> ## Documentation Index > Fetch the complete documentation index at: https://mux.coder.com/llms.txt > Use this file to discover all available pages before exploring further. # Docker Runtime > Run agents in isolated Docker containers Docker runtime runs each workspace in a separate Docker container, providing full isolation. ## Why use Docker runtime * **Full isolation**: Each workspace runs in its own container with no shared state * **Reproducible environments**: Pin exact images for consistent tooling * **Security**: Container sandboxing limits agent access to host system ## How it works 1. When you create a Docker workspace, Mux starts a container from your chosen image 2. Your project code is synced to `/src` inside the container via git bundle 3. Commands run inside the container with `docker exec` 4. Deleting the workspace removes the container ## Configuration Select Docker in the workspace creation UI and specify an image: * `node:20` - Node.js with git pre-installed * `python:3.12` - Python with git pre-installed * Custom images with your toolchain ## Credential sharing Check "Share credentials" when creating a Docker workspace to enable git authentication: * **SSH agent forwarding** — Your SSH keys work inside the container without copying private keys * **Git config** — Host `~/.gitconfig` is copied into the container so git has your identity and settings * **GitHub CLI** — If `GH_TOKEN` is set in [project secrets](/config/project-secrets), Mux runs `gh auth setup-git` to configure HTTPS authentication (requires `gh` CLI in the container image)