Executive summary

Trézór Bridge is designed as a secure bridge between your physical hardware wallet and the modern web. Browsers intentionally limit direct hardware access to protect users; Bridge provides a controlled, local proxy that enables secure communication without exposing keys or sensitive data to the web. This document explains Bridge's features, installation, security model, developer integration, troubleshooting, and maintenance — providing everything users, integrators, and developers need to adopt it confidently.

Why Bridge? The problem it solves

As the crypto ecosystem moved toward browser-based interfaces and decentralized applications, two problems emerged: fragmented USB support across browsers and security risks when sites attempt to access hardware. Browsers are sandboxed for a reason — direct USB access from any site could allow malicious actors to enumerate and interact with devices. Trézór Bridge offers a safer approach: a locally running, auditable service that only accepts requests from approved origins and always requires explicit user confirmation on the hardware device for signing operations.

Design principles

Key features & capabilities

• Cross-platform installers: Windows, macOS, and Linux packages with clear checksums and code signing to verify authenticity.
• Browser compatibility: Works with Chrome, Edge, Firefox, and other modern browsers that support WebUSB/WebHID or can proxy requests through Bridge.
• Origin whitelisting and permissioning: Sites must request access; users can grant one-time or persistent permissions via a clear UI.
• Background service with manual control: Bridge can run on startup for convenience or be launched manually for tighter control.
• Developer tools: optional debug mode, connection traces, and SDK support to simplify building secure integrations.
• Multiple device handling: Support for connecting and managing more than one Trezór device simultaneously when necessary.

Installation & quick start

Security reminder: Only download installers from the official trezor.io domain and verify file checksums or digital signatures if operating in a high-risk environment.

1. Download: Select the installer for your OS (Windows .exe, macOS .dmg/.pkg, Linux .deb/.AppImage or distribution package).
2. Install: Run the installer. On Windows, administrative rights may be required to register a system service; on macOS, approve the app in the Applications folder; on Linux, ensure udev rules are deployed to allow non-root USB access.
3. Launch: After installation, open the Bridge app or let the service run in the background. Optionally configure auto-start behavior.
4. Connect: Attach your Trezór device with a data-capable USB cable and open your web wallet or dApp. The site will request permission — review the origin and requested actions, then authorize as appropriate.

// macOS: manual launch if not auto-started
open /Applications/Trezor\ Bridge.app

// Linux: reload udev rules after installing
sudo udevadm control --reload-rules && sudo udevadm trigger

Permissions & UX model

Bridge implements a transparent permissions model designed to help users make informed choices:

• One-time Authorization: Access is granted only for the current session and revoked when the site or tab is closed.
• Persistent Authorization: Trusted sites can be granted longer-lived access; these entries appear in the Bridge privacy hub and can be revoked anytime.
• Minimal metadata exposure: Web apps receive only the information necessary to perform the requested action (e.g., public addresses, transaction details) and never private keys.
• User confirmation on device: Critical signing actions require confirmation on the hardware display to ensure the user explicitly approves each operation.

Security architecture

Bridge sits between the browser and the device and is designed to minimize attack surface. At a high level:

1. Web application requests a connection via a secure local API served by Bridge.
2. Bridge validates the requesting origin against its permission store and prompts the user with clear details.
3. If authorized, Bridge forwards the sanitized request to the Trezór device using an authenticated channel.
4. The device displays transaction or operation details and asks for physical confirmation on the device screen before signing.
5. Signed payloads return to the web app via Bridge — private keys never leave the device.

Developer integration

Developers should integrate using the official Trezór Connect SDK and follow secure patterns:

• Always validate origin server-side and client-side when appropriate.
• Present clear UX around transaction details before calling sign operations.
• Support graceful handling of user-denied permissions and device disconnects.
• Use the debug logs only for local troubleshooting and avoid sending logs containing device metadata to remote servers without user consent.

// Example: detect the Trezór Connect global and fetch features
if (window.TrezorConnect) {
  TrezorConnect.getFeatures()
    .then(res => console.log('Device features', res))
    .catch(err => console.error('TrezorConnect error', err));
}

Troubleshooting — detailed

Below are common issues and step-by-step actions to resolve them. Start with the simplest checks and move toward more advanced diagnostics as needed.

Connection fails to appear in browser

• Verify Bridge is running — check system tray/menu bar or run the process list.
• Try a different USB cable and port; avoid USB hubs and docking stations when possible.
• Temporarily disable privacy or firewall software that might block local ports or interprocess requests.
• Restart both the Bridge service and your browser.

Device detected but transactions fail

• Confirm firmware on the device is up to date; outdated firmware can cause compatibility errors.
• Inspect the transaction preview on the device; errors often occur when a value or destination is malformed.
• Enable debug logs in Bridge and capture the error trace to share (without the recovery seed or private key).

Linux-specific problems

• Ensure udev rules are installed and match the Trezór vendor/product IDs.
• Reload udev rules and reconnect the device, or log out and back in to apply permission changes.

Logs, telemetry, and privacy

Bridge aims to avoid unnecessary telemetry by default. The app may offer opt-in diagnostics to help developers and support teams; however, logs are designed to exclude secrets. When enabling diagnostics, users should review what will be captured and only share logs with trusted support representatives.

Release & update strategy

Security and compatibility are ongoing concerns; Bridge follows a release cadence that prioritizes critical security fixes and cross-browser compatibility patches. Users can choose automatic updates for convenience or manual updates for tighter control. Release notes accompany every update to explain changes, fixes, and migration steps if needed.

Best practices for users

• Always download software from the official site and verify checksums or signatures in high-risk situations.
• Keep operating system, browser, Bridge, and device firmware up to date.
• Store your recovery seed offline and never enter it into a computer or website.
• Use one-time permissions for unfamiliar websites and reserve persistent permissions for trusted services only.
• Regularly review the privacy hub/revocation list and remove unused authorizations.

Advanced topics

Running Bridge in air-gapped workflows

While Bridge is designed for internet-connected setups, advanced users running air-gapped workflows can still benefit from Bridge to manage local interactions without exposing keys. In these scenarios, avoid enabling optional cloud telemetry, and keep any Bridge logs local.

Interoperability with other wallet software

Bridge is intentionally interoperable — it is designed to work with any web wallet or dApp that follows the Trezór Connect patterns. When integrating other wallet software, ensure they clearly surface transaction details and request only necessary permissions.

FAQ

Do I need Bridge if I use the Trézór desktop app?

No. The desktop Trézór Suite communicates directly with hardware devices and does not require Bridge. Bridge is intended for browser-based interactions and third-party web apps.

Is Bridge safe to run all the time?

Yes — Bridge is a lightweight background service designed to accept only local connections from trusted origins and to prompt the user for all sensitive actions. If you prefer, you can disable auto-start and run Bridge only when needed.

Can a website steal my private keys via Bridge?

No. Bridge forwards requests but never exposes private keys. The device itself performs signing and other sensitive operations. Always verify transaction data on your device before approving.

What should I do if I suspect malicious activity?

Immediately revoke website permissions from the Bridge privacy hub, disconnect the device, and check for unauthorized transactions. Contact official Trézór support and share logs if instructed; never share your recovery seed.

Support & community

For step-by-step troubleshooting, user guides, and community help, consult the official Trézór documentation and community forums. For security incidents, reach out to official support channels and follow their guidance.

Appendix: example commands & checks

// macOS: check Bridge process
ps aux | grep -i trezor\ bridge

// Windows (PowerShell): view service status
Get-Service -Name "TrezorBridge*"

// Linux: view udev rules
cat /etc/udev/rules.d/99-trezor.rules

End of guide.