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 mehdiforoozandeh/crux --skill evolve-cruxgit clone --depth 1 https://github.com/mehdiforoozandeh/cruxWrote 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/mehdiforoozandeh/crux/evolve-crux)<a href="https://agentmods.dev/skills/mehdiforoozandeh/crux/evolve-crux"><img src="https://agentmods.dev/badge/skills/mehdiforoozandeh/crux/evolve-crux/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/mehdiforoozandeh/crux/evolve-crux"><img src="https://agentmods.dev/badge/skills/mehdiforoozandeh/crux/evolve-crux.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 | $0.00218 | $0.02665 |
| Opus 5.5 | $0.00087 | $0.01066 |
| Sonnet 5.5 | $0.00044 | $0.00533 |
| Haiku 4.5 | $0.00022 | $0.00266 |
Grade A, and why
evolve-crux 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 — 191 lines — stays where its author put it; the contents beside it link to each section on GitHub.
evolve-crux — ship a change to crux, rigorously
This skill is for working on crux the tool (your clone of the crux repo), not on a research project that uses crux. It carries one change — a new capability or a fix for something crux keeps getting wrong — through a strictly gated arc:
ideate → build → validate → ship
Each stage has an exit criterion; you do not advance until it's met. The arc is the
same whether the change is a one-line bug fix or a .spec/ epic — only the ceremony scales.
Who's driving (contributor-always)
Assume the person evolving crux is not the maintainer. Because crux ships this skill to its users, everyone runs the same path and ends at a pull request — no auto-detection of who you are, no privileged branch. The maintainer is just the contributor who can self-merge their own PR, plus a small, separate release step (below). This keeps one code path and makes third-party PRs first-class.
Work in a dedicated session inside your crux clone (a fresh chat, not the project you
were researching). No clone yet — e.g. you installed the skills via npx skills add?
git clone https://github.com/mehdiforoozandeh/crux first. For a large build you may
dispatch a worktree sub-agent, but the default is the main thread.
1 · Ideate → a signed-off PRD ◆
Ideation ends when there is a PRD the human has approved — not before any code. Reach
it by a pingpong / grill-me back-and-forth (surface one decision at a time; don't dump
options): what exactly are we adding or fixing, why, the design choice, and — load-bearing
— the acceptance criteria (the concrete checks that later become the validation
gate). Pre-registering "how we'll know it worked" is what makes validate enforceable
instead of vibes.
The PRD scales to the change:
- Bug ("crux keeps mis-splitting inline parens") → a one-line PRD: the wrong behavior, the correct behavior, and the acceptance criterion = a failing selftest that asserts the correct behavior.
- Feature / backlog epic (UI, wiki, autoresearch) → a full grilled PRD (skeleton below).
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 · 191 lines · 218 tokens per session scan A d22b45761a37
evolve-crux is a skill published in the GitHub repository mehdiforoozandeh/crux (18 stars, last pushed today), licensed MIT. It adds 218 tokens to every session and 2,665 once invoked, about $0.0009 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.
Other skills, from other repositories
ab-testing
Use when designing or analyzing a controlled experiment — falsifiable hypothesis, sample size from an MDE, reading significance/CI/power, CUPED, or rescuing tests that won't go significant. NOT recurring metric tracking (that is analytics), NOT north-star/KPI trees (that is kpi-framework), NOT projecting metrics…
research-manager
Use this when starting a new research project or managing a complex, multi-step research workflow.
academic-writing
You must use this when producing any research prose — literature reviews, syntheses, analyses, methodology descriptions, discussion sections, abstracts, or any written output intended for an academic audience.
ab-testing-ecommerce
Run controlled experiments on product pages, checkout flows, and pricing to find what converts best using statistical significance testing.
systematic-review
You must use this when conducting PRISMA-standard systematic reviews, protocol development, or Risk of Bias assessment.
hypothesis-testing
You must use this when formulating testable hypotheses, designing experimental controls, or defining falsification criteria.