Overview — What is Trezor Bridge?

Trezor Bridge is a lightweight application that runs on your computer and facilitates secure communication between web-based cryptocurrency wallets (or desktop clients) and Trezor hardware wallets. It acts as a local proxy, translating web USB or native client requests into a secure IPC (inter-process communication) pipeline with the device. Bridge reduces the need for a browser to directly access USB hardware in a complex cross-platform way, improving reliability while maintaining strong security boundaries.

Core benefits

  • Compatibility: Works across major operating systems and browsers, removing friction for users.
  • Security: Keeps device-level interactions local and explicit — approvals happen on your Trezor device.
  • Reliability: Provides a stable API for web wallets so transaction flows are less likely to fail due to browser USB quirks.
  • Simplicity: One small install on your machine ensures your browser can connect to your Trezor reliably.

How Bridge works (simplified)

1. Local daemon

Bridge runs as a local background process and listens to requests from browser extensions or web pages. It exposes a controlled interface that only accepts authenticated calls from permitted origins.

2. Secure channel to device

When a web wallet initiates an action (sign, get address), Bridge forwards the request to the connected Trezor device. The device itself displays details and requires the user to confirm each sensitive action.

3. User confirmations

Critical actions require manual confirmation on the device's screen — this separates ownership from the potentially compromised host machine.

4. Return path

Bridge collects the signed response from the device and passes it back to the requesting web page or client. The private keys never leave the hardware device.

Installation & quick checklist

  1. Download Bridge from the official Trezor website and verify HTTPS.
  2. Run the installer and allow Bridge to run as a background process.
  3. Connect your Trezor device via USB (or use appropriate OTG adapters for mobile where supported).
  4. Open your web wallet and grant connection when prompted. Confirm actions on your device.

Common troubleshooting scenarios

Issue: Browser cannot detect Trezor

Solution: Make sure Bridge is running. On Windows check the notification area; on macOS check the menu bar or Activity Monitor. Restart Bridge and your browser if necessary. Check USB cables and try a different port.

Issue: Permissions blocked

Solution: Some browsers may block automatic connections. Look for prompts and allow the origin, or consult the wallet's connection instructions. Temporarily disable strict privacy extensions that may interfere with local origin requests.

Issue: Bridge installer fails

Solution: Verify the installer checksum if available, run the installer with admin privileges, and consult logs. If the problem persists, open a support ticket with the system log and relevant screenshots.

Security considerations — what Bridge does NOT do

  • Bridge does not access or store your recovery seed or private keys.
  • Bridge is not a remote service; it runs locally on your machine and requires physical access to your device.
  • Bridge is not intended to be a substitute for device-level confirmations — all cryptographic approvals must be performed on the Trezor hardware.

Developer notes (for integrators)

For web wallet developers, Bridge exposes a clear API that can be used to enumerate connected devices, request public keys, and ask devices to sign transactions. When integrating, always respect origin checks and user prompts. Offer clear UI copy explaining that confirmations are required on the physical device — reinforce trust by showing device screens in your onboarding flow.

Sample terminal flow (mock)

$ trezorctl list
# Shows: /dev/ttyACM0 - Trezor Model T
$ trezorctl get-address --coin BTC
Requesting address on device...
Please confirm on your Trezor
Address: bc1q...abc123