Trezor Bridge – Official Connection Tool (H1)

A comprehensive soft-light themed, accessible single-file reference for installing, integrating, and understanding Trezor Bridge. Multiple presentation formats are included to suit different audiences: quick reference, developer docs, troubleshooting, and printable summary.

Version: 2.x.example

Channel: Stable

Official tool

Connect hardware wallets to web apps with a secure local bridge

Trezor Bridge is a lightweight, local application that establishes secure communication between your Trezor hardware wallet and web applications. This page is a template and deep reference demonstrating recommended flows, security patterns, developer examples, and user-facing instructions — all in a soft, approachable visual theme.

Security-first

Bridge minimizes attack surface by keeping communication local. Private keys remain on-device; Bridge only routes approved messages.

Cross-platform

Installers and packages are provided for Windows, macOS, and major Linux distributions. A lightweight auto-update option is available for convenience and security.

Developer-friendly

Local HTTP endpoints and a small SDK allow web apps to detect devices, initiate actions, and receive callbacks for user confirmations.

Open & auditable

Bridge components and utilities are designed to be auditable. Follow secure build practices and reproducible artifacts for maximum trust.

Quick start

Download the Bridge installer matching your operating system.
Run the installer; allow any system prompts for network permissions.
Connect your Trezor device by USB or supported transport.
Open a compatible web app. Authorize the connection on the device when requested.

Example: detect devices (browser)

fetch('http://127.0.0.1:21325/api/device/list')
  .then(r => r.json())
  .then(devices => {
    console.log('Attached devices:', devices);
  })
  .catch(err => {
    console.error('Bridge not reachable', err);
  });

This sample queries the local Bridge API port. Replace port and path with the values your Bridge exposes in production.

Local bridge illustration • sample only

Alternate presentation formats

Choose how information is presented depending on your audience: concise cards for marketing, table for specs, accordion for detailed docs, or timeline for release history.

What is Bridge?

Trezor Bridge is a local background application that enables secure transport between hardware wallets and browser-based applications without exposing private keys.

Why use it?

Bridge provides cross-browser compatibility, a stable local transport layer, and a consistent developer API without relying on browser extensions.

How it works

Bridge listens on a loopback port; web applications connect locally and request device actions which require user confirmation on the device itself.

For developers

Use the local HTTP endpoints or SDK wrappers to detect devices, send commands, and listen for approval callbacks from the user's Trezor.

Feature	Description	Notes
Local-only	Bridge operates on 127.0.0.1 only by default.	Reduces remote attack surface.
Auto-update	Optional auto-update ensures timely security patches.	Can be disabled for managed installs.
Open-source	Source code available for auditing and reproducible builds.	Encourages community review.
Cross-platform	Windows, macOS, Linux binaries and packages.	Packaged with OS conventions.
Minimal privileges	Does not store private keys or persist sensitive payloads.	Logs are minimal and sanitized.

Detailed comparison: Bridge vs Browser Extension

Aspect	Bridge	Browser extension
Installation	Desktop installer — one-time	Install from browser store — per browser
Security surface	Local host only, minimal persisted data	Runs inside browser process — larger attack surface
Browser support	All modern browsers (via loopback)	Depends on extension APIs and browser vendor
Update path	Centralized auto-update option	Managed through browser extension stores
Use case	Best for hardware wallets and general web app compatibility	Good for lightweight in-browser wallets without hardware

Developer & integration notes

This section provides examples, UX patterns, API endpoints, and security guidance. Use these as a baseline and adapt to your application's needs.

JavaScript: basic device list

async function getDevices() {
  try {
    const res = await fetch('http://127.0.0.1:21325/api/device/list', {cache: "no-store"});
    if (!res.ok) throw new Error('Bridge not reachable');
    return await res.json();
  } catch (err) {
    console.error('Bridge error', err);
    throw err;
  }
}

UX pattern

When requesting a hardware action, present a modal that explains the action, expected device prompts, and fallback steps. Use clear concrete verbs like “Confirm on your Trezor” rather than vague technical language.

Security checklist

Validate the origin of requests on the client before forwarding to Bridge.
Rate-limit repeated requests and expose exponential backoff.
Log minimally, redact identifiable fields, and rotate logs in managed environments.
Use explicit confirmations for signing and high-impact actions.

API reference (selected endpoints)

GET /api/device/list — lists attached hardware devices.
POST /api/device/{id}/sign — request a signature action; requires user confirmation on device.
GET /api/version — returns Bridge version and build metadata.

Example: request signature (pseudo)

fetch('http://127.0.0.1:21325/api/device/abc123/sign', {
  method: 'POST',
  headers: {'Content-Type': 'application/json'},
  body: JSON.stringify({message: '0xdeadbeef'})
})
  .then(r => r.json())
  .then(res => console.log('signature', res))
  .catch(err => console.error('sign error', err));

Troubleshooting & FAQ

Cannot detect device

Ensure Bridge is running and has permission on your OS. Try toggling USB connection, use a different cable, and check browser console for CORS or network errors. On Windows, inspect Device Manager for missing drivers.

Browser errors while connecting

Modern browsers sometimes block loopback connections due to security settings. Ensure you have not blocked 127.0.0.1 and that any corporate proxy/firewall rules permit local connections.

Updating Bridge

If automatic updates are enabled, Bridge will prompt to restart or install updates. For managed environments, distribute approved packages via your standard software management tools.

Privacy concerns

Bridge avoids storing private keys and minimizes telemetry. Review the project's privacy policy and source code if you need to confirm specific behaviors for compliance purposes.

FAQ (short)

Q: Does Bridge transmit keys to external servers?
A: No — private keys never leave the Trezor device. Bridge only forwards signed messages as approved by the user.

Q: Can I run Bridge in a headless environment?
A: Some enterprise builds support headless deployments with privileged service wrappers; consult your organization's deployment guidelines.

Q: Is Bridge open-source?
A: Core components are published for audit; follow the official repository and release notes to review code and reproducible builds.

Printable summary

This section is tailored for printing: it includes concise installation steps, troubleshooting highlights, and the security checklist. Interactive controls and non-essential visuals are hidden in print media for clarity.

One-page checklist

Download installer for your OS.
Install and allow loopback/network permissions.
Connect Trezor device and verify device firmware.
Open compatible web app and allow device connection.
Keep Bridge updated and review release notes for security advisories.