Scroll zkEVM Messenger L2->L1 Example

Send a message from L2 Scroll zkEVM 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
• getRelayFee.js
• sendL2ToL1Message.js
• getGreetingOnL1.js

Install

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

Set Signer

Create .env

PRIVATE_KEY=123...

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

Compile Contracts

npx hardhat compile

Deploy L2 Contract

Command

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

Output

L2Contract deployed to: 0x32EdD9E855F92C6Db51B86D5d004C6E7d11018a1

Deploy L1 Contract

Command

L2_CONTRACT=0x32EdD9E855F92C6Db51B86D5d004C6E7d11018a1 \
npx hardhat run --network goerli scripts/deployL1.js

Output

L1Contract deployed to: 0xc99668601516205D2305383c96134814b1f2CC11

Get Relay Fee

Command

npx hardhat run --network scroll scripts/getRelayFee.js

Output

l1BaseFee: 0.000000015391181204
gasLimit: 500000
fee: 0.007695590602

Send L2->L1 Message

Command (replace env vars with your values)

GREETING="hello world" \
L2_CONTRACT=0x32EdD9E855F92C6Db51B86D5d004C6E7d11018a1 \
L1_CONTRACT=0xc99668601516205D2305383c96134814b1f2CC11 \
npx hardhat run --network scroll scripts/sendL2ToL1Message.js

Output

sent tx hash 0x6ad8593e5aaf05496de0585f4e5dba9940c6268a1006df8160af6d5b1aa94210
https://blockscout.scroll.io/tx/0x6ad8593e5aaf05496de0585f4e5dba9940c6268a1006df8160af6d5b1aa94210

Get Greeting on L1

Command (Note: it can take a few minutes to hours after sending from L2 to see updated state on L1)

L1_CONTRACT=0xc99668601516205D2305383c96134814b1f2CC11 \
npx hardhat run --network goerli scripts/getGreetingOnL1.js

Output

greeting: hello world

Send L1->L2 Message

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

License

MIT @ Miguel Mota