with-deno

Project guidance for using Deno 2, a runtime and toolkit for JavaScript and TypeScript. It lists supported Deno APIs and project practices for areas such as files, networking, processes, logging, and scheduled tasks.

In plain words
What is it for?
Building or reviewing Deno 2 applications, using Deno's file and network APIs, handling environment variables and processes, and following the project's runtime conventions.
Why use it?
It keeps generated or reviewed code aligned with the project's Deno 2 version and preferred built-in tools instead of relying on incompatible approaches.

Cursor rule for Cursor

Install

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.

agentmods
npx agentmods add rules/zackiles/deno-kit/with-deno
Clone the repo
git clone --depth 1 https://github.com/zackiles/deno-kit

Made for: Cursor.

Per session 0 Nothing until a file matches its globs; then the whole rule loads.
When invoked 10,350 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5 $0.00000 $0.10350
Opus 5 $0.00000 $0.05175
Sonnet 5 $0.00000 $0.02070
Haiku 4.5 $0.00000 $0.01035

Measured 2d ago against content hash cc2449cc54f3, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

with-deno scanned grade A with 1 finding 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 2d 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.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

async fetch(request) {
Origin

Copies of this mod

1 near-identical copy found in the catalogue:

  • with-deno — 100% identical, 33 lines differ
.cursor/rules/with-deno.mdc · 558 lines

How it starts

The opening of the file, as written. The whole thing — 558 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Deno 2.0 Project Best Practices, Guidelines, Standards, and Rules

This project uses the latest Deno 2 and any code you generate or review should adhere to all of the information below unless you've been explcitly asked to ignore parts or all of these guidelines.

1) Deno Concepts, Methods, Usage, and Project Design Patterns

Native Deno Methods and Classes

  • Environment Variables: Deno.env.get Deno.env.set
  • Console and Logging: Console.table, Deno.inspect
  • File System: Deno.chown, Deno.chmod, Deno.create, Deno.mkdir, Deno.realpath, Deno.remove, Deno.rename, Deno.umask, Deno.utime, Deno.watchFs, Deno.writeTextFile, Deno.stat
  • Networking: Deno.connect, Deno.connectQuic, Deno.connectTls, Deno.listen, Deno.listenDatagram, Deno.listenTls, Deno.networkInterfaces, Deno.resolveDns, Deno.startTls
  • Runtime: Deno.addSignalListener, Deno.bench, Deno.chdir, Deno.chmod, Deno.chmodSync, Deno.chown, Deno.chownSync, Deno.consoleSize, Deno.copyFile, Deno.copyFileSync, Deno.create, Deno.createHttpClient, Deno.createSync, Deno.cron, Deno.cwd, Deno.dlopen, Deno.execPath, Deno.exit, Deno.gid, Deno.hostname, Deno.inspect, Deno.kill, Deno.link, Deno.linkSync, Deno.loadavg, Deno.lstat, Deno.lstatSync, Deno.makeTempDir, Deno.makeTempDirSync, Deno.makeTempFile, Deno.makeTempFileSync, Deno.memoryUsage, Deno.mkdir, Deno.mkdirSync, Deno.open, Deno.openKv, Deno.openSync, Deno.osRelease, Deno.osUptime, Deno.refTimer, Deno.removeSignalListener, Deno.startTls, Deno.stat, Deno.statSync, Deno.systemMemoryInfo, Deno.uid, Deno.unrefTimer, Deno.utime, Deno.utimeSync, Deno.version
  • Process and Commands: CRITICAL: ALWAYS USE Deno.command. There is also Deno.ChildProcess. Deno Documentation - Deno.command

Full Documentation On Deno Namespace APIs

Read the full file on GitHub · 558 lines

Changes

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.

  1. 2d ago First seen · 558 lines · 0 tokens per session scan A cc2449cc54f3

Subscribe to this mod's changes

with-deno is a cursor rule published in the GitHub repository zackiles/deno-kit (3 stars, last pushed 5mo ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 10,350 tokens. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.