Add MCP tools integration for Discord bot

Major improvements to LiteLLM Discord bot with MCP (Model Context Protocol) tools support:

Features added:
- MCP tools discovery and integration with LiteLLM proxy
- Fetch and convert 40+ GitHub MCP tools to OpenAI format
- Tool calling flow with placeholder execution (pending MCP endpoint confirmation)
- Dynamic tool injection based on LiteLLM MCP server configuration
- Enhanced system prompt with tool usage guidance
- Added ENABLE_TOOLS environment variable for easy toggle
- Comprehensive debug logging for troubleshooting

Technical changes:
- Added httpx>=0.25.0 dependency for async MCP API calls
- Implemented get_available_mcp_tools() to query /v1/mcp/server and /v1/mcp/tools endpoints
- Convert MCP tool schemas to OpenAI function calling format
- Detect and handle tool_calls in model responses
- Added system_prompt.txt for customizable bot behavior
- Updated README with better documentation and setup instructions
- Created claude.md with detailed development notes and upgrade roadmap

Configuration:
- New ENABLE_TOOLS flag in .env to control MCP integration
- DEBUG_LOGGING for detailed execution logs
- System prompt file support for easy customization

Known limitations:
- Tool execution currently uses placeholders (MCP execution endpoint needs verification)
- Limited to 50 tools to avoid overwhelming the model
- Requires LiteLLM proxy with MCP server configured

Next steps:
- Verify correct LiteLLM MCP tool execution endpoint
- Implement actual tool execution via MCP proxy
- Test end-to-end GitHub operations through Discord

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

scripts/discordbot.py

@@ -3,33 +3,52 @@ import discord
 from discord.ext import commands
 from openai import OpenAI
 import base64
-import requests
-from io import BytesIO
-from collections import deque
 from dotenv import load_dotenv
-import json
-import datetime
 import aiohttp
 from typing import Dict, Any, List
+import tiktoken
+import httpx
 
 # Load environment variables
 load_dotenv()
 
 # Get environment variables
 DISCORD_TOKEN = os.getenv('DISCORD_TOKEN')
-OPENAI_API_KEY = os.getenv('OPENAI_API_KEY')
-OPENWEBUI_API_BASE = os.getenv('OPENWEBUI_API_BASE')
+LITELLM_API_KEY = os.getenv('LITELLM_API_KEY')
+LITELLM_API_BASE = os.getenv('LITELLM_API_BASE')
 MODEL_NAME = os.getenv('MODEL_NAME')
+SYSTEM_PROMPT_FILE = os.getenv('SYSTEM_PROMPT_FILE', './system_prompt.txt')
+MAX_HISTORY_TOKENS = int(os.getenv('MAX_HISTORY_TOKENS', '3000'))
+DEBUG_LOGGING = os.getenv('DEBUG_LOGGING', 'false').lower() == 'true'
+ENABLE_TOOLS = os.getenv('ENABLE_TOOLS', 'false').lower() == 'true'
 
-# Configure OpenAI client to point to OpenWebUI
+def debug_log(message: str):
+    """Print debug message if DEBUG_LOGGING is enabled"""
+    if DEBUG_LOGGING:
+        print(f"[DEBUG] {message}")
+
+# Load system prompt from file
+def load_system_prompt():
+    """Load system prompt from file, with fallback to default"""
+    try:
+        with open(SYSTEM_PROMPT_FILE, 'r', encoding='utf-8') as f:
+            return f.read().strip()
+    except FileNotFoundError:
+        return "You are a helpful AI assistant integrated into Discord."
+
+SYSTEM_PROMPT = load_system_prompt()
+
+# Configure OpenAI client to point to LiteLLM
 client = OpenAI(
-    api_key=os.getenv('OPENAI_API_KEY'),
-    base_url=os.getenv('OPENWEBUI_API_BASE')  # e.g., "http://localhost:8080/v1"
+    api_key=LITELLM_API_KEY,
+    base_url=LITELLM_API_BASE  # e.g., "http://localhost:4000"
 )
 
-# Configure OpenAI
-# TODO: The 'openai.api_base' option isn't read in the client API. You will need to pass it when you instantiate the client, e.g. 'OpenAI(base_url=OPENWEBUI_API_BASE)'
-# openai.api_base = OPENWEBUI_API_BASE
+# Initialize tokenizer for token counting
+try:
+    encoding = tiktoken.encoding_for_model("gpt-4")
+except KeyError:
+    encoding = tiktoken.get_encoding("cl100k_base")
 
 # Initialize Discord bot
 intents = discord.Intents.default()
@@ -37,44 +56,257 @@ intents.message_content = True
 intents.messages = True
 bot = commands.Bot(command_prefix='!', intents=intents)
 
-# Message history cache
-channel_history = {}
+# Message history cache - stores recent conversations per channel
+channel_history: Dict[int, List[Dict[str, Any]]] = {}
 
-async def download_image(url):
-    response = requests.get(url)
-    if response.status_code == 200:
-        image_data = BytesIO(response.content)
-        base64_image = base64.b64encode(image_data.read()).decode('utf-8')
-        return base64_image
+def count_tokens(text: str) -> int:
+    """Count tokens in a text string"""
+    try:
+        return len(encoding.encode(text))
+    except Exception:
+        # Fallback: rough estimate (1 token ≈ 4 characters)
+        return len(text) // 4
+
+async def download_image(url: str) -> str | None:
+    """Download image and convert to base64 using async aiohttp"""
+    try:
+        async with aiohttp.ClientSession() as session:
+            async with session.get(url, timeout=aiohttp.ClientTimeout(total=10)) as response:
+                if response.status == 200:
+                    image_data = await response.read()
+                    base64_image = base64.b64encode(image_data).decode('utf-8')
+                    return base64_image
+    except Exception as e:
+        print(f"Error downloading image from {url}: {e}")
     return None
 
-async def get_chat_history(channel, limit=100):
+async def get_available_mcp_tools():
+    """Query LiteLLM for available MCP servers and tools, convert to OpenAI format"""
+    try:
+        base_url = LITELLM_API_BASE.rstrip('/')
+        headers = {"x-litellm-api-key": LITELLM_API_KEY}
+
+        async with httpx.AsyncClient(timeout=30.0) as http_client:
+            # Get MCP server configuration
+            server_response = await http_client.get(
+                f"{base_url}/v1/mcp/server",
+                headers=headers
+            )
+
+            if server_response.status_code == 200:
+                server_info = server_response.json()
+                debug_log(f"MCP server info: found {len(server_info) if isinstance(server_info, list) else 0} servers")
+
+                # Get available MCP tools
+                tools_response = await http_client.get(
+                    f"{base_url}/v1/mcp/tools",
+                    headers=headers
+                )
+
+                if tools_response.status_code == 200:
+                    tools_data = tools_response.json()
+
+                    # Tools come in format: {"tools": [...]}
+                    mcp_tools = tools_data.get("tools", []) if isinstance(tools_data, dict) else tools_data
+                    debug_log(f"Found {len(mcp_tools) if isinstance(mcp_tools, list) else 0} MCP tools")
+
+                    # Convert MCP tools to OpenAI function calling format
+                    openai_tools = []
+                    for tool in mcp_tools[:50]:  # Limit to first 50 tools to avoid overwhelming the model
+                        if isinstance(tool, dict) and "name" in tool:
+                            openai_tool = {
+                                "type": "function",
+                                "function": {
+                                    "name": tool["name"],
+                                    "description": tool.get("description", ""),
+                                    "parameters": tool.get("inputSchema", {})
+                                }
+                            }
+                            openai_tools.append(openai_tool)
+
+                    debug_log(f"Converted {len(openai_tools)} tools to OpenAI format")
+
+                    # Return both server info and converted tools
+                    return {
+                        "server": server_info,
+                        "tools": openai_tools,
+                        "tool_count": len(openai_tools)
+                    }
+                else:
+                    debug_log(f"MCP tools endpoint returned {tools_response.status_code}: {tools_response.text}")
+            else:
+                debug_log(f"MCP server endpoint returned {server_response.status_code}: {server_response.text}")
+
+    except Exception as e:
+        debug_log(f"Error fetching MCP tools: {e}")
+
+    return None
+
+async def get_chat_history(channel, bot_user_id: int, limit: int = 50) -> List[Dict[str, Any]]:
+    """
+    Retrieve chat history and format as proper conversation messages.
+    Only includes messages relevant to bot conversations.
+    Returns list of message dicts with proper role attribution.
+    Supports both regular channels and threads.
+    """
     messages = []
+    total_tokens = 0
+
+    # Check if this is a thread
+    is_thread = isinstance(channel, discord.Thread)
+
+    debug_log(f"Fetching history - is_thread: {is_thread}, channel: {channel.name if hasattr(channel, 'name') else 'DM'}")
+
+    # For threads, we want ALL messages in the thread (not just bot-related)
+    # For channels, we only want bot-related messages
+
+    message_count = 0
+    skipped_system = 0
+
+    # For threads, fetch the context including parent message if it exists
+    if is_thread:
+        try:
+            # Get the starter message (first message in thread)
+            if channel.starter_message:
+                starter = channel.starter_message
+            else:
+                starter = await channel.fetch_message(channel.id)
+
+            # If the starter message is replying to another message, fetch that parent
+            if starter and starter.reference and starter.reference.message_id:
+                try:
+                    parent_message = await channel.parent.fetch_message(starter.reference.message_id)
+                    if parent_message and (parent_message.type == discord.MessageType.default or parent_message.type == discord.MessageType.reply):
+                        is_bot_parent = parent_message.author.id == bot_user_id
+                        role = "assistant" if is_bot_parent else "user"
+                        content = f"{parent_message.author.display_name}: {parent_message.content}" if not is_bot_parent else parent_message.content
+
+                        # Remove bot mention if present
+                        if not is_bot_parent and bot_user_id:
+                            content = content.replace(f'<@{bot_user_id}>', '').strip()
+
+                        msg = {"role": role, "content": content}
+                        msg_tokens = count_tokens(content)
+
+                        if msg_tokens <= MAX_HISTORY_TOKENS:
+                            messages.append(msg)
+                            total_tokens += msg_tokens
+                            message_count += 1
+                            debug_log(f"Added parent message: role={role}, content_preview={content[:50]}...")
+                except Exception as e:
+                    debug_log(f"Could not fetch parent message: {e}")
+
+            # Add the starter message itself
+            if starter and (starter.type == discord.MessageType.default or starter.type == discord.MessageType.reply):
+                is_bot_starter = starter.author.id == bot_user_id
+                role = "assistant" if is_bot_starter else "user"
+                content = f"{starter.author.display_name}: {starter.content}" if not is_bot_starter else starter.content
+
+                # Remove bot mention if present
+                if not is_bot_starter and bot_user_id:
+                    content = content.replace(f'<@{bot_user_id}>', '').strip()
+
+                msg = {"role": role, "content": content}
+                msg_tokens = count_tokens(content)
+
+                if total_tokens + msg_tokens <= MAX_HISTORY_TOKENS:
+                    messages.append(msg)
+                    total_tokens += msg_tokens
+                    message_count += 1
+                    debug_log(f"Added thread starter: role={role}, content_preview={content[:50]}...")
+        except Exception as e:
+            debug_log(f"Could not fetch thread messages: {e}")
+
+    # Fetch history from the channel/thread
     async for message in channel.history(limit=limit):
-        content = f"{message.author.name}: {message.content}"
-        
-        # Handle attachments (images)
-        for attachment in message.attachments:
-            if any(attachment.filename.lower().endswith(ext) for ext in ['.png', '.jpg', '.jpeg', '.gif', '.webp']):
-                content += f" [Image: {attachment.url}]"
-        
-        messages.append(content)
-    return "\n".join(reversed(messages))
+        message_count += 1
+
+        # Skip system messages (thread starters, pins, etc.)
+        if message.type != discord.MessageType.default and message.type != discord.MessageType.reply:
+            skipped_system += 1
+            debug_log(f"Skipping system message type: {message.type}")
+            continue
+
+        # Determine if we should include this message
+        is_bot_message = message.author.id == bot_user_id
+        is_bot_mentioned = any(mention.id == bot_user_id for mention in message.mentions)
+        is_dm = isinstance(channel, discord.DMChannel)
+
+        # In threads: include ALL messages for full context
+        # In regular channels: only include bot-related messages
+        # In DMs: include all messages
+        if is_thread or is_dm:
+            should_include = True
+        else:
+            should_include = is_bot_message or is_bot_mentioned
+
+        if not should_include:
+            continue
+
+        # Determine role
+        role = "assistant" if is_bot_message else "user"
+
+        # Build content with author name in threads for multi-user context
+        if is_thread and not is_bot_message:
+            # Include username in threads for clarity
+            content = f"{message.author.display_name}: {message.content}"
+        else:
+            content = message.content
+
+        # Remove bot mention from user messages
+        if not is_bot_message and is_bot_mentioned:
+            content = content.replace(f'<@{bot_user_id}>', '').strip()
+
+        # Note: We'll handle images separately in the main flow
+        # For history, we just note that images were present
+        if message.attachments:
+            image_count = sum(1 for att in message.attachments
+                            if any(att.filename.lower().endswith(ext)
+                                 for ext in ['.png', '.jpg', '.jpeg', '.gif', '.webp']))
+            if image_count > 0:
+                content += f" [attached {image_count} image(s)]"
+
+        # Add to messages with token counting
+        msg = {"role": role, "content": content}
+        msg_tokens = count_tokens(content)
+
+        # Check if adding this message would exceed token limit
+        if total_tokens + msg_tokens > MAX_HISTORY_TOKENS:
+            break
+
+        messages.append(msg)
+        total_tokens += msg_tokens
+        debug_log(f"Added message: role={role}, content_preview={content[:50]}...")
+
+    # Reverse to get chronological order (oldest first)
+    debug_log(f"Processed {message_count} messages, skipped {skipped_system} system messages")
+    debug_log(f"Total messages collected: {len(messages)}, total tokens: {total_tokens}")
+    return list(reversed(messages))
 
 
-async def get_ai_response(context, user_message, image_urls=None):
-    
-    system_message = f"\"\"\"Previous conversation context:{context}"""
+async def get_ai_response(history_messages: List[Dict[str, Any]], user_message: str, image_urls: List[str] = None) -> str:
+    """
+    Get AI response using LiteLLM with proper conversation history and tool calling support.
 
-    messages = [
-        {"role": "system", "content": system_message},
-        {"role": "user", "content": [] if image_urls else user_message}
-    ]
-    
-    # Handle messages with images differently
+    Args:
+        history_messages: List of previous conversation messages with roles
+        user_message: Current user message
+        image_urls: Optional list of image URLs to include
+
+    Returns:
+        AI response string
+    """
+    # Start with system prompt
+    messages = [{"role": "system", "content": SYSTEM_PROMPT}]
+
+    # Add conversation history
+    messages.extend(history_messages)
+
+    # Build current user message
     if image_urls:
+        # Multi-modal message with text and images
         content_parts = [{"type": "text", "text": user_message}]
-        
+
         for url in image_urls:
             base64_image = await download_image(url)
             if base64_image:
@@ -84,16 +316,77 @@ async def get_ai_response(context, user_message, image_urls=None):
                         "url": f"data:image/jpeg;base64,{base64_image}"
                     }
                 })
-        messages[1]["content"] = content_parts
+        messages.append({"role": "user", "content": content_parts})
+    else:
+        # Text-only message
+        messages.append({"role": "user", "content": user_message})
 
     try:
-        response = client.chat.completions.create(
-            model=MODEL_NAME,
-            messages=messages
-        )
+        # Build request parameters
+        request_params = {
+            "model": MODEL_NAME,
+            "messages": messages,
+            "temperature": 0.7,
+        }
+
+        # Add MCP tools if enabled
+        if ENABLE_TOOLS:
+            debug_log("Tools enabled - fetching and converting MCP tools")
+
+            # Query and convert MCP tools to OpenAI format
+            mcp_info = await get_available_mcp_tools()
+            if mcp_info and isinstance(mcp_info, dict):
+                openai_tools = mcp_info.get("tools", [])
+                if openai_tools and isinstance(openai_tools, list) and len(openai_tools) > 0:
+                    request_params["tools"] = openai_tools
+                    request_params["tool_choice"] = "auto"
+                    debug_log(f"Added {len(openai_tools)} tools to request")
+                else:
+                    debug_log("No tools available to add to request")
+            else:
+                debug_log("Failed to fetch MCP tools")
+
+        debug_log(f"Calling chat completions with {len(request_params.get('tools', []))} tools")
+        response = client.chat.completions.create(**request_params)
+
+        # Handle tool calls if present
+        response_message = response.choices[0].message
+        tool_calls = getattr(response_message, 'tool_calls', None)
+
+        if tool_calls and len(tool_calls) > 0:
+            debug_log(f"Model requested {len(tool_calls)} tool calls")
+
+            # Add assistant's response with tool calls to messages
+            messages.append(response_message)
+
+            # Execute each tool call - add placeholder responses
+            # TODO: Implement actual MCP tool execution via LiteLLM proxy
+            for tool_call in tool_calls:
+                function_name = tool_call.function.name
+                function_args = tool_call.function.arguments
+
+                debug_log(f"Tool call requested: {function_name} with args: {function_args}")
+
+                # Placeholder response - in production this would execute via MCP
+                messages.append({
+                    "role": "tool",
+                    "tool_call_id": tool_call.id,
+                    "name": function_name,
+                    "content": f"Tool execution via MCP is being set up. Tool {function_name} was called with arguments: {function_args}"
+                })
+
+            # Get final response from model after tool execution
+            debug_log("Getting final response after tool execution")
+            final_response = client.chat.completions.create(**request_params)
+            return final_response.choices[0].message.content
+
         return response.choices[0].message.content
+
     except Exception as e:
-        return f"Error: {str(e)}"
+        error_msg = f"Error calling LiteLLM API: {str(e)}"
+        print(error_msg)
+        debug_log(f"Exception details: {e}")
+        return error_msg
 
 @bot.event
 async def on_message(message):
@@ -101,6 +394,10 @@ async def on_message(message):
     if message.author == bot.user:
         return
 
+    # Ignore system messages (thread starter, pins, etc.)
+    if message.type != discord.MessageType.default and message.type != discord.MessageType.reply:
+        return
+
     should_respond = False
 
     # Check if bot was mentioned
@@ -111,10 +408,32 @@ async def on_message(message):
     if isinstance(message.channel, discord.DMChannel):
         should_respond = True
 
+    # Check if message is in a thread
+    if isinstance(message.channel, discord.Thread):
+        # Check if thread was started from a bot message
+        try:
+            starter = message.channel.starter_message
+            if not starter:
+                starter = await message.channel.fetch_message(message.channel.id)
+
+            # If thread was started from bot's message, auto-respond
+            if starter and starter.author.id == bot.user.id:
+                should_respond = True
+                debug_log("Thread started by bot - auto-responding")
+            # If thread started from user message, only respond if mentioned
+            elif bot.user in message.mentions:
+                should_respond = True
+                debug_log("Thread started by user - responding due to mention")
+        except Exception as e:
+            debug_log(f"Could not determine thread starter: {e}")
+            # Default: only respond if mentioned
+            if bot.user in message.mentions:
+                should_respond = True
+
     if should_respond:
         async with message.channel.typing():
-            # Get chat history
-            history = await get_chat_history(message.channel)
+            # Get chat history with proper conversation format
+            history_messages = await get_chat_history(message.channel, bot.user.id)
 
             # Remove bot mention from the message
             user_message = message.content.replace(f'<@{bot.user.id}>', '').strip()
@@ -125,11 +444,17 @@ async def on_message(message):
                 if any(attachment.filename.lower().endswith(ext) for ext in ['.png', '.jpg', '.jpeg', '.gif', '.webp']):
                     image_urls.append(attachment.url)
 
-            # Get AI response
-            response = await get_ai_response(history, user_message, image_urls)
+            # Get AI response with proper conversation history
+            response = await get_ai_response(history_messages, user_message, image_urls if image_urls else None)
 
-            # Send response
-            await message.reply(response)
+            # Send response (split if too long for Discord's 2000 char limit)
+            if len(response) > 2000:
+                # Split into chunks
+                chunks = [response[i:i+2000] for i in range(0, len(response), 2000)]
+                for chunk in chunks:
+                    await message.reply(chunk)
+            else:
+                await message.reply(response)
 
     await bot.process_commands(message)
 
@@ -139,10 +464,16 @@ async def on_ready():
 
 
 def main():
-    if not all([DISCORD_TOKEN, OPENAI_API_KEY, OPENWEBUI_API_BASE, MODEL_NAME]):
+    if not all([DISCORD_TOKEN, LITELLM_API_KEY, LITELLM_API_BASE, MODEL_NAME]):
         print("Error: Missing required environment variables")
+        print(f"DISCORD_TOKEN: {'✓' if DISCORD_TOKEN else '✗'}")
+        print(f"LITELLM_API_KEY: {'✓' if LITELLM_API_KEY else '✗'}")
+        print(f"LITELLM_API_BASE: {'✓' if LITELLM_API_BASE else '✗'}")
+        print(f"MODEL_NAME: {'✓' if MODEL_NAME else '✗'}")
         return
 
+    print(f"System Prompt loaded from: {SYSTEM_PROMPT_FILE}")
+    print(f"Max history tokens: {MAX_HISTORY_TOKENS}")
     bot.run(DISCORD_TOKEN)
 
 if __name__ == "__main__":