diff --git a/spec/integration/status_transitions_spec.rb b/spec/integration/status_transitions_spec.rb
new file mode 100644
index 0000000..9b0fa22
--- /dev/null
+++ b/spec/integration/status_transitions_spec.rb
@@ -0,0 +1,177 @@
+# frozen_string_literal: true
+
+RSpec.describe "Support-ticket status transitions" do
+  before { enable_current_plugin }
+
+  fab!(:admin)
+  fab!(:customer) { Fabricate(:user) }
+  fab!(:category)
+
+  def create_ticket(user)
+    PostCreator.create!(
+      user,
+      title: "A support ticket title for the spec",
+      raw: "Initial ticket body, comfortably long enough.",
+      category: category.id,
+      skip_validations: true,
+    ).topic
+  end
+
+  def reply!(user, topic, type: Post.types[:regular])
+    PostCreator.create!(
+      user,
+      topic_id: topic.id,
+      raw: "A reply body, comfortably long enough.",
+      post_type: type,
+      skip_validations: true,
+    )
+  end
+
+  def set_status!(topic, status, extra = {})
+    { status: status }.merge(extra).each { |k, v| topic.custom_fields[k] = v }
+    topic.save_custom_fields
+  end
+
+  def rows(topic)
+    CommunityCustomFields::TopicStatusChange.where(topic_id: topic.id).order(:id)
+  end
+
+  describe "topic_created" do
+    it "seeds status=new for an admin-created topic and records no row" do
+      topic = create_ticket(admin)
+
+      expect(topic.reload.custom_fields["status"]).to eq("new")
+      expect(rows(topic)).to be_empty
+    end
+
+    it "sets waiting_* when a non-admin creates the topic" do
+      topic = create_ticket(customer)
+
+      expect(topic.reload.custom_fields["status"]).to eq("new")
+      expect(topic.custom_fields["waiting_id"].to_i).to eq(customer.id)
+      expect(topic.custom_fields["waiting_since"]).to be_present
+    end
+  end
+
+  describe "customer reply (non-admin)" do
+    it "reopens a snoozed topic to open and records a post_creation row" do
+      topic = create_ticket(admin)
+      set_status!(topic, "snoozed", assignee_id: customer.id)
+
+      post = reply!(customer, topic)
+
+      expect(topic.reload.custom_fields["status"]).to eq("open")
+      expect(rows(topic).last).to have_attributes(
+        from_status: "snoozed",
+        to_status: "open",
+        source: "post_creation",
+        post_id: post.id,
+        user_id: nil,
+        assignee_id: customer.id,
+      )
+    end
+
+    it "reopens a recently-closed assigned topic to open and reassigns" do
+      topic = create_ticket(admin)
+      set_status!(
+        topic,
+        "closed",
+        last_assigned_to_id: customer.id,
+        closed_at: Time.current.iso8601,
+      )
+
+      reply!(customer, topic)
+
+      topic.reload
+      expect(topic.custom_fields["status"]).to eq("open")
+      expect(topic.custom_fields["assignee_id"].to_i).to eq(customer.id)
+      expect(rows(topic).last.to_status).to eq("open")
+    end
+
+    it "reopens a closed topic with no last assignee to new" do
+      topic = create_ticket(admin)
+      set_status!(topic, "closed", closed_at: Time.current.iso8601)
+
+      reply!(customer, topic)
+
+      expect(topic.reload.custom_fields["status"]).to eq("new")
+      expect(rows(topic).last.to_status).to eq("new")
+    end
+
+    it "reopens a >1-month-closed topic to new despite a last assignee" do
+      topic = create_ticket(admin)
+      set_status!(
+        topic,
+        "closed",
+        last_assigned_to_id: customer.id,
+        closed_at: 2.months.ago.iso8601,
+      )
+
+      reply!(customer, topic)
+
+      expect(topic.reload.custom_fields["status"]).to eq("new")
+    end
+
+    it "sets waiting_* and records no row when the status does not change" do
+      topic = create_ticket(admin)
+      set_status!(topic, "open")
+
+      reply!(customer, topic)
+
+      topic.reload
+      expect(topic.custom_fields["status"]).to eq("open")
+      expect(topic.custom_fields["waiting_id"].to_i).to eq(customer.id)
+      expect(rows(topic)).to be_empty
+    end
+  end
+
+  describe "admin whisper (post_type 4)" do
+    before { SiteSetting.whispers_allowed_groups = Group::AUTO_GROUPS[:staff].to_s }
+
+    it "reopens a snoozed topic to open" do
+      topic = create_ticket(admin)
+      set_status!(topic, "snoozed")
+
+      reply!(admin, topic, type: Post.types[:whisper])
+
+      expect(topic.reload.custom_fields["status"]).to eq("open")
+      expect(rows(topic).last).to have_attributes(
+        from_status: "snoozed",
+        to_status: "open",
+        source: "post_creation",
+      )
+    end
+
+    it "reopens a closed assigned topic to open" do
+      topic = create_ticket(admin)
+      set_status!(topic, "closed", last_assigned_to_id: customer.id)
+
+      reply!(admin, topic, type: Post.types[:whisper])
+
+      expect(topic.reload.custom_fields["status"]).to eq("open")
+    end
+
+    it "reopens a closed topic with no last assignee to new" do
+      topic = create_ticket(admin)
+      set_status!(topic, "closed")
+
+      reply!(admin, topic, type: Post.types[:whisper])
+
+      expect(topic.reload.custom_fields["status"]).to eq("new")
+    end
+  end
+
+  describe "admin regular reply (post_type 1)" do
+    it "clears waiting_* and records no row" do
+      topic = create_ticket(admin)
+      set_status!(topic, "open", waiting_since: 1.hour.ago.iso8601, waiting_id: customer.id)
+
+      reply!(admin, topic)
+
+      topic.reload
+      expect(topic.custom_fields["status"]).to eq("open")
+      expect(topic.custom_fields["waiting_id"]).to be_blank
+      expect(rows(topic)).to be_empty
+    end
+  end
+end
diff --git a/spec/requests/community_custom_fields/custom_fields_controller_spec.rb b/spec/requests/community_custom_fields/custom_fields_controller_spec.rb
new file mode 100644
index 0000000..91b3c97
--- /dev/null
+++ b/spec/requests/community_custom_fields/custom_fields_controller_spec.rb
@@ -0,0 +1,117 @@
+# frozen_string_literal: true
+
+RSpec.describe "CommunityCustomFields::CustomFieldsController", type: :request do
+  before { enable_current_plugin }
+
+  fab!(:admin)
+  fab!(:assignee) { Fabricate(:user) }
+  fab!(:topic)
+
+  STATUSES = %w[new open snoozed closed]
+
+  def set_status(topic, status, extra = {})
+    { status: status }.merge(extra).each { |k, v| topic.custom_fields[k] = v }
+    topic.save_custom_fields
+  end
+
+  def put_fields(topic, fields)
+    put "/admin/plugins/community-custom-fields/#{topic.id}.json", params: { custom_field: fields }
+  end
+
+  def rows(topic)
+    CommunityCustomFields::TopicStatusChange.where(topic_id: topic.id).order(:id)
+  end
+
+  context "as an admin" do
+    before { sign_in(admin) }
+
+    STATUSES.each do |from|
+      STATUSES.each do |to|
+        next if from == to
+
+        it "records an api_update row for #{from} -> #{to}" do
+          set_status(topic, from)
+          put_fields(topic, status: to)
+
+          expect(response.status).to eq(200)
+          expect(topic.reload.custom_fields["status"]).to eq(to)
+          expect(rows(topic).count).to eq(1)
+          expect(rows(topic).last).to have_attributes(
+            from_status: from,
+            to_status: to,
+            source: "api_update",
+            user_id: admin.id,
+            post_id: nil,
+          )
+          expect(rows(topic).last.duration).to be >= 0
+        end
+      end
+    end
+
+    it "records a from_status=null row when the topic had no prior status" do
+      expect(topic.custom_fields["status"]).to be_nil
+
+      put_fields(topic, status: "open")
+
+      expect(response.status).to eq(200)
+      expect(rows(topic).count).to eq(1)
+      expect(rows(topic).last).to have_attributes(from_status: nil, to_status: "open")
+      expect(rows(topic).last.duration).to be >= 0
+    end
+
+    it "rejects an invalid status with 422 and records nothing" do
+      set_status(topic, "open")
+
+      put_fields(topic, status: "bogus")
+
+      expect(response.status).to eq(422)
+      expect(topic.reload.custom_fields["status"]).to eq("open")
+      expect(rows(topic)).to be_empty
+    end
+
+    it "records no row when the status does not change" do
+      set_status(topic, "open")
+
+      put_fields(topic, priority: "high")
+
+      expect(response.status).to eq(200)
+      expect(rows(topic)).to be_empty
+    end
+
+    it "attributes the row to the assignee before the change" do
+      set_status(topic, "open", assignee_id: assignee.id)
+
+      put_fields(topic, status: "closed", assignee_id: "")
+
+      expect(response.status).to eq(200)
+      expect(rows(topic).last).to have_attributes(to_status: "closed", assignee_id: assignee.id)
+    end
+
+    it "measures duration from the previous recorded change" do
+      freeze_time
+      set_status(topic, "open")
+      CommunityCustomFields::TopicStatusChange.create!(
+        topic_id: topic.id,
+        from_status: "new",
+        to_status: "open",
+        source: "api_update",
+        duration: 0,
+        created_at: 1.hour.ago,
+      )
+
+      put_fields(topic, status: "closed")
+
+      expect(response.status).to eq(200)
+      expect(rows(topic).last.duration).to eq(1.hour.to_i)
+    end
+  end
+
+  it "forbids non-admins and records nothing" do
+    sign_in(Fabricate(:user))
+
+    put_fields(topic, status: "open")
+
+    expect(response.status).to eq(403)
+    expect(rows(topic)).to be_empty
+  end
+end