From 6f7ee5e1d5c5927dac7057296e75a65cb3d9c32c Mon Sep 17 00:00:00 2001
From: Olli Pikarinen <pikariop@users.noreply.github.com>
Date: Fri, 17 Jul 2026 10:03:07 +0300
Subject: [PATCH 1/6] chore: sort ns form

---
 src/cljs/rems/administration/catalogue_item.cljs | 2 +-
 test/clj/rems/application/test_commands.clj      | 6 +++---
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/cljs/rems/administration/catalogue_item.cljs b/src/cljs/rems/administration/catalogue_item.cljs
index cba7afed0..55c21d23d 100644
--- a/src/cljs/rems/administration/catalogue_item.cljs
+++ b/src/cljs/rems/administration/catalogue_item.cljs
@@ -6,8 +6,8 @@
             [rems.administration.status-flags :as status-flags]
             [rems.atoms :as atoms :refer [document-title readonly-checkbox]]
             [rems.collapsible :as collapsible]
-            [rems.flash-message :as flash-message]
             [rems.common.roles :as roles]
+            [rems.flash-message :as flash-message]
             [rems.spinner :as spinner]
             [rems.text :refer [get-localized-title localize-time localized text]]
             [rems.util :refer [fetch]]))
diff --git a/test/clj/rems/application/test_commands.clj b/test/clj/rems/application/test_commands.clj
index ee1231a18..947ccc9f7 100644
--- a/test/clj/rems/application/test_commands.clj
+++ b/test/clj/rems/application/test_commands.clj
@@ -1,13 +1,13 @@
 (ns rems.application.test-commands
-  (:require [clojure.test :refer [deftest is testing]]
+  (:require [clj-time.core :as time]
+            [clojure.test :refer [deftest is testing]]
             [rems.application.commands :as commands]
             [rems.application.events :as events]
             [rems.application.model :as model]
             [rems.common.util :refer [getx]]
             [rems.permissions :as permissions]
-            [rems.util :refer [assert-ex]]
             [rems.testing-util :refer [with-fixed-time]]
-            [clj-time.core :as time])
+            [rems.util :refer [assert-ex]])
   (:import [clojure.lang ExceptionInfo]
            [java.util UUID]
            [org.joda.time DateTime]))

From c91c6d8bc3231ae1b15cce8be6aeccc57f8c8461 Mon Sep 17 00:00:00 2001
From: Olli Pikarinen <pikariop@users.noreply.github.com>
Date: Fri, 17 Jul 2026 10:05:25 +0300
Subject: [PATCH 2/6] chore: normalize alias

---
 src/cljs/rems/flash_message.cljs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/cljs/rems/flash_message.cljs b/src/cljs/rems/flash_message.cljs
index 6262140b3..d9de67112 100644
--- a/src/cljs/rems/flash_message.cljs
+++ b/src/cljs/rems/flash_message.cljs
@@ -1,5 +1,5 @@
 (ns rems.flash-message
-  (:require [clojure.string :as string]
+  (:require [clojure.string :as str]
             [clojure.test :refer [deftest is are]]
             [clojure.walk]
             [re-frame.core :as rf]
@@ -130,7 +130,7 @@
                  ((apply some-fn id-keys))
                  vector
                  flatten
-                 (string/join ", "))])))
+                 (str/join ", "))])))
 
 (deftest test-argumentize-some-key
   (are [expected input] (= expected ((argumentize-some-key :a :b) input))

From 9893cbb08f8e5fc6929b237d7a351c34077c6ba2 Mon Sep 17 00:00:00 2001
From: Olli Pikarinen <pikariop@users.noreply.github.com>
Date: Fri, 17 Jul 2026 15:12:39 +0300
Subject: [PATCH 3/6] Update manual

---
 manual/owner.md | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/manual/owner.md b/manual/owner.md
index 890261768..711092bcd 100644
--- a/manual/owner.md
+++ b/manual/owner.md
@@ -180,7 +180,9 @@ This will **disable and archive the old catalogue item** and create a new catalo
 
 Catalogue items can be grouped under **Categories** that display as folding sub-headers on the catalogue page, also referred to as the **catalogue tree**. Categories can have subcategories and they can be nested in a tree-like structure.
 
-Additionally, catalogue items may specify **complementary items** that must be applied for together with the **top-level catalogue item**. A top-level catalogue item may have many complementary items, and there can only be one top-level item for a given complementary item. A catalogue item that is already referenced by a top-level item may not have complementary items of it's own.
+Additionally, catalogue items may specify **complementary items** that must be applied for together with the **top-level catalogue item**. To use this feature, configure `:enable-catalogue-hierarchy` to `true`. 
+
+A top-level catalogue item may have many complementary items, and there can only be one top-level item for a given complementary item. A catalogue item that is already referenced by a top-level item may not have complementary items of it's own. Once the applicant has been given entitlement to the resource of a top-level item, it's complementary items become applicable on their own as ordinary catalogue items.
 
 ## Disabling, and archiving items
 

From 56faf61b8a79ed8b0ec8631d523490c7194e1248 Mon Sep 17 00:00:00 2001
From: Olli Pikarinen <pikariop@users.noreply.github.com>
Date: Fri, 17 Jul 2026 16:34:35 +0300
Subject: [PATCH 4/6] Update changelog

---
 CHANGELOG.md | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index f8b2ae669..82fb57cb8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,9 @@ have notable changes.
 
 Changes since v2.39.1
 
+### Additions
+- Added applicant UI for catalogue item hierarchy (see previous release note), and a configuration option to switch the feature on. (#3460, #3473). See (manual/owner.md)[manual/owner.md] and 
+
 ### Fixes
 - Fixed an issue where the application page would get stuck on a loop, displaying the "loading" indicator, when there was an error while creating the application (#3460).
 

From 519e729da0bd25789023b94fa1cf1a017f488f7d Mon Sep 17 00:00:00 2001
From: Olli Pikarinen <pikariop@users.noreply.github.com>
Date: Fri, 17 Jul 2026 16:18:27 +0300
Subject: [PATCH 5/6] Add feature flag for catalogue item hierarchy

---
 dev-config.edn                                |  1 +
 resources/config-defaults.edn                 |  4 +
 src/clj/rems/api/public.clj                   |  1 +
 src/clj/rems/application/commands.clj         | 27 ++++---
 src/clj/rems/service/public.clj               |  1 +
 .../rems/administration/catalogue_item.cljs   | 29 +++----
 .../administration/create_catalogue_item.cljs |  7 +-
 src/cljs/rems/cart.cljs                       | 79 ++++++++++---------
 test-config.edn                               |  1 +
 test/clj/rems/api/test_applications.clj       |  7 +-
 test/clj/rems/application/test_commands.clj   | 67 ++++++++++++----
 test/clj/rems/test_browser.clj                | 56 ++++++++++++-
 12 files changed, 192 insertions(+), 88 deletions(-)

diff --git a/dev-config.edn b/dev-config.edn
index 70dfa76e0..fea74d86f 100644
--- a/dev-config.edn
+++ b/dev-config.edn
@@ -89,6 +89,7 @@
  :enable-doi true
  :enable-duo true
  :enable-catalogue-tree true
+ :enable-catalogue-hierarchy true
  :enable-save-compaction true
  :enable-autosave true
  :enable-extended-logging true
diff --git a/resources/config-defaults.edn b/resources/config-defaults.edn
index 147c15181..67e8bf555 100644
--- a/resources/config-defaults.edn
+++ b/resources/config-defaults.edn
@@ -425,6 +425,10 @@
  :enable-save-compaction false ; whether to merge consecutive saves into one event (EXPERIMENTAL)
  :enable-autosave false ; whether to automatically save the application as the applicant types (EXPERIMENTAL)
 
+ ;; Enable
+ ;; See `manual/owner.md` and `docs/architecture/023-catalogue-item-hierarchy.md`
+ :enable-catalogue-hierarchy false
+
  ;; Extended logging for routes that should additionally log content of entity mutation.
  ;; logging is at INFO level and the log message is prefixed with "extended-logging (:uri request)"
  :enable-extended-logging false
diff --git a/src/clj/rems/api/public.clj b/src/clj/rems/api/public.clj
index 9fdc76932..90037c267 100644
--- a/src/clj/rems/api/public.clj
+++ b/src/clj/rems/api/public.clj
@@ -43,6 +43,7 @@
    (s/optional-key :enable-catalogue-tree) s/Bool
    (s/optional-key :catalogue-tree-show-matching-parents) s/Bool
    (s/optional-key :enable-cart) s/Bool
+   (s/optional-key :enable-catalogue-hierarchy) s/Bool
    (s/optional-key :application-list-hidden-columns) [s/Keyword]
    (s/optional-key :enable-autosave) s/Bool
    (s/optional-key :show-resources-section) s/Bool
diff --git a/src/clj/rems/application/commands.clj b/src/clj/rems/application/commands.clj
index 4f71e526d..fd0e81a92 100644
--- a/src/clj/rems/application/commands.clj
+++ b/src/clj/rems/application/commands.clj
@@ -105,19 +105,20 @@
 
 (defn- invalid-catalogue-item-hierarchy-error
   "For such an item in `catalogue-item-ids` that has a parent (dependent), check that the parent item is also included in `catalogue-item-ids`, or `actor` has an entitlement to the parent item's resource."
-  [catalogue-item-ids actor {:keys [get-catalogue-item get-dependents get-entitlements]}]
-  (let [entitled-to-resids (into #{} (map :resourceid) (get-entitlements actor))
-        missing (into []
-                      (comp (mapcat (fn [id] (get-dependents {:catalogue-item/id id})))
-                            (map :catalogue-item/id)
-                            (remove (set catalogue-item-ids))
-                            (map get-catalogue-item)
-                            (filter (complement (comp entitled-to-resids :resource-id)))
-                            (map :id))
-                      catalogue-item-ids)]
-    (when (seq missing)
-      {:errors [{:type :t.applications.errors/missing-top-level-item
-                 :catalogue-item-ids missing}]})))
+  [catalogue-item-ids actor {:keys [get-catalogue-item get-dependents get-entitlements get-config]}]
+  (when (:enable-catalogue-hierarchy (get-config))
+    (let [entitled-to-resids (into #{} (map :resourceid) (get-entitlements actor))
+          missing (into []
+                        (comp (mapcat (fn [id] (get-dependents {:catalogue-item/id id})))
+                              (map :catalogue-item/id)
+                              (remove (set catalogue-item-ids))
+                              (map get-catalogue-item)
+                              (filter (complement (comp entitled-to-resids :resource-id)))
+                              (map :id))
+                        catalogue-item-ids)]
+      (when (seq missing)
+        {:errors [{:type :t.applications.errors/missing-top-level-item
+                   :catalogue-item-ids missing}]}))))
 
 (defn- licenses-not-accepted-error [application userid]
   (when-not (application-util/accepted-licenses? application userid)
diff --git a/src/clj/rems/service/public.clj b/src/clj/rems/service/public.clj
index 22a5a79fc..e5ebc1fc0 100644
--- a/src/clj/rems/service/public.clj
+++ b/src/clj/rems/service/public.clj
@@ -36,6 +36,7 @@
                     :enable-catalogue-tree
                     :catalogue-tree-show-matching-parents
                     :enable-cart
+                    :enable-catalogue-hierarchy
                     :application-list-hidden-columns
                     :enable-autosave
                     :show-resources-section
diff --git a/src/cljs/rems/administration/catalogue_item.cljs b/src/cljs/rems/administration/catalogue_item.cljs
index 55c21d23d..939ff3632 100644
--- a/src/cljs/rems/administration/catalogue_item.cljs
+++ b/src/cljs/rems/administration/catalogue_item.cljs
@@ -8,6 +8,7 @@
             [rems.collapsible :as collapsible]
             [rems.common.roles :as roles]
             [rems.flash-message :as flash-message]
+            [rems.globals]
             [rems.spinner :as spinner]
             [rems.text :refer [get-localized-title localize-time localized text]]
             [rems.util :refer [fetch]]))
@@ -95,22 +96,22 @@
                            ^{:key (:category/id cat)}
                            [atoms/link nil
                             (str "/administration/categories/" (:category/id cat))
-                            (localized (:category/title cat))])))]
-                     [inline-info-field (text :t.administration/catalogue-item-hierarchy-parent)
-                      (let [{id :catalogue-item/id} (:part-of catalogue-item)]
-                        (when id
+                            (localized (:category/title cat))])))]]
+                    (when (:enable-catalogue-hierarchy @rems.globals/config)
+                      [[inline-info-field (text :t.administration/catalogue-item-hierarchy-parent)
+                        (when-let [id (:catalogue-item/id (:part-of catalogue-item))]
                           [atoms/link {:href (str "/administration/catalogue-items/" id)
                                        :label id
-                                       :target :_blank}]))]
-                     [inline-info-field (text :t.administration/catalogue-item-hierarchy-children)
-                      (when-let [children (:children catalogue-item)]
-                        (doall
-                         (for [{id :catalogue-item/id} children]
-                           ^{:key id}
-                           [atoms/link {:href (str "/administration/catalogue-items/" id)
-                                        :label id
-                                        :target :_blank}])))]
-                     [inline-info-field (text :t.administration/start) (localize-time (:start catalogue-item))]
+                                       :target :_blank}])]
+                       [inline-info-field (text :t.administration/catalogue-item-hierarchy-children)
+                        (when-let [children (:children catalogue-item)]
+                          (doall
+                           (for [{id :catalogue-item/id} children]
+                             ^{:key id}
+                             [atoms/link {:href (str "/administration/catalogue-items/" id)
+                                          :label id
+                                          :target :_blank}])))]])
+                    [[inline-info-field (text :t.administration/start) (localize-time (:start catalogue-item))]
                      [inline-info-field (text :t.administration/end) (localize-time (:end catalogue-item))]
                      [inline-info-field (text :t.administration/active) [readonly-checkbox {:value (status-flags/active? catalogue-item)}]]]))}]
    (let [id (:id catalogue-item)]
diff --git a/src/cljs/rems/administration/create_catalogue_item.cljs b/src/cljs/rems/administration/create_catalogue_item.cljs
index 738e29127..d332fba1d 100644
--- a/src/cljs/rems/administration/create_catalogue_item.cljs
+++ b/src/cljs/rems/administration/create_catalogue_item.cljs
@@ -396,9 +396,10 @@
                    [catalogue-item-resource-field]
                    [catalogue-item-form-field]
                    [catalogue-item-categories-field]
-                   (if parent-item
-                     [catalogue-item-parent-field parent-item]
-                     [catalogue-item-children-field])
+                   (when (:enable-catalogue-hierarchy @rems.globals/config)
+                     (if parent-item
+                       [catalogue-item-parent-field parent-item]
+                       [catalogue-item-children-field]))
 
                    [:div.col.commands
                     [cancel-button catalogue-item-id]
diff --git a/src/cljs/rems/cart.cljs b/src/cljs/rems/cart.cljs
index 412c7836f..7d3e5b92a 100644
--- a/src/cljs/rems/cart.cljs
+++ b/src/cljs/rems/cart.cljs
@@ -6,6 +6,7 @@
             [re-frame.core :as rf]
             [rems.atoms :as atoms]
             [rems.common.catalogue-util :refer [catalogue-items->ids]]
+            [rems.globals]
             [rems.guide-util :refer [component-info example]]
             [rems.text :refer [get-localized-title text text-format]]
             [rems.util :refer [navigate!]]))
@@ -28,49 +29,53 @@
    (update db ::cart #(remove (comp #{item-id} :id) %))))
 
 (defn disable-remove-from-cart-button? [item cart-item-ids entitlement-catids]
-  (when-let [children-ids (seq (map :catalogue-item/id (:children item)))]
-    (and (not (contains? (set entitlement-catids) (:id item)))
-         (some (set cart-item-ids) children-ids))))
+  (when (:enable-catalogue-hierarchy @rems.globals/config)
+    (when-let [children-ids (seq (map :catalogue-item/id (:children item)))]
+      (and (not (contains? (set entitlement-catids) (:id item)))
+           (some (set cart-item-ids) children-ids)))))
 
 (deftest test-disable-remove-from-cart-button
-  (testing "without hierarchy"
-    (is (nil? (disable-remove-from-cart-button? {:id 1} [1] nil))
-        "can remove item")
-    (is (nil? (disable-remove-from-cart-button? {:id 1} [1 2 3] nil))
-        "can remove item"))
-  (testing "with item and children in cart"
-    (is (disable-remove-from-cart-button? {:id 2 :children [{:catalogue-item/id 3}]} [2 3] nil)
-        "cannot remove parent")
-    (is (nil? (disable-remove-from-cart-button? {:id 3 :part-of {:catalogue-item/id 2}} [2 3] nil))
-        "can remove child"))
-  (testing "with parent in cart"
-    (is (nil? (disable-remove-from-cart-button? {:id 2 :children [{:catalogue-item/id 3}]} [2] nil))
-        "can remove item"))
-  (testing "with item and children in cart, and previous entitlement to item"
-    (is (false? (disable-remove-from-cart-button? {:id 2 :children [{:catalogue-item/id 3}]} [2 3] [2]))
-        "can remove item")))
+  (with-redefs [rems.globals/config (atom {:enable-catalogue-hierarchy true})]
+    (testing "without hierarchy"
+      (is (nil? (disable-remove-from-cart-button? {:id 1} [1] nil))
+          "can remove item")
+      (is (nil? (disable-remove-from-cart-button? {:id 1} [1 2 3] nil))
+          "can remove item"))
+    (testing "with item and children in cart"
+      (is (disable-remove-from-cart-button? {:id 2 :children [{:catalogue-item/id 3}]} [2 3] nil)
+          "cannot remove parent")
+      (is (nil? (disable-remove-from-cart-button? {:id 3 :part-of {:catalogue-item/id 2}} [2 3] nil))
+          "can remove child"))
+    (testing "with parent in cart"
+      (is (nil? (disable-remove-from-cart-button? {:id 2 :children [{:catalogue-item/id 3}]} [2] nil))
+          "can remove item"))
+    (testing "with item and children in cart, and previous entitlement to item"
+      (is (false? (disable-remove-from-cart-button? {:id 2 :children [{:catalogue-item/id 3}]} [2 3] [2]))
+          "can remove item"))))
 
 (defn disable-add-to-cart-button? [item cart-item-ids entitlement-catids]
-  (when-let [parent-id (-> item :part-of :catalogue-item/id)]
-    (not (contains? (set/union (set cart-item-ids) (set entitlement-catids))
-                    parent-id))))
+  (when (:enable-catalogue-hierarchy @rems.globals/config)
+    (when-let [parent-id (-> item :part-of :catalogue-item/id)]
+      (not (contains? (set/union (set cart-item-ids) (set entitlement-catids))
+                      parent-id)))))
 
 (deftest test-disable-add-to-cart-button
-  (testing "without hierarchy"
-    (is (nil? (disable-add-to-cart-button? {:id 1} nil nil))
-        "can add to cart"))
-  (testing "with parent, and unrelated item in cart"
-    (is (nil? (disable-add-to-cart-button? {:id 2 :children [{:catalogue-item/id 3}]} [1] nil))
-        "can add to cart"))
-  (testing "with child, without parent in cart"
-    (is (true? (disable-add-to-cart-button? {:id 3 :part-of {:catalogue-item/id 2}} [1] nil))
-        "cannot add to cart"))
-  (testing "with child, and parent in cart"
-    (is (false? (disable-add-to-cart-button? {:id 3 :part-of {:catalogue-item/id 2}} [2] nil))
-        "can add to cart"))
-  (testing "with child, without parent in cart, with entitlement to parent"
-    (is (false? (disable-add-to-cart-button? {:id 3 :part-of {:catalogue-item/id 2}} [1] [2]))
-        "can add to cart")))
+  (with-redefs [rems.globals/config (atom {:enable-catalogue-hierarchy true})]
+    (testing "without hierarchy"
+      (is (nil? (disable-add-to-cart-button? {:id 1} nil nil))
+          "can add to cart"))
+    (testing "with parent, and unrelated item in cart"
+      (is (nil? (disable-add-to-cart-button? {:id 2 :children [{:catalogue-item/id 3}]} [1] nil))
+          "can add to cart"))
+    (testing "with child, without parent in cart"
+      (is (true? (disable-add-to-cart-button? {:id 3 :part-of {:catalogue-item/id 2}} [1] nil))
+          "cannot add to cart"))
+    (testing "with child, and parent in cart"
+      (is (false? (disable-add-to-cart-button? {:id 3 :part-of {:catalogue-item/id 2}} [2] nil))
+          "can add to cart"))
+    (testing "with child, without parent in cart, with entitlement to parent"
+      (is (false? (disable-add-to-cart-button? {:id 3 :part-of {:catalogue-item/id 2}} [1] [2]))
+          "can add to cart"))))
 
 (defn add-to-cart-button
   "Hiccup fragment that contains a button that adds the given item to the cart"
diff --git a/test-config.edn b/test-config.edn
index dcc52ce84..7c28a1f4e 100644
--- a/test-config.edn
+++ b/test-config.edn
@@ -70,5 +70,6 @@
  :enable-doi true
  :enable-duo true
  :enable-catalogue-tree true
+ :enable-catalogue-hierarchy true
  :enable-voting true
  :enable-processing-states true}
diff --git a/test/clj/rems/api/test_applications.clj b/test/clj/rems/api/test_applications.clj
index bc60dfe81..b1d3cea68 100644
--- a/test/clj/rems/api/test_applications.clj
+++ b/test/clj/rems/api/test_applications.clj
@@ -771,7 +771,12 @@
                (api-call :post "/api/applications/create" {:catalogue-item-ids [cat-id-child]} api-key user-id)))
         (is (match? {:success true
                      :application-id number?}
-                    (api-call :post "/api/applications/create" {:catalogue-item-ids [cat-id-parent cat-id-child]} api-key user-id)))))
+                    (api-call :post "/api/applications/create" {:catalogue-item-ids [cat-id-parent cat-id-child]} api-key user-id)))
+        (testing "with hierarchy toggled off"
+          (with-redefs [rems.config/env (assoc rems.config/env :enable-catalogue-hierarchy false)]
+            (is (match? {:success true
+                         :application-id number?}
+                        (api-call :post "/api/applications/create" {:catalogue-item-ids [cat-id-child]} api-key user-id)))))))
 
     (testing "no forms"
       (let [no-form (test-helpers/create-catalogue-item! {:form-id nil})
diff --git a/test/clj/rems/application/test_commands.clj b/test/clj/rems/application/test_commands.clj
index 947ccc9f7..4215e9320 100644
--- a/test/clj/rems/application/test_commands.clj
+++ b/test/clj/rems/application/test_commands.clj
@@ -503,7 +503,9 @@
             :workflow/type :workflow/default}
            (ok-command {:type :application.command/create
                         :actor applicant-user-id
-                        :catalogue-item-ids [8 9]})))
+                        :catalogue-item-ids [8 9]}
+                       nil
+                       (assoc command-injections :get-config (constantly {:enable-catalogue-hierarchy true})))))
     (is (= {:event/type :application.event/created
             :event/actor applicant-user-id
             :event/time (DateTime. 1000)
@@ -516,27 +518,60 @@
             :workflow/type :workflow/default}
            (ok-command {:type :application.command/create
                         :actor applicant-user-id
-                        :catalogue-item-ids [8]})))
-    (is (= {:event/type :application.event/created
-            :event/actor applicant-user-id
-            :event/time (DateTime. 1000)
-            :application/id new-app-id
-            :application/external-id new-external-id
-            :application/resources [{:catalogue-item/id 11, :resource/ext-id "res-complementary-2"}]
-            :application/licenses [{:license/id 1}]
-            :application/forms [{:form/id 1}]
-            :workflow/id 1
-            :workflow/type :workflow/default}
-           (ok-command {:type :application.command/create
-                        :actor applicant-user-id
-                        :catalogue-item-ids [11]}))))
+                        :catalogue-item-ids [8]}
+                       nil
+                       (assoc command-injections :get-config (constantly {:enable-catalogue-hierarchy true})))))
+    (testing "with existing entitlement to top-level resource"
+      (is (= {:event/type :application.event/created
+              :event/actor applicant-user-id
+              :event/time (DateTime. 1000)
+              :application/id new-app-id
+              :application/external-id new-external-id
+              :application/resources [{:catalogue-item/id 11, :resource/ext-id "res-complementary-2"}]
+              :application/licenses [{:license/id 1}]
+              :application/forms [{:form/id 1}]
+              :workflow/id 1
+              :workflow/type :workflow/default}
+             (ok-command {:type :application.command/create
+                          :actor applicant-user-id
+                          :catalogue-item-ids [11]}
+                         nil
+                         (assoc command-injections :get-config (constantly {:enable-catalogue-hierarchy true})))))))
 
   (testing "error: missing top level item"
     (is (= {:errors [{:type :t.applications.errors/missing-top-level-item
                       :catalogue-item-ids [8]}]}
            (fail-command {:type :application.command/create
                           :actor applicant-user-id
-                          :catalogue-item-ids [9]}))))
+                          :catalogue-item-ids [9]}
+                         nil
+                         (assoc command-injections :get-config (constantly {:enable-catalogue-hierarchy true}))))))
+
+  (testing "with hierarchy toggled off"
+    (is (= {:application/external-id new-external-id
+            :application/id new-app-id
+            :event/time (DateTime. 1000)
+            :workflow/type :workflow/default
+            :application/resources [{:catalogue-item/id 9, :resource/ext-id "res-complementary"}]
+            :application/forms [{:form/id 1}]
+            :workflow/id 1
+            :event/actor applicant-user-id
+            :event/type :application.event/created
+            :application/licenses [{:license/id 1}]}
+           (ok-command {:type :application.command/create
+                        :actor applicant-user-id
+                        :catalogue-item-ids [9]})
+           (ok-command {:type :application.command/create
+                        :actor applicant-user-id
+                        :catalogue-item-ids [9]}
+                       nil
+                       command-injections)
+           (ok-command {:type :application.command/create
+                        :actor applicant-user-id
+                        :catalogue-item-ids [9]}
+                       nil
+                       (assoc command-injections :get-config (constantly {:enable-catalogue-hierarchy false}))))
+        "the feature is not used unless config key exists and is truthy"))
 
   (testing "cannot execute the create command for an existing application"
     (reset! allocated-new-ids? false)
diff --git a/test/clj/rems/test_browser.clj b/test/clj/rems/test_browser.clj
index 0abedd69b..ff5f13ab3 100644
--- a/test/clj/rems/test_browser.clj
+++ b/test/clj/rems/test_browser.clj
@@ -625,6 +625,9 @@
               :headers {"x-rems-api-key" "42"
                         "x-rems-user-id" (or userid "handler")}})))
 
+(defn- restart-handler! []
+  (mount/stop #'rems.handler/handler #'rems.main/http-server)
+  (mount/start #'rems.handler/handler #'rems.main/http-server))
 ;;; tests
 
 (deftest test-new-application
@@ -2585,7 +2588,55 @@
                  (into []
                        (map btu/value-of-el)
                        (-> (btu/query [{:class :application-resources}])
-                           (btu/children {:fn/has-class :application-resource}))))))))))
+                           (btu/children {:fn/has-class :application-resource}))))))))
+
+    (testing "with feature flag off"
+      (try
+        (with-redefs [rems.config/env (assoc rems.config/env :enable-catalogue-hierarchy false)]
+          (restart-handler!)
+
+          (testing "admin ui components are not visible"
+            (logout)
+            (login-as "owner")
+
+            (testing "create"
+              (go-to-admin "Catalogue items")
+              (btu/scroll-and-click :create-catalogue-item)
+              (wait-page-title "Create catalogue item – REMS")
+              (btu/wait-page-loaded)
+              (btu/screenshot "create-catalogue-item-when-hierarchy-off")
+              (is (= {}
+                     (select-keys
+                      (slurp-fields :catalogue-item-editor)
+                      ["Complementary items"
+                       "Top-level catalogue item"]))))
+
+            (testing "edit"
+              (btu/go (str (btu/get-server-url) "administration/catalogue-items/edit/" (btu/context-getx :parent-2-id)))
+              (btu/wait-page-loaded)
+              (btu/screenshot "edit-catalogue-item-when-hierarchy-off")
+              (is (= {}
+                     (select-keys
+                      (slurp-fields :catalogue-item-editor)
+                      ["Complementary items"
+                       "Top-level catalogue item"])))))
+
+          (testing "applicant can apply for child item on it's own"
+            (logout)
+            (login-as "alice")
+            (go-to-catalogue)
+            (add-to-cart (btu/context-getx :child-1-title-en))
+            (btu/screenshot "child-in-cart-when-hierarchy-off")
+            (click-cart-apply-single)
+            (wait-page-title (->> (get-application-from-api (get-application-id) "alice")
+                                  :application/external-id
+                                  (format "Application %s – REMS")))
+            (btu/screenshot "application-draft")
+            (send-application)))
+
+        (finally
+          (restart-handler!)
+          (btu/reload))))))
 
 (deftest test-update-catalogue-item
   (btu/with-postmortem
@@ -4269,9 +4320,6 @@
       (rems.db.user-settings/delete-user-settings! "alice")
       (rems.db.user-settings/delete-user-settings! "elsa")))) ; clear language settings
 
-(defn- restart-handler! []
-  (mount/stop #'rems.handler/handler #'rems.main/http-server)
-  (mount/start #'rems.handler/handler #'rems.main/http-server))
 
 (deftest test-hooks
   (btu/with-postmortem

From 5430b701a055a77112e09954118cdc81c3c998dd Mon Sep 17 00:00:00 2001
From: Olli Pikarinen <pikariop@users.noreply.github.com>
Date: Thu, 23 Jul 2026 14:32:36 +0300
Subject: [PATCH 6/6] Fix config documentation

---
 resources/config-defaults.edn | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/resources/config-defaults.edn b/resources/config-defaults.edn
index 67e8bf555..76ee71b79 100644
--- a/resources/config-defaults.edn
+++ b/resources/config-defaults.edn
@@ -425,8 +425,7 @@
  :enable-save-compaction false ; whether to merge consecutive saves into one event (EXPERIMENTAL)
  :enable-autosave false ; whether to automatically save the application as the applicant types (EXPERIMENTAL)
 
- ;; Enable
- ;; See `manual/owner.md` and `docs/architecture/023-catalogue-item-hierarchy.md`
+ ;; Enable catalogue hierarchy. See `manual/owner.md` and `docs/architecture/023-catalogue-item-hierarchy.md`
  :enable-catalogue-hierarchy false
 
  ;; Extended logging for routes that should additionally log content of entity mutation.