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/arcjet/arcjet-pluginWrote 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/arcjet/arcjet-plugin/arcjet-express)<a href="https://agentmods.dev/rules/arcjet/arcjet-plugin/arcjet-express"><img src="https://agentmods.dev/badge/rules/arcjet/arcjet-plugin/arcjet-express/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/arcjet/arcjet-plugin/arcjet-express"><img src="https://agentmods.dev/badge/rules/arcjet/arcjet-plugin/arcjet-express.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 | $0.00000 | $0.00324 |
| Opus 5.5 | $0.00000 | $0.00130 |
| Sonnet 5.5 | $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 1mo 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
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.
- 1mo ago 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 24d 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.
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