diff --git a/.jules/bolt.md b/.jules/bolt.md
new file mode 100644
index 0000000..33ea382
--- /dev/null
+++ b/.jules/bolt.md
@@ -0,0 +1,6 @@
+## 2026-02-04 - XSync vs XFlush in Drawing
+**Learning:**  forces a blocking round-trip to the X server, which is catastrophic for frequent drawing operations like bar updates ().
+**Action:** Use  for drawing operations where the client doesn't need to wait for the server's response.
+## 2026-02-04 - XSync vs XFlush in Drawing
+**Learning:** `XSync` forces a blocking round-trip to the X server, which is catastrophic for frequent drawing operations like bar updates (`drw_map`).
+**Action:** Use `XFlush` for drawing operations where the client doesn't need to wait for the server's response.
diff --git a/drw.c b/drw.c
index 7e99a38..3eb6af8 100644
--- a/drw.c
+++ b/drw.c
@@ -494,7 +494,8 @@ void drw_map(Drw *drw, Window win, int x, int y, unsigned int w,
     }
 
     XCopyArea(drw->dpy, drw->drawable, win, drw->gc, x, y, w, h, x, y);
-    XSync(drw->dpy, False);
+    /* XFlush is sufficient and avoids blocking round-trip overhead of XSync */
+    XFlush(drw->dpy);
 }
 
 unsigned int drw_fontset_getwidth(Drw *drw, const char *text) {