Agent skill

local-dev-server

Local dev server management — start, stop, clean restart, fix cache corruption, port conflicts. Use this skill whenever the dev server needs launching or is misbehaving.

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Forks 31

Install this agent skill to your Project

npx add-skill https://github.com/majiayu000/claude-skill-registry/tree/main/skills/other/local-dev-server-acurioustractor-empathy-ledger-v2-2

SKILL.md

Local Dev Server

When to Use

  • Starting/stopping dev server
  • "Address already in use" errors
  • Infinite loading spinner / broken pages after build
  • .next cache corruption (vendor-chunks ENOENT, 404 on static chunks)
  • Server crashes and needs restart
  • After major code changes or branch switches

Standard Start (Clean)

Always prefer a clean start to avoid stale cache issues:

bash
# 1. Kill any existing process on port 3030
lsof -ti:3030 | xargs kill -9 2>/dev/null

# 2. Clean .next cache (prevents stale vendor-chunk errors)
rm -rf .next

# 3. Start dev server in background
npx next dev -p 3030 &

# 4. Wait for ready, then verify
sleep 8 && curl -s -o /dev/null -w "%{http_code}" http://localhost:3030

First page load after clean start takes ~20-30s to compile. This is normal.

Quick Restart (No Cache Clean)

Only use when you know the cache is fine (small code edits):

bash
lsof -ti:3030 | xargs kill -9 2>/dev/null
npx next dev -p 3030 &

PM2 (Persistent Server)

For long sessions where server should auto-restart on crash:

bash
# Start
pm2 start npm --name "empathy-ledger" -- run dev

# Restart
pm2 restart empathy-ledger

# Clean restart (fixes cache issues)
pm2 stop empathy-ledger && rm -rf .next && pm2 start empathy-ledger

# Logs
pm2 logs empathy-ledger --lines 50

# Stop
pm2 stop empathy-ledger

Troubleshooting

Infinite spinner / blank page

bash
# Cache corruption — clean restart fixes it
lsof -ti:3030 | xargs kill -9 2>/dev/null
rm -rf .next
npx next dev -p 3030 &

Port already in use

bash
lsof -ti:3030 | xargs kill -9 2>/dev/null
npx next dev -p 3030 &

API returns 401 when it shouldn't

  • Check browser has valid session cookies
  • Try logging out and back in at /auth/signin
  • The API auth middleware reads cookies — curl without cookies will always 401

Vendor-chunks ENOENT / 404 on static chunks

bash
rm -rf .next
# Restart server

Verification Checklist

After starting the server, verify:

  1. curl -s -o /dev/null -w "%{http_code}" http://localhost:3030 returns 200 or 307
  2. Navigate to target page in browser
  3. Check server logs for compilation errors

Key URLs

Related Skills

  • deployment-workflow — Production deployment
  • supabase-connection — Database setup

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