diff --git a/mas_arena/agents/mad.py b/mas_arena/agents/mad.py
new file mode 100644
index 0000000..30eb7fb
--- /dev/null
+++ b/mas_arena/agents/mad.py
@@ -0,0 +1,243 @@
+import json
+import os
+from dotenv import load_dotenv
+from dataclasses import dataclass
+from typing import Dict, Any, List
+
+from langchain_openai import ChatOpenAI
+from langchain_core.messages import SystemMessage, HumanMessage
+from mas_arena.agents.base import AgentSystem, AgentSystemRegistry
+
+load_dotenv(override=True)
+
+@dataclass
+class DebateAgent:
+    """Represents a debate participant"""
+    agent_id: str
+    name: str
+    model_name: str
+    temperature: float
+    memory_lst: List[Dict[str, str]] = None
+    
+    def __post_init__(self):
+        if self.memory_lst is None:
+            self.memory_lst = []
+        self.llm = ChatOpenAI(
+            model=self.model_name,
+            temperature=self.temperature,
+            request_timeout=60,
+            max_retries=2
+        )
+
+    def set_meta_prompt(self, meta_prompt: str):
+        """Set meta prompt"""
+        self.memory_lst.append({"role": "system", "content": meta_prompt})
+
+    def add_event(self, event: str):
+        """Add new event to memory"""
+        self.memory_lst.append({"role": "user", "content": event})
+
+    def add_memory(self, memory: str):
+        """Add generated response to memory"""
+        self.memory_lst.append({"role": "assistant", "content": memory})
+
+    async def ask(self):
+        """Query and get response"""
+        from langchain_core.messages import AIMessage
+        
+        messages = []
+        for msg in self.memory_lst:
+            if msg["role"] == "system":
+                messages.append(SystemMessage(content=msg["content"]))
+            elif msg["role"] == "user":
+                messages.append(HumanMessage(content=msg["content"]))
+            elif msg["role"] == "assistant":
+                messages.append(AIMessage(content=msg["content"]))
+        
+        response = await self.llm.ainvoke(messages)
+        response.name = self.name
+        response.id = self.agent_id
+        return response
+
+class MADAgent(AgentSystem):
+    """Multi-Agent Debate system"""
+    
+    def __init__(self, name: str = "mad", config: Dict[str, Any] = None):
+        super().__init__(name, config)
+        self.config = config or {}
+        self.num_players = self.config.get("num_players", 3)
+        self.max_round = self.config.get("max_round", 3)
+        self.model_name = self.config.get("model_name") or os.getenv("MODEL_NAME", "gpt-4o-mini")
+        self.temperature = self.config.get("temperature", 0)
+        
+        # Debate configuration
+        self.debate_config = {
+            
+    "debate_topic": "",
+    "base_answer": "",
+    "debate_answer": "",
+    "player_meta_prompt": "You are a debater. Hello and welcome to the debate. It's not necessary to fully agree with each other's perspectives, as our objective is to find the correct answer.\nThe debate topic is stated as follows:\n##debate_topic##",
+    "moderator_meta_prompt": "You are a moderator overseeing a debate on the topic: \"##debate_topic##\". Your role is to evaluate arguments and determine the correct answer. **IMPORTANT: You must output your decision in a strict JSON format. The final answer within the JSON must EXACTLY follow the format: {format_prompt}. All backslashes in the answer must be escaped (e.g., use `\\\\` for a single backslash).**",
+    "affirmative_prompt": "##debate_topic##",
+    "negative_prompt": "##aff_ans##\n\nYou disagree with my answer. Provide your answer and reasons.",
+    "moderator_prompt": "Now the ##round## round of debate for both sides has ended.\n\nAffirmative side arguing:\n##aff_ans##\n\nNegative side arguing: ##neg_ans##\n\nYou, as the moderator, will evaluate both sides' answers. If a clear preference emerges, summarize your reasons, declare the supported side, and provide the final correct answer. If not, the debate continues. **Please output your decision strictly in JSON format as follows, with no additional text: {{\"Whether there is a preference\": \"Yes or No\", \"Supported Side\": \"Affirmative or Negative\", \"Reason\": \"Your reason here.\", \"debate_answer\": \"The final answer here, escaping backslashes.\"}}**",
+    "judge_prompt_last1": "Affirmative side arguing: ##aff_ans##\n\nNegative side arguing: ##neg_ans##\n\nNow, what answer candidates do we have? Present them without reasons.",
+    "judge_prompt_last2": "Therefore, ##debate_topic##\nPlease summarize your reasons and give the final answer that you think is correct. **IMPORTANT: You must output your decision in a strict JSON format as follows, with no additional text: {{\"Whether there is a preference\": \"Yes\", \"Supported Side\": \"Affirmative or Negative based on your judgement\", \"Reason\": \"Your reason here.\", \"debate_answer\": \"The final answer here, escaping backslashes.\"}}**",
+    "debate_prompt": "##oppo_ans##\n\nDo you agree with my perspective? Provide your reasons and your answer. **IMPORTANT: The debate_answer must EXACTLY follow the format: {format_prompt}.** The latex format requires **two backslashes to be output**"
+    }
+        
+        # Initialize components
+        agent_components = self._create_agents()
+        self.players = [w for w in agent_components["workers"] if isinstance(w, DebateAgent)]
+
+    def _create_agents(self) -> Dict[str, List]:
+        """Create debate participants and result extractor"""
+        name_list = ["Affirmative side", "Negative side", "Moderator"]
+        
+        players = []
+        for i, name in enumerate(name_list):
+            agent = DebateAgent(
+                agent_id=f"agent_{i+1}",
+                name=name,
+                model_name=self.model_name,
+                temperature=self.temperature
+            )
+            players.append(agent)
+
+        return {
+            "workers": players
+        }
+
+    def init_prompt(self, debate_topic: str):
+        """Initialize and replace placeholders in prompt templates"""
+        config = self.debate_config.copy()
+        for key in config:
+            if isinstance(config[key], str):
+                config[key] = config[key].replace("##debate_topic##", debate_topic)
+        return config
+
+    def round_dct(self, num: int) -> str:
+        """Convert number to ordinal word"""
+        dct = {
+            1: 'first', 2: 'second', 3: 'third', 4: 'fourth', 5: 'fifth', 
+            6: 'sixth', 7: 'seventh', 8: 'eighth', 9: 'ninth', 10: 'tenth'
+        }
+        return dct.get(num, str(num))
+
+    async def run_agent(self, problem: Dict[str, Any], **kwargs) -> Dict[str, Any]:
+        """Run debate process"""
+        
+        problem_text = problem["problem"]
+        
+        # Store all LLM responses
+        all_messages = []
+        
+        # Use format_prompt as debate topic
+        debate_topic = f"{problem_text}\n\n{self.format_prompt}" if self.format_prompt else problem_text
+        
+        # Initialize prompts
+        config = self.init_prompt(debate_topic)
+        
+        # Get participants
+        affirmative = self.players[0]
+        negative = self.players[1] 
+        moderator = self.players[2]
+        
+        # Clear memory for each agent to prevent context overflow
+        affirmative.memory_lst.clear()
+        negative.memory_lst.clear()
+        moderator.memory_lst.clear()
+        
+        # Set meta prompts
+        affirmative.set_meta_prompt(config['player_meta_prompt'])
+        negative.set_meta_prompt(config['player_meta_prompt'])
+        moderator.set_meta_prompt(config['moderator_meta_prompt'])
+        
+        # First round debate
+        affirmative.add_event(config['affirmative_prompt'])
+        aff_response = await affirmative.ask()
+        affirmative.add_memory(aff_response.content)
+        all_messages.append(aff_response)
+        aff_ans = aff_response.content
+        
+        negative.add_event(config['negative_prompt'].replace('##aff_ans##', aff_ans))
+        neg_response = await negative.ask()
+        negative.add_memory(neg_response.content)
+        all_messages.append(neg_response)
+        neg_ans = neg_response.content
+        
+        moderator.add_event(config['moderator_prompt'].replace('##aff_ans##', aff_ans).replace('##neg_ans##', neg_ans).replace('##round##', 'first'))
+        mod_response = await moderator.ask()
+        moderator.add_memory(mod_response.content)
+        all_messages.append(mod_response)
+        
+        try:
+            mod_ans = json.loads(mod_response.content)
+        except:
+            mod_ans = {"debate_answer": "", "Whether there is a preference": "No"}
+        
+        # Multi-round debate
+        for round_num in range(2, self.max_round + 1):
+            if mod_ans.get("debate_answer", "") != "":
+                break
+                
+            affirmative.add_event(config['debate_prompt'].replace('##oppo_ans##', neg_ans))
+            aff_response = await affirmative.ask()
+            affirmative.add_memory(aff_response.content)
+            all_messages.append(aff_response)
+            aff_ans = aff_response.content
+            
+            negative.add_event(config['debate_prompt'].replace('##oppo_ans##', aff_ans))
+            neg_response = await negative.ask()
+            negative.add_memory(neg_response.content)
+            all_messages.append(neg_response)
+            neg_ans = neg_response.content
+            
+            moderator.add_event(config['moderator_prompt'].replace('##aff_ans##', aff_ans).replace('##neg_ans##', neg_ans).replace('##round##', self.round_dct(round_num)))
+            mod_response = await moderator.ask()
+            moderator.add_memory(mod_response.content)
+            all_messages.append(mod_response)
+            
+            try:
+                mod_ans = json.loads(mod_response.content)
+            except:
+                mod_ans = {"debate_answer": "", "Whether there is a preference": "No"}
+        
+        # If still no consensus, use judge
+        final_answer = mod_ans.get("debate_answer", "")
+        if not final_answer:
+            judge = DebateAgent(
+                agent_id="judge",
+                name="Judge",
+                model_name=self.model_name,
+                temperature=self.temperature
+            )
+            judge.set_meta_prompt(config['moderator_meta_prompt'])
+            
+            # Get final answer candidates
+            judge.add_event(config['judge_prompt_last1'].replace('##aff_ans##', aff_ans).replace('##neg_ans##', neg_ans))
+            judge_response1 = await judge.ask()
+            judge.add_memory(judge_response1.content)
+            all_messages.append(judge_response1)
+            
+            # Select final answer
+            judge.add_event(config['judge_prompt_last2'])
+            judge_response2 = await judge.ask()
+            judge.add_memory(judge_response2.content)
+            all_messages.append(judge_response2)
+            
+            final_answer = judge_response2.content
+        
+        return {
+            "messages": all_messages,
+            "final_answer": final_answer
+        }
+
+# Register agent system
+AgentSystemRegistry.register(
+    "mad",
+    MADAgent,
+    num_players=3,
+    max_round=3,
+    temperature=0
+) 
\ No newline at end of file