Update app.py

app.py

@@ -45,7 +45,7 @@ def navigate(screenshot, task: str, platform: str, history):
     """
 
     # ───────────────────── normalise history input ──────────────────────────
-    messages=None
+    messages=[]
   
     if isinstance(history, str):
         try:
@@ -55,16 +55,13 @@ def navigate(screenshot, task: str, platform: str, history):
     else:
         messages = history
 
-    if messages is None or len(messages)==0:
-        prompt_header = (
-            "You are a GUI agent. You are given a task and your action history, "
-            "with screenshots. You need to perform the next action to complete "
-            "the task.\n\n## Output Format\n```\nThought: ...\nAction: ...\n```\n\n"
-            "## Action Space\nclick(start_box='...') / type(...)\n\n"
-            f"### Task\n{task}"
+    prompt_header = (
+            "You are a GUI agent. You are given a task and your action history, with screenshots." 
+            "You need to perform the next action to complete the task. \n\n## Output Format\n```\nThought: ...\nAction: ...\n```\n\n## Action Space\n\nclick(start_box='\u003c|box_start|\u003e(x1, y1)\u003c|box_end|\u003e')\nleft_double(start_box='\u003c|box_start|\u003e(x1, y1)\u003c|box_end|\u003e')\nright_single(start_box='\u003c|box_start|\u003e(x1, y1)\u003c|box_end|\u003e')\ndrag(start_box='\u003c|box_start|\u003e(x1, y1)\u003c|box_end|\u003e', end_box='\u003c|box_start|\u003e(x3, y3)\u003c|box_end|\u003e')\nhotkey(key='')\ntype(content='') #If you want to submit your input, use \"\\n\" at the end of `content`.\nscroll(start_box='\u003c|box_start|\u003e(x1, y1)\u003c|box_end|\u003e', direction='down or up or right or left')\nwait() #Sleep for 5s and take a screenshot to check for any changes.\nfinished(content='xxx') # Use escape characters \\', \\\", and \\n in content part to ensure we can parse the content in normal python string format.\n\n\n## Note\n- Use English in `Thought` part.\n- Write a small plan and finally summarize your next action (with its target element) in one sentence in `Thought` part.\n\n"
+            f"## User Instruction\n{task}"
         )
-        user_history = [{"role":"user","content":[{"type":"text","text":prompt_header},{"type": "image_url", "image_url":screenshot}]}]
-        messages = user_history
+    current = [{"role":"user","content":[{"type":"text","text":prompt_header},{"type": "image_url", "image_url":screenshot}]}]
+    messages.append(current)
 
     # ─────────────────────────── model forward ─────────────────────────────
     text = processor.apply_chat_template(