Auther provides simple, form-based authentication for apps that need security but don’t want to deal with the clunky HTTP Basic Authentication user interface or as heavyweight as Devise. Auther doesn’t require a database and is compatible with password managers which makes for a pleasant user experience.

Auther is useful in situations — like minimal viable products or applications with a small user base — where you need to a security layer up and running quickly before adding more robust user management.


  • Supports form-based authentication compatible with password managers like Bitwarden.

  • Uses pure CSS for styling.

  • Uses encrypted account credentials to keep sensitive information secure.

  • Supports multiple accounts with optional path exclude lists.

  • Supports customizable routes, models, presenters, views, controllers, and loggers.

  • Provides a generator for easy install and setup within an existing project.

  • Provides auto-redirection to requested path for verified credentials.


Form Without Errors Screenshot
Form With Errors Screenshot



To install with security, run:

# 💡 Skip this line if you already have the public certificate installed.
gem cert --add <(curl --compressed --location
gem install auther --trust-policy HighSecurity

To install without security, run:

gem install auther

You can also add the gem directly to your project:

bundle add auther

Once the gem is installed, you only need to require it:

require "auther"

Run the credentials generator to generate credentials for your application:

rails generate auther:credentials


Credentials Generator Screenshot

If using direnv, copy and paste the generated credentials — as shown above — into your .envrc file (💡 don’t forget to add export before each key). Ensure you’ve applied these credentials to your environment and then run the install generator to configure and initialize your application:

rails generate auther:install

💡 If you ran the generator before applying your credentials to the environment, you can re-run the generator to fix.


Launch your Rails application and visit the following: http://localhost:3000/login. Enter your login and password as used for the rails generate auther:credentials generator and you’ll be logged in.


The initializer (installed during setup) can be found here: config/initializers/auther.rb. The initializer comes installed with the following settings:

Rails.application.config.auther = {
  accounts: [
      name: "admin",
      encrypted_login: ENV["AUTHER_ADMIN_LOGIN"],
      encrypted_password: ENV["AUTHER_ADMIN_PASSWORD"],
      paths: ["/admin"]
  secret: ENV["AUTHER_SECRET"]

To encrypt/decrypt account credentials, launch a rails console and run the following:

# The secret as defined in `Rails.application.config.auther` and/or produced by the credentials generator.
secret = SecureRandom.hex 16 # "426a7f46548a1a4518676a8e246517d8"

# The cipher for encrypting/decrypting values.
cipher = secret

# Use the following to encrypt an unencrypted value.
cipher.encrypt ""

# Use the following to decrypt an encrypted value.
cipher.decrypt "hWToltdpl+uZJBPELKNC7Ij++jPkTuo=--nEdbOYL9fIRh14hY--fU+VSCd4+DDOhOmG1gzRfQ=="

The initializer can be customized as follows:

  • title - Optional. The HTML page title (as rendered within a browser tab). Default: "Authorization".

  • label - Optional. The page label (what would appear above the form). Default: "Authorization".

  • secret - Required. The secret passphrase used to encrypt/decrypt account credentials.

  • accounts - Required. The array of accounts with different or similar access to the application.

    • name - Required. The account name that uniquely identifies the account.

    • encrypted_login - Required. The encrypted account login.

    • encrypted_password - Required. The encrypted account password.

    • paths - Required. The array of excluded paths for which only this account has access to.

    • authorized_url - Optional. The URL to redirect to upon successful authorization. Authorized redirection works in the order defined:

      • The excluded path (if requested prior to authorization but now authorized).

      • The authorized URL (if defined and the excluded path wasn’t requested).

      • The root path (if none of the above).

    • deauthorized_url - Optional. The URL to redirect to upon successful deauthorization (i.e. logout). Deauthorized redirections works as follows (in the order defined):

      • The deauthorized URL (if defined).

      • The auth URL.

  • url - Optional. The URL to redirect to when enforcing authentication. Default: "/login".

  • logger - Optional. The logger used to log path/account authorization messages. Default: nil.


The routes can be customized as follows (installed, by default, via the install generator):

Rails.application.routes.draw do
  mount Auther::Engine => "/auther"
  get "/login", to: "auther/session#new", as: "login"
  delete "/logout", to: "auther/session#destroy", as: "logout"


The Auther::Account is a struct that uses ActiveModel validations to aid in attribute validation. This model could potentially be replaced with a database-backed object (would require controller customization)…​but you should question if you have outgrown the use of this gem and need a different solution altogether if it comes to that.


The Auther::Presenter::Account is a plain old Ruby object that uses ActiveModel validations to aid in form validation. This presenter makes it easy to construct form data for input and validation.


The view can be customized by creating the following file within your Rails application (assumes that the default Auther::SessionController implementation is sufficient): app/views/auther/session/new.html.

The form uses the @account instance variable which is an instance of the Auther::Presenter::Account presenter (as mentioned above). The form can be stylized by modifying the styles found in the auther.scss stylesheet.


The Auther::SessionController inherits from the Auther::BaseController. To customize, it is recommended that you add a controller to your app that inherits from the Auther::BaseController. Example:

# Example Path:  app/controllers/session_controller.rb
class SessionController < Auther::BaseController
  layout "example"

This allows customization of session controller behavior to serve any special business needs. See the Auther::BaseController for additional details or the Auther::SessionController for default implementation.


As mentioned in the setup above, the logger can be customized as follows:

# This is the default logger silences all logging attempts. nil

# Can be used to log to the environment log. "log/#{Rails.env}.log"

# Can be used to log to standard output. STDOUT

When logging is enabled, you’ll be able to see the following information in the server logs to help debug custom Auther settings:

  • Requested path and excluded path detection.

  • Finding (or not finding) of account.

  • Account authentication pass/fail.

  • Account and path authorization pass/fail.


  • If upgrading Rails, changing the cookie/session settings, generating a new secret base key, etc. this might cause Auther authentication to fail. Make sure to clear your browser cookies in this situation or use Google Chrome (incognito mode) to verify.

  • If the authentication view/form looks broken (style wise) this could be due to custom ActionView::Base.field_error_proc settings defined by your app (usually via an initializer). Auther uses this configuration ActionView::Base.field_error_proc = proc { |html_tag, _| html_tag.html_safe } so that no additional markup is added to the DOM when errors are raised. If you have customized this to something else, you might want to read the usage documentation (mentioned above) to rebuild the authentication view/form for your specific business needs.


To contribute, run:

git clone
cd auther

You can also use the IRB console for direct access to all objects:



To test, run: