miguelmota / optimism-messenger-l2-to-l1-example

Send a message from L2 Optimism testnet to L1 Goerli.

Optimism Messenger L2->L1 Example

Send a message from L2 Optimism testnet to L1 Goerli.

Example

There's two contracts; L2Contract.sol and L1Contract.sol

The L2 contract has a method sendGreetingMessageToL1 that sends a message form L2 to L1 contract to set a greeting message on L1 contract. It sends the encoded calldata to execute setGreeting on L1 which can only be called if the message was sent by the L2 contract.

Files

• L2Contract.sol
• L1Contract.sol
• deployL2.js
• deployL1.js
• sendL2ToL1Message.js
• waitForInclusion.js
• finalizeMessageOnL1.js
• getGreetingOnL1.js

Install

git clone https://github.com/miguelmota/optimism-messenger-l2-to-l1-example.git
cd optimism-messenger-l2-to-l1-example
npm install

Set Signer

Create .env

PRIVATE_KEY=123...

Make sure private key has funds on both Optimism testnet and Goerli.

Compile Contracts

npx hardhat compile

Deploy L2 Contract

Command

npx hardhat run --network optimism scripts/deployL2.js

Output

L2Contract deployed to: 0x91CB0FEd918626866aC82120727ec1B649Ce7f11

Deploy L1 Contract

Command

L2_CONTRACT=0x91CB0FEd918626866aC82120727ec1B649Ce7f11 \
npx hardhat run --network goerli scripts/deployL1.js

Output

L1Contract deployed to: 0xAdB642a1122413d826cBE35a5F4c328Fc80c3Ff0

Send L2->L1 Message

Command (replace env vars with your values)

GREETING="hello world" \
L2_CONTRACT=0x91CB0FEd918626866aC82120727ec1B649Ce7f11 \
L1_CONTRACT=0xAdB642a1122413d826cBE35a5F4c328Fc80c3Ff0 \
npx hardhat run --network optimism scripts/sendL2ToL1Message.js

Output

sent tx hash 0x0536dbf443e596b5c7f23dc09a2d03b8d8dbdb73e20ff53254f5360e9ff561f3
https://goerli-optimism.etherscan.io/tx/0x0536dbf443e596b5c7f23dc09a2d03b8d8dbdb73e20ff53254f5360e9ff561f3

Wait for L1 Root Inclusion

Command

L2_TX_HASH=0x0536dbf443e596b5c7f23dc09a2d03b8d8dbdb73e20ff53254f5360e9ff561f3 \
npx hardhat run --network optimism scripts/waitForInclusion.js

Output

Waiting for L1 root inclusion (this may take up to 10 minutes)...
L1 message ready to prove

Finalize Message On L1

Command

L2_TX_HASH=0x0536dbf443e596b5c7f23dc09a2d03b8d8dbdb73e20ff53254f5360e9ff561f3 \
npx hardhat run --network goerli scripts/finalizeMessageOnL1.js

Output

prove message tx: 0x3c87b97838a1f7674104683d0fc3801ed837c8dff6142862538531b20e538ec6
https://goerli.etherscan.io/tx/0x3c87b97838a1f7674104683d0fc3801ed837c8dff6142862538531b20e538ec6
relay message tx: 0x69b3dd18fa9033f445ba8d411e6b5e61edd3230f25e3accecf3c10c672234f4f
https://goerli.etherscan.io/tx/0x69b3dd18fa9033f445ba8d411e6b5e61edd3230f25e3accecf3c10c672234f4f
message relayed on L1

Get Greeting on L1

Command

L1_CONTRACT=0xd7f8d5a683D51fF90Aff7C25430CA3abAe3F80A0 \
npx hardhat run --network goerli scripts/getGreetingOnL1.js

Output

greeting: hello world

Send L1->L2 Message

See https://github.com/miguelmota/optimism-messenger-l1-to-l2-example

License

MIT @ Miguel Mota