Remove Flipper and replace with ENV-driven FeatureFlags (#957)

* Presence of valid DEFAULT_UI_LAYOUT is sufficient

* Linter

Gemfile

@@ -95,10 +95,6 @@ gem "omniauth-saml", "~> 2.1"
 gem "aasm"
 gem "after_commit_everywhere", "~> 1.0"
 
-# Feature flags
-gem "flipper"
-gem "flipper-active_record"
-
 # AI
 gem "ruby-openai"
 gem "langfuse-ruby", "~> 0.1.4", require: "langfuse"

Gemfile.lock

@@ -219,11 +219,6 @@ GEM
     ffi (1.17.2-x86_64-darwin)
     ffi (1.17.2-x86_64-linux-gnu)
     ffi (1.17.2-x86_64-linux-musl)
-    flipper (1.3.6)
-      concurrent-ruby (< 2)
-    flipper-active_record (1.3.6)
-      activerecord (>= 4.2, < 9)
-      flipper (~> 1.3.6)
     foreman (0.88.1)
     fugit (1.11.1)
       et-orbi (~> 1, >= 1.2.11)
@@ -803,8 +798,6 @@ DEPENDENCIES
   faraday
   faraday-multipart
   faraday-retry
-  flipper
-  flipper-active_record
   foreman
   hotwire-livereload
   hotwire_combobox

app/services/provider_loader.rb

@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 # Service class to load SSO provider configurations from either YAML or database
-# based on the :db_sso_providers feature flag.
+# based on the AUTH_PROVIDERS_SOURCE environment setting.
 #
 # Usage:
 #   providers = ProviderLoader.load_providers
@@ -38,17 +38,7 @@ class ProviderLoader
       def use_database_providers?
         return false if Rails.env.test?
 
-        begin
+        FeatureFlags.db_sso_providers?
-          # Check if feature exists, create if not (defaults to disabled)
-          unless Flipper.exist?(:db_sso_providers)
-            Flipper.add(:db_sso_providers)
-          end
-          Flipper.enabled?(:db_sso_providers)
-        rescue ActiveRecord::NoDatabaseError, ActiveRecord::StatementInvalid, StandardError => e
-          # Database not ready or other error, fall back to YAML
-          Rails.logger.warn("[ProviderLoader] Could not check feature flag (#{e.class}), falling back to YAML providers")
-          false
-        end
       end
 
       def load_from_database

app/views/admin/sso_providers/index.html.erb

@@ -3,7 +3,7 @@
 <div class="space-y-4">
   <p class="text-secondary mb-4">
     Manage single sign-on authentication providers for your instance.
-    <% unless Flipper.enabled?(:db_sso_providers) %>
+    <% unless FeatureFlags.db_sso_providers? %>
       <span class="text-warning">Changes require a server restart to take effect.</span>
     <% end %>
   </p>
@@ -107,7 +107,7 @@
           <p class="font-medium text-primary">Database-backed providers</p>
           <p class="text-sm text-secondary">Load providers from database instead of YAML config</p>
         </div>
-        <% if Flipper.enabled?(:db_sso_providers) %>
+        <% if FeatureFlags.db_sso_providers? %>
           <span class="inline-flex items-center px-2 py-0.5 rounded text-xs font-medium bg-green-100 text-green-800">
             Enabled
           </span>

app/views/invitations/new.html.erb

@@ -10,7 +10,7 @@
 
       <%= form.select :role,
         options_for_select([
-          (Flipper.enabled?(:intro_ui) ? [t(".role_guest"), "guest"] : nil),
+          (FeatureFlags.intro_ui? ? [t(".role_guest"), "guest"] : nil),
           [t(".role_member"), "member"],
           [t(".role_admin"), "admin"]
         ].compact),

config/initializers/flipper.rb

@@ -1,53 +0,0 @@
-# frozen_string_literal: true
-
-require "flipper"
-require "flipper/adapters/active_record"
-require "flipper/adapters/memory"
-
-# Configure Flipper with ActiveRecord adapter for database-backed feature flags
-# Falls back to memory adapter if tables don't exist yet (during migrations)
-Flipper.configure do |config|
-  config.adapter do
-    begin
-      Flipper::Adapters::ActiveRecord.new
-    rescue ActiveRecord::NoDatabaseError, ActiveRecord::StatementInvalid, NameError
-      # Tables don't exist yet, use memory adapter as fallback
-      Flipper::Adapters::Memory.new
-    end
-  end
-end
-
-# Initialize feature flags IMMEDIATELY (not in after_initialize)
-# This must happen before OmniAuth initializer runs
-unless Rails.env.test?
-  begin
-    # Feature flag to control SSO provider source (YAML vs DB)
-    # ENV: AUTH_PROVIDERS_SOURCE=db|yaml
-    # Default: "db" for self-hosted, "yaml" for managed
-    auth_source = ENV.fetch("AUTH_PROVIDERS_SOURCE") do
-      Rails.configuration.app_mode.self_hosted? ? "db" : "yaml"
-    end.downcase
-    default_ui_layout = ENV.fetch("DEFAULT_UI_LAYOUT", "").downcase
-
-    # Ensure feature exists before enabling/disabling
-    Flipper.add(:db_sso_providers) unless Flipper.exist?(:db_sso_providers)
-    if default_ui_layout.in?(%w[intro])
-      Flipper.add(:intro_ui, tags: [ :intro_ui ]) unless Flipper.exist?(:intro_ui)
-    end
-
-    if auth_source == "db"
-      Flipper.enable(:db_sso_providers)
-    else
-      Flipper.disable(:db_sso_providers)
-    end
-
-    if default_ui_layout.in?(%w[intro])
-      default_ui_layout == "intro" ? Flipper.enable(:intro_ui) : Flipper.disable(:intro_ui)
-    end
-  rescue ActiveRecord::NoDatabaseError, ActiveRecord::StatementInvalid
-    # Database not ready yet (e.g., during initial setup or migrations)
-    # This is expected during db:create or initial setup
-  rescue StandardError => e
-    Rails.logger.warn("[Flipper] Error initializing feature flags: #{e.message}")
-  end
-end

db/migrate/20260210120000_remove_flipper_tables.rb

@@ -0,0 +1,22 @@
+class RemoveFlipperTables < ActiveRecord::Migration[7.2]
+  def up
+    drop_table :flipper_gates, if_exists: true
+    drop_table :flipper_features, if_exists: true
+  end
+
+  def down
+    create_table :flipper_features do |t|
+      t.string :key, null: false
+      t.timestamps null: false
+    end
+    add_index :flipper_features, :key, unique: true
+
+    create_table :flipper_gates do |t|
+      t.string :feature_key, null: false
+      t.string :key, null: false
+      t.text :value
+      t.timestamps null: false
+    end
+    add_index :flipper_gates, [ :feature_key, :key, :value ], unique: true, length: { value: 255 }
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[7.2].define(version: 2026_02_08_110000) do
+ActiveRecord::Schema[7.2].define(version: 2026_02_10_120000) do
   # These are extensions that must be enabled in order to support this database
   enable_extension "pgcrypto"
   enable_extension "plpgsql"
@@ -522,22 +522,6 @@ ActiveRecord::Schema[7.2].define(version: 2026_02_08_110000) do
     t.index ["merchant_id"], name: "index_family_merchant_associations_on_merchant_id"
   end
 
-  create_table "flipper_features", force: :cascade do |t|
-    t.string "key", null: false
-    t.datetime "created_at", null: false
-    t.datetime "updated_at", null: false
-    t.index ["key"], name: "index_flipper_features_on_key", unique: true
-  end
-
-  create_table "flipper_gates", force: :cascade do |t|
-    t.string "feature_key", null: false
-    t.string "key", null: false
-    t.text "value"
-    t.datetime "created_at", null: false
-    t.datetime "updated_at", null: false
-    t.index ["feature_key", "key", "value"], name: "index_flipper_gates_on_feature_key_and_key_and_value", unique: true
-  end
-
   create_table "holdings", id: :uuid, default: -> { "gen_random_uuid()" }, force: :cascade do |t|
     t.uuid "account_id", null: false
     t.uuid "security_id", null: false

lib/feature_flags.rb

@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+
+module FeatureFlags
+  class << self
+    def db_sso_providers?
+      auth_source = ENV.fetch("AUTH_PROVIDERS_SOURCE") do
+        Rails.configuration.app_mode.self_hosted? ? "db" : "yaml"
+      end
+
+      auth_source.to_s.downcase == "db"
+    end
+
+    def intro_ui?
+      Rails.configuration.x.ui.default_layout.to_s.in?(%w[intro dashboard])
+    end
+  end
+end

test/controllers/invitations_controller_test.rb

@@ -9,7 +9,6 @@ class InvitationsControllerTest < ActionDispatch::IntegrationTest
   test "should get new" do
     get new_invitation_url
     assert_response :success
-    assert_select "option[value=?]", "guest", count: 0 unless Flipper.enabled?(:intro_ui)
     assert_select "option[value=?]", "member"
     assert_select "option[value=?]", "admin"
   end