app/controllers/application_controller.rb

@@ -30,6 +30,18 @@ class ApplicationController < ActionController::Base
 
   private
 
+  def validate_captcha!
+    Rails.logger.info("Captcha params: #{captcha_params}")
+
+    return if LibreCaptcha.new.valid?(id: captcha_params[:id], answer: captcha_params[:answer])
+
+    render json: { error: 'Incorrect CAPTCHA solution' }, status: :unprocessable_entity
+  end
+
+  def captcha_params
+    params.expect(captcha: [:id, :answer])
+  end
+  
   def default_url_options(options = {})
     options.merge(path_params: { slug: ActsAsTenant.current_tenant&.slug })
   end

app/controllers/users/registrations_controller.rb

@@ -4,6 +4,8 @@ class Users::RegistrationsController < Devise::RegistrationsController
   clear_respond_to 
   respond_to :json
 
+  before_action :validate_captcha!, only: :create
+
   def create
     wedding = Wedding.create(wedding_params)
     unless wedding.persisted?

app/services/libre_captcha.rb

@@ -11,4 +11,10 @@ class LibreCaptcha
       }.to_json
     ).then { |raw| JSON.parse(raw)['id'] }
   end
+
+  def valid?(id:, answer:)
+    HTTParty.post("http://libre-captcha:8888/v2/answer",
+      body: { id:, answer: }.to_json
+    ).then { |raw| JSON.parse(raw)['result'] == 'True' }
+  end
 end

spec/requests/captcha_spec.rb

@@ -14,8 +14,8 @@ RSpec.describe 'captcha', type: :request do
         schema type: :object,
         required: %i[id], 
         properties: {
-          id: { type: :string, format: :uuid }
-          media_url: { type: :string, format: :uri }
+          id: { type: :string, format: :uuid },
+          media_url: { type: :string, format: :uri },
         }
         xit
       end

spec/requests/schemas.rb

@@ -18,5 +18,16 @@ module Swagger
       example: :default,
       description: 'Wedding slug'
     }
+
+    CAPTCHA = {
+      captcha: {
+        type: :object,
+        required: %i[id answer],
+        properties: {
+          id: { type: :string, format: :uuid },
+          answer: { type: :string }
+        }
+      }
+    } 
   end
 end

spec/requests/users/registrations_spec.rb

@@ -30,7 +30,8 @@ RSpec.describe 'users/registrations', type: :request do
             properties: {
               date: { type: :string, format: :date},
             }
-          }
+          },
+          **Swagger::Schema::CAPTCHA
         }
       }