diff --git a/app.py b/app.py
index f9586bd..5bf8607 100644
--- a/app.py
+++ b/app.py
@@ -1,3 +1,4 @@
+import asyncio
 import base64
 import hashlib
 import json
@@ -129,15 +130,36 @@ def expo_clear_images():
             os.remove(os.path.join(root, file))
 
 @app.route('/expo_postprocess', methods=['POST'])
-def expo_postprocess():
+async def expo_postprocess():
+    global on_postprocessing
     if on_postprocessing:
         return jsonify({"status": "error", "message": "Postprocessing in progress"}), 503
-    print("Postprocessing")
+    
     on_postprocessing = True
-    expo_postprocess_main()
-    expo_clear_images()
+    print("Postprocessing")
+
+    # Wait until the directories have the same files or timeout
+    if not await wait_for_files_to_match(expo_openpose_dir, expo_raw_sd_dir):
+        print("Timeout reached, proceeding with postprocessing")
+
+    await asyncio.to_thread(expo_postprocess_main)
+    await asyncio.to_thread(expo_clear_images)
     on_postprocessing = False
 
+    return jsonify({"status": "success", "message": "Postprocessing completed"}), 200
+
+
+async def wait_for_files_to_match(dir1: str, dir2: str, timeout: int = 60, interval: int = 1) -> bool:
+    start_time = asyncio.get_event_loop().time()
+    while asyncio.get_event_loop().time() - start_time < timeout:
+        files1 = set(os.listdir(dir1))
+        files2 = set(os.listdir(dir2))
+        if files1 == files2:
+            return True
+        await asyncio.sleep(interval)
+    return False
+
+
 @app.route('/gen_image', methods=['POST'])
 def gen_image():
     if request.is_json: