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.
git clone --depth 1 https://github.com/BOXELS/cursor-rulesWrote 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.
[](https://agentmods.dev/rules/boxels/cursor-rules/security)<a href="https://agentmods.dev/rules/boxels/cursor-rules/security"><img src="https://agentmods.dev/badge/rules/boxels/cursor-rules/security/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.
<a href="https://agentmods.dev/rules/boxels/cursor-rules/security"><img src="https://agentmods.dev/badge/rules/boxels/cursor-rules/security.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.01437 | $0.01437 |
| Opus 5 | $0.00718 | $0.00718 |
| Sonnet 5 | $0.00287 | $0.00287 |
| Haiku 4.5 | $0.00144 | $0.00144 |
Grade A, and why
security 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 yesterday.
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.
How it starts
The opening of the file, as written. The whole thing — 66 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Security Rules
These rules are non-negotiable. Unlike other template sections, most items here are not placeholders — they apply to every project regardless of stack.
Output sanitization (XSS / HTML injection)
- Never render raw HTML from users, databases, or external APIs without sanitization. This includes rich text editors (TipTap, Quill, CKEditor), markdown renderers, and any content stored as HTML.
- If the framework provides a raw-HTML escape hatch (
dangerouslySetInnerHTML,innerHTML,v-html,{@html},| safe), treat every use as a security review point. The input must be sanitized before rendering. - Use [sanitization library, e.g. "DOMPurify", "sanitize-html", "bleach", "bluemonday"] for all HTML rendering from non-hardcoded sources.
- When interpolating variables into HTML strings, escape them. Never concatenate user-provided strings directly into HTML markup.
- Sanitize on output, not just on input. Data may be safe when stored but dangerous in a new rendering context.
- When writing a sanitization function, use an allowlist of tags and attributes — not a denylist. Denylists miss new attack vectors.
Secrets and API key management
- Public keys (safe for client): [list, e.g. "Supabase anon key, Stripe publishable key, analytics IDs"]. These can appear in client-side code.
- Secret keys (server-only): [list, e.g. "OpenAI API key, Stripe secret key, Supabase service role key, SMTP credentials"]. These must NEVER appear in client-side code, environment variables prefixed for client exposure, or client bundles.
- Third-party API calls requiring secret keys go through [server-side proxy, e.g. "Supabase Edge Functions", "Next.js Route Handlers", "Express API", "Django views"]. Never call OpenAI, Stripe (secret), or similar APIs directly from the browser.
- [Environment variable convention, e.g. "NEXT_PUBLIC_ prefix = client-visible. Everything else = server-only", "VITE_ prefix = client-visible". Audit your .env to verify no secret keys have the client prefix.]
- Never log secret keys, even in development. Never include them in error messages or API responses.
- [Secret rotation / vault, e.g. "Secrets managed in Vercel environment variables", "AWS Secrets Manager", "Doppler". Remove this line if not applicable yet.]
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.
- yesterday First seen · 66 lines · 1,437 tokens per session scan A be2c6103aa09
security is a cursor rule published in the GitHub repository BOXELS/cursor-rules (6 stars, last pushed yesterday), licensed MIT. It adds 1,437 tokens to every session, about $0.0072 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 2026-09-15.
Other cursor rules, from other repositories
ponytail
Ponytail, lazy senior dev mode. Always pick the simplest solution that works.
angular-20
This rule provides comprehensive best practices and coding standards for Angular development, focusing on modern TypeScript, standalone components, signals, and performance optimizations.
dev-standard
Apache Superset development standards and guidelines for Cursor IDE.
cli-error-handling
CLI command error handling patterns.
prefer-direct-imports-over-module-mocks
Prefer extracting a testable core over vi.mock / vi.resetModules when unit tests need to reach production logic entangled with config, env, or singletons.
control-plane-descriptors
Control plane descriptor and instance implementation patterns.