starknet-js

starknet.js v9.x SDK

Related modules: skills catalog.

When to Use

• Building Starknet apps with provider, account, contract, wallet, or paymaster flows.

When NOT to Use

• Cairo contract authoring, deployment-only runbooks, or security audits.

Quick Start

npm install starknet

Minimal setup to read from Starknet:

import { RpcProvider, Contract } from 'starknet';

const provider = await RpcProvider.create({ nodeUrl: 'https://rpc.starknet.lava.build' });
const contract = new Contract(abi, contractAddress, provider);
const result = await contract.get_balance();

Core Architecture

Provider -> Account -> Contract
   |          |          |
Network   Identity   Interaction

• Provider: Read-only network connection (RpcProvider)
• Account: Extends Provider with signing and transaction capabilities
• Contract: Type-safe interface to deployed contracts

Use Provider for read operations, Account for write operations.

Provider Setup

import { RpcProvider } from 'starknet';

// Recommended: Auto-detect RPC spec version
const provider = await RpcProvider.create({
  nodeUrl: 'https://rpc.starknet.lava.build'
});

Networks:

• Mainnet: https://rpc.starknet.lava.build
• Sepolia: https://rpc.starknet-testnet.lava.build

Key Methods:

const chainId = await provider.getChainId();
const block = await provider.getBlock('latest');
const nonce = await provider.getNonceForAddress(accountAddress);
await provider.waitForTransaction(txHash);

// Read storage directly
const value = await provider.getStorageAt(contractAddress, storageKey);

Account Management

Account Creation (4 Steps)

Step 1: Compute address

import { hash, ec, encode, CallData } from 'starknet';

// IMPORTANT: `stark.randomAddress()` returns an address-like random felt and is NOT a private key.
// Use a real stark curve private key generator.
const privateKey = '0x' + encode.buf2hex(ec.starkCurve.utils.randomPrivateKey());
const publicKey = ec.starkCurve.getStarkKey(privateKey);

// NOTE: account class hashes are network/account-type dependent.
// Treat this as an example only (verify the correct class hash for your setup).
const classHash = '0x540d7f5ec7ecf317e68d48564934cb99259781b1ee3cedbbc37ec5337f8e688'; // example

const constructorCalldata = CallData.compile({ publicKey });
const address = hash.calculateContractAddressFromHash(publicKey, classHash, constructorCalldata, 0);