Device

Read the current device, OS, and locale snapshot

One.Device returns a snapshot of the device running your app: model, operating system, form factor, simulator state, an app-scoped vendor id, and the effective locale, languages, calendar, time zone, and currency. It reads system APIs directly and never prompts for permission. For the installed app’s own version, build, and bundle ID, use One.AppInfo.

On iOS it reads UIDevice, Locale, and TimeZone. On Android it reads Build, Settings.Secure, and the default locale and time zone. On web the browser reports what it may: the platform string, Intl locale data, and preferred languages, with hardware identity left blank.

Usage

import { One } from 'one'

const info = await One.Device.getInfo()
console.log(info.model, info.systemName, info.systemVersion)

const locale = await One.Device.getLocalizationInfo()
console.log(locale.localeIdentifier, locale.timeZoneIdentifier)

Both calls are snapshots. For locale and calendar values that update with system changes, use Localization and its React hooks.

How it works

getInfo builds one object per call. On iOS the model is Apple’s device family string such as iPhone, not a retail model name, and the vendor identifier is identifierForVendor, which can be absent until after the user first unlocks the device and can change once all of a vendor’s apps are removed. On Android the model is Build.MODEL, the system name is Android, the version is the release string, and the vendor identifier is ANDROID_ID, scoped to the app signing key and never a hardware id. The interface idiom is phone, pad, tv, carPlay, mac, vision, or unspecified; Android reports tv for television, pad for smallest width 600dp and up, and phone otherwise. isSimulator tells the iOS simulator or an Android emulator apart from hardware.

getLocalizationInfo reads the effective locale as a BCP 47 tag, the preferred language tags, the calendar identifier, the time zone identifier, the current UTC offset in seconds (positive east of UTC, reflecting daylight saving time at the moment of the call), and the currency code when the platform exposes one. On web the locale, calendar, and time zone come from Intl.DateTimeFormat, languages from navigator.languages, and currency stays absent since browsers do not expose the user’s chosen currency. Server rendering returns empty strings, empty language lists, a zero offset, and no currency.

API reference

Platform differences

Limits and gotchas

• The vendor id is not an account id. It can change after reinstalls and may be absent before first unlock. Scope accounts to your own issued identity instead.
• Snapshots go stale. Locale, time zone, and offset are read fresh per call. Re-read after the app returns from the background if you format with them.
• The model is not a retail name. iOS reports the family only, so do not parse it for hardware capabilities.
• Web hides hardware. Model, version, vendor id, and simulator state are blank by browser design, not by bug.

Examples

import { useEffect, useState } from 'react'
import { One } from 'one'

function useIsPad() {
  const [isPad, setIsPad] = useState(false)

  useEffect(() => {
    One.Device.getInfo().then((info) => {
      setIsPad(info.interfaceIdiom === 'pad')
    })
  }, [])

  return isPad
}

The idiom read happens once on mount, since the form factor cannot change under a running app. Phones and tablets then branch on one boolean.

import { useEffect, useState } from 'react'
import { Text } from 'react-native'
import { One } from 'one'

function LocalTime({ whenMs }: { whenMs: number }) {
  const [label, setLabel] = useState('')

  useEffect(() => {
    One.Device.getLocalizationInfo().then((locale) => {
      setLabel(
        new Intl.DateTimeFormat(locale.localeIdentifier, {
          timeZone: locale.timeZoneIdentifier,
          hour: 'numeric',
          minute: '2-digit',
        }).format(new Date(whenMs))
      )
    })
  }, [whenMs])

  return <Text>{label}</Text>
}

Formatting with the reported locale and zone keeps times consistent with the rest of the device, including daylight saving time at the moment of the call.