Overview
Tŕezor™ Bŕridgeʬ (short: Bridge) is intentionally simple: it is a local helper that solves device access problems faced by modern web browsers and native apps.
Browsers are sandboxed for safety and do not always provide seamless access to raw USB or HID devices across operating systems. Bridge fills the gap by running on the user’s machine,
exposing a secure, permissioned endpoint that authorized applications can use to communicate with Trezor hardware wallets. Bridge streamlines the overall user experience without weakening the strong security model of Trezor devices.
What Bridge does
- Detects Trezor devices when they are plugged in and manages enumeration.
- Handles browser permission prompts and maps them to local authorizations.
- Relays APDU and JSON-RPC messages between apps and the device, without exposing private keys.
- Optionally checks for updates and helps maintain compatibility with the latest browser APIs.
What Bridge does not do
- It never requests or stores your recovery seed, private keys, or passphrases.
- Bridge does not broadcast transactions — signed payloads are returned to the calling app for broadcast via the app’s configured network provider.
- It does not perform signing or any cryptographic key operations — the Trezor device does that internally.
How Bridge fits the security model
The security of a hardware wallet depends on keeping private keys isolated. Bridge reinforces that model by acting purely as a communications layer.
All sensitive operations — key generation, signature creation, and PIN/passphrase entry — occur on the physical device. Bridge merely transmits and receives request/response packets.
For web applications, Bridge mediates permission grants and provides a predictable way to find and talk to the device without requiring specialized drivers.
Security & Privacy
Security principles are baked into the design. Bridge follows the least-privilege philosophy: it runs as a local service with minimal system permissions, listens only on loopback interfaces,
and requires explicit user authorization to allow browsers or apps to access a specific device session. Privacy is respected: telemetry is opt-in, and Bridge collects at most anonymized diagnostics
only when enabled by the user to help debug compatibility issues.
Permission flow
When an application requests access to a Trezor device, Bridge surface a native permission prompt or browser-integrated prompt that the user must approve.
The approval is ephemeral and scoped to the requesting origin or application. This behavior prevents background web pages or random applications from silently accessing your device.
Always check the origin and the exact device fingerprint before authorizing access.
Firmware validation & updates
While Bridge does not modify firmware, the Bridge installer and the official client apps verify firmware signatures and encourage users to install signed releases only.
Bridge can optionally help coordinate firmware updates by launching the official Suite or update flow, ensuring users apply authentic, signed firmware to their devices.
Developer integrations
Bridge is intentionally developer-friendly. Client libraries abstract the underlying transport so integrators can write code that discovers devices, opens secure channels, forwards commands,
and receives responses without dealing with low-level OS USB quirks. Typical integration steps include: detect -> request permission -> open channel -> exchange APDUs -> close channel.
The official libraries include examples for Node.js, browser-based WebUSB fallbacks, and common RPC patterns used by wallets and exchanges.
Sample flow for web apps
- App requests access through the Bridge client API.
- Bridge shows a native permission prompt and maps the approval to the browser origin.
- App sends a discovery command; Bridge returns a device ID and capabilities.
- App exchanges commands (e.g., getPublicKey, signTransaction); Bridge relays them; the device responds.
- App receives signed payloads and broadcasts via chosen network provider.
Testing & debugging
Developers can enable verbose diagnostics in Bridge to capture logs for device enumeration and transport-level errors. These logs are invaluable for diagnosing platform-specific USB or permission issues.
When reporting bugs, always include Bridge version, OS and arch, browser version (if applicable), and a minimal reproduction case.
Installation & first run
Installing Bridge is straightforward: download the platform-specific installer from the official site and run it. On first run, Bridge will start a local service and optionally open a helper page showing status.
For browser use, ensure the browser supports the required APIs and that you’re on a secure (HTTPS) origin. When connecting a Trezor device for the first time, Bridge will detect it and surface a one-time permission request.
After approval, your chosen app can communicate with the device until you revoke or restart the session.
Common troubleshooting
- Device not found: Try a different USB cable/port and confirm Bridge is running in the system tray/services panel.
- Permission prompt missing: Make sure the browser is up to date and you’re on a secure origin; try restarting the browser and Bridge service.
- Driver issues (legacy OS): Some older systems may need vendor drivers; consult the official docs for platform-specific instructions.
Privacy & telemetry
Respect for user privacy is a core goal. Bridge operates locally and transmits nothing about your keys or transactions to remote servers. Telemetry and crash reporting are optional — users can opt-in to provide anonymous usage metrics that help developers prioritize fixes.
Any collected data is aggregated, stripped of personally identifying information, and used solely for improving reliability and compatibility.
Enterprise & advanced deployments
Organizations can centrally distribute Bridge installers with customized update channels, disable auto-update behavior, and configure permissive policies for managed environments.
This flexibility is useful for kiosks, corporate labs, and onboarding flows where device access must be predictable and auditable across many workstations.