Trezor Bridge — Secure Your Hardware Wallet®

What is Trezor Bridge?

Trezor Bridge is a small background application that enables secure communication between your Trezor hardware wallet and desktop web applications or the Trezor Suite. It handles USB/communication protocols, provides a consistent API surface for browsers and native apps, and isolates device communication away from the browser environment to reduce attack surface. Bridge is designed to be lightweight and is updated periodically to support new firmware features, platforms, and security patches.

Why Bridge matters

Modern web browsers intentionally restrict low-level USB access for security reasons. Trezor Bridge acts as a trusted local intermediary that safely exposes a controlled interface for Trezor devices while minimizing the possibilities for unauthorized access by malicious web pages or software. By using Bridge, Trezor maintains a separation between untrusted web content and the sensitive device interactions that must be confirmed on the hardware screen.

Key features

• Cross-platform compatibility: Works on Windows, macOS, and Linux and provides a consistent experience to Suite and supported web apps.
• Secure transport: Uses local, authenticated channels to forward requests to the hardware device; requires user confirmation on-device for critical actions.
• Automatic updates: When enabled, Bridge can self-update to ensure the latest protocol and security fixes are applied.
• Developer-friendly API: Provides a stable interface for application developers to integrate Trezor devices into wallets, dApps, and tooling.

Install & update — quick guide

Installing Bridge is straightforward. Follow these steps depending on your platform.

Security considerations

Trezor Bridge is critical to your device security model. Use the following recommendations to minimize risk.

Source and authenticity

Only obtain Bridge from the official vendor site. Check digital signatures or checksums where provided. Avoid third-party downloads, package mirrors of unknown provenance, or links from social media that may be tampered with.

Least privilege

Bridge runs with minimal privileges required to access USB devices. On some systems you may be prompted to grant permission for USB access; review these prompts carefully and avoid granting persistent access to untrusted applications.

Local-only communication

Bridge communicates locally — it does not forward your recovery seed or private keys over the network. Sensitive operations still require explicit user approval on the hardware device. Treat the Bridge local web UI and any endpoints as potentially sensitive: avoid exposing them to remote networks or port forwarding.

Compromise scenarios

If your operating system is compromised by malware, local applications (including Bridge) could be manipulated. However, critical protections remain: the Trezor device will still display transaction details and require on-device confirmation, which prevents silent theft without user consent. That said, malware can attempt to trick you — always verify transaction data on the device screen and avoid authorizing unexpected transactions.

Troubleshooting

• Bridge not found: Ensure Bridge is installed and running. Restart the Bridge service and the Trezor Suite. Check for multiple Bridge instances or conflicting software that may claim USB devices.
• Device not detected: Try a different USB cable and port, and avoid USB hubs if possible. On Linux, confirm udev rules are installed so non-root users can access USB devices. Rebooting the system can resolve persistent USB driver issues.
• Bridge errors in browser: Clear browser caches and confirm that local endpoints (127.0.0.1) are accessible. Some corporate networks or security tools may block local loopback traffic — whitelist Bridge where required.
• Update failures: If automatic updates fail, download the latest installer manually from the official site and reinstall. Backup any important configuration before reinstallation if necessary.

Developer notes & integration

Developers building wallets, browser extensions, or dApp integrations will typically interface with Bridge through well-defined APIs and libraries. Respect the security model: never request a user’s recovery seed, and design UX flows that prompt the user to verify all critical transaction details on their Trezor device. Libraries exist to simplify common flows (enumeration, connecting, signing transactions), but always use maintained official libraries where possible.

Best practices for app developers

• Audit dependencies: Use audited, up-to-date libraries and perform code reviews for crypto and USB handling code.
• Fail-safe UX: Provide clear instructions and fail-safes when Bridge or the device is unavailable; never assume silent approval.
• Limit permissions: Request only the permissions you need and avoid long-lived or overly broad access tokens to local endpoints.
• Test across platforms: Validate behavior on Windows, macOS, and Linux, including different USB stacks and permission models.

Privacy

Bridge itself does not collect your private keys or seeds. It may, however, provide diagnostic information in logs to help with troubleshooting. Be mindful of any logs that may include transaction metadata; secure logs and clear them if necessary. When seeking support, avoid sharing seeds or private keys — instead share sanitized logs or device fingerprints that help troubleshoot without compromising security.

Enterprise deployment

Organizations deploying Trezor devices at scale may want to manage Bridge installation and updates centrally. Consider the following:

• Signed installers: Host verified installers on internal mirrors and verify cryptographic signatures before deployment.
• Controlled updates: Test Bridge updates on staging environments before rolling them out to production machines managing funds.
• Access control: Use role-based access and endpoint protection to limit which systems can interact with hardware wallets.

Release & support

Bridge releases accompany device and Suite updates. Subscribe to official release notes and changelogs for security advisories and feature announcements. If you encounter unusual behavior or potential security issues, report them to official support channels — avoid publicly posting seeds or detailed diagnostic info that could be abused.

FAQ

Checklist — before you connect

• Download Bridge from the official site — verify URL and checksum.
• Install and start Bridge; confirm the local status page is reachable.
• Connect your Trezor device directly (avoid hubs) and confirm on-device prompts.
• Verify Suite or your web app prompts correspond exactly to your on-device confirmations.