electron/docs/tutorial/devices.md

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# Device Access
Like Chromium based browsers, Electron provides access to device hardware
through web APIs. For the most part these APIs work like they do in a browser,
but there are some differences that need to be taken into account. The primary
difference between Electron and browsers is what happens when device access is
requested. In a browser, users are presented with a popup where they can grant
access to an individual device. In Electron APIs are provided which can be
used by a developer to either automatically pick a device or prompt users to
pick a device via a developer created interface.
## Web Bluetooth API
The [Web Bluetooth API](https://web.dev/bluetooth/) can be used to communicate
with bluetooth devices. In order to use this API in Electron, developers will
need to handle the [`select-bluetooth-device` event on the webContents](../api/web-contents.md#event-select-bluetooth-device)
associated with the device request.
Additionally, [`ses.setBluetoothPairingHandler(handler)`](../api/session.md#sessetbluetoothpairinghandlerhandler-windows-linux)
can be used to handle pairing to bluetooth devices on Windows or Linux when
additional validation such as a pin is needed.
### Example
This example demonstrates an Electron application that automatically selects
the first available bluetooth device when the `Test Bluetooth` button is
clicked.
```javascript fiddle='docs/fiddles/features/web-bluetooth'
```
## WebHID API
The [WebHID API](https://web.dev/hid/) can be used to access HID devices such
as keyboards and gamepads. Electron provides several APIs for working with
the WebHID API:
* The [`select-hid-device` event on the Session](../api/session.md#event-select-hid-device)
can be used to select a HID device when a call to
`navigator.hid.requestDevice` is made. Additionally the [`hid-device-added`](../api/session.md#event-hid-device-added)
and [`hid-device-removed`](../api/session.md#event-hid-device-removed) events
on the Session can be used to handle devices being plugged in or unplugged
when handling the `select-hid-device` event.
**Note:** These events only fire until the callback from `select-hid-device`
is called. They are not intended to be used as a generic hid device listener.
* [`ses.setDevicePermissionHandler(handler)`](../api/session.md#sessetdevicepermissionhandlerhandler)
can be used to provide default permissioning to devices without first calling
for permission to devices via `navigator.hid.requestDevice`. Additionally,
the default behavior of Electron is to store granted device permission through
the lifetime of the corresponding WebContents. If longer term storage is
needed, a developer can store granted device permissions (eg when handling
the `select-hid-device` event) and then read from that storage with
`setDevicePermissionHandler`.
* [`ses.setPermissionCheckHandler(handler)`](../api/session.md#sessetpermissioncheckhandlerhandler)
can be used to disable HID access for specific origins.
### Blocklist
By default Electron employs the same [blocklist](https://github.com/WICG/webhid/blob/main/blocklist.txt)
used by Chromium. If you wish to override this behavior, you can do so by
setting the `disable-hid-blocklist` flag:
```javascript
app.commandLine.appendSwitch('disable-hid-blocklist')
```
### Example
This example demonstrates an Electron application that automatically selects
HID devices through [`ses.setDevicePermissionHandler(handler)`](../api/session.md#sessetdevicepermissionhandlerhandler)
and through [`select-hid-device` event on the Session](../api/session.md#event-select-hid-device)
when the `Test WebHID` button is clicked.
```javascript fiddle='docs/fiddles/features/web-hid'
```
## Web Serial API
The [Web Serial API](https://web.dev/serial/) can be used to access serial
devices that are connected via serial port, USB, or Bluetooth. In order to use
this API in Electron, developers will need to handle the
[`select-serial-port` event on the Session](../api/session.md#event-select-serial-port)
associated with the serial port request.
There are several additional APIs for working with the Web Serial API:
* The [`serial-port-added`](../api/session.md#event-serial-port-added)
and [`serial-port-removed`](../api/session.md#event-serial-port-removed) events
on the Session can be used to handle devices being plugged in or unplugged
when handling the `select-serial-port` event.
**Note:** These events only fire until the callback from `select-serial-port`
is called. They are not intended to be used as a generic serial port
listener.
* [`ses.setDevicePermissionHandler(handler)`](../api/session.md#sessetdevicepermissionhandlerhandler)
can be used to provide default permissioning to devices without first calling
for permission to devices via `navigator.serial.requestPort`. Additionally,
the default behavior of Electron is to store granted device permission through
the lifetime of the corresponding WebContents. If longer term storage is
needed, a developer can store granted device permissions (eg when handling
the `select-serial-port` event) and then read from that storage with
`setDevicePermissionHandler`.
* [`ses.setPermissionCheckHandler(handler)`](../api/session.md#sessetpermissioncheckhandlerhandler)
can be used to disable serial access for specific origins.
### Example
This example demonstrates an Electron application that automatically selects
serial devices through [`ses.setDevicePermissionHandler(handler)`](../api/session.md#sessetdevicepermissionhandlerhandler)
as well as demonstrating selecting the first available Arduino Uno serial device (if connected) through
[`select-serial-port` event on the Session](../api/session.md#event-select-serial-port)
when the `Test Web Serial` button is clicked.
```javascript fiddle='docs/fiddles/features/web-serial'
```
## WebUSB API
The [WebUSB API](https://web.dev/usb/) can be used to access USB devices.
Electron provides several APIs for working with the WebUSB API:
* The [`select-usb-device` event on the Session](../api/session.md#event-select-usb-device)
can be used to select a USB device when a call to
`navigator.usb.requestDevice` is made. Additionally the [`usb-device-added`](../api/session.md#event-usb-device-added)
and [`usb-device-removed`](../api/session.md#event-usb-device-removed) events
on the Session can be used to handle devices being plugged in or unplugged
when handling the `select-usb-device` event.
**Note:** These two events only fire until the callback from `select-usb-device`
is called. They are not intended to be used as a generic usb device listener.
* The [`usb-device-revoked' event on the Session](../api/session.md#event-usb-device-revoked) can
be used to respond when [device.forget()](https://developer.chrome.com/articles/usb/#revoke-access)
is called on a USB device.
* [`ses.setDevicePermissionHandler(handler)`](../api/session.md#sessetdevicepermissionhandlerhandler)
can be used to provide default permissioning to devices without first calling
for permission to devices via `navigator.usb.requestDevice`. Additionally,
the default behavior of Electron is to store granted device permission through
the lifetime of the corresponding WebContents. If longer term storage is
needed, a developer can store granted device permissions (eg when handling
the `select-usb-device` event) and then read from that storage with
`setDevicePermissionHandler`.
* [`ses.setPermissionCheckHandler(handler)`](../api/session.md#sessetpermissioncheckhandlerhandler)
can be used to disable USB access for specific origins.
### Example
This example demonstrates an Electron application that automatically selects
USB devices (if they are attached) through [`ses.setDevicePermissionHandler(handler)`](../api/session.md#sessetdevicepermissionhandlerhandler)
and through [`select-usb-device` event on the Session](../api/session.md#event-select-usb-device)
when the `Test WebUSB` button is clicked.
```javascript fiddle='docs/fiddles/features/web-usb'
```