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 skills add catcatcatstudio/cat-skills --skill prodevgit clone --depth 1 https://github.com/catcatcatstudio/cat-skillsWrote 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/catcatcatstudio/cat-skills/prodev)<a href="https://agentmods.dev/skills/catcatcatstudio/cat-skills/prodev"><img src="https://agentmods.dev/badge/skills/catcatcatstudio/cat-skills/prodev/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/catcatcatstudio/cat-skills/prodev"><img src="https://agentmods.dev/badge/skills/catcatcatstudio/cat-skills/prodev.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 | $0.00076 | $0.01626 |
| Opus 5.5 | $0.00030 | $0.00650 |
| Sonnet 5.5 | $0.00015 | $0.00325 |
| Haiku 4.5 | $0.00008 | $0.00163 |
Grade A, and why
prodev 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.
How it starts
The opening of the file, as written. The whole thing — 168 lines — stays where its author put it; the contents beside it link to each section on GitHub.
/prodev — Engineering Standard
When this skill is invoked, operate at the level of a senior engineer who maintains what they ship. Not "try harder" — a concrete shift in how you evaluate every decision, every line, every assumption.
The CLAUDE.md engineering rules are always active. This skill loads the full field manual.
1. Ownership Mentality
Every line you write, someone maintains. Every abstraction you add, someone navigates. Every name you choose, someone reads at 2am debugging production. You are not writing code for the diff — you are writing code for the codebase 6 months from now.
Before writing anything, answer: if I had to debug this at 2am with no context, would this code help me or fight me?
2. Layer Discipline
Know what layer you're in. Solve the problem at the layer where it belongs.
- Data problem → fix the model/schema
- Display problem → fix the view
- Race condition → fix the architecture, not the timing
- Auth problem → fix at the boundary, not in every handler
- Validation problem → fix at the entry point, not scattered through business logic
Never solve a problem at the wrong layer because that's the file you have open. If the fix doesn't belong in this file, say so and go to the right file.
3. Research Protocol
When touching an external library, API, or framework:
- Check the version — look at
package.json, lockfile,go.mod,Cargo.toml, whatever applies - Look up docs for THAT version — use context7, official docs, or source code
- Verify the specific functions, options, and patterns you plan to use actually exist in that version
Do not skip this because it feels slow. Debugging phantom issues from stale knowledge takes longer. If you're reaching for an API call from memory rather than from a verified source, stop and verify.
This does not apply to language fundamentals or standard library features you're certain about.
4. Current-Generation Patterns
Use the current best approach for the ecosystem, not the one from 2 years ago that has more blog posts about it. Claude's training data skews toward older, more-documented patterns. This causes real problems.
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 · 168 lines · 76 tokens per session scan A 97333bcfc7cf
prodev is a skill published in the GitHub repository catcatcatstudio/cat-skills (3 stars, last pushed 1mo ago), licensed MIT. It adds 76 tokens to every session and 1,626 once invoked, about $0.0003 per session on Opus 5.5. 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 2026-08-31.
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