diff --git a/app/controllers/achievements_controller.rb b/app/controllers/achievements_controller.rb
index f5ba036..919e562 100644
--- a/app/controllers/achievements_controller.rb
+++ b/app/controllers/achievements_controller.rb
@@ -2,11 +2,12 @@ class AchievementsController < ApplicationController
   before_action :authenticate_user!, except: [:index, :show]
 
   def index
-    @achievements = Achievement.order(date: :desc)
+    # Scope achievements to the current user
+    @achievements = current_user.achievements.order(date: :desc)
   end
 
   def show
-    @achievement = Achievement.find(params[:id])
+    @achievement = current_user.achievements.find(params[:id])
     AchievementView.create(
       achievement: @achievement,
       user: @achievement.user,
@@ -61,4 +62,4 @@ def destroy
   def achievement_params
     params.require(:achievement).permit(:title, :date, :description, :icon, :url)
   end
-end
\ No newline at end of file
+end
diff --git a/app/controllers/links_controller.rb b/app/controllers/links_controller.rb
index 3cb26ae..4b2baf7 100644
--- a/app/controllers/links_controller.rb
+++ b/app/controllers/links_controller.rb
@@ -1,13 +1,14 @@
 class LinksController < ApplicationController
   before_action :authenticate_user!, except: [:index, :show, :user_links, :track_click]
-  before_action :set_theme, only: [:user_links]  # Add this line
+  before_action :set_theme, only: [:user_links]
 
   def index
-    @links = Link.order(:position)
+    # Scope links to the current user
+    @links = current_user.links.order(:position)
   end
 
   def show
-    @link = Link.find(params[:id])
+    @link = current_user.links.find(params[:id])
   end
 
   def new
@@ -45,17 +46,17 @@ def destroy
   def user_links
     @user = User.find_by(username: params[:username])
     return redirect_to root_path, alert: "User not found" if @user.nil?
-  
-    @links = @user.links.where(hidden: false, visible: true)
-    @hidden_links = @user.links.where(hidden: true)
-    @pinned_links = @user.links.where(pinned: true)
+
+    @links = @user.links.visible
+    @hidden_links = @user.links.hidden
+    @pinned_links = @user.links.pinned
     @achievements = @user.achievements
     @user.tags = JSON.parse(@user.tags) if @user.tags.is_a?(String)
-  
+
     # Add debugging
     Rails.logger.debug "Theme: #{@theme.inspect}"
     Rails.logger.debug "Hidden Links: #{@hidden_links.inspect}"
-  
+
     # Render the appropriate template based on the theme
     case @theme
     when 'retro'
@@ -90,7 +91,6 @@ def link_params
   end
 
   def set_theme
-    # Determine the theme either from a query parameter or route segment
     @theme = params[:theme] || 'default'
   end
-end
\ No newline at end of file
+end
diff --git a/app/controllers/users/registrations_controller.rb b/app/controllers/users/registrations_controller.rb
index 0ffead2..5221a2e 100644
--- a/app/controllers/users/registrations_controller.rb
+++ b/app/controllers/users/registrations_controller.rb
@@ -1,10 +1,10 @@
 class Users::RegistrationsController < Devise::RegistrationsController
   before_action :configure_permitted_parameters, if: :devise_controller?
-  before_action :check_signups_enabled, only: [:new, :create]
+  before_action :check_signups_enabled, only: [:create]
 
   def create
-    # Check if sign-ups are disabled
-    if !Rails.application.config.sign_ups_open
+    # Check if sign-ups are disabled and no valid invite code is provided
+    unless Rails.application.config.sign_ups_open || valid_invite_code?(params[:user][:invite_code])
       redirect_to root_path, alert: "Sign-ups are currently disabled."
       return
     end
@@ -60,15 +60,32 @@ def update
     end
   end
 
+  private
+
+  def check_signups_enabled
+    # Check if sign-ups are disabled and no valid invite code is provided
+    if !Rails.application.config.sign_ups_open && (params[:user].blank? || !valid_invite_code?(params[:user][:invite_code]))
+      redirect_to root_path, alert: "Sign-ups are currently disabled."
+    end
+  end
+
+  def valid_invite_code?(invite_code)
+    # List of valid invite codes
+    valid_codes = ["POWEROVERWHELMING", "SWORDFISH", "HUNTER2"]
+  
+    # Check if the provided invite code matches any of the valid codes, case-insensitive
+    valid_codes.any? { |code| code.casecmp(invite_code).zero? }
+  end  
+
   protected
 
   def configure_permitted_parameters
-    devise_parameter_sanitizer.permit(:sign_up, keys: [:email, :password, :password_confirmation, :username, :full_name, :tags, :avatar, :banner, :description, :banner_enabled, :avatar_border])
+    devise_parameter_sanitizer.permit(:sign_up, keys: [:email, :password, :password_confirmation, :username, :full_name, :tags, :avatar, :banner, :description, :banner_enabled, :avatar_border, :invite_code])
     devise_parameter_sanitizer.permit(:account_update, keys: [:email, :password, :password_confirmation, :username, :full_name, :tags, :avatar, :banner, :description, :banner_enabled, :avatar_border])
   end
 
   def sign_up_params
-    params.require(:user).permit(:email, :password, :password_confirmation, :username, :full_name, :tags, :avatar, :banner, :description, :banner_enabled, :avatar_border).tap do |user_params|
+    params.require(:user).permit(:email, :password, :password_confirmation, :username, :full_name, :tags, :avatar, :banner, :description, :banner_enabled, :avatar_border, :invite_code).tap do |user_params|
       user_params[:tags] = user_params[:tags].split(',').map(&:strip).to_json if user_params[:tags].present?
     end
   end
@@ -78,12 +95,4 @@ def account_update_params
       user_params[:tags] = user_params[:tags].split(',').map(&:strip).to_json if user_params[:tags].present?
     end
   end
-
-  private
-
-  def check_signups_enabled
-    unless Rails.application.config.sign_ups_open
-      redirect_to root_path, alert: "Sign-ups are currently disabled."
-    end
-  end
 end
diff --git a/app/models/user.rb b/app/models/user.rb
index 74b70ce..a98a9ee 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -1,5 +1,6 @@
 # app/models/user.rb
 class User < ApplicationRecord
+  attr_accessor :invite_code
   devise :database_authenticatable, :registerable,
          :recoverable, :rememberable, :validatable
 
diff --git a/app/services/open_graph_image_generator.rb b/app/services/open_graph_image_generator.rb
index 2f65da5..29aae56 100644
--- a/app/services/open_graph_image_generator.rb
+++ b/app/services/open_graph_image_generator.rb
@@ -54,10 +54,17 @@ def generate
   def download_image(url)
     tempfile = Tempfile.new(['avatar', '.jpg'])
     tempfile.binmode
-    URI.open(url) do |image|
-      tempfile.write(image.read)
+    begin
+      URI.open(url) do |image|
+        tempfile.write(image.read)
+      end
+    rescue OpenURI::HTTPError, Errno::ENOENT, SocketError => e
+      Rails.logger.error("Failed to download image from URL: #{url}. Error: #{e.message}. Using default image.")
+      # Use a default image if the download fails
+      default_image_path = Rails.root.join('app', 'assets', 'images', 'greg.jpg')
+      tempfile.write(File.read(default_image_path))
     end
     tempfile.rewind
     MiniMagick::Image.open(tempfile.path)
   end
-end
\ No newline at end of file
+end
diff --git a/app/views/devise/registrations/new.html.erb b/app/views/devise/registrations/new.html.erb
index cc71baa..a477fdc 100644
--- a/app/views/devise/registrations/new.html.erb
+++ b/app/views/devise/registrations/new.html.erb
@@ -1,69 +1,80 @@
 <div class="max-w-2xl mx-auto p-6 bg-gray-800 rounded-lg shadow-md">
   <h2 class="text-2xl font-bold mb-6 text-lime-200">Sign up</h2>
 
-  <% if Rails.application.config.sign_ups_open %>
-    <%= form_for(resource, as: resource_name, url: registration_path(resource_name), html: { class: "space-y-6" }) do |f| %>
-      <%= render "devise/shared/error_messages", resource: resource %>
+  <%= form_for(resource, as: resource_name, url: registration_path(resource_name), html: { class: "space-y-6" }) do |f| %>
+    <%= render "devise/shared/error_messages", resource: resource %>
 
-      <div>
-        <%= f.label :email, class: 'block text-lime-200 font-semibold mb-2' %>
-        <%= f.email_field :email, autofocus: true, autocomplete: "email", class: 'block w-full px-4 py-2 border border-gray-700 rounded bg-gray-900 text-white focus:outline-none focus:border-lime-500' %>
-      </div>
+    <div>
+      <%= f.label :email, class: 'block text-lime-200 font-semibold mb-2' %>
+      <%= f.email_field :email, autofocus: true, autocomplete: "email", class: 'block w-full px-4 py-2 border border-gray-700 rounded bg-gray-900 text-white focus:outline-none focus:border-lime-500' %>
+    </div>
+
+    <div>
+      <%= f.label :password, class: 'block text-lime-200 font-semibold mb-2' %>
+      <% if @minimum_password_length %>
+        <em class="text-gray-400 text-sm">(<%= @minimum_password_length %> characters minimum)</em>
+      <% end %>
+      <%= f.password_field :password, autocomplete: "new-password", class: 'block w-full px-4 py-2 border border-gray-700 rounded bg-gray-900 text-white focus:outline-none focus:border-lime-500' %>
+    </div>
 
-      <div>
-        <%= f.label :password, class: 'block text-lime-200 font-semibold mb-2' %>
-        <% if @minimum_password_length %>
-          <em class="text-gray-400 text-sm">(<%= @minimum_password_length %> characters minimum)</em>
-        <% end %>
-        <%= f.password_field :password, autocomplete: "new-password", class: 'block w-full px-4 py-2 border border-gray-700 rounded bg-gray-900 text-white focus:outline-none focus:border-lime-500' %>
-      </div>
+    <div>
+      <%= f.label :password_confirmation, class: 'block text-lime-200 font-semibold mb-2' %>
+      <%= f.password_field :password_confirmation, autocomplete: "new-password", class: 'block w-full px-4 py-2 border border-gray-700 rounded bg-gray-900 text-white focus:outline-none focus:border-lime-500' %>
+    </div>
 
-      <div>
-        <%= f.label :password_confirmation, class: 'block text-lime-200 font-semibold mb-2' %>
-        <%= f.password_field :password_confirmation, autocomplete: "new-password", class: 'block w-full px-4 py-2 border border-gray-700 rounded bg-gray-900 text-white focus:outline-none focus:border-lime-500' %>
-      </div>
+    <div>
+      <%= f.label :username, class: 'block text-lime-200 font-semibold mb-2' %>
+      <%= f.text_field :username, class: 'block w-full px-4 py-2 border border-gray-700 rounded bg-gray-900 text-white focus:outline-none focus:border-lime-500' %>
+    </div>
+
+    <div>
+      <%= f.label :full_name, class: 'block text-lime-200 font-semibold mb-2' %>
+      <%= f.text_field :full_name, class: 'block w-full px-4 py-2 border border-gray-700 rounded bg-gray-900 text-white focus:outline-none focus:border-lime-500' %>
+    </div>
 
-      <div>
-        <%= f.label :username, class: 'block text-lime-200 font-semibold mb-2' %>
-        <%= f.text_field :username, class: 'block w-full px-4 py-2 border border-gray-700 rounded bg-gray-900 text-white focus:outline-none focus:border-lime-500' %>
-      </div>
+    <div>
+      <%= f.label :tags, class: 'block text-lime-200 font-semibold mb-2' %>
+      <%= f.text_field :tags, value: @user.parsed_tags.join(', '), class: 'block w-full px-4 py-2 border border-gray-700 rounded bg-gray-900 text-white focus:outline-none focus:border-lime-500' %>
+    </div>
 
-      <div>
-        <%= f.label :full_name, class: 'block text-lime-200 font-semibold mb-2' %>
-        <%= f.text_field :full_name, class: 'block w-full px-4 py-2 border border-gray-700 rounded bg-gray-900 text-white focus:outline-none focus:border-lime-500' %>
-      </div>
+    <div>
+      <%= f.label :avatar, class: 'block text-lime-200 font-semibold mb-2' %>
+      <%= f.text_field :avatar, class: 'block w-full px-4 py-2 border border-gray-700 rounded bg-gray-900 text-white focus:outline-none focus:border-lime-500' %>
+    </div>
 
-      <div>
-        <%= f.label :tags, class: 'block text-lime-200 font-semibold mb-2' %>
-        <%= f.text_field :tags, value: @user.parsed_tags.join(', '), class: 'block w-full px-4 py-2 border border-gray-700 rounded bg-gray-900 text-white focus:outline-none focus:border-lime-500' %>
-      </div>
+    <div>
+      <%= f.label :avatar_border, class: 'block text-lime-200 font-semibold mb-2' %>
+      <%= f.select :avatar_border, options_for_select([
+        ['White', 'white'],
+        ['Black', 'black'],
+        ['None', 'none'],
+        ['Rainbow', 'rainbow'],
+        ['Rainbow Overlay', 'rainbow-overlay']
+      ], @user.avatar_border), {}, class: 'block w-full px-4 py-2 border border-gray-700 rounded bg-gray-900 text-white focus:outline-none focus:border-lime-500' %>
+    </div>
 
-      <div>
-        <%= f.label :avatar, class: 'block text-lime-200 font-semibold mb-2' %>
-        <%= f.text_field :avatar, class: 'block w-full px-4 py-2 border border-gray-700 rounded bg-gray-900 text-white focus:outline-none focus:border-lime-500' %>
-      </div>
+    <div>
+      <%= f.label :banner, class: 'block text-lime-200 font-semibold mb-2' %>
+      <%= f.text_field :banner, class: 'block w-full px-4 py-2 border border-gray-700 rounded bg-gray-900 text-white focus:outline-none focus:border-lime-500' %>
+    </div>
 
-      <div>
-        <%= f.label :banner, class: 'block text-lime-200 font-semibold mb-2' %>
-        <%= f.text_field :banner, class: 'block w-full px-4 py-2 border border-gray-700 rounded bg-gray-900 text-white focus:outline-none focus:border-lime-500' %>
-      </div>
+    <div>
+      <%= f.label :description, class: 'block text-lime-200 font-semibold mb-2' %>
+      <%= f.text_area :description, rows: 3, class: 'block w-full px-4 py-2 border border-gray-700 rounded bg-gray-900 text-white focus:outline-none focus:border-lime-500' %>
+    </div>
 
-      <div>
-        <%= f.label :description, class: 'block text-lime-200 font-semibold mb-2' %>
-        <%= f.text_area :description, rows: 3, class: 'block w-full px-4 py-2 border border-gray-700 rounded bg-gray-900 text-white focus:outline-none focus:border-lime-500' %>
-      </div>
+    <!-- Invite code field -->
+    <div>
+      <%= f.label :invite_code, "Invite Code", class: 'block text-lime-200 font-semibold mb-2' %>
+      <%= f.text_field :invite_code, class: 'block w-full px-4 py-2 border border-gray-700 rounded bg-gray-900 text-white focus:outline-none focus:border-lime-500' %>
+    </div>
 
-      <div class="actions text-center">
-        <%= f.submit "Sign up", class: 'bg-lime-500 hover:bg-lime-600 text-white font-bold py-2 px-4 rounded transition duration-300 ease-in-out focus:outline-none' %>
-      </div>
-    <% end %>
-  <% else %>
-    <div class="text-center text-red-500">
-      <p>Sign-ups are currently disabled.</p>
+    <div class="actions text-center">
+      <%= f.submit "Sign up", class: 'bg-lime-500 hover:bg-lime-600 text-white font-bold py-2 px-4 rounded transition duration-300 ease-in-out focus:outline-none' %>
     </div>
   <% end %>
+</div>
 
-  <div class="mt-4 text-center">
-    <%= render "devise/shared/links" %>
-  </div>
+<div class="mt-4 text-center">
+  <%= render "devise/shared/links" %>
 </div>
diff --git a/app/views/devise/shared/_links.html.erb b/app/views/devise/shared/_links.html.erb
index 8cef40a..a435cde 100644
--- a/app/views/devise/shared/_links.html.erb
+++ b/app/views/devise/shared/_links.html.erb
@@ -2,10 +2,8 @@
   <%= link_to "Log in", new_session_path(resource_name), class: "text-lime-300 hover:text-lime-100 transition duration-300 ease-in-out" %><br />
 <% end %>
 
-<% if Rails.application.config.sign_ups_open %>
-  <%- if devise_mapping.registerable? && controller_name != 'registrations' %>
-    <%= link_to "Sign up", new_registration_path(resource_name), class: "text-lime-300 hover:text-lime-100 transition duration-300 ease-in-out" %><br />
-  <% end %>
+<% if devise_mapping.registerable? && controller_name != 'registrations' %>
+  <%= link_to "Sign up", new_registration_path(resource_name), class: "text-lime-300 hover:text-lime-100 transition duration-300 ease-in-out" %><br />
 <% end %>
 
 <%- if devise_mapping.recoverable? && controller_name != 'passwords' && controller_name != 'registrations' %>
@@ -24,4 +22,4 @@
   <%- resource_class.omniauth_providers.each do |provider| %>
     <%= button_to "Sign in with #{OmniAuth::Utils.camelize(provider)}", omniauth_authorize_path(resource_name, provider), data: { turbo: false }, class: "mt-2 bg-gray-600 hover:bg-gray-700 text-white font-bold py-2 px-4 rounded transition duration-300 ease-in-out focus:outline-none focus:ring-2 focus:ring-gray-500 focus:ring-opacity-50" %><br />
   <% end %>
-<% end %>
\ No newline at end of file
+<% end %>
diff --git a/config/routes.rb b/config/routes.rb
index f5ccce9..cb4eb19 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -1,4 +1,6 @@
 Rails.application.routes.draw do
+  # Static and more specific routes first
+
   get 'analytics/index'
 
   # Devise routes for user registration
@@ -19,10 +21,10 @@
   # Root route
   root to: 'pages#home'
 
-  # Static routes should be defined before dynamic routes
+  # Routes for achievements
   resources :achievements, only: [:index, :show, :new, :create, :edit, :update, :destroy]
 
-  # Routes for links with standard RESTful actions - move these above the dynamic route
+  # Routes for links with standard RESTful actions
   resources :links do
     member do
       get :track_click
diff --git a/spec/controllers/achievements_controller_spec.rb b/spec/controllers/achievements_controller_spec.rb
index d4fa78f..df439e2 100644
--- a/spec/controllers/achievements_controller_spec.rb
+++ b/spec/controllers/achievements_controller_spec.rb
@@ -5,6 +5,10 @@
   let(:user) { create(:user) }
   let(:achievement) { create(:achievement, user: user) }
 
+  before do
+    sign_in user  # Sign in the user before each test
+  end
+
   describe "GET #index" do
     it "returns a success response" do
       get :index
@@ -38,7 +42,6 @@
 
   describe "GET #new" do
     it "returns a success response" do
-      sign_in user
       get :new
       expect(response).to be_successful
     end
@@ -47,7 +50,6 @@
   describe "POST #create" do
     context "with valid params" do
       it "creates a new Achievement" do
-        sign_in user
         expect {
           post :create, params: { achievement: attributes_for(:achievement) }
         }.to change(Achievement, :count).by(1)
@@ -60,7 +62,6 @@
       let(:new_attributes) { { title: "New Title" } }
 
       it "updates the requested achievement" do
-        sign_in user
         put :update, params: { id: achievement.to_param, achievement: new_attributes }
         achievement.reload
         expect(achievement.title).to eq("New Title")
@@ -70,11 +71,10 @@
 
   describe "DELETE #destroy" do
     it "destroys the requested achievement" do
-      sign_in user
       achievement # ensure achievement is created before the expect block
       expect {
         delete :destroy, params: { id: achievement.to_param }
       }.to change(Achievement, :count).by(-1)
     end
   end
-end
\ No newline at end of file
+end
diff --git a/spec/controllers/links_controller_spec.rb b/spec/controllers/links_controller_spec.rb
index ea77088..aaeaef1 100644
--- a/spec/controllers/links_controller_spec.rb
+++ b/spec/controllers/links_controller_spec.rb
@@ -5,6 +5,10 @@
   let(:user) { create(:user) }
   let(:link) { create(:link, user: user) }
 
+  before do
+    sign_in user  # Sign in the user before each test
+  end
+
   describe "GET #index" do
     it "returns a success response" do
       get :index
@@ -21,7 +25,6 @@
 
   describe "GET #new" do
     it "returns a success response" do
-      sign_in user
       get :new
       expect(response).to be_successful
     end
@@ -30,7 +33,6 @@
   describe "POST #create" do
     context "with valid params" do
       it "creates a new Link" do
-        sign_in user
         expect {
           post :create, params: { link: attributes_for(:link) }
         }.to change(Link, :count).by(1)
@@ -43,7 +45,6 @@
       let(:new_attributes) { { title: "New Title" } }
 
       it "updates the requested link" do
-        sign_in user
         put :update, params: { id: link.to_param, link: new_attributes }
         link.reload
         expect(link.title).to eq("New Title")
@@ -53,7 +54,6 @@
 
   describe "DELETE #destroy" do
     it "destroys the requested link" do
-      sign_in user
       link # ensure link is created before the expect block
       expect {
         delete :destroy, params: { id: link.to_param }
diff --git a/spec/controllers/users/registrations_controller_spec.rb b/spec/controllers/users/registrations_controller_spec.rb
index 371caa5..d58e0ce 100644
--- a/spec/controllers/users/registrations_controller_spec.rb
+++ b/spec/controllers/users/registrations_controller_spec.rb
@@ -8,7 +8,7 @@
   describe "POST #create" do
     let(:valid_attributes) {
       { email: "test@example.com", password: "password", password_confirmation: "password",
-        username: "testuser", full_name: "Test User", tags: "tag1,tag2", avatar_border: "white" }
+        username: "testuser", full_name: "Test User", tags: "tag1,tag2", avatar_border: "white", invite_code: "POWEROVERWHELMING" }
     }
 
     context "when sign-ups are enabled" do
@@ -35,13 +35,24 @@
         allow(Rails.application.config).to receive(:sign_ups_open).and_return(false)
       end
 
-      it "does not create a new User and redirects to root path" do
+      it "does not create a new User without a valid invite code and redirects to root path" do
+        invalid_attributes = valid_attributes.merge(invite_code: "INVALIDCODE")
         expect {
-          post :create, params: { user: valid_attributes }
+          post :create, params: { user: invalid_attributes }
         }.not_to change(User, :count)
         expect(response).to redirect_to(root_path)
         expect(flash[:alert]).to eq("Sign-ups are currently disabled.")
       end
+
+      it "creates a new User with a valid invite code" do
+        expect(controller).to receive(:after_sign_up_path_for).with(instance_of(User)).and_return("/path/to/redirect")
+
+        expect {
+          post :create, params: { user: valid_attributes }
+        }.to change(User, :count).by(1)
+        
+        expect(response).to redirect_to("/path/to/redirect")
+      end
     end
   end