Using custom UIs - Privy docs

By default, Privy’s wallet MFA feature will use Privy’s UIs for enrolling users in MFA, managing MFA methods, and having users complete MFA to authorize signatures and transactions for the embedded wallet.

This section is intended only for apps that would like to use wallet MFA with their own custom UIs, instead of Privy’s defaults.

Implementing wallet MFA with custom UIs is substantially more involved than integrating Privy’s out-of-the-box wallet MFA feature. Make sure to consider the development trade-offs of using custom UIs over Privy defaults before finalizing on your approach!

Configuring MFA to be used with custom UIs

If you plan to use your own custom UIs for wallet MFA, set the mfa.noPromptOnMfaRequired field to true in the Privy provider.

function MyApp({Component, pageProps}: AppProps) {
  return (
    <>
      <PrivyProvider
        appId={process.env.NEXT_PUBLIC_PRIVY_APP_ID}
        config={{
          mfa: {
            // Defaults to 'false'
            noPromptOnMfaRequired: true,
          },
          ...insertTheRestOfYourConfig,
        }}
      >
        <Component {...pageProps} />
      </PrivyProvider>
    </>
  );
}

This will configure Privy to not show its default UIs for wallet MFA, and instead rely on your custom implementation.

Enrolling in MFA

To enroll your users in MFA, use the hook from Privy. Currently, users can enroll in three MFA methods:

SMS, where users authenticate with a 6-digit MFA code sent to their phone number
TOTP, where users authenticate with a 6-digit MFA code from an authentication app, like Authy or Google Authenticator
Passkey, where users verify with a previously registered passkey, generally through biometric authentication on their device

SMS

To enroll your users in MFA with SMS, use the and methods returned by the hook:

const {initEnrollmentWithSms, submitEnrollmentWithSms} = useMfaEnrollment();

First, initiate enrollment by prompting your user to enter the phone number they’d like to use for MFA. Then, call Privy’s method. As a parameter to this , pass a JSON object with a field that contains the user’s provide phone number as a string.

// Prompt the user for their phone number
const phoneNumberInput = 'insert-phone-number-from-user';
// Send an enrollment code to their phone number
await initEnrollmentWithSms({phoneNumber: phoneNumberInput});

Once is called with a valid , Privy will then send a 6-digit MFA enrollment code to the provided number. This method returns a Promise that will resolve to void if the code was successfully sent, or will reject with an error if there was an error sending the code (e.g. invalid phone number).

Next, prompt the user to enter the 6-digit code that was sent to their phone number, and use the method to complete enrollment of that phone number. As a parameter to , you must pass a JSON object with both the original that the user enrolled, and the they received at that number.

// Prompt the user for the code sent to their phone number
const mfaCodeInput = 'insert-mfa-code-received-by-user';
await submitEnrollmentWithSms({
  phoneNumber: phoneNumberInput, // From above
  mfaCode: mfaCodeInput,
});

The component below serves as a reference implementation for how to enroll your users in MFA with SMS!

Example enrolling a phone number for MFA
import {useMfaEnrollment} from '@privy-io/react-auth';

export default function MfaEnrollmentWithSms() {
  const {initEnrollmentWithSms, submitEnrollmentWithSms} = useMfaEnrollment();

  const [phoneNumber, setPhoneNumber] = useState<string | null>(null);
  const [mfaCode, setMfaCode] = useState<string | null>(null);
  const [pendingMfaCode, setPendingMfaCode] = useState<boolean>(false);

  // Handler for when the user enters their phone number to enroll in MFA.
  const onEnteredPhoneNumber = () => {
    await initEnrollmentWithSms({phoneNumber: phoneNumber}); // Sends an MFA code to the `phoneNumber`
    setPendingMfaCode(true);
  }

  // Handler for when the user enters the MFA code sent to their phone number.
  const onEnteredMfaCode = () => {
    await submitEnrollmentWithSms({phoneNumber: phoneNumber, mfaCode: mfaCode});
    // See the "Handling errors with code submission" section of this guide
    // for details on how to handle errors raised by `submitEnrollmentWithSms`
    setPendingMfaCode(false);
  }

  // If no MFA code has been sent yet, prompt the user for their phone number to enroll
  if (!pendingMfaCode) {
    // Input field for the user to enter the phone number they'd like to enroll for MFA
    return <>
      <input placeholder='(555) 555 5555' onChange={(event) => setPhoneNumber(event.target.value)}/>
      <button onClick={onEnteredPhoneNumber}>Enroll a Phone with MFA</button>
    </>;
  }

  // Input field for the user to enter the MFA code sent to their phone number
  return <>
    <input placeholder='123456' onChange={(event) => setMfaCode(event.target.value)}/>
    <button onClick={onEnteredMfaCode}>Submit Enrollment Code</button>
  </>;
}

If your app has enabled SMS as a possible login method, users will not be able to enroll SMS as a valid MFA method.

SMS must be either be used as a login method to secure user accounts, or as an MFA method for additional security on the users’ wallets.

TOTP

To enroll your users in MFA with TOTP, use the and methods returned by the hook:

const {initEnrollmentWithTotp, submitEnrollmentWithTotp} = useMfaEnrollment();

First, initiate enrollment by calling Privy’s method with no parameters. This method returns a Promise for an and that the user will need in order to complete enrollment.

const {authUrl, secret} = await initEnrollmentWithTotp();

Then, to have the user enroll, you can either:

display the TOTP as a QR code to the user, and prompt them to scan it with their TOTP client (commonly, a mobile app like Google Authenticator or Authy)
allow the user to copy the TOTP and paste it into their TOTP client

You can directly pass in the from above into a library like to render the URL as a QR code to your user.

Once your user has successfully scanned the QR code, an enrollment code for Privy will appear within their TOTP client. Prompt the user to enter this code in your app, and call Privy’s method. As a parameter to , pass a JSON object with an field that contains the MFA code from the user as a string.

const mfaCodeInput = 'insert-mfa-code-from-user-totp-app'; // Prompt the user for the code in their TOTP app
await submitEnrollmentWithTotp({mfaCode: mfaCodeInput});

The component below serves as a reference implementation for how to enroll your users in MFA with TOTP!

Example enrolling a TOTP client for MFA
import {useMfaEnrollment} from '@privy-io/react-auth';
import QRCode from 'react-qr-code';
import {CopyableElement} from '../components/CopyableElement';

export default function MfaEnrollmentWithTotp() {
  const {initEnrollmentWithTotp, submitEnrollmentWithTotp} = useMfaEnrollment();
  const [totpAuthUrl, setTotpAuthUrl] = useState<string | null>(null);
  const [totpSecret, setTotpSecret] = useState<string | null>(null);
  const [mfaCode, setMfaCode] = useState<string | null>(null);

  // Handler for when the user is ready to enroll in TOTP MFA
  const onGenerateTotpUrl = async () => {
    const {authUrl, secret} = await initEnrollmentWithTotp();
    setTotpAuthUrl(authUrl);
    setTotpSecret(secret);
  }

  // Handler for when the user enters the MFA code from their TOTP client
  const onEnteredMfaCode = async () => {
    await submitEnrollmentWithTotp({mfaCode: mfaCode});
    // See the "Handling errors with code submission" section of this guide
    // for details on how to handle errors raised by `submitEnrollmentWithTotp`
  }

  return(
    <div>
      {/* QR code for the user to scan */}
      {totpAuthUrl && totpSecret ?
        {/* If TOTP values have been generated... */}
        <>
          {/* ...show the user a QR code with the `authUrl` that they can scan...  */}
          <QRCode value={totpAuthUrl} />
          {/* ...or give them the option to copy the `secret` into their TOTP client  */}
          <CopyableElement value={totpSecret} />
        </> :
        {/* Else, show a button to generate the totpAuthUrl */}
        <button onClick={() => onGenerateTotpUrl()}>Show QR Code</button>
      }
      {/* Input field for the user to enter their MFA code */}
      <p>Enter the code from your authenticator app below.</p>
      <input placeholder='123456' onChange={(event) => setMfaCode(event.target.value)}/>
      <button onClick={() => submitEnrollmentWithTotp({mfaCode: mfaCode})}>Submit Enrollment Code</button>
    </div>
  );
}

Passkey

In order to use passkeys as a MFA method, make sure a valid passkey is linked to the user. You can set this up by following the steps here!

To enroll your users in MFA with passkeys, use the and methods returned by the hook:

const {initEnrollmentWithPasskey, submitEnrollmentWithPasskey} = useMfaEnrollment();

First, initiate enrollment by calling Privy’s method with no parameters. This method returns a Promise that will resolve to void indicating success.

await initEnrollmentWithPasskey();

Then, to have the user enroll, you must call Privy’s submitEnrollmentWithPasskey method with a list of the user’s passkey account credentialIds. You can find this list by querying the user’s linkedAccounts array for all accounts of type: 'passkey':

const {user} = usePrivy();

// ...

const credentialIds = user.linkedAccounts
  .filter((account): account is PasskeyWithMetadata => account.type === 'passkey')
  .map((x) => x.credentialId);

await submitEnrollmentWithPasskey({credentialIds});

The component below serves as a reference implementation for how to enroll your users in MFA with passkeys!

Example enrolling passkeys for MFA
import {useMfaEnrollment} from '@privy-io/react-auth';

export default function MfaEnrollmentWithPasskey() {
  const {user} = usePrivy();
  const {initEnrollmentWithPasskey, submitEnrollmentWithPasskey} = useMfaEnrollment();

  const handleEnrollmentWithPasskey = async () => {
    await initEnrollmentWithPasskey();

    const credentialIds = user.linkedAccounts
      .filter((account): account is PasskeyWithMetadata => account.type === 'passkey')
      .map((x) => x.credentialId);

    await submitEnrollmentWithPasskey({credentialIds});
  };

  return (
    <div>
      <div>Enable your passkeys for MFA</div>
      {user.linkedAccounts
        .filter((account): account is PasskeyWithMetadata => account.type === 'passkey')
        .map((account) => (
          <div key={account.id}>{account.credentialId}</div>
        ))}
      <button onClick={handleEnrollmentWithPasskey}>Enroll</button>
    </div>
  );
}

Completing MFA

Once users have successfully enrolled in MFA with Privy, they will be required to complete MFA whenever the private key for their embedded wallet must be used. This includes signing messages and transactions, recovering the embedded wallet on new devices, exporting the wallet’s private key, and setting a password on the wallet.

To ensure users can complete MFA when required, your app must do the following:

Set up a flow to guide the user through completing MFA when required.
Register an event listener to configure Privy to invoke the flow from step (1) whenever MFA is required.

Once a user has completed MFA on a given device, they can continue to use the wallet on that device without needing to complete MFA for 15 minutes.

After 15 minutes have elapsed, Privy will require that the user complete MFA again to re-authorize use of the wallet’s private key.

Guiding the user through MFA

To set up a flow to have the user complete MFA, use Privy’s hook.

const {init, submit, cancel} = useMfa();

This flow has three core components:

Requesting an MFA code be sent to the user’s MFA method ()
Submitting the MFA code provided by the user ()
Cancelling an in-progress MFA flow ()

Requesting an MFA challenge

To request an MFA challenge for the current user, call the method from the hook, passing the user’s desired MFA method ('sms', 'totp', or 'passkey') as a parameter.

const selectedMfaMethod = 'sms'; // Must be 'sms', 'totp' or 'passkey'
await init(selectedMfaMethod);

The method will then prepare an MFA challenge for the desired MFA method, and returns a Promise that resolves if the challenge was successfully created, and rejects with an error if there was an issue.

If the MFA method is 'sms', the user will receive an SMS with their MFA code at the phone number they originally enrolled.
If the MFA method is 'totp', the user will receive the MFA code within their authenticator app.
If the MFA method is 'passkey', init will return an object with options to pass to the native passkey system

Submitting the MFA verification

Once has resolved successfully, prompt the user to get their MFA code from their MFA method and to enter it within your app. Then, call the method from . As parameters to , pass the MFA method being used ('sms' or 'totp') and the MFA code that the user entered.

const mfaCode = 'insert-mfa-code-from-user';
await submit(selectedMfaMethod, mfaCode);

Cancelling the MFA flow

After has been called and the corresponding call has not yet occurred, the user may cancel their in-progress MFA flow if they wish.

To cancel the current MFA flow, call the method from the hook.

cancel();

To simplify the implementation, we recommend abstracting the logic above into a self-contained component that can be used whenever the user needs to complete an MFA flow.

For instance, you might write an MFAModal component that allows the user to (1) select their desired method of their enrolled MFA methods, (2) request an MFA code, and (3) submit the MFA code to Privy for verification. A sample implementation is below:

Example modal for guiding users through the MFA flow
import Modal from 'react-modal';

import {
  useMfaEnrollment,
  errorIndicatesMfaVerificationFailed,
  errorIndicatesMfaMaAttempts,
  errorIndicatesMfaTimeout,
  MfaMethod,
} from '@privy-io/react-auth';

type Props = {
  // List of available MFA methods that the user has enrolled in
  mfaMethods: MfaMethod[];
  // Boolean indicator to determine whether or not the modal should be open
  isOpen: boolean;
  // Helper function to open/close the modal */
  setIsOpen: (isOpen: boolean) => void;
};

export const MFAModal = ({mfaMethods, isOpen, setIsOpen}: Props) => {
  const {init, submit, cancel} = useMfa();
  // Stores the user's selected MFA method
  const [selectedMethod, setSelectedMethod] = useState<MfaMethod | null>(null);
  // Stores the user's MFA code
  const [mfaCode, setMfaCode] = useState('');
  // Stores the options for passkey MFA
  const [options, setOptions] = useState(null);
  // Stores an error message to display
  const [error, setError] = useState('');

  // Helper function to request an MFA code for a given method
  const onMfaInit = async (method: MfaMethod) => {
    const response = await init(method);
    setError('');
    setSelectedMethod(method);
    if (method === 'passkey') {
      setOptions(response);
    }
  };

  // Helper function to submit an MFA code to Privy for verification
  const onMfaSubmit = async () => {
    try {
      if (selectedMethod === 'passkey') {
        await submit(selectedMethod, options);
      } else {
        await submit(selectedMethod, mfaCode);
      }
      setSelectedMethod(null); // Clear the MFA flow once complete
      setIsOpen(false); // Close the modal
    } catch (e) {
      // Handling possible errors with MFA code submission
      if (errorIndicatesMfaVerificationFailed(e)) {
        setError('Incorrect MFA code, please try again.');
        // Allow the user to re-enter the code and call `submit` again
      } else if (errorIndicatesMfaMaxAttempts(e)) {
        setError('Maximum MFA attempts reached, please request a new code.');
        setSelectedMethod(null); // Clear the MFA flow to allow the user to try again
      } else if (errorIndicatesMfaTimeout(e)) {
        setError('MFA code has expired, please request a new code.');
        setSelectedMethod(null); // Clear the MFA flow to allow the user to try again
      }
    }
  };

  // Helper function to clean up state when the user closes the modal
  const onModalClose = () => {
    cancel(); // Cancel any in-progress MFA flows
    setIsOpen(false);
  };

  return (
    <Modal isOpen={isOpen} onAfterClose={onModalClose}>
      {/* Button for the user to select an MFA method and request an MFA code */}
      {mfaMethods.map((method) => (
        <button onClick={() => onMfaInit(method)}>Choose to MFA with {method}</button>
      ))}
      {/* Input field for the user to enter their MFA code and submit it */}
      {selectedMethod && selectedMethod !== 'passkey' && (
        <div>
          <p>Enter your MFA code below</p>
          <input placeholder="123456" onChange={(event) => setMfaCode(event.target.value)} />
          <button onClick={() => onMfaSubmit()}>Submit Code</button>
        </div>
      )}
      {/* Display error message if there is one */}
      {!!error.length && <p>{error}</p>}
    </Modal>
  );
};

Notice how the modal contains all logic for requesting the MFA code, submitting the MFA code, handling errors, and cancelling an in-progress MFA code.

Then, when your app needs to prompt a user to complete MFA, they can simply display this component and configure the prop with the list of MFA methods that are available for the current user.

Registering an event listener

Once you’ve set up your app’s logic for guiding a user to complete MFA, you lastly need to configure Privy to invoke this logic whenever MFA is required by the user’s embedded wallet.

To set up this configuration, use Privy’s hook. As a parameter to , you must pass a JSON object with an callback, described below.

onMfaRequired

Privy will invoke the callback you set whenever the user is required to complete MFA to use the embedded wallet. When this occurs, any use of the embedded wallet will be “paused” until the user has successfully completed MFA with Privy.

In this callback, you should invoke your app’s logic for guiding through completing MFA (done via the hook, as documented above). Within this callback, you can also access an parameter that contains a list of available MFA methods that the user has enrolled in ('sms' and/or 'totp' and/or 'passkey').

MFAProvider.tsx
import {useRegisterMfaListener, MfaMethod} from '@privy-io/react-auth';

import {MFAModal} from '../components/MFAModal';

export const MFAProvider = ({children}: {children: React.ReactNode}) => {
  const [isMfaModalOpen, setIsMfaModelOpen] = useState(false);
  const [mfaMethods, setMfaMethods] = useState<MfaMethod[]>([]);

  useRegisterMfaListener({
    // Privy will invoke this whenever the user is required to complete MFA
    onMfaRequired: (methods) => {
      // Update app's state with the list of available MFA methods for the user
      setMfaMethods(methods);
      // Open MFA modal to allow user to complete MFA
      setIsMfaModalOpen(true);
    },
  });

  return (
    <div>
      {/* This `MFAModal` component includes all logic for completing the MFA flow with Privy's `useMfa` hook */}
      <MFAModal isOpen={isMfaModalOpen} setIsOpen={setIsMfaModalOpen} mfaMethods={mfaMethods} />
      {children}
    </div>
  );
};

In order for Privy to invoke your app’s MFA flow, the component that calls Privy’s hook must be mounted whenever the user’s embedded wallet requires that they complete MFA.

In kind, we recommend that you render this component near the root of your application, so that it is always rendered whenever the embedded wallet may be used.

Handling errors with code submission

When both enrolling in and completing MFA, Privy sends a 6-digit code to the user’s selected MFA method, that the user must submit to Privy in order to verify their identity.

When submitting this MFA code, Privy may respond with an error if the code is incorrect, if the user has reached the maximum number of attempts for this MFA flow, or if the MFA flow has timed out. If the user enters in an incorrect code (e.g. by mistyping), the user is allowed to retry code submission up to a maximum of four attempts.

To simplify handling errors with MFA code submission, Privy provides the following helper functions to parse errors raised by the MFA code submission methods listed above. Each of these functions accepts the raw raised as a parameter, and returns a Boolean indicating if the error meets a certain condition:

: indicates the user entered an incorrect MFA code
indicates has reached the maximum number of attempts for this MFA flow, and that a new MFA code must be requested via
indicates that the current MFA code has expired, and that a new MFA code must be requested via

As an example, to handle errors raised by , you might use these helpers like so:

Handling errors during MFA code submission
try {
  // Errors from `submitEnrollmentWithSms` and `submitEnrollmentWithTotp` can be handled similarly
  await submit('insert-mfa-code', 'insert-mfa-method');
} catch (e) {
  if (errorIndicatesMfaVerificationFailed(e)) {
    console.error('Incorrect MFA code, please try again.');
    // Allow the user to re-enter the code and call `submit` again
  } else if (errorIndicatesMfaMaxAttempts(e)) {
    console.error('Maximum MFA attempts reached, please request a new code.');
    // Allow the user to request a new code with `init`
  } else if (errorIndicatesMfaTimeout(e)) {
    console.error('MFA code has expired, please request a new code.');
    // Allow the user to request a new code with `init`
  }
}

User authentication

Configuring MFA to be used with custom UIs

Enrolling in MFA

SMS

TOTP

Passkey

Completing MFA

Guiding the user through MFA

Requesting an MFA challenge

Submitting the MFA verification

Cancelling the MFA flow

Registering an event listener

onMfaRequired

Handling errors with code submission