diff --git a/.env.example b/.env.example
index f11568174..882dfe72f 100644
--- a/.env.example
+++ b/.env.example
@@ -2,3 +2,6 @@ ALLOWED_ORIGINS=localhost:3002,localhost:3000
 POSTGRES_HOST=changeme
 POSTGRES_USER=changeme
 POSTGRES_PASSWORD=changeme
+
+HYDRA_ADMIN_URL=http://docker.for.mac.localhost:9001
+HYDRA_SECRET=
diff --git a/Gemfile b/Gemfile
index abd0b4b80..cb2a7d483 100644
--- a/Gemfile
+++ b/Gemfile
@@ -6,6 +6,7 @@ git_source(:github) { |repo| "https://github.com/#{repo}.git" }
 ruby '3.0.3'
 
 gem 'bootsnap', require: false
+gem 'faraday'
 gem 'importmap-rails'
 gem 'jbuilder'
 gem 'pg', '~> 1.1'
@@ -32,4 +33,5 @@ end
 
 group :test do
   gem 'shoulda-matchers', '~> 5.0'
+  gem 'webmock'
 end
diff --git a/Gemfile.lock b/Gemfile.lock
index 246366e39..2ac248da0 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -60,6 +60,8 @@ GEM
       i18n (>= 1.6, < 2)
       minitest (>= 5.1)
       tzinfo (~> 2.0)
+    addressable (2.8.0)
+      public_suffix (>= 2.0.2, < 5.0)
     ast (2.4.2)
     bootsnap (1.9.3)
       msgpack (~> 1.0)
@@ -67,6 +69,8 @@ GEM
     byebug (11.1.3)
     coderay (1.1.3)
     concurrent-ruby (1.1.9)
+    crack (0.4.5)
+      rexml
     crass (1.0.6)
     diff-lcs (1.4.4)
     docile (1.4.0)
@@ -82,8 +86,13 @@ GEM
       railties (>= 5.0.0)
     faker (2.19.0)
       i18n (>= 1.6, < 2)
+    faraday (2.2.0)
+      faraday-net_http (~> 2.0)
+      ruby2_keywords (>= 0.0.4)
+    faraday-net_http (2.0.1)
     globalid (1.0.0)
       activesupport (>= 5.0)
+    hashdiff (1.0.1)
     i18n (1.8.11)
       concurrent-ruby (~> 1.0)
     importmap-rails (1.0.1)
@@ -120,6 +129,7 @@ GEM
     pry-byebug (3.9.0)
       byebug (~> 11.0)
       pry (~> 0.13.0)
+    public_suffix (4.0.6)
     puma (5.5.2)
       nio4r (~> 2.0)
     racc (1.6.0)
@@ -199,6 +209,7 @@ GEM
     rubocop-rspec (2.8.0)
       rubocop (~> 1.19)
     ruby-progressbar (1.11.0)
+    ruby2_keywords (0.0.5)
     shoulda-matchers (5.0.0)
       activesupport (>= 5.2.0)
     simplecov (0.21.2)
@@ -223,6 +234,10 @@ GEM
     tzinfo (2.0.4)
       concurrent-ruby (~> 1.0)
     unicode-display_width (2.1.0)
+    webmock (3.14.0)
+      addressable (>= 2.8.0)
+      crack (>= 0.3.2)
+      hashdiff (>= 0.4.0, < 2.0.0)
     websocket-driver (0.7.5)
       websocket-extensions (>= 0.1.0)
     websocket-extensions (0.1.5)
@@ -238,6 +253,7 @@ DEPENDENCIES
   dotenv-rails
   factory_bot_rails
   faker
+  faraday
   importmap-rails
   jbuilder
   pg (~> 1.1)
@@ -256,6 +272,7 @@ DEPENDENCIES
   sprockets-rails
   stimulus-rails
   turbo-rails
+  webmock
 
 RUBY VERSION
    ruby 3.0.3p157
diff --git a/app/concepts/project/operation/create_remix.rb b/app/concepts/project/operation/create_remix.rb
index 298ed8769..7a146e348 100644
--- a/app/concepts/project/operation/create_remix.rb
+++ b/app/concepts/project/operation/create_remix.rb
@@ -5,29 +5,29 @@ module Operation
     class CreateRemix
       require 'operation_response'
 
-      def self.call(params)
+      def self.call(params, user_id)
         response = OperationResponse.new
 
-        validate_params(response, params)
+        validate_params(response, params, user_id)
         return response if response.failure?
 
-        remix_project(response, params)
+        remix_project(response, params, user_id)
         response
       end
 
       class << self
         private
 
-        def validate_params(response, params)
-          valid = params[:phrase_id].present? && params[:remix][:user_id].present?
+        def validate_params(response, params, user_id)
+          valid = params[:phrase_id].present? && user_id.present?
           response[:error] = 'Invalid parameters' unless valid
         end
 
-        def remix_project(response, params)
+        def remix_project(response, params, user_id)
           original_project = Project.find_by!(identifier: params[:phrase_id])
 
           response[:project] = original_project.dup.tap do |proj|
-            proj.user_id = params[:remix][:user_id]
+            proj.user_id = user_id
             proj.components = original_project.components.map(&:dup)
           end
 
diff --git a/app/controllers/api/projects/remixes_controller.rb b/app/controllers/api/projects/remixes_controller.rb
index 38a0c530b..eb25f0a46 100644
--- a/app/controllers/api/projects/remixes_controller.rb
+++ b/app/controllers/api/projects/remixes_controller.rb
@@ -3,8 +3,10 @@
 module Api
   module Projects
     class RemixesController < ApiController
+      before_action :require_oauth_user
+
       def create
-        result = Project::Operation::CreateRemix.call(remix_params)
+        result = Project::Operation::CreateRemix.call(remix_params, oauth_user_id)
 
         if result.success?
           @project = result[:project]
@@ -17,7 +19,7 @@ def create
       private
 
       def remix_params
-        params.permit(:phrase_id, remix: [:user_id])
+        params.permit(:phrase_id)
       end
     end
   end
diff --git a/app/controllers/api_controller.rb b/app/controllers/api_controller.rb
index 878bfd879..1a43feefd 100644
--- a/app/controllers/api_controller.rb
+++ b/app/controllers/api_controller.rb
@@ -1,4 +1,19 @@
 # frozen_string_literal: true
 
 class ApiController < ActionController::API
+  include OauthUser
+
+  unless Rails.application.config.consider_all_requests_local
+    rescue_from ActiveRecord::RecordNotFound, with: -> { return404 }
+  end
+
+  private
+
+  def require_oauth_user
+    head :unauthorized unless oauth_user_id
+  end
+
+  def return404
+    render json: { error: '404 Not found' }, status: :not_found
+  end
 end
diff --git a/app/helpers/oauth_user.rb b/app/helpers/oauth_user.rb
new file mode 100644
index 000000000..22cd9ecd0
--- /dev/null
+++ b/app/helpers/oauth_user.rb
@@ -0,0 +1,27 @@
+# frozen_string_literal: true
+
+module OauthUser
+  def oauth_user_id
+    @oauth_user_id ||= fetch_oauth_user_id
+  end
+
+  private
+
+  def fetch_oauth_user_id
+    return nil if request.headers['Authorization'].blank?
+
+    json = hydra_request
+    json['sub']
+  end
+
+  def hydra_request
+    con = Faraday.new ENV.fetch('HYDRA_ADMIN_URL')
+    res = con.post do |req|
+      req.url '/oauth2/introspect'
+      req.headers['Content-Type'] = 'application/x-www-form-urlencoded'
+      req.headers['Authorization'] = "Basic #{ENV.fetch('HYDRA_SECRET')}"
+      req.body = { token: request.headers['Authorization'] }
+    end
+    JSON.parse(res.body)
+  end
+end
diff --git a/config/environments/test.rb b/config/environments/test.rb
index e67797f21..94716f034 100644
--- a/config/environments/test.rb
+++ b/config/environments/test.rb
@@ -25,7 +25,7 @@
   }
 
   # Show full error reports and disable caching.
-  config.consider_all_requests_local       = true
+  config.consider_all_requests_local       = false
   config.action_controller.perform_caching = false
   config.cache_store = :null_store
 
diff --git a/spec/concepts/project/operation/create_remix_spec.rb b/spec/concepts/project/operation/create_remix_spec.rb
index 780f97214..9cc6a6c69 100644
--- a/spec/concepts/project/operation/create_remix_spec.rb
+++ b/spec/concepts/project/operation/create_remix_spec.rb
@@ -3,7 +3,7 @@
 require 'rails_helper'
 
 RSpec.describe Project::Operation::CreateRemix, type: :unit do
-  subject(:create_remix) { described_class.call(params) }
+  subject(:create_remix) { described_class.call(params, user_id) }
 
   let(:user_id) { 'e0675b6c-dc48-4cd6-8c04-0f7ac05af51a' }
   let!(:original_project) { create(:project, :with_components) }
@@ -14,7 +14,7 @@
 
   describe '.call' do
     context 'when all params valid' do
-      let(:params) { { phrase_id: original_project.identifier, remix: { user_id: user_id } } }
+      let(:params) { { phrase_id: original_project.identifier } }
 
       it 'returns success' do
         result = create_remix
@@ -53,7 +53,8 @@
     end
 
     context 'when user_id is not present' do
-      let(:params) { { phrase_id: original_project.identifier, remix: { user_id: '' } } }
+      let(:user_id) { nil }
+      let(:params) { { phrase_id: original_project.identifier } }
 
       it 'returns failure' do
         result = create_remix
diff --git a/spec/rails_helper.rb b/spec/rails_helper.rb
index c2f7fa72e..5da0d50f2 100644
--- a/spec/rails_helper.rb
+++ b/spec/rails_helper.rb
@@ -1,6 +1,5 @@
 # frozen_string_literal: true
 
-# This file is copied to spec/ when you run 'rails generate rspec:install'
 require 'simplecov'
 SimpleCov.start 'rails' do
   enable_coverage :branch
@@ -9,10 +8,13 @@
 require 'spec_helper'
 ENV['RAILS_ENV'] ||= 'test'
 require File.expand_path('../config/environment', __dir__)
+
 # Prevent database truncation if the environment is production
 abort('The Rails environment is running in production mode!') if Rails.env.production?
 require 'rspec/rails'
+
 # Add additional requires below this line. Rails is not loaded until this point!
+require 'webmock/rspec'
 
 Dir[Rails.root.join('spec/support/**/*.rb')].each { |f| require f }
 
@@ -71,6 +73,7 @@
   # arbitrary gems may also be filtered via:
   # config.filter_gems_from_backtrace("gem name")
   config.include PhraseIdentifierMock
+  config.include OauthUserMock
 end
 
 Shoulda::Matchers.configure do |config|
diff --git a/spec/request/projects/remix_spec.rb b/spec/request/projects/remix_spec.rb
index 2b7805e19..1f1a62c46 100644
--- a/spec/request/projects/remix_spec.rb
+++ b/spec/request/projects/remix_spec.rb
@@ -11,19 +11,29 @@
       mock_phrase_generation
     end
 
-    it 'returns expected response' do
-      post "/api/projects/phrases/#{original_project.identifier}/remix",
-           params: { remix: { user_id: user_id } }
+    context 'when auth is correct' do
+      before do
+        mock_oauth_user
+      end
+
+      it 'returns success response' do
+        post "/api/projects/phrases/#{original_project.identifier}/remix"
+
+        expect(response.status).to eq(200)
+      end
+
+      it 'returns 404 response if invalid project' do
+        post '/api/projects/phrases/no-such-project/remix'
 
-      expect(response.status).to eq(200)
+        expect(response.status).to eq(404)
+      end
     end
 
-    context 'when request is invalid' do
-      it 'returns error response' do
-        post "/api/projects/phrases/#{original_project.identifier}/remix",
-             params: { remix: { user_id: '' } }
+    context 'when auth is invalid' do
+      it 'returns unauthorized' do
+        post "/api/projects/phrases/#{original_project.identifier}/remix"
 
-        expect(response.status).to eq(400)
+        expect(response.status).to eq(401)
       end
     end
   end
diff --git a/spec/support/oauth_user_mock.rb b/spec/support/oauth_user_mock.rb
new file mode 100644
index 000000000..59234bc94
--- /dev/null
+++ b/spec/support/oauth_user_mock.rb
@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+module OauthUserMock
+  def mock_oauth_user(user_id = nil)
+    user_id ||= SecureRandom.uuid
+
+    # rubocop:disable RSpec/AnyInstance
+    allow_any_instance_of(OauthUser).to receive(:oauth_user_id).and_return(user_id)
+    # rubocop:enable RSpec/AnyInstance
+  end
+end