zkSync Messenger L2->L1 Example

Send a message from L2 zkSync testnet to L1 Goerli and execute message on L1 Goerli after proving inclusion.

Example

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

The L2 contract has a method sendGreetingMessageToL1 that sends a message to L1 contract to set a greeting message on L1 contract.

The L1 contract has a method consumeMessageFromL2 that checks that the message was included in L2 block using zksync proveL2MessageInclusion and executes setGreeting call on itself 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
• executeMessageOnL1.js
• getGreetingOnL1.js

Install

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

Set Signer

Create .env

PRIVATE_KEY=123...

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

Compile Contracts

npx hardhat compile

Deploy L2 Contract

Command

npx hardhat deploy-zksync --network zksync

Output

deployed to 0xf32971F66593AbBd4D032015FAa0222871895b68

Deploy L1 Contract

Command

L2_CONTRACT=0xf32971F66593AbBd4D032015FAa0222871895b68 \
npx hardhat run --network goerli scripts/deployL1.js

Output

deployed to 0x9F2FFbF506cb803c184Ba0Cd3586e0bDFf23b772

Send L2->L1 Message

Command (replace env vars with your values)

```sh
GREETING="hello world" \
L2_CONTRACT=0xf32971F66593AbBd4D032015FAa0222871895b68 \
npx hardhat run --network zksync scripts/sendL2ToL1Message.js

Output

sent tx hash 0x56b1779fb907fb1349594d417106ebc05c4f9b226703d11f4b9bb6a5f0208995
https://goerli.explorer.zksync.io/tx/0x56b1779fb907fb1349594d417106ebc05c4f9b226703d11f4b9bb6a5f0208995

Wait for L1 Block Inclusion

Command

GREETING="hello world" \
L2_CONTRACT=0xf32971F66593AbBd4D032015FAa0222871895b68 \
L2_TX_HASH=0x56b1779fb907fb1349594d417106ebc05c4f9b226703d11f4b9bb6a5f0208995 \
npx hardhat run --network zksync scripts/waitForInclusion.js

Output

Waiting for L1 block inclusion (this may take up to 1 hour)...
L2 block: 5905135
L1 Index for Tx in block: 158
L1 Batch for block:  625353
Inclusion proof: [
  '0x9fc4abd6bd666a7a823c8565e53fd3b8c6f2e43d1859dd149c9c9600d77ea6c0',
  '0x612469e30d8f8915e68010312c953e8a0b3a942a7e3aaee989abfe70b9b0ec32',
  '0xfa24ab9fb3ad04ddcba2053773fafb91795e00dd4d2a18289ede57c0de35fda9',
  '0xd680791eca0636c988524e180ffa9732d8fcacd3d78960be289af616cd0e65f3',
  '0x9425a8eb5db9d4594b7f77f65c5c2b33782c3a475e76b45af589b929694a5064',
  '0x6c84e6cd4a6b04f6f2bf1d67e4bc5cbb3b1ce2bf3a951ff515e6c3115eb1811e',
  '0x66d7c5983afe44cf15ea8cf565b34c6c31ff0cb4dd744524f7842b942d08770d',
  '0xb04e5ee349086985f74b73971ce9dfe76bbed95c84906c5dffd96504e1e5396c',
  '0xac506ecb5465659b3a927143f6d724f91d8d9c4bdb2463aee111d9aa869874db'
]
proveL2MessageInclusion: true

Execute Message on L1

Command

GREETING="hello world" \
L1_CONTRACT=0x9F2FFbF506cb803c184Ba0Cd3586e0bDFf23b772 \
L2_CONTRACT=0xf32971F66593AbBd4D032015FAa0222871895b68 \
L2_TX_HASH=0x56b1779fb907fb1349594d417106ebc05c4f9b226703d11f4b9bb6a5f0208995 \
npx hardhat run --network goerli scripts/executeMessageOnL1.js

Output

sent tx hash 0x3b2dbbf2b65414cee1338bd1e2bce82588bf4aa86f057fc6e7651935ed43fde4
https://goerli.etherscan.io/tx/0x3b2dbbf2b65414cee1338bd1e2bce82588bf4aa86f057fc6e7651935ed43fde4

Get Greeting on L1

Command

L1_CONTRACT=0x9F2FFbF506cb803c184Ba0Cd3586e0bDFf23b772 \
npx hardhat run --network goerli scripts/getGreetingOnL1.js

Output

greeting: hello world

License

MIT @ Miguel Mota