Trezor Bridge

What Is Trezor Bridge?

Trezor Bridge is a small, trusted helper application that enables secure communication between your Trezor hardware wallet and supported web applications or browser-based wallets. It acts as a local intermediary, translating USB signals to HTTP/WebSocket requests that your browser can understand — while keeping your private keys safely on the device.

In many modern browsers, direct access via WebUSB or WebHID might work, but compatibility and reliability can vary. Bridge offers a consistent, stable fallback (and in many setups, the preferred method) so that your Trezor remains detectable and usable across platforms.

How It Works

Under the hood, Trezor Bridge listens on a local interface (e.g. `localhost`) on your computer. It mediates communication between the browser (or application) and your Trezor device over USB. The Bridge handles transport, session management, permissioning, and encryption so that applications don’t need to deal with low‑level USB complexities.

Here’s a simplified flow:

1. Browser/app sends a request (e.g. “get public key”, “prepare transaction”) to Bridge via HTTP/WebSocket.
2. Bridge forwards that request to the Trezor device over USB.
3. The Trezor device processes the request, using internal logic and private keys.
4. For critical actions (such as signing), the device prompts you to confirm on its screen.
5. The signed response is sent back through Bridge, and then to the browser/app.

Importantly: **the private keys never leave the Trezor device**. Bridge just passes messages. Your machine does not hold secrets.

Install & Setup Guide

Installing and configuring Trezor Bridge is straightforward. Below are the general steps across platforms. Always download from the official source to avoid phishing risk.

1. Download the installer from the official Trezor site (or through the Trezor Suite “Start” page). Choose the correct version for your operating system.
2. Run the installer and follow on‑screen prompts. On macOS, you may need to approve running software from an identified developer. On Linux, additional udev rules may need installation.
3. Restart browser or system if your browser was open during installation.
4. Connect your Trezor device via USB. The Bridge should detect it automatically.
5. Open Trezor Suite or supported web app. It will prompt to connect via Bridge. Approve in the UI and on the device.
6. Confirm operations on your device. Always verify that the transaction or data shown on the device matches your intent.
7. Keep Bridge updated. Newer versions improve compatibility, bug fixes, and security. Running the latest version is strongly recommended.

Some scenarios:

• Windows / macOS: Run the installer package and follow the wizard.
• Linux: Use the provided package or generic installer, then add udev rules so the Trezor device is accessible to your user. Reload rules or reboot if necessary.
• Updating: Run a newer installer; it replaces the current version without disrupting your wallet data.

Security & Privacy Design

Trezor Bridge is built with security-first architecture. Below are the key principles and safeguards that keep your crypto safe.

• Local-only communication: Bridge does not send your data to any remote server. It only listens on `localhost` and forwards messages locally.
• No key access: Bridge never accesses, reads, or stores private keys, seeds, or PINs. Those remain locked in the hardware device.
• Device confirmation required: Critical operations (signing, transaction approval) always require you to explicitly confirm on the hardware device display.
• Permission control: Only known, whitelisted applications may communicate via Bridge, and sessions are limited in scope.
• Signed updates: Bridge installers are cryptographically signed. You should verify the publisher’s signature or checksums when downloading updates.
• Minimal privileges: Bridge runs with only the privileges required to access USB devices, and avoids broad system APIs wherever possible.

“Your private keys never leave your hardware wallet — Bridge simply passes authenticated commands.”

Frequently Asked Questions

Do I always need Bridge?

Not always. Many modern browser + OS combinations support WebUSB or WebHID, allowing the browser to connect to your Trezor directly. But these paths can be flaky depending on browser version, policies, or OS restrictions. Bridge provides a more consistent fallback, especially on older setups or for greater compatibility.

Is Bridge open-source and auditable?

Yes. Key components are public and can be audited by third parties. This transparency helps maintain trust and security in the system.

Will installing Bridge risk my funds?

When downloaded from the official source, Bridge itself poses no threat. It cannot steal funds, because private key operations must be confirmed on your physical device. The main risk is installing a counterfeit version from a malicious site — always verify checksums or signatures.

What if Bridge doesn’t detect my device?

Here are common fixes:

• Try a different USB port or cable (prefer data-capable cables).
• Close and reopen your browser or the Trezor Suite.
• Restart or relaunch the Bridge service.
• Reinstall Bridge from official source.
• On Linux, verify udev rules are installed and loaded.
• Disable browser extensions that may block localhost or USB operations.

Will Bridge slow down my computer?

No — Bridge is lightweight and uses minimal system resources. It runs only in the background and only when needed.

How do I update or uninstall Bridge?

To update, run the latest installer from the official site; Bridge will upgrade itself. To uninstall, use your OS’s standard method (e.g. Control Panel on Windows, uninstall script on macOS, package manager removal on Linux). Uninstalling only removes the bridge service—it does not affect your wallet or seed phrase.