Trezor Bridge — The Secure Gateway to Your Hardware Wallet®

Overview

What is Trezor Bridge?

Trezor Bridge is a background communication service that enables safe, reliable communication between a Trezor hardware wallet and applications such as Trezor Suite or compatible browser integrations. It mediates USB/HID access and provides a local API so web or desktop clients can interact with your device without exposing keys or seeds to the host environment.

Why Bridge exists

Operating systems and browsers restrict direct USB/HID access for web apps; Bridge provides a small, auditable layer that translates between device-level protocol and higher-level application calls, keeping low-level operations inside a narrow, well-defined boundary.

Security model

Design goals (h3)

Trezor Bridge’s security goal is simple: never reveal or transport private keys or seed material outside the device. All signing operations occur on the device: the host sends structured requests and receives back signatures or confirmation statuses only after explicit user approval on the Trezor screen.

Device-isolated secrets (h4)

The Trezor hardware keeps critical secrets (seed, private keys) inside secure storage and uses the Bridge only for message transport. Because the user confirms sensitive actions on the device display, malware on the host cannot silently extract funds.

Minimal host privileges (h4)

Bridge runs as a small service with a limited surface area — minimizing the code that must be trusted on the host machine. For advanced users and auditors, Bridge's code and related tooling are publicly available in official repositories.

User experience

Connecting your device (h3)

Modern setups often require the Trezor Suite application, where device detection is automatic. In legacy or browser-based workflows, Bridge acts behind the scenes to enable the connection. Note that Trezor has been consolidating Bridge functionality into Trezor Suite — users should follow official guidance when upgrading or uninstalling standalone Bridge components.

Confirmation and transparency (h5)

Every transaction or message requiring private key use shows a full preview on the Trezor device for mandatory user confirmation. This human-verifiable step is the key trust boundary.

Developer & advanced topics

APIs and integration

Developers can use official libraries (Connect, Bridge clients) to implement safe integrations. These libraries provide high-level functions for session creation, protobuf message exchange and session lifecycle management — reducing direct interaction with low-level USB/HID details.

Open source and audits

Bridge-related components and Trezor Suite are open-source, enabling independent review and community contributions. If you are building an integration, prefer official repos and packages rather than third-party forks.

Maintenance and lifecycle

Deprecation & migration (h3)

Trezor’s product guidance evolves: at times, standalone Bridge versions are deprecated in favor of explicit integration inside Trezor Suite. Follow official migration instructions to avoid compatibility issues and to keep your system secure.

When to uninstall standalone Bridge (h4)

If official guidance indicates deprecation, uninstall the standalone Bridge before switching to the integrated Suite version to avoid conflicts. Always use official installers and remove older packages through your OS’s uninstall mechanism.