diff --git a/src/main/index.ts b/src/main/index.ts
index 3051a2f..3b7b272 100644
--- a/src/main/index.ts
+++ b/src/main/index.ts
@@ -335,27 +335,35 @@ handleIpc("folio:getChapterContent", (_e, id: string) =>
   getChapterContent(requireBook(), id)
 );
 
-handleIpc("folio:createChapter", (_e, title: string) => {
-  const entry = createChapter(requireBook(), title);
+handleIpc("folio:createChapter", async (_e, title: string) => {
+  const bp = requireBook();
+  const entry = createChapter(bp, title);
   notifyChange();
+  void autoExportDocx(bp);
   return { id: entry.id, title: entry.title, file: entry.file };
 });
 
-handleIpc("folio:renameChapter", (_e, id: string, title: string) => {
-  renameChapter(requireBook(), id, title);
+handleIpc("folio:renameChapter", async (_e, id: string, title: string) => {
+  const bp = requireBook();
+  renameChapter(bp, id, title);
   notifyChange();
+  void autoExportDocx(bp);
   return { ok: true };
 });
 
-handleIpc("folio:deleteChapter", (_e, id: string) => {
-  deleteChapter(requireBook(), id);
+handleIpc("folio:deleteChapter", async (_e, id: string) => {
+  const bp = requireBook();
+  deleteChapter(bp, id);
   notifyChange();
+  void autoExportDocx(bp);
   return { ok: true };
 });
 
-handleIpc("folio:restoreChapter", (_e, snap: unknown) => {
-  restoreChapter(requireBook(), snap as never);
+handleIpc("folio:restoreChapter", async (_e, snap: unknown) => {
+  const bp = requireBook();
+  restoreChapter(bp, snap as never);
   notifyChange();
+  void autoExportDocx(bp);
   return { ok: true };
 });
 
@@ -401,21 +409,27 @@ function restoreBookFromTrash(p: string): { ok?: boolean; error?: string } {
 
 handleIpc("folio:restoreBook", (_e, p: string) => restoreBookFromTrash(p));
 
-handleIpc("folio:duplicateChapter", (_e, id: string, title?: string) => {
-  const entry = duplicateChapter(requireBook(), id, title);
+handleIpc("folio:duplicateChapter", async (_e, id: string, title?: string) => {
+  const bp = requireBook();
+  const entry = duplicateChapter(bp, id, title);
   notifyChange();
+  void autoExportDocx(bp);
   return { id: entry.id, title: entry.title };
 });
 
-handleIpc("folio:setChapterColor", (_e, id: string, color: string | null) => {
-  setChapterColor(requireBook(), id, color);
+handleIpc("folio:setChapterColor", async (_e, id: string, color: string | null) => {
+  const bp = requireBook();
+  setChapterColor(bp, id, color);
   notifyChange();
+  void autoExportDocx(bp);
   return { ok: true };
 });
 
-handleIpc("folio:reorderChapters", (_e, newOrder: string[]) => {
-  reorderChapters(requireBook(), newOrder);
+handleIpc("folio:reorderChapters", async (_e, newOrder: string[]) => {
+  const bp = requireBook();
+  reorderChapters(bp, newOrder);
   notifyChange();
+  void autoExportDocx(bp);
   return { ok: true };
 });
 
@@ -545,8 +559,10 @@ async function exportOffice(format: "docx" | "odt", chapterIds?: string[] | null
 handleIpc("folio:exportDocx", (_e, chapterIds) => exportOffice("docx", chapterIds));
 handleIpc("folio:exportOdt", (_e, chapterIds) => exportOffice("odt", chapterIds));
 
-handleIpc("folio:saveChapter", (_e, id: string, content: string) => {
-  setChapterContent(requireBook(), id, content);
+handleIpc("folio:saveChapter", async (_e, id: string, content: string) => {
+  const bp = requireBook();
+  setChapterContent(bp, id, content);
+  void autoExportDocx(bp);
   return { ok: true };
 });
 
@@ -583,8 +599,42 @@ handleIpc("folio:loadChapterDoc", (_e, id: string) =>
 
 // Persist a native document from the editor. Autosave writes directly to the
 // native JSON model (no Markdown round-trip).
-handleIpc("folio:saveChapterDoc", (_e, id: string, doc: unknown) => {
-  saveChapterDoc(requireBook(), id, doc as never);
+// Added: auto-export DOCX by default so every save also refreshes the
+// book's .docx in the book folder (and a per-chapter docx). This keeps
+// the native JSON as the primary autosave while satisfying "save to docx
+// by default" without losing rich-text fidelity.
+async function autoExportDocx(bookPath: string): Promise<void> {
+  try {
+    const meta = loadBook(bookPath);
+    const full = await buildDocx(bookPath);
+    const outFull = path.join(bookPath, `${meta.title}.docx`);
+    fs.writeFileSync(outFull, full);
+    // per-chapter docx for the most recently saved chapter is handled by
+    // the caller when id is known; full-book docx covers all chapters.
+  } catch (e) {
+    console.error("[folio] auto docx export failed:", (e as Error).message);
+  }
+}
+
+handleIpc("folio:saveChapterDoc", async (_e, id: string, doc: unknown) => {
+  const bp = requireBook();
+  saveChapterDoc(bp, id, doc as never);
+  // fire-and-forget full-book DOCX update (also per-chapter for quick access)
+  try {
+    const meta = loadBook(bp);
+    const entry = meta.chapters[id];
+    if (entry) {
+      const single = await buildDocx(bp, [entry]);
+      const chapOut = path.join(
+        bp,
+        `${entry.title.replace(/[\/\\:*?"<>|]/g, "_")}.docx`
+      );
+      fs.writeFileSync(chapOut, single);
+    }
+  } catch (e) {
+    console.error("[folio] per-chapter docx failed:", (e as Error).message);
+  }
+  void autoExportDocx(bp);
   return { ok: true };
 });