Reverse-engineered Codex background computer-use API released

A developer going by anupamb has published `background-computer-use`, an open-source Swift project that reverse-engineers OpenAI Codex's background computer-use plugin for macOS. The runtime exposes a loopback HTTP API and uses macOS Accessibility, Screen Recording, and native window-event APIs to dispatch clicks, scrolling, text input, key presses, and window motion against target windows — all without hijacking the user's pointer. A startup script builds the Swift package, self-signs an `.app` bundle, installs it to `~/Applications/BackgroundComputerUse.app`, and writes a runtime manifest to `$TMPDIR/background-computer-use/runtime-manifest.json` for agents to discover the active local URL.