diff --git a/CHANGELOG.md b/CHANGELOG.md
index 35e930b..6e019b9 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,14 @@
 # Changelog
 
+## v2.0.1 (2026-05-19)
+
+- Added Codex CLI/Desktop installation verifier to main page
+- Green check (✔) when detected, yellow cross (✘) when missing
+- "Install" button next to missing tools opens install guide dialog
+- Desktop/CLI launch buttons disabled with tooltip when tool is missing
+- Dependency status logged on startup
+- Buttons respect missing-state after busy/unbusy cycles
+
 ## v2.0.0 (2026-05-19)
 
 - Initial release: multi-provider Codex Launcher
diff --git a/codex-launcher_2.0.0_all.deb b/codex-launcher_2.0.0_all.deb
deleted file mode 100644
index 72613b1..0000000
Binary files a/codex-launcher_2.0.0_all.deb and /dev/null differ
diff --git a/codex-launcher_2.0.1_all.deb b/codex-launcher_2.0.1_all.deb
new file mode 100644
index 0000000..141678b
Binary files /dev/null and b/codex-launcher_2.0.1_all.deb differ
diff --git a/src/codex-launcher-gui b/src/codex-launcher-gui
index a7bf22e..6a65119 100755
--- a/src/codex-launcher-gui
+++ b/src/codex-launcher-gui
@@ -24,6 +24,11 @@ model_catalog_json = ""
 """
 
 CHANGELOG = [
+    ("2.0.1", "2026-05-19", [
+        "Added Codex CLI/Desktop installation verifier to main page",
+        "Disables Desktop/CLI launch buttons when corresponding tool is missing",
+        "Shows install instructions in status area on startup",
+    ]),
     ("2.0.0", "2026-05-19", [
         "Initial release: multi-provider Codex Launcher",
         "Translation proxy: Responses API to Chat Completions + Anthropic Messages",
@@ -429,6 +434,22 @@ def _last_log_lines(n=15):
     except Exception:
         return "(no log file)"
 
+def _detect_codex_cli():
+    try:
+        path = shutil.which("codex")
+        if not path:
+            return None
+        out = subprocess.run(["codex", "--version"], capture_output=True, text=True, timeout=5)
+        ver = (out.stdout or "").strip() or (out.stderr or "").strip() or "unknown"
+        return (path, ver)
+    except Exception:
+        return None
+
+def _detect_codex_desktop():
+    if START_SH.exists():
+        return str(START_SH)
+    return None
+
 # ═══════════════════════════════════════════════════════════════════
 # Main window
 # ═══════════════════════════════════════════════════════════════════
@@ -448,7 +469,7 @@ class LauncherWin(Gtk.Window):
         # header row
         hdr = Gtk.Box(spacing=8)
         vbox.pack_start(hdr, False, False, 0)
-        lbl = Gtk.Label(label="<b>Codex Launcher v2.0.0</b>")
+        lbl = Gtk.Label(label="<b>Codex Launcher v2.0.1</b>")
         lbl.set_use_markup(True)
         hdr.pack_start(lbl, False, False, 0)
         changelog_btn = Gtk.Button(label="Changelog")
@@ -458,6 +479,49 @@ class LauncherWin(Gtk.Window):
         mgr_btn.connect("clicked", lambda b: self._open_mgr())
         hdr.pack_end(mgr_btn, False, False, 0)
 
+        # verification status bar
+        self._cli_info = _detect_codex_cli()
+        self._desktop_info = _detect_codex_desktop()
+        ver_box = Gtk.Box(spacing=12)
+        vbox.pack_start(ver_box, False, False, 0)
+
+        if self._cli_info:
+            cli_path, cli_ver = self._cli_info
+            cli_lbl = Gtk.Label()
+            cli_lbl.set_markup(f"<span foreground='#2ea043'>✔ Codex CLI</span>  <small>{cli_ver} ({cli_path})</small>")
+            cli_lbl.set_use_markup(True)
+            ver_box.pack_start(cli_lbl, False, False, 0)
+        else:
+            cli_lbl = Gtk.Label()
+            cli_lbl.set_markup("<span foreground='#d29922'>✘ Codex CLI — not found</span>")
+            cli_lbl.set_use_markup(True)
+            ver_box.pack_start(cli_lbl, False, False, 0)
+            cli_install_btn = Gtk.Button(label="Install")
+            cli_install_btn.connect("clicked", lambda b: self._show_install_guide("cli"))
+            ver_box.pack_start(cli_install_btn, False, False, 0)
+
+        ver_box.pack_start(Gtk.Label(label="  "), False, False, 0)
+
+        if self._desktop_info:
+            desk_lbl = Gtk.Label()
+            desk_lbl.set_markup(f"<span foreground='#2ea043'>✔ Codex Desktop</span>  <small>({self._desktop_info})</small>")
+            desk_lbl.set_use_markup(True)
+            ver_box.pack_start(desk_lbl, False, False, 0)
+        else:
+            desk_lbl = Gtk.Label()
+            desk_lbl.set_markup("<span foreground='#d29922'>✘ Codex Desktop — not found</span>")
+            desk_lbl.set_use_markup(True)
+            ver_box.pack_start(desk_lbl, False, False, 0)
+            desk_install_btn = Gtk.Button(label="Install")
+            desk_install_btn.connect("clicked", lambda b: self._show_install_guide("desktop"))
+            ver_box.pack_start(desk_install_btn, False, False, 0)
+
+        self._missing = []
+        if not self._cli_info:
+            self._missing.append("cli")
+        if not self._desktop_info:
+            self._missing.append("desktop")
+
         ops_box = Gtk.Box(spacing=8)
         vbox.pack_start(ops_box, False, False, 0)
         self._refresh_all_btn = Gtk.Button(label="Refresh Models")
@@ -488,18 +552,30 @@ class LauncherWin(Gtk.Window):
         vbox.pack_start(btn_box, False, False, 8)
         self._btn_desktop = Gtk.Button(label="Launch Desktop")
         self._btn_desktop.connect("clicked", lambda b: self._launch("desktop"))
+        if "desktop" in self._missing:
+            self._btn_desktop.set_tooltip_text("Codex Desktop is not installed")
+            self._btn_desktop.set_sensitive(False)
         btn_box.pack_start(self._btn_desktop, True, True, 0)
         self._btn_cli = Gtk.Button(label="Launch CLI")
         self._btn_cli.connect("clicked", lambda b: self._launch("cli"))
+        if "cli" in self._missing:
+            self._btn_cli.set_tooltip_text("Codex CLI is not installed")
+            self._btn_cli.set_sensitive(False)
         btn_box.pack_start(self._btn_cli, True, True, 0)
 
         btn_box2 = Gtk.Box(spacing=8, homogeneous=True)
         vbox.pack_start(btn_box2, False, False, 0)
         self._btn_codex_desktop = Gtk.Button(label="Codex Default (Desktop)")
         self._btn_codex_desktop.connect("clicked", lambda b: self._launch_codex_default("desktop"))
+        if "desktop" in self._missing:
+            self._btn_codex_desktop.set_tooltip_text("Codex Desktop is not installed")
+            self._btn_codex_desktop.set_sensitive(False)
         btn_box2.pack_start(self._btn_codex_desktop, True, True, 0)
         self._btn_codex_cli = Gtk.Button(label="Codex Default (CLI)")
         self._btn_codex_cli.connect("clicked", lambda b: self._launch_codex_default("cli"))
+        if "cli" in self._missing:
+            self._btn_codex_cli.set_tooltip_text("Codex CLI is not installed")
+            self._btn_codex_cli.set_sensitive(False)
         btn_box2.pack_start(self._btn_codex_cli, True, True, 0)
 
         # status
@@ -529,6 +605,7 @@ class LauncherWin(Gtk.Window):
 
         self.show_all()
         self._rebuild_combo()
+        self._log_dependency_status()
 
     # ── helpers ──────────────────────────────────────────────────
 
@@ -542,14 +619,31 @@ class LauncherWin(Gtk.Window):
         self._tv.scroll_to_mark(m, 0.0, True, 0.0, 0.5)
         self._buf.delete_mark(m)
 
+    def _log_dependency_status(self):
+        if self._cli_info:
+            _, ver = self._cli_info
+            self.log(f"✔ Codex CLI detected ({ver})")
+        else:
+            self.log("✘ Codex CLI NOT found — CLI launch disabled. Click 'Install' above.")
+        if self._desktop_info:
+            self.log(f"✔ Codex Desktop detected ({self._desktop_info})")
+        else:
+            self.log("✘ Codex Desktop NOT found — Desktop launch disabled. Click 'Install' above.")
+        if self._missing:
+            self.log("⚠  Install missing tools before using the launcher.")
+        else:
+            self.log("All dependencies OK.")
+
     def _set_busy(self, busy):
-        GLib.idle_add(lambda: (
-            self._btn_desktop.set_sensitive(not busy),
-            self._btn_cli.set_sensitive(not busy),
-            self._btn_codex_desktop.set_sensitive(not busy),
-            self._btn_codex_cli.set_sensitive(not busy),
-            self._kill_btn.set_sensitive(busy),
-        ))
+        def _update():
+            has_cli = "cli" not in self._missing
+            has_desk = "desktop" not in self._missing
+            self._btn_desktop.set_sensitive(not busy and has_desk)
+            self._btn_cli.set_sensitive(not busy and has_cli)
+            self._btn_codex_desktop.set_sensitive(not busy and has_desk)
+            self._btn_codex_cli.set_sensitive(not busy and has_cli)
+            self._kill_btn.set_sensitive(busy)
+        GLib.idle_add(_update)
 
     def _rebuild_combo(self):
         self._endpoints_data = load_endpoints()
@@ -746,6 +840,31 @@ class LauncherWin(Gtk.Window):
         d.run()
         d.destroy()
 
+    def _show_install_guide(self, which):
+        if which == "cli":
+            title = "Install Codex CLI"
+            guide = (
+                "Codex CLI is required to use CLI launch features.\n\n"
+                "Install with npm:\n"
+                "  npm install -g @openai/codex\n\n"
+                "Or download from:\n"
+                "  https://github.com/openai/codex\n\n"
+                "After installing, restart the launcher."
+            )
+        else:
+            title = "Install Codex Desktop"
+            guide = (
+                "Codex Desktop is required to use Desktop launch features.\n\n"
+                "Expected location: /opt/codex-desktop/start.sh\n\n"
+                "Download from:\n"
+                "  https://codex.desktop.openai.com\n\n"
+                "After installing, restart the launcher."
+            )
+        d = Gtk.MessageDialog(self, 0, Gtk.MessageType.INFO, Gtk.ButtonsType.OK, guide)
+        d.set_title(title)
+        d.run()
+        d.destroy()
+
     # ── launch ───────────────────────────────────────────────────
 
     def _launch(self, target):