Thomas Ptacek discusses VSCode's SSH remote editing agent, contrasting it with Emacs' Tramp. Tramp lives off the land on a remote connection, running Bourne shell commands. VSCode mounts a full-scale invasion: it runs a Bash snippet stager that downloads an agent, including a binary installation of Node.

The agent establishes a WebSockets connection back to the running VSCode front-end. The underlying protocol can wander the filesystem, edit arbitrary files, launch its own shell PTY processes, and persist itself. In security-world, there's a name for tools that work this way—murid in nature.

Ptacek says he would be nervous about letting people VSCode-remote-edit on dev servers and apoplectic if that happened during an incident on something in production. However, it turns out this doesn't matter for getting a custom connection to a Fly Machine working in VSCode.