web-development-setup

web-development-setup is a skill for Claude Code, Codex from a2ngerer/claude_onboarding_agent. It costs 51 tokens per session (6,252 once invoked), scanned A, original, MIT.

A setup guide for Claude projects that build websites or web services, such as React, Next.js, Vue, or backend applications.

In plain words
What is it for?
Use it when onboarding a frontend, backend, full-stack, or static web project and updating its Claude instructions without replacing an existing file.
Why use it?
It helps establish project-specific coding rules, tool permissions, styling and linting conventions, and deployment references before development starts.

Skill for Claude CodeCodex

Part of the claude-onboarding-agent plugin — 16 skills, 4 agents, 1 hook shipped together

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/a2ngerer/claude_onboarding_agent/web-development-setup
Any agent
npx skills add a2ngerer/claude_onboarding_agent --skill web-development-setup
Clone the repo
git clone --depth 1 https://github.com/a2ngerer/claude_onboarding_agent

Made for: Claude Code, Codex.

Or install claude-onboarding-agent, the plugin that ships this one along with the rest of its 16 skills, 4 agents, 1 hook.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for web-development-setup

README.md
[![agentmods](https://agentmods.dev/badge/skills/a2ngerer/claude_onboarding_agent/web-development-setup.svg)](https://agentmods.dev/skills/a2ngerer/claude_onboarding_agent/web-development-setup)
Your own site
<a href="https://agentmods.dev/skills/a2ngerer/claude_onboarding_agent/web-development-setup"><img src="https://agentmods.dev/badge/skills/a2ngerer/claude_onboarding_agent/web-development-setup.svg" alt="Measured on agentmods" height="20"></a>
Per session 51 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 6,252 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found 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 5.1 $0.00051 $0.06252
Opus 5 $0.00026 $0.03126
Sonnet 5 $0.00010 $0.01250
Haiku 4.5 $0.00005 $0.00625

Measured 5d ago against content hash 2c2a8563949a, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-05, from the pricing page.

Security

Grade A, and why

web-development-setup 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 5d ago.

The scan reads SKILL.md. This mod also ships 1 executable file (type-check-hook.template.sh), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

skills/web-development-setup/SKILL.md · 403 lines

How it starts

The opening of the file, as written. The whole thing — 403 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Web Development Setup

This skill configures Claude for web application development — frontend SPAs, backend APIs, full-stack apps, and static sites. It is the right choice when the project centers on a JS/TS framework (Next.js, React, Vue, Svelte, SolidJS, Astro, Remix) or a web-backend stack (Node, Bun, Python FastAPI/Django, Go) serving HTTP traffic.

Use coding-setup for language-agnostic software projects (libraries, CLIs, generic services). Use design-setup for UI/UX design tooling (Figma, design systems) rather than application code.

Handoff context: Read skills/_shared/consume-handoff.md and run it with the handoff block (if any). The helper guarantees the following locals: detected_language, existing_claude_md, inferred_use_case, repo_signals, graphify_candidate. Use detected_language for all user-facing prose; generated file content stays in English.

Existing CLAUDE.md: If existing_claude_md: true, DO NOT overwrite it. Append a new delimited section at the end of the file:

<!-- onboarding-agent:start setup=web-development skill=web-development-setup section=claude-md -->
## Claude Onboarding Agent — Web Development Setup
...generated content...
<!-- onboarding-agent:end -->

If the delimited block already exists from a previous run (either the attributed form above or the legacy unattributed <!-- onboarding-agent:start --> form), replace only the content between the markers; leave the rest of the file untouched. Upgrade the opening marker to the attributed form while you are there — /upgrade-setup depends on it for detection.

Supporting Files

Read these on-demand at the step that invokes them. Do not read eagerly.

  • rule-file-templates.md — bodies of the .claude/rules/*.md files (Step 8)
  • framework-defaults.md — Q1/Q2-conditional styling and deploy-target matrix (Step 4), plus public env-var prefix table
  • gitignore-block.md — the .gitignore block and .env.example scaffold (Step 8)
  • document-skeletons.mdpackage.json, pyproject.toml, and per-stack install commands (Step 8)
  • type-check-hook.template.sh — bash source for the optional type-check PostToolUse hook, with <PM_EXEC> placeholder (Step 8)
  • skills/_shared/consume-handoff.md — orchestrator handoff parse + inline fallback (preamble, before Step 1)
  • skills/_shared/offer-superpowers.md — canonical Superpowers opt-in (Step 1)
  • skills/_shared/offer-github-mcp.md — canonical GitHub MCP offer (Step 7)
  • skills/_shared/offer-graphify.md — canonical Graphify opt-in (Step 9)

Read the full file on GitHub · 403 lines

Files

What ships with it

5 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 5d ago First seen · 403 lines · 51 tokens per session scan A 2c2a8563949a

Subscribe to this mod's changes

web-development-setup is a skill published in the GitHub repository a2ngerer/claude_onboarding_agent (5 stars, last pushed yesterday), licensed MIT. It adds 51 tokens to every session and 6,252 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

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