LedgerHQ
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@ledgerhq/hw-transport-webusb
Allows to communicate with Ledger Hardware Wallets.
[Web] (WebUSB) – WebUSB check browser support.
Are you adding Ledger support to your software wallet?
You may be using this package to open a USB connection between your web application and the device.
For a smooth and quick integration:
- See the developers’ documentation on the Developer Portal and
- Go on Discord to chat with developer support and the developer community.
FAQ: "DOM Exception" is triggered when creating the transport
The transport functions create() and listen() must be called in the context of a user interaction (like a "click" event), otherwise it fails with DOM Exception. This is by WebUSB design. You also must run on HTTPS.
How to use this transport regarding WebUSB paradigm?
In WebUSB, we have a "permission native" modal that appears when we need to "request" a device. This is required at-least-once for the user to accept, and then we can open the transport without triggering this modal. However, in both cases, it must happen in context of a click like explain above. Our current implementation trade off is to abstract this out and only trigger the permission modal if no device are listed. This might change in the future.
In terms of UX, there are two classical use cases:
- you only need the device at key times, like once to get the address. once to sign a transaction,...
- your app lifecycle requires that you need to access the device at the beginning and/or at any time (like you want to ping with getAddress to get the wallet address)
in (1) case, you can just do your logic in each button (Get Address / Sign Transaction) time (create it, do the logic, close it).
in (2) case, you will need to have a Connect button that appear when you don’t have the connection yet. And you need to hook to the “disconnect” event to potentially make the UI reflect that and require user to click again on that Connect button, because you can’t automatically create()/open() again.
Support status
WebUSB is currently only supported on Google Chrome / Chromium.
- In Linux, user need to install the specific udev rules
- In Mac, it should work.
- In Windows, WebUSB does not work out of the box but you can fix it with Zadig.
- In Android Chrome it works.
API
Table of Contents
TransportWebUSB
Extends Transport
WebUSB Transport implementation
Parameters
deviceUSBDeviceinterfaceNumbernumber
Examples
import TransportWebUSB from "@ledgerhq/hw-transport-webusb";
...
TransportWebUSB.create().then(transport => ...)
close
Release the transport device
Returns Promise\<void>
exchange
Exchange with the device using APDU protocol.
Parameters
apduBuffer
Returns Promise[Buffer](https://nodejs.org/api/buffer.html) a promise of apdu response
isSupported
Check if WebUSB transport is supported.
list
List the WebUSB devices that was previously authorized by the user.
listen
Actively listen to WebUSB devices and emit ONE device that was either accepted before, if not it will trigger the native permission UI.
Important: it must be called in the context of a UI click!
Parameters
observerObserver\<DescriptorEvent\<USBDevice>>
Returns Subscription
request
Similar to create() except it will always display the device permission (even if some devices are already accepted).
openConnected
Similar to create() except it will never display the device permission (it returns a Promise\<?Transport>, null if it fails to find a device).
open
Create a Ledger transport with a USBDevice
Parameters
deviceUSBDevice