About Trezor Bridge

Trezor Bridge is the official local bridge that enables communication between Trezor devices and host applications (browsers, desktop apps). It runs as a local daemon and exposes an HTTP API on the loopback interface for privacy and safety.

What’s new in this expanded guide

• Deeper diagnostics and log analysis for support teams.
• Advanced operational and developer recommendations.
• Recovery strategies and checklist for common failure modes.
• Clear, legally framed disclaimer and sourcing guidance.

Advanced Diagnostics

When basic troubleshooting fails, collect richer data to identify root causes. The steps below assume administrative access to the host system.

Collecting verbose logs (Linux)

sudo journalctl -u trezor-bridge.service --since "1 hour ago" > trezor_bridge_recent.log
sudo journalctl -u trezor-bridge.service -n 200 --no-pager

Windows diagnostics

Enable verbose logging if supported by the Bridge binary, and collect Event Viewer entries under Application and Service logs. Also inspect files under %APPDATA%\trezor-bridge for rotating logs.

macOS diagnostics

log show --predicate 'process == "trezor-bridge"' --last 1h
ps aux | grep trezor

Advanced Recovery Checklist

1. Confirm device hardware: test the Trezor on another machine to rule out device-level issues.
2. Verify USB cable and port; prefer original cables and avoid USB-C adapters when possible.
3. Collect logs and search for keywords: permission, usb, bind, address, exception.
4. Temporarily disable strict privacy browser extensions and retry a connection.
5. If service repeatedly fails on start, reinstall the Bridge and reboot the host to clear orphaned resources.

Developer Deep-Dive

Integrators should treat the Bridge API as a trusted local resource but assume the host may be compromised. Always present transaction details on-device and require users to confirm operations on the hardware display.

Sample flow: enumerate devices and ping bridge

async function pingBridge(){
  const r = await fetch('http://127.0.0.1:21324/info', {cache:'no-store', mode:'cors'});
  return r.ok ? await r.json() : null;
}

Use retries with exponential backoff when waiting for Bridge to start during an app launch sequence.

Operational Hardening

For organizations that support users at scale, add the following controls:

• Documentation: maintain an internal KB mapping OS versions to known Bridge issues.
• Verification: provide checksum or PGP-signed hashes for installers and teach support staff how to verify them.
• Isolation: discourage users from installing untrusted browser extensions that can interact with localhost APIs.

Legal & Safety Disclaimer

This document is educational, not an official Trezor or SatoshiLabs publication. Always download Bridge and firmware from the official site (trezor.io). Do not install unofficial or pirated binaries. The authors are not liable for any loss arising from use of this guide. Cryptocurrency operations carry financial risk — exercise due diligence and consult qualified professionals for legal, tax or investment advice.