General Message Passing with Amplifier Example

This example shows the execution of a GMP call from the Ethereum Sepolia to the Avalanche Fuji testnets.

Prerequisites

You will need:

A funded wallet on devnet-amplifier
A Solidity contract deployed to the Ethereum Sepolia and Avalanche Fuji testnets
- We use a sample contract throughout this demo

Helpful references

Send a GMP call between two chains

Execute the contract call on the source chain

Use callContract() to execute the contract call on Ethereum Sepolia, then locate the ContractCall event in the transaction details on Axelarscan, which should look something like this. Note the transaction hash and log index.

Verify messages at the source chain gateway

Once the transaction is finalized on the source chain, call verify_messages at the source chain’s AxelarGateway:

axelard tx wasm execute axelar18zrymnzgdmutdjhqlfsslzy4yvzw8uylysjwqlq4uk4muq3qx30qde39qz \
  '{
      "verify_messages":
        [
          {
            "cc_id":
              {
                "source_chain":"eth-sepolia",
                "message_id":"0x7bf03d8fc010f28de8689a24f12a515b7968ea1dc139ed4e7520acfc22f4a0e4-1"
              },
            "destination_chain":"avalanche-fuji",
            "destination_address":"0x9F101c23CAcFC7773aAcaE0034d2b34B888dDC91",
            "source_address":"0x857d737C37A83d6294bA801DD6874dcD6BdbC707",
            "payload_hash":"d9f29a4e347ad89dc70490124ee6975fbc0693c7e72d6bc383673bfd0e8841f2"
          }
        ]
  }' \
  --from wallet \
  --keyring-backend test \
  --node http://devnet-amplifier.axelar.dev:26657 \
  --chain-id devnet-amplifier \
  --gas-prices 0.00005uamplifier \
  --gas auto --gas-adjustment 1.5

Note: message_id corresponds to the transaction hash of the transaction on the source chain.

Once this has been sent, you can wait for the transaction to be verified, this will usually takes 1-3 blocks. Then call route_messages:

axelard tx wasm execute axelar18zrymnzgdmutdjhqlfsslzy4yvzw8uylysjwqlq4uk4muq3qx30qde39qz \
  '{
    "route_messages":
      [
          {
            "cc_id":
              {
                "source_chain":"eth-sepolia",
                "message_id":"0x7bf03d8fc010f28de8689a24f12a515b7968ea1dc139ed4e7520acfc22f4a0e4-1"
              },
            "destination_chain":"avalanche-fuji",
            "destination_address":"0x9F101c23CAcFC7773aAcaE0034d2b34B888dDC91",
            "source_address":"0x857d737C37A83d6294bA801DD6874dcD6BdbC707",
            "payload_hash":"d9f29a4e347ad89dc70490124ee6975fbc0693c7e72d6bc383673bfd0e8841f2"
          }
      ]
  }' \
  --from wallet \
  --keyring-backend test \
  --node http://devnet-amplifier.axelar.dev:26657 \
  --chain-id devnet-amplifier \
  --gas-prices 0.00005uamplifier \
  --gas auto --gas-adjustment 1.5

Call construct_proof at the multisig-prover corresponding to the destination chain:

axelard tx wasm execute axelar1p22kz5jr7a9ruu8ypg40smual0uagl64dwvz5xt042vu8fa7l7dsl3wx8q \
  '{
    "construct_proof":
          [
            {
              "source_chain":"eth-sepolia",
              "message_id":"0x7bf03d8fc010f28de8689a24f12a515b7968ea1dc139ed4e7520acfc22f4a0e4-1"
            }
          ]
  }' \
  --from wallet \
  --keyring-backend test \
  --node http://devnet-amplifier.axelar.dev:26657 \
  --chain-id devnet-amplifier \
  --gas-prices 0.00005uamplifier \
  --gas auto --gas-adjustment 1.5

Note the multisig_session_id in the output:

{\"key\":\"multisig_session_id\",\"value\":\"881\"}

Retrieve the signed batch of messages

Wait for signing to complete, which usually takes 1-3 blocks. Then call get_proof:

axelard q wasm contract-state smart axelar1p22kz5jr7a9ruu8ypg40smual0uagl64dwvz5xt042vu8fa7l7dsl3wx8q \
  '{
    "proof":
      {
        "multisig_session_id":"881"
      }
  }' --node http://devnet-amplifier.axelar.dev:26657

The output should look something like this:

data:
  message_ids:
  - message_id: 0x7bf03d8fc010f28de8689a24f12a515b7968ea1dc139ed4e7520acfc22f4a0e4-1
    source_chain: eth-sepolia
  multisig_session_id: "881"
  payload:
    messages:
    - cc_id:
        message_id: 0x7bf03d8fc010f28de8689a24f12a515b7968ea1dc139ed4e7520acfc22f4a0e4-1
        source_chain: eth-sepolia
      destination_address: 0x9F101c23CAcFC7773aAcaE0034d2b34B888dDC91
      destination_chain: avalanche-fuji
      payload_hash: d9f29a4e347ad89dc70490124ee6975fbc0693c7e72d6bc383673bfd0e8841f2
      source_address: 0x857d737C37A83d6294bA801DD6874dcD6BdbC707
  status:
    completed:
      execute_data: 64f1d85a000000000000000000000000000000000000000000000000000000000000004000000000000000000000000000000000000000000000000000000000000002400000000000000000000000000000000000000000000000000000000000000001000000000000000000000000000000000000000000000000000000000000002000000000000000000000000000000000000000000000000000000000000000a000000000000000000000000000000000000000000000000000000000000000e000000000000000000000000000000000000000000000000000000000000001600000000000000000000000009f101c23cacfc7773aacae0034d2b34b888ddc91d9f29a4e347ad89dc70490124ee6975fbc0693c7e72d6bc383673bfd0e8841f2000000000000000000000000000000000000000000000000000000000000000b6574682d7365706f6c696100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000443078376266303364386663303130663238646538363839613234663132613531356237393638656131646331333965643465373532306163666332326634613065342d3100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000002a30783835376437333743333741383364363239346241383031444436383734646344364264624337303700000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000004000000000000000000000000000000000000000000000000000000000000001800000000000000000000000000000000000000000000000000000000000000060000000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000000000002b5c75000000000000000000000000000000000000000000000000000000000000000300000000000000000000000051380cbf0777990e197a3e498ffafd26143e35f8000000000000000000000000000000000000000000000000000000000000000100000000000000000000000061373485594010371dfbf3a8f8bd1736bfda7c090000000000000000000000000000000000000000000000000000000000000001000000000000000000000000c70aa87b38e6ab3c0df6e56338f96a5c00e6530800000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000002000000000000000000000000000000000000000000000000000000000000004000000000000000000000000000000000000000000000000000000000000000c0000000000000000000000000000000000000000000000000000000000000004152119e65c7c80829542bfb7766dfd6a7d628a59533a3040db6ee3f35ab7b8c8d38b8e023a3a1c821e2512cfdcfcee73dd54a0d2ad858900cefbc959f7d80610e1c0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000417d0c127646384b5ab7145dce5b9adabdf9faca911f119419bd68802e4b3850d85d0b34bd86b90c56daf6ef2ba2821573e87653c462da031793e9dc67e7ef455e1b00000000000000000000000000000000000000000000000000000000000000

Relay the execute data to the destination chain gateway

The execute data can be relayed to the destination chain’s AxelarGateway in a number of ways. Here’s how to do it with node.js using ethers:

await wallet.sendTransaction({to: gatewayAddress, data: "0x"+executeData, gasLimit:ethers.BigNumber.from(5e+06)}).then((tx) => tx.wait())

Execute the contract

Fill in the appropriate values and execute the contract. The command_id can be found in the response to the get_proof query:

await contract.execute(ethers.utils.arrayify(command_id),source_chain, source_address, ethers.utils.arrayify(payload)).then((tx) => tx.wait())