The Write Hook, which runs anytime you create or update a user, allows you to do things like:
  • Changing the user’s password
  • Changing the user’s email address
  • Updating the user’s profile
You can also use the Write Hook to automatically set default values for newly-created users. For example, you might want to automatically assign a user to the same group, department, or vendor as the ones to which you’ve been assigned.
Auth0 only supports user creation with Database Connections.

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Hook contract

  • ctx: Context object.
    • request.originalUser: Current user’s values where the payload is the new set of fields. Only available when the method is update.
    • payload: Payload object
      • memberships: Array of memberships that were selected in the UI when creating the user.
      • email: Email address of the user.
      • password: Password of the user.
      • connection: Name of the database connection.
      • app_metadata: Data that’s included if a Custom Field being modified is saved in app_metadata.
      • user_metadata: Data that’s included if a Custom Field being modified is saved in user_metadata.
    • userFields: User fields array (if specified in the settings query)
    • method: Either create or update depending on whether this is being called as a result of a create or an update call.
  • callback(error, user): Callback to which you can return an error and the user object that should be sent to the .
For more information about userFields, read Delegated Administration: Settings Query Hook.

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Sample use

Kelly manages the Finance department. When she creates users, these users should be assigned as members of the Finance department. 
function(ctx, callback) {
  var newProfile = {
    email: ctx.payload.email,
    password: ctx.payload.password,
    connection: ctx.payload.connection,
    user_metadata: ctx.payload.user_metadata,
    app_metadata: {
      department: ctx.payload.memberships && ctx.payload.memberships[0],
      ...ctx.payload.app_metadata
    }
  };

  if (!ctx.payload.memberships || ctx.payload.memberships.length === 0) {
    return callback(new Error('The user must be created within a department.'));
  }

  // Get the department from the current user's metadata.
  var currentDepartment = ctx.request.user.app_metadata && ctx.request.user.app_metadata.department;
  if (!currentDepartment || !currentDepartment.length) {
    return callback(new Error('The current user is not part of any department.'));
  }

  // If you're not in the IT department, you can only create users within your own department.
  // IT can create users in all departments.
  if (currentDepartment !== 'IT' && ctx.payload.memberships[0] !== currentDepartment) {
    return callback(new Error('You can only create users within your own department.'));
  }

  if (ctx.method === 'update') {
    // If updating, only set the fields we need to send
    Object.keys(newProfile).forEach(function(key) {
      if (newProfile[key] === ctx.request.originalUser[key]) delete newProfile[key];
    });
  }

  // This is the payload that will be sent to API v2. You have full control over how the user is created in API v2.
  return callback(null, newProfile);
}

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