diff --git a/bot/api.py b/bot/api.py
index cb21e13..751db97 100644
--- a/bot/api.py
+++ b/bot/api.py
@@ -1746,9 +1746,9 @@ def get_autonomous_stats():
 
 @app.get("/conversation/{user_id}")
 def get_conversation(user_id: str):
-    if user_id in globals.conversation_history:
-        return {"conversation": list(globals.conversation_history[user_id])}
-    return {"conversation": []}
+    """Get conversation history for a user/channel (uses centralized ConversationHistory)."""
+    messages = conversation_history.get_recent_messages(user_id)
+    return {"conversation": [{"author": author, "content": content, "is_bot": is_bot} for author, content, is_bot in messages]}
 
 # ========== Figurine DM Subscription APIs ==========
 @app.get("/figurines/subscribers")
diff --git a/bot/commands/actions.py b/bot/commands/actions.py
index 4c01b9d..8ebd553 100644
--- a/bot/commands/actions.py
+++ b/bot/commands/actions.py
@@ -4,6 +4,7 @@ import asyncio
 import globals
 from utils.moods import load_mood_description
 from utils.scheduled import send_bedtime_reminder
+from utils.conversation_history import conversation_history
 from utils.logger import get_logger
 
 logger = get_logger('commands')
@@ -32,7 +33,7 @@ def calm_miku() -> str:
 
 
 def reset_conversation(user_id):
-    globals.conversation_history[str(user_id)].clear()
+    conversation_history.clear_channel(str(user_id))
 
 
 async def force_sleep() -> str:
diff --git a/bot/globals.py b/bot/globals.py
index 788d37d..934e463 100644
--- a/bot/globals.py
+++ b/bot/globals.py
@@ -1,14 +1,10 @@
 # globals.py
 import os
-from collections import defaultdict, deque
 import discord
 from apscheduler.schedulers.asyncio import AsyncIOScheduler
 
 scheduler = AsyncIOScheduler()
 
-# Stores last 5 exchanges per user (as deque)
-conversation_history = defaultdict(lambda: deque(maxlen=5))
-
 DISCORD_BOT_TOKEN = os.getenv("DISCORD_BOT_TOKEN")
 
 # Autonomous V2 Debug Mode (set to True to see detailed decision logging)
diff --git a/bot/utils/bipolar_mode.py b/bot/utils/bipolar_mode.py
index 639916a..03bb595 100644
--- a/bot/utils/bipolar_mode.py
+++ b/bot/utils/bipolar_mode.py
@@ -1034,8 +1034,8 @@ async def run_argument(channel: discord.TextChannel, client, trigger_context: st
                     
                     # Clean up argument conversation history
                     try:
-                        conversation_history.clear_history(argument_user_id)
-                    except:
+                        conversation_history.clear_channel(argument_user_id)
+                    except Exception:
                         pass  # History cleanup is not critical
                     
                     end_argument(channel_id)
diff --git a/bot/utils/figurine_notifier.py b/bot/utils/figurine_notifier.py
index d1db068..3e3f22a 100644
--- a/bot/utils/figurine_notifier.py
+++ b/bot/utils/figurine_notifier.py
@@ -5,8 +5,8 @@ from datetime import datetime
 from typing import List, Dict, Any, Tuple
 
 import discord
-import globals
 
+from utils.conversation_history import conversation_history
 from utils.twitter_fetcher import fetch_figurine_tweets_latest
 from utils.image_handling import analyze_image_with_qwen, download_and_encode_image
 from utils.llm import query_llama
@@ -204,15 +204,11 @@ async def send_figurine_dm_to_user(client: discord.Client, user_id: int, tweet:
         # Log the comment message
         dm_logger.log_user_message(user, comment_message, is_bot_message=True)
         
-        # IMPORTANT: Also add to globals.conversation_history for LLM context
+        # Add to conversation history for LLM context (uses centralized ConversationHistory)
         user_id_str = str(user_id)
-        
-        # Add the tweet URL as a "system message" about what Miku just sent (use original URL for context)
         tweet_context = f"[I just sent you this figurine tweet: {tweet_url}]"
-        
-        # Add the figurine comment to conversation history 
-        # Use empty user prompt since this was initiated by Miku
-        globals.conversation_history.setdefault(user_id_str, []).append((tweet_context, miku_comment))
+        conversation_history.add_message(channel_id=user_id_str, author_name="Miku", content=tweet_context, is_bot=True)
+        conversation_history.add_message(channel_id=user_id_str, author_name="Miku", content=miku_comment, is_bot=True)
         
         logger.debug(f"Messages logged to both DM history and conversation context for user {user_id}")
 
diff --git a/bot/utils/llm.py b/bot/utils/llm.py
index dbdaaed..b898592 100644
--- a/bot/utils/llm.py
+++ b/bot/utils/llm.py
@@ -475,10 +475,6 @@ Please respond in a way that reflects this emotional tone.{pfp_context}"""
                             is_bot=True
                         )
                     
-                    # Also save to legacy globals for backward compatibility (skip error messages)
-                    if user_prompt and user_prompt.strip() and reply and reply.strip() and reply != "Someone tell Koko-nii there is a problem with my AI.":
-                        globals.conversation_history[user_id].append((user_prompt, reply))
-                    
                     return reply
                 else:
                     error_text = await response.text()