diff --git a/config/db/migrate/20260219103153_create_extension_device.rb b/config/db/migrate/20260219103153_create_extension_device.rb
new file mode 100644
index 00000000..d5e1de9b
--- /dev/null
+++ b/config/db/migrate/20260219103153_create_extension_device.rb
@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+
+ROM::SQL.migration do
+  change do
+    create_table :extension_device do
+      primary_key :id
+
+      foreign_key :extension_id, :extension, null: false, on_delete: :cascade, on_update: :cascade
+      foreign_key :device_id, :device, null: false, on_delete: :cascade, on_update: :cascade
+
+      column :created_at, :timestamp, null: false, default: Sequel::CURRENT_TIMESTAMP
+      column :updated_at, :timestamp, null: false, default: Sequel::CURRENT_TIMESTAMP
+    end
+
+    add_index :extension_device, %i[extension_id device_id], unique: true
+  end
+end
diff --git a/config/db/structure.sql b/config/db/structure.sql
index eb032022..72d92b5f 100644
--- a/config/db/structure.sql
+++ b/config/db/structure.sql
@@ -378,6 +378,33 @@ CREATE TABLE public.extension (
 );
 
 
+--
+-- Name: extension_device; Type: TABLE; Schema: public; Owner: -
+--
+
+CREATE TABLE public.extension_device (
+    id integer NOT NULL,
+    extension_id integer NOT NULL,
+    device_id integer NOT NULL,
+    created_at timestamp without time zone DEFAULT CURRENT_TIMESTAMP NOT NULL,
+    updated_at timestamp without time zone DEFAULT CURRENT_TIMESTAMP NOT NULL
+);
+
+
+--
+-- Name: extension_device_id_seq; Type: SEQUENCE; Schema: public; Owner: -
+--
+
+ALTER TABLE public.extension_device ALTER COLUMN id ADD GENERATED BY DEFAULT AS IDENTITY (
+    SEQUENCE NAME public.extension_device_id_seq
+    START WITH 1
+    INCREMENT BY 1
+    NO MINVALUE
+    NO MAXVALUE
+    CACHE 1
+);
+
+
 --
 -- Name: extension_id_seq; Type: SEQUENCE; Schema: public; Owner: -
 --
@@ -806,6 +833,14 @@ ALTER TABLE ONLY public.device
     ADD CONSTRAINT devices_pkey PRIMARY KEY (id);
 
 
+--
+-- Name: extension_device extension_device_pkey; Type: CONSTRAINT; Schema: public; Owner: -
+--
+
+ALTER TABLE ONLY public.extension_device
+    ADD CONSTRAINT extension_device_pkey PRIMARY KEY (id);
+
+
 --
 -- Name: extension extension_label_key; Type: CONSTRAINT; Schema: public; Owner: -
 --
@@ -1076,6 +1111,13 @@ CREATE INDEX device_sensor_kind_index ON public.device_sensor USING btree (kind)
 CREATE INDEX device_sensor_source_index ON public.device_sensor USING btree (source);
 
 
+--
+-- Name: extension_device_extension_id_device_id_index; Type: INDEX; Schema: public; Owner: -
+--
+
+CREATE UNIQUE INDEX extension_device_extension_id_device_id_index ON public.extension_device USING btree (extension_id, device_id);
+
+
 --
 -- Name: extension_model_extension_id_model_id_index; Type: INDEX; Schema: public; Owner: -
 --
@@ -1241,6 +1283,22 @@ ALTER TABLE ONLY public.device
     ADD CONSTRAINT devices_playlist_id_fkey FOREIGN KEY (playlist_id) REFERENCES public.playlist(id) ON UPDATE CASCADE ON DELETE SET NULL;
 
 
+--
+-- Name: extension_device extension_device_device_id_fkey; Type: FK CONSTRAINT; Schema: public; Owner: -
+--
+
+ALTER TABLE ONLY public.extension_device
+    ADD CONSTRAINT extension_device_device_id_fkey FOREIGN KEY (device_id) REFERENCES public.device(id) ON UPDATE CASCADE ON DELETE CASCADE;
+
+
+--
+-- Name: extension_device extension_device_extension_id_fkey; Type: FK CONSTRAINT; Schema: public; Owner: -
+--
+
+ALTER TABLE ONLY public.extension_device
+    ADD CONSTRAINT extension_device_extension_id_fkey FOREIGN KEY (extension_id) REFERENCES public.extension(id) ON UPDATE CASCADE ON DELETE CASCADE;
+
+
 --
 -- Name: extension_model extension_model_extension_id_fkey; Type: FK CONSTRAINT; Schema: public; Owner: -
 --
@@ -1411,4 +1469,5 @@ INSERT INTO schema_migrations (filename) VALUES
 ('20260106144016_alter_firmware_kind.rb'),
 ('20260126141642_alter_device_table_model_id_as_non_null.rb'),
 ('20260209163817_add_model_palette_ids_and_css_columns.rb'),
-('20260217081447_create_device_sensor.rb');
+('20260217081447_create_device_sensor.rb'),
+('20260219103153_create_extension_device.rb');