EVM

Introduction

This document outlines the main functionalities of the Brotocol Bridge as deployed on EVM-compatible blockchains. The core aspects of the bridging operation are implemented in the BridgeEndpoint contract, which acts as the main entry and exit point for cross-chain operations, ensuring that assets are securely locked, minted/burned, transferred, and released. The BridgeEndpointWithSwap contract extends this functionality by incorporating swaps, allowing bridging and swapping to occur in within a single transaction.

The Brotocol ecosystem offers two main features in its EVM implementation:

• The bridging of ERC-20 assets: these contracts interact with Brotocol's off-chain protocol actors to allow the transfer of assets back and forth between EVM-compatible blockchains and Stacks.

• The swapping of tokens in the bridging process via external liquidity aggregators.

EVM Chain Bridge

This is a simplified representation on the EVM Chain Bridge's main goal.

*To see more information on the registry contract, see the auxiliary contracts section.

Bridge Endpoint

• Contract names: BridgeEndpoint, BridgeEndpointWithSwap.

• Complete technical documentation

This endpoint's main responsibility is serving as the entry and exit point for assets moving along Brotocol's cross-chain bridge. Sometimes, it also involves swapping to other tokens as part of the peg-in process.

Auxiliary Contracts

These contracts do not include the implementation of any core functionality but they serve as a support for other contracts to facilitate calculations and common storage management.

• Bridge Registry: this contract keeps a record of approved tokens, validators, relayers and fees. It also keeps a record of the generated orders and their statuses. Its latest version can be found at BridgeRegistry.sol.