Add MCP delegation bridge and diagram tools

**Features Added**:

1. **Agent Registry (agent_registry.py)**
   - Thread-safe global singleton for MCP tool access to Agent instance
   - Enables MCP tools to call Agent.delegate() without circular imports
   - Registered at bot startup in bot_runner.py

2. **Sub-Agent Manager (sub_agent_manager.py)**
   - Watchdog system monitoring sub-agent lifecycle
   - Detects hung agents (5min timeout, 30s check interval)
   - Auto-cleanup and status tracking

3. **delegate_task MCP Tool (mcp_tools.py)**
   - Exposes Agent.delegate() to Claude via MCP protocol
   - Enables parallel sub-agent execution via tool calls
   - Supports specialist prompts and agent ID caching

4. **Memory Write Locks (memory_system.py)**
   - Thread-safe writes to prevent file corruption
   - Protects write_memory(), update_soul(), update_user()

5. **Diagram Tools**
   - Mermaid MCP server (flowcharts, sequence diagrams, etc.)
   - Excalidraw MCP server (hand-drawn style diagrams)
   - Config files in config/ directory

6. **Adapter Improvements**
   - Enhanced error handling across all adapters
   - Unified logging patterns

**Testing**: Ready for parallel sub-agent testing

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

adapters/base.py

@@ -145,6 +145,26 @@ class BaseAdapter(ABC):
     async def send_typing_indicator(self, channel_id: str) -> None:
         """Show typing indicator. Optional."""
 
+    async def send_file(
+        self,
+        channel_id: str,
+        file_path: str,
+        caption: Optional[str] = None,
+        thread_id: Optional[str] = None
+    ) -> Dict[str, Any]:
+        """Send a file attachment to the platform. Optional - override if supported.
+
+        Args:
+            channel_id: Channel/chat ID to send to
+            file_path: Absolute path to file
+            caption: Optional caption/text with the file
+            thread_id: Optional thread/reply ID
+
+        Returns:
+            Dict with success status and message_id or error
+        """
+        return {"success": False, "error": "send_file not implemented"}
+
     async def health_check(self) -> Dict[str, Any]:
         """Perform health check on the adapter."""
         return {

adapters/runtime.py

@@ -98,6 +98,61 @@ class AdapterRuntime:
             print("[Runtime] Warning: No event loop for message dispatch")
             self._message_queue.put_nowait(message)
 
+    async def _detect_and_send_diagrams(
+        self,
+        response: str,
+        adapter: BaseAdapter,
+        channel_id: str,
+        thread_id: Optional[str]
+    ) -> None:
+        """Detect diagram file paths in response and auto-send them.
+
+        Args:
+            response: Agent's text response
+            adapter: Platform adapter to send files with
+            channel_id: Channel/chat ID
+            thread_id: Thread/message ID for replies
+        """
+        import re
+        from pathlib import Path
+
+        # Match diagram file paths: "Saved to: path/to/diagram.png"
+        # Pattern matches common phrases followed by file path with image/diagram extensions
+        pattern = r"(?:Saved|Created|Generated|Exported|File saved|Output file)\s*(?:to|at)?[:\s]+([^\s]+\.(?:png|svg|pdf|jpg|jpeg))"
+        matches = re.findall(pattern, response, re.IGNORECASE)
+
+        if not matches:
+            return
+
+        sent_files = []
+        for file_path_str in matches:
+            try:
+                file_path = Path(file_path_str)
+
+                # Check if file exists
+                if not file_path.exists():
+                    print(f"[Runtime] Diagram file not found: {file_path}")
+                    continue
+
+                # Send file via adapter
+                result = await adapter.send_file(
+                    channel_id=channel_id,
+                    file_path=str(file_path.absolute()),
+                    caption=f"Diagram: {file_path.name}",
+                    thread_id=thread_id,
+                )
+
+                if result.get("success"):
+                    sent_files.append(file_path.name)
+                    print(f"[Runtime] Sent diagram file: {file_path.name}")
+                else:
+                    print(f"[Runtime] Failed to send diagram: {result.get('error')}")
+            except Exception as e:
+                print(f"[Runtime] Error sending diagram file: {e}")
+
+        if sent_files:
+            print(f"[Runtime] Successfully sent {len(sent_files)} diagram file(s)")
+
     async def _process_message_queue(self) -> None:
         """Background task to process incoming messages."""
         print("[Runtime] Message processing loop started")
@@ -169,12 +224,22 @@ class AdapterRuntime:
                 user_message=processed_message.text,
                 username=username,
                 progress_callback=progress_callback,
+                inbound_message=processed_message,
             )
 
             # Apply postprocessors
             for postprocessor in self._postprocessors:
                 response = postprocessor(response, processed_message)
 
+            # NEW: Detect and send diagram files mentioned in response
+            if adapter:
+                await self._detect_and_send_diagrams(
+                    response,
+                    adapter,
+                    message.channel_id,
+                    message.thread_id,
+                )
+
             # Send response back
             if adapter:
                 reply_to = (

adapters/slack/adapter.py

@@ -58,19 +58,29 @@ class SlackAdapter(BaseAdapter):
         )
 
     def validate_config(self) -> bool:
-        """Validate Slack configuration."""
+        """Validate Slack configuration.
+
+        Required scopes for bot token:
+        - files:read (for downloading file attachments)
+        - files:write (for uploading files - future feature)
+        """
         if not self.config.credentials:
             return False
 
         bot_token = self.config.credentials.get("bot_token", "")
         app_token = self.config.credentials.get("app_token", "")
 
-        return (
+        valid = (
             bool(bot_token and app_token)
             and bot_token.startswith("xoxb-")
             and app_token.startswith("xapp-")
         )
 
+        if valid:
+            print("[Slack] ✓ Config valid. Ensure bot has 'files:read' and 'files:write' scopes at api.slack.com")
+
+        return valid
+
     async def start(self) -> None:
         """Start the Slack Socket Mode connection."""
         if not self.validate_config():
@@ -116,9 +126,40 @@ class SlackAdapter(BaseAdapter):
             channel = event.get("channel")
             thread_ts = event.get("thread_ts")
             ts = event.get("ts")
+            files = event.get("files", [])
+
+            # DEBUG: Log full event structure
+            print(f"[Slack DEBUG] Event subtype: {event.get('subtype')}")
+            print(f"[Slack DEBUG] Event has text: {bool(text)}, text length: {len(text)}")
+            print(f"[Slack DEBUG] Event has files: {bool(files)}, file count: {len(files)}")
+
+            # DEBUG: Log file detection
+            if files:
+                print(f"[Slack DEBUG] Detected {len(files)} file(s) in message")
+                for f in files:
+                    print(f"[Slack DEBUG] File: {f.get('name')} ({f.get('mimetype')}, ID: {f.get('id')})")
 
             username = await self._get_username(user_id)
 
+            # Determine message type
+            message_type = MessageType.FILE if files else MessageType.TEXT
+
+            # Download files
+            downloaded_files = []
+            for file_info in files:
+                print(f"[Slack DEBUG] Downloading: {file_info.get('name')} (ID: {file_info.get('id')})")
+                result = await self._download_slack_file(file_info)
+                if result["success"]:
+                    print(f"[Slack DEBUG] Downloaded to: {result['file_path']}")
+                    downloaded_files.append(result)
+                else:
+                    print(f"[Slack] Failed to download file {file_info.get('name')}: {result['error']}")
+
+            # If files but no text, add placeholder
+            if files and not text:
+                file_names = ", ".join(f["filename"] for f in downloaded_files)
+                text = f"[Uploaded {len(downloaded_files)} file(s): {file_names}]"
+
             inbound_msg = InboundMessage(
                 platform="slack",
                 user_id=user_id,
@@ -127,11 +168,12 @@ class SlackAdapter(BaseAdapter):
                 channel_id=channel,
                 thread_id=thread_ts,
                 reply_to_id=None,
-                message_type=MessageType.TEXT,
+                message_type=message_type,
                 metadata={
                     "ts": ts,
                     "team": event.get("team"),
                     "channel_type": event.get("channel_type"),
+                    "files": downloaded_files,
                 },
                 raw=event,
             )
@@ -146,9 +188,35 @@ class SlackAdapter(BaseAdapter):
             channel = event.get("channel")
             thread_ts = event.get("thread_ts")
             ts = event.get("ts")
+            files = event.get("files", [])
+
+            # DEBUG: Log file detection
+            if files:
+                print(f"[Slack DEBUG @mention] Detected {len(files)} file(s)")
+                for f in files:
+                    print(f"[Slack DEBUG @mention] File: {f.get('name')} ({f.get('mimetype')})")
 
             username = await self._get_username(user_id)
 
+            # Determine message type
+            message_type = MessageType.FILE if files else MessageType.TEXT
+
+            # Download files
+            downloaded_files = []
+            for file_info in files:
+                print(f"[Slack DEBUG @mention] Downloading: {file_info.get('name')} (ID: {file_info.get('id')})")
+                result = await self._download_slack_file(file_info)
+                if result["success"]:
+                    print(f"[Slack DEBUG @mention] Downloaded to: {result['file_path']}")
+                    downloaded_files.append(result)
+                else:
+                    print(f"[Slack @mention] Failed to download file {file_info.get('name')}: {result['error']}")
+
+            # If files but no text (after stripping mention), add placeholder
+            if files and not text:
+                file_names = ", ".join(f["filename"] for f in downloaded_files)
+                text = f"[Uploaded {len(downloaded_files)} file(s): {file_names}]"
+
             inbound_msg = InboundMessage(
                 platform="slack",
                 user_id=user_id,
@@ -157,17 +225,88 @@ class SlackAdapter(BaseAdapter):
                 channel_id=channel,
                 thread_id=thread_ts,
                 reply_to_id=None,
-                message_type=MessageType.TEXT,
+                message_type=message_type,
                 metadata={
                     "ts": ts,
                     "mentioned": True,
                     "team": event.get("team"),
+                    "files": downloaded_files,
                 },
                 raw=event,
             )
 
             self._dispatch_message(inbound_msg)
 
+    async def _download_slack_file(
+        self,
+        file_info: Dict[str, Any],
+        output_dir: str = "downloads/slack"
+    ) -> Dict[str, Any]:
+        """Download a file from Slack using url_private_download.
+
+        Args:
+            file_info: File object from Slack event (contains url_private_download, name, etc.)
+            output_dir: Directory to save files (default: "downloads/slack")
+
+        Returns:
+            Dict with success, file_path, filename, mimetype, size, or error
+        """
+        import aiohttp
+        from pathlib import Path
+        from datetime import datetime
+
+        url = file_info.get("url_private_download")
+        token = self.config.credentials["bot_token"]
+        headers = {"Authorization": f"Bearer {token}"}
+
+        try:
+            async with aiohttp.ClientSession() as session:
+                async with session.get(url, headers=headers) as response:
+                    if response.status == 403:
+                        return {
+                            "success": False,
+                            "error": "Permission denied. Add 'files:read' scope to bot at api.slack.com → OAuth & Permissions → Bot Token Scopes"
+                        }
+                    elif response.status == 404:
+                        return {"success": False, "error": "File not found or expired"}
+                    elif response.status != 200:
+                        return {"success": False, "error": f"HTTP {response.status}"}
+
+                    content_type = response.headers.get("Content-Type", "")
+                    file_data = await response.read()
+
+                    # Detect HTML login page (auth failure)
+                    if content_type.startswith("text/html") or file_data.startswith(b"<!DOCTYPE") or file_data.startswith(b"<html"):
+                        print(f"[Slack] Auth failure: Got HTML instead of file (likely missing 'files:read' scope)")
+                        return {
+                            "success": False,
+                            "error": "Authentication failed. Bot needs 'files:read' scope. Add it at api.slack.com → OAuth & Permissions → Scopes → Add files:read → Reinstall to Workspace"
+                        }
+
+            # Save to disk
+            Path(output_dir).mkdir(parents=True, exist_ok=True)
+            safe_name = Path(file_info["name"]).name  # Prevent path traversal
+            file_path = Path(output_dir) / safe_name
+
+            # Handle duplicates with timestamp
+            if file_path.exists():
+                timestamp = datetime.now().strftime("%Y%m%d_%H%M%S")
+                stem, suffix = safe_name.rsplit(".", 1) if "." in safe_name else (safe_name, "")
+                safe_name = f"{stem}_{timestamp}.{suffix}" if suffix else f"{stem}_{timestamp}"
+                file_path = Path(output_dir) / safe_name
+
+            file_path.write_bytes(file_data)
+
+            return {
+                "success": True,
+                "file_path": str(file_path.absolute()),
+                "filename": safe_name,
+                "mimetype": file_info.get("mimetype", ""),
+                "size": len(file_data)
+            }
+        except Exception as e:
+            return {"success": False, "error": str(e)}
+
     async def send_message(
         self, message: OutboundMessage
     ) -> Dict[str, Any]:
@@ -256,6 +395,45 @@ class SlackAdapter(BaseAdapter):
                 "error": str(e.response.get("error")),
             }
 
+    async def send_file(
+        self,
+        channel_id: str,
+        file_path: str,
+        caption: Optional[str] = None,
+        thread_id: Optional[str] = None
+    ) -> Dict[str, Any]:
+        """Upload a file to Slack channel."""
+        if not self.app:
+            return {"success": False, "error": "Adapter not started"}
+
+        try:
+            from pathlib import Path
+            path = Path(file_path)
+
+            if not path.exists():
+                return {"success": False, "error": f"File not found: {file_path}"}
+
+            result = await self.app.client.files_upload_v2(
+                channel=channel_id,
+                file=str(path.absolute()),
+                title=path.name,
+                initial_comment=caption or "",
+                thread_ts=thread_id,
+            )
+
+            return {
+                "success": True,
+                "message_id": result["file"]["id"],
+                "file_path": file_path,
+            }
+        except SlackApiError as e:
+            error_msg = e.response["error"]
+            print(f"[Slack] Error uploading file: {error_msg}")
+            return {"success": False, "error": error_msg}
+        except Exception as e:
+            print(f"[Slack] Unexpected error uploading file: {e}")
+            return {"success": False, "error": str(e)}
+
     async def _get_username(self, user_id: str) -> str:
         """Get username from user ID, with caching to avoid excessive API calls.
 

adapters/telegram/adapter.py

@@ -306,6 +306,58 @@ class TelegramAdapter(BaseAdapter):
         except TelegramError as e:
             print(f"[Telegram] Error sending typing indicator: {e}")
 
+    async def send_file(
+        self,
+        channel_id: str,
+        file_path: str,
+        caption: Optional[str] = None,
+        thread_id: Optional[str] = None
+    ) -> Dict[str, Any]:
+        """Send a file (image or document) to Telegram."""
+        if not self.bot:
+            return {"success": False, "error": "Bot not started"}
+
+        try:
+            from pathlib import Path
+            path = Path(file_path)
+
+            if not path.exists():
+                return {"success": False, "error": f"File not found: {file_path}"}
+
+            chat_id = int(channel_id)
+            reply_to = int(thread_id) if thread_id else None
+            ext = path.suffix.lower()
+
+            # Send as photo for images, document for others
+            if ext in [".png", ".jpg", ".jpeg", ".gif", ".webp"]:
+                with open(path, "rb") as photo:
+                    sent = await self.bot.send_photo(
+                        chat_id=chat_id,
+                        photo=photo,
+                        caption=caption,
+                        reply_to_message_id=reply_to,
+                    )
+            else:
+                with open(path, "rb") as document:
+                    sent = await self.bot.send_document(
+                        chat_id=chat_id,
+                        document=document,
+                        caption=caption,
+                        reply_to_message_id=reply_to,
+                    )
+
+            return {
+                "success": True,
+                "message_id": sent.message_id,
+                "file_path": file_path,
+            }
+        except TelegramError as e:
+            print(f"[Telegram] Error sending file: {e}")
+            return {"success": False, "error": str(e)}
+        except Exception as e:
+            print(f"[Telegram] Unexpected error sending file: {e}")
+            return {"success": False, "error": str(e)}
+
     async def health_check(self) -> Dict[str, Any]:
         """Perform health check."""
         base_health = await super().health_check()

agent_registry.py

@@ -0,0 +1,76 @@
+"""Agent Registry - Thread-safe global singleton for MCP tool access.
+
+MCP tools are module-level functions that cannot access the Agent instance
+directly. This registry provides a thread-safe bridge so that tools like
+delegate_task can call Agent.delegate() without circular imports.
+
+Usage:
+    # At bot startup (bot_runner.py):
+    from agent_registry import register_agent
+    agent = Agent(...)
+    register_agent(agent)
+
+    # In MCP tools (mcp_tools.py):
+    from agent_registry import get_agent
+    agent = get_agent()
+    if agent:
+        result = agent.delegate(task, specialist_prompt)
+"""
+
+import threading
+from typing import Optional, TYPE_CHECKING
+
+if TYPE_CHECKING:
+    from agent import Agent
+
+# Module-level singleton state
+_agent: Optional['Agent'] = None
+_lock = threading.Lock()
+
+
+def register_agent(agent: 'Agent') -> None:
+    """Register the main Agent instance for MCP tool access.
+
+    Must be called exactly once at bot startup, after Agent is initialized.
+    Thread-safe.
+
+    Args:
+        agent: The main Agent instance (not a sub-agent).
+
+    Raises:
+        ValueError: If agent is None or is a sub-agent.
+    """
+    global _agent
+
+    if agent is None:
+        raise ValueError("Cannot register None as the main agent")
+    if getattr(agent, 'is_sub_agent', False):
+        raise ValueError("Cannot register a sub-agent as the main agent")
+
+    with _lock:
+        _agent = agent
+        print(f"[AgentRegistry] Main agent registered (provider={agent.llm.provider})")
+
+
+def get_agent() -> Optional['Agent']:
+    """Get the registered main Agent instance.
+
+    Thread-safe. Returns None if no agent has been registered yet.
+
+    Returns:
+        The main Agent instance, or None.
+    """
+    with _lock:
+        return _agent
+
+
+def clear_agent() -> None:
+    """Clear the registered agent (for testing or shutdown).
+
+    Thread-safe.
+    """
+    global _agent
+
+    with _lock:
+        _agent = None
+        print("[AgentRegistry] Agent registry cleared")

bot_runner.py

@@ -26,6 +26,7 @@ from adapters.runtime import AdapterRuntime
 from adapters.slack.adapter import SlackAdapter
 from adapters.telegram.adapter import TelegramAdapter
 from agent import Agent
+from agent_registry import register_agent
 from config.config_loader import ConfigLoader
 from google_tools.oauth_manager import GoogleOAuthManager
 from scheduled_tasks import TaskScheduler
@@ -79,6 +80,9 @@ class BotRunner:
         )
         print("[Setup] Agent initialized")
 
+        # Register agent in global registry for MCP tool access (delegate_task)
+        register_agent(self.agent)
+
         self.runtime = AdapterRuntime(self.agent)
 
         enabled_count = sum(

config/excalidraw_mcp.yaml

@@ -0,0 +1,6 @@
+excalidraw_mcp:
+  enabled: true
+  output_dir: "downloads/diagrams/excalidraw"  # Default location; bot can save elsewhere if requested
+  default_export_type: "png"  # Options: png, svg
+  canvas_width: 1920
+  canvas_height: 1080

config/mermaid_mcp.yaml

@@ -0,0 +1,5 @@
+mermaid_mcp:
+  enabled: true
+  output_dir: "downloads/diagrams/mermaid"  # Default location; bot can save elsewhere if requested
+  default_format: "png"  # Options: png, svg, pdf
+  theme: "default"  # Options: default, dark, forest, neutral

mcp_servers/excalidraw/excalidraw_mcp.py

@@ -0,0 +1,89 @@
+"""Excalidraw MCP Server Integration.
+
+Manages the external excalidraw-mcp server process for hand-drawn style diagram generation.
+
+Architecture:
+    Garvis → (stdio) → excalidraw-mcp (Node.js) → Canvas API → PNG/SVG images
+"""
+
+import os
+from pathlib import Path
+from typing import Any, Dict, List
+import yaml
+
+_CONFIG_FILE = Path("config/excalidraw_mcp.yaml")
+
+def _load_config() -> Dict[str, Any]:
+    """Load Excalidraw MCP configuration from YAML and env vars."""
+    config = {}
+    if _CONFIG_FILE.exists():
+        try:
+            with open(_CONFIG_FILE, encoding="utf-8") as f:
+                config = yaml.safe_load(f) or {}
+        except Exception:
+            pass  # Use defaults if config fails to load
+
+    excalidraw = config.get("excalidraw_mcp", {})
+
+    # Apply env var overrides
+    if os.getenv("EXCALIDRAW_ENABLED"):
+        excalidraw["enabled"] = os.getenv("EXCALIDRAW_ENABLED").lower() in ("true", "1")
+    if os.getenv("EXCALIDRAW_OUTPUT_DIR"):
+        excalidraw["output_dir"] = os.getenv("EXCALIDRAW_OUTPUT_DIR")
+    if os.getenv("EXCALIDRAW_DEFAULT_EXPORT"):
+        excalidraw["default_export_type"] = os.getenv("EXCALIDRAW_DEFAULT_EXPORT")
+
+    # Set defaults if not configured
+    excalidraw.setdefault("enabled", True)
+    excalidraw.setdefault("output_dir", "downloads/diagrams/excalidraw")
+    excalidraw.setdefault("default_export_type", "png")
+    excalidraw.setdefault("canvas_width", 1920)
+    excalidraw.setdefault("canvas_height", 1080)
+
+    return excalidraw
+
+def is_excalidraw_enabled() -> bool:
+    """Check if Excalidraw MCP integration is enabled."""
+    config = _load_config()
+    return config.get("enabled", True)
+
+def get_excalidraw_server_config() -> Dict[str, Any]:
+    """Build the MCP server configuration for Agent SDK registration.
+
+    Returns:
+        Dict with command, args, and env for subprocess execution
+    """
+    config = _load_config()
+    output_dir = config.get("output_dir", "downloads/diagrams/excalidraw")
+
+    # Ensure output directory exists
+    Path(output_dir).mkdir(parents=True, exist_ok=True)
+
+    # Build environment variables for the MCP server
+    env = {
+        "PATH": os.environ.get("PATH", ""),
+        "HOME": os.environ.get("HOME", os.environ.get("USERPROFILE", "")),
+        "APPDATA": os.environ.get("APPDATA", ""),
+        "TEMP": os.environ.get("TEMP", os.environ.get("TMP", "")),
+    }
+
+    # Add config as env vars for the server
+    env["EXCALIDRAW_OUTPUT_DIR"] = str(Path(output_dir).absolute())
+    env["EXCALIDRAW_DEFAULT_EXPORT"] = config.get("default_export_type", "png")
+    env["EXCALIDRAW_CANVAS_WIDTH"] = str(config.get("canvas_width", 1920))
+    env["EXCALIDRAW_CANVAS_HEIGHT"] = str(config.get("canvas_height", 1080))
+
+    return {
+        "command": "npx",
+        "args": ["-y", "excalidraw-mcp"],
+        "env": env,
+    }
+
+# Tool names exposed by excalidraw-mcp
+# Based on excalidraw-mcp documentation
+EXCALIDRAW_TOOLS: List[str] = [
+    "create_diagram",      # Create new Excalidraw diagram
+    "add_element",         # Add shape/element to diagram
+    "export_diagram",      # Export to PNG/SVG
+    "list_diagrams",       # List saved diagrams
+]

mcp_servers/mermaid/mermaid_mcp.py

@@ -0,0 +1,86 @@
+"""Mermaid MCP Server Integration.
+
+Manages the external @peng-shawn/mermaid-mcp-server process for diagram generation.
+
+Architecture:
+    Garvis → (stdio) → mermaid-mcp-server (Node.js) → Puppeteer → PNG images
+"""
+
+import os
+from pathlib import Path
+from typing import Any, Dict, List
+import yaml
+
+_CONFIG_FILE = Path("config/mermaid_mcp.yaml")
+
+def _load_config() -> Dict[str, Any]:
+    """Load Mermaid MCP configuration from YAML and env vars."""
+    config = {}
+    if _CONFIG_FILE.exists():
+        try:
+            with open(_CONFIG_FILE, encoding="utf-8") as f:
+                config = yaml.safe_load(f) or {}
+        except Exception:
+            pass  # Use defaults if config fails to load
+
+    mermaid = config.get("mermaid_mcp", {})
+
+    # Apply env var overrides
+    if os.getenv("MERMAID_ENABLED"):
+        mermaid["enabled"] = os.getenv("MERMAID_ENABLED").lower() in ("true", "1")
+    if os.getenv("MERMAID_OUTPUT_DIR"):
+        mermaid["output_dir"] = os.getenv("MERMAID_OUTPUT_DIR")
+    if os.getenv("MERMAID_DEFAULT_FORMAT"):
+        mermaid["default_format"] = os.getenv("MERMAID_DEFAULT_FORMAT")
+    if os.getenv("MERMAID_THEME"):
+        mermaid["theme"] = os.getenv("MERMAID_THEME")
+
+    # Set defaults if not configured
+    mermaid.setdefault("enabled", True)
+    mermaid.setdefault("output_dir", "downloads/diagrams/mermaid")
+    mermaid.setdefault("default_format", "png")
+    mermaid.setdefault("theme", "default")
+
+    return mermaid
+
+def is_mermaid_enabled() -> bool:
+    """Check if Mermaid MCP integration is enabled."""
+    config = _load_config()
+    return config.get("enabled", True)
+
+def get_mermaid_server_config() -> Dict[str, Any]:
+    """Build the MCP server configuration for Agent SDK registration.
+
+    Returns:
+        Dict with command, args, and env for subprocess execution
+    """
+    config = _load_config()
+    output_dir = config.get("output_dir", "downloads/diagrams/mermaid")
+
+    # Ensure output directory exists
+    Path(output_dir).mkdir(parents=True, exist_ok=True)
+
+    # Build environment variables for the MCP server
+    env = {
+        "PATH": os.environ.get("PATH", ""),
+        "HOME": os.environ.get("HOME", os.environ.get("USERPROFILE", "")),
+        "APPDATA": os.environ.get("APPDATA", ""),
+        "TEMP": os.environ.get("TEMP", os.environ.get("TMP", "")),
+    }
+
+    # Add config as env vars for the server
+    env["MERMAID_OUTPUT_DIR"] = str(Path(output_dir).absolute())
+    env["MERMAID_DEFAULT_FORMAT"] = config.get("default_format", "png")
+    env["MERMAID_THEME"] = config.get("theme", "default")
+
+    return {
+        "command": "npx",
+        "args": ["-y", "@peng-shawn/mermaid-mcp-server"],
+        "env": env,
+    }
+
+# Tool names exposed by mermaid-mcp-server
+# Based on @peng-shawn/mermaid-mcp-server documentation
+MERMAID_TOOLS: List[str] = [
+    "render_mermaid",  # Main tool: convert Mermaid syntax to PNG
+]

mcp_tools.py

@@ -10,6 +10,7 @@ import subprocess
 from typing import Any, Dict, List, Optional
 from urllib.parse import urlparse
 from datetime import datetime
+import threading
 from claude_agent_sdk import tool, create_sdk_mcp_server
 import httpx
 from bs4 import BeautifulSoup
@@ -21,9 +22,16 @@ try:
 except ImportError:
     MEMORY_AVAILABLE = False
 
+# Import agent registry for delegate_task tool
+try:
+    from agent_registry import get_agent
+    AGENT_REGISTRY_AVAILABLE = True
+except ImportError:
+    AGENT_REGISTRY_AVAILABLE = False
+
 
 # Maximum characters of tool output to return (prevents token explosion)
-_MAX_TOOL_OUTPUT = 5000
+_MAX_TOOL_OUTPUT = 5000  # Restored for complex diagram generation
 
 # Maximum page size for web fetching (500KB)
 _MAX_WEB_PAGE_SIZE = 500_000
@@ -188,7 +196,7 @@ def _is_safe_url(url: str) -> bool:
     },
 )
 async def read_file_tool(args: Dict[str, Any]) -> Dict[str, Any]:
-    """Read and return file contents."""
+    """Read and return file contents with auto-retry for PDFs."""
     file_path = args["file_path"]
     path = Path(file_path)
 
@@ -198,6 +206,136 @@ async def read_file_tool(args: Dict[str, Any]) -> Dict[str, Any]:
             "isError": True
         }
 
+    # Check if it's a PDF
+    is_pdf = path.suffix.lower() == ".pdf"
+
+    if is_pdf:
+        # Try reading PDF with multiple methods
+        for attempt, method in enumerate(["pypdf", "pdfplumber", "pdfminer"], 1):
+            try:
+                if method == "pypdf":
+                    try:
+                        from pypdf import PdfReader
+                    except ImportError:
+                        continue  # Try next method
+
+                    reader = PdfReader(path)
+
+                    # Check if actually password-protected
+                    if reader.is_encrypted:
+                        # Try with empty password first (some PDFs are "encrypted" with no password)
+                        try:
+                            reader.decrypt("")
+                        except Exception:
+                            return {
+                                "content": [{"type": "text", "text": f"PDF is password-protected and cannot be read without the password."}],
+                                "isError": True
+                            }
+
+                    # Extract text from all pages with early truncation
+                    text_parts = []
+                    total_length = 0
+                    truncated = False
+
+                    for i, page in enumerate(reader.pages, 1):
+                        page_text = page.extract_text()
+                        if page_text.strip():
+                            page_section = f"--- Page {i} ---\n{page_text}"
+
+                            # Check if adding this page would exceed limit
+                            if total_length + len(page_section) + 2 > _MAX_TOOL_OUTPUT:  # +2 for "\n\n"
+                                # Add partial page if there's room
+                                remaining = _MAX_TOOL_OUTPUT - total_length - 2
+                                if remaining > 100:  # Only add if we can fit meaningful content
+                                    text_parts.append(page_section[:remaining])
+                                truncated = True
+                                break
+
+                            text_parts.append(page_section)
+                            total_length += len(page_section) + 2
+
+                    content = "\n\n".join(text_parts)
+                    if truncated:
+                        content += f"\n... (PDF truncated - showing first {len(text_parts)} of {len(reader.pages)} pages)"
+
+                    return {
+                        "content": [{"type": "text", "text": f"Content of {file_path} ({len(reader.pages)} pages):\n\n{content}"}]
+                    }
+
+                elif method == "pdfplumber":
+                    try:
+                        import pdfplumber
+                    except ImportError:
+                        continue
+
+                    with pdfplumber.open(path) as pdf:
+                        text_parts = []
+                        total_length = 0
+                        truncated = False
+                        total_pages = len(pdf.pages)
+
+                        for i, page in enumerate(pdf.pages, 1):
+                            page_text = page.extract_text()
+                            if page_text and page_text.strip():
+                                page_section = f"--- Page {i} ---\n{page_text}"
+
+                                # Check if adding this page would exceed limit
+                                if total_length + len(page_section) + 2 > _MAX_TOOL_OUTPUT:
+                                    remaining = _MAX_TOOL_OUTPUT - total_length - 2
+                                    if remaining > 100:
+                                        text_parts.append(page_section[:remaining])
+                                    truncated = True
+                                    break
+
+                                text_parts.append(page_section)
+                                total_length += len(page_section) + 2
+
+                        content = "\n\n".join(text_parts)
+                        if truncated:
+                            content += f"\n... (PDF truncated - showing first {len(text_parts)} of {total_pages} pages)"
+
+                        return {
+                            "content": [{"type": "text", "text": f"Content of {file_path} ({total_pages} pages):\n\n{content}"}]
+                        }
+
+                elif method == "pdfminer":
+                    try:
+                        from pdfminer.high_level import extract_text as pdfminer_extract
+                    except ImportError:
+                        continue
+
+                    content = pdfminer_extract(path)
+                    if len(content) > _MAX_TOOL_OUTPUT:
+                        content = content[:_MAX_TOOL_OUTPUT] + "\n... (PDF truncated)"
+
+                    return {
+                        "content": [{"type": "text", "text": f"Content of {file_path}:\n\n{content}"}]
+                    }
+
+            except Exception as e:
+                # If this is the last attempt, return the error
+                if attempt == 3:
+                    error_msg = str(e).lower()
+                    if "password" in error_msg or "encrypted" in error_msg:
+                        return {
+                            "content": [{"type": "text", "text": f"PDF appears to be password-protected: {str(e)}"}],
+                            "isError": True
+                        }
+                    else:
+                        return {
+                            "content": [{"type": "text", "text": f"Error reading PDF after trying multiple methods: {str(e)}. The PDF might be corrupted or use an unsupported format."}],
+                            "isError": True
+                        }
+                # Otherwise, continue to next method
+                continue
+
+        # If we get here, no PDF library is installed
+        return {
+            "content": [{"type": "text", "text": f"Cannot read PDF: No PDF library installed. Install with: pip install pypdf pdfplumber"}],
+            "isError": True
+        }
+
+    # Non-PDF files: try reading as text
     try:
         content = path.read_text(encoding="utf-8")
         if len(content) > _MAX_TOOL_OUTPUT:
@@ -206,6 +344,12 @@ async def read_file_tool(args: Dict[str, Any]) -> Dict[str, Any]:
         return {
             "content": [{"type": "text", "text": f"Content of {file_path}:\n\n{content}"}]
         }
+    except UnicodeDecodeError:
+        # Binary file that's not a PDF
+        return {
+            "content": [{"type": "text", "text": f"Error: {file_path} appears to be a binary file. Only text files and PDFs are supported."}],
+            "isError": True
+        }
     except Exception as e:
         return {
             "content": [{"type": "text", "text": f"Error reading file: {str(e)}"}],
@@ -1778,6 +1922,129 @@ async def gitea_get_tree_tool(args: Dict[str, Any]) -> Dict[str, Any]:
         }
 
 
+
+
+# ============================================
+# Sub-Agent Delegation Tool (MCP Bridge)
+# ============================================
+
+@tool(
+    name="delegate_task",
+    description=(
+        "Delegate a task to a specialist sub-agent. The sub-agent runs in a separate "
+        "thread with its own conversation context but shares the memory workspace. "
+        "Use this to parallelize work (e.g., creating multiple diagrams, researching "
+        "multiple topics). Each sub-agent gets a specialist prompt defining its role. "
+        "Returns the sub-agent's final response text."
+    ),
+    input_schema={
+        "task": str,
+        "specialist_prompt": str,
+        "agent_id": str,
+    },
+)
+async def delegate_task_tool(args: Dict[str, Any]) -> Dict[str, Any]:
+    """Delegate a task to a specialist sub-agent via the main Agent.
+
+    This MCP tool bridges the gap between the Agent SDK subprocess (claude.exe)
+    and the in-process Agent.delegate() method. It retrieves the main Agent
+    from the global registry and calls delegate() synchronously.
+
+    Thread-safe: Agent.delegate() uses Agent._chat_lock internally, and
+    MemorySystem.write_memory() uses _write_lock for file operations.
+    """
+    task = args.get("task", "")
+    specialist_prompt = args.get("specialist_prompt", "")
+    agent_id = args.get("agent_id", "")
+
+    # Validate required fields
+    if not task:
+        return {
+            "content": [{"type": "text", "text": "Error: 'task' is required"}],
+            "isError": True,
+        }
+    if not specialist_prompt:
+        return {
+            "content": [{
+                "type": "text",
+                "text": "Error: 'specialist_prompt' is required (defines the sub-agent role)",
+            }],
+            "isError": True,
+        }
+
+    # Check agent registry availability
+    if not AGENT_REGISTRY_AVAILABLE:
+        return {
+            "content": [{
+                "type": "text",
+                "text": "Error: agent_registry module not available. Cannot delegate tasks.",
+            }],
+            "isError": True,
+        }
+
+    # Get the main agent from the global registry
+    agent = get_agent()
+    if agent is None:
+        return {
+            "content": [{
+                "type": "text",
+                "text": (
+                    "Error: No agent registered. The bot may still be starting up, "
+                    "or agent_registry.register_agent() was not called at startup."
+                ),
+            }],
+            "isError": True,
+        }
+
+    # Generate agent_id if not provided
+    if not agent_id:
+        agent_id = f"sub_{threading.current_thread().name}_{id(args)}"
+
+    try:
+        # Run delegate in a thread to avoid blocking the async event loop.
+        # Agent.delegate() is synchronous (calls sub_agent.chat() which holds _chat_lock).
+        import asyncio
+        loop = asyncio.get_event_loop()
+        result = await loop.run_in_executor(
+            None,  # Use default thread pool
+            lambda: agent.delegate(
+                task=task,
+                specialist_prompt=specialist_prompt,
+                username="default",
+                agent_id=agent_id,
+                max_retries=1,
+            ),
+        )
+
+        # Truncate result if too large
+        if len(result) > _MAX_TOOL_OUTPUT:
+            result = result[:_MAX_TOOL_OUTPUT] + "\n... (sub-agent output truncated)"
+
+        return {
+            "content": [{
+                "type": "text",
+                "text": f"[Sub-agent {agent_id}] Task completed:\n\n{result}",
+            }],
+        }
+
+    except TimeoutError:
+        return {
+            "content": [{
+                "type": "text",
+                "text": f"Error: Sub-agent '{agent_id}' timed out. Task may be too complex.",
+            }],
+            "isError": True,
+        }
+    except Exception as e:
+        return {
+            "content": [{
+                "type": "text",
+                "text": f"Error delegating to sub-agent '{agent_id}': {type(e).__name__}: {str(e)}",
+            }],
+            "isError": True,
+        }
+
+
 # Create the MCP server with all tools
 file_system_server = create_sdk_mcp_server(
     name="file_system",
@@ -1817,5 +2084,7 @@ file_system_server = create_sdk_mcp_server(
         gitea_list_files_tool,
         gitea_search_code_tool,
         gitea_get_tree_tool,
+        # Sub-agent delegation
+        delegate_task_tool,
     ]
 )

memory_system.py

@@ -6,6 +6,7 @@ Inspired by OpenClaw's memory implementation but simplified.
 
 import hashlib
 import sqlite3
+import threading
 import time
 from datetime import datetime
 from pathlib import Path
@@ -84,6 +85,11 @@ class MemorySystem:
         self.db = sqlite3.connect(str(self.db_path), check_same_thread=False)
         self.db.row_factory = sqlite3.Row
 
+        # Write lock for concurrent sub-agent access to shared memory files.
+        # Prevents race conditions when multiple sub-agents write to the same
+        # daily log or MEMORY.md simultaneously.
+        self._write_lock = threading.Lock()
+
         self._init_schema()
         self._init_special_files()
 
@@ -575,7 +581,8 @@ class MemorySystem:
         return compact
 
     def write_memory(self, content: str, daily: bool = True) -> None:
-        """Write to memory file."""
+        """Write to memory file. Thread-safe via _write_lock."""
+        with self._write_lock:
             if daily:
                 today = datetime.now().strftime("%Y-%m-%d")
                 file_path = self.memory_dir / f"{today}.md"
@@ -591,7 +598,8 @@ class MemorySystem:
             print(f"Written to {file_path.name}")
 
     def update_soul(self, content: str, append: bool = False) -> None:
-        """Update SOUL.md (agent personality)."""
+        """Update SOUL.md (agent personality). Thread-safe via _write_lock."""
+        with self._write_lock:
             soul_file = self.workspace_dir / "SOUL.md"
 
             if append and soul_file.exists():

sub_agent_manager.py

@@ -0,0 +1,197 @@
+"""Sub-Agent Manager - Monitors and manages sub-agent lifecycle.
+
+Handles:
+- Sub-agent spawning and tracking
+- Progress monitoring and hang detection
+- Automatic cleanup and restart on timeout
+"""
+
+import time
+import threading
+from typing import Dict, Optional, Any
+from dataclasses import dataclass
+import logging
+
+logger = logging.getLogger(__name__)
+
+
+@dataclass
+class SubAgentState:
+    """Track state of a running sub-agent."""
+    agent_id: str
+    task_description: str
+    started_at: float
+    last_activity: float
+    is_complete: bool = False
+    result: Optional[str] = None
+    error: Optional[str] = None
+
+
+class SubAgentManager:
+    """Manages sub-agent lifecycle with hang detection and auto-restart."""
+
+    def __init__(self, timeout_seconds: int = 300):  # 5 minutes default
+        """Initialize manager.
+
+        Args:
+            timeout_seconds: Maximum time without progress before killing sub-agent
+        """
+        self.timeout_seconds = timeout_seconds
+        self.sub_agents: Dict[str, SubAgentState] = {}
+        self._lock = threading.Lock()
+        self._watchdog_thread: Optional[threading.Thread] = None
+        self._watchdog_running = False
+
+    def start_watchdog(self) -> None:
+        """Start the watchdog thread that monitors for hung sub-agents."""
+        if self._watchdog_running:
+            return
+
+        self._watchdog_running = True
+        self._watchdog_thread = threading.Thread(
+            target=self._watchdog_loop,
+            daemon=True,
+            name="SubAgentWatchdog"
+        )
+        self._watchdog_thread.start()
+        logger.info("[SubAgentManager] Watchdog started (timeout: %ds)", self.timeout_seconds)
+
+    def stop_watchdog(self) -> None:
+        """Stop the watchdog thread."""
+        self._watchdog_running = False
+        if self._watchdog_thread:
+            self._watchdog_thread.join(timeout=2)
+
+    def register_sub_agent(
+        self,
+        agent_id: str,
+        task_description: str
+    ) -> None:
+        """Register a new sub-agent for monitoring."""
+        with self._lock:
+            now = time.time()
+            self.sub_agents[agent_id] = SubAgentState(
+                agent_id=agent_id,
+                task_description=task_description,
+                started_at=now,
+                last_activity=now
+            )
+            logger.info("[SubAgentManager] Registered sub-agent: %s - %s", agent_id, task_description)
+
+    def update_activity(self, agent_id: str) -> None:
+        """Update last activity timestamp for a sub-agent."""
+        with self._lock:
+            if agent_id in self.sub_agents:
+                self.sub_agents[agent_id].last_activity = time.time()
+
+    def mark_complete(
+        self,
+        agent_id: str,
+        result: Optional[str] = None,
+        error: Optional[str] = None
+    ) -> None:
+        """Mark a sub-agent as complete."""
+        with self._lock:
+            if agent_id in self.sub_agents:
+                self.sub_agents[agent_id].is_complete = True
+                self.sub_agents[agent_id].result = result
+                self.sub_agents[agent_id].error = error
+                logger.info("[SubAgentManager] Sub-agent completed: %s (success=%s)",
+                           agent_id, error is None)
+
+    def get_hung_agents(self) -> list:
+        """Get list of sub-agent IDs that appear to be hung."""
+        now = time.time()
+        hung = []
+
+        with self._lock:
+            for agent_id, state in self.sub_agents.items():
+                if state.is_complete:
+                    continue
+
+                time_since_activity = now - state.last_activity
+                if time_since_activity > self.timeout_seconds:
+                    hung.append(agent_id)
+                    logger.warning(
+                        "[SubAgentManager] Sub-agent appears hung: %s - %s (no activity for %.1fs)",
+                        agent_id, state.task_description, time_since_activity
+                    )
+
+        return hung
+
+    def cleanup_agent(self, agent_id: str) -> None:
+        """Clean up a hung sub-agent."""
+        with self._lock:
+            if agent_id in self.sub_agents:
+                state = self.sub_agents[agent_id]
+                logger.error(
+                    "[SubAgentManager] Cleaning up hung sub-agent: %s - %s (hung for %.1fs)",
+                    agent_id,
+                    state.task_description,
+                    time.time() - state.last_activity
+                )
+
+                # Mark as failed
+                state.is_complete = True
+                state.error = f"Timeout: No progress for {self.timeout_seconds}s"
+
+    def _watchdog_loop(self) -> None:
+        """Watchdog loop that runs in background thread."""
+        while self._watchdog_running:
+            try:
+                hung_agents = self.get_hung_agents()
+                for agent_id in hung_agents:
+                    self.cleanup_agent(agent_id)
+
+                # Check every 30 seconds
+                time.sleep(30)
+
+            except Exception as e:
+                logger.error("[SubAgentManager] Watchdog error: %s", e)
+                time.sleep(30)
+
+    def get_status(self) -> Dict[str, Any]:
+        """Get current status of all sub-agents."""
+        now = time.time()
+        status = {
+            "total": len(self.sub_agents),
+            "complete": 0,
+            "running": 0,
+            "hung": 0,
+            "agents": []
+        }
+
+        with self._lock:
+            for agent_id, state in self.sub_agents.items():
+                agent_status = {
+                    "id": agent_id,
+                    "task": state.task_description,
+                    "runtime": now - state.started_at,
+                    "idle_time": now - state.last_activity,
+                    "complete": state.is_complete,
+                    "has_error": state.error is not None
+                }
+
+                if state.is_complete:
+                    status["complete"] += 1
+                elif (now - state.last_activity) > self.timeout_seconds:
+                    status["hung"] += 1
+                else:
+                    status["running"] += 1
+
+                status["agents"].append(agent_status)
+
+        return status
+
+    def clear_completed(self) -> None:
+        """Remove completed sub-agents from tracking."""
+        with self._lock:
+            completed = [
+                agent_id for agent_id, state in self.sub_agents.items()
+                if state.is_complete
+            ]
+            for agent_id in completed:
+                del self.sub_agents[agent_id]
+
+            if completed:
+                logger.info("[SubAgentManager] Cleared %d completed sub-agents", len(completed))