Build Unblocker MCP

import psutil import time import typing as t import json import sys from datetime import datetime from mcp.server.fastmcp import FastMCP from .config import DEFAULT_PROCESSES, Settings mcp = FastMCP( name="Build Unblocker", description="Terminate hung Windows build executables so Cursor can unblock itself." ) def is_process_idle(proc: psutil.Process, idle_seconds: int) -> bool: """Checks if a process is idle based on CPU usage and age.""" try: # Check CPU usage over a 1-second interval cpu_percent = proc.cpu_percent(interval=1.0) if cpu_percent >= 1.0: return False # Check process age create_time = proc.create_time() process_age = time.time() - create_time if process_age < idle_seconds: return False return True except (psutil.NoSuchProcess, psutil.AccessDenied, psutil.ZombieProcess): # Process may have exited or access denied, treat as not idle for safety return False @mcp.tool(name="unblock_build", description="Kill build executables idle > idle_seconds.") def unblock_build(idle_seconds: int = 90, process_names: t.List[str] | None = None, dry_run: bool = False) -> dict: """ Terminates hung build executables that are idle for a specified duration. Args: idle_seconds: The duration in seconds a process must be idle to be considered hung. process_names: A list of process names to monitor. Defaults to DEFAULT_PROCESSES. dry_run: If True, logs actions without actually killing processes. Returns: A dictionary summarizing the examination and killing of processes. """ settings = Settings(idle_seconds=idle_seconds, process_names=process_names or DEFAULT_PROCESSES, dry_run=dry_run) examined_count = 0 killed_count = 0 killed_processes = [] for proc in psutil.process_iter(['pid', 'name', 'create_time']): if proc.info['name'] in settings.process_names: examined_count += 1 if is_process_idle(proc, settings.idle_seconds): if settings.dry_run: print(f"Dry run: Would kill process {proc.info['name']} (PID: {proc.info['pid']}) - idle for > {settings.idle_seconds}s", file=sys.stderr) else: try: print(f"Killing process {proc.info['name']} (PID: {proc.info['pid']}) - idle for > {settings.idle_seconds}s", file=sys.stderr) proc.kill() killed_count += 1 killed_processes.append({"name": proc.info['name'], "pid": proc.info['pid']}) except (psutil.NoSuchProcess, psutil.AccessDenied): print(f"Failed to kill process {proc.info['name']} (PID: {proc.info['pid']})", file=sys.stderr) return { "examined": examined_count, "killed": killed_count, "killed_processes": killed_processes, "timestamp": datetime.utcnow().isoformat() + "Z", "dry_run": settings.dry_run, "idle_seconds_threshold": settings.idle_seconds, "process_names_monitored": settings.process_names, } def main(): """Main entry point for the CLI.""" # FastMCP handles CLI parsing and tool execution mcp.run() if __name__ == "__main__": main()