Transactions are the fundamental building blocks of Arweave. Every file upload, every data write, every token transfer is a transaction. There are three main ways to post them: directly with Arweave JS, through the Turbo SDK bundler, or via browser dispatch.

Choosing a Method

Method	Best For	Max Size	Speed
Arweave JS	Full control, direct L1 transactions	No limit	Minutes (mining required)
Turbo SDK	Production apps, reliability, instant access	No limit	Instant (bundled)
Dispatch	Browser wallets, small uploads	100 KB	Instant (bundled)

Arweave JS

The official JavaScript SDK for interacting with the Arweave network directly.

Install

npm install arweave

Upload Data

import Arweave from 'arweave';

const arweave = Arweave.init({
  host: 'arweave.net',
  port: 443,
  protocol: 'https'
});

// Load your wallet
const wallet = JSON.parse(fs.readFileSync('wallet.json', 'utf-8'));

// Create a data transaction
const tx = await arweave.createTransaction({
  data: '<h1>Hello Permaweb</h1>'
}, wallet);

// Add tags for content type and discoverability
tx.addTag('Content-Type', 'text/html');
tx.addTag('App-Name', 'My-App');

// Sign and submit
await arweave.transactions.sign(tx, wallet);
const response = await arweave.transactions.post(tx);

console.log('Transaction ID:', tx.id);
console.log('View at:', `https://arweave.net/${tx.id}`);

Upload a File

import fs from 'fs';

const data = fs.readFileSync('photo.jpg');

const tx = await arweave.createTransaction({ data }, wallet);
tx.addTag('Content-Type', 'image/jpeg');

await arweave.transactions.sign(tx, wallet);
await arweave.transactions.post(tx);

Transaction Tags

Tags are key-value metadata attached to every transaction. They're how you organize, index, and query data on Arweave.

tx.addTag('Content-Type', 'text/html');  // MIME type for rendering
tx.addTag('App-Name', 'My-App');         // Your application identifier
tx.addTag('App-Version', '1.0.0');       // Version tracking
tx.addTag('Title', 'My Document');       // Human-readable title
tx.addTag('Unix-Time', String(Date.now() / 1000)); // Timestamp

Tags are Base64URL-encoded and limited to 2,048 bytes total per transaction.

Turbo SDK

ArDrive Turbo handles bundling, retries, and instant data availability. Recommended for production applications.

Install

npm install @ardrive/turbo-sdk

Upload with Turbo

import { TurboFactory } from '@ardrive/turbo-sdk';
import { ArweaveSigner } from '@ardrive/turbo-sdk/node';
import fs from 'fs';

// Load wallet and create signer
const jwk = JSON.parse(fs.readFileSync('wallet.json', 'utf-8'));
const signer = new ArweaveSigner(jwk);
const turbo = TurboFactory.authenticated({ signer });

// Upload a file
const filePath = './my-file.html';
const fileSize = fs.statSync(filePath).size;

const { id, owner, dataCaches, fastFinalityIndexes } = await turbo.uploadFile({
  fileStreamFactory: () => fs.createReadStream(filePath),
  fileSizeFactory: () => fileSize,
  signal: AbortSignal.timeout(60_000),
  dataItemOpts: {
    tags: [
      { name: 'Content-Type', value: 'text/html' },
      { name: 'App-Name', value: 'My-App' },
    ],
  },
});

console.log('Uploaded:', `https://arweave.net/${id}`);

Why Turbo?

• Instant availability: Transaction IDs are accessible immediately, no mining wait
• Reliability: Bundling services continuously retry posting, preventing dropped transactions
• Scale: A single bundle can hold up to 2^256 transactions
• Free tier: Uploads under 105 KiB are free via ArDrive Turbo

Dispatch

Browser wallets like Wander can dispatch small transactions (up to 100 KB) as bundled data items.

How It Works

// In a browser environment with a connected wallet
const tx = await arweave.createTransaction({
  data: 'Hello from the browser!'
});

tx.addTag('Content-Type', 'text/plain');
tx.addTag('App-Name', 'My-Browser-App');

// Dispatch instead of sign + post
const result = await window.arweaveWallet.dispatch(tx);

console.log('Dispatched:', result.id);

When to Use Dispatch

• Your users are interacting through a browser wallet
• The data is small (under 100 KB)
• You want instant settlement without managing server-side wallets

Checking Transaction Status

After posting, you can check whether a transaction has been confirmed:

const status = await arweave.transactions.getStatus(txId);
console.log('Status:', status.status);
// 200 = confirmed
// 202 = pending
// 404 = not found

For Turbo uploads, the data is available immediately through gateways even before onchain confirmation.