App Builder
Orchestrate specialist agents through mandatory planning, plan verification, and parallel database, backend, and frontend work when shipping a new app from scratch.
Overview
App Builder is an agent skill most often used in Build (also Validate scope) that orchestrates planner and specialist agents through a mandatory plan file and verification checkpoint before database, backend, and fronten
Install
npx skills add https://github.com/sickn33/antigravity-awesome-skills --skill app-builderWhat is this skill?
- Hard checkpoint: refuses to run specialists until {task-slug}.md exists in project root
- Project Planner agent for task breakdown, dependency graph, and file-structure planning
- Parallel specialist lanes for database, backend, and frontend after plan verification
- Orchestrator pattern designed for multi-agent app construction pipelines
- Mandatory checkpoint verifies {task-slug}.md in project root before specialists run
- Pipeline includes Project Planner plus database, backend, and frontend specialist lanes
Adoption & trust: 816 installs on skills.sh; 40.1k GitHub stars; 3/3 security scanners passed (skills.sh audits).
What problem does it solve?
You want a full app built with agents but keep starting implementation without an approved task plan or coordinated specialists.
Who is it for?
Solo builders greenfielding SaaS or API-backed apps who already use multi-agent workflows and can supply a clear product goal.
Skip if: Tiny one-file scripts, repos with an approved spec and plan already in place, or teams that forbid root-level plan artifacts.
When should I use this skill?
Starting a new full-stack app build or major greenfield feature that needs coordinated specialist agents and a root-level plan file.
What do I get? / Deliverables
You get a verified {task-slug}.md in the project root and coordinated database, backend, and frontend agent work aligned to that plan—then you invoke testing and ship skills separately.
- {task-slug}.md project plan with tasks and dependencies
- Coordinated implementation across database, backend, and frontend agents
Recommended Skills
Journey fit
Spans multiple journey phases - primary shelf plus alternate fits below.
Canonical shelf is build because the orchestrator’s job is to produce a full application stack; planning is a gated sub-step, not a separate journey stop. PM subphase fits task breakdown, dependency graphs, mandatory root-level plan files, and checkpoint gates before specialists run.
Where it fits
Break a product idea into tasks and a dependency graph before any implementation agents run.
Verify {task-slug}.md exists, then dispatch database, backend, and frontend specialists in parallel.
Continue the orchestrated lane after the plan checkpoint instead of improvising API structure.
How it compares
Use instead of asking one agent to “build the whole app” without a mandatory plan gate or specialist split.
Common Questions / FAQ
Who is app-builder for?
Indie and solo builders using Claude Code, Cursor, or similar agents who want a structured orchestrator for full-stack app generation with enforced planning first.
When should I use app-builder?
In Validate when you need a dependency-aware task plan before coding; in Build when you are ready to run database, backend, and frontend specialists in parallel after {task-slug}.md is verified; less often in Operate when rebuilding a major subsystem with the same pipeline.
Is app-builder safe to install?
Treat it like any orchestration skill that may drive filesystem and multi-step agent work—review the Security Audits panel on this Prism page and your marketplace source before enabling in production repos.
SKILL.md
READMESKILL.md - App Builder
# Agent Coordination > How App Builder orchestrates specialist agents. ## Agent Pipeline ``` ┌─────────────────────────────────────────────────────────────┐ │ APP BUILDER (Orchestrator) │ └─────────────────────────────────────────────────────────────┘ │ ▼ ┌─────────────────────────────────────────────────────────────┐ │ PROJECT PLANNER │ │ • Task breakdown │ │ • Dependency graph │ │ • File structure planning │ │ • Create {task-slug}.md in project root (MANDATORY) │ └─────────────────────────────────────────────────────────────┘ │ ▼ ┌─────────────────────────────────────────────────────────────┐ │ CHECKPOINT: PLAN VERIFICATION │ │ 🔴 VERIFY: Does {task-slug}.md exist in project root? │ │ 🔴 If NO → STOP → Create plan file first │ │ 🔴 If YES → Proceed to specialist agents │ └─────────────────────────────────────────────────────────────┘ │ ┌───────────────────┼───────────────────┐ ▼ ▼ ▼ ┌─────────────────┐ ┌─────────────────┐ ┌─────────────────┐ │ DATABASE │ │ BACKEND │ │ FRONTEND │ │ ARCHITECT │ │ SPECIALIST │ │ SPECIALIST │ │ │ │ │ │ │ │ • Schema design │ │ • API routes │ │ • Components │ │ • Migrations │ │ • Controllers │ │ • Pages │ │ • Seed data │ │ • Middleware │ │ • Styling │ └─────────────────┘ └─────────────────┘ └─────────────────┘ │ │ │ └───────────────────┼───────────────────┘ ▼ ┌─────────────────────────────────────────────────────────────┐ │ PARALLEL PHASE (Optional) │ │ • Security Auditor → Vulnerability check │ │ • Test Engineer → Unit tests │ │ • Performance Optimizer → Bundle analysis │ └─────────────────────────────────────────────────────────────┘ │ ▼ ┌─────────────────────────────────────────────────────────────┐ │ DEVOPS ENGINEER │ │ • Environment setup │ │ • Preview deployment │ │ • Health check │ └─────────────────────────────────────────────────────────────┘ ``` ## Execution Order | Phase | Agent(s) | Parallel? | Prerequisite | CHECKPOINT | |-------|----------|-----------|--------------|------------| | 0 | Socratic Gate | ❌ | - | ✅ Ask 3 questions | | 1 | Project Planner | ❌ | Questions answered | ✅ **PLAN.md created** | | 1.5 | **PLAN VERIFICATION** | ❌ | PLAN.md exists | ✅ **File exists in root** | | 2 | Database Architect | ❌ | Plan ready | Schema defined | | 3 | Backend Specialist | ❌ | Schema ready | API routes created | | 4 | Frontend Specialist | ✅ | API ready (partial) | UI components ready | | 5 | Security Auditor, Test Engineer | ✅ | Code ready | Tests & audit pass | | 6 | DevOps Engineer | ❌ | All code ready | Deployment ready | > 🔴 **CRITICAL:** Phase 1.5 is MANDATORY. No specialist agents proceed without PLAN.md verification. # Feature Building > How to analyze and implement new features. ## Feature Analysis ``` Request: "add payment system" Analysis: ├── Required Changes: │ ├── Database: orders, payments tables │ ├── Backend: /api/checkout, /api/webhooks/stripe │ ├── Frontend: CheckoutForm, PaymentSuccess │ └── Config: Stripe API keys │ ├── Dependencies: