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Libraries

Ethers.js

Ethers.js JavaScript Library

Introduction

The Ethers.js library provides a set of tools to interact with Ethereum Nodes with JavaScript, similar to Web3.js. Phron has an Ethereum-like API available that is fully compatible with Ethereum-style JSON-RPC invocations. Therefore, developers can leverage this compatibility and use the Ethers.js library to interact with a Phron node as if they were doing so on Ethereum. For more information on Ethers.js, check their documentation site.

In this guide, you'll learn how to use the Ethers.js library to send a transaction and deploy a contract on Phron.

Checking Prerequisites

For the examples in this guide, you will need to have the following:

An account with funds. You can get DEV tokens for testing on Phron once every 24 hours from the Phron Faucet
To test out the examples in this guide on Phron, you will need to have your own endpoint and API key, which you can get from one of the supported Endpoint Providers

Note
The examples in this guide assume you have a MacOS or Ubuntu 22.04-based environment and will need to be adapted accordingly for Windows.

Installing Ethers.js

To get started, you'll need to start a basic JavaScript project. First, create a directory to store all of the files you'll be creating throughout this guide and initialize the project with the following command:

mkdir ethers-examples && cd ethers-examples && npm init --y

For this guide, you'll need to install the Ethers.js library and the Solidity compiler. To install both NPM packages, you can run the following command:

npm install ethers solc@0.8.0

Setting up the Ethers Provider

Throughout this guide, you'll be creating a bunch of scripts that provide different functionality such as sending a transaction, deploying a contract, and interacting with a deployed contract. In most of these scripts you'll need to create an Ethers provider to interact with the network.

To configure your project for Phron, you will need to have your own endpoint and API key, which you can get from one of the supported Endpoint Providers.

To create a provider, you can take the following steps:

Import the ethers library
Define the providerRPC object, which can include the network configurations for any of the networks you want to send a transaction on. You'll include the name, rpc, and chainId for each network
Create the provider using the ethers.JsonRpcProvider method

// 1. Import ethers
const ethers = require('ethers');

// 2. Define network configurations
const providerRPC = {
  phron: {
    name: 'phron',
    rpc: 'INSERT_RPC_API_ENDPOINT', // Insert your RPC URL here
    chainId: 7744, // 0x504 in hex,
  },
};
// 3. Create ethers provider
const provider = new ethers.JsonRpcProvider(providerRPC.phron.rpc, {
  chainId: providerRPC.phron.chainId,
  name: providerRPC.phron.name,
});

Save this code snippet as you'll need it for the scripts that are used in the following sections.

Send a Transaction

During this section, you'll be creating a couple of scripts. The first one will be to check the balances of your accounts before trying to send a transaction. The second script will actually send the transaction.

You can also use the balance script to check the account balances after the transaction has been sent.

Check Balances Script

You'll only need one file to check the balances of both addresses before and after the transaction is sent. To get started, you can create a balances.js file by running:

touch balances.js

Next, you will create the script for this file and complete the following steps:

Set up the Ethers provider
Define the addressFrom and addressTo variables
Create the asynchronous balances function which wraps the provider.getBalance method
Use the provider.getBalance function to fetch the balances for the addressFrom and addressTo addresses. You can also leverage the ethers.formatEther function to transform the balance into a more readable number in ETH
Lastly, run the balances function

// 1. Add the Ethers provider logic here:
// {...}

// 2. Create address variables
const addressFrom = 'INSERT_FROM_ADDRESS';
const addressTo = 'INSERT_TO_ADDRESS';

// 3. Create balances function
const balances = async () => {
  // 4. Fetch balances
  const balanceFrom = ethers.formatEther(await provider.getBalance(addressFrom));
  const balanceTo = ethers.formatEther(await provider.getBalance(addressTo));

  console.log(`The balance of ${addressFrom} is: ${balanceFrom} DEV`);
  console.log(`The balance of ${addressTo} is: ${balanceTo} DEV`);
};

// 5. Call the balances function
balances();

View the complete script

// Import ethers
const ethers = require('ethers');

// Define network configurations
const providerRPC = {
  development: {
    name: 'phron-development',
    rpc: 'http://localhost:9944',
    chainId: 7744,
  },
  phron: {
    name: 'phron',
    rpc: 'https://testnet.phron.ai',
    chainId: 7744,
  },
};

// Create ethers provider
const provider = new ethers.JsonRpcProvider(providerRPC.phron.rpc, {
  chainId: providerRPC.phron.chainId,
  name: providerRPC.phron.name,
}); // Change to correct network

// Define addresses
const addressFrom = 'INSERT_FROM_ADDRESS';
const addressTo = 'INSERT_TO_ADDRESS';

// Create balances function
const balances = async () => {
  // Fetch balances
  const balanceFrom = ethers.formatEther(
    await provider.getBalance(addressFrom)
  );
  const balanceTo = ethers.formatEther(await provider.getBalance(addressTo));

  console.log(`The balance of ${addressFrom} is: ${balanceFrom} DEV`);
  console.log(`The balance of ${addressTo} is: ${balanceTo} DEV`);
};

// Call the balances function
balances();

To run the script and fetch the account balances, you can run the following command:

node balances.js

If successful, the balances for the origin and receiving address will be displayed in your terminal in DEV.

Send Transaction Script

You'll only need one file for executing a transaction between accounts. For this example, you'll be transferring 1 DEV token from an origin address (from which you hold the private key) to another address. To get started, you can create a transaction.js file by running:

touch transaction.js

Next, you will create the script for this file and complete the following steps:

Set up the Ethers provider
Define the privateKey and the addressTo variables. The private key is required to create a wallet instance. Note: This is for example purposes only. Never store your private keys in a JavaScript file
Create a wallet using the privateKey and provider from the previous steps. The wallet instance is used to sign transactions
Create the asynchronous send function which wraps the transaction object and the wallet.sendTransaction method
Create the transaction object which only requires the recipient's address and the amount to send. Note that ethers.parseEther can be used, which handles the necessary unit conversions from Ether to Wei - similar to using ethers.parseUnits(value, 'ether')
Send the transaction using the wallet.sendTransaction method and then use await to wait until the transaction is processed and the transaction receipt is returned
Lastly, run the send function

// 1. Add the Ethers provider logic here:
// {...}

// 2. Create account variables
const accountFrom = {
  privateKey: 'INSERT_YOUR_PRIVATE_KEY',
};
const addressTo = 'INSERT_TO_ADDRESS';

// 3. Create wallet
let wallet = new ethers.Wallet(accountFrom.privateKey, provider);

// 4. Create send function
const send = async () => {
  console.log(`Attempting to send transaction from ${wallet.address} to ${addressTo}`);

  // 5. Create tx object
  const tx = {
    to: addressTo,
    value: ethers.parseEther('1'),
  };

  // 6. Sign and send tx - wait for receipt
  const createReceipt = await wallet.sendTransaction(tx);
  await createReceipt.wait();
  console.log(`Transaction successful with hash: ${createReceipt.hash}`);
};

// 7. Call the send function
send();

View the complete script

// Import ethers
const ethers = require('ethers');

// Define network configurations
const providerRPC = {
  development: {
    name: 'phron-development',
    rpc: 'http://localhost:9944',
    chainId: 7744,
  },
  phronbase: {
    name: 'phron',
    rpc: 'https://testnet.phron.ai',
    chainId: 7744,
  },
};
// Create ethers provider
const provider = new ethers.JsonRpcProvider(providerRPC.phron.rpc, {
  chainId: providerRPC.phron.chainId,
  name: providerRPC.phron.name,
}); // Change to correct network

// Define accounts and wallet
const accountFrom = {
  privateKey: 'INSERT_YOUR_PRIVATE_KEY',
};
const addressTo = 'INSERT_TO_ADDRESS';
const wallet = new ethers.Wallet(accountFrom.privateKey, provider);

// Create send function
const send = async () => {
  console.log(
    `Attempting to send transaction from ${wallet.address} to ${addressTo}`
  );

  // Create transaction
  const tx = {
    to: addressTo,
    value: ethers.parseEther('1'),
  };

  // Send transaction and get hash
  const createReceipt = await wallet.sendTransaction(tx);
  await createReceipt.wait();
  console.log(`Transaction successful with hash: ${createReceipt.hash}`);
};

// Call the send function
send();

To run the script, you can run the following command in your terminal:

node transaction.js

If the transaction was succesful, in your terminal you'll see the transaction hash has been printed out.

You can also use the balances.js script to check that the balances for the origin and receiving accounts have changed. The entire workflow would look like this:

node balances.jsThe balance of 0x3B939FeaD1557C741Ff06492FD0127bd287A421e is: 3604.673685275447543445 DEVThe balance of 0xFFA0352d300cdd8aCdA5c947D87CbCc3f0B3485A is: 0 DEVnode transaction.jsAttempting to send transaction from 0x3B939FeaD1557C741Ff06492FD0127bd287A421e to 0xFFA0352d300cdd8aCdA5c947D87CbCc3f0B3485ATransaction successful with hash: 0x01e42c627fe79b1d5649a64d39fceec34aba3904e37d768e74ec71fcd62b897fnode balances.jsThe balance of 0x3B939FeaD1557C741Ff06492FD0127bd287A421e is: 3603.673682650447543445 DEVThe balance of 0xFFA0352d300cdd8aCdA5c947D87CbCc3f0B3485A is: 1.0 DEV

Deploy a Contract

The contract you'll be compiling and deploying in the next couple of sections is a simple incrementer contract, arbitrarily named Incrementer.sol. You can get started by creating a file for the contract:

touch Incrementer.sol

Next, you can add the Solidity code to the file:

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

contract Incrementer {
    uint256 public number;

    constructor(uint256 _initialNumber) {
        number = _initialNumber;
    }

    function increment(uint256 _value) public {
        number = number + _value;
    }

    function reset() public {
        number = 0;
    }
}

The constructor function, which runs when the contract is deployed, sets the initial value of the number variable stored on-chain (the default is 0). The increment function adds the _value provided to the current number, but a transaction needs to be sent, which modifies the stored data. Lastly, the reset function resets the stored value to zero.

Note
This contract is a simple example for illustration purposes only and does not handle values wrapping around.

Compile Contract Script

In this section, you'll create a script that uses the Solidity compiler to output the bytecode and interface (ABI) for the Incrementer.sol contract. To get started, you can create a compile.js file by running:

touch compile.js

Next, you will create the script for this file and complete the following steps:

Import the fs and solc packages
Using the fs.readFileSync function, you'll read and save the file contents of Incrementer.sol to source
Build the input object for the Solidity compiler by specifying the language, sources, and settings to be used
Using the input object, you can compile the contract using solc.compile
Extract the compiled contract file and export it to be used in the deployment script

// 1. Import packages
const fs = require('fs');
const solc = require('solc');

// 2. Get path and load contract
const source = fs.readFileSync('Incrementer.sol', 'utf8');

// 3. Create input object
const input = {
   language: 'Solidity',
   sources: {
      'Incrementer.sol': {
         content: source,
      },
   },
   settings: {
      outputSelection: {
         '*': {
            '*': ['*'],
         },
      },
   },
};
// 4. Compile the contract
const tempFile = JSON.parse(solc.compile(JSON.stringify(input)));
const contractFile = tempFile.contracts['Incrementer.sol']['Incrementer'];

// 5. Export contract data
module.exports = contractFile;

Deploy Contract Script

With the script for compiling the Incrementer.sol contract in place, you can then use the results to send a signed transaction that deploys it. To do so, you can create a file for the deployment script called deploy.js:

touch deploy.js

Next, you will create the script for this file and complete the following steps:

Import the contract file from compile.js
Set up the Ethers provider
Define the privateKey for the origin account. The private key is required to create a wallet instance. Note: This is for example purposes only. Never store your private keys in a JavaScript file
Create a wallet using the privateKey and provider from the previous steps. The wallet instance is used to sign transactions
Load the contract bytecode and abi for the compiled contract
Create a contract instance with signer using the ethers.ContractFactory function, providing the abi, bytecode, and wallet as parameters
Create the asynchronous deploy function that will be used to deploy the contract
Within the deploy function, use the incrementer contract instance to call deploy and pass in the initial value. For this example, you can set the initial value to 5. This will send the transaction for contract deployment. To wait for a transaction receipt you can use the deployed method of the contract deployment transaction
Lastly, run the deploy function

// 1. Import the contract file
const contractFile = require('./compile');

// 2. Add the Ethers provider logic here:
// {...}

// 3. Create account variables
const accountFrom = {
  privateKey: 'INSERT_YOUR_PRIVATE_KEY',
};

// 4. Create wallet
let wallet = new ethers.Wallet(accountFrom.privateKey, provider);

// 5. Load contract information
const bytecode = contractFile.evm.bytecode.object;
const abi = contractFile.abi;

// 6. Create contract instance with signer
const incrementer = new ethers.ContractFactory(abi, bytecode, wallet);

// 7. Create deploy function
const deploy = async () => {
  console.log(`Attempting to deploy from account: ${wallet.address}`);

  // 8. Send tx (initial value set to 5) and wait for receipt
  const contract = await incrementer.deploy(5);
  const txReceipt = await contract.deploymentTransaction().wait();

  console.log(`Contract deployed at address: ${txReceipt.contractAddress}`);
};

// 9. Call the deploy function
deploy();

View the complete script

// Import ethers and compile
const ethers = require('ethers');
const contractFile = require('./compile');

// Define network configurations
const providerRPC = {
  development: {
    name: 'phron-development',
    rpc: 'http://localhost:9944',
    chainId: 7744,
  },
  phronbase: {
    name: 'phron',
    rpc: 'https://testnet.phron.ai',
    chainId: 7744,
  },
};

// Create ethers provider
const provider = new ethers.JsonRpcProvider(providerRPC.phron.rpc, {
  chainId: providerRPC.phron.chainId,
  name: providerRPC.phron.name,
}); // Change to correct network

// Define accounts and wallet
const accountFrom = {
  privateKey: 'INSERT_YOUR_PRIVATE_KEY',
};
let wallet = new ethers.Wallet(accountFrom.privateKey, provider);

// Load contract info
const bytecode = contractFile.evm.bytecode.object;
const abi = contractFile.abi;

// Create contract instance with signer
const incrementer = new ethers.ContractFactory(abi, bytecode, wallet);

// Create deploy function
const deploy = async () => {
  console.log(`Attempting to deploy from account: ${wallet.address}`);

  // Send tx (initial value set to 5) and wait for receipt
  const contract = await incrementer.deploy(5);
  const txReceipt = await contract.deploymentTransaction().wait();

  console.log(`Contract deployed at address: ${txReceipt.contractAddress}`);
};

// Call the deploy function
deploy();

To run the script, you can enter the following command into your terminal:

node deploy.js

If successful, the contract's address will be displayed in the terminal.

node deploy.jsAttempting to deploy from account: 0x3B939FeaD1557C741Ff06492FD0127bd287A421eContract deployed at address: 0x2B9c71fc2730B7353Dd3865ae26881Fa38FE598A

Read Contract Data (Call Methods)

Call methods are the type of interaction that don't modify the contract's storage (change variables), meaning no transaction needs to be sent. They simply read various storage variables of the deployed contract.

To get started, you can create a file and name it get.js:

touch get.js

Then you can take the following steps to create the script:

Import the abi from the compile.js file
Set up the Ethers provider
Create the contractAddress variable using the address of the deployed contract
Create an instance of the contract using the ethers.Contract function and passing in the contractAddress, abi, and provider
Create the asynchronous get function
Use the contract instance to call one of the contract's methods and pass in any inputs if necessary. For this example, you will call the number method which doesn't require any inputs. You can use await which will return the value requested once the request promise resolves
Lastly, call the get function

// 1. Import the ABI
const { abi } = require('./compile');

// 2. Add the Ethers provider logic here:
// {...}

// 3. Contract address variable
const contractAddress = 'INSERT_CONTRACT_ADDRESS';

// 4. Create contract instance
const incrementer = new ethers.Contract(contractAddress, abi, provider);

// 5. Create get function
const get = async () => {
  console.log(`Making a call to contract at address: ${contractAddress}`);

  // 6. Call contract 
  const data = await incrementer.number();

  console.log(`The current number stored is: ${data}`);
};

// 7. Call get function
get();

View the complete script

// Import ethers and compile
const ethers = require('ethers');
const { abi } = require('./compile');

// Define network configurations
const providerRPC = {
  development: {
    name: 'phron-development',
    rpc: 'http://localhost:9944',
    chainId: 7744,
  },
  phronbase: {
    name: 'phron',
    rpc: 'https://testnet.phron.ai',
    chainId: 7744,
  },
};

const provider = new ethers.JsonRpcProvider(providerRPC.phron.rpc, {
  chainId: providerRPC.phron.chainId,
  name: providerRPC.phron.name,
}); // Change to correct network

// Contract address variable
const contractAddress = 'INSERT_CONTRACT_ADDRESS';

// Create contract instance
const incrementer = new ethers.Contract(contractAddress, abi, provider);

// Create get function
const get = async () => {
  console.log(`Making a call to contract at address: ${contractAddress}`);

  // Call contract
  const data = await incrementer.number();

  console.log(`The current number stored is: ${data}`);
};

// Call get function
get();

To run the script, you can enter the following command in your terminal:

node get.js

If successful, the value will be displayed in the terminal.

Interact with Contract (Send Methods)

Send methods are the type of interaction that modify the contract's storage (change variables), meaning a transaction needs to be signed and sent. In this section, you'll create two scripts: one to increment and one to reset the incrementer. To get started, you can create a file for each script and name them increment.js and reset.js:

touch increment.js reset.js

Open the increment.js file and take the following steps to create the script:

Import the abi from the compile.js file
Set up the Ethers provider
Define the privateKey for the origin account, the contractAddress of the deployed contract, and the _value to increment by. The private key is required to create a wallet instance. Note: This is for example purposes only. Never store your private keys in a JavaScript file
Create a wallet using the privateKey and provider from the previous steps. The wallet instance is used to sign transactions
Create an instance of the contract using the ethers.Contract function and passing in the contractAddress, abi, and provider
Create the asynchronous increment function
Use the contract instance to call one of the contract's methods and pass in any inputs if necessary. For this example, you will call the increment method which requires the value to increment by as an input. You can use await which will return the value requested once the request promise resolves
Lastly, call the increment function

// 1. Import the contract ABI
const { abi } = require('./compile');

// 2. Add the Ethers provider logic here:
// {...}

// 3. Create variables
const accountFrom = {
  privateKey: 'INSERT_YOUR_PRIVATE_KEY',
};
const contractAddress = 'INSERT_CONTRACT_ADDRESS';
const _value = 3;

// 4. Create wallet
let wallet = new ethers.Wallet(accountFrom.privateKey, provider);

// 5. Create contract instance with signer
const incrementer = new ethers.Contract(contractAddress, abi, wallet);

// 6. Create increment function
const increment = async () => {
  console.log(
    `Calling the increment by ${_value} function in contract at address: ${contractAddress}`
  );

  // 7. Sign and send tx and wait for receipt
  const createReceipt = await incrementer.increment(_value);
  await createReceipt.wait();

  console.log(`Tx successful with hash: ${createReceipt.hash}`);
};

// 8. Call the increment function
increment();

View the complete script

// Import ethers and compile
const ethers = require('ethers');
const { abi } = require('./compile');

// Define network configurations
const providerRPC = {
  development: {
    name: 'phron-development',
    rpc: 'http://localhost:9944',
    chainId: 7744,
  },
  phronbase: {
    name: 'phron',
    rpc: 'https://testnet.phron.ai',
    chainId: 7744,
  },
};

// Create ethers provider
const provider = new ethers.JsonRpcProvider(providerRPC.phron.rpc, {
  chainId: providerRPC.phron.chainId,
  name: providerRPC.phron.name,
}); // Change to correct network

// Create variables
const accountFrom = {
  privateKey: 'INSERT_YOUR_PRIVATE_KEY',
};
const contractAddress = 'INSERT_CONTRACT_ADDRESS';
const _value = 3;

// Create wallet
let wallet = new ethers.Wallet(accountFrom.privateKey, provider);

// Create contract instance with signer
const incrementer = new ethers.Contract(contractAddress, abi, wallet);

// Create reset function
const increment = async () => {
  console.log(
    `Calling the increment by ${_value} function in contract at address: ${contractAddress}`
  );

  // Sign and send tx and wait for receipt
  const createReceipt = await incrementer.increment(_value);
  await createReceipt.wait();

  console.log(`Tx successful with hash: ${createReceipt.hash}`);
};

// Call the reset function
increment();

To run the script, you can enter the following command in your terminal:

node increment.js

If successful, the transaction hash will be displayed in the terminal. You can use the get.js script alongside the increment.js script to make sure that value is changing as expected:

node get.jsMaking a call to contract at address: 0x2B9c71fc2730B7353Dd3865ae26881Fa38FE598AThe current number stored is: 5node increment.jsCalling the increment by 3 function in contract at address: 0x2B9c71fc2730B7353Dd3865ae26881Fa38FE598ATx successful with hash: 0xc7fe935db03cfacf56c5649cd79a566d1a7b68417f904f0095a1b1c203875bf2node get.jsMaking a call to contract at address: 0x2B9c71fc2730B7353Dd3865ae26881Fa38FE598AThe current number stored is: 8

Next you can open the reset.js file and take the following steps to create the script:

Import the abi from the compile.js file
Set up the Ethers provider
Define the privateKey for the origin account and the contractAddress of the deployed contract. The private key is required to create a wallet instance. Note: This is for example purposes only. Never store your private keys in a JavaScript file
Create a wallet using the privateKey and provider from the previous steps. The wallet instance is used to sign transactions
Create an instance of the contract using the ethers.Contract function and passing in the contractAddress, abi, and provider
Create the asynchronous reset function
Use the contract instance to call one of the contract's methods and pass in any inputs if necessary. For this example, you will call the reset method which doesn't require any inputs. You can use await which will return the value requested once the request promise resolves
Lastly, call the reset function

// 1. Import the contract ABI
const { abi } = require('./compile');

// 2. Add the Ethers provider logic here:
// {...}

// 3. Create variables
const accountFrom = {
  privateKey: 'INSERT_YOUR_PRIVATE_KEY',
};
const contractAddress = 'INSERT_CONTRACT_ADDRESS';

// 4. Create wallet
let wallet = new ethers.Wallet(accountFrom.privateKey, provider);

// 5. Create contract instance with signer
const incrementer = new ethers.Contract(contractAddress, abi, wallet);

// 6. Create reset function
const reset = async () => {
  console.log(
    `Calling the reset function in contract at address: ${contractAddress}`
  );

  // 7. sign and send tx and wait for receipt
  const createReceipt = await incrementer.reset();
  await createReceipt.wait();

  console.log(`Tx successful with hash: ${createReceipt.hash}`);
};

// 8. Call the reset function
reset();

View the complete script

// Import ethers and compile
const ethers = require('ethers');
const { abi } = require('./compile');

// Define network configurations
const providerRPC = {
  development: {
    name: 'phron-development',
    rpc: 'http://localhost:9944',
    chainId: 7744,
  },
  phron: {
    name: 'phron',
    rpc: 'https://testnet.phron.ai',
    chainId: 7744,
  },
};

// Create ethers provider
const provider = new ethers.JsonRpcProvider(providerRPC.phron.rpc, {
  chainId: providerRPC.phron.chainId,
  name: providerRPC.phron.name,
}); // Change to correct network

// Create variables
const accountFrom = {
  privateKey: 'INSERT_YOUR_PRIVATE_KEY',
};
const contractAddress = 'INSERT_CONTRACT_ADDRESS';

// Create wallet
let wallet = new ethers.Wallet(accountFrom.privateKey, provider);

// Create contract instance with signer
const incrementer = new ethers.Contract(contractAddress, abi, wallet);

// Create reset function
const reset = async () => {
  console.log(
    `Calling the reset function in contract at address: ${contractAddress}`
  );

  // Sign and send tx and wait for receipt
  const createReceipt = await incrementer.reset();
  await createReceipt.wait();

  console.log(`Tx successful with hash: ${createReceipt.hash}`);
};

// Call the reset function
reset();

To run the script, you can enter the following command in your terminal:

node reset.js

If successful, the transaction hash will be displayed in the terminal. You can use the get.js script alongside the reset.js script to make sure that value is changing as expected:

node get.jsMaking a call to contract at address: 0x2B9c71fc2730B7353Dd3865ae26881Fa38FE598AThe current number stored is: 8node reset.jsCalling the reset function in contract at address: 0x2B9c71fc2730B7353Dd3865ae26881Fa38FE598ATx successful with hash: 0xc452d21d8c2be6b81aadab7414103d68149c94a6399149ab8b79a58f0a3b5db7node get.jsMaking a call to contract at address: 0x2B9c71fc2730B7353Dd3865ae26881Fa38FE598AThe current number stored is: 0

This tutorial is for educational purposes only. As such, any contracts or code created in this tutorial should not be used in production.The information presented herein has been provided by third parties and is made available solely for general information purposes. Phron does not endorse any project listed and described on the Phron Doc Website (https://docs.Phron.ai/). Phron does not warrant the accuracy, completeness or usefulness of this information. Any reliance you place on such information is strictly at your own risk. Phron disclaims all liability and responsibility arising from any reliance placed on this information by you or by anyone who may be informed of any of its contents. All statements and/or opinions expressed in these materials are solely the responsibility of the person or entity providing those materials and do not necessarily represent the opinion of Phron. The information should not be construed as professional or financial advice of any kind. Advice from a suitably qualified professional should always be sought in relation to any particular matter or circumstance. The information herein may link to or integrate with other websites operated or content provided by third parties, and such other websites may link to this website. Phron has no control over any such other websites or their content and will have no liability arising out of or related to such websites or their content. The existence of any such link does not constitute an endorsement of such websites, the content of the websites, or the operators of the websites. These links are being provided to you only as a convenience and you release and hold Phron harmless from any and all liability arising from your use of this information or the information provided by any third-party website or service.

Ethers.rs

Ethers.rs Rust Library

Introduction

The Ethers.rs library provides a set of tools to interact with Ethereum Nodes via the Rust programming language that works similar to Ethers.js. Phron has an Ethereum-like API available that is fully compatible with Ethereum-style JSON-RPC invocations. Therefore, developers can leverage this compatibility and use the Ethers.rs library to interact with a Phron node as if they were doing so on Ethereum. You can read more about how to use Ethers.rs on their official crate documentation.

In this guide, you'll learn how to use the Ethers.rs library to send a transaction and deploy a contract on Phron.

Checking Prerequisites

For the examples in this guide, you will need to have the following:

An account with funds. You can get DEV tokens for testing on Phron once every 24 hours from the Phron Faucet
To test out the examples in this guide on Phron, you will need to have your own endpoint and API key, which you can get from one of the supported Endpoint Providers
Have Rust installed on your device
Have solc installed on your device. Using solc-select is recommended by the Ethers.rs package

Note
The examples in this guide assumes you have a MacOS or Ubuntu 20.04-based environment and will need to be adapted accordingly for Windows.

Create a Rust Project

To get started, you can create a new Rust project with the Cargo tool:

cargo init ethers-examples && cd ethers-examples

For this guide, you'll need to install the Ethers.rs library among others. To tell the Rust project to install it, you must edit the Cargo.toml file that's included with the document to include it under dependencies:

[package]
name = "ethers-examples"
version = "0.1.0"
edition = "2021"

[dependencies]
ethers = "1.0.2"
ethers-solc = "1.0.2"
tokio = { version = "1", features = ["full"] }
serde_json = "1.0.89"
serde = "1.0.149"

This example is using the ethers and ethers-solc crate versions 1.0.2 for RPC interactions and Solidity compiling. It also includes the tokio crate to run asynchronous Rust environments, since interacting with RPCs requires asynchronous code. Finally, it includes the serde_json and serde crates to help serialize/deserialize this example's code.

If this is your first time using solc-select, you'll need to install and configure the Solidity version using the following commands:

solc-select install 0.8.17 && solc-select use 0.8.17

Setting up the Ethers Provider and Client

Throughout this guide, you'll be writing multiple functions that provide different functionality such as sending a transaction, deploying a contract, and interacting with a deployed contract. In most of these scripts you'll need to use an Ethers provider or an Ethers signer client to interact with the network.

To configure your project for Phron, you will need to have your own endpoint and API key, which you can get from one of the supported Endpoint Providers.

There are multiple ways to create a provider and signer, but the easiest way is through try_from. In the src/main.rs file, you can take the following steps:

Import Provider and Http from the ethers crate
Add a Client type for convenience, which will be used once you start to create the functions for sending a transaction and deploying a contract
Add a tokio attribute above async fn main() for asynchronous excution
Use try_from to attempt to instantiate a JSON-RPC provider object from an RPC endpoint
Use a private key to create a wallet object (the private key will be used to sign transactions). Note: This is for example purposes only. Never store your private keys in a plain Rust file
Wrap the provider and wallet together into a client by providing them to a SignerMiddleware object

// 1. Import ethers crate
use ethers::providers::{Provider, Http};

// 2. Add client type
type Client = SignerMiddleware<Provider<Http>, Wallet<k256::ecdsa::SigningKey>>;

// 3. Add annotation
#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    // 4. Use try_from with RPC endpoint
    let provider = Provider::<Http>::try_from(
        "INSERT_RPC_API_ENDPOINT"
    )?;
    // 5. Use a private key to create a wallet
    // Do not include the private key in plain text in any production code
    // This is just for demonstration purposes
    // Do not include '0x' at the start of the private key
    let wallet: LocalWallet = "INSERT_YOUR_PRIVATE_KEY"
        .parse::<LocalWallet>()?
        .with_chain_id(Chain::Phron);

    // 6. Wrap the provider and wallet together to create a signer client
    let client = SignerMiddleware::new(provider.clone(), wallet.clone());
    Ok(())
}

Send a Transaction

During this section, you'll be creating a couple of functions, which will be contained in the same main.rs file to avoid additional complexity from implementing modules. The first function will be to check the balances of your accounts before trying to send a transaction. The second function will actually send the transaction. To run each of these functions, you will edit the main function and run the main.rs script.

You should already have your provider and client set up in main.rs in the way described in the previous section. In order to send a transaction, you'll need to add a few more lines of code:

Add use ethers::{utils, prelude::*}; to your imports, which will provide you access to utility functions and the prelude imports all of the necessary data types and traits
As you'll be sending a transaction from one address to another, you can specify the sending and receiving addresses in the main function. Note: the address_from value should correspond to the private key that is used in the main function

// ...
// 1. Add to imports
use ethers::{utils, prelude::*};

// ...

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    // ...

    // 2. Add from and to address
    let address_from = "YOUR_FROM_ADDRESS".parse::<Address>()?
    let address_to = "YOUR_TO_ADDRESS".parse::<Address>()?
}

Check Balances Function

Next, you will create the function for getting the sending and receiving accounts' balances by completing the following steps:

Create a new asynchronous function named print_balances that takes a provider object's reference and the sending and receiving addresses as input
Use the provider object's get_balance function to get the balances of the sending and receiving addresses of the transaction
Print the resultant balances for the sending and receiving addresses
Call the print_balances function in the main function

// ...

// 1. Create an asynchronous function that takes a provider reference and from and to address as input
async fn print_balances(provider: &Provider<Http>, address_from: Address, address_to: Address) -> Result<(), Box<dyn std::error::Error>> {
    // 2. Use the get_balance function
    let balance_from = provider.get_balance(address_from, None).await?;
    let balance_to = provider.get_balance(address_to, None).await?;

    // 3. Print the resultant balance
    println!("{} has {}", address_from, balance_from);
    println!("{} has {}", address_to, balance_to);

    Ok(())
}

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    // ...

    // 4. Call print_balances function in main
    print_balances(&provider).await?;

    Ok(())
}

Send Transaction Script

For this example, you'll be transferring 1 DEV from an origin address (of which you hold the private key) to another address.

Create a new asynchronous function named send_transaction that takes a client object's reference and the sending and receiving addresses as input
Create the transaction object, and include the to, value, and from. When writing the value input, use the ethers::utils::parse_ether function
Use the client object to send the transaction
Print the transaction after it is confirmed
Call the send_transaction function in the main function

// ...

// 1. Define an asynchronous function that takes a client provider and the from and to addresses as input
async fn send_transaction(client: &Client, address_from: Address, address_to: Address) -> Result<(), Box<dyn std::error::Error>> {
    println!(
        "Beginning transfer of 1 native currency from {} to {}.",
        address_from, address_to
    );

    // 2. Create a TransactionRequest object
    let tx = TransactionRequest::new()
        .to(address_to)
        .value(U256::from(utils::parse_ether(1)?))
        .from(address_from);

    // 3. Send the transaction with the client
    let tx = client.send_transaction(tx, None).await?.await?;

    // 4. Print out the result
    println!("Transaction Receipt: {}", serde_json::to_string(&tx)?);

    Ok(())
}

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    // ...

    // 5. Call send_transaction function in main
    send_transaction(&client, address_from, address_to).await?;

    Ok(())
}

View the complete script

use ethers::providers::{Provider, Http};
use ethers::{utils, prelude::*};

type Client = SignerMiddleware<Provider<Http>, Wallet<k256::ecdsa::SigningKey>>;

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let provider: Provider<Http> = Provider::<Http>::try_from("https://testnet.phron.ai")?; // Change to correct network
    // Do not include the private key in plain text in any production code. This is just for demonstration purposes
    let wallet: LocalWallet = "INSERT_PRIVATE_KEY"
        .parse::<LocalWallet>()?
        .with_chain_id(Chain::Phron);  // Change to correct network
    let client = SignerMiddleware::new(provider.clone(), wallet.clone());

    let address_from = "INSERT_FROM_ADDRESS".parse::<Address>()?;
    let address_to = "INSERT_TO_ADDRESS".parse::<Address>()?;

    send_transaction(&client, &address_from, &address_to).await?;
    print_balances(&provider, &address_from, &address_to).await?;

    Ok(())
}

// Print the balance of a wallet
async fn print_balances(provider: &Provider<Http>, address_from: &Address, address_to: &Address) -> Result<(), Box<dyn std::error::Error>> {
    let balance_from = provider.get_balance(address_from.clone(), None).await?;
    let balance_to = provider.get_balance(address_to.clone(), None).await?;

    println!("{} has {}", address_from, balance_from);
    println!("{} has {}", address_to, balance_to);
    Ok(())
}


// Sends some native currency
async fn send_transaction(client: &Client, address_from: &Address, address_to: &Address) -> Result<(), Box<dyn std::error::Error>> {
    println!(
        "Beginning transfer of 1 native currency {} to {}.",
        address_from, address_to
    );
    let tx = TransactionRequest::new()
        .to(address_to.clone())
        .value(U256::from(utils::parse_ether(1)?))
        .from(address_from.clone());
    let tx = client.send_transaction(tx, None).await?.await?;

    println!("Transaction Receipt: {}", serde_json::to_string(&tx)?);

    Ok(())
}

To run the script, which will send the transaction and then check the balances once the transaction has been sent, you can run the following command:

cargo run

If the transaction was succesful, in your terminal you'll see the transaction details printed out along with the balance of your address.

cargo runCompiling ethers-examples v0.1.0 (/Users/phron/workspace/ethers-examples)Finished dev [unoptimized + debuginfo] target(s) in 32.76sRunning `target/debug/ethers-examples`Beginning transfer of 1 native currency 0x3b93…421e to 0xe773…8dde.Transaction Receipt: {"transactionHash":"0x6f2338c63286f8b27951ddb6748191149d82647b44a00465f1f776624f490ce9","transactionIndex":"0x0","blockHash":"0x8234eb2083e649ab45c7c5fcdf2026d8f47676f7e29305023d1d00cc349ba215","blockNumber":"0x7ac12d","from":"0x3b939fead1557c741ff06492fd0127bd287a421e","to":"0xe773f740828a968c8a9e1e8e05db486937768dde","cumulativeGasUsed":"0x5208","gasUsed":"0x5208","contractAddress":null,"logs":[],"status":"0x1","logsBloom":"0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000","type":"0x0","effectiveGasPrice":"0x7735940"}0x3b93…421e has 36017039844708655891250xe773…8dde has 1000000000000000000

Deploy a Contract

touch Incrementer.sol

Next, you can add the Solidity code to the file:

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

contract Incrementer {
    uint256 public number;

    constructor(uint256 _initialNumber) {
        number = _initialNumber;
    }

    function increment(uint256 _value) public {
        number = number + _value;
    }

    function reset() public {
        number = 0;
    }
}

Note
This contract is a simple example for illustration purposes only and does not handle values wrapping around.

During the rest of this section, you'll be creating a couple of functions, which will be contained in the main.rs file to avoid additional complexity from implementing modules. The first function will be to compile and deploy the contract. The remaining functions will interact with the deployed contract.

You should already have your provider and client set up in main.rs in the way described in the Setting up the Ethers Provider and Client section.

Before getting started with the contract deployment, you'll need to add a few more imports to your main.rs file:

use ethers_solc::Solc;
use ethers::{prelude::*};
use std::{path::Path, sync::Arc};

The ethers_solc import will be used to compile the smart contract. The prelude from Ethers imports some necessary data types and traits. Lastly, the std imports will enables you to store your smart contracts and wrap the client into an Arc type for thread safety.

Compile and Deploy Contract Script

This example function will compile and deploy the Incrementer.sol smart contract you created in the previous section. The Incrementer.sol smart contract should be in the root directory. In the main.rs file, you can take the following steps:

Create a new asynchronous function named compile_deploy_contract that takes a client object's reference as input, and returns an address in the form of H160
Define a variable named source as the path for the directory that hosts all of the smart contracts that should be compiled, which is the root directory
Use the Solc crate to compile all of the smart contracts in the root directory
Get the ABI and bytecode from the compiled result, searching for the Incrementer.sol contract
Create a contract factory for the smart contract using the ABI, bytecode, and client. The client must be wrapped into an Arc type for thread safety
Use the factory to deploy. For this example, the value 5 is used as the initial value in the constructor
Print out the address after the deployment
Return the address
Call the compile_deploy_contract function in main

// ...

// 1. Define an asynchronous function that takes a client provider as input and returns H160
async fn compile_deploy_contract(client: &Client) -> Result<H160, Box<dyn std::error::Error>> {
    // 2. Define a path as the directory that hosts the smart contracts in the project
    let source = Path::new(&env!("CARGO_MANIFEST_DIR"));

    // 3. Compile all of the smart contracts
    let compiled = Solc::default()
        .compile_source(source)
        .expect("Could not compile contracts");

    // 4. Get ABI & Bytecode for Incrementer.sol
    let (abi, bytecode, _runtime_bytecode) = compiled
        .find("Incrementer")
        .expect("could not find contract")
        .into_parts_or_default();

    // 5. Create a contract factory which will be used to deploy instances of the contract
    let factory = ContractFactory::new(abi, bytecode, Arc::new(client.clone()));

    // 6. Deploy
    let contract = factory.deploy(U256::from(5))?.send().await?;

    // 7. Print out the address
    let addr = contract.address();
    println!("Incrementer.sol has been deployed to {:?}", addr);

    // 8. Return the address
    Ok(addr)
}

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    // ...

    // 9. Call compile_deploy_contract function in main
    let addr = compile_deploy_contract(&client).await?;

    Ok(())
}

Read Contract Data (Call Methods)

Rust is typesafe, which is why the ABI for the Incrementer.sol contract is required to generate a typesafe Rust struct. For this example, you should create a new file in the root of the Cargo project called Incrementer_ABI.json:

touch Incrementer_ABI.json

The ABI for Incrementer.sol is below, which should be copied and pasted into the Incrementer_ABI.json file:

[
    {
        "inputs": [
            {
                "internalType": "uint256",
                "name": "_value",
                "type": "uint256"
            }
        ],
        "name": "increment",
        "outputs": [],
        "stateMutability": "nonpayable",
        "type": "function"
    },
    {
        "inputs": [],
        "name": "number",
        "outputs": [
            {
                "internalType": "uint256",
                "name": "",
                "type": "uint256"
            }
        ],
        "stateMutability": "view",
        "type": "function"
    },
    {
        "inputs": [],
        "name": "reset",
        "outputs": [],
        "stateMutability": "nonpayable",
        "type": "function"
    }
]

Then you can take the following steps to create a function that reads and returns the number method of the Incrementer.sol contract:

Generate a type-safe interface for the Incrementer smart contract with the abigen macro
Create a new asynchronous function named read_number that takes a client object's reference and a contract address reference as input, and returns a U256
Create a new instance of the Incrementer object generated by the abigen macro with the client and contract address values
Call the number function in the new Incrementer object
Print out the resultant value
Return the resultant value
Call the read_number function in main

// ...

// 1. Generate a type-safe interface for the Incrementer smart contract
abigen!(
    Incrementer,
    "./Incrementer_ABI.json",
    event_derives(serde::Deserialize, serde::Serialize)
);

// 2. Define an asynchronous function that takes a client provider and address as input and returns a U256
async fn read_number(client: &Client, contract_addr: &H160) -> Result<U256, Box<dyn std::error::Error>> {
    // 3. Create contract instance
    let contract = Incrementer::new(contract_addr.clone(), Arc::new(client.clone()));

    // 4. Call contract's number function
    let value = contract.number().call().await?;

    // 5. Print out number
    println!("Incrementer's number is {}", value);

    // 6. Return the number
    Ok(value)
}

// ...

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    // ...

    // 7. Call read_number function in main
    read_number(&client, &addr).await?;

    Ok(())
}

View the complete script

use ethers::providers::{Provider, Http};
use ethers::{prelude::*};
use ethers_solc::Solc;
use std::{path::Path, sync::Arc};

type Client = SignerMiddleware<Provider<Http>, Wallet<k256::ecdsa::SigningKey>>;

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let provider: Provider<Http> = Provider::<Http>::try_from("https://testnet.phron.ai")?; // Change to correct network
    // Do not include the private key in plain text in any production code. This is just for demonstration purposes
    // Do not include '0x' at the start of the private key
    let wallet: LocalWallet = "INSERT_PRIVATE_KEY"
        .parse::<LocalWallet>()?
        .with_chain_id(Chain::Phron);
    let client = SignerMiddleware::new(provider.clone(), wallet.clone());

    // Deploy contract and read initial incrementer value
    let addr = compile_deploy_contract(&client).await?;
    read_number(&client, &addr).await?;

    // Increment and read the incremented number
    increment_number(&client, &addr).await?;
    read_number(&client, &addr).await?;

    // Reset the incremented number and read it
    reset(&client, &addr).await?;
    read_number(&client, &addr).await?;

    Ok(())
}

// Need to install solc for this tutorial: https://github.com/crytic/solc-select
async fn compile_deploy_contract(client: &Client) -> Result<H160, Box<dyn std::error::Error>> {
    // Incrementer.sol is located in the root directory
    let source = Path::new(&env!("INSERT_CARGO_MANIFEST_DIR"));

    // Compile it
    let compiled = Solc::default()
        .compile_source(source)
        .expect("Could not compile contracts");

    // Get ABI & Bytecode for Incrementer.sol
    let (abi, bytecode, _runtime_bytecode) = compiled
        .find("Incrementer")
        .expect("could not find contract")
        .into_parts_or_default();

    // Create a contract factory which will be used to deploy instances of the contract
    let factory = ContractFactory::new(abi, bytecode, Arc::new(client.clone()));

    // Deploy
    let contract = factory.deploy(U256::from(5))?.send().await?;
    let addr = contract.address();

    println!("Incrementer.sol has been deployed to {:?}", addr);

    Ok(addr)
}

// Generates a type-safe interface for the Incrementer smart contract
abigen!(
    Incrementer,
    "./Incrementer_ABI.json",
    event_derives(serde::Deserialize, serde::Serialize)
);

async fn read_number(client: &Client, contract_addr: &H160) -> Result<U256, Box<dyn std::error::Error>> {
    // Create contract instance
    let contract = Incrementer::new(contract_addr.clone(), Arc::new(client.clone()));

    // Call contract's number function
    let value = contract.number().call().await?;

    // Print out value
    println!("Incrementer's number is {}", value);

    Ok(value)
}

async fn increment_number(client: &Client, contract_addr: &H160) -> Result<(), Box<dyn std::error::Error>> {
    println!("Incrementing number...");

    // Create contract instance
    let contract = Incrementer::new(contract_addr.clone(), Arc::new(client.clone()));

    // Send contract transaction
    let tx = contract.increment(U256::from(5)).send().await?.await?;
    println!("Transaction Receipt: {}", serde_json::to_string(&tx)?);

    Ok(())
}

async fn reset(client: &Client, contract_addr: &H160) -> Result<(), Box<dyn std::error::Error>> {
    println!("Resetting number...");

    // Create contract instance
    let contract = Incrementer::new(contract_addr.clone(), Arc::new(client.clone()));

    // Send contract transaction
    let tx = contract.reset().send().await?.await?;
    println!("Transaction Receipt: {}", serde_json::to_string(&tx)?);

    Ok(())
}

To run the script, which will deploy the contract and return the current value stored in the Incrementer contract, you can enter the following command into your terminal:

cargo run

If successful, you'll see the deployed contract's address and initial value set, which should be 5, displayed in the terminal.

cargo runCompiling ethers-examples v0.1.0 (/Users/phron/workspace/ethers-examples)Finished dev [unoptimized + debuginfo] target(s) in 1.09sRunning `/Users/phron/workspace/ethers-examples/target/debug/ethers-examples`Incrementer.sol has been deployed to 0xeb8a4d5c7cd56c65c9dbd25f793b50a2c917bb5dIncrementer's number is 5

Interact with Contract (Send Methods)

Send methods are the type of interaction that modify the contract's storage (change variables), meaning a transaction needs to be signed and sent. In this section, you'll create two functions: one to increment and one to reset the incrementer. This section will also require the Incrementer_ABI.json file initialized when reading from the smart contract.

Take the following steps to create the function to increment:

Ensure that the abigen macro is called for the Incrementer_ABI.json somewhere in the main.rs file (if it is already in the main.rs file, you do not have to have a second one)
Create a new asynchronous function named increment_number that takes a client object's reference and an address as input
Create a new instance of the Incrementer object generated by the abigen macro with the client and contract address values
Call the increment function in the new Incrementer object by including a U256 object as input. In this instance, the value provided is 5
Call the read_number function in main

// ...

// 1. Generate a type-safe interface for the Incrementer smart contract
abigen!(
    Incrementer,
    "./Incrementer_ABI.json",
    event_derives(serde::Deserialize, serde::Serialize)
);

// 2. Define an asynchronous function that takes a client provider and address as input
async fn increment_number(client: &Client, contract_addr: &H160) -> Result<(), Box<dyn std::error::Error>> {
    println!("Incrementing number...");

    // 3. Create contract instance
    let contract = Incrementer::new(contract_addr.clone(), Arc::new(client.clone()));

    // 4. Send contract transaction
    let tx = contract.increment(U256::from(5)).send().await?.await?;
    println!("Transaction Receipt: {}", serde_json::to_string(&tx)?);

    Ok(())
}

// ...

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    // ...

    // 5. Call increment_number function in main
    increment_number(&client, &addr).await?;

    Ok(())
}

View the complete script

use ethers::providers::{Provider, Http};
use ethers::{prelude::*};
use ethers_solc::Solc;
use std::{path::Path, sync::Arc};

type Client = SignerMiddleware<Provider<Http>, Wallet<k256::ecdsa::SigningKey>>;

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let provider: Provider<Http> = Provider::<Http>::try_from("https://testnet.phron.ai")?; // Change to correct network
    // Do not include the private key in plain text in any production code. This is just for demonstration purposes
    // Do not include '0x' at the start of the private key
    let wallet: LocalWallet = "INSERT_PRIVATE_KEY"
        .parse::<LocalWallet>()?
        .with_chain_id(Chain::Phron);
    let client = SignerMiddleware::new(provider.clone(), wallet.clone());

    // Deploy contract and read initial incrementer value
    let addr = compile_deploy_contract(&client).await?;
    read_number(&client, &addr).await?;

    // Increment and read the incremented number
    increment_number(&client, &addr).await?;
    read_number(&client, &addr).await?;

    // Reset the incremented number and read it
    reset(&client, &addr).await?;
    read_number(&client, &addr).await?;

    Ok(())
}

// Need to install solc for this tutorial: https://github.com/crytic/solc-select
async fn compile_deploy_contract(client: &Client) -> Result<H160, Box<dyn std::error::Error>> {
    // Incrementer.sol is located in the root directory
    let source = Path::new(&env!("INSERT_CARGO_MANIFEST_DIR"));

    // Compile it
    let compiled = Solc::default()
        .compile_source(source)
        .expect("Could not compile contracts");

    // Get ABI & Bytecode for Incrementer.sol
    let (abi, bytecode, _runtime_bytecode) = compiled
        .find("Incrementer")
        .expect("could not find contract")
        .into_parts_or_default();

    // Create a contract factory which will be used to deploy instances of the contract
    let factory = ContractFactory::new(abi, bytecode, Arc::new(client.clone()));

    // Deploy
    let contract = factory.deploy(U256::from(5))?.send().await?;
    let addr = contract.address();

    println!("Incrementer.sol has been deployed to {:?}", addr);

    Ok(addr)
}

// Generates a type-safe interface for the Incrementer smart contract
abigen!(
    Incrementer,
    "./Incrementer_ABI.json",
    event_derives(serde::Deserialize, serde::Serialize)
);

async fn read_number(client: &Client, contract_addr: &H160) -> Result<U256, Box<dyn std::error::Error>> {
    // Create contract instance
    let contract = Incrementer::new(contract_addr.clone(), Arc::new(client.clone()));

    // Call contract's number function
    let value = contract.number().call().await?;

    // Print out value
    println!("Incrementer's number is {}", value);

    Ok(value)
}

async fn increment_number(client: &Client, contract_addr: &H160) -> Result<(), Box<dyn std::error::Error>> {
    println!("Incrementing number...");

    // Create contract instance
    let contract = Incrementer::new(contract_addr.clone(), Arc::new(client.clone()));

    // Send contract transaction
    let tx = contract.increment(U256::from(5)).send().await?.await?;
    println!("Transaction Receipt: {}", serde_json::to_string(&tx)?);

    Ok(())
}

async fn reset(client: &Client, contract_addr: &H160) -> Result<(), Box<dyn std::error::Error>> {
    println!("Resetting number...");

    // Create contract instance
    let contract = Incrementer::new(contract_addr.clone(), Arc::new(client.clone()));

    // Send contract transaction
    let tx = contract.reset().send().await?.await?;
    println!("Transaction Receipt: {}", serde_json::to_string(&tx)?);

    Ok(())
}

To run the script, you can enter the following command into your terminal:

cargo run

If successful, the transaction receipt will be displayed in the terminal. You can use the read_number function in the main function to make sure that value is changing as expected. If you're using the read_number function after incrementing, you'll also see the incremented number, which should be 10.

cargo runCompiling ethers-examples v0.1.0 (/Users/phron/workspace/ethers-examples)Finished dev [unoptimized + debuginfo] target(s) in 1.09sRunning `/Users/phron/workspace/ethers-examples/target/debug/ethers-examples`Incrementer.sol has been deployed to 0xeb8a4d5c7cd56c65c9dbd25f793b50a2c917bb5dIncrementer's number is 5Incrementing number...Transaction Receipt: {"transactionHash":"0x6f5c204e74b96b6cf6057512ba142ad727718646d4ebb7abe8bbabada198dafb","transactionIndex":"0x0","blockHash":"0x635a8a234b30c6ee907198ddda3a1478ae52c6adbcc4a67353dd9597ee626950","blockNumber":"0x7ac238","from":"0x3b939fead1557c741ff06492fd0127bd287a421e","to":"0xeb8a4d5c7cd56c65c9dbd25f793b50a2c917bb5d","cumulativeGasUsed":"0x68a6","gasUsed":"0x68a6","contractAddress":null,"logs":[],"status":"0x1","logsBloom":"0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000","type":"0x2","effectiveGasPrice":"0xba43b740"}Incrementer's number is 10

Next you can interact with the reset function:

Ensure that the abigen macro is called for the Incrementer_ABI.json somewhere in the main.rs file (if it is already in the main.rs file, you do not have to have a second one)
Create a new asynchronous function named reset that takes a client object's reference and an address as input
Create a new instance of the Incrementer object generated by the abigen macro with the client and contract address values
Call the reset function in the new Incrementer object
Call the reset function in main

// ...

// 1. Generate a type-safe interface for the Incrementer smart contract
abigen!(
    Incrementer,
    "./Incrementer_ABI.json",
    event_derives(serde::Deserialize, serde::Serialize)
);

// 2. Define an asynchronous function that takes a client provider and address as input
async fn reset(client: &Client, contract_addr: &H160) -> Result<(), Box<dyn std::error::Error>> {
    println!("Resetting number...");

    // 3. Create contract instance
    let contract = Incrementer::new(contract_addr.clone(), Arc::new(client.clone()));

    // 4. Send contract transaction
    let tx = contract.reset().send().await?.await?;
    println!("Transaction Receipt: {}", serde_json::to_string(&tx)?);

    Ok(())
}

// ...

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    // ...

    // 5. Call reset function in main
    reset(&client, &addr).await?;

    Ok(())
}

If successful, the transaction receipt will be displayed in the terminal. You can use the read_number function in the main function to make sure that value is changing as expected. If you're using the read_number function after resetting the number, you should see 0 printed to the terminal.

cargo runCompiling ethers-examples v0.1.0 (/Users/phron/workspace/ethers-examples)Finished dev [unoptimized + debuginfo] target(s) in 1.09sRunning `/Users/phron/workspace/ethers-examples/target/debug/ethers-examples`Incrementer.sol has been deployed to 0xeb8a4d5c7cd56c65c9dbd25f793b50a2c917bb5dIncrementer's number is 5Incrementing number...Transaction Receipt: {"transactionHash":"0x6f5c204e74b96b6cf6057512ba142ad727718646d4ebb7abe8bbabada198dafb","transactionIndex":"0x0","blockHash":"0x635a8a234b30c6ee907198ddda3a1478ae52c6adbcc4a67353dd9597ee626950","blockNumber":"0x7ac238","from":"0x3b939fead1557c741ff06492fd0127bd287a421e","to":"0xeb8a4d5c7cd56c65c9dbd25f793b50a2c917bb5d","cumulativeGasUsed":"0x68a6","gasUsed":"0x68a6","contractAddress":null,"logs":[],"status":"0x1","logsBloom":"0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000","type":"0x2","effectiveGasPrice":"0xba43b740"}Incrementer's number is 10Resetting number...Transaction Receipt: {"transactionHash":"0xf1010597c6ab3d3cfcd6e8e68bf2eddf4ed38eb93a3052591c88b675ed1e83a4","transactionIndex":"0x0","blockHash":"0x5d4c09abf104cbd88e80487c170d8709aae7475ca84c1f3396f3e35222fbe87f","blockNumber":"0x7ac23b","from":"0x3b939fead1557c741ff06492fd0127bd287a421e","to":"0xeb8a4d5c7cd56c65c9dbd25f793b50a2c917bb5d","cumulativeGasUsed":"0x53c4","gasUsed":"0x53c4","contractAddress":null,"logs":[],"status":"0x1","logsBloom":"0x000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000","type":"0x2","effectiveGasPrice":"0xba43b740"}Incrementer's number is 0

View the complete script

use ethers::providers::{Provider, Http};
use ethers::{prelude::*};
use ethers_solc::Solc;
use std::{path::Path, sync::Arc};

type Client = SignerMiddleware<Provider<Http>, Wallet<k256::ecdsa::SigningKey>>;

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let provider: Provider<Http> = Provider::<Http>::try_from("https://testnet.phron.ai")?; // Change to correct network
    // Do not include the private key in plain text in any production code. This is just for demonstration purposes
    // Do not include '0x' at the start of the private key
    let wallet: LocalWallet = "INSERT_PRIVATE_KEY"
        .parse::<LocalWallet>()?
        .with_chain_id(Chain::Phron);
    let client = SignerMiddleware::new(provider.clone(), wallet.clone());

    // Deploy contract and read initial incrementer value
    let addr = compile_deploy_contract(&client).await?;
    read_number(&client, &addr).await?;

    // Increment and read the incremented number
    increment_number(&client, &addr).await?;
    read_number(&client, &addr).await?;

    // Reset the incremented number and read it
    reset(&client, &addr).await?;
    read_number(&client, &addr).await?;

    Ok(())
}

// Need to install solc for this tutorial: https://github.com/crytic/solc-select
async fn compile_deploy_contract(client: &Client) -> Result<H160, Box<dyn std::error::Error>> {
    // Incrementer.sol is located in the root directory
    let source = Path::new(&env!("INSERT_CARGO_MANIFEST_DIR"));

    // Compile it
    let compiled = Solc::default()
        .compile_source(source)
        .expect("Could not compile contracts");

    // Get ABI & Bytecode for Incrementer.sol
    let (abi, bytecode, _runtime_bytecode) = compiled
        .find("Incrementer")
        .expect("could not find contract")
        .into_parts_or_default();

    // Create a contract factory which will be used to deploy instances of the contract
    let factory = ContractFactory::new(abi, bytecode, Arc::new(client.clone()));

    // Deploy
    let contract = factory.deploy(U256::from(5))?.send().await?;
    let addr = contract.address();

    println!("Incrementer.sol has been deployed to {:?}", addr);

    Ok(addr)
}

// Generates a type-safe interface for the Incrementer smart contract
abigen!(
    Incrementer,
    "./Incrementer_ABI.json",
    event_derives(serde::Deserialize, serde::Serialize)
);

async fn read_number(client: &Client, contract_addr: &H160) -> Result<U256, Box<dyn std::error::Error>> {
    // Create contract instance
    let contract = Incrementer::new(contract_addr.clone(), Arc::new(client.clone()));

    // Call contract's number function
    let value = contract.number().call().await?;

    // Print out value
    println!("Incrementer's number is {}", value);

    Ok(value)
}

async fn increment_number(client: &Client, contract_addr: &H160) -> Result<(), Box<dyn std::error::Error>> {
    println!("Incrementing number...");

    // Create contract instance
    let contract = Incrementer::new(contract_addr.clone(), Arc::new(client.clone()));

    // Send contract transaction
    let tx = contract.increment(U256::from(5)).send().await?.await?;
    println!("Transaction Receipt: {}", serde_json::to_string(&tx)?);

    Ok(())
}

async fn reset(client: &Client, contract_addr: &H160) -> Result<(), Box<dyn std::error::Error>> {
    println!("Resetting number...");

    // Create contract instance
    let contract = Incrementer::new(contract_addr.clone(), Arc::new(client.clone()));

    // Send contract transaction
    let tx = contract.reset().send().await?.await?;
    println!("Transaction Receipt: {}", serde_json::to_string(&tx)?);

    Ok(())
}

viem

viem TypeScript Ethereum Library

Introduction

viem is a modular TypeScript library that allows developers to interact with abstractions over the JSON-RPC API, making it easy to interact with Ethereum nodes. Since Phron has an Ethereum-like API available that is fully compatible with Ethereum-style JSON RPC invocations, developers can leverage this compatibility to interact with Phron nodes. For more information on viem, check out their documentation site.

In this guide, you'll learn how to use viem to send a transaction and deploy a contract on the Phron TestNet.

Checking Prerequisites

For the examples in this guide, you will need to have the following:

An account with funds. You can get DEV tokens for testing on Phron once every 24 hours from the Phron Faucet
To test out the examples in this guide on Phron, you will need to have your own endpoint and API key, which you can get from one of the supported Endpoint Providers

Note
The examples in this guide assume you have a MacOS or Ubuntu 22.04-based environment and will need to be adapted accordingly for Windows.

Installing viem

To get started, you'll need to create a basic TypeScript project. First, create a directory to store all of the files you'll be creating throughout this guide, and initialize the project with the following command:

mkdir viem-examples && cd viem-examples && npm init --y

For this guide, you'll need to install the viem library and the Solidity compiler. To install both packages, you can run the following command:

npm install typescript ts-node viem solc@0.8.0

You can create a TypeScript configuration file by running:

npx tsc --init

Note
This tutorial was created using Node.js v18.18.0.

Set Up a viem Client (Provider)

Throughout this guide, you'll be creating a bunch of scripts that provide different functionality, such as sending a transaction, deploying a contract, and interacting with a deployed contract. In most of these scripts, you'll need to create a viem client to interact with the network.

You can create a viem client for reading chain data, like balances or contract data, using the createPublicClient function, or you can create a viem client for writing chain data, like sending transactions, using the createWalletClient function.

For Reading Chain Data

To create a client for reading chain data, you can take the following steps:

Import the createPublicClient and http functions from viem and the network you want to interact with from viem/chains. The chain can be any of the following: phron
Create the client using the createPublicClient function and pass in the network and the HTTP RPC endpoint

import { createPublicClient, http } from 'viem';
import { phron } from 'viem/chains';

const rpcUrl = 'INSERT_RPC_API_ENDPOINT'
const publicClient = createPublicClient({
  chain: phron,
  transport: http(rpcUrl),
});

For Writing Chain Data

To create a client for writing chain data, you can take the following steps:

Import the createWalletClient and http functions from viem, the privateKeyToAccount function for loading your accounts via their private keys, and the network you want to interact with from viem/chains. The chain can be any of the following: phron
Create your account using the privateKeyToAccount function
Create the client using the createWalletClient function and pass in the account, network, and the HTTP RPC endpoint

Remember

This is for demo purposes only. Never store your private key in a TypeScript file.

import { createWalletClient, http } from 'viem';
import { privateKeyToAccount } from 'viem/accounts';
import { phron } from 'viem/chains';

const account = privateKeyToAccount('INSERT_PRIVATE_KEY');
const rpcUrl = 'INSERT_RPC_API_ENDPOINT'
const walletClient = createWalletClient({
  account,
  chain: phron,
  transport: http(rpcUrl),
});

Note
To interact with browser-based wallets, you can use the following code to create an account:
const [account] = await window.ethereum.request({
  method: 'eth_requestAccounts',
});
const walletClient = createWalletClient({
  account,
  chain: phron,
  transport: custom(window.ethereum),
});

const [account] = await window.ethereum.request({
  method: 'eth_requestAccounts',
});
const walletClient = createWalletClient({
  account,
  chain: phron,
  transport: custom(window.ethereum),
});

Send a Transaction

You can also use the balance script to check the account balances after the transaction has been sent.

Check Balances Script

You'll only need one file to check the balances of both addresses before and after the transaction is sent. To get started, you can create a balances.ts file by running:

touch balances.ts

Next, you will create the script for this file and complete the following steps:

Update your imports to include the createPublicClient, http, and formatEther functions from viem and the network you want to interact with from viem/chains
Set up a public viem client, which can be used for reading chain data, such as account balances
Define the addressFrom and addressTo variables
Create the asynchronous balances function that wraps the publicClient.getBalance method
Use the publicClient.getBalance function to fetch the balances for the addressFrom and addressTo addresses. You can also leverage the formatEther function to transform the balance into a more readable number (in GLMR, MOVR, or DEV)
Lastly, run the balances function

// 1. Imports
import { createPublicClient, http, formatEther } from 'viem';
import { phron } from 'viem/chains';

// 2. Create a public client for reading chain data
const rpcUrl = 'https://testnet.phron.ai';
const publicClient = createPublicClient({
  chain: phron,
  transport: http(rpcUrl),
});

// 3. Create address variables
const addressFrom = 'INSERT_FROM_ADDRESS';
const addressTo = 'INSERT_TO_ADDRESS';

// 4. Create balances function
const balances = async () => {
  // 5. Fetch balances
  const balanceFrom = formatEther(
    await publicClient.getBalance({ address: addressFrom })
  );
  const balanceTo = formatEther(
    await publicClient.getBalance({ address: addressTo })
  );

  console.log(`The balance of ${addressFrom} is: ${balanceFrom} DEV`);
  console.log(`The balance of ${addressTo} is: ${balanceTo} DEV`);
};

// 6. Call the balances function
balances();

To run the script and fetch the account balances, you can run the following command:

npx ts-node balances.ts

If successful, the balances for the origin and receiving address will be displayed in your terminal in DEV.

npx ts-node balances.tsThe balance of 0x3B939FeaD1557C741Ff06492FD0127bd287A421e is: 3601.72 DEVThe balance of 0x78F34038c82638E0563b974246D421154C26b004 is: 0 DEV

Send Transaction Script

You'll only need one file to execute a transaction between accounts. For this example, you'll be transferring 1 DEV token from an origin address (from which you hold the private key) to another address. To get started, you can create a transaction.ts file by running:

touch transaction.ts

Next, you will create the script for this file and complete the following steps:

Update your imports to include the createWalletClient, http, and parseEther functions from viem, the privateKeyToAccount function from viem/accounts, and the network you want to interact with from viem/chains
Set up a viem wallet client for writing chain data, which can be used along with your private key to send transactions. Note: This is for example purposes only. Never store your private keys in a TypeScript file
Set up a public viem client for reading chain data, which will be used to wait for the transaction receipt
Define the addressTo variable
Create the asynchronous send function, which wraps the transaction object and the walletClient.sendTransaction method
Use the walletClient.sendTransaction function to sign and send the transaction. You'll need to pass in the transaction object, which only requires the recipient's address and the amount to send. Note that parseEther can be used, which handles the necessary unit conversions from Ether to Wei, similar to using parseUnits(value, decimals). Use await to wait until the transaction is processed and the transaction hash is returned
Use the publicClient.waitForTransactionReceipt function to wait for the transaction receipt, signaling that the transaction has been completed. This is particularly helpful if you need the transaction receipt or if you're running the balances.ts script directly after this one to check if the balances have been updated as expected
Lastly, run the send function

// 1. Imports
import { createPublicClient, createWalletClient, http, parseEther } from 'viem';
import { privateKeyToAccount } from 'viem/accounts';
import { phron } from 'viem/chains';

// 2. Create a wallet client for writing chain data
const account = privateKeyToAccount('INSERT_PRIVATE_KEY');
const rpcUrl = 'https://testnet.phron.ai';
const walletClient = createWalletClient({
  account,
  chain: phron,
  transport: http(rpcUrl),
});

// 3. Create a public client for reading chain data
const publicClient = createPublicClient({
  chain: phron,
  transport: http(rpcUrl),
});

// 4. Create to address variable
const addressTo = 'INSERT_ADDRESS';

// 5. Create send function
const send = async () => {
  console.log(
    `Attempting to send transaction from ${account.address} to ${addressTo}`
  );

  // 6. Sign and send tx
  const hash = await walletClient.sendTransaction({
    to: addressTo,
    value: parseEther('1'),
  });

  // 7. Wait for the transaction receipt
  await publicClient.waitForTransactionReceipt({
    hash,
  });

  console.log(`Transaction successful with hash: ${hash}`);
};

// 8. Call the send function
send();

To run the script, you can run the following command in your terminal:

npx ts-node transaction.ts

If the transaction was successful, in your terminal you'll see the transaction hash has been printed out.

Note
Viem requires that you prepend your private key with 0x. Many wallets omit this 0x, so verify you've included it as you replace INSERT_PRIVATE_KEY.

You can also use the balances.ts script to check that the balances for the origin and receiving accounts have changed. The entire workflow would look like this:

npx ts-node balances.tsThe balance of 0x3B939FeaD1557C741Ff06492FD0127bd287A421e is: 3601.72 DEVThe balance of 0x78F34038c82638E0563b974246D421154C26b004 is: 0 DEV
npx ts-node transaction.ts Attempting to send transaction from 0x3B939FeaD1557C741Ff06492FD0127bd287A421e to 0x78F34038c82638E0563b974246D421154C26b004 Transaction successful with hash: 0xc482d907b2ae4ca1202c6cc5b486694b8439a9853caad9c2cdafec39defa1968 npx ts-node balances.ts The balance of 0x3B939FeaD1557C741Ff06492FD0127bd287A421e is: 3600.72 DEV The balance of 0x78F34038c82638E0563b974246D421154C26b004 is: 1 DEV

Deploy a Contract

touch Incrementer.sol

Next, you can add the Solidity code to the file:

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

contract Incrementer {
    uint256 public number;

    constructor(uint256 _initialNumber) {
        number = _initialNumber;
    }

    function increment(uint256 _value) public {
        number = number + _value;
    }

    function reset() public {
        number = 0;
    }
}

Note
This contract is a simple example for illustration purposes only and does not handle values wrapping around.

Compile Contract Script

touch compile.ts

Next, you will create the script for this file and complete the following steps:

Import the fs and solc packages
Using the fs.readFileSync function, you'll read and save the file contents of Incrementer.sol to source
Build the input object for the Solidity compiler by specifying the language, sources, and settings to be used
Using the input object, you can compile the contract using solc.compile
Extract the compiled contract file and export it to be used in the deployment script

// 1. Import packages
const fs = require('fs');
const solc = require('solc');

// 2. Get path and load contract
const source = fs.readFileSync('Incrementer.sol', 'utf8');

// 3. Create input object
const input = {
   language: 'Solidity',
   sources: {
      'Incrementer.sol': {
         content: source,
      },
   },
   settings: {
      outputSelection: {
         '*': {
            '*': ['*'],
         },
      },
   },
};
// 4. Compile the contract
const tempFile = JSON.parse(solc.compile(JSON.stringify(input)));
const contractFile = tempFile.contracts['Incrementer.sol']['Incrementer'];

// 5. Export contract data
export default contractFile;

Deploy Contract Script

touch deploy.ts

Next, you will create the script for this file and complete the following steps:

Update your imports to include the createPublicClient, createWalletClient, and http functions from viem, the privateKeyToAccount function from viem/accounts, the network you want to interact with from viem/chains, and the contractFile from the compile.ts file you created in the Compile Contract Script section
Set up a viem wallet client for writing chain data, which will be used along with your private key to deploy the Incrementer contract. Note: This is for example purposes only. Never store your private keys in a TypeScript file
Set up a public viem client for reading chain data, which will be used to read the transaction receipt for the deployment
Load the contract bytecode and abi for the compiled contract
Create the asynchronous deploy function that will be used to deploy the contract via the walletClient.deployContract method
Use the walletClient.deployContract function to sign and send the transaction. You'll need to pass in the contract's ABI and bytecode, the account to deploy the transaction from, and the initial value for the incrementer. Use await to wait until the transaction is processed and the transaction hash is returned
Use the publicClient.readContract function to get the transaction receipt for the deployment. Use await to wait until the transaction is processed and the contract address is returned
Lastly, run the deploy function

// 1. Update imports
import { createPublicClient, createWalletClient, http } from 'viem';
import { privateKeyToAccount } from 'viem/accounts';
import { phron } from 'viem/chains';
import contractFile from './compile';

// 2. Create a wallet client for writing chain data
// The private key must be prepended with `0x` to avoid errors
const account = privateKeyToAccount('INSERT_PRIVATE_KEY');
const rpcUrl = 'https://testnet.phron.ai';
const walletClient = createWalletClient({
  account,
  chain: phron,
  transport: http(rpcUrl),
});
// 3. Create a public client for reading chain data
const publicClient = createPublicClient({
  chain: phron,
  transport: http(rpcUrl),
});

// 4. Load contract information
const bytecode = contractFile.evm.bytecode.object;
const abi = contractFile.abi;
const _initialNumber = 5;

// 5. Create deploy function
const deploy = async () => {
  console.log(`Attempting to deploy from account: ${account.address}`);

  // 6. Send tx (initial value set to 5)
  const contract = await walletClient.deployContract({
    abi,
    account,
    bytecode,
    args: [_initialNumber],
  });

  // 7. Get the transaction receipt for the deployment
  const transaction = await publicClient.waitForTransactionReceipt({
    hash: contract,
  });

  console.log(`Contract deployed at address: ${transaction.contractAddress}`);
};

// 8. Call the deploy function
deploy();

To run the script, you can enter the following command into your terminal:

npx ts-node deploy.ts

If successful, the contract's address will be displayed in the terminal.

npx ts-node deploy.tsAttempting to deploy from account: 0x3B939FeaD1557C741Ff06492FD0127bd287A421eContract deployed at address: 0x4503b1086c6780e888194fd9caebca5f65b210c9

Read Contract Data (Call Methods)

Call methods are the type of interaction that doesn't modify the contract's storage (change variables), meaning no transaction needs to be sent. They simply read various storage variables of the deployed contract.

To get started, you can create a file and name it get.ts:

touch get.ts

Then you can take the following steps to create the script:

Update your imports to include the createPublicClient and http functions from viem, the network you want to interact with from viem/chains, and the contractFile from the compile.ts file you created in the Compile Contract Script section
Set up a public viem client for reading chain data, which will be used to read the current number of the Incrementer contract
Create the contractAddress variable using the address of the deployed contract and the abi variable using the contractFile from the compile.ts file
Create the asynchronous get function
Call the contract using the publicClient.readContract function, passing in the abi, the name of the function, the contractAddress, and any arguments (if needed). You can use await, which will return the value requested once the request promise resolves
Lastly, call the get function

// 1. Update imports
import { createPublicClient, http } from 'viem';
import { phron } from 'viem/chains';
import contractFile from './compile';

// 2. Create a public client for reading chain data
const rpcUrl = 'https://testnet.phron.ai';
const client = createPublicClient({
  chain: phron,
  transport: http(rpcUrl),
});

// 3. Create contract variables
const contractAddress = 'INSERT_CONTRACT_ADDRESS';
const abi = contractFile.abi;

// 4. Create get function
const get = async () => {
  console.log(`Making a call to contract at address: ${contractAddress}`);

  // 5. Call contract
  const data = await client.readContract({
    abi,
    functionName: 'number',
    address: contractAddress,
    args: [],
  });

  console.log(`The current number stored is: ${data}`);
};

// 6. Call get function
get();

To run the script, you can enter the following command in your terminal:

npx ts-node get.ts

If successful, the value will be displayed in the terminal.

npx ts-node get.tsMaking a call to contract at address: 0x4503b1086c6780e888194fd9caebca5f65b210c9The current number stored is: 5

Interact with Contract (Send Methods)

Send methods are the type of interactions that modify the contract's storage (change variables), meaning a transaction needs to be signed and sent. In this section, you'll create two scripts: one to increment and one to reset the incrementer. To get started, you can create a file for each script and name them increment.ts and reset.ts:

touch increment.ts reset.ts

Open the increment.ts file and take the following steps to create the script:

Update your imports to include the createWalletClient and http functions from viem, the network you want to interact with from viem/chains, and the contractFile from the compile.ts file you created in the Compile Contract Script section
Set up a viem wallet client for writing chain data, which will be used along with your private key to send a transaction. Note: This is for example purposes only. Never store your private keys in a TypeScript file
Set up a public viem client for reading chain data, which will be used to wait for the transaction receipt
Create the contractAddress variable using the address of the deployed contract, the abi variable using the contractFile from the compile.ts file, and the _value to increment the contract by
Create the asynchronous increment function
Call the contract using the walletClient.writeContract function, passing in the abi, the name of the function, the contractAddress, and the _value. You can use await, which will return the transaction hash once the request promise resolves
Use the publicClient.waitForTransactionReceipt function to wait for the transaction receipt, signaling that the transaction has been completed. This is particularly helpful if you need the transaction receipt or if you're running the get.ts script directly after this one to check that the current number has been updated as expected
Lastly, call the increment function

// 1. Update imports
import { createPublicClient, createWalletClient, http } from 'viem';
import { privateKeyToAccount } from 'viem/accounts';
import { phron } from 'viem/chains';
import contractFile from './compile';

// 2. Create a wallet client for writing chain data
const account = privateKeyToAccount('INSERT_PRIVATE_KEY');
const rpcUrl = 'https://testnet.phron.ai';
const walletClient = createWalletClient({
  account,
  chain: phron,
  transport: http(rpcUrl),
});

// 3. Create a public client for reading chain data
const publicClient = createPublicClient({
  chain: phron,
  transport: http(rpcUrl),
});

// 4. Create contract variables
const contractAddress = 'INSERT_CONTRACT_ADDRESS';
const abi = contractFile.abi;
const _value = 3;

// 5. Create increment function
const increment = async () => {
  console.log(
    `Calling the increment by ${_value} function in contract at address: ${contractAddress}`
  );
  // 6. Call contract
  const hash = await walletClient.writeContract({
    abi,
    functionName: 'increment',
    address: contractAddress,
    args: [_value],
  });

  // 7. Wait for the transaction receipt
  await publicClient.waitForTransactionReceipt({
    hash,
  });

  console.log(`Tx successful with hash: ${hash}`);
};

// 8. Call increment function
increment();

To run the script, you can enter the following command in your terminal:

npx ts-node increment.ts

If successful, the transaction hash will be displayed in the terminal. You can use the get.ts script alongside the increment.ts script to make sure that value is changing as expected.

npx ts-node get.tsMaking a call to contract at address: 0x4503b1086c6780e888194fd9caebca5f65b210c9The current number stored is: 5npx ts-node increment.tsCalling the increment by 3 function in contract at address: 0x4503b1086c6780e888194fd9caebca5f65b210c9Tx successful with hash: 0x041c9767e7a96f60f372341647430560569fd6ff64a27b4b9c6241e55dde57e1npx ts-node get.tsMaking a call to contract at address: 0x4503b1086c6780e888194fd9caebca5f65b210c9The current number stored is: 8

Next, you can open the reset.ts file and take the following steps to create the script:

Update your imports to include the createWalletClient and http functions from viem, the network you want to interact with from viem/chains, and the contractFile from the compile.ts file you created in the Compile Contract Script section
Set up a viem wallet client for writing chain data, which will be used along with your private key to send a transaction. Note: This is for example purposes only. Never store your private keys in a TypeScript file
Set up a public viem client for reading chain data, which will be used to wait for the transaction receipt
Create the contractAddress variable using the address of the deployed contract and the abi variable using the contractFile from the compile.ts file to increment the contract by
Create the asynchronous reset function
Call the contract using the walletClient.writeContract function, passing in the abi, the name of the function, the contractAddress, and an empty array for the arguments. You can use await, which will return the transaction hash once the request promise resolves
Use the publicClient.waitForTransactionReceipt function to wait for the transaction receipt, signaling that the transaction has been completed. This is particularly helpful if you need the transaction receipt or if you're running the get.ts script directly after this one to check that the current number has been reset to 0
Lastly, call the reset function

// 1. Update imports
import { createPublicClient, createWalletClient, http } from 'viem';
import { privateKeyToAccount } from 'viem/accounts';
import { phron } from 'viem/chains';
import contractFile from './compile';

// 2. Create a wallet client for writing chain data
const account = privateKeyToAccount('INSERT_PRIVATE_KEY');
const rpcUrl = 'https://testnet.phron.ai';
const walletClient = createWalletClient({
  account,
  chain: phron,
  transport: http(rpcUrl),
});

// 3. Create a public client for reading chain data
const publicClient = createPublicClient({
  chain: phron,
  transport: http(rpcUrl),
});

// 4. Create contract variables
const contractAddress = 'INSERT_CONTRACT_ADDRESS';
const abi = contractFile.abi;

// 5. Create reset function
const reset = async () => {
  console.log(
    `Calling the reset function in contract at address: ${contractAddress}`
  );

  // 6. Call contract
  const hash = await walletClient.writeContract({
    abi,
    functionName: 'reset',
    address: contractAddress,
    args: [],
  });

  // 7. Wait for the transaction receipt
  await publicClient.waitForTransactionReceipt({
    hash,
  });

  console.log(`Tx successful with hash: ${hash}`);
};

// 8. Call reset function
reset();

To run the script, you can enter the following command in your terminal:

npx ts-node reset.ts

If successful, the transaction hash will be displayed in the terminal. You can use the get.ts script alongside the reset.ts script to make sure that value is changing as expected.

npx ts-node get.tsMaking a call to contract at address: 0x4503b1086c6780e888194fd9caebca5f65b210c9The current number stored is: 8npx ts-node reset.tsCalling the reset function in contract at address: 0x4503b1086c6780e888194fd9caebca5f65b210c9Tx successful with hash: 0xc1a772131ccf6a03675ff3e88798a6e70a99e145eeb0e98170ff2e3345ee14a7npx ts-node get.tsMaking a call to contract at address: 0x4503b1086c6780e888194fd9caebca5f65b210c9The current number stored is: 0

Web3.js

Web3.js JavaScript Library

Introduction

Web3.js is a set of libraries that allow developers to interact with Ethereum nodes using HTTP, IPC, or WebSocket protocols with JavaScript. Phron has an Ethereum-like API available that is fully compatible with Ethereum-style JSON-RPC invocations. Therefore, developers can leverage this compatibility and use the Web3.js library to interact with a Phron node as if they were doing so on Ethereum.

In this guide, you'll learn how to use the Web3.js library to send a transaction and deploy a contract on Phron.

Checking Prerequisites

For the examples in this guide, you will need to have the following:

An account with funds. You can get DEV tokens for testing on Phron once every 24 hours from the Phron Faucet
To test out the examples in this guide on Phron, you will need to have your own endpoint and API key, which you can get from one of the supported Endpoint Providers

Note
The examples in this guide assume you have a MacOS or Ubuntu 22.04-based environment and will need to be adapted accordingly for Windows.

Installing Web3.js

To get started, you'll need to start a basic JavaScript project. First, create a directory to store all of the files you'll be creating throughout this guide, and initialize the project with the following command:

mkdir web3-examples && cd web3-examples && npm init --y

For this guide, you'll need to install the Web3.js library and the Solidity compiler. To install both NPM packages, you can run the following command:

npm install web3 solc@0.8.0

Setup Web3.js with Phron

You can configure Web3.js to work with any of the Phron networks. To configure your project for Phron, you will need to have your own endpoint and API key, which you can get from one of the supported Endpoint Providers.

The simplest way to get started with each of the networks is as follows:

const { Web3 } = require('web3');

// Create Web3 instance
const web3 = new Web3('INSERT_RPC_API_ENDPOINT'); // Insert your RPC URL here

Save this code snippet, as you'll need it for the scripts that are used in the following sections.

Send a Transaction

You can also use the balance script to check the account balances after the transaction has been sent.

Check Balances Script

You'll only need one file to check the balances of both addresses before and after the transaction is sent. To get started, you can create a balances.js file by running:

touch balances.js

Next, you will create the script for this file and complete the following steps:

Set up the Web3 provider
Define the addressFrom and addressTo variables
Create the asynchronous balances function, which wraps the web3.eth.getBalance method
Use the web3.eth.getBalance function to fetch the balances for the addressFrom and addressTo addresses. You can also leverage the web3.utils.fromWei function to transform the balance into a more readable number in DEV
Lastly, run the balances function

// 1. Add the Web3 provider logic
// {...}

// 2. Create address variables
const addressFrom = 'INSERT_FROM_ADDRESS';
const addressTo = 'INSERT_TO_ADDRESS';

// 3. Create balances function
const balances = async () => {
  // 4. Fetch balance info
  const balanceFrom = web3.utils.fromWei(
    await web3.eth.getBalance(addressFrom),
    'ether'
  );
  const balanceTo = web3.utils.fromWei(
    await web3.eth.getBalance(addressTo),
    'ether'
  );

  console.log(`The balance of ${addressFrom} is: ${balanceFrom} DEV`);
  console.log(`The balance of ${addressTo} is: ${balanceTo} DEV`);
};

// 5. Call balances function
balances();

View the complete script

const { Web3 } = require('web3');

// 1. Add the Web3 provider logic here:
const providerRPC = {
  development: 'http://localhost:9944',
  phron: 'https://testnet.phron.ai',
};
const web3 = new Web3(providerRPC.phron); // Change to correct network

// 2. Create address variables
const addressFrom = 'INSERT_FROM_ADDRESS';
const addressTo = 'INSERT_TO_ADDRESS';

// 3. Create balances function
const balances = async () => {
  // 4. Fetch balance info
  const balanceFrom = web3.utils.fromWei(await web3.eth.getBalance(addressFrom), 'ether');
  const balanceTo = web3.utils.fromWei(await web3.eth.getBalance(addressTo), 'ether');

  console.log(`The balance of ${addressFrom} is: ${balanceFrom} DEV`);
  console.log(`The balance of ${addressTo} is: ${balanceTo} DEV`);
};

// 5. Call balances function
balances();

To run the script and fetch the account balances, you can run the following command:

node balances.js

If successful, the balances for the origin and receiving address will be displayed in your terminal in DEV.

Send Transaction Script

touch transaction.js

Next, you will create the script for this file and complete the following steps:

Set up the Web3 provider
Define the accountFrom, including the privateKey, and the addressTo variables. The private key is required to create a wallet instance. Note: This is for example purposes only. Never store your private keys in a JavaScript file
Create the asynchronous send function, which wraps the transaction object, and the sign and send transaction functions
Create and sign the transaction using the web3.eth.accounts.signTransaction function. Pass in the gas, addressTo, value, gasPrice, and nonce for the transaction along with the sender's privateKey
Send the signed transaction using the web3.eth.sendSignedTransaction method and pass in the raw transaction. Then use await to wait until the transaction is processed and the transaction receipt is returned
Lastly, run the send function

// 1. Add the Web3 provider logic
// {...}

// 2. Create account variables
const accountFrom = {
  privateKey: 'INSERT_YOUR_PRIVATE_KEY',
  address: 'INSERT_PUBLIC_ADDRESS_OF_PK',
};
const addressTo = 'INSERT_TO_ADDRESS'; // Change addressTo

// 3. Create send function
const send = async () => {
  console.log(
    `Attempting to send transaction from ${accountFrom.address} to ${addressTo}`
  );

  // 4. Sign transaction with PK
  const createTransaction = await web3.eth.accounts.signTransaction(
    {
      gas: 21000,
      to: addressTo,
      value: web3.utils.toWei('1', 'ether'),
      gasPrice: await web3.eth.getGasPrice(),
      nonce: await web3.eth.getTransactionCount(accountFrom.address),
    },
    accountFrom.privateKey
  );

  // 5. Send transaction and wait for receipt
  const createReceipt = await web3.eth.sendSignedTransaction(
    createTransaction.rawTransaction
  );
  console.log(
    `Transaction successful with hash: ${createReceipt.transactionHash}`
  );
};

// 6. Call send function
send();

View the complete script

const { Web3 } = require('web3');

// 1. Add the Web3 provider logic
const providerRPC = {
  development: 'http://localhost:9944',
  phron: 'https://testnet.phron.ai',
};
const web3 = new Web3(providerRPC.phron); // Change to correct network

// 2. Create account variables
const accountFrom = {
  privateKey: 'INSERT_YOUR_PRIVATE_KEY',
  address: 'INSERT_PUBLIC_ADDRESS_OF_PK',
};
const addressTo = 'INSERT_TO_ADDRESS';

// 3. Create send function
const send = async () => {
  console.log(
    `Attempting to send transaction from ${accountFrom.address} to ${addressTo}`
  );

  // 4. Sign transaction with PK
  const createTransaction = await web3.eth.accounts.signTransaction(
    {
      gas: 21000,
      to: addressTo,
      value: web3.utils.toWei('1', 'ether'),
      gasPrice: await web3.eth.getGasPrice(),
      nonce: await web3.eth.getTransactionCount(accountFrom.address),
    },
    accountFrom.privateKey
  );

  // 5. Send transaction and wait for receipt
  const createReceipt = await web3.eth.sendSignedTransaction(
    createTransaction.rawTransaction
  );
  console.log(
    `Transaction successful with hash: ${createReceipt.transactionHash}`
  );
};

// 6. Call send function
send();

To run the script, you can run the following command in your terminal:

node transaction.js

If the transaction was successful, in your terminal, you'll see the transaction hash has been printed out.

You can also use the balances.js script to check that the balances for the origin and receiving accounts have changed. The entire workflow would look like this:

node balances.jsThe balance of 0x3B939FeaD1557C741Ff06492FD0127bd287A421e is: 3603.67979115380310679 DEVThe balance of 0xe29A0699e079FeBEe94A02f35C31B026f90F6040 is: 0. DEVnode transaction.jsAttempting to send transaction from 0x3B939FeaD1557C741Ff06492FD0127bd287A421e to 0xe29A0699e079FeBEe94A02f35C31B026f90F6040Transaction successful with hash: 0xf1d628ed12c5f40e03e29aa2c23c8c09680ee595c60607c7363a81c0be8ef3cbnode balances.jsThe balance of 0x3B939FeaD1557C741Ff06492FD0127bd287A421e is: 3602.67978852880310679 DEVThe balance of 0xe29A0699e079FeBEe94A02f35C31B026f90F6040 is: 1 DEV

Common Errors When Sending Transactions

When sending a transaction with Web3.js, it is important that you have all of the required data for the transaction. You'll need to provide the from address or the nonce of the sender, the gas or gasLimit, and the gasPrice.

If you do not specify the from address or the nonce of the sender, you may receive the following error:

UnableToPopulateNonceError: Invalid value given "UnableToPopulateNonceError". Error: unable to populate nonce, no from address available.

To fix this, simply add either the from or nonce field to the transaction object.

If you do not specify the gas correctly, you may receive the following error:

MissingGasError: Invalid value given "gas: 0x5208, gasPrice: undefined, maxPriorityFeePerGas: undefined, maxFeePerGas: undefined". Error: "gas" is missing.

To resolve this error, you'll need to make sure that you've provided a gasPrice for the transaction. You can use await web3.eth.getGasPrice() to programmatically get this value.

Deploy a Contract

touch Incrementer.sol

Next, you can add the Solidity code to the file:

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

contract Incrementer {
    uint256 public number;

    constructor(uint256 _initialNumber) {
        number = _initialNumber;
    }

    function increment(uint256 _value) public {
        number = number + _value;
    }

    function reset() public {
        number = 0;
    }
}

Note
This contract is a simple example for illustration purposes only and does not handle values wrapping around.

Compile Contract Script

touch compile.js

Next, you will create the script for this file and complete the following steps:

Import the fs and solc packages
Using the fs.readFileSync function, you'll read and save the file contents of Incrementer.sol to source
Build the input object for the Solidity compiler by specifying the language, sources, and settings to be used
Using the input object, you can compile the contract using solc.compile
Extract the compiled contract file and export it to be used in the deployment script

// 1. Import packages
const fs = require('fs');
const solc = require('solc');

// 2. Get path and load contract
const source = fs.readFileSync('Incrementer.sol', 'utf8');

// 3. Create input object
const input = {
   language: 'Solidity',
   sources: {
      'Incrementer.sol': {
         content: source,
      },
   },
   settings: {
      outputSelection: {
         '*': {
            '*': ['*'],
         },
      },
   },
};
// 4. Compile the contract
const tempFile = JSON.parse(solc.compile(JSON.stringify(input)));
const contractFile = tempFile.contracts['Incrementer.sol']['Incrementer'];

// 5. Export contract data
module.exports = contractFile;

Deploy Contract Script

touch deploy.js

Next, you will create the script for this file and complete the following steps:

Import the contract file from compile.js
Set up the Web3 provider
Define the accountFrom, including the privateKey, and the addressTo variables. The private key is required to create a wallet instance. Note: This is for example purposes only. Never store your private keys in a JavaScript file
Save the bytecode and abi for the compiled contract
Create the asynchronous deploy function that will be used to deploy the contract
Create the contract instance using the web3.eth.Contract function
Create the constructor and pass in the bytecode and the initial value for the incrementer. For this example, you can set the initial value to 5
Create and sign the transaction using the web3.eth.accounts.signTransaction function. Pass in the data, gas, gasPrice, and nonce for the transaction along with the sender's privateKey
Send the signed transaction using the web3.eth.sendSignedTransaction method and pass in the raw transaction. Then use await to wait until the transaction is processed and the transaction receipt is returned
Lastly, run the deploy function

// 1. Import the contract file
const contractFile = require('./compile');

// 2. Add the Web3 provider logic
// {...}

// 3. Create address variables
const accountFrom = {
  privateKey: 'INSERT_YOUR_PRIVATE_KEY',
  address: 'INSERT_PUBLIC_ADDRESS_OF_PK',
};

// 4. Get the bytecode and API
const bytecode = contractFile.evm.bytecode.object;
const abi = contractFile.abi;

// 5. Create deploy function
const deploy = async () => {
  console.log(`Attempting to deploy from account ${accountFrom.address}`);

  // 6. Create contract instance
  const incrementer = new web3.eth.Contract(abi);

  // 7. Create constructor transaction
  const incrementerTx = incrementer.deploy({
    data: bytecode,
    arguments: [5],
  });

  // 8. Sign transaction with PK
  const createTransaction = await web3.eth.accounts.signTransaction(
    {
      data: incrementerTx.encodeABI(),
      gas: await incrementerTx.estimateGas(),
      gasPrice: await web3.eth.getGasPrice(),
      nonce: await web3.eth.getTransactionCount(accountFrom.address),
    },
    accountFrom.privateKey
  );

  // 9. Send transaction and wait for receipt
  const createReceipt = await web3.eth.sendSignedTransaction(
    createTransaction.rawTransaction
  );
  console.log(`Contract deployed at address: ${createReceipt.contractAddress}`);
};

// 10. Call deploy function
deploy();

View the complete script

// 1. Import web3 and the contract file
const { Web3 } = require('web3');
const contractFile = require('./compile');

// 2. Add the Web3 provider logic
const providerRPC = {
  development: 'http://localhost:9944',
  phron: 'https://testnet.phron.ai',
};
const web3 = new Web3(providerRPC.phron); // Change to correct network

// 3. Create address variables
const accountFrom = {
  privateKey: 'INSERT_YOUR_PRIVATE_KEY',
  address: 'INSERT_PUBLIC_ADDRESS_OF_PK',
};

// 4. Get the bytecode and API
const bytecode = contractFile.evm.bytecode.object;
const abi = contractFile.abi;

// 5. Create deploy function
const deploy = async () => {
  console.log(`Attempting to deploy from account ${accountFrom.address}`);

  // 6. Create contract instance
  const incrementer = new web3.eth.Contract(abi);

  // 7. Create constructor transaction
  const incrementerTx = incrementer.deploy({
    data: bytecode,
    arguments: [5],
  });

  // 8. Sign transaction with PK
  const createTransaction = await web3.eth.accounts.signTransaction(
    {
      data: incrementerTx.encodeABI(),
      gas: await incrementerTx.estimateGas(),
      gasPrice: await web3.eth.getGasPrice(),
      nonce: await web3.eth.getTransactionCount(accountFrom.address),
    },
    accountFrom.privateKey
  );

  // 9. Send transaction and wait for receipt
  const createReceipt = await web3.eth.sendSignedTransaction(
    createTransaction.rawTransaction
  );
  console.log(`Contract deployed at address: ${createReceipt.contractAddress}`);
};

// 10. Call deploy function
deploy();

To run the script, you can enter the following command into your terminal:

node deploy.js

If successful, the contract's address will be displayed in the terminal.

node deploy.jsAttempting to deploy from account 0x3B939FeaD1557C741Ff06492FD0127bd287A421eContract deployed at address: 0x6dcb33a7f6235e74fd553b50c96f900707142892

Read Contract Data (Call Methods)

To get started, you can create a file and name it get.js:

touch get.js

Then you can take the following steps to create the script:

Import the abi from the compile.js file
Set up the Web3 provider
Create the contractAddress variable using the address of the deployed contract
Create an instance of the contract using the web3.eth.Contract function and passing in the abi and contractAddress
Create the asynchronous get function
Use the contract instance to call one of the contract's methods and pass in any inputs if necessary. For this example, you will call the number method which doesn't require any inputs. You can use await, which will return the value requested once the request promise resolves
Lastly, call the get function

// 1. Import the contract ABI
const { abi } = require('./compile');

// 2. Add the Web3 provider logic
// {...}

// 3. Create address variables
const contractAddress = 'INSERT_CONTRACT_ADDRESS';

// 4. Create contract instance
const incrementer = new web3.eth.Contract(abi, contractAddress);

// 5. Create get function
const get = async () => {
  console.log(`Making a call to contract at address: ${contractAddress}`);

  // 6. Call contract
  const data = await incrementer.methods.number().call();

  console.log(`The current number stored is: ${data}`);
};

// 7. Call get function
get();

View the complete script

// 1. Import Web3js and the contract ABI
const { Web3 } = require('web3');
const { abi } = require('./compile');

// 2. Add the Web3 provider logic
const providerRPC = {
  development: 'http://localhost:9944',
  phron: 'https://testnet.phron.ai',
};
const web3 = new Web3(providerRPC.phron); // Change to correct network

// 3. Create address variables
const contractAddress = 'INSERT_CONTRACT_ADDRESS';

// 4. Create contract instance
const incrementer = new web3.eth.Contract(abi, contractAddress);

// 5. Create get function
const get = async () => {
  console.log(`Making a call to contract at address: ${contractAddress}`);

  // 6. Call contract
  const data = await incrementer.methods.number().call();

  console.log(`The current number stored is: ${data}`);
};

// 7. Call get function
get();

To run the script, you can enter the following command in your terminal:

node get.js

If successful, the value will be displayed in the terminal.

Interact with Contract (Send Methods)

Send methods are the type of interaction that modifies the contract's storage (change variables), meaning a transaction needs to be signed and sent. In this section, you'll create two scripts: one to increment and one to reset the incrementer. To get started, you can create a file for each script and name them increment.js and reset.js:

touch increment.js reset.js

Open the increment.js file and take the following steps to create the script:

Import the abi from the compile.js file
Set up the Web3 provider
Define the privateKey for the origin account, the contractAddress of the deployed contract, and the _value to increment by. The private key is required to create a wallet instance. Note: This is for example purposes only. Never store your private keys in a JavaScript file
Create an instance of the contract using the web3.eth.Contract function and passing in the abi and contractAddress
Use the contract instance to build the increment transaction using the methods.increment function and passing in the _value as an input
Create the asynchronous increment function
Use the contract instance and the increment transaction you previously created to sign the transaction with the sender's private key. You'll use the web3.eth.accounts.signTransaction function and specify the to address, data, gas, gasPrice, and nonce for the transaction
Send the signed transaction using the web3.eth.sendSignedTransaction method and pass in the raw transaction. Then use await to wait until the transaction is processed and the transaction receipt is returned
Lastly, call the increment function

// 1. Import the contract ABI
const { abi } = require('./compile');

// 2. Add the Web3 provider logic
// {...}

// 3. Create variables
const accountFrom = {
  privateKey: 'INSERT_YOUR_PRIVATE_KEY',
  address: 'INSERT_PUBLIC_ADDRESS_OF_PK',
};
const contractAddress = 'INSERT_CONTRACT_ADDRESS';
const _value = 3;

// 4. Create contract instance
const incrementer = new web3.eth.Contract(abi, contractAddress);

// 5. Build the increment transaction
const incrementTx = incrementer.methods.increment(_value);

// 6. Create increment function
const increment = async () => {
  console.log(
    `Calling the increment by ${_value} function in contract at address: ${contractAddress}`
  );

  // 7. Sign transaction with PK
  const createTransaction = await web3.eth.accounts.signTransaction(
    {
      to: contractAddress,
      data: incrementTx.encodeABI(),
      gas: await incrementTx.estimateGas(),
      gasPrice: await web3.eth.getGasPrice(),
      nonce: await web3.eth.getTransactionCount(accountFrom.address),
    },
    accountFrom.privateKey
  );

  // 8. Send transaction and wait for receipt
  const createReceipt = await web3.eth.sendSignedTransaction(
    createTransaction.rawTransaction
  );
  console.log(`Tx successful with hash: ${createReceipt.transactionHash}`);
};

// 9. Call increment function
increment();

View the complete script

// 1. Import Web3js and the contract ABI
const { Web3 } = require('web3');
const { abi } = require('./compile');

// 2. Add the Web3 provider logic
const providerRPC = {
  development: 'http://localhost:9944',
  phron: 'https://testnet.phron.ai',
};
const web3 = new Web3(providerRPC.phron); // Change to correct network

// 3. Create variables
const accountFrom = {
  privateKey: 'INSERT_YOUR_PRIVATE_KEY',
  address: 'INSERT_PUBLIC_ADDRESS_OF_PK',
};
const contractAddress = 'INSERT_CONTRACT_ADDRESS';
const _value = 3;

// 4. Create contract instance
const incrementer = new web3.eth.Contract(abi, contractAddress);

// 5. Build increment transaction
const incrementTx = incrementer.methods.increment(_value);

// 6. Create increment function
const increment = async () => {
  console.log(
    `Calling the increment by ${_value} function in contract at address: ${contractAddress}`
  );

  // 7. Sign transaction with PK
  const createTransaction = await web3.eth.accounts.signTransaction(
    {
      to: contractAddress,
      data: incrementTx.encodeABI(),
      gas: await incrementTx.estimateGas(),
      gasPrice: await web3.eth.getGasPrice(),
      nonce: await web3.eth.getTransactionCount(accountFrom.address),
    },
    accountFrom.privateKey
  );

  // 8. Send transaction and wait for receipt
  const createReceipt = await web3.eth.sendSignedTransaction(
    createTransaction.rawTransaction
  );
  console.log(`Tx successful with hash: ${createReceipt.transactionHash}`);
};

// 9. Call increment function
increment();

To run the script, you can enter the following command in your terminal:

node increment.js

If successful, the transaction hash will be displayed in the terminal. You can use the get.js script alongside the increment.js script to make sure that value is changing as expected:

node get.jsMaking a call to contract at address: 0x6dcb33a7f6235e74fd553b50c96f900707142892The current number stored is: 5node increment.jsCalling the increment by 3 function in contract at address: 0x6dcb33a7f6235e74fd553b50c96f900707142892Tx successful with hash: 0xb03d1426376e7efc49d8b6c69aaf91e548578db7fd4a9ba575dbd8030821f6a3node get.jsMaking a call to contract at address: 0x6dcb33a7f6235e74fd553b50c96f900707142892The current number stored is: 8

Next, you can open the reset.js file and take the following steps to create the script:

Import the abi from the compile.js file
Set up the Web3 provider
Define the privateKey for the origin account and the contractAddress of the deployed contract. The private key is required to create a wallet instance. Note: This is for example purposes only. Never store your private keys in a JavaScript file
Create an instance of the contract using the web3.eth.Contract function and passing in the abi and contractAddress
Use the contract instance to build the reset transaction using the methods.reset function
Create the asynchronous reset function
Use the contract instance and the reset transaction you previously created to sign the transaction with the sender's private key. You'll use the web3.eth.accounts.signTransaction function and specify the to address, data, gas, gasPrice, and nonce for the transaction
Send the signed transaction using the web3.eth.sendSignedTransaction method and pass in the raw transaction. Then use await to wait until the transaction is processed and the transaction receipt is returned
Lastly, call the reset function

// 1. Import the contract ABI
const { abi } = require('./compile');

// 2. Add the Web3 provider logic
// {...}

// 3. Create variables
const accountFrom = {
  privateKey: 'INSERT_YOUR_PRIVATE_KEY',
  address: 'INSERT_PUBLIC_ADDRESS_OF_PK',
};
const contractAddress = 'INSERT_CONTRACT_ADDRESS';

// 4. Create a contract instance
const incrementer = new web3.eth.Contract(abi, contractAddress);

// 5. Build reset transaction
const resetTx = incrementer.methods.reset();

// 6. Create reset function
const reset = async () => {
  console.log(
    `Calling the reset function in contract at address: ${contractAddress}`
  );

  // 7. Sign transaction with PK
  const createTransaction = await web3.eth.accounts.signTransaction(
    {
      to: contractAddress,
      data: resetTx.encodeABI(),
      gas: await resetTx.estimateGas(),
      gasPrice: await web3.eth.getGasPrice(),
      nonce: await web3.eth.getTransactionCount(accountFrom.address),
    },
    accountFrom.privateKey
  );

  // 8. Send transaction and wait for receipt
  const createReceipt = await web3.eth.sendSignedTransaction(
    createTransaction.rawTransaction
  );
  console.log(`Tx successful with hash: ${createReceipt.transactionHash}`);
};

// 9. Call reset function
reset();

View the complete script

// 1. Import Web3js and the contract ABI
const { Web3 } = require('web3');
const { abi } = require('./compile');

// 2. Add the Web3 provider logic
const providerRPC = {
  development: 'http://localhost:9944',
  phron: 'https://testnet.phron.ai',
};
const web3 = new Web3(providerRPC.phron); // Change to correct network

// 3. Create variables
const accountFrom = {
  privateKey: 'INSERT_YOUR_PRIVATE_KEY',
  address: 'INSERT_PUBLIC_ADDRESS_OF_PK',
};
const contractAddress = 'INSERT_CONTRACT_ADDRESS';

// 4. Create contract instance
const incrementer = new web3.eth.Contract(abi, contractAddress);

// 5. Build reset transaction
const resetTx = incrementer.methods.reset();

// 6. Create reset function
const reset = async () => {
  console.log(`Calling the reset function in contract at address: ${contractAddress}`);

  // 7. Sign transaction with PK
  const createTransaction = await web3.eth.accounts.signTransaction(
    {
      to: contractAddress,
      data: resetTx.encodeABI(),
      gas: await resetTx.estimateGas(),
      gasPrice: await web3.eth.getGasPrice(),
      nonce: await web3.eth.getTransactionCount(accountFrom.address),
    },
    accountFrom.privateKey
  );

  // 8. Send transaction and wait for receipt
  const createReceipt = await web3.eth.sendSignedTransaction(createTransaction.rawTransaction);
  console.log(`Tx successful with hash: ${createReceipt.transactionHash}`);
};

// 9. Call reset function
reset();

To run the script, you can enter the following command in your terminal:

node reset.js

If successful, the transaction hash will be displayed in the terminal. You can use the get.js script alongside the reset.js script to make sure that value is changing as expected:

node get.jsMaking a call to contract at address: 0x6dcb33a7f6235e74fd553b50c96f900707142892The current number stored is: 8node reset.jsCalling the reset function in contract at address: 0x6dcb33a7f6235e74fd553b50c96f900707142892Tx successful with hash: 0x557e908ca4da05d5af50983dbc116fbf8049bb2e86b9ec1e9f7d3f516b8a4c55node get.jsMaking a call to contract at address: 0x6dcb33a7f6235e74fd553b50c96f900707142892The current number stored is: 0

Web3.py

Web3.py Python Library

Introduction

Web3.py is a set of libraries that allow developers to interact with Ethereum nodes using HTTP, IPC, or WebSocket protocols with Python. Phron has an Ethereum-like API available that is fully compatible with Ethereum-style JSON-RPC invocations. Therefore, developers can leverage this compatibility and use the Web3.py library to interact with a Phron python3 as if they were doing so on Ethereum.

In this guide, you'll learn how to use the Web3.py library to send a transaction and deploy a contract on Phron.

Checking Prerequisites

For the examples in this guide, you will need to have the following:

An account with funds. You can get DEV tokens for testing on Phron once every 24 hours from the Phron Faucet
To test out the examples in this guide on Phron, you will need to have your own endpoint and API key, which you can get from one of the supported Endpoint Providers

Note
The examples in this guide assume you have a MacOS or Ubuntu 22.04-based environment and will need to be adapted accordingly for Windows.

Create a Python Project

To get started, you can create a directory to store all of the files you'll be creating throughout this guide:

mkdir web3-examples && cd web3-examples

For this guide, you'll need to install the Web3.py library and the Solidity compiler. To install both packages, you can run the following command:

pip3 install web3 py-solc-x solc-select

Setup Web3.py with Phron

Throughout this guide, you'll be creating a bunch of scripts that provide different functionalities, such as sending a transaction, deploying a contract, and interacting with a deployed contract. In most of these scripts, you'll need to create a Web3.py provider to interact with the network.

To configure your project for Phron, you will need to have your own endpoint and API key, which you can get from one of the supported Endpoint Providers.

To create a provider, you can take the following steps:

Import the web3 library
Create the web3 provider using the Web3(Web3.HTTPProvider()) method and providing the endpoint URL

# 1. Import web3.py
from web3 import Web3

# 2. Create web3.py provider
web3 = Web3(Web3.HTTPProvider("INSERT_RPC_API_ENDPOINT")) # Insert your RPC URL here

Save this code snippet, as you'll need it for the scripts that are used in the following sections.

Send a Transaction

You can also use the balance script to check the account balances after the transaction has been sent.

Check Balances Script

You'll only need one file to check the balances of both addresses before and after the transaction is sent. To get started, you can create a balances.py file by running:

touch balances.py

Next, you will create the script for this file and complete the following steps:

Set up the Web3 provider
Define the address_from and address_to variables
Get the balance for the accounts using the web3.eth.get_balance function and format the results using the web3.from_wei

from web3 import Web3

# 1. Add the Web3 provider logic here:
provider_rpc = {
    "development": "http://localhost:9944",
    "phron": "https://testnet.phron.ai",
}
web3 = Web3(Web3.HTTPProvider(provider_rpc["phron"]))  # Change to correct network

# 2. Create address variables
address_from = 'INSERT_FROM_ADDRESS'
address_to = 'INSERT_TO_ADDRESS'

# 3. Fetch balance data
balance_from = web3.from_wei(
    web3.eth.get_balance(Web3.to_checksum_address(address_from)), "ether"
)
balance_to = web3.from_wei(
    web3.eth.get_balance(Web3.to_checksum_address(address_to)), "ether"
)

print(f"The balance of { address_from } is: { balance_from } DEV")
print(f"The balance of { address_to } is: { balance_to } DEV")

To run the script and fetch the account balances, you can run the following command:

python3 balances.py

If successful, the balances for the origin and receiving address will be displayed in your terminal in ETH.

Send Transaction Script

touch transaction.py

Next, you will create the script for this file and complete the following steps:

Add imports, including Web3.py and the rpc_gas_price_strategy, which will be used in the following steps to get the gas price used for the transaction
Set up the Web3 provider
Define the account_from, including the private_key, and the address_to variables. The private key is required to sign the transaction. Note: This is for example purposes only. Never store your private keys in a Python file
Use the Web3.py Gas Price API to set a gas price strategy. For this example, you'll use the imported rpc_gas_price_strategy
Create and sign the transaction using the web3.eth.account.sign_transaction function. Pass in the nonce gas, gasPrice, to, and value for the transaction along with the sender's private_key. To get the nonce you can use the web3.eth.get_transaction_count function and pass in the sender's address. To predetermine the gasPrice you'll use the web3.eth.generate_gas_price function. For the value, you can format the amount to send from an easily readable format to Wei using the web3.to_wei function
Using the signed transaction, you can then send it using the web3.eth.send_raw_transaction function and wait for the transaction receipt by using the web3.eth.wait_for_transaction_receipt function

# 1. Add imports
from web3.gas_strategies.rpc import rpc_gas_price_strategy
from web3 import Web3

# 2. Add the Web3 provider logic here:
provider_rpc = {
    "development": "http://localhost:9944",
    "phron": "https://testnet.phron.ai",
}
web3 = Web3(Web3.HTTPProvider(provider_rpc["phron"]))  # Change to correct network

# 3. Create address variables
account_from = {
    'private_key': 'INSERT_YOUR_PRIVATE_KEY',
    'address': 'INSERT_PUBLIC_ADDRESS_OF_PK',
}
address_to = 'INSERT_TO_ADDRESS'

print(
    f'Attempting to send transaction from { account_from["address"] } to { address_to }'
)

# 4. Set the gas price strategy
web3.eth.set_gas_price_strategy(rpc_gas_price_strategy)

# 5. Sign tx with PK
tx_create = web3.eth.account.sign_transaction(
    {
        "nonce": web3.eth.get_transaction_count(
            Web3.to_checksum_address(account_from["address"])
        ),
        "gasPrice": web3.eth.generate_gas_price(),
        "gas": 21000,
        "to": Web3.to_checksum_address(address_to),
        "value": web3.to_wei("1", "ether"),
    },
    account_from["private_key"],
)

# 6. Send tx and wait for receipt
tx_hash = web3.eth.send_raw_transaction(tx_create.rawTransaction)
tx_receipt = web3.eth.wait_for_transaction_receipt(tx_hash)

print(f"Transaction successful with hash: { tx_receipt.transactionHash.hex() }")

To run the script, you can run the following command in your terminal:

python3 transaction.py

If the transaction was succesful, in your terminal you'll see the transaction hash has been printed out.

You can also use the balances.py script to check that the balances for the origin and receiving accounts have changed. The entire workflow would look like this:

python3 balances.pyThe balance of 0x3B939FeaD1557C741Ff06492FD0127bd287A421e is: 3563.79 DEVThe balance of 0x9Bf5Ae10540a1ab9B363bEA02A9406E6b2efA9af is: 0 DEVpython3 transaction.pyAttempting to send transaction from 0x3B939FeaD1557C741Ff06492FD0127bd287A421e to 0x9Bf5Ae10540a1ab9B363bEA02A9406E6b2efA9afTransaction successful with hash: 0xac70452510657ed43c27510578d3ce4b3b880d4cca1a24ade1497c6e0ee7f5d6python3 balances.pyThe balance of 0x3B939FeaD1557C741Ff06492FD0127bd287A421e is: 3562.79 DEVThe balance of 0x9Bf5Ae10540a1ab9B363bEA02A9406E6b2efA9af is: 1 DEV

Deploy a Contract

touch Incrementer.sol

Next, you can add the Solidity code to the file:

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

contract Incrementer {
    uint256 public number;

    constructor(uint256 _initialNumber) {
        number = _initialNumber;
    }

    function increment(uint256 _value) public {
        number = number + _value;
    }

    function reset() public {
        number = 0;
    }
}

Note
This contract is a simple example for illustration purposes only and does not handle values wrapping around.

Compile Contract Script

touch compile.py

Next, you will create the script for this file and complete the following steps:

Import the solcx package
Optional - If you haven't already installed the Solidity compiler, you can do so with by using the solcx.install_solc function
Compile the Incrementer.sol function using the solcx.compile_files function
Export the contract's ABI and bytecode

# 1. Import solcx
import solcx

# 2. If you haven't already installed the Solidity compiler, uncomment the following line
# solcx.install_solc()

# 3. Compile contract
temp_file = solcx.compile_files(
    'Incrementer.sol',
    output_values=['abi', 'bin'],
    # solc_version='0.8.19'
)

# 4. Export contract data
abi = temp_file['Incrementer.sol:Incrementer']['abi']
bytecode = temp_file['Incrementer.sol:Incrementer']['bin']

Note
If you see an error stating that Solc is not installed, uncomment step 2 described in the code snippet.

Deploy Contract Script

touch deploy.py

Next, you will create the script for this file and complete the following steps:

Add imports, including Web3.py and the ABI and bytecode of the Incrementer.sol contract
Set up the Web3 provider
Define the account_from, including the private_key. The private key is required to sign the transaction. Note: This is for example purposes only. Never store your private keys in a Python file
Create a contract instance using the web3.eth.contract function and passing in the ABI and bytecode of the contract
Build a constructor transaction using the contract instance and passing in the value to increment by. For this example, you can use 5. You'll then use the build_transaction function to pass in the transaction information including the from address and the nonce for the sender. To get the nonce you can use the web3.eth.get_transaction_count function
Sign the transaction using the web3.eth.account.sign_transaction function and pass in the constructor transaction and the private_key of the sender
Using the signed transaction, you can then send it using the web3.eth.send_raw_transaction function and wait for the transaction receipt by using the web3.eth.wait_for_transaction_receipt function

# 1. Add imports
from compile import abi, bytecode
from web3 import Web3

# 2. Add the Web3 provider logic here:
provider_rpc = {
    "development": "http://localhost:9944",
    "phron": "https://testnet.phron.ai",
}
web3 = Web3(Web3.HTTPProvider(provider_rpc["phron"]))  # Change to correct network

# 3. Create address variable
account_from = {
    'private_key': 'INSERT_YOUR_PRIVATE_KEY',
    'address': 'INSERT_PUBLIC_ADDRESS_OF_PK',
}

print(f'Attempting to deploy from account: { account_from["address"] }')

# 4. Create contract instance
Incrementer = web3.eth.contract(abi=abi, bytecode=bytecode)

# 5. Build constructor tx
construct_txn = Incrementer.constructor(5).build_transaction(
    {
        "from": Web3.to_checksum_address(account_from["address"]),
        "nonce": web3.eth.get_transaction_count(
            Web3.to_checksum_address(account_from["address"])
        ),
    }
)

# 6. Sign tx with PK
tx_create = web3.eth.account.sign_transaction(
    construct_txn, account_from["private_key"]
)

# 7. Send tx and wait for receipt
tx_hash = web3.eth.send_raw_transaction(tx_create.rawTransaction)
tx_receipt = web3.eth.wait_for_transaction_receipt(tx_hash)

print(f"Contract deployed at address: { tx_receipt.contractAddress }")

To run the script, you can enter the following command into your terminal:

python3 deploy.py

If successful, the contract's address will be displayed in the terminal.

python3 deploy.pyAttempting to deploy from account: 0x3B939FeaD1557C741Ff06492FD0127bd287A421eContract deployed at address: 0xFef3cFb8eE1FE727b3848E551ae5DC8903237B08

Read Contract Data (Call Methods)

To get started, you can create a file and name it get.py:

touch get.py

Then you can take the following steps to create the script:

Add imports, including Web3.py and the ABI of the Incrementer.sol contract
Set up the Web3 provider
Define the contract_address of the deployed contract
Create a contract instance using the web3.eth.contract function and passing in the ABI and address of the deployed contract
Using the contract instance, you can then call the number function

# 1. Import the ABI
from compile import abi
from web3 import Web3

# 2. Add the Web3 provider logic here:
provider_rpc = {
    "development": "http://localhost:9944",
    "phron": "https://testnet.phron.ai",
}
web3 = Web3(Web3.HTTPProvider(provider_rpc["phron"]))  # Change to correct network

# 3. Create address variable
contract_address = 'INSERT_CONTRACT_ADDRESS'

print(f"Making a call to contract at address: { contract_address }")

# 4. Create contract instance
Incrementer = web3.eth.contract(address=contract_address, abi=abi)

# 5. Call Contract
number = Incrementer.functions.number().call()
print(f"The current number stored is: { number } ")

To run the script, you can enter the following command in your terminal:

python3 get.py

If successful, the value will be displayed in the terminal.

Interact with Contract (Send Methods)

touch increment.py reset.py

Open the increment.py file and take the following steps to create the script:

Add imports, including Web3.py and the ABI of the Incrementer.sol contract
Set up the Web3 provider
Define the account_from, including the private_key, the contract_address of the deployed contract, and the value to increment by. The private key is required to sign the transaction. Note: This is for example purposes only. Never store your private keys in a Python file
Create a contract instance using the web3.eth.contract function and passing in the ABI and address of the deployed contract
Build the increment transaction using the contract instance and passing in the value to increment by. You'll then use the build_transaction function to pass in the transaction information including the from address and the nonce for the sender. To get the nonce you can use the web3.eth.get_transaction_count function
Sign the transaction using the web3.eth.account.sign_transaction function and pass in the increment transaction and the private_key of the sender
Using the signed transaction, you can then send it using the web3.eth.send_raw_transaction function and wait for the transaction receipt by using the web3.eth.wait_for_transaction_receipt function

# 1. Add imports
from compile import abi
from web3 import Web3

# 2. Add the Web3 provider logic here:
provider_rpc = {
    "development": "http://localhost:9944",
    "phron": "https://testnet.phron.ai",
}
web3 = Web3(Web3.HTTPProvider(provider_rpc["phron"]))  # Change to correct network

# 3. Create variables
account_from = {
    'private_key': 'INSERT_YOUR_PRIVATE_KEY',
    'address': 'INSERT_PUBLIC_ADDRESS_OF_PK',
}
contract_address = 'INSERT_CONTRACT_ADDRESS'
value = 3

print(
    f"Calling the increment by { value } function in contract at address: { contract_address }"
)

# 4. Create contract instance
Incrementer = web3.eth.contract(address=contract_address, abi=abi)

# 5. Build increment tx
increment_tx = Incrementer.functions.increment(value).build_transaction(
    {
        "from": Web3.to_checksum_address(account_from["address"]),
        "nonce": web3.eth.get_transaction_count(
            Web3.to_checksum_address(account_from["address"])
        ),
    }
)

# 6. Sign tx with PK
tx_create = web3.eth.account.sign_transaction(increment_tx, account_from["private_key"])

# 7. Send tx and wait for receipt
tx_hash = web3.eth.send_raw_transaction(tx_create.rawTransaction)
tx_receipt = web3.eth.wait_for_transaction_receipt(tx_hash)

print(f"Tx successful with hash: { tx_receipt.transactionHash.hex() }")

To run the script, you can enter the following command in your terminal:

python3 increment.py

If successful, the transaction hash will be displayed in the terminal. You can use the get.py script alongside the increment.py script to make sure that value is changing as expected:

python get.pyMaking a call to contract at address: 0xFef3cFb8eE1FE727b3848E551ae5DC8903237B08The current number stored is: 5python increment.pyCalling the increment by 3 function in contract at address: 0xFef3cFb8eE1FE727b3848E551ae5DC8903237B08Tx successful with hash: 0x47757fd97e3ef8db973e335d1f2d19c46b37d0dbd53fea1636ec559ccf119a13python get.pyMaking a call to contract at address: 0xFef3cFb8eE1FE727b3848E551ae5DC8903237B08The current number stored is: 8

Next you can open the reset.py file and take the following steps to create the script:

Add imports, including Web3.py and the ABI of the Incrementer.sol contract
Set up the Web3 provider
Define the account_from, including the private_key, and the contract_address of the deployed contract. The private key is required to sign the transaction. Note: This is for example purposes only. Never store your private keys in a Python file
Create a contract instance using the web3.eth.contract function and passing in the ABI and address of the deployed contract
Build the reset transaction using the contract instance. You'll then use the build_transaction function to pass in the transaction information including the from address and the nonce for the sender. To get the nonce you can use the web3.eth.get_transaction_count function
Sign the transaction using the web3.eth.account.sign_transaction function and pass in the reset transaction and the private_key of the sender
Using the signed transaction, you can then send it using the web3.eth.send_raw_transaction function and wait for the transaction receipt by using the web3.eth.wait_for_transaction_receipt function

# 1. Add imports
from compile import abi
from web3 import Web3

# 2. Add the Web3 provider logic here:
provider_rpc = {
    "development": "http://localhost:9944",
    "phron": "https://testnet.phron.ai",
}
web3 = Web3(Web3.HTTPProvider(provider_rpc["phron"]))  # Change to correct network

# 3. Create variables
account_from = {
    'private_key': 'INSERT_YOUR_PRIVATE_KEY',
    'address': 'INSERT_PUBLIC_ADDRESS_OF_PK',
}
contract_address = 'INSERT_CONTRACT_ADDRESS'

print(f"Calling the reset function in contract at address: { contract_address }")

# 4. Create contract instance
Incrementer = web3.eth.contract(address=contract_address, abi=abi)

# 5. Build reset tx
reset_tx = Incrementer.functions.reset().build_transaction(
    {
        "from": Web3.to_checksum_address(account_from["address"]),
        "nonce": web3.eth.get_transaction_count(
            Web3.to_checksum_address(account_from["address"])
        ),
    }
)

# 6. Sign tx with PK
tx_create = web3.eth.account.sign_transaction(reset_tx, account_from["private_key"])

# 7. Send tx and wait for receipt
tx_hash = web3.eth.send_raw_transaction(tx_create.rawTransaction)
tx_receipt = web3.eth.wait_for_transaction_receipt(tx_hash)

print(f"Tx successful with hash: { tx_receipt.transactionHash.hex() }")

To run the script, you can enter the following command in your terminal:

python3 reset.py

If successful, the transaction hash will be displayed in the terminal. You can use the get.py script alongside the reset.py script to make sure that value is changing as expected:

python get.pyMaking a call to contract at address: 0xFef3cFb8eE1FE727b3848E551ae5DC8903237B08The current number stored is: 8python reset.pyCalling the reset function in contract at address: 0xFef3cFb8eE1FE727b3848E551ae5DC8903237B08Tx successful with hash: 0x152f07430b524838da848b44d58577db252681fba6fbeaf117b2f9d432e301b2python get.pyMaking a call to contract at address: 0xFef3cFb8eE1FE727b3848E551ae5DC8903237B08The current number stored is: 0