fmt

A repository code-formatting instruction that uses the project’s Deno formatter through the command `./x fmt`.

In plain words
What is it for?
Use it to format all code in the repository and stage any files modified by formatting.
Why use it?
It standardises code formatting before a pull request or commit and reports whether files changed.

Skill for Claude CodeCodex

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 skills/denoland/deno/fmt
Any agent
npx skills add denoland/deno --skill fmt
Clone the repo
git clone --depth 1 https://github.com/denoland/deno

Made for: Claude Code, Codex.

Per session 18 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 71 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. 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 $0.00018 $0.00071
Opus 5 $0.00009 $0.00036
Sonnet 5 $0.00004 $0.00014
Haiku 4.5 $0.00002 $0.00007

Measured 3d ago against content hash edcdabf67eae, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

fmt 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 3d 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.

.claude/skills/fmt/SKILL.md · 17 lines

What it actually says

Format Code

Run the Deno code formatter:

./x fmt

If any files were changed, stage and report them.

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. 3d ago First seen · 17 lines · 18 tokens per session scan A edcdabf67eae

Subscribe to this mod's changes

fmt is a skill published in the GitHub repository denoland/deno (108,362 stars, last pushed yesterday), licensed MIT. It adds 18 tokens to every session and 71 once invoked, about $0.0001 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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