Catch up on everything announced at Firebase Summit, and learn how Firebase can help you accelerate app development and run your app with confidence. Learn More

Manage Multi-factor Users

Stay organized with collections Save and categorize content based on your preferences.

This document shows you how to use the Firebase Admin SDK to manage your multi-factor users programmatically. When managing multi-factor users, you have access to an increased range of user properties compared to single-factor users.

Before you begin

Install the Node.js Admin SDK. Other Admin SDK languages are not currently supported.

Getting users

You can retrieve user multi-factor related data, such as a list of enrolled second factors, from the UserRecord object. To get a user record, call getUser() or getUserByEmail().

The example below shows a multi-factor enrolled user:

// console.log(userRecord.toJSON());
{
  uid: 'some-uid',
  displayName: 'John Doe',
  email: 'johndoe@gmail.com',
  photoURL: 'http://www.example.com/12345678/photo.png',
  emailVerified: true,
  phoneNumber: '+11234567890',
  // Set this user as admin.
  customClaims: {admin: true},
  // User with Google provider.
  providerData: [{
    uid: 'google-uid',
    email: 'johndoe@gmail.com',
    displayName: 'John Doe',
    photoURL: 'http://www.example.com/12345678/photo.png',
    providerId: 'google.com'
  }],
  multiFactor: {
    enrolledFactors: [
      // 2FA with SMS as 2nd factor.
      {
        uid: '53HG4HG45HG8G04GJ40J4G3J',
        phoneNumber: '+16505551234',
        displayName: 'Work phone',
        enrollmentTime: 'Fri, 22 Sep 2017 01:49:58 GMT',
        factorId: 'phone',
      },
    ],
  },
};

Listing users

The code below shows how to list all users and check if they have a secondary factor enrolled:

admin.auth().listUsers(1000, nextPageToken)
  .then((listUsersResult) => {
    listUsersResult.users.forEach((userRecord) => {
      // Multi-factor enrolled users second factors can be retrieved via:
      if (userRecord.multiFactor) {
        userRecord.multiFactor.enrolledFactors.forEach((enrolledFactor) => {
          console.log(userRecord.uid, enrolledFactor.toJSON());
        });
      }
    });
  })
  .catch((error) => {
    console.log('Error listing users:', error);
  });

Users are returned in batches, ordered by their uid. Each batch of results contains a list of users, and a next page token used to fetch the next batch. When all users have been listed, no pageToken is returned.

The maxResult field specifies the maximum batch size. The default and maximum value is 1000.

Creating a user

Call createUser() to create a new user. New users with secondary factors must have a verified email address (set emailVerified to true) and use a supported first factor to sign in. Up to 5 secondary factors are allowed per user.

The example shows how to create a new user with 2 secondary factors:

admin.auth().createUser({
  uid: '123456789',
  email: 'user@example.com',
  emailVerified: true,
  password: 'password',
  multiFactor: {
    enrolledFactors: [
      // When creating users with phone second factors, the uid and
      // enrollmentTime should not be specified. These will be provisioned by
      // the Auth server.
      // Primary second factor.
      {
        phoneNumber: '+16505550001',
        displayName: 'Corp phone',
        factorId: 'phone',
      },
      // Backup second factor.
      {
        phoneNumber: '+16505550002',
        displayName: 'Personal phone',
        factorId: 'phone'
      },
    ],
  },
})
.then((userRecord) => {
  console.log(userRecord.multiFactor.enrolledFactors);
})
.catch((error) => {
  console.log(error);
});

Updating a user

To update an existing user, call updateUser():

admin.auth().updateUser('123456789', {
  multiFactor: {
    enrolledFactors: [
      {
        // uid will be auto-generated.
        phoneNumber: '+16505550003',
        displayName: 'Spouse\'s phone',
        factorId: 'phone',
      },
      {
        // uid can also be specified. This is useful if a new second factor is added and an
        // existing enrolled second factor is kept unmodified.
        uid: 'existing-enrolled-mfa-uid',
        phoneNumber: '+16505550004',
        displayName: 'Personal phone',
        factorId: 'phone',
      },
      {
        phoneNumber: '+16505550005',
        displayName: 'Backup phone',
        factorId: 'phone',
        // Enrollment time can also be explicitly specified.
        enrollmentTime: new Date().toUTCString(),
      },
    ],
  },
})
.then((userRecord) => {
  console.log(userRecord.multiFactor.enrolledFactors);
})
.catch((error) => {
  console.log(error);
});

Adding a new secondary factor

Calling updateUser() with a list of enrolledFactors will erase any of the user's current secondary factors. To add a new secondary factor while preserving the existing ones, look up the user first, then add the new factor to the list:

function enrollSecondFactor(userId, secondFactorPhoneNumber, secondFactorDisplayName) {
  return admin.auth().getUser(userId)
    .then((userRecord) => {
      const updatedList = (userRecord.multiFactor &&
        userRecord.multiFactor.toJSON().enrolledFactors) || [];
      updatedList.push({
        phoneNumber: secondFactorPhoneNumber,
        displayName: secondFactorDisplayName,
        factorId: 'phone',
      });
      return admin.auth().updateUser(userRecord.uid, {
        multiFactor: {
          enrolledFactors: updatedList,
        },
      });
    })
    .catch((error) => {
      console.log(error);
    });
}

Removing a secondary factor

To completely unenroll a user from multi-factor authentication, set enrolledFactors to null or an empty array:

admin.auth().updateUser({
  uid: '123456789',
  multiFactor: {
    enrolledFactors: null,
  },
})
.then((userRecord) => {
  console.log(userRecord.multiFactor);
})
.catch((error) => {
  console.log(error);
});