Trezor Bridge – Official Connection Tool

What is Trezor Bridge?

Trezor Bridge is a small, cross-platform background application that runs on your computer and exposes a local API to web pages and native apps. Instead of using raw USB or platform-specific APIs, apps communicate with Bridge using HTTP/WebSocket-like calls that Bridge translates into the appropriate low-level messages (APDUs) sent to the Trezor device. This model improves compatibility across browsers and operating systems while keeping the hardware interaction secure and predictable.

Why use Bridge?

• Cross-platform support: Bridge abstracts OS differences so the same application code works on Windows, macOS, and Linux.
• Browser compatibility: Modern browsers restrict raw USB access; Bridge provides a reliable complement for web-based wallet flows without requiring browser extensions.
• Secure transport: Bridge limits the surface exposed to web pages and applications and enforces local origin checks for browser integrations where applicable.
• Simplified developer experience: Developers use higher-level APIs provided by Bridge-compatible libraries instead of handling low-level USB or HID protocols.

Supported platforms & installation

Trezor Bridge is available for Windows, macOS and Linux. Installation packages are provided on the official Trezor website and include signed installers for each platform. For most users, the recommended flow is:

1. Download Bridge from the official Trezor site. Verify the download if a checksum/signature is provided.
2. Run the installer and follow platform-specific prompts (Windows installer, macOS package, Linux package or AppImage where available).
3. After installation, Bridge runs as a background service and automatically starts when a supported application requests device access.

On some Linux distributions you may need to configure udev rules or set executable permissions on the Bridge binary. Consult the platform notes in the official documentation for details.

Security model

Bridge operates on the principle of minimal trusted computing: the private keys remain inside the Trezor device at all times and Bridge only mediates transport. Key security aspects include:

• Local-only API: Bridge listens on localhost and does not accept remote connections by default. This reduces exposure to network-based attackers.
• Origin checking: For browser integrations, Bridge validates the origin of web pages requesting access and prompts the user to confirm unusual requests where appropriate.
• Transport isolation: Bridge isolates USB/HID/BLE transport handling from app-level logic, reducing the chance that buggy host code can corrupt device communications.
• Signed firmware verification: The Trezor device itself verifies firmware signatures and is the final arbiter of code that runs on the device.

Using Bridge with Trezor Suite and web apps

Trezor Suite and many web wallets detect Bridge automatically. The typical flow for a web integration looks like this:

1. User navigates to a compatible web wallet.
2. Wallet library checks for Bridge on localhost and, if needed, prompts the user to install or start Bridge.
3. After Bridge is available, the wallet requests device discovery and listing through Bridge’s local API.
4. When the user picks a device and initiates an operation, the wallet builds the transaction, sends a signing request to Bridge, which forwards the APDU commands to the Trezor device for user confirmation and signing.
5. Signed transactions are returned through Bridge to the wallet and broadcast to the network by the wallet or a configured relayer.

The user always confirms operations on the Trezor device display, which is the authoritative interface for preventing host-side tampering.

Developer integration tips

Developers building Bridge-compatible apps should follow these best practices:

• Use official libraries: Leverage Trezor’s maintained client libraries and SDKs — they encapsulate transport logic and APDU construction and are tested against device behavior.
• Minimize host-side secrets: Avoid storing sensitive material on the host; perform as much validation as possible in human-readable form and rely on device verification for signing.
• Display clear UX prompts: Show users explicit, human-readable transaction summaries before requesting device signatures. Make it easy to abort operations.
• Handle errors gracefully: Devices can disconnect, or users can reject operations. Implement robust retry and cancel logic rather than assuming success.
• Test across platforms: Validate behavior on Windows, macOS, and several Linux distros to catch platform-specific quirks.

Privacy & telemetry

Bridge itself transmits minimal telemetry. Official distributions aim to respect user privacy — Bridge does not send private keys, passphrases, or transaction content to remote servers. When using Bridge with third-party wallets, review those wallets’ privacy policies: some services may query external indexers or analytics providers which could expose metadata about your addresses or balances. If privacy is a priority, use local nodes or trusted relayers where supported.

Troubleshooting common Bridge issues

• Web wallet prompts to install Bridge: Follow official Bridge download links—do not trust third-party mirrors.
• Bridge connection errors: Check for firewall or security software that might block localhost connections.

Security considerations & best practices

• Download Bridge only from the official Trezor website and verify signatures when provided.
• Keep your operating system and Bridge updated to receive security fixes.
• Use the device’s screen to verify transaction details — the hardware confirmation is your strongest protection against host-side manipulation.
• Prefer official Trezor Suite or well-reviewed third-party wallets that follow UX and security best practices for hardware wallets.

Future directions & integration roadmap

Trezor Bridge continues to evolve for better browser compatibility, performance improvements, and streamlined developer workflows. Future updates may further reduce friction for web-based dApps while preserving the security model that keeps keys inside the device. Developers should subscribe to the official Trezor developer channels and release notes for migration guides and API changes.

FAQ

Q: Is Bridge required to use a Trezor device?
A: Bridge is required for many desktop and web integrations on older browsers and environments; however, certain apps and native integrations may use direct USB or alternate transports where supported.

Q: Can Bridge be accessed remotely?
A: Bridge listens on localhost by default and should not be exposed to remote networks. Avoid configuring it to listen on external interfaces.

Conclusion

Trezor Bridge is the official, secure connectivity layer that enables a wide ecosystem of wallets and dApps to interoperate with Trezor hardware wallets. By abstracting platform-specific transport details and enforcing local origin and transport checks, Bridge simplifies development while preserving the core security guarantees of on-device key custody. Follow installation, update, and verification guidance from official sources, verify transactions on-device, and use trusted applications to ensure a secure and reliable experience.