> ## Documentation Index
> Fetch the complete documentation index at: https://docs.peaq.xyz/llms.txt
> Use this file to discover all available pages before exploring further.

# Submitting Transactions

Submitting transactions is a core task when interacting with blockchains, like peaq. Transactions include **transferring funds**, **interacting with smart contracts**, or **deploying contracts**.
A transaction is required each time we want to **write data** to the blockchain and it's the responsibility of the developer to construct the transaction call data. This guide provides a
structured approach to submitting transactions using `ethers.js`, ensuring efficiency and security.

## Prerequisites

Before following the instructions, ensure the following:

1. **Environment Setup**:
   * **Node.js** and **npm** (or pnpm/yarn) are installed.
   * Ethers.js library is installed: `npm install ethers`.
2. **Account Setup**:
   * You have access to a private key or a connected **wallet** (e.g., MetaMask).
   * Your wallet has sufficient funds for **gas** fees.
3. **Blockchain Setup**:
   * You know the URL of the RPC you're interacting with.
   * You understand the transaction details, including recipient address, value, and any data (if applicable).
4. **Security Awareness**:
   * Never expose your private key or mnemonic in your code.
   * Use environment variables for sensitive information.

## Instructions

### 1. Install and Import ethers.js

In your JavaScript file, import ethers.js:

```javascript theme={"theme":{"light":"github-light-default","dark":"github-dark"}}
import { ethers } from 'ethers';
```

### 2. Set Up a Provider

Connect to an Ethereum-compatible network:

```javascript theme={"theme":{"light":"github-light-default","dark":"github-dark"}}
const provider = new ethers.JsonRpcProvider(HTTPS_URL);
```

### 3. Configure a Signer

Create a wallet instance to sign transactions:

```javascript theme={"theme":{"light":"github-light-default","dark":"github-dark"}}
const privateKey = process.env.PRIVATE_KEY; //Please store private keys in environment variables
const wallet = new ethers.Wallet(privateKey, provider);
```

### 4. Define the Transaction

Set up the transaction details:

```javascript theme={"theme":{"light":"github-light-default","dark":"github-dark"}}
const tx = {
  to: "0xRecipientAddressHere", // Replace with the recipient's address
  value: ethers.parseEther("0.1"), // Amount in ETH to send (converted from Ether)
  gasLimit: 21000, // Gas limit (for simple transfers)
  maxFeePerGas: ethers.parseUnits("20", "gwei"), // Max fee per gas
  maxPriorityFeePerGas: ethers.parseUnits("2", "gwei"), // Priority fee
};
```

For interacting with smart contracts, include `data` in the transaction object.

### 5. Sign and Submit the Transaction

Sign and send the transaction:

```javascript theme={"theme":{"light":"github-light-default","dark":"github-dark"}}
async function sendTransaction() {
  try {
    const txResponse = await wallet.sendTransaction(tx);
    console.log("Transaction submitted:", txResponse.hash);
    const receipt = await txResponse.wait();
    console.log("Transaction mined:", receipt);
  } catch (error) {
    console.error("Error submitting transaction:", error);
  }
}

sendTransaction();
```

### 6. Verify the Transaction

Monitor the transaction using the `txResponse.hash` in a block explorer or programmatically check its status using the `provider.getTransactionReceipt` method.

## Notes

* **Gas Estimation**: For more complex transactions, calculate gas estimates using `contract.estimateGas.methodName()`.
* **Smart Contracts**: For interacting with contracts, set up the contract instance using its ABI and address:

```javascript theme={"theme":{"light":"github-light-default","dark":"github-dark"}}
const contract = new ethers.Contract(contractAddress, contractABI, wallet);
```

## Putting it all Together

Here's a complete boilerplate script that ties together all the steps for submitting a transaction using `ethers.js`. This script includes environment variable handling, transaction setup, and submission.

<CodeGroup>
  ```javascript JavaScript theme={"theme":{"light":"github-light-default","dark":"github-dark"}}
  // Import ethers.js
  import { ethers } from 'ethers';
  require("dotenv").config(); // To use environment variables

  // Boilerplate Script
  async function main() {
    try {
      // Step 1: Set up the provider
      const rpcUrl = process.env.RPC_URL; // RPC URL for your blockchain
      if (!rpcUrl) throw new Error("RPC_URL is not defined in .env");
      const provider = new ethers.JsonRpcProvider(rpcUrl);

      // Step 2: Configure the wallet (signer)
      const privateKey = process.env.PRIVATE_KEY; // Private key stored in environment variables
      if (!privateKey) throw new Error("PRIVATE_KEY is not defined in .env");
      const wallet = new ethers.Wallet(privateKey, provider);

      console.log(`Connected wallet: ${wallet.address}`);

      // Step 3: Define the transaction
      const tx = {
        to: "0xRecipientAddressHere", // Replace with the recipient's address
        value: ethers.parseEther("0.1"), // Amount in ETH to send (e.g., 0.1 ETH)
        gasLimit: 21000, // Standard gas limit for a simple ETH transfer
        maxFeePerGas: ethers.parseUnits("20", "gwei"), // Max fee per gas
        maxPriorityFeePerGas: ethers.parseUnits("2", "gwei"), // Priority fee
      };

      console.log("Prepared transaction:", tx);

      // Step 4: Sign and send the transaction
      console.log("Sending transaction...");
      const txResponse = await wallet.sendTransaction(tx);
      console.log(`Transaction submitted: ${txResponse.hash}`);

      // Step 5: Wait for transaction to be mined
      console.log("Waiting for transaction to be mined...");
      const receipt = await txResponse.wait();
      console.log("Transaction mined:", receipt);

      console.log(`Transaction successful! Block Number: ${receipt.blockNumber}`);
    } catch (error) {
      console.error("Error occurred:", error.message);
    }
  }

  // Execute the script
  main();

  ```
</CodeGroup>

### Instructions for Using the Boilerplate Script

1. **Install Dependencies**:
   Ensure you have the required packages installed:

```bash theme={"theme":{"light":"github-light-default","dark":"github-dark"}}
npm install ethers dotenv
```

2. **Set ESM Module:**
   Add the following to your `package.json` to alllow for ESM modules.

```javascript theme={"theme":{"light":"github-light-default","dark":"github-dark"}}
"type": "module",
```

3. **Set Up Environment Variables**:
   Create a `.env` file in the root directory of your project with the following keys:

```bash theme={"theme":{"light":"github-light-default","dark":"github-dark"}}
RPC_URL=https://quicknode.peaq.xyz
PRIVATE_KEY=your-private-key
```

4. **Run the Script**:
   Execute the script in your terminal:

```bash theme={"theme":{"light":"github-light-default","dark":"github-dark"}}
node script.js
```

5. **Modify Transaction Details**:
   * Replace `0xRecipientAddressHere` with the recipient's address.
   * Adjust `value`, `maxFeePerGas`, and `maxPriorityFeePerGas` as needed.