Phase Checkpoint

Purpose: Pause for human verification before proceeding to next phase. Quality gate.

When to Use

Call this skill at the end of each major phase:

• After Foundation setup
• After Auth implementation
• After Core features
• After Payments integration
• Before deployment

Checkpoint Process

1. Summary of Completed Work

List what was built this phase:

• Features implemented
• Files created/modified
• Commits made
• Tests passing

2. Verification Steps

Guide human through testing on Vercel preview:

# Push to trigger Vercel preview deployment
git push

# Check the Vercel preview URL (from deployment):
# - https://project-abc123.vercel.app
# - https://project-abc123.vercel.app/auth/login
# - https://project-abc123.vercel.app/dashboard

# ⚠️ NEVER use localhost - always test on real Vercel URLs

3. Checklist

Present verification checklist:

• UI renders correctly
• No console errors
• Core functionality works
• Auth flow complete (if applicable)
• Data persists to database (if applicable)
• Responsive on mobile

4. Decision Point

Ask human:

Phase [X] Complete. Ready to proceed to Phase [X+1]?

Options:

1. ✅ Approved - Continue to next phase
2. 🔧 Fix issues - [describe what's wrong]
3. ⏸️ Pause - Save state, continue later

5. State Update

Based on response:

• Approved: Update TodoWrite, proceed
• Fix issues: Address problems, re-verify
• Pause: Update STATE.md with current position

Example Checkpoint Output

━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
📋 PHASE 2 CHECKPOINT: Database & Auth
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

✅ Completed:
   • Supabase project connected
   • User profiles table created
   • RLS policies applied
   • Sign up / Sign in / Sign out working
   • Protected dashboard route

🧪 Verify (on Vercel preview URL):
   1. Go to https://[project].vercel.app
   2. Click "Sign Up" - create test account
   3. Check email for confirmation
   4. Confirm and verify redirect to dashboard
   5. Check Supabase → Auth → Users (should see new user)
   6. Click "Sign Out" - verify redirect to home

   ⚠️ Ensure Supabase auth redirects include your preview URL!

📝 Commits:
   • feat: Add Supabase auth configuration
   • feat: Create user profiles schema
   • feat: Implement auth UI components

━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Ready to proceed to Phase 3: Core Features?
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

Why Checkpoints Matter

From GSD methodology:

"You can't screw this part up. We have to make sure payments work properly. That's why we're taking so much time here."

Verification prevents:

• Building on broken foundations
• Deploying broken functionality
• Wasting time on features that don't work
• Context rot from debugging old issues

🔗 Workflow Integration

Part of ultraplan workflow: ultraplan creates phases → phase-checkpoint verifies each → repeat until complete.

Related: ultraplan skill (creates the phases), qa agent (testing), design-reviewer agent (visual verification).