Polygon zkEVM Messenger L2->L1 Example

Send a message from L2 Polygon 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
• sendL2ToL1Message.js
• waitForInclusion.js
• finalizeMessageOnL1.js
• getGreetingOnL1.js

Install

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

Set Signer

Create .env

PRIVATE_KEY=123...

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

Compile Contracts

npx hardhat compile

Deploy L2 Contract

Command

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

Output

L2Contract deployed to: 0x8Da765bB3F8fbcae3647Fc326D1F7d3337a5882A

Deploy L1 Contract

Command

L2_CONTRACT=0x8Da765bB3F8fbcae3647Fc326D1F7d3337a5882A \
npx hardhat run --network goerli scripts/deployL1.js

Output

L1Contract deployed to: 0xd7f8d5a683D51fF90Aff7C25430CA3abAe3F80A0

Send L2->L1 Message

Command (replace env vars with your values)

GREETING="hello world" \
L2_CONTRACT=0x8Da765bB3F8fbcae3647Fc326D1F7d3337a5882A \
L1_CONTRACT=0xd7f8d5a683D51fF90Aff7C25430CA3abAe3F80A0 \
npx hardhat run --network polygonzkevm scripts/sendL2ToL1Message.js

Output

sent tx hash 0x0085f32974b2b847bacb829f9006d89248cc6e53e3fb86f45cc348d94542ca22
https://testnet-zkevm.polygonscan.com/tx/0x0085f32974b2b847bacb829f9006d89248cc6e53e3fb86f45cc348d94542ca22

Wait for L1 Root Inclusion

Command

L2_TX_HASH=0x0085f32974b2b847bacb829f9006d89248cc6e53e3fb86f45cc348d94542ca22 \
L1_CONTRACT=0xd7f8d5a683D51fF90Aff7C25430CA3abAe3F80A0 \
npx hardhat run --network polygonzkevm scripts/waitForInclusion.js

Output

Waiting for L1 root inclusion (this may take up to 60 minutes)...
{
  "leaf_type": 1,
  "orig_net": 1,
  "orig_addr": "0x8Da765bB3F8fbcae3647Fc326D1F7d3337a5882A",
  "amount": "0",
  "dest_net": 0,
  "dest_addr": "0xd7f8d5a683D51fF90Aff7C25430CA3abAe3F80A0",
  "block_num": "569430",
  "deposit_cnt": "23516",
  "network_id": 1,
  "tx_hash": "0x0085f32974b2b847bacb829f9006d89248cc6e53e3fb86f45cc348d94542ca22",
  "claim_tx_hash": "",
  "metadata": "0xa41368620000000000000000000000000000000000000000000000000000000000000020000000000000000000000000000000000000000000000000000000000000000b68656c6c6f20776f726c64000000000000000000000000000000000000000000",
  "ready_for_claim": true
}
Ready to finalize message

Finalize Message On L1

Command

L2_TX_HASH=0x0085f32974b2b847bacb829f9006d89248cc6e53e3fb86f45cc348d94542ca22 \
L1_CONTRACT=0xd7f8d5a683D51fF90Aff7C25430CA3abAe3F80A0 \
L2_CONTRACT=0x8Da765bB3F8fbcae3647Fc326D1F7d3337a5882A \
npx hardhat run --network goerli scripts/finalizeMessageOnL1.js

Output

sent tx hash 0xcaae7ee9dd1f8657a21f4598a4c8a9e97cd1341ddf1ca988ad371641bc3993af
https://goerli.etherscan.io/tx/0xcaae7ee9dd1f8657a21f4598a4c8a9e97cd1341ddf1ca988ad371641bc3993af

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/polygon-zkevm-messenger-l1-to-l2-example

License

MIT @ Miguel Mota