diff --git a/frontend/src/app/shared/components/fields/display/display-field.initializer.ts b/frontend/src/app/shared/components/fields/display/display-field.initializer.ts
index 7b38b7ad928..a1a84fd82f9 100644
--- a/frontend/src/app/shared/components/fields/display/display-field.initializer.ts
+++ b/frontend/src/app/shared/components/fields/display/display-field.initializer.ts
@@ -107,6 +107,7 @@ export function initializeCoreDisplayFields(displayFieldService:DisplayFieldServ
         'TimeEntriesActivity',
         'Version',
         'Category',
+        'BacklogBucket',
         'Sprint',
         'CustomField::Hierarchy::Item',
         'CustomOption',
diff --git a/frontend/src/app/shared/components/fields/edit/edit-field.initializer.ts b/frontend/src/app/shared/components/fields/edit/edit-field.initializer.ts
index 118b58bdb88..a8c953547e3 100644
--- a/frontend/src/app/shared/components/fields/edit/edit-field.initializer.ts
+++ b/frontend/src/app/shared/components/fields/edit/edit-field.initializer.ts
@@ -100,6 +100,7 @@ export function initializeCoreEditFields(editFieldService:EditFieldService, sele
         'Version',
         'TimeEntriesActivity',
         'Category',
+        'BacklogBucket',
         'Sprint',
         'CustomOption',
         'CustomField::Hierarchy::Item',
diff --git a/modules/backlogs/app/models/queries/backlog_buckets.rb b/modules/backlogs/app/models/queries/backlog_buckets.rb
new file mode 100644
index 00000000000..62cf00316f2
--- /dev/null
+++ b/modules/backlogs/app/models/queries/backlog_buckets.rb
@@ -0,0 +1,35 @@
+# frozen_string_literal: true
+
+# -- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See COPYRIGHT and LICENSE files for more details.
+# ++
+
+module Queries::BacklogBuckets
+  ::Queries::Register.register(BacklogBucketQuery) do
+    order Orders::DefaultOrder
+  end
+end
diff --git a/modules/backlogs/app/models/queries/backlog_buckets/backlog_bucket_query.rb b/modules/backlogs/app/models/queries/backlog_buckets/backlog_bucket_query.rb
new file mode 100644
index 00000000000..33e2f2289db
--- /dev/null
+++ b/modules/backlogs/app/models/queries/backlog_buckets/backlog_bucket_query.rb
@@ -0,0 +1,46 @@
+# frozen_string_literal: true
+
+# -- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See COPYRIGHT and LICENSE files for more details.
+# ++
+
+module Queries
+  module BacklogBuckets
+    class BacklogBucketQuery
+      include ::Queries::BaseQuery
+      include ::Queries::UnpersistedQuery
+
+      def self.model
+        ::BacklogBucket
+      end
+
+      def default_scope
+        ::BacklogBucket.visible(User.current)
+      end
+    end
+  end
+end
diff --git a/modules/backlogs/app/models/queries/backlog_buckets/orders/default_order.rb b/modules/backlogs/app/models/queries/backlog_buckets/orders/default_order.rb
new file mode 100644
index 00000000000..30311b27dd4
--- /dev/null
+++ b/modules/backlogs/app/models/queries/backlog_buckets/orders/default_order.rb
@@ -0,0 +1,37 @@
+# frozen_string_literal: true
+
+# -- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See COPYRIGHT and LICENSE files for more details.
+# ++
+
+class Queries::BacklogBuckets::Orders::DefaultOrder < Queries::Orders::Base
+  self.model = BacklogBucket
+
+  def self.key
+    /\A(id|name)\z/
+  end
+end
diff --git a/modules/backlogs/lib/api/v3/backlog_buckets/backlog_bucket_collection_representer.rb b/modules/backlogs/lib/api/v3/backlog_buckets/backlog_bucket_collection_representer.rb
new file mode 100644
index 00000000000..23724dad31a
--- /dev/null
+++ b/modules/backlogs/lib/api/v3/backlog_buckets/backlog_bucket_collection_representer.rb
@@ -0,0 +1,38 @@
+# frozen_string_literal: true
+
+# -- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See COPYRIGHT and LICENSE files for more details.
+# ++
+
+module API
+  module V3
+    module BacklogBuckets
+      class BacklogBucketCollectionRepresenter < ::API::Decorators::OffsetPaginatedCollection
+      end
+    end
+  end
+end
diff --git a/modules/backlogs/lib/api/v3/backlog_buckets/backlog_bucket_representer.rb b/modules/backlogs/lib/api/v3/backlog_buckets/backlog_bucket_representer.rb
new file mode 100644
index 00000000000..ca29a4d75e0
--- /dev/null
+++ b/modules/backlogs/lib/api/v3/backlog_buckets/backlog_bucket_representer.rb
@@ -0,0 +1,61 @@
+# frozen_string_literal: true
+
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See COPYRIGHT and LICENSE files for more details.
+#++
+
+require "roar/decorator"
+require "roar/json/hal"
+
+module API
+  module V3
+    module BacklogBuckets
+      class BacklogBucketRepresenter < ::API::Decorators::Single
+        include API::Decorators::LinkedResource
+        include API::V3::Workspaces::LinkedResource
+        include API::Decorators::DateProperty
+
+        self_link
+
+        associated_project as: :definingWorkspace
+
+        property :id,
+                 render_nil: true
+
+        property :name,
+                 render_nil: true
+
+        date_time_property :created_at
+        date_time_property :updated_at
+
+        def _type
+          "BacklogBucket"
+        end
+      end
+    end
+  end
+end
diff --git a/modules/backlogs/lib/api/v3/backlog_buckets/backlog_buckets_api.rb b/modules/backlogs/lib/api/v3/backlog_buckets/backlog_buckets_api.rb
new file mode 100644
index 00000000000..c7621343206
--- /dev/null
+++ b/modules/backlogs/lib/api/v3/backlog_buckets/backlog_buckets_api.rb
@@ -0,0 +1,51 @@
+# frozen_string_literal: true
+
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See COPYRIGHT and LICENSE files for more details.
+#++
+
+module API
+  module V3
+    module BacklogBuckets
+      class BacklogBucketsAPI < ::API::OpenProjectAPI
+        resources :backlog_buckets do
+          get &::API::V3::Utilities::Endpoints::Index
+                 .new(model: BacklogBucket)
+                 .mount
+
+          route_param :id, type: Integer, desc: "Backlog Bucket ID" do
+            after_validation do
+              @backlog_bucket = BacklogBucket.visible(current_user).find(params[:id])
+            end
+
+            get &::API::V3::Utilities::Endpoints::Show.new(model: BacklogBucket).mount
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/modules/backlogs/lib/api/v3/backlog_buckets/backlog_buckets_by_project_api.rb b/modules/backlogs/lib/api/v3/backlog_buckets/backlog_buckets_by_project_api.rb
new file mode 100644
index 00000000000..a926b9aaccb
--- /dev/null
+++ b/modules/backlogs/lib/api/v3/backlog_buckets/backlog_buckets_by_project_api.rb
@@ -0,0 +1,50 @@
+# frozen_string_literal: true
+
+# -- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See COPYRIGHT and LICENSE files for more details.
+# ++
+
+module API
+  module V3
+    module BacklogBuckets
+      class BacklogBucketsByProjectAPI < ::API::OpenProjectAPI
+        resources :backlog_buckets do
+          after_validation do
+            authorize_in_project(:view_sprints, project: @project)
+          end
+
+          get &::API::V3::Utilities::Endpoints::Index
+                 .new(
+                   model: BacklogBucket,
+                   scope: -> { BacklogBucket.where(project: @project).visible.order_alphabetically }
+                 )
+                 .mount
+        end
+      end
+    end
+  end
+end
diff --git a/modules/backlogs/lib/open_project/backlogs/engine.rb b/modules/backlogs/lib/open_project/backlogs/engine.rb
index 85f0baa0baa..442274a2339 100644
--- a/modules/backlogs/lib/open_project/backlogs/engine.rb
+++ b/modules/backlogs/lib/open_project/backlogs/engine.rb
@@ -173,12 +173,26 @@ module OpenProject::Backlogs
       "#{root}/projects/#{id}/sprints"
     end
 
+    add_api_path :backlog_buckets do
+      "#{root}/backlog_buckets"
+    end
+
+    add_api_path :backlog_bucket do |id|
+      "#{root}/backlog_buckets/#{id}"
+    end
+
+    add_api_path :project_backlog_buckets do |id|
+      "#{root}/projects/#{id}/backlog_buckets"
+    end
+
     add_api_endpoint "API::V3::Root" do
       mount ::API::V3::Sprints::SprintsAPI
+      mount ::API::V3::BacklogBuckets::BacklogBucketsAPI
     end
 
     add_api_endpoint "API::V3::Projects::ProjectsAPI", :id do
       mount ::API::V3::Sprints::SprintsByProjectAPI
+      mount ::API::V3::BacklogBuckets::BacklogBucketsByProjectAPI
     end
 
     initializer "openproject_backlogs.event_subscriptions" do
@@ -224,9 +238,16 @@ module OpenProject::Backlogs
         ::Type.add_constraint attribute, ->(_type, project: nil) { project.nil? || project.backlogs_enabled? }
       end
 
+      story_and_sprint_permission = ->(_type, project: nil) do
+        project.nil? || User.current.allowed_in_project?(:view_sprints, project)
+      end
+
+      ::Type.add_constraint :backlog_bucket, story_and_sprint_permission
+
       ::Type.add_default_mapping(:estimates_and_progress, :story_points)
       ::Type.add_default_mapping(:other, :position)
       ::Type.add_default_mapping(:details, :sprint)
+      ::Type.add_default_mapping(:details, :backlog_bucket)
 
       ::Queries::Register.register(::Query) do
         filter Queries::WorkPackages::Filter::SprintFilter
diff --git a/modules/backlogs/lib/open_project/backlogs/patches/api/work_package_representer.rb b/modules/backlogs/lib/open_project/backlogs/patches/api/work_package_representer.rb
index 6b9783ce1f3..40439ffd5d8 100644
--- a/modules/backlogs/lib/open_project/backlogs/patches/api/work_package_representer.rb
+++ b/modules/backlogs/lib/open_project/backlogs/patches/api/work_package_representer.rb
@@ -72,6 +72,33 @@ module OpenProject::Backlogs
                        end
                      end,
                      setter: associated_resource_default_setter(:sprint, :sprint, :sprint)
+
+            resource :backlog_bucket,
+                     link_cache_if: ->(*) {
+                       represented.project.present? &&
+                         current_user.allowed_in_project?(:view_sprints, represented.project)
+                     },
+                     link: ->(*) {
+                       if represented.backlog_bucket.present?
+                         {
+                           href: api_v3_paths.backlog_bucket(represented.backlog_bucket_id),
+                           title: represented.backlog_bucket.name
+                         }
+                       else
+                         {
+                           href: nil
+                         }
+                       end
+                     },
+                     getter: ->(*) do
+                       if embed_links &&
+                          represented.project.present? &&
+                          represented.backlog_bucket.present? &&
+                          current_user.allowed_in_project?(:view_sprints, represented.project)
+                         ::API::V3::BacklogBuckets::BacklogBucketRepresenter.create(represented.backlog_bucket, current_user:)
+                       end
+                     end,
+                     setter: associated_resource_default_setter(:backlog_bucket, :backlog_bucket, :backlog_bucket)
           end
         end
       end
diff --git a/modules/backlogs/lib/open_project/backlogs/patches/api/work_package_schema_representer.rb b/modules/backlogs/lib/open_project/backlogs/patches/api/work_package_schema_representer.rb
index 813790bd4d7..bb9f518da85 100644
--- a/modules/backlogs/lib/open_project/backlogs/patches/api/work_package_schema_representer.rb
+++ b/modules/backlogs/lib/open_project/backlogs/patches/api/work_package_schema_representer.rb
@@ -67,6 +67,20 @@ module OpenProject::Backlogs
                                        "#{api_v3_paths.project_sprints(represented.project_id)}?filters=#{filters}&pageSize=-1"
                                      }
 
+            schema_with_allowed_link :backlog_bucket,
+                                     has_default: false,
+                                     required: false,
+                                     show_if: ->(*) {
+                                       current_user.allowed_in_project?(:view_sprints, represented.project) &&
+                                         backlogs_constraint_passed?(:backlog_bucket)
+                                     },
+                                     href_callback: ->(*) {
+                                       filters = CGI.escape(JSON.dump([]))
+                                       query = "filters=#{filters}&pageSize=-1"
+
+                                       "#{api_v3_paths.project_backlog_buckets(represented.project_id)}?#{query}"
+                                     }
+
             define_method :backlogs_constraint_passed? do |attribute|
               !represented.type || represented.type.passes_attribute_constraint?(attribute, project: represented.project)
             end
diff --git a/modules/backlogs/spec/lib/api/v3/backlog_buckets/backlog_bucket_representer_rendering_spec.rb b/modules/backlogs/spec/lib/api/v3/backlog_buckets/backlog_bucket_representer_rendering_spec.rb
new file mode 100644
index 00000000000..9389f227950
--- /dev/null
+++ b/modules/backlogs/spec/lib/api/v3/backlog_buckets/backlog_bucket_representer_rendering_spec.rb
@@ -0,0 +1,103 @@
+# frozen_string_literal: true
+
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See COPYRIGHT and LICENSE files for more details.
+#++
+
+require "spec_helper"
+
+RSpec.describe API::V3::BacklogBuckets::BacklogBucketRepresenter, "rendering" do
+  include API::V3::Utilities::PathHelper
+
+  let(:workspace) { build_stubbed(:project) }
+  let(:backlog_bucket) { build_stubbed(:backlog_bucket, name: "My Bucket", project: workspace) }
+  let(:current_user) { build_stubbed(:user) }
+  let(:embed_links) { true }
+  let(:representer) { described_class.create(backlog_bucket, current_user:, embed_links:) }
+
+  subject(:generated) { representer.to_json }
+
+  it { is_expected.to include_json("BacklogBucket".to_json).at_path("_type") }
+
+  describe "links" do
+    it { is_expected.to have_json_type(Object).at_path("_links") }
+
+    describe "self" do
+      it_behaves_like "has a titled link" do
+        let(:link) { "self" }
+        let(:href) { api_v3_paths.backlog_bucket(backlog_bucket.id) }
+        let(:title) { backlog_bucket.name }
+      end
+    end
+
+    describe "definingWorkspace" do
+      it_behaves_like "has workspace linked" do
+        let(:link) { "definingWorkspace" }
+      end
+    end
+  end
+
+  describe "properties" do
+    describe "_type" do
+      it_behaves_like "property", :_type do
+        let(:value) { "BacklogBucket" }
+      end
+    end
+
+    describe "id" do
+      it_behaves_like "property", :id do
+        let(:value) { backlog_bucket.id }
+      end
+    end
+
+    describe "name" do
+      it_behaves_like "property", :name do
+        let(:value) { backlog_bucket.name }
+      end
+    end
+
+    describe "createdAt" do
+      it_behaves_like "has UTC ISO 8601 date and time" do
+        let(:date) { backlog_bucket.created_at }
+        let(:json_path) { "createdAt" }
+      end
+    end
+
+    describe "updatedAt" do
+      it_behaves_like "has UTC ISO 8601 date and time" do
+        let(:date) { backlog_bucket.updated_at }
+        let(:json_path) { "updatedAt" }
+      end
+    end
+  end
+
+  describe "embedded" do
+    it_behaves_like "has workspace embedded" do
+      let(:embedded_path) { "_embedded/definingWorkspace" }
+    end
+  end
+end
diff --git a/modules/backlogs/spec/lib/api/v3/work_packages/schema/work_package_schema_representer_spec.rb b/modules/backlogs/spec/lib/api/v3/work_packages/schema/work_package_schema_representer_spec.rb
index fab1ec92809..ca81938fddf 100644
--- a/modules/backlogs/spec/lib/api/v3/work_packages/schema/work_package_schema_representer_spec.rb
+++ b/modules/backlogs/spec/lib/api/v3/work_packages/schema/work_package_schema_representer_spec.rb
@@ -161,4 +161,28 @@ RSpec.describe API::V3::WorkPackages::Schema::WorkPackageSchemaRepresenter do
       end
     end
   end
+
+  describe "backlogBucket" do
+    let(:path) { "backlogBucket" }
+
+    it_behaves_like "has basic schema properties" do
+      let(:type) { "BacklogBucket" }
+      let(:name) { I18n.t("activerecord.attributes.work_package.backlog_bucket") }
+      let(:required) { false }
+      let(:writable) { true }
+      let(:location) { "_links" }
+    end
+
+    it_behaves_like "links to allowed values via collection link" do
+      let(:href) { "#{api_v3_paths.project_backlog_buckets(project.id)}?filters=%5B%5D&pageSize=-1" }
+    end
+
+    context "when lacking permission to see the sprints (or if backlogs is disabled)" do
+      let(:permissions) { %i(view_work_packages edit_work_packages) }
+
+      it "has no reference to the backlog bucket" do
+        expect(subject).not_to have_json_path(path)
+      end
+    end
+  end
 end
diff --git a/modules/backlogs/spec/lib/api/v3/work_packages/work_package_representer_rendering_spec.rb b/modules/backlogs/spec/lib/api/v3/work_packages/work_package_representer_rendering_spec.rb
index b6af7bd445b..fdc2e4382c1 100644
--- a/modules/backlogs/spec/lib/api/v3/work_packages/work_package_representer_rendering_spec.rb
+++ b/modules/backlogs/spec/lib/api/v3/work_packages/work_package_representer_rendering_spec.rb
@@ -41,7 +41,8 @@ RSpec.describe API::V3::WorkPackages::WorkPackageRepresenter, "rendering" do
                   project:,
                   story_points:,
                   position:,
-                  sprint:)
+                  sprint:,
+                  backlog_bucket:)
   end
   let(:type) { build_stubbed(:type) }
   let(:enabled_module_names) { %w[backlogs] }
@@ -52,6 +53,7 @@ RSpec.describe API::V3::WorkPackages::WorkPackageRepresenter, "rendering" do
   let(:story_points) { 23 }
   let(:position) { 123 }
   let(:sprint) { build_stubbed(:sprint) }
+  let(:backlog_bucket) { build_stubbed(:backlog_bucket) }
   let(:embed_links) { true }
   let(:representer) do
     described_class.create(work_package, current_user:, embed_links:)
@@ -119,6 +121,34 @@ RSpec.describe API::V3::WorkPackages::WorkPackageRepresenter, "rendering" do
       end
     end
 
+    describe "backlogBucket" do
+      let(:link) { "backlogBucket" }
+      let(:href) { api_v3_paths.backlog_bucket(backlog_bucket.id) }
+      let(:title) { backlog_bucket.name }
+
+      it_behaves_like "has a titled link"
+
+      context "when lacking the permission" do
+        let(:permissions) { [] }
+
+        it_behaves_like "has no link"
+      end
+
+      context "when the project is empty (because the work package is not persisted yet)" do
+        let(:project) { nil }
+
+        it_behaves_like "has no link"
+      end
+
+      context "when the work package has no backlog bucket assigned" do
+        let(:backlog_bucket) { nil }
+
+        it_behaves_like "has an empty link" do
+          let(:link) { "backlogBucket" }
+        end
+      end
+    end
+
     describe "update links" do
       context "when user lacks edit permission but has manage_sprint_items" do
         let(:permissions) { super() + [:manage_sprint_items] }
@@ -150,5 +180,25 @@ RSpec.describe API::V3::WorkPackages::WorkPackageRepresenter, "rendering" do
         it_behaves_like "has the resource not embedded"
       end
     end
+
+    describe "backlogBucket" do
+      let(:embedded_path) { "_embedded/backlogBucket" }
+      let(:embedded_resource) { backlog_bucket }
+      let(:embedded_resource_type) { "BacklogBucket" }
+
+      it_behaves_like "has the resource embedded"
+
+      context "when lacking the permission" do
+        let(:permissions) { [] }
+
+        it_behaves_like "has the resource not embedded"
+      end
+
+      context "when the work package has no backlog bucket assigned" do
+        let(:backlog_bucket) { nil }
+
+        it_behaves_like "has the resource not embedded"
+      end
+    end
   end
 end
diff --git a/modules/backlogs/spec/requests/api/v3/backlog_buckets/index_resource_spec.rb b/modules/backlogs/spec/requests/api/v3/backlog_buckets/index_resource_spec.rb
new file mode 100644
index 00000000000..a3ccc243e6f
--- /dev/null
+++ b/modules/backlogs/spec/requests/api/v3/backlog_buckets/index_resource_spec.rb
@@ -0,0 +1,90 @@
+# frozen_string_literal: true
+
+# -- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See COPYRIGHT and LICENSE files for more details.
+# ++
+
+require "spec_helper"
+require "rack/test"
+
+RSpec.describe "API v3 BacklogBucket resource", content_type: :json do
+  include Rack::Test::Methods
+  include API::V3::Utilities::PathHelper
+
+  shared_let(:project) { create(:project, public: false) }
+  shared_let(:other_project) { create(:project, public: false) }
+  shared_let(:project_without_permission) { create(:project, public: false) }
+
+  shared_let(:bucket) { create(:backlog_bucket, project:) }
+  shared_let(:other_bucket) { create(:backlog_bucket, project: other_project) }
+  shared_let(:bucket_without_permission) { create(:backlog_bucket, project: project_without_permission) }
+
+  let(:permissions) { %i[view_sprints] }
+
+  current_user do
+    create(:user,
+           member_with_permissions: {
+             project => permissions,
+             other_project => permissions
+           })
+  end
+
+  describe "GET /api/v3/backlog_buckets" do
+    let(:get_path) { api_v3_paths.path_for(:backlog_buckets, page_size:, offset:) }
+    let(:page_size) { nil }
+    let(:offset) { nil }
+
+    before { get get_path }
+
+    context "for a user with view_sprints permission" do
+      it_behaves_like "API V3 collection response", 2, 2, "BacklogBucket" do
+        let(:elements) { [other_bucket, bucket] }
+      end
+    end
+
+    context "for a user without view_sprints permission" do
+      let(:permissions) { [] }
+
+      it_behaves_like "API V3 collection response", 0, 0, "BacklogBucket"
+    end
+
+    context "for an anonymous user" do
+      let(:current_user) { User.anonymous }
+
+      it_behaves_like "unauthenticated access"
+    end
+
+    context "with pagination" do
+      let(:page_size) { 1 }
+      let(:offset) { 2 }
+
+      it_behaves_like "API V3 collection response", 2, 1, "BacklogBucket" do
+        let(:elements) { [bucket] }
+      end
+    end
+  end
+end
diff --git a/modules/backlogs/spec/requests/api/v3/backlog_buckets/project_index_resource_spec.rb b/modules/backlogs/spec/requests/api/v3/backlog_buckets/project_index_resource_spec.rb
new file mode 100644
index 00000000000..60a2e3651b0
--- /dev/null
+++ b/modules/backlogs/spec/requests/api/v3/backlog_buckets/project_index_resource_spec.rb
@@ -0,0 +1,72 @@
+# frozen_string_literal: true
+
+# -- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See COPYRIGHT and LICENSE files for more details.
+# ++
+
+require "spec_helper"
+
+RSpec.describe "API v3 BacklogBucket resource on project", content_type: :json do
+  include Rack::Test::Methods
+  include API::V3::Utilities::PathHelper
+
+  shared_let(:project) { create(:project, public: false) }
+  shared_let(:other_project) { create(:project, public: false) }
+
+  shared_let(:bucket) { create(:backlog_bucket, project:) }
+  shared_let(:other_bucket) { create(:backlog_bucket, project: other_project) }
+
+  let(:permissions) { %i[view_sprints] }
+
+  current_user do
+    create(:user, member_with_permissions: { project => permissions })
+  end
+
+  describe "GET /api/v3/projects/:id/backlog_buckets" do
+    let(:get_path) { api_v3_paths.project_backlog_buckets(project.id) }
+
+    before { get get_path }
+
+    context "for a user with view_sprints permission" do
+      it_behaves_like "API V3 collection response", 1, 1, "BacklogBucket" do
+        let(:elements) { [bucket] }
+      end
+    end
+
+    context "for a user without view_sprints permission" do
+      let(:permissions) { [] }
+
+      it_behaves_like "unauthorized access"
+    end
+
+    context "for a user being not a project member at all" do
+      let(:get_path) { api_v3_paths.project_backlog_buckets(other_project.id) }
+
+      it_behaves_like "not found"
+    end
+  end
+end
diff --git a/modules/backlogs/spec/requests/api/v3/backlog_buckets/show_resource_spec.rb b/modules/backlogs/spec/requests/api/v3/backlog_buckets/show_resource_spec.rb
new file mode 100644
index 00000000000..4b03f2c04b0
--- /dev/null
+++ b/modules/backlogs/spec/requests/api/v3/backlog_buckets/show_resource_spec.rb
@@ -0,0 +1,74 @@
+# frozen_string_literal: true
+
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See COPYRIGHT and LICENSE files for more details.
+#++
+
+require "rack/test"
+require "spec_helper"
+
+RSpec.describe "API v3 BacklogBucket resource", content_type: :json do
+  include Rack::Test::Methods
+  include API::V3::Utilities::PathHelper
+
+  shared_let(:project) { create(:project, public: false) }
+  shared_let(:bucket) { create(:backlog_bucket, project:) }
+
+  let(:permissions) { %i[view_sprints] }
+
+  current_user do
+    create(:user, member_with_permissions: { project => permissions })
+  end
+
+  describe "GET /api/v3/backlog_buckets/:id" do
+    let(:get_path) { api_v3_paths.backlog_bucket(bucket.id) }
+
+    before { get get_path }
+
+    context "for a user with view_sprints permission" do
+      it_behaves_like "successful response", 200, "BacklogBucket"
+    end
+
+    context "for a user without view_sprints permission" do
+      let(:permissions) { [] }
+
+      it_behaves_like "not found"
+    end
+
+    context "for an anonymous user" do
+      let(:current_user) { User.anonymous }
+
+      it_behaves_like "unauthenticated access"
+    end
+
+    context "for a bucket that does not exist" do
+      let(:get_path) { api_v3_paths.backlog_bucket(0) }
+
+      it_behaves_like "not found"
+    end
+  end
+end