Overview
What is Trezor Bridge?
Trezor Bridge is a lightweight local bridge application that enables secure communication between your Trezor hardware wallet and web-based or desktop wallet software (for example Trezor Suite or wallet.trezor.io). It runs on the host machine, listens to USB devices, and provides a controlled API for the browser or local apps to speak to your Trezor device without exposing low-level USB details.
Why it exists
Browsers cannot directly access many USB device protocols reliably across platforms, so Trezor Bridge fills that gap — giving a stable, cross-platform channel for transaction signing, device management, and firmware updates while keeping private keys safely inside the hardware device.
Quick takeaway
Trezor Bridge is not a wallet or a cloud service — it’s a local helper that makes your hardware wallet usable with modern apps while keeping the private keys offline on the device.
How it works
Architecture
The Bridge runs as a small native service on your computer and exposes a local REST/JSON-RPC endpoint (or integrates with the Trezor Suite through IPC) that the browser or Suite calls. When a user requests a signature, the Suite asks the Bridge to forward commands to the Trezor; the device displays the transaction details on its secure screen and only signs when the user confirms physically on the device.
Data flow (short)
- User initiates a transaction in Trezor Suite or a web app.
- The app sends a request to Trezor Bridge running locally.
- Bridge forwards the request to the hardware wallet over USB.
- The device prompts user confirmation on its secure display.
- After confirmation, the device signs and returns the signature via Bridge to the app.
Security considerations
Threat model
Trezor’s security model assumes the host computer may be compromised. The private key never leaves the device. Bridge only relays structured commands; actual signing happens on the device that requires physical confirmation. This separation significantly limits remote attack vectors.
Best practices
- Download Bridge only from official channels (verified website or official GitHub releases).
- Keep your device firmware and Trezor Suite up to date to receive security patches.
- Verify websites and avoid paste-in prompts from unknown sources — always confirm transaction details on the device display.
- Enable additional protections like passphrase/hidden wallets if you need deniability or compartmentalization.
What Bridge does NOT do
Bridge does not hold or manage keys, it does not have a backdoor, and it cannot sign transactions without the hardware device being present and a user confirming the action on the device.
Setup & installation
Download
Obtain the latest Bridge installer from Trezor’s official website or the official GitHub releases for your operating system (Windows, macOS, Linux). Follow on-screen install instructions and, where appropriate, approve system prompts for device access.
Permissions & platform notes
On macOS and Windows, Bridge may require permission to access USB devices and to run as an always-on background helper. On Linux you may need udev rules. Trezor provides guides for all major platforms to make this straightforward.
Troubleshooting & tips
Common issues
- Bridge not detected: Restart the Bridge service, replug the USB cable, try another USB port, and confirm you installed the correct Bridge binary.
- Browser access blocked: Close the browser, ensure Bridge is running, then reopen the wallet site. Some browsers need explicit permission or a native messaging host to be registered.
- Outdated Bridge: Update to the latest release — old versions can be incompatible with newer devices or Suite releases.
Advanced tip
For power users or IT teams deploying many devices, automate installs via MSI or package managers where possible, and pin approved Bridge release versions in your environment to control updates.
Closing & recommended resources
This presentation explained what Trezor Bridge is, how it keeps signing secure by isolating keys on the hardware device, and practical steps to install and troubleshoot. Use official sources for downloads and keep your tools updated to stay secure.
View official resources