Getting it into your agent
It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.
git clone --depth 1 https://github.com/j4flmao/agent-skillsnpx agentmods add skills/j4flmao/agent-skills/denoWrote 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/skills/j4flmao/agent-skills/deno)<a href="https://agentmods.dev/skills/j4flmao/agent-skills/deno"><img src="https://agentmods.dev/badge/skills/j4flmao/agent-skills/deno/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/skills/j4flmao/agent-skills/deno"><img src="https://agentmods.dev/badge/skills/j4flmao/agent-skills/deno.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
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 | $0.00068 | $0.04740 |
| Opus 5 | $0.00034 | $0.02370 |
| Sonnet 5 | $0.00014 | $0.00948 |
| Haiku 4.5 | $0.00007 | $0.00474 |
Grade A, and why
deno 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 9d 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.
How it starts
The opening of the file, as written. The whole thing — 594 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Deno
Purpose
Build secure-by-default TypeScript applications with Deno runtime — permissions model, module system, standard library, Fresh framework, and deployment.
Agent Protocol
Trigger
User request includes: Deno, deno deploy, deno fresh, deno std, deno run, deno compile, deno test, deno fmt, deno lint, deno task, deno.json, import_map.json, TypeScript runtime, Fresh framework, deno.land.
Input Context
- Runtime (Deno, Deno Deploy, self-hosted)
- Framework (Fresh, Oak, Hono, bare)
- Permissions required (net, read, write, env, ff, run)
- Module strategy (deno.land/x, npm, JSR)
Output Artifact
Project setup, permission flags, module imports, Fresh route structure, deployment config.
Response Format
Produce artifact directly. No preamble, no postamble, no explanations. No filler, no hedging, no transitions. Strip articles a/an/the where unambiguous. Compress output — why use many token when few do trick.
Completion Criteria
- Deno.json config with tasks, lint, fmt, permissions
- Import map or deno.json imports configured
- Fresh project structure with routes and islands
- Deno Deploy or Docker deployment config
Max Response Length
4096 tokens
Architecture Decision Trees
Framework Selection: Fresh vs Oak vs Hono vs Bare
| Criterion | Fresh | Oak | Hono | Bare (std/http) |
|---|---|---|---|---|
| SSR + Islands | Yes (Preact) | No | No | No |
| REST API | Heavy (file-based) | Best | Best | Minimal |
| Edge deployment | Deno Deploy native | Compatible | Compatible | Compatible |
| Middleware model | Route-level | Context pipeline | Express-like | Manual |
| Type safety | Partial | Generic params | Full (TypeBox/Zod) | Manual |
| npm compat | Via JSR | Via JSR | Built-in | Via JSR |
Decision: routes/ file-based routing → Fresh. REST API w/ middleware → Oak. TypeScript-first w/ validation → Hono. Minimal/single-purpose → std/http.
Module Import Strategy: deno.land/x vs JSR vs npm
What ships with it
13 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
- oak/references/deno-runtime-guide.md 3.2 KB
- oak/references/oak-middleware.md 4.9 KB
- oak/references/oak-performance.md 6.6 KB
- oak/references/oak-routing-deployment.md 6.4 KB
- oak/references/oak-setup.md 2.8 KB
- oak/references/oak-testing.md 5.0 KB
- oak/SKILL.md 16 KB
- references/deno-advanced.md 12 KB
- references/deno-deployment.md 4.5 KB
- references/deno-essentials.md 7.9 KB
- references/deno-fundamentals.md 11 KB
- references/deno-runtime.md 3.9 KB
- references/fresh-framework.md 8.9 KB
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.
- 9d ago First seen · 594 lines · 68 tokens per session scan A 5fa9c276687d
deno is a skill published in the GitHub repository j4flmao/agent-skills (22 stars, last pushed 2d ago), licensed MIT. It adds 68 tokens to every session and 4,740 once invoked, about $0.0003 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.
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