How to Send Transactions with Solana Web3.js 2.0

10 min read

Overview

Solana recently announced the release candidate for Solana Web3.js 2.0, a major update to their JavaScript library for interacting with the Solana blockchain. This guide will teach you the basics of sending transactions using this new library.

Let's dive in!

What You Will Do

Write a script to perform basic Solana transactions using the Solana Web3.js 2.0 library:

Airdrop SOL using native RPC method and factory function
Create and send a transfer transaction using the new API

What You Will Need

Knowledge of Solana basics (Guide: Introduction to Solana)
Node.js (version 19 or higher) installed
TypeScript and ts-node installed
Solana CLI installed

Dependencies Used in this Guide

Dependency	Version
@solana/web3.js	^2.0.0 or higher
@solana-program/system	^0.5.0
solana cli	1.18.8

Let's get started!

What is Solana Web3.js 2.0?

Solana Web3.js 2.0 is a significant update to the JavaScript library for interacting with the Solana blockchain. It introduces a new API design focusing on composability, modularity, and improved developer experience. Some key features include:

Functional API: The new API uses a functional programming style, making it easier to compose complex operations.
Improved TypeScript support: Better type inference and stricter types for enhanced code safety.
Modular design: Functions are split into smaller, more focused modules, allowing for tree-shaking and smaller bundle sizes.
Enhanced error handling: More informative error messages and improved error types.

For more information on changes to the API, check out our (Blog: What's New in Solana Web3.js 2.0).

Let's explore these features by creating a script to perform a basic transfer transaction.

Create a New Project

First, let's set up our project:

mkdir solana-transfer-demo && cd solana-transfer-demo

Next, initialize your project as a Node.js project:

npm init -y

Install the dependencies:

npm install @solana/web3.js@2.0.0-rc.0 @solana-program/system && npm install --save-dev @types/node

Note: If you are using a version of Node.js older than 18, you may need to install the @solana-program/system package using the --legacy-peer-deps flag.

Add a tsconfig.json file to your project with resolveJsonModule enabled:

tsc --init --resolveJsonModule true

Create a new file called transfer.ts in your project directory.

echo > transfer.ts

Great. Let's write some code!

Import Dependencies

In your transfer.ts file, let's start by importing the necessary dependencies:

import {
    airdropFactory,
    createKeyPairSignerFromBytes,
    createSolanaRpc,
    createSolanaRpcSubscriptions,
    generateKeyPairSigner,
    lamports,
    sendAndConfirmTransactionFactory,
    pipe,
    createTransactionMessage,
    setTransactionMessageFeePayer,
    setTransactionMessageLifetimeUsingBlockhash,
    appendTransactionMessageInstruction,
    signTransactionMessageWithSigners,
    getSignatureFromTransaction,
    address,
} from "@solana/web3.js";
import { getTransferSolInstruction } from "@solana-program/system";

const LAMPORTS_PER_SOL = BigInt(1_000_000_000);

Here, we're importing various functions from the new Solana Web3.js 2.0 library. Note the functional style of the imports - each function is responsible for a specific task, promoting modularity and composability. The LAMPORTS_PER_SOL constant is no longer available via the SDK, so we must define it ourselves. Unlike the previous SDK, the new one utilizes bigints for all amounts (to be better compatible with Rust programming, which supports u64, a common type in Solana programs).

Create the Main Function

Next, let's create our main function that will house the logic of our script:

async function main() {
    // 1 - Establish connection to Solana cluster

    // 2 - Generate signers

    // 3 - Airdrop SOL to accounts

    // 4 - Create transfer transaction
    
    // 5 - Sign and send transaction
}

main();

Establish Connection to Solana Cluster

Inside the main function, let's establish a connection to our local Solana cluster:

    // 1 - Establish connection to Solana cluster
    const httpProvider = 'http://127.0.0.1:8899';
    const wssProvider = 'ws://127.0.0.1:8900';
    const rpc = createSolanaRpc(httpProvider);
    const rpcSubscriptions = createSolanaRpcSubscriptions(wssProvider);
    console.log(`✅ - Established connection to ${httpProvider}`);

Here, we're using the createSolanaRpc and createSolanaRpcSubscriptions functions to create our RPC connections. If you are familiar with the old SDK, you may notice that the new SDK uses a different approach to establishing connections. We will be using localhost for this guide, but if you are ready to connect to a remote Solana cluster, you can use your QuickNode HTTP Provider and WSS Provider endpoints from your QuickNode Dashboard.

If you do not already have a QuickNode account, you can create one for free here.

Generate Signers

Now, let's generate two signers for our transaction:

    // 2 - Generate signers
    const user1 = await generateKeyPairSigner();
    console.log(`✅ - New user1 address created: ${user1.address}`);
    const user2 = await createKeyPairSignerFromBytes(new Uint8Array([/* your secret key bytes here */]));
    console.log(`✅ - user2 address generated from file: ${user2.address}`);

For learning purposes, we will generate Keypairs in two ways. First, using generateKeyPairSigner to create a new keypair for user1, and createKeyPairSignerFromBytes to create a keypair for user2 from an existing secret key. If you do not already have a secret key, you can generate one using the Solana CLI:

solana-keygen new --no-bip39-passphrase --outfile ./my-keypair.json

If you would prefer to load the secret from a file, you can use the the import statement (since we used the --resolveJsonModule flag in our tsconfig.json file):

// Add to your imports
import secret from './my-keypair.json';

    // Replace the `user2` line below with the following:
    const user2 = await createKeyPairSignerFromBytes(new Uint8Array(secret));

Airdrop SOL to Accounts

Before we can transfer SOL, we need to fund our accounts. Again, for demonstration purposes, we will use two different methods (one using the native requestAirdrop method and the other using the airdropFactory function). Add the following code to the main function:

    // 3 - Airdrop SOL to accounts
    // Using RPC method
    const tx1 = await rpc.requestAirdrop(
        user1.address,
        lamports(LAMPORTS_PER_SOL),
        { commitment: 'processed' }
    ).send();
    console.log(`✅ - user1 airdropped 1 SOL using RPC methods`);
    console.log(`✅ - tx1: ${tx1}`);

    // Using factory function
    const airdrop = airdropFactory({ rpc, rpcSubscriptions });
    const tx2 = await airdrop({
        commitment: 'processed',
        lamports: lamports(LAMPORTS_PER_SOL),
        recipientAddress: user2.address
    });
    console.log(`✅ - user2 airdropped 1 SOL using Factory Function`);
    console.log(`✅ - tx2: ${tx2}`);

Both methods are equally viable, so you can choose whichever best suits your use case. Regardless of the approach, you will need to pass the destination address, the amount of SOL to airdrop (Note that the new SDK requires us to use the lamports function which effectively extends the bigint type), and the commitment level. In this case, we are using the lamports function to convert SOL to lamports, which is the unit of measure used by Solana.

Create and Send Transfer Transaction

Now, let's create and send our transfer transaction. This process showcases several essential features of the new Solana Web3.js 2.0 SDK:

    // 4 - Create transfer transaction
    const { value: latestBlockhash } = await rpc.getLatestBlockhash().send();

    const transactionMessage = pipe(
        createTransactionMessage({ version: 0 }),
        tx => setTransactionMessageFeePayer(user1.address, tx),
        tx => setTransactionMessageLifetimeUsingBlockhash(latestBlockhash, tx),
        tx => appendTransactionMessageInstruction(
            getTransferSolInstruction({
                amount: lamports(LAMPORTS_PER_SOL / BigInt(2)),
                destination: user2.address,
                source: user1,
            }),
            tx
        )
    );

Let's break this down:

RPC Calls and the .send() Method: The new SDK introduces a consistent pattern for making RPC calls using the .send() method. This is evident in the getLatestBlockhash() call:
```
const { value: latestBlockhash } = await rpc.getLatestBlockhash().send();
```
This pattern separates the construction of the RPC request from its execution, allowing for more flexibility and composability in making requests.
Using Pipes for Transaction Construction: The pipe function is a crucial feature in the new SDK, borrowed from functional programming concepts. If you're not familiar with pipes, they allow you to chain multiple operations together, passing the result of each operation as an input to the next.
```
const transactionMessage = pipe(
    createTransactionMessage({ version: 0 }),
    tx => setTransactionMessageFeePayer(user1.address, tx),
    // ... more operations
);
```
Each function in the pipe takes the result of the previous function as its input, modifying the transaction message step by step. This approach makes the transaction construction process more readable and maintainable, especially for complex transactions.
Program Instructions from Separate Libraries: The getTransferSolInstruction function is imported from the @solana-program/system library:
```
import { getTransferSolInstruction } from "@solana-program/system";
```
This separation of program-specific instructions into their own libraries is a new pattern in Web3.js 2.0. It allows for better code organization and easier management of different Solana programs. You can expect to see more program-specific libraries following this pattern, making interacting with various Solana programs easier.
Granular Transaction Construction: Notice how the transaction is assembled step by step:
- createTransactionMessage({ version: 0 }): Initializes a new transaction message.
- setTransactionMessageFeePayer: Sets the fee payer for the transaction.
- setTransactionMessageLifetimeUsingBlockhash: Sets the transaction's lifetime using a recent blockhash.
- appendTransactionMessageInstruction: Adds the transfer instruction to the transaction.
This granular approach gives developers more control over each aspect of the transaction and makes it easier to construct complex transactions with multiple instructions.
Type Safety and Immutability: Using separate functions for each step in transaction construction, combined with TypeScript, provides better type safety, ensuring that errors are caught early. Each function returns a new transaction object rather than modifying an existing one, promoting immutability and reducing the chance of unintended side effects.

By leveraging these features, the new Solana Web3.js 2.0 SDK aims to provide a more robust, flexible, and developer-friendly way to interact with the Solana blockchain. As you continue to work with the SDK, you'll find that these patterns make it easier to write clear, maintainable, and error-resistant code for your Solana applications.

Sign and Send Transaction

    // 5 - Sign and send transaction
    const signedTransaction = await signTransactionMessageWithSigners(transactionMessage);
    const sendAndConfirmTransaction = sendAndConfirmTransactionFactory({ rpc, rpcSubscriptions });

    try {
        await sendAndConfirmTransaction(
            signedTransaction,
            { commitment: 'confirmed', skipPreflight: true }
        );
        const signature = getSignatureFromTransaction(signedTransaction);
        console.log('✅ - Transfer transaction:', signature);
    } catch (e) {
        console.error('Transfer failed:', e);
    }

This section demonstrates several key features of Web3.js 2.0:

We use signTransactionMessageWithSigners to sign our transaction using any signers that may be stored in the account metas of the instruction accounts. If you look back at our getTransferSolInstruction function, you'll see that in the source parameter, we pass in the user1 Keypair (the signer for the source account). The signTransactionMessageWithSigners will then use that signer to sign the transaction.
We create a sendAndConfirmTransaction function using the sendAndConfirmTransactionFactory function.
Finally, we send the signed transaction using the sendAndConfirmTransaction function, and we return the transaction signature, which we obtain using the getSignatureFromTransaction function.

Set Up Local Environment

For this guide, we'll use a local Solana validator. Open a new terminal window and start the validator:

solana-test-validator -r

Run the Script

To run our script, use the following command:

ts-node transfer.ts

You should see output indicating successful connection, airdrop, and transfer transactions:

Great job!

Add More Instructions

If you would like, feel free to append additional instructions to the transfer transaction. For example, you could add the following instruction to your pipe to transfer SOL to another account:

        tx => appendTransactionMessageInstruction(
            getTransferSolInstruction({
                amount: lamports(LAMPORTS_PER_SOL / BigInt(3)),
                destination: address('SOME_OTHER_ADDRESS'),
                source: user1,
            }),
            tx
        )

Practicing is the best way to improve your skills, so feel free to experiment with different instructions and transactions. If you would like to see our source code for this guide, you can find it here. Happy coding!

Wrap Up

This guide explored the new Solana Web3.js 2.0 library by creating a script to perform a basic transfer transaction. Through its functional programming style and use of factory functions, the new API promotes modularity, composability, and improved developer experience.

Some key takeaways:

The new API allows for more granular control over transaction creation and signing.
Factory functions provide a way to create reusable, customizable functions.
The pipe function allows for clear and readable composition of operations.

As you continue to explore Web3.js 2.0, you'll discover even more powerful features and improvements. Happy coding!

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How to Send Transactions with Solana Web3.js 2.0

Overview​

What You Will Do​

What You Will Need​

Dependencies Used in this Guide​

What is Solana Web3.js 2.0?​

Create a New Project​

Import Dependencies​

Create the Main Function​

Establish Connection to Solana Cluster​

Generate Signers​

Airdrop SOL to Accounts​

Create and Send Transfer Transaction​

Sign and Send Transaction​

Set Up Local Environment​

Run the Script​

Add More Instructions​

Wrap Up​