# Browser Extension

The KeepKey browser extension lets any EVM dapp treat your hardware wallet like a hot wallet. If a website understands `window.ethereum` — Uniswap, OpenSea, Farcaster frames, Lens, any MetaMask-compatible dapp — it understands the extension, with no extra integration work on the dapp's side.

<img src="/en/images/browser-extension/promobig.png" alt="KeepKey browser extension promo" style={{ width: '100%', borderRadius: '8px', margin: '16px 0' }} />

## Why use the extension

- **Hardware-grade security in your browser.** Private keys never leave the device. Every signature is verified on the KeepKey screen before it's released.
- **One-click dapp connectivity.** Uniswap, OpenSea, Curve, Aave, 1inch, and thousands of other EVM dapps connect instantly.
- **Multi-chain.** Ethereum, Polygon, Arbitrum, Optimism, Base, BNB Chain, Avalanche — automatic network switching via the standard `wallet_switchEthereumChain` RPC.
- **Familiar UX.** The interface follows MetaMask conventions, so if you've used MetaMask you already know how it works. The difference is that every signature goes to your KeepKey.

## How it works

The extension injects the standard `window.ethereum` provider into every web page, which is the interface dapps use to request accounts and signatures. When a dapp calls `eth_requestAccounts` or `eth_sendTransaction`, the extension forwards the request to the KeepKey desktop application over the local REST API, which in turn asks your device to approve.

<img src="/en/images/browser-extension/keepkey-bex-uni.png" alt="KeepKey extension connected to Uniswap" style={{ width: '100%', borderRadius: '8px', margin: '16px 0' }} />

From the dapp's perspective, you're just another Web3 wallet. From your perspective, every signature goes through the hardware device.

## Requirements

The extension is available for **Chrome only**. It requires the KeepKey desktop application to be running with the **API bridge enabled**. The extension talks to the desktop app over `http://localhost:1646`, which in turn talks to the device.

1. [Install the desktop application](/docs/desktop/install)
2. Open **Settings → API Servers** and enable the API bridge
3. Install the Chrome extension from [keepkey.com/keepkey-browser-extension](https://keepkey.com/keepkey-browser-extension)
4. On first use, approve the extension's pairing request in the desktop app

See [Settings → API Servers](/docs/desktop/settings#api-servers) for why the API bridge is off by default and when to enable it.

## Home dashboard

The extension's popup shows your balances, recent activity, and network selection at a glance.

<img src="/en/images/browser-extension/bex-home.png" alt="Extension home dashboard" style={{ width: '100%', borderRadius: '8px', margin: '16px 0' }} />

## Supported chains

<img src="/en/images/browser-extension/bex-blockchains.png" alt="Supported blockchains" style={{ width: '100%', borderRadius: '8px', margin: '16px 0' }} />

The extension supports all major EVM networks and bridges automatically when a dapp requests a chain switch.

## Featured dapp integrations

<img src="/en/images/browser-extension/bex-dapps.png" alt="Popular dapps tested with the extension" style={{ width: '100%', borderRadius: '8px', margin: '16px 0' }} />

We regularly test the extension against popular EVM dapps. If you find one that doesn't work, [open an issue](https://github.com/keepkey/keepkey-vault/issues) and let us know.

## Security reminders

- **Always verify the dapp URL** before approving any signature. A malicious site can look identical to a real one.
- **Verify transaction details on the device.** The extension shows you a summary, but the device is the source of truth. Read [Verifying Transactions](/docs/desktop/verify-on-device).
- **Be careful with token approvals.** Granting "unlimited" allowance to a contract is the most common way people lose funds to bad contracts. Prefer specific amounts when you can.
- **Revoke extension access you don't need.** You can disconnect the extension from the desktop application's **Settings → API Servers** panel at any time.

## Related

- [Agent Mode (MCP)](/docs/bex/mcp) — let an AI agent inspect and drive the extension over the Model Context Protocol
- [Desktop Application](/docs/desktop) — the companion app the extension relies on
- [Settings → API Servers](/docs/desktop/settings#api-servers) — the security model
- [Verifying Transactions](/docs/desktop/verify-on-device) — always verify on device