prototype-first

prototype-first is a skill for Claude Code from parisgroup-ai/imersao-ia-setup. It costs 97 tokens per session (598 once invoked), scanned A, original, MIT.

A workflow for designing web interfaces in a prototype before building the production version. It routes full web-app work to Design OS and smaller interface work to a frontend design process, while skipping backend, command-line, and library tasks.

In plain words
What is it for?
Use it before creating or redesigning web screens, pages, or flows to define the visual system, prototype screens, preview them locally, and prepare a development handoff.
Why use it?
It lets you change the layout and visual direction before those decisions are built into production code.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin. Also seen: mentions Claude Code.

Part of the imersao plugin — 51 skills, 7 commands shipped together

Good fit Use it before creating or redesigning web screens, pages, or flows to define the visual system, prototype screens, preview them locally, and prepare a development handoff.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/parisgroup-ai/imersao-ia-setup/prototype-first
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.

Any agent
npx skills add parisgroup-ai/imersao-ia-setup --skill prototype-first
Clone the repo
git clone --depth 1 https://github.com/parisgroup-ai/imersao-ia-setup

Made for: Claude Code.

Or install imersao, the plugin that ships this one along with the rest of its 51 skills, 7 commands.

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 prototype-first

README.md
[![agentmods](https://agentmods.dev/badge/skills/parisgroup-ai/imersao-ia-setup/prototype-first/github.svg)](https://agentmods.dev/skills/parisgroup-ai/imersao-ia-setup/prototype-first)
Your own site
<a href="https://agentmods.dev/skills/parisgroup-ai/imersao-ia-setup/prototype-first"><img src="https://agentmods.dev/badge/skills/parisgroup-ai/imersao-ia-setup/prototype-first/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for prototype-first

Your own site · 80×15
<a href="https://agentmods.dev/skills/parisgroup-ai/imersao-ia-setup/prototype-first"><img src="https://agentmods.dev/badge/skills/parisgroup-ai/imersao-ia-setup/prototype-first.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 97 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 598 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 $0.00097 $0.00598
Opus 5 $0.00048 $0.00299
Sonnet 5 $0.00019 $0.00120
Haiku 4.5 $0.00010 $0.00060

Measured 9d ago against content hash 2109e2cf992b, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

prototype-first 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 9d 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.

plugins/imersao/skills/prototype-first/SKILL.md · 55 lines

What it actually says

Prototype First

Princípio: nunca construa código de UI de produção duas vezes. Antes de escrever a tela "pra valer", prototipe e valide o design — é mais barato mudar um protótipo do que refatorar código já integrado.

Quando esta skill se aplica

  • ✅ Vai criar/redesenhar tela, página ou fluxo de uma aplicação web.
  • Auto-pule (não use) quando o trabalho for backend, CLI, script ou biblioteca sem interface — vá direto implementar.

Roteamento

Frontend web completo → Design OS (público)

Para um app ou conjunto de telas, prototipe no Design OS da Builder Methods. Ele roda localmente e é open-source — sem dependências privadas:

git clone https://github.com/buildermethods/design-os.git ../<projeto>-design
cd ../<projeto>-design
git remote remove origin
npm install
npm run dev          # http://localhost:3000

Depois, dentro dessa pasta com o Claude Code aberto, conduza o fluxo de design:

  1. /product-vision — define visão, roadmap e formato dos dados
  2. /design-tokens e /design-shell — sistema visual e casco do app
  3. /design-screen — uma tela por seção (preview vivo em localhost:3000)
  4. /export — gera o handoff (componentes React + Tailwind + specs)

Revise o protótipo vivo e ajuste em linguagem natural antes de exportar. Só então parta para a implementação.

Na imersão: prototipo marca cada tela onda 1 ou depois; implementar constrói só a onda 1 com writing-plans + executing-plans. Caderno: caderno/Comece aqui.md.

UI pequena / um componente isolado → frontend-design

Para um único componente ou uma tela simples que não justifica subir o Design OS, use a skill frontend-design para gerar a UI direto, com qualidade visual.

Regra de ouro

Saiu do protótipo aprovado? Só aí escreva o código de produção — portando o que foi validado, não inventando de novo.

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. 9d ago First seen · 55 lines · 97 tokens per session scan A 2109e2cf992b

Subscribe to this mod's changes

prototype-first is a skill published in the GitHub repository parisgroup-ai/imersao-ia-setup (1 stars, last pushed 27d ago), licensed MIT. It adds 97 tokens to every session and 598 once invoked, about $0.0005 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.

Related

Other skills, from other repositories

top-design

Create award-winning, immersive web experiences at the level of Awwwards-featured agencies. Use when the user mentions "Awwwards quality", "make my site stunning", "scroll animations", "parallax storytelling", "cinematic web design", "portfolio site", or "brand experience". Also trigger when elevating a standard…

wondelai/skills · 113 tokens

web-typography

Select, pair, and implement typefaces for web projects. Use when the user mentions "font pairing", "which typeface", "line height", "responsive typography", "web font loading", "type hierarchy", "variable fonts", "FOUT/FOIT", "typographic scale", or "the text is hard to read". Also trigger when choosing between system…

wondelai/skills · 128 tokens

refactoring-ui

Audit and fix visual hierarchy, spacing, color, and depth in web UIs. Use when the user mentions "my UI looks off" (or amateur/unprofessional), "fix the design", "Tailwind styling", "color palette", "visual hierarchy", "design system", "spacing scale", or "component styling". Also trigger when building consistent…

wondelai/skills · 132 tokens

design-to-drupal-paragraph

Create Drupal paragraph types from Figma designs or screenshots using the design-specialist agent. Auto-activates when user provides a design reference and asks to create a Drupal paragraph type, content component, or layout section. Invoke when user says "create a Drupal paragraph from this design", "convert this…

kanopi/cms-cultivator · 81 tokens

design-to-wp-block

Create WordPress block patterns from Figma designs or screenshots using the design-specialist agent. Auto-activates when user provides a Figma URL or design mockup and asks to create a WordPress block pattern, component, or section. Invoke when user says "create a WordPress block from this design", "convert this Figma…

kanopi/cms-cultivator · 88 tokens

html-prototype

A method for creating single-file HTML mockups that open in a browser and follow a project's design tokens, such as its fonts, colours, spacing, corners, and shadows.

mayuemarsha-del/pm-skills · 97 tokens