Overview
Trezor Bridge is the official browser-to-device connector developed to let web applications talk to a Trezor hardware wallet through standard web interfaces. It serves as a secure bridge between USB/HTTP transport and browser-based wallets or dApps, enabling transaction signing, account management, and device firmware interactions without exposing private keys to the web.
Why Bridge?
Browsers restrict direct USB access for safety. Trezor Bridge runs locally and safely exposes a controlled API so that websites can request the device to perform cryptographic actions. It improves compatibility across browsers and operating systems.
Core responsibilities
- Device discovery and secure channel creation
- Message routing between browser apps and the Trezor device
- Version & firmware checks
How it works (technical flow)
A standard flow includes: the browser extension or web app sends a request → Bridge translates and forwards to the device over USB → the Trezor prompts the user on-device → user approves and the signed data returns back. This chain enforces user presence and prevents remote exfiltration of keys.
Transport & protocols
Trezor Bridge supports WebUSB (where available) and a local HTTP-to-USB proxy approach. All messages are serialised using protobufs or JSON-enveloped commands with signature verification on each critical step.
Security considerations
Security is central: the private keys never leave the Trezor. Always verify transaction details shown on the device display. The Bridge is intentionally minimal — it just transports requests and responses without interpreting or signing them itself.
Best practices
- Keep Bridge and device firmware up to date.
- Download Bridge only from official sources.
- Use an up-to-date browser and avoid unsigned third-party plugins.
- Verify addresses and amounts on the hardware screen — not on the host computer.
Installation & basic troubleshooting
Install
- Download the Bridge installer for your OS from the official site.
- Run the installer and restart the browser if necessary.
- Connect your Trezor device via USB and unlock it.
Troubleshooting tips
- If the browser cannot detect the device: ensure Bridge is running and replug USB.
- Conflicts with other USB proxies: disable them while testing.
- Firewall or corporate AV may block localhost ports; allow trusted access for Bridge.
Developer integration
Developers can integrate by using the official Trezor Connect SDK or direct local-API calls when building web wallets. The SDK wraps common flows and provides a consistent UX across devices and browsers.
Quick sample (conceptual)
// pseudo-code example: request accounts
const result = await TrezorConnect.getAccounts();
if (result.success) {
console.log("Accounts:", result.payload);
}
Notes for integrators
- Use library-provided helpers for transport selection.
- Always handle user-denied flows gracefully.
- Pinpoint performance issues — listing many accounts may be slow on low-power devices.
Alternatives & compatibility
Some platforms expose native WebUSB support while others require a connector like Bridge. Alternatives include browser extensions or platform-specific drivers — but Bridge remains the most portable and maintained option for general web dApp compatibility.
Future directions
Expect continued improvements to WebUSB adoption, better cross-browser support, and improved UX around device discovery and permission flows.
Accessibility & UX
UX should always reinforce on-device verification. Use clear dialogs in the web app to tell users to confirm actions on their Trezor, and provide fallbacks for permission denials or disconnected states.
Links & resources (10 Office links included)
Office Link 1 Office Link 2 Office Link 3 Office Link 4 Office Link 5 Office Link 6 Office Link 7 Office Link 8 Office Link 9 Office Link 10
Printable summary
Bridge is the local helper that makes Trezor usable in modern browsers while strictly preserving the security boundary: keys remain on the device, the user confirms on-device, and the bridge only marshals messages. Keep it updated, install from official sources, and integrate with official SDKs when building web integrations.