App Builder — Application Building Orchestrator
Analyzes requirements, determines tech stack, plans structure, and coordinates agents.
🎯 Process Overview
User Request → Analyze → Select Stack → Plan → Scaffold → Coordinate → Verify
📦 Recommended Default Stack
| Layer |
Technology |
Alternative |
| Web Frontend |
Next.js 14+ |
Nuxt 3 |
| Mobile |
Expo (React Native) |
Flutter |
| Backend |
NestJS |
FastAPI |
| Database |
PostgreSQL + Prisma |
Supabase |
| Auth |
NextAuth / Firebase Auth |
Clerk |
| Hosting |
Vercel |
Firebase |
| Storage |
Cloudinary / Firebase Storage |
S3 |
🔗 Agent Coordination
| Agent |
Role |
When to Invoke |
planner |
Task breakdown, dependencies |
Starting any project |
architect |
System design, patterns |
Architecture decisions |
code-reviewer |
Quality, patterns |
After implementation |
security-reviewer |
Security posture |
Auth, payment features |
tdd-guide |
Test specifications |
Before/during implementation |
📋 Project Type Detection
| Keywords |
Project Type |
Default Stack |
| "web app", "website", "dashboard" |
Web Application |
Next.js + Prisma |
| "mobile app", "iOS", "Android" |
Mobile App |
Expo + NestJS API |
| "API", "backend", "server" |
API Service |
NestJS + Prisma |
| "landing page", "marketing" |
Static Site |
Next.js (static export) |
| "CLI", "command line" |
CLI Tool |
Node.js + Commander |
| "extension", "plugin" |
Browser Extension |
Chrome MV3 |
🏗️ Scaffolding Process
Step 1: Clarify Requirements
Before scaffolding, confirm:
1. Project type (web/mobile/API/etc.)
2. Core features (3-5 max for MVP)
3. Auth requirements (none/social/email)
4. Database needs (none/simple/complex)
Step 2: Create Plan
## Project Plan: [Name]
### Core Features
1. [Feature 1]
2. [Feature 2]
3. [Feature 3]
### Tech Stack
- Frontend: [choice]
- Backend: [choice]
- Database: [choice]
### File Structure
[directory tree]
### Implementation Order
1. Setup & configuration
2. Database schema
3. API endpoints
4. Frontend pages
5. Authentication
6. Testing
Step 3: Scaffold
# Example: Next.js project
npx create-next-app@latest ./project-name \
--typescript \
--eslint \
--tailwind \
--app \
--src-dir
Step 4: Coordinate Agents
1. Invoke planner → Task breakdown
2. Invoke architect → Design decisions
3. Execute tasks sequentially
4. Invoke tdd-guide → Add tests
5. Invoke code-reviewer → Final review
📁 Standard Directory Structures
Next.js Full-Stack
src/
├── app/ # Pages & routes
│ ├── api/ # API routes
│ └── (auth)/ # Auth pages
├── components/ # React components
├── lib/ # Utilities
├── server/ # Server-side logic
│ ├── db/ # Prisma client
│ └── services/ # Business logic
└── types/ # TypeScript types
NestJS API
src/
├── modules/ # Feature modules
│ ├── auth/
│ ├── users/
│ └── [feature]/
├── common/ # Shared utilities
│ ├── decorators/
│ ├── guards/
│ └── interceptors/
└── config/ # Configuration
Expo Mobile
src/
├── app/ # Expo Router screens
├── components/ # UI components
├── hooks/ # Custom hooks
├── services/ # API clients
├── stores/ # Zustand stores
└── utils/ # Helpers
✅ Post-Scaffold Checklist
Usage Example
User: "Create a task management app with user auth"
App Builder Process:
1. Project type: Web Application
2. Tech stack: Next.js + Prisma + NextAuth
3. Create plan:
├─ Database schema (users, tasks, lists)
├─ API routes (CRUD for tasks)
├─ Pages (dashboard, tasks, settings)
└─ Components (TaskCard, TaskList, etc.)
4. Scaffold project
5. Coordinate agents for implementation
6. Run verification loop