Who this is for: Frontend and full-stack developers who want to integrate Sui into web apps, wallets, or dashboards without relying solely on the CLI.

Goal: By the end of this article, you’ll be able to:

Install and configure the Sui TypeScript SDK.

Connect to testnet and query blockchain data.

Execute transactions programmatically.

Handle gas, effects, and common SDK pitfalls.

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Part 1 — What the Sui TypeScript SDK Does

The Sui TypeScript SDK is your bridge between a browser/server app and the Sui network. It:

Connects to RPC nodes to read data (objects, events, balances).

Submits transactions (transfers, Move calls).

Works in Node.js and browser environments.

Powers many wallets and dApps in the Sui ecosystem.

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Part 2 — Prerequisites

Before you start, you’ll need:

Node.js ≥ 18

npm or yarn

A Sui wallet (e.g., Sui Wallet extension) for private key management.

Some testnet SUI (get from faucet via CLI or wallet).

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Part 3 — Installing the SDK

1. Create a new project:

mkdir sui-ts-demo && cd sui-ts-demo npm init -y

2. Install the SDK:

npm install @mysten/sui.js

3. (Optional) Install dotenv for managing environment variables:

npm install dotenv

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Part 4 — Connecting to the Network

index.js (or index.ts if using TypeScript):

import 'dotenv/config'; import { JsonRpcProvider, Connection } from '@mysten/sui.js';

// Create a connection to the Sui testnet const provider = new JsonRpcProvider( new Connection({ fullnode: 'https://fullnode.testnet.sui.io/' }) );

// Test connection: Get latest block info async function getLatestBlock() { const latest = await provider.getLatestCheckpointSequenceNumber(); console.log('Latest Checkpoint:', latest); }

getLatestBlock();

Run:

node index.js

If successful, you’ll see a checkpoint number — meaning your SDK can talk to the network.

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Part 5 — Querying Data

Example: Fetch your SUI balance.

const address = process.env.MY_ADDRESS; // set in .env const coins = await provider.getCoins({ owner: address, coinType: '0x2::sui::SUI' });

console.log('Your coins:', coins.data); console.log('Total balance:', coins.data.reduce((sum, c) => sum + BigInt(c.balance), 0n).toString());

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Part 6 — Sending a Transaction (Transfer SUI)

1) Import Keypair

If you’re storing your key locally (dev/test only — never expose production keys):

import { Ed25519Keypair, RawSigner } from '@mysten/sui.js';

const secretKey = process.env.SECRET_KEY_BASE64; // base64-encoded private key const keypair = Ed25519Keypair.fromSecretKey(Buffer.from(secretKey, 'base64')); const signer = new RawSigner(keypair, provider);

2) Build and Send

async function sendSui(recipient, amount) { const tx = await signer.paySui({ inputCoins: (await provider.getCoins({ owner: keypair.getPublicKey().toSuiAddress() })).data.map(c => c.coinObjectId), recipients: [recipient], amounts: [amount], // in MIST (1 SUI = 1_000_000_000 MIST) });

console.log('Transfer digest:', tx.digest); }

sendSui('0xRECIPIENT_ADDRESS', 1_000_000);

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Part 7 — Calling a Move Function If you’ve published a package (e.g., counter from Article 1):

async function incrementCounter(packageId, objectId, by) { const tx = await signer.executeMoveCall({ packageObjectId: packageId, module: 'counter', function: 'inc', typeArguments: [], arguments: [objectId, by], gasBudget: 20_000_000, });

console.log('Increment digest:', tx.digest); }

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Part 8 — Common Problems & Solutions

Problem	Cause	Fix
Invalid base64 string	Wrong key encoding	Ensure key is raw private key in base64
Insufficient gas	No testnet SUI or small coin selected	Use faucet & merge coins via CLI before SDK call
Transaction never confirms	Wrong RPC endpoint	Use official testnet/mainnet fullnode URLs
Type errors in TS	SDK version mismatch	Install latest @mysten/sui.js and match TS config

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Part 9 — Development Tips

1. Never hardcode keys in source — use .env.

2. Batch reads — provider supports queries for multiple objects in one call.

3. Use events — subscribe to specific events from your Move modules.

4. Test in localnet — Sui CLI can run a local network for integration testing.

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✅ You can now:

Connect to Sui from JavaScript/TypeScript.

Query balances and objects.

Send SUI and call Move functions programmatically.