Each follows the same rule as the camera: use the web API where the host has one, and only cross the bridge where it does not. One call per capability hides that difference:

await soli.nativeBridge.vibrate(200)
await soli.nativeBridge.share({ title: "Bonfire", text: "Look at this", url: location.href })
await soli.nativeBridge.badge(3)
await soli.nativeBridge.keepAwake(true)
const ok  = await soli.nativeBridge.authenticate("Confirm the payment")
const tag = await soli.nativeBridge.readTag()

Feature-detect first — a capability is listed only where it actually works:

if (soli.nativeBridge.supports("nfc")) { ... }

What each does

Every call returns a promise. Ones that need a human — biometrics, NFC, sharing — resolve when they answer and reject when they cancel, so a page never waits forever:

try {
  await soli.nativeBridge.authenticate("Confirm the transfer")
  submit()
} catch (err) {
  if (err.name === "TimeoutError") retry()
  else showMessage(err.message)      // "cancelled", "NFC is switched off", …
}

The honest limits

Four rows above are not oversights, and each fails for a different reason:

• Android has no arbitrary badge counter. iOS, macOS and the web let you set the icon to any number at any time; Android does not — a badge there is a byproduct of a notification. badge(n) posts a silent, minimum-importance carrier notification carrying setNumber(n): launchers that render a count (Samsung and others) show the number, stock/Pixel shows a dot, and the carrier sits collapsed at the bottom of the shade. badge(0) cancels it.
• Macs have no NFC radio. Not a missing binding — the hardware is absent.
• macOS haptics mean the trackpad, and only Force Touch ones. A no-op elsewhere rather than an error, since a page asking to buzz should not have to care.
• Biometrics do not authenticate anything to your server. They confirm the person holding the device, locally. For an actual credential use WebAuthn — this is a lock on a UI action, not proof of identity.

Badges, open and closed

A badge has two cases, and Android and Apple differ in both.

While the app is open, badge(count) sets it — the dock tile on macOS, navigator.setAppBadge in a browser, the carrier notification on Android.

While the app is closed, the count has to ride the push, because nothing local is running to set it:

# iOS / macOS — aps.badge sets the icon number directly
Apns.send(token, { "title": "3 new", "badge": 3 }, apns_options)

# Android — notification_count on the pushed notification
Fcm.send(token, { "title": "3 new", "badge": 3 }, fcm_options)

# or let Push.deliver route it to whichever the user has
Push.deliver("user:#{str(user.id)}", { "title": "3 new", "badge": 3 }, options)

badge is pulled out of the payload and placed correctly for each transport — aps.badge for APNs, android.notification.notification_count for FCM — so the same call badges a closed app on either platform. On the web, the count arrives as push data and your service worker calls navigator.setAppBadge (that part is app-side, in sw.js).

Vibration patterns

A number is a duration; an array alternates on and off, in milliseconds:

soli.nativeBridge.vibrate(50)                 // a tick
soli.nativeBridge.vibrate([0, 100, 50, 100])  // buzz, pause, buzz

WebKit has no Vibration API at all, so on macOS this is the bridge or nothing.

NFC

Android only, and it reads the tag's id:

const id = await soli.nativeBridge.readTag()   // "04a2b3c4d5e6f7"

The shell uses reader mode, not foreground dispatch: it does not bounce through a new intent, and it suppresses the system's discovery sound and activity switch — which is what makes an in-app scanner feel in-app rather than like the OS interrupting.

Web NFC exists only in Chrome for Android, never in a WebView, so there is no fallback to reach for.

Printing

await soli.nativeBridge.print()

Android needs the bridge — a WebView ignores window.print() entirely. Everywhere else this is window.print(), which is why the call exists at all rather than leaving pages to branch.

Related

• Camera & Microphone · Scanning · Geolocation
• Native Bridge — the capability table