app-builder

An application-building guide that turns a natural-language request into a planned full-stack application, choosing a project type, technology choices, structure, and supporting agents.

In plain words
What is it for?
Use it to start web applications, choose a technology stack, create project files, add features, and coordinate work across agents.
Why use it?
It provides a repeatable way to decide what to build and how to organize it, instead of making those choices ad hoc. It also includes starter structures for common application types.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/diillson/chatcli/app-builder
Any agent
npx skills add diillson/chatcli --skill app-builder
Clone the repo
git clone --depth 1 https://github.com/diillson/chatcli

Made for: Claude Code, Codex.

Per session 29 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 775 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 86% copy Near-identical to another mod in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00029 $0.00775
Opus 5 $0.00015 $0.00387
Sonnet 5 $0.00006 $0.00155
Haiku 4.5 $0.00003 $0.00077

Measured 2d ago against content hash 0169334a5ada, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

app-builder scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

This is a copy

86% identical to app-builder — 9 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

.agent/skills/app-builder/SKILL.md · 76 lines

How it starts

The opening of the file, as written. The whole thing — 76 lines — stays where its author put it; the contents beside it link to each section on GitHub.

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

Read the full file on GitHub · 76 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 76 lines · 29 tokens per session scan A 0169334a5ada

Subscribe to this mod's changes

app-builder is a skill published in the GitHub repository diillson/chatcli (89 stars, last pushed 3d ago), licensed Apache-2.0. It adds 29 tokens to every session and 775 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. It is 86% identical to app-builder, differing in 9 lines, and is treated as a copy.