Trezor Bridge historically served as the local communication daemon that allowed browsers and desktop apps to communicate securely with a Trezor hardware wallet. This presentation explains what Bridge did, how it handled secure communication, why it changed, and practical guidance for developers and users when integrating or migrating to newer Trezor software (Trezor Suite and web integrations).
Trezor Bridge acted as a local USB-to-HTTP bridge. Running on the user’s computer, it exposed an API that browser-based wallet UIs and local apps could call to perform actions on a connected Trezor device. It bridged the gap between web technologies (JSON-RPC, websockets) and low-level USB/HID access required to talk to the hardware wallet.
Bridge was intentionally simple: it did not hold user keys, did not relay transactions over the network, and only provided a local channel between software and device. The hardware wallet itself remained the root of trust — signing and sensitive operations always occurred on-device. The combination of on-device cryptography plus explicit user confirmations minimized risk even if local software was compromised.
Developers commonly used official libraries (for example, trezor-connect and client integrations) which handled pairing, session creation, and JSON-RPC request/response parsing. On the backend, the Bridge process (trezord / trezord-go) translated HTTP calls into USB/HID requests handled by the Trezor device firmware.
// pseudo-code: call device through bridge
POST http://127.0.0.1:21324/json/ sessionId, protobufMessage
// trezord routes to device and sends protobuf response back
Over time Trezor moved functionality into Trezor Suite and updated web integration patterns. Standalone Trezor Bridge was deprecated in favor of more integrated, up-to-date mechanisms provided by the official apps and libraries. Users and integrators were advised to migrate to the Trezor Suite workflow for the latest compatibility and security improvements.
(Note: standalone Bridge has been officially deprecated — see guidance in the official Trezor guides.)
If a device is not discovered: check USB cable, confirm Bridge/Suite is running, avoid USB hubs, and verify OS drivers.
Uninstall old/standalone Bridge versions if using Trezor Suite. Follow official uninstall instructions per operating system.
The list below points to official Trezor and SatoshiLabs resources (click to open).
Tip: change the CSS variable --official-link-color at the top to update the link color across the presentation.
Trezor Bridge played an important role enabling secure local communication between apps and hardware wallets. The core security model — keeping keys on-device and requiring explicit confirmations — remains central to Trezor’s design regardless of integration approach. As the ecosystem evolves, follow official guidance, prefer the latest Trezor Suite and official libraries, and apply the security best practices described above to keep user funds safe.