System Information MCP Server

Instructions

Implementation Reference

• src/system_info_mcp/server.py:68-79 (handler)

  MCP tool handler for get_process_list_tool, decorated with @app.tool() which registers the tool and defines input schema via type hints and docstring.
  @app.tool() def get_process_list_tool( limit: int = 50, sort_by: str = "cpu", filter_name: Optional[str] = None ) -> Dict[str, Any]: """Retrieve list of running processes. Args: limit: Maximum number of processes to return (default: 50) sort_by: Sort criteria - cpu, memory, name, pid (default: cpu) filter_name: Filter processes by name pattern """ return get_process_list(limit=limit, sort_by=sort_by, filter_name=filter_name)
• src/system_info_mcp/tools.py:259-347 (helper)

  Core implementation logic for retrieving, filtering, sorting, and formatting the process list using psutil.
  @cache_result("process_list", ttl=2) def get_process_list( limit: int = 50, sort_by: str = "cpu", filter_name: Optional[str] = None ) -> Dict[str, Any]: """Retrieve list of running processes.""" try: # Validate parameters if limit <= 0: raise ValueError("Limit must be a positive number") limit = min(limit, config.max_processes) valid_sort_keys = ["cpu", "memory", "name", "pid"] if sort_by not in valid_sort_keys: raise ValueError(f"sort_by must be one of: {valid_sort_keys}") processes = [] # Get all processes for proc in psutil.process_iter( [ "pid", "name", "username", "status", "cpu_percent", "memory_percent", "memory_info", "create_time", "cmdline", ] ): try: proc_info = proc.info # Filter by name if specified if filter_name and filter_name.lower() not in proc_info["name"].lower(): continue # Get memory RSS memory_rss = 0 if proc_info.get("memory_info"): memory_rss = proc_info["memory_info"].rss # Filter and format command line cmdline = filter_sensitive_cmdline(proc_info.get("cmdline") or []) process_data = { "pid": proc_info["pid"], "name": proc_info["name"] or "Unknown", "username": proc_info.get("username", "Unknown"), "status": proc_info.get("status", "unknown"), "cpu_percent": round( safe_float(proc_info.get("cpu_percent", 0)), 1 ), "memory_percent": round( safe_float(proc_info.get("memory_percent", 0)), 1 ), "memory_rss": memory_rss, "memory_rss_mb": bytes_to_mb(memory_rss), "create_time": timestamp_to_iso(proc_info.get("create_time", 0)), "cmdline": cmdline, } processes.append(process_data) except (psutil.NoSuchProcess, psutil.AccessDenied, psutil.ZombieProcess): # Process may have terminated or we don't have permission continue # Sort processes reverse_sort = True # Most metrics should be sorted in descending order if sort_by == "cpu": processes.sort(key=lambda p: p["cpu_percent"], reverse=reverse_sort) elif sort_by == "memory": processes.sort(key=lambda p: p["memory_percent"], reverse=reverse_sort) elif sort_by == "name": processes.sort(key=lambda p: p["name"].lower(), reverse=False) elif sort_by == "pid": processes.sort(key=lambda p: p["pid"], reverse=False) # Apply limit limited_processes = processes[:limit] return {"processes": limited_processes, "total_processes": len(processes)} except Exception as e: logger.error(f"Error getting process list: {e}") raise