Clerk Ruby SDK

Create a Clerk application

You need to create a Clerk application in your Clerk Dashboard before you can set up Clerk Ruby. For more information, check out our Set up your application guide.

Install Ruby

Once a Clerk application has been created, you can install and then start using Clerk Ruby in your application.

Add this line to your application's Gemfile.

gem 'clerk-sdk-ruby', require: "clerk"

And then execute:

$ bundle install

Or install it yourself as:

$ gem install clerk-sdk-ruby

Instantiate a Clerk::SDK instance

To access all Backend API endpoints, you need to instantiate a Clerk::SDK instance.

You will need your Clerk secret key to instantiate an instance. Go to the Clerk Dashboard and navigate to the API Keys page and copy your secret key.

This examples shows how to instantiate an instance of Clerk::SDK with your secret key and then send your first user a welcome email.

clerk = `YOUR_SECRET_KEY`)

# List all users

# Get your first user
user = clerk.users.all(limit: 1).first

# Extract their primary email address ID
email_id = user["primary_email_address_id"]

# Send them a welcome email
    email_address_id: email_id,
    from_email_name: "welcome",
    subject: "Welcome to MyApp",
    body: "Welcome to MyApp, #{user["first_name"]}",


The SDK can be configured in three ways: environment variables, configuration singleton and constructor arguments. The priority goes like this:

  • Constructor arguments
  • Configuration object
  • Environment variables

Constructor arguments

You can customize each instance of the Clerk::SDK object by passing keyword arguments to the constructor:

clerk =
    api_key: `YOUR_SECRET_KEY`,
    base_url: "Y",

Configuration object

If an argument is not provided, the configuration object is looked up, which falls back to the associated environment variable. Here's an example with all supported configuration settings their environment variable equivalents:

Clerk.configure do |c|
  c.api_key = `YOUR_SECRET_KEY` # if omitted: ENV["CLERK_SECRET_KEY"] - API calls will fail if unset
  c.base_url = "https://..." # if omitted: ""
  c.logger = # if omitted, no logging
  c.middleware_cache_store = Rails.cache # if omitted: no caching

Refer to the Faraday documentation for details.

Environment variables

Here's a list of all environment variables the SDK uses:

Variable nameUsage
CLERK_API_BASEOverrides the default API base URL:
CLERK_SECRET_KEYThe Secret key of your instance (required)
CLERK_SIGN_IN_URLRails view helper: clerk_sign_in_url
CLERK_SIGN_IN_UPRails view helper: clerk_sign_up_url
CLERK_USER_PROFILE_URLRails view helper: clerk_user_profile_url


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