ArbSys and ArbGasInfo across different toolchains. These examples serve as minimal, "one-command" verification suites to ensure that the precompiles function correctly in a live environment.

Below are the two reference repositories verifying these capabilities.

1. Community Reference: ArbiSmartVault

A special thanks to our community contributor @steven3002 for building a dedicated Smart Vault implementation. This project successfully exercises the precompiles in a realistic dapp scenario.

• Repository: steven3002/ArbiSmartVault
• Status: Validated ✅
• Description: A decentralized, automated linear vesting protocol built specifically for Arbitrum.
• Usage of Precompiles: It leverages ArbSys (0x...64) to fetch precise L2 block numbers for sub-minute vesting granularity and ArbGasInfo (0x...6C) to calculate real-time L1 gas reimbursement for relayers.
• Architecture: Implements a "Hub and Spoke" logic where a single Manager Contract creates individual vesting streams. It includes a Relayer Bot to monitor active vaults and execute claims when profitable.

2. Internal Reference: Hardhat Probes

To ensure robustness, we also maintain an internal suite of compatibility probes and example contracts.

• Location: Ox-rollup/probes/hardhat/contracts/examples
• Status: Validated ✅
• Description: This directory contains specific contract tests and minimal examples designed to stress-test the ArbSys and ArbGasInfo shims within a Hardhat environment.
• FeeAwareMint721: Demonstrates ERC-721 minting with fee-aware pricing that accounts for L1 calldata costs derived from ArbGasInfo.
• SettlementEscrow: Validates a settlement flow that escrows sufficient ether to cover L1 submission costs using getCurrentTxL1GasFees.
• RelayerGuard: A relayer protection mechanism that accepts or rejects sponsorship based on expected L1 data fees.
• ArbPrecompileProbe: A direct diagnostic contract to read Chain ID and Gas Estimates from the precompiles in both shim and native modes.

ℹ️ Note on Delivery Timeline

While these reference examples are a formalized deliverable for Milestone 5, the core work for the internal probes (Item 2) was proactively completed and merged during the Milestone 3 cycle. The team prioritized this early integration to ensure that our compatibility layer was stable enough to support complex testing scenarios well before this milestone deadline.

These examples confirm that developers can interact with the Arbitrum precompiles using standard Ethereum tooling without modification.