diff --git a/packages/opencode/src/cli/cmd/tui/routes/session/index.tsx b/packages/opencode/src/cli/cmd/tui/routes/session/index.tsx
index 10e340d7f8f..fe84a830083 100644
--- a/packages/opencode/src/cli/cmd/tui/routes/session/index.tsx
+++ b/packages/opencode/src/cli/cmd/tui/routes/session/index.tsx
@@ -141,9 +141,12 @@ export function Session() {
   const [conceal, setConceal] = createSignal(true)
   const [showThinking, setShowThinking] = kv.signal("thinking_visibility", true)
   const [timestamps, setTimestamps] = kv.signal<"hide" | "show">("timestamps", "hide")
+  const [usernameVisible, setUsernameVisible] = kv.signal("username_visible", true)
   const [showDetails, setShowDetails] = kv.signal("tool_details_visibility", true)
   const [showAssistantMetadata, setShowAssistantMetadata] = kv.signal("assistant_metadata_visibility", true)
   const [showScrollbar, setShowScrollbar] = kv.signal("scrollbar_visible", false)
+  const [userMessageMarkdown, setUserMessageMarkdown] = kv.signal("user_message_markdown", true)
+  const [sidebarOverlayEnabled, setSidebarOverlayEnabled] = kv.signal("sidebar_overlay", true)
   const [diffWrapMode, setDiffWrapMode] = createSignal<"word" | "none">("word")
   const [animationsEnabled, setAnimationsEnabled] = kv.signal("animations_enabled", true)
 
@@ -155,7 +158,11 @@ export function Session() {
     return false
   })
   const showTimestamps = createMemo(() => timestamps() === "show")
-  const contentWidth = createMemo(() => dimensions().width - (sidebarVisible() ? 42 : 0) - 4)
+  const sidebarOverlay = createMemo(() => {
+    if (!sidebarOverlayEnabled()) return false
+    return sidebarVisible() && !wide()
+  })
+  const contentWidth = createMemo(() => dimensions().width - (sidebarVisible() && !sidebarOverlay() ? 42 : 0) - 4)
 
   const scrollAcceleration = createMemo(() => {
     const tui = sync.data.config.tui
@@ -463,6 +470,34 @@ export function Session() {
         dialog.clear()
       },
     },
+    {
+      title: sidebarOverlayEnabled() ? "Disable sidebar overlay" : "Enable sidebar overlay",
+      value: "sidebar_overlay",
+      keybind: "sidebar_overlay_toggle",
+      category: "System",
+      onSelect: (dialog) => {
+        setSidebarOverlayEnabled((prev) => {
+          const next = !prev
+          kv.set("sidebar_overlay", next)
+          return next
+        })
+        dialog.clear()
+      },
+    },
+    {
+      title: usernameVisible() ? "Hide username" : "Show username",
+      value: "session.username_visible.toggle",
+      keybind: "username_toggle",
+      category: "Session",
+      onSelect: (dialog) => {
+        setUsernameVisible((prev) => {
+          const next = !prev
+          kv.set("username_visible", next)
+          return next
+        })
+        dialog.clear()
+      },
+    },
     {
       title: "Toggle code concealment",
       value: "session.toggle.conceal",
diff --git a/packages/opencode/src/config/config.ts b/packages/opencode/src/config/config.ts
index ead3a0149b4..6b03f805dd1 100644
--- a/packages/opencode/src/config/config.ts
+++ b/packages/opencode/src/config/config.ts
@@ -653,6 +653,7 @@ export namespace Config {
         .default("<leader>h")
         .describe("Toggle code block concealment in messages"),
       tool_details: z.string().optional().default("none").describe("Toggle tool details visibility"),
+      sidebar_overlay_toggle: z.string().optional().default("none").describe("Toggle sidebar overlay mode"),
       model_list: z.string().optional().default("<leader>m").describe("List available models"),
       model_cycle_recent: z.string().optional().default("f2").describe("Next recently used model"),
       model_cycle_recent_reverse: z.string().optional().default("shift+f2").describe("Previous recently used model"),