diff --git a/app/controllers/api/v2_alpha/notifications/accounts_controller.rb b/app/controllers/api/v2/notifications/accounts_controller.rb
similarity index 77%
rename from app/controllers/api/v2_alpha/notifications/accounts_controller.rb
rename to app/controllers/api/v2/notifications/accounts_controller.rb
index 9933b63373e1fc09f049467e5eb0b369db1d5f1b..771e966388347981fa6adfe878f81343ebaa6ce2 100644
--- a/app/controllers/api/v2_alpha/notifications/accounts_controller.rb
+++ b/app/controllers/api/v2/notifications/accounts_controller.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class Api::V2Alpha::Notifications::AccountsController < Api::BaseController
+class Api::V2::Notifications::AccountsController < Api::BaseController
   before_action -> { doorkeeper_authorize! :read, :'read:notifications' }
   before_action :require_user!
   before_action :set_notifications!
@@ -33,11 +33,11 @@ class Api::V2Alpha::Notifications::AccountsController < Api::BaseController
   end
 
   def next_path
-    api_v2_alpha_notification_accounts_url pagination_params(max_id: pagination_max_id) if records_continue?
+    api_v2_notification_accounts_url pagination_params(max_id: pagination_max_id) if records_continue?
   end
 
   def prev_path
-    api_v2_alpha_notification_accounts_url pagination_params(min_id: pagination_since_id) unless @paginated_notifications.empty?
+    api_v2_notification_accounts_url pagination_params(min_id: pagination_since_id) unless @paginated_notifications.empty?
   end
 
   def pagination_collection
diff --git a/app/controllers/api/v2_alpha/notifications_controller.rb b/app/controllers/api/v2/notifications_controller.rb
similarity index 89%
rename from app/controllers/api/v2_alpha/notifications_controller.rb
rename to app/controllers/api/v2/notifications_controller.rb
index e8aa0b9e4987771cd0c1502aaf29222198d4e4d1..c070c0e5e718928c4faa8c628e3261995a2a1f14 100644
--- a/app/controllers/api/v2_alpha/notifications_controller.rb
+++ b/app/controllers/api/v2/notifications_controller.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class Api::V2Alpha::NotificationsController < Api::BaseController
+class Api::V2::NotificationsController < Api::BaseController
   before_action -> { doorkeeper_authorize! :read, :'read:notifications' }, except: [:clear, :dismiss]
   before_action -> { doorkeeper_authorize! :write, :'write:notifications' }, only: [:clear, :dismiss]
   before_action :require_user!
@@ -21,7 +21,7 @@ class Api::V2Alpha::NotificationsController < Api::BaseController
       ActiveRecord::Associations::Preloader.new(records: @presenter.accounts, associations: [:account_stat, { user: :role }]).call
     end
 
-    MastodonOTELTracer.in_span('Api::V2Alpha::NotificationsController#index rendering') do |span|
+    MastodonOTELTracer.in_span('Api::V2::NotificationsController#index rendering') do |span|
       statuses = @grouped_notifications.filter_map { |group| group.target_status&.id }
 
       span.add_attributes(
@@ -64,7 +64,7 @@ class Api::V2Alpha::NotificationsController < Api::BaseController
   private
 
   def load_notifications
-    MastodonOTELTracer.in_span('Api::V2Alpha::NotificationsController#load_notifications') do
+    MastodonOTELTracer.in_span('Api::V2::NotificationsController#load_notifications') do
       notifications = browserable_account_notifications.includes(from_account: [:account_stat, :user]).to_a_grouped_paginated_by_id(
         limit_param(DEFAULT_NOTIFICATIONS_LIMIT),
         params.slice(:max_id, :since_id, :min_id, :grouped_types).permit(:max_id, :since_id, :min_id, grouped_types: [])
@@ -79,7 +79,7 @@ class Api::V2Alpha::NotificationsController < Api::BaseController
   def load_grouped_notifications
     return [] if @notifications.empty?
 
-    MastodonOTELTracer.in_span('Api::V2Alpha::NotificationsController#load_grouped_notifications') do
+    MastodonOTELTracer.in_span('Api::V2::NotificationsController#load_grouped_notifications') do
       NotificationGroup.from_notifications(@notifications, pagination_range: (@notifications.last.id)..(@notifications.first.id), grouped_types: params[:grouped_types])
     end
   end
@@ -101,11 +101,11 @@ class Api::V2Alpha::NotificationsController < Api::BaseController
   end
 
   def next_path
-    api_v2_alpha_notifications_url pagination_params(max_id: pagination_max_id) unless @notifications.empty?
+    api_v2_notifications_url pagination_params(max_id: pagination_max_id) unless @notifications.empty?
   end
 
   def prev_path
-    api_v2_alpha_notifications_url pagination_params(min_id: pagination_since_id) unless @notifications.empty?
+    api_v2_notifications_url pagination_params(min_id: pagination_since_id) unless @notifications.empty?
   end
 
   def pagination_collection
diff --git a/app/javascript/mastodon/api/notifications.ts b/app/javascript/mastodon/api/notifications.ts
index e34dc85bb0d4a4f10a11a0a7585c2d47a8d2062f..24d526655cefc443a82829f36fdd16188462543c 100644
--- a/app/javascript/mastodon/api/notifications.ts
+++ b/app/javascript/mastodon/api/notifications.ts
@@ -37,7 +37,7 @@ export const apiFetchNotificationGroups = async (params?: {
 }) => {
   const response = await api().request<ApiNotificationGroupsResultJSON>({
     method: 'GET',
-    url: '/api/v2_alpha/notifications',
+    url: '/api/v2/notifications',
     params,
   });
 
diff --git a/app/serializers/rest/instance_serializer.rb b/app/serializers/rest/instance_serializer.rb
index cced83587d073641ae2321b1f9962925d6b21de2..19361277ae4dde1fc8d51ccd32191a10219fb705 100644
--- a/app/serializers/rest/instance_serializer.rb
+++ b/app/serializers/rest/instance_serializer.rb
@@ -108,9 +108,7 @@ class REST::InstanceSerializer < ActiveModel::Serializer
   end
 
   def api_versions
-    {
-      mastodon: 1,
-    }
+    Mastodon::Version.api_versions
   end
 
   private
diff --git a/config/routes/api.rb b/config/routes/api.rb
index df975065bd7bdc8d6b10ae97d8cb630d2ad7d317..b237791736f8725edb3f8c1d13c24143e8b10b25 100644
--- a/config/routes/api.rb
+++ b/config/routes/api.rb
@@ -316,6 +316,21 @@ namespace :api, format: false do
     end
   end
 
+  concern :grouped_notifications do
+    resources :notifications, param: :group_key, only: [:index, :show] do
+      collection do
+        post :clear
+        get :unread_count
+      end
+
+      member do
+        post :dismiss
+      end
+
+      resources :accounts, only: [:index], module: :notifications
+    end
+  end
+
   namespace :v2 do
     get '/search', to: 'search#index', as: :search
 
@@ -341,21 +356,12 @@ namespace :api, format: false do
     namespace :notifications do
       resource :policy, only: [:show, :update]
     end
-  end
-
-  namespace :v2_alpha do
-    resources :notifications, param: :group_key, only: [:index, :show] do
-      collection do
-        post :clear
-        get :unread_count
-      end
 
-      member do
-        post :dismiss
-      end
+    concerns :grouped_notifications
+  end
 
-      resources :accounts, only: [:index], module: :notifications
-    end
+  namespace :v2_alpha, module: 'v2' do
+    concerns :grouped_notifications
   end
 
   namespace :web do
diff --git a/lib/mastodon/version.rb b/lib/mastodon/version.rb
index caafa96b361b298d544e716b5841df74cd5cd462..00e6160890beb2db3a41f4bfa7c42fb06a0e434d 100644
--- a/lib/mastodon/version.rb
+++ b/lib/mastodon/version.rb
@@ -43,6 +43,12 @@ module Mastodon
       @gem_version ||= Gem::Version.new(to_s.split('+')[0])
     end
 
+    def api_versions
+      {
+        mastodon: 2,
+      }
+    end
+
     def repository
       ENV.fetch('GITHUB_REPOSITORY', 'mastodon/mastodon')
     end
diff --git a/spec/requests/api/v2_alpha/notifications/accounts_spec.rb b/spec/requests/api/v2/notifications/accounts_spec.rb
similarity index 84%
rename from spec/requests/api/v2_alpha/notifications/accounts_spec.rb
rename to spec/requests/api/v2/notifications/accounts_spec.rb
index 3c5bcd89963dff33ce0a169cb6ed76ca5f82d0ed..102b009c0b9f4a98c49358be14362f3ded7be3a6 100644
--- a/spec/requests/api/v2_alpha/notifications/accounts_spec.rb
+++ b/spec/requests/api/v2/notifications/accounts_spec.rb
@@ -8,9 +8,9 @@ RSpec.describe 'Accounts in grouped notifications' do
   let(:scopes)  { 'read:notifications write:notifications' }
   let(:headers) { { 'Authorization' => "Bearer #{token.token}" } }
 
-  describe 'GET /api/v2_alpha/notifications/:group_key/accounts', :inline_jobs do
+  describe 'GET /api/v2/notifications/:group_key/accounts', :inline_jobs do
     subject do
-      get "/api/v2_alpha/notifications/#{user.account.notifications.first.group_key}/accounts", headers: headers, params: params
+      get "/api/v2/notifications/#{user.account.notifications.first.group_key}/accounts", headers: headers, params: params
     end
 
     let(:params) { {} }
@@ -71,8 +71,8 @@ RSpec.describe 'Accounts in grouped notifications' do
 
         expect(response)
           .to include_pagination_headers(
-            prev: api_v2_alpha_notification_accounts_url(limit: params[:limit], min_id: notifications.first.id),
-            next: api_v2_alpha_notification_accounts_url(limit: params[:limit], max_id: notifications.second.id)
+            prev: api_v2_notification_accounts_url(limit: params[:limit], min_id: notifications.first.id),
+            next: api_v2_notification_accounts_url(limit: params[:limit], max_id: notifications.second.id)
           )
       end
     end
diff --git a/spec/requests/api/v2/notifications_spec.rb b/spec/requests/api/v2/notifications_spec.rb
new file mode 100644
index 0000000000000000000000000000000000000000..edf333ecd855865833279aa65ac07047008da182
--- /dev/null
+++ b/spec/requests/api/v2/notifications_spec.rb
@@ -0,0 +1,343 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe 'Notifications' do
+  let(:user)    { Fabricate(:user, account_attributes: { username: 'alice' }) }
+  let(:token)   { Fabricate(:accessible_access_token, resource_owner_id: user.id, scopes: scopes) }
+  let(:scopes)  { 'read:notifications write:notifications' }
+  let(:headers) { { 'Authorization' => "Bearer #{token.token}" } }
+
+  describe 'GET /api/v2/notifications/unread_count', :inline_jobs do
+    subject do
+      get '/api/v2/notifications/unread_count', headers: headers, params: params
+    end
+
+    let(:params) { {} }
+
+    before do
+      first_status = PostStatusService.new.call(user.account, text: 'Test')
+      ReblogService.new.call(Fabricate(:account), first_status)
+      PostStatusService.new.call(Fabricate(:account), text: 'Hello @alice')
+      FavouriteService.new.call(Fabricate(:account), first_status)
+      FavouriteService.new.call(Fabricate(:account), first_status)
+      FollowService.new.call(Fabricate(:account), user.account)
+    end
+
+    it_behaves_like 'forbidden for wrong scope', 'write write:notifications'
+
+    context 'with no options' do
+      it 'returns expected notifications count' do
+        subject
+
+        expect(response).to have_http_status(200)
+        expect(response.parsed_body[:count]).to eq 4
+      end
+    end
+
+    context 'with grouped_types parameter' do
+      let(:params) { { grouped_types: %w(reblog) } }
+
+      it 'returns expected notifications count' do
+        subject
+
+        expect(response).to have_http_status(200)
+        expect(response.parsed_body[:count]).to eq 5
+      end
+    end
+
+    context 'with a read marker' do
+      before do
+        id = user.account.notifications.browserable.order(id: :desc).offset(2).first.id
+        user.markers.create!(timeline: 'notifications', last_read_id: id)
+      end
+
+      it 'returns expected notifications count' do
+        subject
+
+        expect(response).to have_http_status(200)
+        expect(response.parsed_body[:count]).to eq 2
+      end
+    end
+
+    context 'with exclude_types param' do
+      let(:params) { { exclude_types: %w(mention) } }
+
+      it 'returns expected notifications count' do
+        subject
+
+        expect(response).to have_http_status(200)
+        expect(response.parsed_body[:count]).to eq 3
+      end
+    end
+
+    context 'with a user-provided limit' do
+      let(:params) { { limit: 2 } }
+
+      it 'returns a capped value' do
+        subject
+
+        expect(response).to have_http_status(200)
+        expect(response.parsed_body[:count]).to eq 2
+      end
+    end
+
+    context 'when there are more notifications than the limit' do
+      before do
+        stub_const('Api::V2::NotificationsController::DEFAULT_NOTIFICATIONS_COUNT_LIMIT', 2)
+      end
+
+      it 'returns a capped value' do
+        subject
+
+        expect(response).to have_http_status(200)
+        expect(response.parsed_body[:count]).to eq Api::V2::NotificationsController::DEFAULT_NOTIFICATIONS_COUNT_LIMIT
+      end
+    end
+  end
+
+  describe 'GET /api/v2/notifications', :inline_jobs do
+    subject do
+      get '/api/v2/notifications', headers: headers, params: params
+    end
+
+    let(:bob)    { Fabricate(:user) }
+    let(:tom)    { Fabricate(:user) }
+    let(:params) { {} }
+
+    before do
+      first_status = PostStatusService.new.call(user.account, text: 'Test')
+      ReblogService.new.call(bob.account, first_status)
+      PostStatusService.new.call(bob.account, text: 'Hello @alice')
+      FavouriteService.new.call(bob.account, first_status)
+      FavouriteService.new.call(tom.account, first_status)
+      FollowService.new.call(bob.account, user.account)
+    end
+
+    it_behaves_like 'forbidden for wrong scope', 'write write:notifications'
+
+    context 'when there are no notifications' do
+      before do
+        user.account.notifications.destroy_all
+      end
+
+      it 'returns 0 notifications' do
+        subject
+
+        expect(response).to have_http_status(200)
+        expect(response.parsed_body[:notification_groups]).to eq []
+      end
+    end
+
+    context 'with no options' do
+      it 'returns expected notification types', :aggregate_failures do
+        subject
+
+        expect(response).to have_http_status(200)
+        expect(body_json_types).to include('reblog', 'mention', 'favourite', 'follow')
+      end
+    end
+
+    context 'with grouped_types param' do
+      let(:params) { { grouped_types: %w(reblog) } }
+
+      it 'returns everything, but does not group favourites' do
+        subject
+
+        expect(response).to have_http_status(200)
+        expect(response.parsed_body[:notification_groups]).to contain_exactly(
+          a_hash_including(
+            type: 'reblog',
+            sample_account_ids: [bob.account_id.to_s]
+          ),
+          a_hash_including(
+            type: 'mention',
+            sample_account_ids: [bob.account_id.to_s]
+          ),
+          a_hash_including(
+            type: 'favourite',
+            sample_account_ids: [bob.account_id.to_s]
+          ),
+          a_hash_including(
+            type: 'favourite',
+            sample_account_ids: [tom.account_id.to_s]
+          ),
+          a_hash_including(
+            type: 'follow',
+            sample_account_ids: [bob.account_id.to_s]
+          )
+        )
+      end
+    end
+
+    context 'with exclude_types param' do
+      let(:params) { { exclude_types: %w(mention) } }
+
+      it 'returns everything but excluded type', :aggregate_failures do
+        subject
+
+        expect(response).to have_http_status(200)
+        expect(response.parsed_body.size).to_not eq 0
+        expect(body_json_types.uniq).to_not include 'mention'
+      end
+    end
+
+    context 'with types param' do
+      let(:params) { { types: %w(mention) } }
+
+      it 'returns only requested type', :aggregate_failures do
+        subject
+
+        expect(response).to have_http_status(200)
+        expect(body_json_types.uniq).to eq ['mention']
+        expect(response.parsed_body.dig(:notification_groups, 0, :page_min_id)).to_not be_nil
+      end
+    end
+
+    context 'with limit param' do
+      let(:params) { { limit: 3 } }
+      let(:notifications) { user.account.notifications.reorder(id: :desc) }
+
+      it 'returns the requested number of notifications paginated', :aggregate_failures do
+        subject
+
+        expect(response.parsed_body[:notification_groups].size)
+          .to eq(params[:limit])
+
+        expect(response)
+          .to include_pagination_headers(
+            prev: api_v2_notifications_url(limit: params[:limit], min_id: notifications.first.id),
+            # TODO: one downside of the current approach is that we return the first ID matching the group,
+            # not the last that has been skipped, so pagination is very likely to give overlap
+            next: api_v2_notifications_url(limit: params[:limit], max_id: notifications[3].id)
+          )
+      end
+    end
+
+    context 'with since_id param' do
+      let(:params) { { since_id: notifications[2].id } }
+      let(:notifications) { user.account.notifications.reorder(id: :desc) }
+
+      it 'returns the requested number of notifications paginated', :aggregate_failures do
+        subject
+
+        expect(response.parsed_body[:notification_groups].size)
+          .to eq(2)
+
+        expect(response)
+          .to include_pagination_headers(
+            prev: api_v2_notifications_url(limit: params[:limit], min_id: notifications.first.id),
+            # TODO: one downside of the current approach is that we return the first ID matching the group,
+            # not the last that has been skipped, so pagination is very likely to give overlap
+            next: api_v2_notifications_url(limit: params[:limit], max_id: notifications[1].id)
+          )
+      end
+    end
+
+    context 'when requesting stripped-down accounts' do
+      let(:params) { { expand_accounts: 'partial_avatars' } }
+
+      let(:recent_account) { Fabricate(:account) }
+
+      before do
+        FavouriteService.new.call(recent_account, user.account.statuses.first)
+      end
+
+      it 'returns an account in "partial_accounts", with the expected keys', :aggregate_failures do
+        subject
+
+        expect(response).to have_http_status(200)
+        expect(response.parsed_body[:partial_accounts].size).to be > 0
+        expect(response.parsed_body[:partial_accounts][0].keys.map(&:to_sym)).to contain_exactly(:acct, :avatar, :avatar_static, :bot, :id, :locked, :url)
+        expect(response.parsed_body[:partial_accounts].pluck(:id)).to_not include(recent_account.id.to_s)
+        expect(response.parsed_body[:accounts].pluck(:id)).to include(recent_account.id.to_s)
+      end
+    end
+
+    context 'when passing an invalid value for "expand_accounts"' do
+      let(:params) { { expand_accounts: 'unknown_foobar' } }
+
+      it 'returns http bad request' do
+        subject
+
+        expect(response).to have_http_status(400)
+      end
+    end
+
+    def body_json_types
+      response.parsed_body[:notification_groups].pluck(:type)
+    end
+  end
+
+  describe 'GET /api/v2/notifications/:id' do
+    subject do
+      get "/api/v2/notifications/#{notification.group_key}", headers: headers
+    end
+
+    let(:notification) { Fabricate(:notification, account: user.account, group_key: 'foobar') }
+
+    it_behaves_like 'forbidden for wrong scope', 'write write:notifications'
+
+    it 'returns http success' do
+      subject
+
+      expect(response).to have_http_status(200)
+    end
+
+    context 'when notification belongs to someone else' do
+      let(:notification) { Fabricate(:notification, group_key: 'foobar') }
+
+      it 'returns http not found' do
+        subject
+
+        expect(response).to have_http_status(404)
+      end
+    end
+  end
+
+  describe 'POST /api/v2/notifications/:id/dismiss' do
+    subject do
+      post "/api/v2/notifications/#{notification.group_key}/dismiss", headers: headers
+    end
+
+    let!(:notification) { Fabricate(:notification, account: user.account, group_key: 'foobar') }
+
+    it_behaves_like 'forbidden for wrong scope', 'read read:notifications'
+
+    it 'destroys the notification' do
+      subject
+
+      expect(response).to have_http_status(200)
+      expect { notification.reload }.to raise_error(ActiveRecord::RecordNotFound)
+    end
+
+    context 'when notification belongs to someone else' do
+      let(:notification) { Fabricate(:notification) }
+
+      it 'returns http not found' do
+        subject
+
+        expect(response).to have_http_status(404)
+      end
+    end
+  end
+
+  describe 'POST /api/v2/notifications/clear' do
+    subject do
+      post '/api/v2/notifications/clear', headers: headers
+    end
+
+    before do
+      Fabricate(:notification, account: user.account)
+    end
+
+    it_behaves_like 'forbidden for wrong scope', 'read read:notifications'
+
+    it 'clears notifications for the account' do
+      subject
+
+      expect(user.account.reload.notifications).to be_empty
+      expect(response).to have_http_status(200)
+    end
+  end
+end
diff --git a/spec/requests/api/v2_alpha/notifications_spec.rb b/spec/requests/api/v2_alpha/notifications_spec.rb
index b7821de561f9ebaa54ea10b185bd7939912e5ec5..6d7df45b6563ffcf6ae47716812e243486ff0cbc 100644
--- a/spec/requests/api/v2_alpha/notifications_spec.rb
+++ b/spec/requests/api/v2_alpha/notifications_spec.rb
@@ -1,5 +1,7 @@
 # frozen_string_literal: true
 
+# TODO: remove this before 4.3.0-rc1
+
 require 'rails_helper'
 
 RSpec.describe 'Notifications' do
@@ -84,14 +86,14 @@ RSpec.describe 'Notifications' do
 
     context 'when there are more notifications than the limit' do
       before do
-        stub_const('Api::V2Alpha::NotificationsController::DEFAULT_NOTIFICATIONS_COUNT_LIMIT', 2)
+        stub_const('Api::V2::NotificationsController::DEFAULT_NOTIFICATIONS_COUNT_LIMIT', 2)
       end
 
       it 'returns a capped value' do
         subject
 
         expect(response).to have_http_status(200)
-        expect(response.parsed_body[:count]).to eq Api::V2Alpha::NotificationsController::DEFAULT_NOTIFICATIONS_COUNT_LIMIT
+        expect(response.parsed_body[:count]).to eq Api::V2::NotificationsController::DEFAULT_NOTIFICATIONS_COUNT_LIMIT
       end
     end
   end
@@ -206,10 +208,10 @@ RSpec.describe 'Notifications' do
 
         expect(response)
           .to include_pagination_headers(
-            prev: api_v2_alpha_notifications_url(limit: params[:limit], min_id: notifications.first.id),
+            prev: api_v2_notifications_url(limit: params[:limit], min_id: notifications.first.id),
             # TODO: one downside of the current approach is that we return the first ID matching the group,
             # not the last that has been skipped, so pagination is very likely to give overlap
-            next: api_v2_alpha_notifications_url(limit: params[:limit], max_id: notifications[3].id)
+            next: api_v2_notifications_url(limit: params[:limit], max_id: notifications[3].id)
           )
       end
     end
@@ -226,10 +228,10 @@ RSpec.describe 'Notifications' do
 
         expect(response)
           .to include_pagination_headers(
-            prev: api_v2_alpha_notifications_url(limit: params[:limit], min_id: notifications.first.id),
+            prev: api_v2_notifications_url(limit: params[:limit], min_id: notifications.first.id),
             # TODO: one downside of the current approach is that we return the first ID matching the group,
             # not the last that has been skipped, so pagination is very likely to give overlap
-            next: api_v2_alpha_notifications_url(limit: params[:limit], max_id: notifications[1].id)
+            next: api_v2_notifications_url(limit: params[:limit], max_id: notifications[1].id)
           )
       end
     end