Flare Bridge

Try it out!

https://flare-bridge.vercel.app/

Presentation

Contract Addresses

Coin on Sepolia: 0x5187763e09a672eda81F27e622129Ac28393ca53

Coin on Coston: 0x8c49e01E86d9ef98eA963Be48B1E41297E06F817

Relay on Coston: 0x9b4e6a477EC865551ca4f5558420C908482F6073

Relay on Sepolia: 0x2cD3CbcC13e5b165b6b43708788B4477778bC171

Gatway on Coston: 0x8b1274d063593F0973afF1710EA4490BE67AE9f2

Gateway on Sepolia: 0x0c2eFE1D385151870B3fFb9901B7a0FB1C5a1314

Technical Implementation

• Relayer
  • Rewritten in Node.js
  • Previous relayer was busy waiting / querying every individual block
  • New relayer simply adds listeners on the relevant contract events
  • Generates proofs on both Sepolia and Coston for events
  • Submits proofs along with the relevant calldata to the other network
• Gateway Contract
  • Supports thorough access controll
    • Owners set who are the allowed relayers
  • Allows the user to send tokens
    • Burns the tokens
    • Calls the relay contract
  • Verifies proofs before minting tokens
    • Verifies the Merkle root of the proof using Flare's contracts
    • Verifies that there is a burn event
    • Verifies that the user that submitted the request is the same as the user who burned
    • Verifies the user is redeeming tokens in the same contract pair as they burned
    • Verifies the user is redeeming exactly as many tokens as they burned
    • Verifies the user has not previously tried to attest this burn event
    • Verifies that a valid relayer is calling with the burn
• Relay Contract
  • Generic on-chain message sending contract
  • Application agnostic
  • Supports arbitrary calldata message calls
  • Not responsible for verifying proofs

Examples of Working Tx

Sepolia to Coston: https://sepolia.etherscan.io/tx/0x5cce8a8a2bb96565b84c69868862666d031790a74d16d8ff912dfe2dd27e4ca6 https://coston-explorer.flare.network/tx/0xe90b75906822ea047351bad6a455ba731522cec8dd211810c6dc19554ed5f75e

Coston to Sepolia:

https://coston-explorer.flare.network/tx/0xf0b6ac54f080496fbf0e0ad70cc36998fa9a46abc00abd5144aa8d043d20f15f

https://sepolia.etherscan.io/tx/0x543ea3543b99f824dad6d64c143ca52644ad1304df159587830afb86a940dff0

Deployment

cd gateway-contracts

npx hardhat run scripts/deployCoin.js --network sepolia

npx hardhat run scripts/deployCoin.js --network coston


etc...

AWS

pm2 report

pm2 start "node src/server.js sepolia" -n sepolia

pm2 start "node src/server.js coston" -n coston

pm2 start