Chainbridge by ChainSafe - Connecting Ethereum and Moonbeam

Disclaimer: Projects themselves entirely manage the content in this guide. Moonbeam is a permissionless network. Any project can deploy its contracts to Moonbeam.

Introduction

ChainBridge is a modular, multi-directional bridge to interact with multiple networks, either EVM or Substrated-based chains. ChainBridge's implementation in Moonbeam is focused on connecting it to Ethereum using both EVM implementations.

At a high-level, ChainBridge is a message-passing protocol. A set of relayers are constantly looking for events, in either side of the bridge, which trigger a set of actions. Once a triggering event is noted, a set of relayers vote to execute the instructions (included in the event) in the chain on the other side of the bridge.

For example, the bridge can be used to transfer ERC-20 or ERC-721 natively. A set of handler contracts are pre-configured to handle both token standards. At its core, the token transfer mechanism works with a lock-mint, burn-unlock mechanism. First tokens are locked in the source chain, and an event is emitted, which is listened to by the relayers. Then, they vote and (if approved) execute the mint function, giving the same amount of tokens locked in the target chain to the corresponding address.

You can read more about ChainBridge (and ChainSafe) in the following links:

• ChainSafe Website
• ChainSafe Github
• ChainBridge documentation
• ChainBridge GitHub

You can contact the team via the following communication channels:

• Discord
• Twitter
• LinkedIn

Moonbase Alpha Implementation

ChainBridge is currently connecting the Moonbase Alpha TestNet with both Kovan and Rinkeby Ethereum's TestNets. You can find a detailed tutorial on how to use the bridge in this site.

Moonbase Alpha - Rinkeby

You can find all the contract's addresses that are relevant for the Moonbase Alpha - Kovan/Rinkeby bridge in the following table:

Contract	Address
Bridge	0x747e8C91C8661704b1c33b0365A89f7e988E1de3
ERC20 Handler	0xDC826cF5AD261FcD1D1dC404648B4D596Df88C8C
ERC721 Handler	0xa6DCb79BC155f732C0761eFCEd656927FFA97E9E
ERC20S Token	0x019F59AFbB89f0d395F905F7Ca0A48485619bcA5
ERC721M Token (mintable on Moonbase Alpha)	0xAC86f2e7C7C2e360eD0541fFDbb68710596E11B5

All of the above addresses are valid on both Kovan and Rinkeby. You will be able to specify which network to transfer the tokens to when interacting with the Bridge contract.

Moonbase Alpha ChainBridge UI

If you want to play around with transferring ERC20S tokens from Moonbase Alpha to Kovan or Rinkeby without having to set up the contracts in Remix, you can checkout the Moonbase Alpha ChainBridge UI.