I don't understand why I keep seeing posts like this, but nobody appears to know that DevContainers exist.

In a Jetbrains IDE, for example, you check a devcontainer.json file into your repository. This file describes how to build a Docker image (or points to a Dockerfile you already have). When you open up a project, the IDE builds the Docker image, automatically installs a language-server backend into it, and launches a remote frontend connected to that container (which may run on the same or a different machine from where the frontend runs).

If you do anything with an AI agent, that thing happens inside the remote container where the project code files are. If you compile anything, or run anything, that happens in the container too. The project directory itself is synced back to your local system but your home directory (and all its credentials) are off-limits to things inside the container.

It's actually easier to do this than to not, since it provides reusable developer tooling that can be shared among all team members, and gives you consistent dependency versions used for local compilation/profiling/debugging/whatever.

DevContainers are supported by a number of IDEs including VSCode.

You should be using them for non-vibe projects. You should DEFINITELY be using them for vibe projects.

The main Claude Code GitHub repo even has a Devcontainer config:

https://github.com/anthropics/claude-code

It's a great starting point, and can be customized as needed. With the devcontainer CLI, you can even use it from a terminal, no GUI/IDE required.

Yeah, it's easy to vibecode and review a docker sandbox, too. If you run containers with

   --runtime=runsc
   --cap-drop=ALL
   --security-opt no-new-privileges:true

Has anyone figured out a good way to use (neo)vim with devcontainers?