Overview
Trezor Bridge is an official, lightweight background application that acts as an intermediary between your Trezor hardware wallet and applications on your computer — most commonly the Trezor Suite web app, browser-based wallets, and developer tools. Its primary purpose is to provide a robust and secure channel for USB (or WebUSB) communication, handling permission prompts, device enumeration, and message routing so that web pages and applications do not need low-level USB access or platform-specific drivers.
How it works
When you plug in your Trezor device, Bridge detects the device using the platform's USB stack. It then exposes a local HTTP/WebSocket-like interface to authorized applications, allowing them to send commands and receive responses from the device. Importantly, Bridge does not have access to your private keys — all cryptographic operations and signing happen on the Trezor device itself. Bridge simply relays requests and responses.
Key features
- Local-only communication: Bridge listens on localhost and does not forward transactions or keys to remote servers.
- Cross-platform: Available for Windows, macOS, and Linux, packaged with installers appropriate for each OS.
- Auto-detection: Automatically detects connections and prompts compatible applications when a device is present.
- Secure permission flow: Gatekeeping to ensure only authorized browser tabs or apps can access your Trezor device.
- Automatic updates: Optionally checks for and installs updates to keep the Bridge secure and compatible.
Security model
Trezor Bridge is designed with the security principle of least privilege. It minimizes the attack surface by:
- Running as a local service with limited privileges.
- Requiring explicit user consent in the browser before a web page can talk to your device.
- Relaying raw messages to the device without exposing private keys — the Trezor device signs transactions internally and returns signatures to the calling application.
Installation & first run
Installation is straightforward. Download the Bridge installer for your platform and run the installer. On first run, Bridge will create a small background service and open a local helper page. When you connect your Trezor device and open a supporting web app or Trezor Suite, a browser permission prompt will appear asking you to authorize the connection. Approve the prompt and confirm any transactions directly on the device.
Developer integrations
Developers can integrate with Bridge using the documented JavaScript libraries provided by the Trezor team. Bridge exposes an API that client libraries use to discover devices, forward APDU commands, and receive responses. This makes it simple to build secure hardware-backed features into web wallets, exchanges, and DApps while keeping private key operations performed on-device.
Troubleshooting & common issues
Some common situations and how to address them:
- Device not found: Ensure Bridge is running, try reconnecting the device, and check that no other application is monopolizing the USB port.
- Permission prompt not appearing: Make sure your browser supports WebUSB and that you’re on an HTTPS site (web apps require secure context for USB access).
- Driver issues on older systems: Most modern OSes don't need extra drivers; on legacy systems a driver may be required — check the official documentation for platform-specific guidance.
Privacy & data handling
Bridge intentionally minimizes data collection. It does not transmit your wallet data, transaction details, or private keys to remote servers. Telemetry is minimal and opt-in; Bridge may collect anonymous version numbers or crash reports if you enable diagnostics, but this is optional and intended to improve reliability and security.
Best practices
- Always verify transaction details on the Trezor device before approving.
- Keep Bridge and your device firmware up to date to receive security patches and compatibility improvements.
- Use the official Bridge installer from the Trezor website to avoid tampered distributions.
- Run Bridge on a trusted machine and minimize running unknown browser extensions when using hardware wallets.
Compatibility & versions
Bridge supports the current Trezor models and is maintained to remain compatible with modern browser APIs. Release notes and compatibility matrices are published with each Bridge release so users and integrators can verify which versions are supported on their platform.
Enterprise & advanced deployment
For enterprise deployments, Bridge can be packaged and distributed internally with configuration to match corporate update channels. IT teams can control update behavior and monitor deployed versions across a fleet. Bridge is also useful in kiosk or controlled environments where explicit hardware wallet access is required by multiple local applications.
FAQ
Q: Does Bridge ever see my seed or private keys?
A: No — Bridge only relays messages. Private keys never leave the Trezor device and are not accessible to Bridge or applications.
Q: Can I use Bridge with headless servers?
A: Bridge is primarily a desktop/local tool. For headless or remote servers, other integration patterns such as using Trezor devices with a physically attached host or specialized USB-over-network solutions can be considered with caution.
Q: Is Bridge required to use Trezor devices?
A: Not always — some native apps can use direct HID access. However, Bridge provides the most reliable cross-platform experience especially for web-based applications.
Conclusion
Trezor Bridge plays an essential role in making hardware wallets accessible to modern browsers and native apps. By providing a secure, local communication layer, Bridge balances usability with the strong security guarantees of Trezor hardware. Whether you are an everyday user, developer, or enterprise admin, Bridge simplifies device connectivity while keeping your keys safe on the hardware.