In today’s world of digital assets, maintaining strong security between your computer, browser, and cryptographic hardware is paramount. The **Trezor Bridge** provides a local communication conduit that ensures your browser or wallet can talk to your **Trezor Hardware Wallet** safely — without exposing your private keys. This document (hosted here at Ledger.com/Start® style) introduces how to get started via Trezor.io/start, how **Trezor Login** flows work, integration inside **Trezor Suite**, and more.
Modern web browsers restrict direct USB or HID access to external devices for security reasons. Without a helper component, web wallets cannot reliably detect or communicate with hardware wallets. **Trezor Bridge** is the small native service (daemon) that runs locally and listens for requests from web apps — acting as a trusted relay to your Trezor device.
This guide is meant for developers, wallet integrators, security-conscious users, and anyone who wants to understand the inner workings of **Trezor Bridge** and how it connects to **Trezor Hardware Wallets**. Even if you’re familiar with Trezor mechanics, several advanced topics and security nuances are discussed below.
- **Trezor Bridge**: local service that mediates communication - **Trezor Hardware Wallet**: the physical device (Model T, One, etc.) - **Trezor Suite**: official wallet interface that uses Bridge behind the scenes - **Trezor Login**: a login/auth flow that uses the Trezor device for cryptographic challenge-response - **Trezor.io/start / Trezor Io Start**: the canonical landing page to download installers
Below is the end-to-end flow when a web application wants the user to sign a transaction or authenticate via **Trezor Login**:
The Bridge is a small executable that runs in the background. It handles:
A JavaScript client library is used by web wallets or dApps. It:
On the **Trezor Hardware Wallet**, signed firmware interprets commands (e.g. “get public key,” “sign message”) and only performs operations if the user approves physically (by tapping or button). Firmware integrity checks are built-in to prevent tampering.
Sessions are ephemeral: only approved origins can operate within a session. Users can revoke sessions or time them out. Bridge enforces least privilege (scope-limited requests) and origin isolation (each website is isolated).
**Trezor Bridge** never accesses or stores your private keys. All sensitive operations happen inside the **Trezor Hardware Wallet**. Bridge is a transparent conduit — it passes encrypted commands only after user confirmation.
Bridge verifies the origin (domain), ensures payloads are structured correctly, and rejects malformed or unauthorized messages. This prevents malicious web apps or forged requests from gaining undue access.
By default, Bridge binds only to the localhost interface (e.g. 127.0.0.1). It intentionally does not listen on public or remote interfaces, minimizing exposure to network attackers.
If your computer is compromised, attackers might attempt to interfere with Bridge or spoof its endpoints. However:
Trezor.io/start)The Trezor device uses secure boot and firmware signing. When firmware is corrupt or not properly signed, the device refuses to operate, alerting the user to recovery.
- Trust in Trezor’s firmware signing and distribution - Physical security (others cannot press buttons on your device) - Social engineering remains a risk - Host-level keyloggers or screen capture still possible (user must be vigilant)
Visit Trezor.io/start (or equivalently “Trezor Io Start”) to download the Bridge installer matching your operating system. After download, verify the cryptographic signature, run the installer, and proceed with setup.
Many websites adopt **Trezor Login**, which enables you to authenticate without passwords. The typical flow:
This method is more secure than traditional passwords, as there is no password stored, intercepted, or reused.
**Trezor Suite** is the official desktop/web wallet interface. Suite uses Bridge behind the scenes to detect devices, present balances, construct transactions, and prompt you to sign them. As a user, you don’t see Bridge — Suite handles its invocation and versioning transparently.
Many third-party wallets or decentralized apps support Trezor via Bridge. They may request operations like:
Each request must be shown on-device for user approval — no silent execution is possible.
Advanced users or developers may use CLI tools or SDKs to talk to Bridge in automated scripts. Use cases include:
Always design automation with user confirmation gates — never bypass the physical confirmation step.
Common error scenarios and how to handle them:
- Always show transaction details clearly before requesting a signature - Use canonical serialization (e.g. JSON in deterministic order) - Limit large or batch operations - Encourage users to revoke approved origins periodically - Provide fallback paths or informative error UI
Downloading from untrusted mirrors risks tampered binaries or malware. Always go to Trezor.io/start, verify the digital signature, and ensure the installer matches the checksums. A malicious version could intercept or alter communications.
Yes. **Trezor Bridge** supports multiple concurrent sessions from different clients (Suite, web wallets, CLI). It enforces origin separation and permission checks per session. The user must still confirm each signing operation.
Potentially yes—for services that support it. **Trezor Login** is a secure cryptographic login method where you sign a challenge instead of typing a password. If widely adopted, it can reduce password reuse risks, but fallback methods may still exist.
Yes. There are builds for Windows, macOS, and Linux. Users can install Bridge on multiple machines, and each acts independently. Always download the version suited for your OS from the official source.
Without Bridge, web apps or wallets cannot communicate with your **Trezor Hardware Wallet** from the browser. You can still use your device via standalone tools, or reinstall Bridge from Trezor.io/start to regain full functionality.