Signing EIP-1559 Transaction

In the previous section, we explored the principles and concepts behind the Near Multi-Chain DAO Governance Contract. Now, it's time to put that knowledge into action by actually generating a signature.

Step 1: Crafting the EIP-1559 Transaction Payload

The register_signature_request function on the Multi-Chain DAO Governance Contract is used to record the intent to generate a signature for a specific transaction payload. This function allows you to define who can sign the transaction and what the transaction contains.

Here’s the sample payload you will submit to the contract:

{
  "request": {
    "allowed_account_id": "executor.testnet",
    "derivation_seed_number": 0,
    "transaction_payload": {
      "to": "0xe2a01146FFfC8432497ae49A7a6cBa5B9Abd71A3",
      "nonce": "0",
      "function_data": {
        "function_abi": {
          "inputs": [
            {
              "internalType": "uint256",
              "name": "_num",
              "type": "uint256"
            }
          ],
          "name": "set",
          "outputs": [],
          "stateMutability": "nonpayable",
          "type": "function"
        },
        "arguments": [
          {
            "Uint": "A97"
          }
        ]
      }
    }
  }
}

Arguments

• allowed_account_id: This is the account allowed to sign the transaction later. It grants permission to this account to generate the required signatures for the transaction.

• derivation_seed_number: This number is used to craft the derivation path along with predecessor account id. Learn more about derivation paths here.

• transaction_payload: This is the actual payload of the transaction that will become EIP-1559 compatible later. In this case, it contains the following:

  • to: The recipient address of the transaction.
  • nonce: The transaction nonce, used to ensure uniqueness.
  • function_data: (optional) Defines the function that will be called on the recipient's contract. It includes:
    • function_abi: The ABI of the function being called.
    • arguments: The input arguments for the function, encoded appropriately.

note

Integer arguments must be base64 encoded

Step 2: Creating a Request on the Multisig Contract

To call register_signature_request on the Multi-Chain DAO Governance Contract, you need to submit a request through your Multisig contract. This ensures that the decision to generate a signature is confirmed by the necessary members.

near contract call-function as-transaction multisignature.testnet add_request json-args '{
    "request": {
        "receiver_id": "abstract-dao.testnet",
        "actions": [
            {
                "type": "FunctionCall",
                "method_name": "register_signature_request",
                "args": {
                    "request": {
                        "allowed_account_id": "executor.testnet",
                        "derivation_seed_number": 0,
                        "transaction_payload": {
                            "to": "0xe2a01146FFfC8432497ae49A7a6cBa5B9Abd71A3",
                            "nonce": "0",
                            "function_data": {
                                "function_abi": {
                                    "inputs": [
                                        {
                                            "internalType": "uint256",
                                            "name": "_num",
                                            "type": "uint256"
                                        }
                                    ],
                                    "name": "set",
                                    "outputs": [],
                                    "stateMutability": "nonpayable",
                                    "type": "function"
                                },
                                "arguments": [
                                    {
                                        "Uint": "A97"
                                    }
                                ]
                            }
                        }
                    }
                },
                "gas": "100000000000000",
                "deposit": "0.1"
            }
        ]
    }
}' prepaid-gas '100.0 Tgas' attached-deposit '1 yoctoNEAR' sign-as executor.testnet network-config testnet

Step 3: Voting on the Request

Once the request is submitted, members of the multisig contract have a set amount of time to vote to either Confirm or Reject the request. Each member needs to cast their vote using the following command:

near contract call-function as-transaction multisignature.testnet confirm json-args '{"request_id": 1}' prepaid-gas '100.0 Tgas' attached-deposit '1 yoctoNEAR' sign-as account.testnet network-config testnet

note

Replace provided request_id with value retrieved from the response when creating the request

Once the request has received enough confirmations, it will be automatically executed. At this point, the signature request is successfully registered on the Multi-Chain DAO Governance Contract.

info

Response example returned by Multi-chain DAO Contract

{
  "allowed_account_id": "denbite.testnet",
  "deadline": 1728986555728267025,
  "derivation_path": "denbite.testnet-0",
  "mpc_account_id": "v1.signer-prod.testnet",
  "request_id": 1
}

Please pay attention to deadline field, which represents the Unix timestamp in the future until which the get_signature function is allowed to be executed. Usually, the window is 24 hours after the signature request is registered.

Now, the allowed account (specified in the request) can generate signatures for the transaction.

Step 4: Signing the Transaction For Different Chain IDs

To sign a transaction for a specific chain, the following command can be used

near contract call-function as-transaction abstract-dao.testnet get_signature json-args '{
    "request_id": 1,
    "other_payload": {
        "chain_id": 11155111,
        "max_fee_per_gas": "1000000000",
        "max_priority_fee_per_gas": "100000000"
    }
}' prepaid-gas '300.0 Tgas' attached-deposit '0.05 NEAR' sign-as executor.testnet network-config testnet

note

• Replace provided request_id with value returned from register_signature_request function (see the response example above).
• Replace provided chain_id with destination chain that best fits your case (in this example 11155111 stands for Sepolia Testnet)

info

Signature response is going to look similar to the following

{
  "signature": {
    "big_r": {
      "affine_point": "02D532992B0ECBF67800DB14E04530D9BA55609AD31213CC7ABDB554E8FDA986D3"
    },
    "recovery_id": 1,
    "s": {
      "scalar": "40E81711B8174712B9F34B2540EE0F642802387D15543CBFC84211BB04B83AC3"
    }
  },
  "tx": "0x02f85083aa36a702850485034c878517a4eb0789829dd094e2a01146fffc8432497ae49a7a6cba5b9abd71a380a460fe47b1000000000000000000000000000000000000000000000000000000000000a84bc0"
}