What is Trezor Bridge?

Trezor Bridge is a small native application that runs on your computer and provides a secure local communication channel between Trezor hardware wallets and desktop or browser-based applications. Historically, web browsers did not always provide reliable USB access for hardware wallets; Bridge acts as a trusted intermediary that exposes a controlled, local endpoint to which Trezor Suite and compatible websites can connect. When installed, Bridge handles USB device enumeration, forwards requests to the Trezor device, and returns signed responses — while ensuring the device’s private keys remain isolated on the hardware.

Installing & Using Trezor Bridge

Installation is intentionally straightforward: download the official installer for your OS, run the installer, and follow prompts. Once running, Bridge listens on a local port (not publicly exposed) and waits for authorized applications to request access. Typical steps:

• Navigate to the official download page (always verify the domain).
• Select the correct installer for Windows, macOS, or Linux.
• Run the installer, grant the minimal permissions requested, and allow the service to start.
• Open Trezor Suite or a compatible web app — it will detect Bridge automatically and guide you through device connection.

When an app asks to connect, you will see a prompt in the application. The Trezor device will display transaction details and require physical confirmation before signing anything. Bridge does not hold keys and does not sign transactions — it merely brokers the data path between the app and the device.

Developer & Advanced Notes

For developers, Trezor Bridge exposes a local API that desktop apps and web clients can use. Typical integrations will:

• Detect the running Bridge process by probing a localhost port.
• Request device lists, open a session, and send APDU-style commands.
• Respect CORS and local origin policies enforced by the Bridge and the browser.

When building integrations, follow these guidelines:

• Always verify the application’s origin and present transparent UI to the user when requesting device access.
• Use the official Bridge development docs and SDKs; avoid reimplementing low-level protocols unless necessary.
• Handle common error states gracefully (device disconnected, Bridge not installed, insufficient permissions).

Troubleshooting tip: If your app cannot find a Trezor device, check that Bridge is running, try restarting the Bridge service, re-plug the device, and ensure no other application has exclusive access to USB. On Linux, check udev rules and permissions.

Security Considerations

Trezor Bridge is intentionally narrow in scope — it is not a wallet and does not hold secrets. Security depends on multiple layers:

1. Device security: Keys remain inside the Trezor hardware and are only released via signed responses after on-device confirmation.
2. Local host security: Bridge runs locally; keep your OS and software updated to reduce the risk of local exploitors intercepting traffic.
3. Software authenticity: Verify downloads and signatures. Using the official site is the primary defense against tampered installers.

FAQ & Common Questions

Q: Do I always need Bridge? A: Modern browsers support WebUSB, and many users can connect directly without Bridge. However, Bridge provides a reliable fallback and a consistent experience across operating systems and configurations.

Q: Does Bridge access my private keys? A: No. Bridge only relays messages. The private keys never leave the Trezor device, and signing always happens inside the hardware with a physical confirmation required.

Final Notes

Trezor Bridge fills a key role in the usability stack for hardware wallets: it simplifies connectivity while keeping the cryptographic trust anchored in the hardware. Whether you’re a daily user or a developer integrating hardware wallet support, understanding Bridge — how to install it, what it does, and how to troubleshoot it — will make your Trezor experience smoother and more secure. Start at the official source, verify installers, and let Bridge handle the bridging while your Trezor enforces the security rules.