dev-server-sandbox

name	dev-server-sandbox
description	Run multiple isolated xum dev-server instances (temp XUM_ROOT + free ports)

dev-server sandbox instances

make dev-server starts the xum backend server, which uses a lockfile at:

• <XUM_ROOT>/server.lock (defaults to ~/.xum-dev/server.lock in development)

This means you can only run one dev server per xum 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 XUM_ROOT.

Quick start

make dev-server-sandbox

What it does

• Creates a fresh temporary XUM_ROOT directory
• Copies these files into the sandbox if present (unless disabled by flags):
  • providers.jsonc (provider config)
  • config.json (project list)
  • Each file is seeded independently from the first root that has it ($XUM_ROOT, then leftover $MUX_ROOT, then ~/.xum[-dev], then leftover ~/.mux[-dev] / ~/.cmux), so a root with only config.json doesn't drop provider config
• Provider credential env vars are stripped from the server's env when they could silently override or mismatch the intended setup: all of them with --clean-providers (including Bedrock's AWS_REGION and AWS_BEARER_TOKEN_BEDROCK; shared AWS credentials like AWS_PROFILE are kept); otherwise only env vars that would shadow a seeded entry that has an but no explicit (API key env vars are always kept so env-key fallback still works)