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Ruby with Rack

The Clerk Ruby SDK provides a Rack middleware to integrate Clerk into your Rack-based application.

Install clerk-sdk-ruby

The Clerk Ruby SDKRuby Icon provides a range of backend utilities to simplify user authentication and management in your application.

  1. Add the following code to your application's Gemfile.
    Gemfile
    gem 'clerk-sdk-ruby', require: "clerk"
  2. Run the following command to install the SDK:
    terminal
    $ bundle install

Configuration

The configuration object provides a flexible way to configure the SDK. When a configuration value is not explicitly provided, it will fall back to checking the corresponding environment variableRuby Icon. You must provide your Clerk Secret Key, which can be retrieved from the API keys page in the Clerk Dashboard.

The following example shows how to set up your configuration object:

Clerk.configure do |c|
  c.secret_key = `YOUR_SECRET_KEY` # if omitted: ENV["CLERK_SECRET_KEY"] - API calls will fail if unset
  c.logger = Logger.new(STDOUT) # if omitted, no logging
end

For more information, see Faraday's documentation.

Add Clerk's Rack middleware

Add the Clerk middleware to your Rack application by updating your config.ru file with the following code:

config.ru
require "rack"
require "clerk/rack"

require_relative "app"

use Clerk::Rack::Middleware
run App.new

Access the clerk object

Once you've added the middleware, you can access the clerk object in your actions and views. The clerk object provides access to the Ruby SDK's available methodsRuby Icon.

The following example demonstrates a simple Rack application that protects all routes. If the user is authenticated, it returns the user's first name and ID. If the user is not authenticated, it returns a 401 status code.

app.rb
require "erb"
require "clerk"

class App
  def call(env)
    clerk = env["clerk"]

    # Check if the user is authenticated
    user = clerk.user
    user ?
      [200, {"Content-Type" => "text/plain"}, ["Authenticated User: #{user.first_name} (#{user.id})"]]:
      [401, {"Content-Type" => "text/plain"}, ["Not Authenticated"]]
  end
end

Example: Reverification

The reverification feature provides an additional layer of security by requiring users to reverify their session before accessing sensitive routes.

There are two ways to handle reverification in a Rack application:

  1. In your middlewareRuby Icon
  2. In your application logicRuby Icon

In your middleware

To handle reverification in your Rack middleware, use the Clerk::Rack::Reverification middleware. It accepts an optional presetRuby Icon parameter to customize the reverification requirements and an optional routes parameter to specify which routes should be protected.

In the following example, the reverification preset is set to LAX and reverification is required for all routes that match the /* pattern.

config.ru
require "rack"
require "clerk/rack"

require_relative "app"

use Clerk::Rack::Middleware
# Reverification preset is set to `LAX`
use Clerk::Rack::Reverification,
  preset: Clerk::StepUp::Preset::LAX,
  routes: ["/*"]

run App.new

In your application logic

To handle reverification in your app logic,

  • Use the clerk.user_needs_reverification? method to check if the user needs to reverify their session, which accepts an optional presetRuby Icon parameter to customize the reverification requirements.
  • Use the clerk.user_reverification_rack_response method to get the response.

The following example demonstrates a simple Rack application that requires authentication and reverification for all routes.

app.rb
require "erb"
require "clerk"

STEP_UP_PRESET = Clerk::StepUp::Preset::LAX

class App
  def call(env)
    clerk = env["clerk"]

    # Check if the user needs to reverify their session
    if clerk.user_needs_reverification?(STEP_UP_PRESET)
      # Get the response
      return clerk.user_reverification_rack_response(STEP_UP_PRESET)
    end

    # Check if the user is authenticated
    user = clerk.user
    user ?
      [200, {"Content-Type" => "text/plain"}, ["Authenticated User: #{user.first_name} (#{user.id})"]]:
      [401, {"Content-Type" => "text/plain"}, ["Not Authenticated"]]
  end
end

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