System Information MCP Server

Instructions

Implementation Reference

• src/sysinfo/server.py:172-189 (handler)

  MCP tool handler for get_running_processes. Wraps the collector function, formats output as ToolResult with markdown sections.

  @mcp.tool
  def get_running_processes() -> ToolResult:
      """Get list of running processes with resource usage and executable paths.
      
      Shows top processes by CPU/memory usage with PIDs, names, and executable paths.
      Essential for performance analysis, troubleshooting resource issues, and security auditing.
      """
      info_sections = []
      info_sections.append("# Running Processes")
      info_sections.append(f"*Generated: {datetime.now().strftime('%Y-%m-%d %H:%M:%S')}*\n")
      
      try:
          from .collectors import get_running_processes as get_processes_data
          info_sections.extend(get_processes_data())
      except Exception as e:
          info_sections.append(f"⚠️ **Process detection error**: {str(e)}")
      
      return text_response("\n".join(info_sections))

• src/sysinfo/collectors.py:817-882 (helper)

  Core helper function that iterates over processes using psutil, collects CPU/memory usage, sorts top processes, and formats as markdown table with summary.

  def get_running_processes() -> List[str]:
      """Get list of running processes with resource usage"""
      info = []
      info.append("## ⚙️ Running Processes")
      
      try:
          # Get all processes and sort by CPU usage
          processes = []
          for proc in psutil.process_iter(['pid', 'name', 'cpu_percent', 'memory_percent', 'exe', 'cmdline']):
              try:
                  pinfo = proc.info
                  if pinfo['name'] and pinfo['name'] != '':
                      # Get CPU percent (this call triggers measurement)
                      cpu_percent = proc.cpu_percent()
                      pinfo['cpu_percent'] = cpu_percent
                      processes.append(pinfo)
              except (psutil.NoSuchProcess, psutil.AccessDenied, psutil.ZombieProcess):
                  continue
          
          # Sort by CPU usage, then memory usage
          processes.sort(key=lambda x: (x.get('cpu_percent', 0), x.get('memory_percent', 0)), reverse=True)
          
          # Display top 20 processes
          info.append(f"\n### Top Processes (by CPU/Memory usage)")
          info.append("| PID | Name | CPU% | Memory% | Path |")
          info.append("|-----|------|------|---------|------|")
          
          count = 0
          for proc in processes:
              if count >= 20:
                  break
                  
              pid = proc.get('pid', 'N/A')
              name = proc.get('name', 'Unknown')[:20]  # Truncate long names
              cpu = proc.get('cpu_percent', 0)
              memory = proc.get('memory_percent', 0)
              
              # Get executable path
              exe_path = proc.get('exe', '')
              if not exe_path and proc.get('cmdline'):
                  # Fallback to first command line argument
                  cmdline = proc.get('cmdline', [])
                  if cmdline:
                      exe_path = cmdline[0]
              
              # Truncate path for display
              if exe_path:
                  if len(exe_path) > 40:
                      exe_path = "..." + exe_path[-37:]
              else:
                  exe_path = "N/A"
              
              # Only show processes with some activity or important system processes
              if cpu > 0.1 or memory > 0.5 or name.lower() in ['kernel_task', 'systemd', 'init', 'launchd']:
                  info.append(f"| {pid} | {name} | {cpu:.1f}% | {memory:.1f}% | {exe_path} |")
                  count += 1
          
          # Add process summary
          total_processes = len(processes)
          active_processes = len([p for p in processes if p.get('cpu_percent', 0) > 0])
          info.append(f"\n**Summary**: {total_processes} total processes, {active_processes} active")
          
      except Exception as e:
          info.append(f"⚠️ **Error collecting process information**: {str(e)}")
      
      return info