diff --git a/src/tui/overlay-key-routing.test.ts b/src/tui/overlay-key-routing.test.ts
new file mode 100644
index 000000000..d8c4b50f8
--- /dev/null
+++ b/src/tui/overlay-key-routing.test.ts
@@ -0,0 +1,110 @@
+/**
+ * CL-6723: with a suggestion/picker list open, keystrokes the list doesn't
+ * use are silently dropped instead of reaching the prompt — typed filter
+ * text can vanish without feedback. Unclaimed printables must reach the
+ * prompt buffer, whether the open surface is a plain picker or an ephemeral
+ * popup.
+ */
+import { describe, expect, test } from "bun:test";
+
+import { withTestRenderer } from "./harness";
+import type { PaletteCommand } from "./command-catalog";
+import { openPermissionsOverlay, openOperatorOverlay } from "./overlays";
+import { createAppShell } from "./shell/index";
+import type { AppShell } from "./shell/internals";
+import { isSlashPopupOpen } from "./shell/internals";
+import { openHelpOverlay, openPalette } from "./shell/palette";
+
+const CATALOG: readonly PaletteCommand[] = [
+  { id: "model", label: "/model" },
+  { id: "mcp", label: "/mcp" },
+];
+
+interface Ctx {
+  readonly shell: AppShell;
+  readonly press: (key: string) => void;
+}
+
+function withShell(fn: (ctx: Ctx) => Promise<void>): Promise<void> {
+  return withTestRenderer(
+    async (h) => {
+      const shell = createAppShell(h.renderer, {
+        terminal: { columns: 80, rows: 24 },
+        wireKeys: true,
+        run: "idle",
+        paletteCatalog: CATALOG,
+      });
+      try {
+        await fn({
+          shell,
+          press: (key) => h.pressKey(key as Parameters<typeof h.pressKey>[0]),
+        });
+      } finally {
+        shell.dispose();
+      }
+    },
+    { width: 80, height: 24 },
+  );
+}
+
+describe("unclaimed overlay keys reach the prompt", () => {
+  test("printable a non-filter picker ignores lands in the prompt", async () => {
+    await withShell(async ({ shell, press }) => {
+      openHelpOverlay(shell);
+      expect(shell.overlayList).not.toBeNull();
+      expect(shell.overlayKind).toBe("help");
+
+      press("x");
+      expect(shell.prompt.value).toBe("x");
+      expect(shell.overlayKind).toBe("help");
+    });
+  });
+
+  test("palette symmetry: unclaimed printable with a palette open reaches the prompt via the fallthrough", async () => {
+    await withShell(async ({ shell, press }) => {
+      openPalette(shell, { catalog: CATALOG });
+      expect(shell.overlayKind).toBe("palette");
+      expect(isSlashPopupOpen(shell)).toBe(false);
+
+      press("x");
+      expect(shell.prompt.value).toBe("x");
+      expect(shell.overlayKind).toBe("palette");
+    });
+  });
+
+  test("permission gate keeps printable keys: prompt stays empty, gate stays open", async () => {
+    await withShell(async ({ shell, press }) => {
+      openPermissionsOverlay(shell, { items: ["Allow once", "Deny"] });
+      expect(shell.overlayKind).toBe("permissions");
+
+      press("x");
+      expect(shell.prompt.value).toBe("");
+      expect(shell.overlayKind).toBe("permissions");
+    });
+  });
+
+  test("operator gate keeps printable keys: prompt stays empty, gate stays open", async () => {
+    await withShell(async ({ shell, press }) => {
+      openOperatorOverlay(shell, {
+        body: "Proceed?",
+        choices: ["Cancel", "Continue"],
+      });
+      expect(shell.overlayKind).toBe("operator");
+
+      press("x");
+      expect(shell.prompt.value).toBe("");
+      expect(shell.overlayKind).toBe("operator");
+    });
+  });
+
+  test("claimed overlay keys keep precedence over the prompt", async () => {
+    await withShell(async ({ shell, press }) => {
+      openHelpOverlay(shell);
+      const before = shell.overlayList?.activeIndex ?? 0;
+
+      press("j");
+      expect(shell.overlayList?.activeIndex).toBe(before + 1);
+      expect(shell.prompt.value).toBe("");
+    });
+  });
+});
diff --git a/src/tui/shell/keys.ts b/src/tui/shell/keys.ts
index e6c4a3077..0e93cfd95 100644
--- a/src/tui/shell/keys.ts
+++ b/src/tui/shell/keys.ts
@@ -437,6 +437,22 @@ export function createShellKeyHandlers(
           return;
         }
       }
+      // Unclaimed printables fall through to the prompt instead of vanishing:
+      // the prompt does not hold focus while the overlay is open, so the
+      // InputRenderable cannot insert them itself. Decision surfaces are the
+      // modal exception (focus-routing): a permission/operator gate keeps
+      // every key until it is answered or dismissed. The overlay stays open
+      // (no dismiss, no idle-notify) so a queued gate cannot drain mid-list.
+      if (
+        shell.overlayKind !== "permissions" &&
+        shell.overlayKind !== "operator" &&
+        isPrintableInsertKey(key)
+      ) {
+        key.preventDefault();
+        shell.prompt.insertText(key.sequence as string);
+        shell.sentHistory = sentHistoryOnEdit(shell.sentHistory);
+        return;
+      }
       return;
     }