Trezor Bridge — Definitive Guide & Reference 🧭🔗

1) What is Trezor Bridge? 🧱

Trezor Bridge is a lightweight background service that lets your browser and desktop apps talk to your Trezor hardware wallet securely. Think of it as a private courier 🚚 carrying messages between your device and wallet interfaces without exposing secrets to the web page itself.

The Bridge listens on a local endpoint, relays USB/HID communications, enforces origin checks, and helps route requests like getting public keys, signing transactions, and managing sessions. Unlike an extension that lives inside the browser, the Bridge runs at the OS level, giving you broader compatibility and fewer browser-specific quirks 🧩.

2) Why you need it ✅

• 🔌 Device connectivity: Many wallets and apps rely on Bridge for stable USB communication.
• 🧭 Cross-browser support: Works with Chrome, Firefox, Brave, Edge, and others that may restrict raw USB APIs.
• 🔐 Security boundary: Keeps signing isolated on your Trezor — private keys never leave the device.
• ⚙️ Fewer driver headaches: Particularly useful on Windows where drivers can be finicky.
• 🧰 Dev tooling: Enables local development with libraries such as @trezor/connect.

3) Installation & Setup 🛠️

Verify it’s running 🔎

Open your wallet interface (e.g., Trezor Suite). If Bridge is detected, you’ll see your device connection status update in seconds ⏱️.

# macOS
launchctl list | grep -i trezor

# Linux (systemd)
systemctl --user status trezord

# Windows (PowerShell)
Get-Process | Where-Object {$_.ProcessName -like "*trezor*"}
          

# macOS
launchctl kickstart -k gui/$(id -u)/com.trezor.trezord

# Linux
systemctl --user restart trezord

# Windows (PowerShell as Admin)
Restart-Service -Name "Trezor Bridge" -Force
          

4) Connecting your device 🔗

1. Use the original cable or a high-quality data cable (avoid charge-only leads) 🔌.
2. Plug in your Trezor and unlock it with PIN. If prompted, allow the connection on device ✅.
3. Open your wallet app. Bridge should detect the device and show accounts within moments.
4. If you’re asked to update firmware, read notes first, then proceed if you recognize the origin 🧠.

Tip: USB hubs can cause flaky connections. If you see random disconnects, plug directly into your machine ⚡.

5) Troubleshooting 🧩

Common symptoms & quick fixes

• 🚫 “No device found” — Reconnect the cable, try a different port, and restart Bridge.
• 🌀 Endless “Waiting for Bridge” — Your firewall or endpoint protection may block local connections. Allowlist the Bridge process.
• 🔁 Random disconnects — Replace cable, avoid hubs, disable aggressive USB power-saving.
• 🧱 Browser can’t reach Bridge — Ensure you didn’t block the local endpoint in privacy tools or DNS filters.

OS-specific checks 🧪

Clean reinstall 🧼

1. Uninstall Bridge from your system.
2. Reboot (important to release drivers) 🔄.
3. Download fresh installer and reinstall. Test again.

When to escalate 🚨

If Bridge starts but your device never appears, test on a second computer. If it works there, your first environment is the culprit; otherwise, contact support and include logs and OS details 📝.

6) Security Best Practices 🔒

• ✅ Verify downloads: Only install Bridge from the official Trezor website. Bookmark it to avoid phishing 🎣.
• 🔑 PIN & passphrase hygiene: Enter secrets on the device screen only; never inside a web form.
• 🧿 Check prompts: Confirm the site/app requesting actions is the one you intended (look at the URL carefully).
• 🛡️ Keep firmware & Bridge updated: Updates frequently harden comms and fix bugs.
• 📵 No seed on keyboards: Recovery seed should never touch your computer — use device-guided recovery.

Remember: the Bridge facilitates communication; it cannot sign on your behalf. All sensitive approvals stay on your Trezor ✅.

7) Developer Reference 🧑‍💻

Building a wallet or tool? The typical stack uses @trezor/connect (JS) to talk to the Bridge. The library handles transport, permissions, and capability checks so you can focus on UX 🎨.

Quick start (Node/Browser) ⚡

// Install
npm install @trezor/connect

// Initialize in your app
import TrezorConnect from "@trezor/connect";

TrezorConnect.init({
  connectSrc: "https://connect.trezor.io/9/", // example: pick the supported major
  lazyLoad: true,
}).then(() => console.log("Trezor Connect ready!"));

// Example: get public key (xpub)
const res = await TrezorConnect.getPublicKey({
  path: "m/84'/0'/0'",
});
if (res.success) {
  console.log("XPUB:", res.payload.xpub);
} else {
  console.error(res.payload.error);
}
      

Local dev tips 🧑‍🔬

• Run a local HTTPS origin (self-signed is fine) to pass origin checks 🔏.
• Ensure the Bridge process is running before calling Connect.
• If you’re hot-reloading, debounce device calls to avoid stale sessions 🔁.

Common error patterns 🧨

// Transport is not defined
// → Bridge not running or blocked by policy

// Permissions not granted
// → User denied on device; surface a clear retry path

// Device disconnected during action
// → Cable/port issue; prompt to reconnect and resume
      

8) FAQ ❓

Does Bridge store my keys? 🔑

No. Private keys remain inside your Trezor. The Bridge only relays messages.

Do I need Bridge if WebUSB works? 🌐

Sometimes not, but Bridge increases compatibility across browsers and enterprise setups. It’s the most reliable path for many users.

Is it safe to keep Bridge running? 🧯

Yes, it’s designed to sit quietly in the background. Keep it updated like any security-adjacent component.

Can multiple apps use Bridge at once? 🤹

Generally one app talks to the device at a time. Close other wallet apps if you see contention warnings.

What logs are useful for support? 🗒️

OS version, Bridge version, browser version, connection steps tried, and any console errors from your wallet app.

One-page checklist ✅

• Install Bridge from the official site 🏁
• Verify it’s running (service/process check) 🔍
• Use a data-capable cable and direct USB port ⚡
• Approve prompts on your Trezor only 🖱️➡️📟
• Keep firmware + Bridge current 📦
• Troubleshoot with restart and clean reinstall if needed 🧼