💠Biometry

A component responsible for biometry functionality for Telegram Mini Apps.

Checking Support

To check if biometry is supported by the current Telegram Mini Apps version, use the isSupported signal:

import { biometry } from '@tma.js/sdk';

biometry.isSupported(); // boolean

Mounting

Before using the component, it must be mounted.

This process is asynchronous, as biometry data needs to be requested from the Telegram application. The isMounting signal will be set to true during the process and updated to false when complete.

If mounting is successful, the isMounted signal will be set to true.

try {
  const promise = biometry.mount();
  biometry.isMounting(); // true
  await promise;
  biometry.isMounting(); // false
  biometry.isMounted(); // true
} catch (err) {
  biometry.isMounting(); // false
  biometry.isMounted(); // false
}

To unmount, use the unmount method:

biometry.unmount();
biometry.isMounted(); // false

Requesting Biometry Access

To request biometry access, use the requestAccess method. It returns a promise with boolean value indicating whether access was granted by the user.

const isAccessGranted = await biometry.requestAccess(); // boolean

Authenticating

To authenticate a user and retrieve a previously saved token, use the authenticate method.

It optionally accepts an object with the following properties:

• reason?: string: a reason for authentication to display to the user.

The method returns an object with status ('failed' or 'authorized') and, if successful, a token: string.

const { status, token } = await biometry.authenticate({
  reason: 'Please!',
});

if (status === 'authorized') {
  console.log(`Authorized. Token: ${token}`);
} else {
  console.log('Not authorized');
}

Updating Token

To update the token stored in local secure storage, use the updateToken method.

The method accepts an optional object with the reason and token properties. If no token is provided, the existing token will be deleted.

It returns a promise with boolean indicating if any changes were made.

const updated = await biometry.updateToken({
  reason: 'Want to delete',
});

await biometry.updateToken({
  reason: 'Will set a new one',
  token: 'new token',
});

Opening Settings

To open the biometry-related settings modal, use the openSettings method. This method can only be triggered in response to user interaction.

biometry.openSettings();