@solana/web3.js

What is @solana/web3.js?

@solana/web3.js is a JavaScript library for interacting with the Solana blockchain. It provides a set of tools and utilities for developers to build applications on Solana, including functionalities for managing accounts, sending transactions, interacting with smart contracts, and querying blockchain data.

What are @solana/web3.js's main functionalities?

Create and Manage Accounts

This feature allows you to create and manage Solana accounts. The code sample demonstrates how to generate a new keypair, which includes a public key and a secret key.

const solanaWeb3 = require('@solana/web3.js');

// Generate a new keypair
const keypair = solanaWeb3.Keypair.generate();
console.log('Public Key:', keypair.publicKey.toBase58());
console.log('Secret Key:', keypair.secretKey);

Send Transactions

This feature allows you to send transactions on the Solana blockchain. The code sample demonstrates how to create a connection to the Solana devnet, airdrop SOL to an account, create a transaction to transfer SOL, and send the transaction.

const solanaWeb3 = require('@solana/web3.js');

(async () => {
  const connection = new solanaWeb3.Connection(solanaWeb3.clusterApiUrl('devnet'), 'confirmed');
  const from = solanaWeb3.Keypair.generate();
  const to = solanaWeb3.Keypair.generate();

  // Airdrop SOL to the from account
  await connection.requestAirdrop(from.publicKey, solanaWeb3.LAMPORTS_PER_SOL);

  // Create a transaction
  const transaction = new solanaWeb3.Transaction().add(
    solanaWeb3.SystemProgram.transfer({
      fromPubkey: from.publicKey,
      toPubkey: to.publicKey,
      lamports: solanaWeb3.LAMPORTS_PER_SOL / 100,
    })
  );

  // Sign and send the transaction
  const signature = await solanaWeb3.sendAndConfirmTransaction(connection, transaction, [from]);
  console.log('Transaction signature:', signature);
})();

Interact with Smart Contracts

This feature allows you to interact with smart contracts deployed on the Solana blockchain. The code sample demonstrates how to create a transaction that calls a smart contract and send the transaction.

const solanaWeb3 = require('@solana/web3.js');

(async () => {
  const connection = new solanaWeb3.Connection(solanaWeb3.clusterApiUrl('devnet'), 'confirmed');
  const programId = new solanaWeb3.PublicKey('YourProgramIdHere');
  const account = solanaWeb3.Keypair.generate();

  // Create a transaction to call a smart contract
  const transaction = new solanaWeb3.Transaction().add(
    new solanaWeb3.TransactionInstruction({
      keys: [{ pubkey: account.publicKey, isSigner: true, isWritable: true }],
      programId,
      data: Buffer.alloc(0), // Add your instruction data here
    })
  );

  // Sign and send the transaction
  const signature = await solanaWeb3.sendAndConfirmTransaction(connection, transaction, [account]);
  console.log('Transaction signature:', signature);
})();

Query Blockchain Data

This feature allows you to query data from the Solana blockchain. The code sample demonstrates how to get account information and the recent blockhash from the blockchain.

const solanaWeb3 = require('@solana/web3.js');

(async () => {
  const connection = new solanaWeb3.Connection(solanaWeb3.clusterApiUrl('devnet'), 'confirmed');
  const publicKey = new solanaWeb3.PublicKey('YourPublicKeyHere');

  // Get account info
  const accountInfo = await connection.getAccountInfo(publicKey);
  console.log('Account Info:', accountInfo);

  // Get recent blockhash
  const recentBlockhash = await connection.getRecentBlockhash();
  console.log('Recent Blockhash:', recentBlockhash);
})();

Other packages similar to @solana/web3.js

web3

web3.js is a collection of libraries that allow you to interact with a local or remote Ethereum node using HTTP, IPC, or WebSocket. It provides similar functionalities to @solana/web3.js but is designed for the Ethereum blockchain.

ethers

ethers.js is a library for interacting with the Ethereum blockchain and its ecosystem. It provides a more lightweight and modular approach compared to web3.js and includes functionalities for managing accounts, sending transactions, and interacting with smart contracts.

near-api-js

near-api-js is a JavaScript library for interacting with the NEAR blockchain. It provides similar functionalities to @solana/web3.js, including account management, transaction handling, and smart contract interaction, but is designed specifically for the NEAR blockchain.

README

Solana JavaScript API

This is the Solana Javascript API built on the Solana JSON RPC API

Latest API Documentation

Installation

Yarn

$ yarn add @solana/web3.js

npm

$ npm install --save @solana/web3.js

Browser bundle

<script src="https://github.com/solana-labs/solana-web3.js/releases/download/v0.0.6/solanaWeb3.min.js"></script>

BPF program development

The Solana BPF SDK is located in the bpf-sdk/ subdirectory if you installed solana-web3.js from npmjs.com.

From a git clone, run npm run bpf-sdk:install to fetch the latest BPF SDK.

Additionally Rust must be installed to build Rust BPF programs such as examples/bpf-rust-noop/. See https://www.rust-lang.org/install.html for installation details.

Usage

Javascript

const solanaWeb3 = require('@solana/web3.js');
console.log(solanaWeb3);

ES6

import solanaWeb3 from '@solana/web3.js';
console.log(solanaWeb3);

Browser bundle

// `solanaWeb3` is provided in the global namespace by the `solanaWeb3.min.js` script bundle.
console.log(solanaWeb3);

Local Network

The solana-localnet program is provided to easily start a test Solana cluster locally on your machine. Docker must be installed. The JSON RPC endpoint of the local cluster is http://localhost:8899.

To start, first fetch the latest Docker image by running:

$ npx solana-localnet update

Then run the following command to start the cluster

$ npx solana-localnet up

While the cluster is running logs are available with:

$ npx solana-localnet logs -f

Stop the cluster with:

$ npx solana-localnet down

Flow

A Flow library definition is provided at module.flow.js. Add the following line under the [libs] section of your project's .flowconfig to activate it:

[libs]
node_modules/@solana/web3.js/module.flow.js

Examples

See the examples/ directory for small snippets.

Standalone examples:

• Message feed (BPF Rust and C): https://github.com/solana-labs/example-messagefeed
• Tic-tac-toe (BPF C): https://github.com/solana-labs/example-tictactoe
• Web wallet: https://github.com/solana-labs/example-webwallet

Releases

Releases are available on Github and npmjs.com

Each Github release features a tarball containing API documentation and a minified version of the module suitable for direct use in a browser environment (<script> tag)