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@ledgerhq/hw-transport implements the generic interface of a Ledger Hardware Wallet transport.
- Subscription
- Device
- DescriptorEvent
- Observer
- Transport
Type: {unsubscribe: function (): void}
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unsubscribefunction (): void
Type: any
A "descriptor" is a parameter that is specific to the implementation, and can be an ID, file path, or URL. type: add or remove event descriptor: a parameter that can be passed to open(descriptor) deviceModel: device info on the model (is it a nano s, nano x, ...) device: transport specific device info
Observer generic type, following the Observer pattern
Type: Readonly<{next: function (event: EventType): any, error: function (e: EventError): any, complete: function (): any}>
The Transport class defines a generic interface for communicating with a Ledger hardware wallet. There are different kind of transports based on the technology (channels like U2F, HID, Bluetooth, Webusb) and environment (Node, Web,...). It is an abstract class that needs to be implemented.
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$0{context: TraceContext?, logType: LogType?} (optional, default{})-
$0.context -
$0.logType
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Send data to the device using a low level API. It's recommended to use the "send" method for a higher level API.
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_apduBuffer -
optionsObject Contains optional options for the exchange function* abortTimeoutMs: stop the exchange after a given timeout. Another timeout exists to detect unresponsive device (seeunresponsiveTimeout). This timeout aborts the exchange. (optional, default{})-
options.abortTimeoutMs
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apduBuffer The data to send.
Returns Promise<Buffer> A promise that resolves with the response data from the device.
Send apdus in batch to the device using a low level API. The default implementation is to call exchange for each apdu.
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apdusArray<Buffer> array of apdus to send. -
observerObserver<Buffer> an observer that will receive the response of each apdu.
Returns Subscription A Subscription object on which you can call ".unsubscribe()" to stop sending apdus.
Set the "scramble key" for the next data exchanges with the device. Each app can have a different scramble key and it is set internally during instantiation.
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_keystring -
keystring The scramble key to set. deprecated This method is no longer needed for modern transports and should be migrated away from. no @ before deprecated as it breaks documentationjs on version 14.0.2 https://github.com/documentationjs/documentation/issues/1596
Close the connection with the device.
Note: for certain transports (hw-transport-node-hid-singleton for ex), once the promise resolved, the transport instance is actually still cached, and the device is disconnected only after a defined timeout. But for the consumer of the Transport, this does not matter and it can consider the transport to be closed.
Returns Promise<void> A promise that resolves when the transport is closed.
Listen for an event on the transport instance. Transport implementations may have specific events. Common events include: "disconnect" : triggered when the transport is disconnected.
Returns void
Stop listening to an event on an instance of transport.
Returns void
Enable or not logs of the binary exchange
Set a timeout (in milliseconds) for the exchange call. Only some transport might implement it. (e.g. U2F)
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exchangeTimeoutnumber
Returns void
Define the delay before emitting "unresponsive" on an exchange that does not respond
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unresponsiveTimeoutnumber
Returns void
Send data to the device using the higher level API.
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clanumber The instruction class for the command. -
insnumber The instruction code for the command. -
p1number The first parameter for the instruction. -
p2number The second parameter for the instruction. -
dataBuffer The data to be sent. Defaults to an empty buffer. (optional, defaultBuffer.alloc(0)) -
statusListArray<number> A list of acceptable status codes for the response. Defaults to [StatusCodes.OK]. (optional, default[StatusCodes.OK]) -
optionsObject Contains optional options for the exchange function* abortTimeoutMs: stop the send after a given timeout. Another timeout exists to detect unresponsive device (seeunresponsiveTimeout). This timeout aborts the exchange. (optional, default{})-
options.abortTimeoutMs
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Returns Promise<Buffer> A promise that resolves with the response data from the device.
Wrapper to make an exchange "atomic" (blocking any other exchange)
It also handles "unresponsiveness" by emitting "unresponsive" and "responsive" events.
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ffunction (): Promise<Output> The exchange job, using the transport to run
Returns Promise<Output> a Promise resolving with the output of the given job
Sets the context used by the logging/tracing mechanism
Useful when re-using (cached) the same Transport instance, but with a new tracing context.
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contextTraceContext? A TraceContext, that can undefined to reset the context
Updates the context used by the logging/tracing mechanism
The update only overrides the key-value that are already defined in the current context.
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contextToAddTraceContext A TraceContext that will be added to the current context
Gets the tracing context of the transport instance
Returns (TraceContext | undefined)
Check if the transport is supported on the current platform/browser.
Type: function (): Promise<boolean>
Returns Promise<boolean> A promise that resolves with a boolean indicating support.
List all available descriptors for the transport.
For a better granularity, checkout listen().
Type: function (): Promise<Array<any>>
TransportFoo.list().then(descriptors => ...)Returns Promise<Array<any>> A promise that resolves with an array of descriptors.
Listen for device events for the transport. The method takes an observer of DescriptorEvent and returns a Subscription. A DescriptorEvent is an object containing a "descriptor" and a "type" field. The "type" field can be "add" or "remove", and the "descriptor" field can be passed to the "open" method. The "listen" method will first emit all currently connected devices and then will emit events as they occur, such as when a USB device is plugged in or a Bluetooth device becomes discoverable.
Type: function (observer: Observer<DescriptorEvent<any>>): Subscription
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observerObserver<DescriptorEvent<any>> An object with "next", "error", and "complete" functions, following the observer pattern.
const sub = TransportFoo.listen({
next: e => {
if (e.type==="add") {
sub.unsubscribe();
const transport = await TransportFoo.open(e.descriptor);
...
}
},
error: error => {},
complete: () => {}
})Returns Subscription A Subscription object on which you can call ".unsubscribe()" to stop listening to descriptors.
Attempt to create a Transport instance with a specific descriptor.
Type: function (descriptor: any, timeoutMs: number, context: TraceContext): Promise<Transport>
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descriptorany The descriptor to open the transport with. -
timeoutnumber An optional timeout for the transport connection. -
contextTraceContext Optional tracing/log context
TransportFoo.open(descriptor).then(transport => ...)Returns Promise<Transport> A promise that resolves with a Transport instance.
create() allows to open the first descriptor available or throw if there is none or if timeout is reached. This is a light helper, alternative to using listen() and open() (that you may need for any more advanced usecase)
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openTimeout(optional, default3000) -
listenTimeoutnumber?
TransportFoo.create().then(transport => ...)