Qtum Wallet Snap

What Is the Qtum Wallet Snap?

The Qtum Wallet Snap is an extension that lives inside MetaMask and acts as an RPC proxy between your dApp and the Qtum blockchain. From a developer's perspective, it looks just like calling MetaMask — you use window.ethereum.request with wallet_invokeSnap, and the Snap forwards the request to a Qtum node using the Qtum ethers adapter.

From a user's perspective, it means you don't need a separate wallet to interact with Qtum. Your Qtum private key is derived from the same MetaMask seed phrase you already have, using the standard BIP32 path m/44'/88' — the registered Qtum coin type. The Snap or the Qtum team never see your keys.

What You Can Do With It

How It Works

The Snap sits between your dApp and the Qtum network. Calls go through MetaMask, are handled by the Snap's sandboxed JavaScript code, and are forwarded to a Qtum RPC node using the Qtum ethers adapter. Transactions are signed locally inside the Snap and never leave MetaMask in plaintext.

The connect flow

Install & Use

For users

Visit any dApp that integrates the Snap (such as the Qtum Dice or Lucky Spin demos), click Connect Wallet, and approve the Snap install prompt in MetaMask. You can also install it directly from the MetaMask Snaps Directory.

For developers

The Snap is published on npm as qtum-wallet. To request it from a dApp:

const SNAP_ID = 'npm:qtum-wallet';

// 1. Ask MetaMask to install / enable the Snap
await window.ethereum.request({
  method: 'wallet_requestSnaps',
  params: { [SNAP_ID]: {} },
});

// 2. Get the user's Qtum address
const address = await window.ethereum.request({
  method: 'wallet_invokeSnap',
  params: {
    snapId: SNAP_ID,
    request: { method: 'wallet_getAddress' },
  },
});

// 3. Read the balance
const balanceHex = await window.ethereum.request({
  method: 'wallet_invokeSnap',
  params: {
    snapId: SNAP_ID,
    request: {
      method: 'eth_getBalance',
      params: [address, 'latest'],
    },
  },
});

A complete React integration — including QTUM-specific gotchas like base58 ↔ hex address conversion, satoshi-based unit math (Qtum uses 8 decimals, not 18), and ABI encoding for contract calls — is documented in the Snap Integration Guide.

Supported RPC Methods

The Snap implements the MetaMask JSON-RPC API surface that makes sense for Qtum, plus a few wallet-management helpers. All of these are invoked through wallet_invokeSnap.

Wallet management

Reading from the chain

Signing & sending

Security & Trust Model

Audited

The Qtum Wallet Snap was audited by Sayfer, a Consensys-approved auditor, and went through Consensys' Snap review process before being listed in the MetaMask Snaps Directory.

Non-custodial & sandboxed

The Snap runs inside MetaMask's secure sandbox, communicates only through MetaMask's JSON-RPC bridge, and never exposes your private key to dApps or to the network. Keys are derived from your MetaMask seed phrase using BIP32 path m/44'/88', so the same recovery phrase that backs up your Ethereum accounts also backs up your Qtum account. Neither the Qtum team nor MetaMask can access your wallet.

Permissions requested

See It in Action

Two reference dApps demonstrate end-to-end use of the Snap, with full source and documentation:

Resources

• npm package: npmjs.com/package/@qtumproject/qtum-wallet
• MetaMask Directory: snaps.metamask.io — Qtum Wallet
• Source code: github.com/qtumproject/qtum-extension-wallet
• Qtum docs: docs.qtum.site
• Community: Qtum Discord · [email protected]