Freeze a running server and free its TCP port — without killing it. Resume later with the same PID, memory, and state. park reaches inside the target process and injects close(fd) via ptrace (Linux) or Mach thread injection (macOS) to release the listening socket. Resume recreates the listener at the same fd number. Works with uvicorn, FastAPI, Flask, python http.server, and more. Single binary, no deps. Install: curl -fsSL https://raw.githubusercontent.co... | sh