nextjs-css-agent-components: Instructions file for Codex

AGENTS.md

Operating manual for AI agents working in nextjs-css-agent-components. Read this end-to-end before editing.

What this repo is

A Next.js 16 + React 19 + vanilla-CSS starter from Internet Development Studio. It powers wireframes.internet.dev and acts as the studio's design-system reference. Everything is intentionally vanilla — no Tailwind, no SASS, no PostCSS plugins, no CSS-in-JS, no UI library, no test runner, no state manager. Styles are CSS Modules using native CSS nesting (the & selector is plain CSS, compiled by Next.js's built-in Lightning CSS — no preprocessor required). The look is a precise, monospace-leaning, low-chrome wireframe aesthetic, and the precision is the product. Pixel values, type tokens, and theme variables are deliberate and should not be paraphrased away.

The package was previously named nextjs-sass-starter. SASS has never been a dependency in the current codebase — all styling is vanilla CSS. The package is now nextjs-css-agent-components.

Run / build

Requires Node.js >=22 (see engines in package.json).

• npm install — package-lock.json is gitignored, so npm ci does not work on a fresh clone
• npm run dev — Next dev server on port 10000
• npm run build — production build (TypeScript build errors are NOT ignored; see next.config.ts)
• npm run start — production server on port 10000
• npm run format — Prettier write across **/*.{tsx,ts,js,css,json,md}
• npm run format:check — Prettier check (reports unformatted files without writing)

There is no test runner and no linter configured. The only build-time gate is next build, which typechecks the whole tsconfig.json project with the local TypeScript 7 tsc CLI. TypeScript 7 has no JavaScript compiler API, so tools that need it (ts-node, language-service plugins such as the next entry in tsconfig.json) do not run against it. Don't add a test runner or ESLint config without being asked.

Version-matched Next.js docs ship in node_modules/next/dist/docs/; prefer them over remembered APIs. agentRules: false in next.config.ts keeps next dev from rewriting this file.