How do I install the App Builder skill?

Run npx skillmds@latest add rootcastleco/app-builder in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

Is App Builder safe to use?

SkillMD's automated safety review verdict for this skill is PASS. Independent scanners report: SkillSpector: PASS, Skill Scanner: PASS. Capability flags: makes network calls. SkillMD never runs a skill's scripts for you; review the SKILL.md before installing.

Which AI agents work with App Builder?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is App Builder free to use?

Yes. Installing skills from SkillMD is free, and the skill stays under its author's original license.

Who published App Builder?

rootcastleco (@rootcastleco) published this skill. Their other Agent Skills are listed on their SkillMD profile.

App Builder by rootcastleco — Agent Skill

Name: App Builder
Rating: 4.2 (5 reviews)
Author: rootcastleco

File contents

App Builder - Application Building Orchestrator

Analyzes user's requests, determines tech stack, plans structure, and coordinates agents.

🎯 Selective Reading Rule

Read ONLY files relevant to the request! Check the content map, find what you need.

File	Description	When to Read
`project-detection.md`	Keyword matrix, project type detection	Starting new project
`tech-stack.md`	2025 default stack, alternatives	Choosing technologies
`agent-coordination.md`	Agent pipeline, execution order	Coordinating multi-agent work
`scaffolding.md`	Directory structure, core files	Creating project structure
`feature-building.md`	Feature analysis, error handling	Adding features to existing project
`templates/SKILL.md`	Project templates	Scaffolding new project

📦 Templates (13)

Quick-start scaffolding for new projects. Read the matching template only!

Template	Tech Stack	When to Use
nextjs-fullstack	Next.js + Prisma	Full-stack web app
nextjs-saas	Next.js + Stripe	SaaS product
nextjs-static	Next.js + Framer	Landing page
nuxt-app	Nuxt 3 + Pinia	Vue full-stack app
express-api	Express + JWT	REST API
python-fastapi	FastAPI	Python API
react-native-app	Expo + Zustand	Mobile app
flutter-app	Flutter + Riverpod	Cross-platform mobile
electron-desktop	Electron + React	Desktop app
chrome-extension	Chrome MV3	Browser extension
cli-tool	Node.js + Commander	CLI app
monorepo-turborepo	Turborepo + pnpm	Monorepo

🔗 Related Agents

Agent	Role
`project-planner`	Task breakdown, dependency graph
`frontend-specialist`	UI components, pages
`backend-specialist`	API, business logic
`database-architect`	Schema, migrations
`devops-engineer`	Deployment, preview

Usage Example

User: "Make an Instagram clone with photo sharing and likes"

App Builder Process:
1. Project type: Social Media App
2. Tech stack: Next.js + Prisma + Cloudinary + Clerk
3. Create plan:
   ├─ Database schema (users, posts, likes, follows)
   ├─ API routes (12 endpoints)
   ├─ Pages (feed, profile, upload)
   └─ Components (PostCard, Feed, LikeButton)
4. Coordinate agents
5. Report progress
6. Start preview

When to Use

This skill is applicable to execute the workflow or actions described in the overview.

🏰 Rei Skills — Curated by Rootcastle Engineering & Innovation | Batuhan Ayrıbaş
Engineering Beyond Boundaries | admin@rootcastle.com

---name: app-builderdescription: Main application building orchestrator. Creates full-stack applications from natural language requests. Determines project type, selects tech stack, coordinates agents.---# App Builder - Application Building Orchestrator> Analyzes user's requests, determines tech stack, plans structure, and coordinates agents.## 🎯 Selective Reading Rule**Read ONLY files relevant to the request!** Check the content map, find what you need.| File | Description | When to Read ||------|-------------|--------------|| `project-detection.md` | Keyword matrix, project type detection | Starting new project || `tech-stack.md` | 2025 default stack, alternatives | Choosing technologies || `agent-coordination.md` | Agent pipeline, execution order | Coordinating multi-agent work || `scaffolding.md` | Directory structure, core files | Creating project structure || `feature-building.md` | Feature analysis, error handling | Adding features to existing project || `templates/SKILL.md` | **Project templates** | Scaffolding new project |---## 📦 Templates (13)Quick-start scaffolding for new projects. **Read the matching template only!**| Template | Tech Stack | When to Use ||----------|------------|-------------|| [nextjs-fullstack](templates/nextjs-fullstack/TEMPLATE.md) | Next.js + Prisma | Full-stack web app || [nextjs-saas](templates/nextjs-saas/TEMPLATE.md) | Next.js + Stripe | SaaS product || [nextjs-static](templates/nextjs-static/TEMPLATE.md) | Next.js + Framer | Landing page || [nuxt-app](templates/nuxt-app/TEMPLATE.md) | Nuxt 3 + Pinia | Vue full-stack app || [express-api](templates/express-api/TEMPLATE.md) | Express + JWT | REST API || [python-fastapi](templates/python-fastapi/TEMPLATE.md) | FastAPI | Python API || [react-native-app](templates/react-native-app/TEMPLATE.md) | Expo + Zustand | Mobile app || [flutter-app](templates/flutter-app/TEMPLATE.md) | Flutter + Riverpod | Cross-platform mobile || [electron-desktop](templates/electron-desktop/TEMPLATE.md) | Electron + React | Desktop app || [chrome-extension](templates/chrome-extension/TEMPLATE.md) | Chrome MV3 | Browser extension || [cli-tool](templates/cli-tool/TEMPLATE.md) | Node.js + Commander | CLI app || [monorepo-turborepo](templates/monorepo-turborepo/TEMPLATE.md) | Turborepo + pnpm | Monorepo |---## 🔗 Related Agents| Agent | Role ||-------|------|| `project-planner` | Task breakdown, dependency graph || `frontend-specialist` | UI components, pages || `backend-specialist` | API, business logic || `database-architect` | Schema, migrations || `devops-engineer` | Deployment, preview |---## Usage Example```User: "Make an Instagram clone with photo sharing and likes"App Builder Process:1. Project type: Social Media App2. Tech stack: Next.js + Prisma + Cloudinary + Clerk3. Create plan: ├─ Database schema (users, posts, likes, follows) ├─ API routes (12 endpoints) ├─ Pages (feed, profile, upload) └─ Components (PostCard, Feed, LikeButton)4. Coordinate agents5. Report progress6. Start preview```## When to UseThis skill is applicable to execute the workflow or actions described in the overview.---> 🏰 **Rei Skills** — Curated by [Rootcastle Engineering & Innovation](https://www.rootcastle.com) | Batuhan Ayrıbaş > Engineering Beyond Boundaries | admin@rootcastle.com

Frequently asked questions

App Builder