diff --git a/config/initializers/acts_as_taggable_on.rb b/config/initializers/acts_as_taggable_on.rb
index 45b6e706c..719f1271f 100644
--- a/config/initializers/acts_as_taggable_on.rb
+++ b/config/initializers/acts_as_taggable_on.rb
@@ -21,7 +21,7 @@ module ActsAsTaggableOn
   Tag.class_eval do
 
     include Graphqlable
-    
+
     def increment_custom_counter_for(taggable_type)
       Tag.increment_counter(custom_counter_field_name_for(taggable_type), id)
     end
@@ -45,7 +45,20 @@ module ActsAsTaggableOn
     end
 
     def self.public_for_api
-      where("kind IS NULL OR kind = 'category'")
+      find_by_sql(%|
+        SELECT *
+        FROM tags
+        WHERE (tags.kind IS NULL OR tags.kind = 'category') AND tags.id IN (
+          SELECT tag_id
+          FROM (
+            SELECT COUNT(taggings.id) AS taggings_count, tag_id
+            FROM ((taggings FULL OUTER JOIN proposals ON taggable_type = 'Proposal' AND taggable_id = proposals.id) FULL OUTER JOIN debates ON taggable_type = 'Debate' AND taggable_id = debates.id)
+            WHERE (taggable_type = 'Proposal' AND proposals.hidden_at IS NULL) OR (taggable_type = 'Debate' AND debates.hidden_at IS NULL)
+            GROUP BY tag_id
+          ) AS tag_taggings_count_relation
+          WHERE taggings_count > 0
+        )
+      |)
     end
 
     private
diff --git a/spec/lib/acts_as_taggable_on_spec.rb b/spec/lib/acts_as_taggable_on_spec.rb
index 59a469f88..d261bbad2 100644
--- a/spec/lib/acts_as_taggable_on_spec.rb
+++ b/spec/lib/acts_as_taggable_on_spec.rb
@@ -66,23 +66,72 @@ describe 'ActsAsTaggableOn' do
     end
 
     describe "public_for_api scope" do
-      it "returns tags whose kind is NULL" do
+
+      it "returns tags whose kind is NULL and have at least one tagging whose taggable is not hidden" do
         tag = create(:tag, kind: nil)
+        proposal = create(:proposal)
+        proposal.tag_list.add(tag)
+        proposal.save
 
         expect(ActsAsTaggableOn::Tag.public_for_api).to include(tag)
       end
 
-      it "returns tags whose kind is 'category'" do
+      it "returns tags whose kind is 'category' and have at least one tagging whose taggable is not hidden" do
         tag = create(:tag, kind: 'category')
+        proposal = create(:proposal)
+        proposal.tag_list.add(tag)
+        proposal.save
 
         expect(ActsAsTaggableOn::Tag.public_for_api).to include(tag)
       end
 
       it "blocks other kinds of tags" do
         tag = create(:tag, kind: 'foo')
+        proposal = create(:proposal)
+        proposal.tag_list.add(tag)
+        proposal.save
 
         expect(ActsAsTaggableOn::Tag.public_for_api).not_to include(tag)
       end
+
+      it "blocks tags that don't have at least one tagged element" do
+        tag = create(:tag)
+
+        expect(ActsAsTaggableOn::Tag.public_for_api).to_not include(tag)
+      end
+
+      it 'only permits tags on proposals or debates' do
+        tag_1 = create(:tag)
+        tag_2 = create(:tag)
+        tag_3 = create(:tag)
+
+        proposal = create(:proposal)
+        spending_proposal = create(:spending_proposal)
+        debate = create(:debate)
+
+        proposal.tag_list.add(tag_1)
+        spending_proposal.tag_list.add(tag_2)
+        debate.tag_list.add(tag_3)
+
+        proposal.save
+        spending_proposal.save
+        debate.save
+
+        expect(ActsAsTaggableOn::Tag.public_for_api).to match_array([tag_1, tag_3])
+      end
+
+      it 'blocks tags after its taggings became hidden' do
+        tag = create(:tag)
+        proposal = create(:proposal)
+        proposal.tag_list.add(tag)
+        proposal.save
+
+        expect(ActsAsTaggableOn::Tag.public_for_api).to include(tag)
+
+        proposal.delete
+
+        expect(ActsAsTaggableOn::Tag.public_for_api).to be_empty
+      end
     end
   end
 
diff --git a/spec/models/comment_spec.rb b/spec/models/comment_spec.rb
index db68a9e4e..993710c13 100644
--- a/spec/models/comment_spec.rb
+++ b/spec/models/comment_spec.rb
@@ -134,7 +134,7 @@ describe Comment do
     end
   end
 
-  describe "public_for_api" do
+  describe "public_for_api scope" do
     it "returns comments" do
       comment = create(:comment)
 
@@ -174,5 +174,12 @@ describe Comment do
 
       expect(Comment.public_for_api).not_to include(comment)
     end
+
+    it 'does not return comments on budget investments' do
+      budget_investment = create(:budget_investment)
+      comment = create(:comment, commentable: budget_investment)
+
+      expect(Comment.public_for_api).not_to include(comment)
+    end
   end
 end
diff --git a/spec/models/debate_spec.rb b/spec/models/debate_spec.rb
index 5272b6e7a..bae8a5f16 100644
--- a/spec/models/debate_spec.rb
+++ b/spec/models/debate_spec.rb
@@ -700,4 +700,16 @@ describe Debate do
     end
   end
 
+  describe 'public_for_api scope' do
+    it 'returns debates' do
+      debate = create(:debate)
+      expect(Debate.public_for_api).to include(debate)
+    end
+
+    it 'does not return hidden debates' do
+      debate = create(:debate, :hidden)
+      expect(Debate.public_for_api).to_not include(debate)
+    end
+  end
+
 end
diff --git a/spec/models/proposal_spec.rb b/spec/models/proposal_spec.rb
index 7c8d3fb41..b2bb63140 100644
--- a/spec/models/proposal_spec.rb
+++ b/spec/models/proposal_spec.rb
@@ -842,4 +842,16 @@ describe Proposal do
     end
   end
 
+  describe 'public_for_api scope' do
+    it 'returns proposals' do
+      proposal = create(:proposal)
+      expect(Proposal.public_for_api).to include(proposal)
+    end
+
+    it 'does not return hidden proposals' do
+      proposal = create(:proposal, :hidden)
+      expect(Proposal.public_for_api).to_not include(proposal)
+    end
+  end
+
 end