Trezor Bridge – The Secure Gateway to Your Hardware Wallet®

Presentation, installation & migration guidance, developer notes
Open Trezor Suite

Executive summary

Trezor Bridge has historically acted as the local transport layer between Trezor hardware wallets and host software — enabling secure, authenticated communication between your browser or desktop applications and the device over USB/HID. While modern alternatives and in-app integrations (notably Trezor Suite) are now recommended for most users, Bridge remains an important chapter in how Trezor devices were connected to host apps and a useful tool for developers and specific legacy setups. :contentReference[oaicite:0]{index=0}

How Bridge works (high level)

At its core, Bridge runs as a small local daemon on your machine. The daemon listens on a localhost HTTP endpoint and translates requests from web pages or apps into USB/HID commands the Trezor hardware understands. Because it runs locally, Bridge does not send device secrets over the internet — it simply forwards protocol messages and ensures communication is properly routed and sessionized.

Why it was introduced

Bridge solved a practical problem: browsers historically restricted direct access to raw USB/HID devices, and browser plugins or non-standard APIs created security and compatibility headaches. By offering a small, cross-platform helper, Trezor enabled web-based wallets to interact with hardware wallets reliably while keeping user confirmations on the physical device.

Security posture & privacy

Two core security guarantees remain central:

  • Keys never leave the device: All private keys and sensitive signing operations remain on the hardware wallet; Bridge only transports messages between host and device.
  • Local-only connectivity: Bridge listens on localhost and accepts connections from local applications. Remote parties cannot directly interact with your device through Bridge without local access or compromise.

Important changes & migration guidance

Trezor has publicly documented the deprecation and removal process for the standalone Trezor Bridge. For a smoother user experience, and to reduce compatibility problems in future releases, Trezor recommends that most users rely on Trezor Suite (desktop or web) rather than a separate Bridge installation. If you do have Bridge installed, follow the official removal and migration instructions before switching to Suite to avoid conflicts. :contentReference[oaicite:1]{index=1}

When you should migrate

Migrate if you:

  • Use Trezor Suite as your primary wallet app (Suite integrates transport handling and keeps updates centralized).
  • See messages recommending removal of standalone Bridge in your Suite or support notices.
  • Want fewer moving parts and easier maintenance across OS updates.

Developer notes — integrating hardware wallets

Developers who build integrations with Trezor should treat Bridge as a platform transport mechanism. Open-source repositories such as trezord-go provide the reference daemon implementation and are an excellent starting point for understanding the expected behavior (session handling, USB/HID translation, reconnect logic). For modern integrations, check whether WebUSB or Suite modes cover your needs before shipping a Bridge-dependent approach. :contentReference[oaicite:2]{index=2}

Best practices for devs

  • Design a clear session lifecycle; avoid global singleton races across tabs.
  • Present minimal, unambiguous information in the host UI — always require on-device confirmation and show only context needed to make a safe decision.
  • Gracefully handle device attach/detach and stale-daemon states (prompt users with clear steps to restart Bridge or Suite).

Troubleshooting & common issues

Frequently encountered problems include stale or conflicting Bridge installations, permission restrictions on certain OSes, and browser-level API conflicts. Typical recovery steps:

  • Restart the Bridge/trezord process and the browser.
  • Check that you are not running both a legacy standalone Bridge and a Suite-instantiated transport at the same time.
  • If necessary, uninstall standalone Bridge per the official removal instructions and reinstall Suite or the latest transport components. :contentReference[oaicite:3]{index=3}

Practical checklist (for users)

1) Decide whether you want to use Trezor Suite (recommended) or a standalone Bridge (legacy). 2) If moving to Suite, back up any important data, uninstall standalone Bridge following the official guide, and install Suite. 3) Check your device firmware and apply official firmware updates through Suite. 4) For developer or advanced workflows, consult trezord-go and the Trezor developer guides.

Sample dev snippet

fetch('http://127.0.0.1:21325/') .then(r => r.text()) .then(console.log) .catch(err => console.warn('Bridge not reachable', err));

FAQ — quick answers

Q: Will uninstalling Bridge break my device?

A: No — the device stores keys independently. Uninstalling Bridge removes the local transport; use Trezor Suite (or another supported transport) to continue using the device. :contentReference[oaicite:4]{index=4}

Q: Do new Trezor devices require Bridge?

A: Newer devices and Stack approaches (WebUSB + Suite) reduce the need for a standalone Bridge, but Bridge/trezord remain relevant for specific environments and legacy setups. Consult current developer docs for exact compatibility. :contentReference[oaicite:5]{index=5}

Closing — recommended actions

For most users: adopt Trezor Suite for a unified experience and follow the official deprecation guidance before removing any Bridge components. For developers and advanced users: study trezord-go, design transports that respect session boundaries and device confirmations, and always keep firmware and client software up to date.