Ziv Daniel Nanoclaw Windows Dev Server Port Cleanup

Windows Dev Server Port Cleanup

Problem

Dev servers fail to start with "EADDRINUSE" or "port already in use" errors because previous processes didn't terminate cleanly, or background tasks are holding ports.

Context / Trigger Conditions

• NestJS error: Error: Failed to start server. Is port 3333 in use?
• Vite error: Port 3000 is already in use
• Error code: EADDRINUSE
• Previous dev session crashed or was force-closed
• Running bun run dev or npm run dev after switching branches
• Background shell tasks still running from previous commands

Solution

Step 1: Kill All Node/Bun Processes

In bash (Git Bash, WSL, or similar):

taskkill //F //IM node.exe 2>/dev/null || true
taskkill //F //IM bun.exe 2>/dev/null || true

Note: Use //F and //IM (double slashes) in bash environments on Windows.

Step 2: Verify Ports Are Free

netstat -an | grep -E "3000|3333"

Should return empty if ports are clear.

Step 3: Start Servers in Correct Order

For monorepos with API + Frontend:

# Terminal 1 - Start API first (it's the dependency)
cd apps/api && bun run src/main.ts

# Terminal 2 - Start Frontend (after API is ready)
cd apps/web && npx vite

Step 4: Verify Servers Are Running

# Check API
curl -s http://localhost:3333/api

# Check Frontend
curl -s http://localhost:3000 | head -5

Alternative: Using nohup for Background Processes

# Start API in background
cd apps/api && nohup bun run src/main.ts > /tmp/api.log 2>&1 &

# Wait for API to be ready
sleep 5

# Start web in background
cd apps/web && nohup npx vite > /tmp/web.log 2>&1 &

# Check logs if needed
tail -f /tmp/api.log
tail -f /tmp/web.log

Verification

1. netstat -an | grep 3333 shows LISTENING
2. curl http://localhost:3333/api returns a response (even 404 is OK)
3. curl http://localhost:3000 returns HTML

Common Pitfalls

Nx Plugin Errors

If you see Unable to resolve local plugin with import path @nx/nest/plugin:

• Don't use nx serve commands
• Run the server directly: bun run src/main.ts

Background Task Outputs

When using run_in_background in Claude Code:

• Output files may be empty initially
• Use sleep + cat to check logs
• Don't rely on immediate output

Windows Bash Syntax

• Use // for Windows flags in bash: taskkill //F //IM
• Use 2>/dev/null || true to suppress errors
• CMD syntax (for /f) doesn't work in bash

Example

Scenario: Starting a monorepo after previous session crashed

# 1. Clean up
taskkill //F //IM node.exe 2>/dev/null || true
taskkill //F //IM bun.exe 2>/dev/null || true

# 2. Wait a moment
sleep 2

# 3. Verify clean
netstat -an | grep -E "3000|3333"
# (should be empty)

# 4. Start API
cd /c/Repo/myproject/apps/api && bun run src/main.ts &

# 5. Wait for API
sleep 5

# 6. Start Web
cd /c/Repo/myproject/apps/web && npx vite &

# 7. Test
curl -s http://localhost:3333/api
curl -s http://localhost:3000 | head -3

Notes

• Always start API before frontend when frontend proxies to API
• Vite proxy config (in vite.config.ts) handles /api/* routing
• For production, use proper process managers (PM2, systemd)
• This skill is particularly relevant for Nx monorepos with Bun

References

• Vite Server Options
• NestJS Bootstrap

Source: ziv-daniel/nanoclaw — distributed by TomeVault.