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 Bigrapb/Concreto --skill skillgit clone --depth 1 https://github.com/Bigrapb/ConcretoWrote 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/bigrapb/concreto/skill)<a href="https://agentmods.dev/skills/bigrapb/concreto/skill"><img src="https://agentmods.dev/badge/skills/bigrapb/concreto/skill/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/bigrapb/concreto/skill"><img src="https://agentmods.dev/badge/skills/bigrapb/concreto/skill.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 | $0.00093 | $0.01509 |
| Opus 5.5 | $0.00037 | $0.00604 |
| Sonnet 5.5 | $0.00019 | $0.00302 |
| Haiku 4.5 | $0.00009 | $0.00151 |
Grade A, and why
concreto 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 — 166 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Advanced design intelligence for production-grade frontend interfaces. Deterministic rules, ML-enhanced detection, and comprehensive design guidance.
Setup
REQUIRED BEFORE PROCEEDING:
- Run
node {{scripts_path}}/context.mjsonce per session. If you've seen its output, skip. The script outputs PRODUCT.md (and DESIGN.md when present). If output reportsNO_PRODUCT_MD, stop and runinitbefore continuing. - If user invoked a sub-command, read
reference/<command>.mdnext. Non-optional. The reference defines the command flow. - Read at least one project file (CSS/tokens/theme/component). Required even with a sub-command reference loaded. Use existing patterns.
- Read the matching register reference:
brand(marketing, landing, portfolio) →reference/brand.mdproduct(app UI, dashboard, tool) →reference/product.mdPick by: task cue → surface in focus →registerin PRODUCT.md.
- If no committed brand colors exist, run
node {{scripts_path}}/palette.mjsfor color seed and composition guidance. Use OKLCH throughout.
Core Principles
Production-Grade Output
Ship complete, polished implementations. Not prototypes. Not starting points. Every page, component, and interaction is battle-tested.
The Test: Would You Sign It?
If you wouldn't put your name on the code, it's not done. This means:
- Zero warnings in browser console
- No placeholder content
- Responsive at every breakpoint
- Keyboard navigable
- Screen reader tested
Design Rules
Color
[A01-CRITICAL] Verify contrast ≥4.5:1 for body text
[A02-CRITICAL] Verify contrast ≥3:1 for large text
[V01-HIGH] Never gray text on colored backgrounds
[V02-MEDIUM] Tint neutrals toward brand hue, not warmth-default
[V03-LOW] Document color strategy before picking colors
Color Strategy Commitment Axis:
- Restrained: Tinted neutrals + one accent ≤10%
- Committed: One color covers 30-60%
- Full Palette: 3-4 named roles
- Drenched: Surface IS the color
What ships with it
3 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.
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 · 166 lines · 93 tokens per session scan A 7c4ca2e81ae7
concreto is a skill published in the GitHub repository Bigrapb/Concreto (2 stars, last pushed 4mo ago), licensed MIT. It adds 93 tokens to every session and 1,509 once invoked, about $0.0004 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
daisyui-colors
Color rules that you must use with daisyUI 5.
daisyui-config
Configuration options for daisyUI 5.
designlang-tokens
Use when styling UI for cal.com — references the extracted design system tokens instead of inventing colors, spacing, or typography.
ui-components
UI component library patterns for shadcn/ui and Radix Primitives. Use when building accessible component libraries, customizing shadcn components, using Radix unstyled primitives, or creating design system foundations.
s2-docs
Look up Spectrum 2 (S2) component documentation, design guidelines, and usage patterns when building with React Spectrum or Spectrum Web Components. Use when the user mentions Spectrum, S2, React Spectrum, RSP, Spectrum Web Components, or SWC, or names a Spectrum component (Button, Picker, ComboBox, TextField…
handoff-spec
Write the implementation handoff — measurements, behaviours, assets, states, and edge cases. Use when engineering picks up the work. For verifying the result afterwards use design-qa-checklist; for reusable library components use component-spec (design-systems).