w3wallets

Web3 wallets for Playwright.

This library provides methods for interacting with Web3 wallets using Playwright.

npm install -D w3wallets

Getting Started

MetaMask and Polkadot{.js} wallets are currently supported.

1. Download wallets

npx w3wallets metamask polkadotjs

Short aliases are also supported:

npx w3wallets mm pjs

The unzipped files are stored in the .w3wallets/<wallet-name> directory. Add .w3wallets to .gitignore.

CLI Options

USAGE:
  npx w3wallets [OPTIONS] <targets...>

TARGETS:
  Alias name      Known wallet alias (metamask, polkadotjs)
  Short alias     Short form (mm, pjs)
  Extension ID    32-character Chrome extension ID
  URL             Chrome Web Store URL

OPTIONS:
  -h, --help      Show help message
  -l, --list      List available wallet aliases
  -o, --output    Output directory (default: .w3wallets)
  -f, --force     Force re-download even if already exists
  --debug         Save raw .crx file for debugging

EXAMPLES:
  npx w3wallets metamask                    # Download MetaMask
  npx w3wallets mm pjs                      # Download all wallets (short)
  npx w3wallets --list                      # List available aliases
  npx w3wallets -o ./extensions metamask    # Custom output directory
  npx w3wallets --force mm                  # Force re-download

2. Wrap your fixture with withWallets

Install the required wallets into Chromium using withWallets.

// your-fixture.ts
import { withWallets, metamask, polkadotJS } from "w3wallets";
import { test as base } from "@playwright/test";

export const test = withWallets(base, metamask, polkadotJS);

export { expect } from "@playwright/test";

3. Use the installed wallets in tests

Most commonly, you will use the following methods:

1. onboard: to set up your wallet
2. approve: for operations that confirm actions
3. deny: for actions that reject or cancel operations

import { test, expect } from "./your-fixture";

test("Can connect MetaMask to dApp", async ({ page, metamask }) => {
  const mnemonic =
    "set your seed phrase test test test test test test test junk";

  await metamask.onboard(mnemonic);
  await page.goto("https://your-dapp.com");

  await page.getByRole("button", { name: "Connect Wallet" }).click();
  await metamask.approve();

  await expect(page.getByText("Connected")).toBeVisible();
});

Caching

Wallet onboarding can be slow. Caching lets you run the setup once and reuse the browser profile across tests.

1. Create a setup file

Create a *.cache.ts file in a wallets-cache/ directory (default):

// wallets-cache/default.cache.ts
import { prepareWallet, metamask } from "w3wallets";

export default prepareWallet(metamask, async (wallet, page) => {
  await wallet.onboard("your seed phrase ...", "YourPassword123!");
});

2. Build the cache

npx w3wallets cache

CLI Options

USAGE:
  npx w3wallets cache [OPTIONS] [directory]

OPTIONS:
  -f, --force   Force rebuild even if cache exists
  --headed      Run browser in headed mode
  directory     Directory containing *.cache.{ts,js} files (default: ./wallets-cache/)

The cached profiles are stored in .w3wallets/cache/. The .w3wallets directory should already be in .gitignore.

3. Use cached wallets in tests

Import the setup and pass it to withWallets:

import { test as base, expect } from "@playwright/test";
import { withWallets } from "w3wallets";
import cachedMetamask from "./wallets-cache/default.cache";

const test = withWallets(base, cachedMetamask);

test("wallet is ready", async ({ metamask }) => {
  await metamask.unlock("YourPassword123!");
  // wallet is already onboarded
});

Note: All wallets in a test must be either all cached or all non-cached.

Configuration

Configure library behavior via environment variables:

Variable	Description	Default
W3WALLETS_ACTION_TIMEOUT	Timeout (ms) for all wallet actions (click, fill, navigation, assertions)	undefined

Example:

# In .env or CI environment
W3WALLETS_ACTION_TIMEOUT=60000

This only affects w3wallets library code. Your own Playwright configuration remains independent.