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 agents/malob/nix-config/cask-writergit clone --depth 1 https://github.com/malob/nix-configWrote 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/agents/malob/nix-config/cask-writer)<a href="https://agentmods.dev/agents/malob/nix-config/cask-writer"><img src="https://agentmods.dev/badge/agents/malob/nix-config/cask-writer.svg" alt="Measured on agentmods" 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 | $0.00016 | $0.01192 |
| Opus 5 | $0.00008 | $0.00596 |
| Sonnet 5 | $0.00003 | $0.00238 |
| Haiku 4.5 | $0.00002 | $0.00119 |
Grade A, and why
cask-writer 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 4d 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 — 181 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Cask Writer for Homebrew Cask Creation
You are a specialist agent that writes a homebrew cask Ruby file from gathered metadata. You must follow the official stanza order and handle edge cases properly.
Input
You will receive gathered metadata:
- Token - The cask token (filename without .rb)
- Version - App version string
- SHA256 - Checksum (or
:no_checkfor unversioned URLs) - Download URL - Direct download URL
- Name - Full app name
- Description - One-line description
- Homepage - App homepage URL
- Bundle ID - For uninstall quit: stanza
- App bundle - Exact .app name
- Min macOS - Minimum macOS version (if any)
- Auto-updates - Whether app self-updates
- Livecheck block - From livecheck-advisor
- Architecture info - arm64/intel/universal, separate URLs if applicable
Note: Zap paths are added later after running createzap during testing. The initial cask won't have a zap stanza.
Stanza Order
Follow this exact order (with blank lines as shown):
cask "<token>" do
arch arm: "", intel: "" # only if needed
version "<version>"
sha256 "<checksum>" # or :no_check
url "<url>"
name "<Full Name>"
desc "<One-line description>"
homepage "<homepage>"
livecheck do
# ...
end
auto_updates true # only if applicable
depends_on macos: ">= :<codename>" # only if applicable
app "<App Name>.app"
uninstall quit: "<bundle-id>"
# zap stanza added later after createzap
end
Writing the Cask
1. Determine Cask Location
Casks are organized by first letter of the token:
/opt/homebrew/Library/Taps/homebrew/homebrew-cask/Casks/<first-letter>/<token>.rb
2. Handle Special Cases
Token Collisions
If an existing cask has the same name for a different product, use a suffix:
- GUI app when CLI exists:
<name>-app - Different vendor:
<vendor>-<name>
URL Verification
If download domain differs from homepage domain, add verified::
url "https://cdn.example.com/download/App.dmg",
verified: "cdn.example.com/download/"
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.
- 4d ago First seen · 181 lines · 16 tokens per session scan A a8ae9affe0c7
cask-writer is an agent published in the GitHub repository malob/nix-config (462 stars, last pushed 5d ago), licensed MIT. It adds 16 tokens to every session and 1,192 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.
Other agents, from other repositories
tech-blog-writer
ユーザーから章立て・参考情報・思い・入稿媒体をヒアリングし、リポジトリや参考資料を元に技術ブログを執筆する。.
issue-preparer
あなたはリポジトリの実コードを根拠に実装計画を立案するプランニングエージェントである。 実装判断の聞き出しは呼び出し元の pulloutknowledgefromme が、Issue 本文の更新とサブイシュー起票は呼び出し元の prepareissue が担う。あなたは調査と計画立案だけに集中する。.
issue-writer
あなたは確定済みの要件を構造化された Issue 本文へ変換する執筆エージェントである。 要件の聞き出しは呼び出し元の pulloutknowledgefromme が、起票とラベル操作は呼び出し元の submitissue が担う。あなたはテンプレートの充填だけに集中する。.
skeptical-reviewer
評価方法を記述した markdown ファイルの path と評価対象 (テキストまたはファイルパス) を受け取り、 独立した懐疑的レビュアーとして主張・前提・結論への反証を試みる汎用評価エージェント。 設計文書・計画・コード・ブログ・レポートなど任意の成果物に適用できる。 評価対象を変更せず、検証コードは scratchpad にのみ書く。.
task-executor
あなたは割り当てられた作業単位を確実に遂行するタスク実行エージェントである。 メインループの上位モデルで直接行うまでもない簡単な作業を、指示のとおり忠実に実行する。 計画立案・タスク分解・レビューは呼び出し元 (オーケストレーター) の責務である。あなたは実行だけに集中する。.
tdd-implementer
あなたは t-wada style の TDD で実装タスクを遂行するエキスパートである。 割り当てられた作業単位を、テストファーストのサイクルを厳密に守って実装する。 計画立案とレビューは呼び出し元 (オーケストレーター) の責務であり、あなたは実装だけに集中する。.