smolcoder

smolcoder starts a persistent microsandbox microVM for a workspace, mounts the project at /workspace, and exposes it through SSH for shells and IDEs.

smolcoder ensure
smolcoder ssh
smolcoder open --ide code
smolcoder open --ide intellij

What it manages

• Stable per-workspace sandbox names
• Create/start/stop/delete through the Rust microsandbox crate
• A bind mount of the current workspace at /workspace
• A detached microVM that survives the wrapper process
• A per-workspace OpenSSH config snippet using ProxyCommand
• Generated per-workspace SSH keys under the user state directory
• Per-workspace state under the user state directory
• A JetBrains-ready base image with OpenSSH, curl, and mise

Usage

# Create or start the current workspace sandbox.
smolcoder ensure

# Interactive shell through OpenSSH + the generated ProxyCommand snippet.
smolcoder ssh

# Run a command through the same SSH path.
smolcoder ssh -- 'pwd'

# Print the generated ssh_config path.
smolcoder ssh config

# Use regular OpenSSH.
cfg="$(smolcoder ssh config)"; host="$(awk '/^Host /{print $2; exit}' "$cfg")"; ssh -F "$cfg" "$host"

# Serve an SSH listener in the foreground, matching msb's ssh serve shape.
smolcoder ssh serve

# Open IDEs over SSH.
smolcoder open --ide code
smolcoder open --ide intellij

# Stop or delete the sandbox.
smolcoder stop
smolcoder delete

Useful options:

smolcoder ensure --workspace /path/to/repo --name smolcoder-myrepo
smolcoder ensure --port 2223
smolcoder ensure --public-key ~/.ssh/id_ed25519.pub --identity-file ~/.ssh/id_ed25519
smolcoder ensure --cpus 2 --mem 1024
smolcoder open --ide intellij   # uses ghcr.io/manuschillerdev/smolcoder-base:latest and starts guest OpenSSH
smolcoder ensure --recreate

Requirements

• Linux with KVM enabled, or macOS with Apple Silicon
• ssh in PATH for OpenSSH, VS Code Remote-SSH, and JetBrains Gateway flows
• code in PATH for VS Code launches

The default guest image is debian:bookworm-slim. JetBrains mode defaults to ghcr.io/manuschillerdev/smolcoder-base:latest, which includes OpenSSH, curl, and mise. A small guest init script still injects per-workspace SSH keys and starts OpenSSH for Gateway's long-lived tunnels.