diff --git a/app/models/rule.rb b/app/models/rule.rb
index 275c9ba..f8c5243 100644
--- a/app/models/rule.rb
+++ b/app/models/rule.rb
@@ -37,7 +37,8 @@ class DiscourseChatIntegration::Rule < DiscourseChatIntegration::PluginModel
       WHEN value::json->>'filter' = 'mute' THEN 1
       WHEN value::json->>'filter' = 'thread' THEN 2
       WHEN value::json->>'filter' = 'watch' THEN 3
-      WHEN value::json->>'filter' = 'follow' THEN 4
+      WHEN value::json->>'filter' = 'tag_added' THEN 4
+      WHEN value::json->>'filter' = 'follow' THEN 5
      END
     ",
           )
@@ -47,7 +48,7 @@ class DiscourseChatIntegration::Rule < DiscourseChatIntegration::PluginModel
 
   validates :filter,
             inclusion: {
-              in: %w[thread watch follow mute],
+              in: %w[thread watch follow tag_added mute],
               message: "%{value} is not a valid filter",
             }
 
diff --git a/app/services/manager.rb b/app/services/manager.rb
index a0c4e0c..e8c370f 100644
--- a/app/services/manager.rb
+++ b/app/services/manager.rb
@@ -12,8 +12,14 @@ module DiscourseChatIntegration
       # Abort if the chat_user doesn't have permission to see the post
       return if !guardian.can_see?(post)
 
-      # Abort if the post is blank, or is non-regular (e.g. a "topic closed" notification)
-      return if post.blank? || post.post_type != Post.types[:regular]
+      # Abort if the post is blank
+      return if post.blank?
+
+      # Abort if post is not either regular, or a 'tags_changed' small action
+      if (post.post_type != Post.types[:regular]) &&
+           !(post.post_type == Post.types[:small_action] && post.action_code == "tags_changed")
+        return
+      end
 
       topic = post.topic
       return if topic.blank?
@@ -46,6 +52,33 @@ module DiscourseChatIntegration
         end
       end
 
+      if post.action_code == "tags_changed"
+        # Post is a small_action post regarding tags changing for the topic. Check if any tags were _added_
+        # and if so, corresponding rules with `filter: tag_added`
+        tags_added = post.custom_fields["tags_added"]
+        tags_added = [tags_added].compact if !tags_added.is_a?(Array)
+        return if tags_added.blank?
+
+        tags_removed = post.custom_fields["tags_removed"]
+        tags_removed = [tags_removed].compact if !tags_removed.is_a?(Array)
+
+        unchanged_tags = topic.tags.map(&:name) - tags_added - tags_removed
+
+        matching_rules =
+          matching_rules.select do |rule|
+            # Only rules that match this post, are ones where the filter is "tag_added"
+            next false if rule.filter != "tag_added"
+            next true if rule.tags.blank?
+
+            # Skip if the topic already has one of the tags in the rule, applied
+            next false if unchanged_tags.any? && (unchanged_tags & rule.tags).any?
+
+            # We don't need to do any additional filtering here because topics are filtered
+            # by tag later
+            true
+          end
+      end
+
       # If tagging is enabled, thow away rules that don't apply to this topic
       if SiteSetting.tagging_enabled
         topic_tags = topic.tags.present? ? topic.tags.pluck(:name) : []
@@ -59,7 +92,7 @@ module DiscourseChatIntegration
 
       # Sort by order of precedence
       t_prec = { "group_message" => 0, "group_mention" => 1, "normal" => 2 } # Group things win
-      f_prec = { "mute" => 0, "thread" => 1, "watch" => 2, "follow" => 3 } #(mute always wins; thread beats watch beats follow)
+      f_prec = { "mute" => 0, "thread" => 1, "watch" => 2, "follow" => 3, "tag_added" => 4 } #(mute always wins; thread beats watch beats follow)
       sort_func =
         proc { |a, b| [t_prec[a.type], f_prec[a.filter]] <=> [t_prec[b.type], f_prec[b.filter]] }
       matching_rules = matching_rules.sort(&sort_func)
diff --git a/assets/javascripts/admin/models/rule.js b/assets/javascripts/admin/models/rule.js
index 67a3649..c37dff6 100644
--- a/assets/javascripts/admin/models/rule.js
+++ b/assets/javascripts/admin/models/rule.js
@@ -46,6 +46,11 @@ export default class Rule extends RestModel {
         name: I18n.t("chat_integration.filter.follow"),
         icon: "circle",
       },
+      {
+        id: "tag_added",
+        name: I18n.t("chat_integration.filter.tag_added"),
+        icon: "tag",
+      },
       {
         id: "mute",
         name: I18n.t("chat_integration.filter.mute"),
diff --git a/config/locales/client.en.yml b/config/locales/client.en.yml
index 7c3583d..18abb5d 100644
--- a/config/locales/client.en.yml
+++ b/config/locales/client.en.yml
@@ -36,6 +36,7 @@ en:
         mute: 'Mute'
         follow: 'First post only'
         watch: 'All posts and replies'
+        tag_added: 'Tag added to topic'
         thread: 'All posts with threaded replies'
       rule_table:
         filter: "Filter"
diff --git a/spec/services/manager_spec.rb b/spec/services/manager_spec.rb
index c749cd9..f0823bd 100644
--- a/spec/services/manager_spec.rb
+++ b/spec/services/manager_spec.rb
@@ -345,6 +345,69 @@ RSpec.describe DiscourseChatIntegration::Manager do
 
         expect(provider.sent_to_channel_ids).to contain_exactly(chan1.id)
       end
+
+      describe "with create_small_action_post_for_tag_changes enabled" do
+        fab!(:admin) { Fabricate(:admin) }
+        fab!(:additional_tag) { Fabricate(:tag) }
+
+        before { SiteSetting.create_post_for_category_and_tag_changes = true }
+
+        def set_new_tags_and_return_small_action_post(tags)
+          PostRevisor.new(tagged_first_post).revise!(admin, tags: tags)
+
+          tagged_topic.ordered_posts.last
+        end
+
+        it "should notify when rule is set up for tag additions for a category with no tag filter" do
+          post = set_new_tags_and_return_small_action_post([tag.name, additional_tag.name])
+
+          DiscourseChatIntegration::Rule.create!(
+            channel: chan1,
+            filter: "tag_added",
+            category_id: category.id,
+          )
+
+          manager.trigger_notifications(post.id)
+          expect(provider.sent_to_channel_ids).to contain_exactly(chan1.id)
+        end
+
+        it "notifies when topic has a tag added that matches the rule" do
+          post = set_new_tags_and_return_small_action_post([tag.name, additional_tag.name])
+
+          DiscourseChatIntegration::Rule.create!(
+            channel: chan1,
+            filter: "tag_added",
+            category_id: category.id,
+            tags: [additional_tag.name],
+          )
+
+          manager.trigger_notifications(post.id)
+          expect(provider.sent_to_channel_ids).to contain_exactly(chan1.id)
+        end
+
+        it "doesn't notify when topic has an unchanged tag present in the rule, even if a new tag is added" do
+          post = set_new_tags_and_return_small_action_post([tag.name, additional_tag.name])
+
+          DiscourseChatIntegration::Rule.create!(
+            channel: chan1,
+            filter: "tag_added",
+            category_id: category.id,
+            tags: [tag.name],
+          )
+
+          manager.trigger_notifications(post.id)
+          expect(provider.sent_to_channel_ids).to contain_exactly
+        end
+
+        it "doesn't notify for small action 'tags_changed' posts unless a matching rule exists" do
+          post = set_new_tags_and_return_small_action_post([additional_tag.name])
+
+          DiscourseChatIntegration::Rule.create!(channel: chan1, filter: "watch", category_id: nil) # Wildcard watch
+
+          manager.trigger_notifications(post.id)
+          expect(provider.sent_to_channel_ids).to contain_exactly
+        end
+      end
     end
   end
 end