Claude-skill-registry dev-server-sandbox

Run multiple isolated mux dev-server instances (temp MUX_ROOT + free ports)

install

source · Clone the upstream repo

git clone https://github.com/majiayu000/claude-skill-registry

Claude Code · Install into ~/.claude/skills/

T=$(mktemp -d) && git clone --depth=1 https://github.com/majiayu000/claude-skill-registry "$T" && mkdir -p ~/.claude/skills && cp -r "$T/skills/data/dev-server-sandbox" ~/.claude/skills/majiayu000-claude-skill-registry-dev-server-sandbox && rm -rf "$T"

manifest: skills/data/dev-server-sandbox/SKILL.md

tags

#dev-server #sandbox #multiplex #temp-root #port-alloc

source content

dev-server

sandbox instances

make dev-server

starts the mux backend server, which uses a lockfile at:

<MUX_ROOT>/server.lock

(defaults to

~/.mux-dev/server.lock

in development)

This means you can only run one dev server per mux root directory.

This skill documents the repo workflow for starting multiple dev-server instances in parallel (including from different git worktrees) by giving each instance its own temporary

MUX_ROOT

Quick start

make dev-server-sandbox

What it does

Creates a fresh temporary
```
MUX_ROOT
```
directory
Copies these files into the sandbox if present:
- ```
providers.jsonc
```
  (provider config)
- ```
config.json
```
  (project list)
Picks free ports (
```
BACKEND_PORT
```
,
```
VITE_PORT
```
)
Allows all hosts (
```
VITE_ALLOWED_HOSTS=all
```
) so it works behind port-forwarding domains
Runs
```
make dev-server
```
with those env overrides

Options

# Use a specific root to seed from (defaults to ~/.mux-dev then ~/.mux)
SEED_MUX_ROOT=~/.mux-dev make dev-server-sandbox

# Keep the sandbox root directory after exit (useful for debugging)
KEEP_SANDBOX=1 make dev-server-sandbox

# Pin ports (must be different)
BACKEND_PORT=3001 VITE_PORT=5174 make dev-server-sandbox

# Override which make binary to use
MAKE=gmake make dev-server-sandbox

Security notes

```
providers.jsonc
```
may contain API keys.
The sandbox root directory is created on disk (usually under your system temp dir).
This flow intentionally does not copy
```
secrets.json
```
.