Biometry

The 💠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 method:

Variable

import { biometry } from '@telegram-apps/sdk';

biometry.isSupported(); // boolean

Functions

import { isBiometrySupported } from '@telegram-apps/sdk';

isBiometrySupported(); // 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. If errors occur, the mountError signal will reflect the error.

Variable

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

Functions

import {
  mountBiometry,
  isBiometryMounting,
  isBiometryMounted,
  biometryMountError,
} from '@telegram-apps/sdk';

if (mountBiometry.isAvailable()) {
  try {
    const promise = mountBiometry();
    isBiometryMounting(); // true
    await promise;
    isBiometryMounting(); // false
    isBiometryMounted(); // true
  } catch (err) {
    biometryMountError(); // equals "err"
    isBiometryMounting(); // false
    isBiometryMounted(); // false
  }
}

To unmount, use the unmount method:

Variable

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

Functions

import { unmountBiometry, isBiometryMounted } from '@telegram-apps/sdk';

unmountBiometry();
isBiometryMounted(); // 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.

Variable

if (biometry.requestAccess.isAvailable()) {
  const granted = await biometry.requestAccess(); // boolean
}

Functions

import { requestBiometryAccess } from '@telegram-apps/sdk';

if (requestBiometryAccess.isAvailable()) {
  const granted = await requestBiometryAccess(); // 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.

Variable

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

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

Functions

import { authenticateBiometry } from '@telegram-apps/sdk';

if (authenticateBiometry.isAvailable()) {
  const { status, token } = await authenticateBiometry({
    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.

Variable

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

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

Functions

import { updateBiometryToken } from '@telegram-apps/sdk';

if (updateBiometryToken.isAvailable()) {
  const updated = await updateBiometryToken({
    reason: 'Want to delete',
  });

  await updateBiometryToken({
    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.

Variable

if (biometry.openSettings.isAvailable()) {
  biometry.openSettings();
}

Functions

import { openBiometrySettings } from '@telegram-apps/sdk';

if (openBiometrySettings.isAvailable()) {
  openBiometrySettings();
}