Client Libraries

Official client libraries are available for Python, PHP, JavaScript, and Swift. All libraries communicate with a VIZ node over the JSON-RPC API and handle transaction signing locally.

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Python — viz-python-lib

Repository: https://github.com/VIZ-Blockchain/viz-python-lib

Installation

pip install viz-python-lib

Quick start

from viz import Client

viz = Client(
    node="wss://node.viz.cx/ws",
    keys=["5...private_key..."]
)

# Award energy to an account
viz.award("receiver_account", 10.5, "with love", None, "your_account")

Features

• WebSocket (wss://) and HTTP (https://) transport
• Full transaction broadcasting: all protocol operations
• Local key management — private keys never leave the client
• Automatic retry and failover across multiple nodes
• Python 3 compatible

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PHP — viz-php-lib

Repository: https://github.com/VIZ-Blockchain/viz-php-lib

Installation

The library uses PSR-4 autoloading and does not require Composer. Clone or download the repository and include the autoloader:

require_once '/path/to/viz-php-lib/autoload.php';

PHP extension requirements: gmp (preferred) or bcmath for big-integer arithmetic.

Quick start

$private_key = '5...your_private_key...';
$tx = new VIZ\Transaction('https://api.viz.world/', $private_key);

// Build and broadcast an award transaction
$tx_data   = $tx->award($account, 'committee', 1000, 0, 'memo');
$tx_status = $tx->execute($tx_data['json']);

Features

• All 40 protocol operations supported
• AES-256-CBC memo encryption/decryption
• No external dependencies — standard PHP extensions only
• Compatible with PHP 7.x and 8.x

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JavaScript — viz-js-lib

Repository: https://github.com/VIZ-Blockchain/viz-js-libnpm: https://www.npmjs.com/package/viz-js-lib

Installation

npm install viz-js-lib --save

CDN (browser)

<!-- jsDelivr -->
<script src="https://cdn.jsdelivr.net/npm/viz-js-lib/dist/viz.min.js"></script>

<!-- Unpkg -->
<script src="https://unpkg.com/viz-js-lib/dist/viz.min.js"></script>

Quick start

const viz = require('viz-js-lib');

// Derive WIF key from credentials
var wif = viz.auth.toWif(username, password, 'regular');

// Broadcast a vote
viz.broadcast.vote(wif, voter, author, permlink, weight, function(err, result) {
    console.log(err, result);
});

Node configuration

viz.config.set('websocket', 'wss://node.viz.cx/ws');
// or HTTP:
viz.config.set('websocket', 'https://node.viz.cx/');

Features

• WebSocket (ws:// / wss://) and HTTP (http:// / https://) transports
• Works in Node.js and modern browsers
• Key utilities: toWif, toPublic, isWif, signTransaction
• Full broadcast API covering all protocol operations
• MIT license

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Swift — viz-swift-lib

Repository: https://github.com/VIZ-Blockchain/viz-swift-lib

Low-level, unopinionated Swift library providing primitives — operations, transactions, signing, JSON-RPC — without hiding any details. Suitable for mobile wallets, backend services, and bots where full control is required.

Installation

Swift Package Manager — add to Package.swift:

dependencies: [
    .package(
        url: "https://github.com/viz-blockchain/viz-swift-lib.git",
        .upToNextMinor(from: "0.1.0")
    )
]

Or in Xcode: File → Add Packages… and enter the repository URL.

Quick start

import VIZ

let client = VIZ.Client(address: URL(string: "https://node.viz.cx")!)

// Fetch chain head for the reference block
let props = try await client.send(VIZ.API.GetDynamicGlobalProperties())

// Derive the signing key
let key = VIZ.PrivateKey(seed: "alice" + "active" + "password")!

// Build the operation
let transfer = VIZ.Operation.Transfer(
    from: "alice",
    to: "bob",
    amount: VIZ.Asset(10.0, .viz),
    memo: "Thanks!"
)

// Wrap in a transaction, sign, and broadcast
let tx = VIZ.Transaction(
    refBlockNum: UInt16(props.headBlockNumber & 0xFFFF),
    refBlockPrefix: props.headBlockId.prefix,
    expiration: props.time.addingTimeInterval(60),
    operations: [transfer]
)
let signed = try tx.sign(usingKey: key)
let confirmation = try await client.send(
    VIZ.API.BroadcastTransaction(transaction: signed)
)

Key utilities

// Derive keys from seed
let privateKey = VIZ.PrivateKey(seed: "username" + "active" + "password")!
let publicKey  = privateKey.createPublic()
print(publicKey.address)  // VIZ7…
print(privateKey.wif)     // 5K…

// Import from WIF
let imported = VIZ.PrivateKey("5KQwrPbwdL6PhXujxW37FSSQZ1JiwsST4cqQzDeyXtP79zkvFD3")!

// Assets
let amount = VIZ.Asset(100.5, .viz)    // "100.500 VIZ"
let shares = VIZ.Asset(1000.0, .vests) // "1000.000000 VESTS"

Features

• Full operation coverage: transfers, awards, account create/update, vesting, escrow, recovery, and more
• Composable transactions — multiple operations in one signed transaction
• Pure-Swift secp256k1 ECDSA signing; key derivation from seed; WIF import/export
• async/await JSON-RPC client with actor-based concurrency, Sendable types throughout
• Multi-signature authority composition
• Delegated signing via viz:// URLs
• Cross-platform: iOS 13+, macOS 10.15+, tvOS 13+, watchOS 6+, Linux
• No hidden state — key management, retries, and broadcasting are left to the caller
• MIT license

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Choosing a Library

Criterion	Python	PHP	JavaScript	Swift
Install	pip	Manual PSR-4	npm / CDN	Swift PM / Xcode
Transport	WS / HTTP	HTTP	WS / HTTP	HTTP (async/await)
Runtime	Python 3	PHP 7+	Node.js / browser	iOS / macOS / Linux
Dependencies	minimal	GMP or BCMath	none (bundled)	secp256k1, OrderedDictionary
Level	high-level	high-level	high-level	low-level primitives
License	MIT	MIT	MIT	MIT

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See also: JSON-RPC API, CLI Wallet.