Sign and Broadcast Transaction

There are two ways to sign and broadcast a transaction to the Ethereum network to stake MATIC.

Using a single piece of code.
Using a code to sign the transaction and then broadcasting it with an API method.

Using code

Retrieve an unsigned serialized transaction from the relevant API endpoint, e.g., staking/approve, staking/delegate, staking/unstake.
Sign and broadcast the transaction using the following code. The code example uses ethers.js 6.10.0.

require("dotenv").config();
const { ethers } = require('ethers');

async function signAndBroadcast() {
    console.log("Started");

    // Enter the serialized transaction
    const rawTransaction = process.env.RAW_TRANSACTION;

    // Enter the private key of the address used to transfer the stake amount
    const privateKey = process.env.PRIVATE_KEY;

    // Enter the selected RPC URL
    const rpcURL = process.env.RPC_URL;

    // Initialize the provider using the RPC URL
    const provider = new ethers.JsonRpcProvider(rpcURL);

    // Initialize a new Wallet instance
    const wallet = new ethers.Wallet(privateKey, provider);

    // Parse the raw transaction
    const tx = ethers.Transaction.from(rawTransaction);

    const newTx = {
        to: tx.to,
        data: tx.data,
        chainId: tx.chainId,
        value: tx.value,
        gasLimit: tx.gasLimit,
        type: 2,

        nonce: await provider.getTransactionCount(wallet.address),
        // Enter the max fee per gas and prirorty fee
        maxFeePerGas: ethers.parseUnits(process.env.MAX_FEE_PER_GAS_IN_GWEI, 'gwei'),
        maxPriorityFeePerGas: ethers.parseUnits(process.env.MAX_PRIORITY_FEE_IN_GWEI, 'gwei')
    }

    // Sign the transaction
    const signedTransaction = await wallet.signTransaction(newTx);

    // Send the signed transaction
    const transactionResponse = await provider.broadcastTransaction(signedTransaction);

    return transactionResponse;
}

signAndBroadcast()
    .then((transactionResponse) => {
        console.log(
            "Transaction broadcasted, transaction hash:",
            transactionResponse.hash
        );
    })
    .catch((error) => {
        console.error("Error:", error);
    })
    .finally(() => {
        console.log("Finished");
    });

Using code and API

1. Prepare and sign the transaction

Retrieve an unsigned serialized transaction from the relevant API endpoint, e.g., staking/approve, staking/delegate, staking/unstake.
Sign the transaction using the following code:


require("dotenv").config();
const { ethers } = require('ethers');

async function signAndBroadcast() {
    console.log("Started");

    // Enter the serialized transaction
    const rawTransaction = process.env.RAW_TRANSACTION;

    // Enter the private key of the address used to transfer the stake amount
    const privateKey = process.env.PRIVATE_KEY;

    // Enter the selected RPC URL
    const rpcURL = process.env.RPC_URL;

    // Initialize the provider using the RPC URL
    const provider = new ethers.JsonRpcProvider(rpcURL);

    // Initialize a new Wallet instance
    const wallet = new ethers.Wallet(privateKey, provider);

    // Parse the raw transaction
    const tx = ethers.Transaction.from(rawTransaction);

    const newTx = {
        to: tx.to,
        data: tx.data,
        chainId: tx.chainId,
        value: tx.value,
        gasLimit: tx.gasLimit,
        type: 2,

        nonce: await provider.getTransactionCount(wallet.address),
        // Enter the max fee per gas and prirorty fee
        maxFeePerGas: ethers.parseUnits(process.env.MAX_FEE_PER_GAS_IN_GWEI, 'gwei'),
        maxPriorityFeePerGas: ethers.parseUnits(process.env.MAX_PRIORITY_FEE_IN_GWEI, 'gwei')
    }

    // Sign the transaction
    const signedTransaction = await wallet.signTransaction(newTx);


    return signedTransaction;
}

signAndBroadcast()
    .then((signedTransaction) => {
        console.log(
            "Signed transaction is",
            signedTransaction
        );
    })
    .catch((error) => {
        console.error("Error:", error);
    })
    .finally(() => {
        console.log("Finished");
    });

3. Broadcast the transaction

Send the signed transaction to the Ethereum network by making a POST request to /api/v1/polygon/transaction/send.

Example request:

curl --request POST \
		 --url https://api.p2p.org/api/v1/polygon/transaction/send \
     --head 'accept: application/json' \
     --head 'Authorization: Bearer <token>' \
     --head 'Content-Type: application/json' \
     --data '
{
  "signedTransaction": "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",
  "stakerAddress": "0x39D02C253dA1d9F85ddbEB3B6Dc30bc1EcBbFA17"
}
'

signedTransaction — serialized signed transaction.
stakerAddress — staker account address.

Using code

Using code and API

1. Prepare and sign the transaction

3. Broadcast the transaction

What's next?