What is the context.multifactor object?

On this page, we can see the following rule.

function guardianMultifactor(user, context, callback) {

  // run only for the specified clients
  //if (CLIENTS_WITH_MFA.indexOf(context.clientID) !== -1) {

  // uncomment the following if clause in case you want to request a second factor only from user's that have user_metadata.use_mfa === true
    //if (user.user_metadata && user.user_metadata.use_mfa){
      context.multifactor = {
        // required
        provider: 'guardian',

        // optional, defaults to true. Set to false to force Guardian authentication every time.
        // See https://auth0.com/docs/multifactor-authentication/custom#change-the-frequency-of-authentication-requests for details
        allowRememberBrowser: false

  callback(null, user, context);

What is the structure of context.multifactor? The documentation here only says that it " An object representing the multifactor settings used in implementing contextual MFA.", with a link to a more general, but not-helpful explanation of MFA.

Basically, I want to know:

  • What, specifically, is provider defining here? (ie. must use guardian vs shown guardian by default)
  • What other values can provider be set to? (ie. literal string must be one of this list: [“any”, “guardian”, …])
  • What other parameters can be set in multifactor?
  • What do they do?

I would like to know that myself.