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).
Security Considerations
Trezor Bridge is intentionally narrow in scope — it is not a wallet and does not hold secrets. Security depends on multiple layers:
- Device security: Keys remain inside the Trezor hardware and are only released via signed responses after on-device confirmation.
- Local host security: Bridge runs locally; keep your OS and software updated to reduce the risk of local exploitors intercepting traffic.
- 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.