Most agent coding demos stop at a chat transcript. Witloop is an open plugin that runs a Spec-driven loop from idea to pull request on four hosts: Cursor, Claude Code, GitHub Copilot CLI, and Grok Build. One install, five entry points — setup, scan, Dev, RPA, add-issues — with you speaking at brainstorm and a design gate; research, plan, build, check, and ship run autonomously after that. I'll show how /wit:dev routes feature vs bug-fix vs investigation, how /wit:rpa turns a UiPath PDD into REFramework or Maestro work, what lands in .wit/ on a project, and lessons from shipping the same skills across four agent hosts. Repo: https://github.com/Wittenberger-Industries/witloop