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/arcjet/arcjet-plugin/arcjet-expressgit clone --depth 1 https://github.com/arcjet/arcjet-pluginWhat 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 | $0.00000 | $0.00324 |
| Opus 5 | $0.00000 | $0.00162 |
| Sonnet 5 | $0.00000 | $0.00065 |
| Haiku 4.5 | $0.00000 | $0.00032 |
Grade A, and why
arcjet-express 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.
What it actually says
Arcjet + Node.js Frameworks
- Use the correct adapter package:
- Express / Node.js / Hono:
@arcjet/node - Fastify:
@arcjet/fastify - NestJS:
@arcjet/nest - SvelteKit:
@arcjet/sveltekit - Remix:
@arcjet/remix - React Router:
@arcjet/react-router - Astro:
@arcjet/astro - Bun:
@arcjet/bun - Deno:
npm:@arcjet/deno
- Express / Node.js / Hono:
- Do NOT use as Express middleware (
app.use()). Callprotect()inside individual route handlers. - Pass the framework's request object directly:
aj.protect(req). - For apps behind proxies/load balancers: set
proxies: ["<lb-ip>"]on the Arcjet client options. - Ref: https://docs.arcjet.com/llms.txt
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 · 30 lines · 0 tokens per session scan A f3e544883cb1
arcjet-express is a cursor rule published in the GitHub repository arcjet/arcjet-plugin (1 stars, last pushed 7d ago), licensed Apache-2.0. It costs nothing until one of its globs matches a file; then it loads 324 tokens. 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.
Other cursor rules, from other repositories
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.
typescript
Changes to these high-fan-out internals can affect every message, delta, element, or rerun. Keep work in them minimal, and benchmark changes with representative stress-test apps.
coolify-ai-docs
Master reference to all Coolify AI documentation in .ai/ directory.
python_lib
Tips and guidelines specific to the development of the Streamlit Python library, not applicable to scripts and e2e tests.
specs
This directory contains product and tech specs for Streamlit features.