diff --git a/package-lock.json b/package-lock.json
index 4566831..07fa605 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -9,6 +9,7 @@
       "version": "0.1.0",
       "dependencies": {
         "@hello-pangea/dnd": "^18.0.1",
+        "@radix-ui/react-collapsible": "^1.1.12",
         "@radix-ui/react-dialog": "^1.1.15",
         "@radix-ui/react-label": "^2.1.8",
         "@radix-ui/react-popover": "^1.1.15",
@@ -801,6 +802,36 @@
         }
       }
     },
+    "node_modules/@radix-ui/react-collapsible": {
+      "version": "1.1.12",
+      "resolved": "https://registry.npmjs.org/@radix-ui/react-collapsible/-/react-collapsible-1.1.12.tgz",
+      "integrity": "sha512-Uu+mSh4agx2ib1uIGPP4/CKNULyajb3p92LsVXmH2EHVMTfZWpll88XJ0j4W0z3f8NK1eYl1+Mf/szHPmcHzyA==",
+      "license": "MIT",
+      "dependencies": {
+        "@radix-ui/primitive": "1.1.3",
+        "@radix-ui/react-compose-refs": "1.1.2",
+        "@radix-ui/react-context": "1.1.2",
+        "@radix-ui/react-id": "1.1.1",
+        "@radix-ui/react-presence": "1.1.5",
+        "@radix-ui/react-primitive": "2.1.3",
+        "@radix-ui/react-use-controllable-state": "1.2.2",
+        "@radix-ui/react-use-layout-effect": "1.1.1"
+      },
+      "peerDependencies": {
+        "@types/react": "*",
+        "@types/react-dom": "*",
+        "react": "^16.8 || ^17.0 || ^18.0 || ^19.0 || ^19.0.0-rc",
+        "react-dom": "^16.8 || ^17.0 || ^18.0 || ^19.0 || ^19.0.0-rc"
+      },
+      "peerDependenciesMeta": {
+        "@types/react": {
+          "optional": true
+        },
+        "@types/react-dom": {
+          "optional": true
+        }
+      }
+    },
     "node_modules/@radix-ui/react-collection": {
       "version": "1.1.7",
       "resolved": "https://registry.npmjs.org/@radix-ui/react-collection/-/react-collection-1.1.7.tgz",
diff --git a/package.json b/package.json
index 96677dc..99aa8e8 100644
--- a/package.json
+++ b/package.json
@@ -9,6 +9,7 @@
   },
   "dependencies": {
     "@hello-pangea/dnd": "^18.0.1",
+    "@radix-ui/react-collapsible": "^1.1.12",
     "@radix-ui/react-dialog": "^1.1.15",
     "@radix-ui/react-label": "^2.1.8",
     "@radix-ui/react-popover": "^1.1.15",
diff --git a/src/app/workspace/page.tsx b/src/app/workspace/page.tsx
index a7eb37a..dfe152b 100644
--- a/src/app/workspace/page.tsx
+++ b/src/app/workspace/page.tsx
@@ -1,6 +1,6 @@
 "use client";
 
-import AppSidebar, { SidebarTrigger } from "@/components/AppSidebar";
+import AppSidebar, { SidebarTrigger } from "@/components/sidebar/AppSidebar";
 import BoardView from "@/components/view/board/BoardView";
 import TaskView from "@/components/view/TaskView";
 import { Task } from "@/lib/types";
diff --git a/src/components/AppSidebar.tsx b/src/components/sidebar/AppSidebar.tsx
similarity index 60%
rename from src/components/AppSidebar.tsx
rename to src/components/sidebar/AppSidebar.tsx
index a3d6e1a..fd75603 100644
--- a/src/components/AppSidebar.tsx
+++ b/src/components/sidebar/AppSidebar.tsx
@@ -1,13 +1,21 @@
-import { cn } from "@/lib/utils";
-import { Button } from "./ui/button";
 import {
   Sidebar,
   SidebarContent,
   SidebarFooter,
   SidebarHeader,
+  SidebarMenu,
   SidebarProvider,
   useSidebar,
-} from "./ui/sidebar";
+} from "@/components/ui/sidebar";
+import EntitySwitch, { Entity } from "./Entity";
+
+const workspaceEntities: Entity[] = [
+  {
+    name: "Project alpha",
+    kind: "group",
+    children: [{ name: "Tasks", kind: "todo" }],
+  },
+];
 
 export default function AppSidebar({
   children,
@@ -18,7 +26,13 @@ export default function AppSidebar({
     <SidebarProvider>
       <Sidebar>
         <SidebarHeader />
-        <SidebarContent></SidebarContent>
+        <SidebarContent>
+          <SidebarMenu>
+            {workspaceEntities.map((entity, i) => (
+              <EntitySwitch entity={entity} key={i} />
+            ))}
+          </SidebarMenu>
+        </SidebarContent>
         <SidebarFooter />
       </Sidebar>
       <main className="w-svw">{children}</main>
diff --git a/src/components/sidebar/Entity.tsx b/src/components/sidebar/Entity.tsx
new file mode 100644
index 0000000..70f05e6
--- /dev/null
+++ b/src/components/sidebar/Entity.tsx
@@ -0,0 +1,52 @@
+import { CollapsibleTrigger } from "@radix-ui/react-collapsible";
+import {
+  SidebarGroup,
+  SidebarGroupContent,
+  SidebarGroupLabel,
+  SidebarMenu,
+  SidebarMenuButton,
+  SidebarMenuItem,
+} from "../ui/sidebar";
+import { Collapsible, CollapsibleContent } from "../ui/collapsible";
+import { ChevronDown } from "lucide-react";
+
+export interface Entity {
+  name: string;
+  kind: "group" | "todo";
+  children?: Entity[];
+}
+
+export default function EntitySwitch({ entity }: { entity: Entity }) {
+  switch (entity.kind) {
+    case "group":
+      return (
+        <Collapsible defaultOpen className="group/collapsible">
+          <SidebarGroup>
+            <SidebarGroupLabel asChild>
+              <SidebarMenuButton asChild>
+                <CollapsibleTrigger>
+                  {entity.name}
+                  <ChevronDown className="ml-auto transition-transform group-data-[state=open]/collapsible:rotate-180" />
+                </CollapsibleTrigger>
+              </SidebarMenuButton>
+            </SidebarGroupLabel>
+            <CollapsibleContent>
+              <SidebarGroupContent>
+                <SidebarMenu>
+                  {entity.children?.map((entity, i) => (
+                    <EntitySwitch entity={entity} key={i} />
+                  ))}
+                </SidebarMenu>
+              </SidebarGroupContent>
+            </CollapsibleContent>
+          </SidebarGroup>
+        </Collapsible>
+      );
+    case "todo":
+      return (
+        <SidebarMenuItem>
+          <SidebarMenuButton>{entity.name}</SidebarMenuButton>
+        </SidebarMenuItem>
+      );
+  }
+}
diff --git a/src/components/ui/collapsible.tsx b/src/components/ui/collapsible.tsx
new file mode 100644
index 0000000..ae9fad0
--- /dev/null
+++ b/src/components/ui/collapsible.tsx
@@ -0,0 +1,33 @@
+"use client"
+
+import * as CollapsiblePrimitive from "@radix-ui/react-collapsible"
+
+function Collapsible({
+  ...props
+}: React.ComponentProps<typeof CollapsiblePrimitive.Root>) {
+  return <CollapsiblePrimitive.Root data-slot="collapsible" {...props} />
+}
+
+function CollapsibleTrigger({
+  ...props
+}: React.ComponentProps<typeof CollapsiblePrimitive.CollapsibleTrigger>) {
+  return (
+    <CollapsiblePrimitive.CollapsibleTrigger
+      data-slot="collapsible-trigger"
+      {...props}
+    />
+  )
+}
+
+function CollapsibleContent({
+  ...props
+}: React.ComponentProps<typeof CollapsiblePrimitive.CollapsibleContent>) {
+  return (
+    <CollapsiblePrimitive.CollapsibleContent
+      data-slot="collapsible-content"
+      {...props}
+    />
+  )
+}
+
+export { Collapsible, CollapsibleTrigger, CollapsibleContent }