Polygon zkEVM Messenger L1->L2 Example

Send a message from L1 Goerli to L2 Polygon zkEVM testnet.

Example

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

The L1 contract has a method sendMessageToL2 that sends a message from L1 to L2 contract to set a greeting message on L2 contract. It sends the encoded calldata to execute setGreeting on L2 which can only be called if the message was sent by the L1 contract.

Files

• L2Contract.sol
• L1Contract.sol
• deployL2.js
• deployL1.js
• sendL1ToL2Message.js
• waitForInclusion.js
• finalizeMessageOnL2.js
• getGreetingOnL2.js

Install

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

Set Signer

Create .env

PRIVATE_KEY=123...

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

Compile Contracts

npx hardhat compile

Deploy L1 Contract

Command

npx hardhat run --network goerli scripts/deployL1.js

Output

L1Contract deployed to: 0xF20b8Fd13c48b68d1820cFd6d0D531a383b1AAaD

Deploy L2 Contract

Command

L1_CONTRACT=0xF20b8Fd13c48b68d1820cFd6d0D531a383b1AAaD \
npx hardhat run --network polygonzkevm scripts/deployL2.js

Output

L2Contract deployed to: 0x7aEF554acf5fBaCd2161027F24528f33fc7fCA95

Send L1->L2 Message

Command (replace env vars with your values)

GREETING="hello world" \
L1_CONTRACT=0xF20b8Fd13c48b68d1820cFd6d0D531a383b1AAaD \
L2_CONTRACT=0x7aEF554acf5fBaCd2161027F24528f33fc7fCA95 \
npx hardhat run --network goerli scripts/sendL1ToL2Message.js

Output

sent tx hash 0xdc954d46caa59e41710a70a4a5b0204fdb3f9f7aae983179a3ee6bfb82ad19bc
https://goerli.etherscan.io/tx/0xdc954d46caa59e41710a70a4a5b0204fdb3f9f7aae983179a3ee6bfb82ad19bc

Wait for L2 Root Inclusion

Command

L1_TX_HASH=0xdc954d46caa59e41710a70a4a5b0204fdb3f9f7aae983179a3ee6bfb82ad19bc \
L2_CONTRACT=0x7aEF554acf5fBaCd2161027F24528f33fc7fCA95 \
npx hardhat run --network polygonzkevm scripts/waitForInclusion.js

Output

Waiting for L2 root inclusion (this may take up to 20 minutes)...
{
  "leaf_type": 1,
  "orig_net": 0,
  "orig_addr": "0xF20b8Fd13c48b68d1820cFd6d0D531a383b1AAaD",
  "amount": "0",
  "dest_net": 1,
  "dest_addr": "0x7aEF554acf5fBaCd2161027F24528f33fc7fCA95",
  "block_num": "8811178",
  "deposit_cnt": "82717",
  "network_id": 0,
  "tx_hash": "0xdc954d46caa59e41710a70a4a5b0204fdb3f9f7aae983179a3ee6bfb82ad19bc",
  "claim_tx_hash": "",
  "metadata": "0xa41368620000000000000000000000000000000000000000000000000000000000000020000000000000000000000000000000000000000000000000000000000000000b68656c6c6f20776f726c64000000000000000000000000000000000000000000",
  "ready_for_claim": true
}
Ready to finalize message

Finalize Message On L2

Command

L1_TX_HASH=0xdc954d46caa59e41710a70a4a5b0204fdb3f9f7aae983179a3ee6bfb82ad19bc \
L1_CONTRACT=0xF20b8Fd13c48b68d1820cFd6d0D531a383b1AAaD \
L2_CONTRACT=0x7aEF554acf5fBaCd2161027F24528f33fc7fCA95 \
npx hardhat run --network polygonzkevm scripts/finalizeMessageOnL2.js

Output

verified: true
sent tx hash 0xc98c79f95131148057d79411d55521b145f5c5cbf63df909539dbe589605ab63
https://testnet-zkevm.polygonscan.com/tx/0xc98c79f95131148057d79411d55521b145f5c5cbf63df909539dbe589605ab63

Get Greeting on L2

Command

L2_CONTRACT=0x7aEF554acf5fBaCd2161027F24528f33fc7fCA95 \
npx hardhat run --network polygonzkevm scripts/getGreetingOnL2.js

Output

greeting: hello world

Send L2->L1 Message

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

License

MIT @ Miguel Mota