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.
npx agentmods add rules/ofershap/tailwind-best-practices/best-practicesgit clone --depth 1 https://github.com/ofershap/tailwind-best-practicesWhat 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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.00272 | $0.00272 |
| Opus 5 | $0.00136 | $0.00136 |
| Sonnet 5 | $0.00054 | $0.00054 |
| Haiku 4.5 | $0.00027 | $0.00027 |
Grade A, and why
best-practices 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 3d 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.
What it actually says
Before generating Tailwind classes, verify they exist in v4 - do NOT use v3-only classes.
Use CSS-first @theme configuration, not tailwind.config.js. Define design tokens in a CSS file with @theme { --color-, --font-, --breakpoint-*, etc. }.
Use modern opacity syntax (bg-red-500/50) not bg-opacity-50 or text-opacity-25.
Use @import "tailwindcss" not @tailwind base/components/utilities directives.
For gradients, use bg-linear-to-r and bg-linear-45 (angle) - v4 prefers linear over gradient naming for directional gradients.
Use parentheses for CSS variables in arbitrary values: bg-(--brand-color) not bg-[--brand-color].
For grid-cols, grid-rows, object-position arbitrary values use underscores for spaces: grid-cols-[max-content_auto] not grid-cols-[max-content,auto].
Place the important modifier at the end of the class: flex! bg-red-500! not !flex !bg-red-500.
Use @container and @sm, @md, @max-md for container queries - style by parent size not viewport.
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.
- 3d ago First seen · 23 lines · 272 tokens per session scan A 1d9a9c270faf
best-practices is a cursor rule published in the GitHub repository ofershap/tailwind-best-practices (13 stars, last pushed 6mo ago), licensed MIT. It adds 272 tokens to every session, about $0.0014 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 2026-08-30.
Other cursor rules, from other repositories
tailwind-v4-anti-patterns
Tailwind CSS v4 anti-pattern detection. Prevents the most common AI-generated mistakes: version mixing, deprecated config patterns, and removed utilities.
tailwind-v4-config
Tailwind CSS v4 configuration rules for CSS and build tool files. Covers @theme, @source, @import, PostCSS, and Vite plugin setup.
tailwind-v4-core
Core Tailwind CSS v4 rules. Enforces correct v4 syntax and prevents common v3 fallbacks. Attach to all conversations involving Tailwind CSS.
tailwind-v4-migration
Tailwind CSS v3-to-v4 migration rules. Activated when the agent determines migration work is needed. Covers step-by-step upgrade process, common pitfalls, and automated migration tooling.
tailwind-v4-utilities
Tailwind CSS v4 utility class rules for template and markup files. Covers renamed classes, new utilities, container queries, gradients, and accessibility patterns.
best-practices
shadcn/ui Best Practices - enforces current best practices when working with shadcn/ui code.