diff --git a/src/main/services/ExportService.ts b/src/main/services/ExportService.ts
index de08d27..01cb527 100644
--- a/src/main/services/ExportService.ts
+++ b/src/main/services/ExportService.ts
@@ -136,7 +136,6 @@ export class ExportService {
     totalBytes += Buffer.byteLength(indexJsonl, 'utf8');
 
     const manifest = composeManifest({
-      exportedAt: this.now().toISOString(),
       noteCount: notes.length,
       mediaCount
     });
diff --git a/src/main/services/exportFormat.ts b/src/main/services/exportFormat.ts
index e0eb5cd..86f31d0 100644
--- a/src/main/services/exportFormat.ts
+++ b/src/main/services/exportFormat.ts
@@ -253,14 +253,15 @@ export function composeIndexJsonl(
 // ---------------------------------------------------------------------------
 
 export function composeManifest(input: {
-  exportedAt: string;
   noteCount: number;
   mediaCount: number;
 }): string {
+  // exported_at 필드 의도적 제외 — note 변경 없이도 git sync 가 매 호출마다
+  // timestamp 갱신 1줄 commit 을 만들어 history 노이즈와 불필요한 push 유발.
+  // import path 는 inkling_export_version 만 read 하므로 안전.
   return JSON.stringify(
     {
       inkling_export_version: 1,
-      exported_at: input.exportedAt,
       note_count: input.noteCount,
       media_count: input.mediaCount
     },
diff --git a/tests/unit/exportFormat.test.ts b/tests/unit/exportFormat.test.ts
index ed7f611..bce1d67 100644
--- a/tests/unit/exportFormat.test.ts
+++ b/tests/unit/exportFormat.test.ts
@@ -230,16 +230,22 @@ describe('composeIndexJsonl', () => {
 });
 
 describe('composeManifest', () => {
-  it('emits pretty JSON with required fields', () => {
+  it('emits pretty JSON with required fields (timestamp-free)', () => {
     const m = composeManifest({
-      exportedAt: '2026-04-26T00:00:00.000Z',
       noteCount: 42,
       mediaCount: 17
     });
     const obj = JSON.parse(m);
     expect(obj.inkling_export_version).toBe(1);
-    expect(obj.exported_at).toBe('2026-04-26T00:00:00.000Z');
     expect(obj.note_count).toBe(42);
     expect(obj.media_count).toBe(17);
+    // exported_at 필드 제거 — sync git history noise 방지.
+    expect(obj.exported_at).toBeUndefined();
+  });
+
+  it('두 번 호출 결과 stable (sync no-op invariant — 같은 input 이면 git diff 0)', () => {
+    const a = composeManifest({ noteCount: 5, mediaCount: 2 });
+    const b = composeManifest({ noteCount: 5, mediaCount: 2 });
+    expect(a).toBe(b);
   });
 });