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 anhnguyen0905/codex-mcp --skill design-fundamentalsgit clone --depth 1 https://github.com/anhnguyen0905/codex-mcpWrote 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/anhnguyen0905/codex-mcp/design-fundamentals)<a href="https://agentmods.dev/skills/anhnguyen0905/codex-mcp/design-fundamentals"><img src="https://agentmods.dev/badge/skills/anhnguyen0905/codex-mcp/design-fundamentals/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/anhnguyen0905/codex-mcp/design-fundamentals"><img src="https://agentmods.dev/badge/skills/anhnguyen0905/codex-mcp/design-fundamentals.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 | $0.00096 | $0.00757 |
| Opus 5 | $0.00048 | $0.00378 |
| Sonnet 5 | $0.00019 | $0.00151 |
| Haiku 4.5 | $0.00010 | $0.00076 |
Grade A, and why
design-fundamentals 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 11d 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 — 49 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Design Fundamentals — Agent Instructions
Universal design principles that define why patterns work, how to apply them correctly, and what accessibility requirements are non-negotiable. These are timeless, design-system-agnostic foundations that apply to every surface regardless of vertical or workflow phase.
Load order
Read these files after loading the design system (SKILL.md / DESIGN.md + token modules). The design system tells you what token to use; these files explain why that decision is correct and how to avoid common principle violations.
Module index
| File | Purpose |
|---|---|
| ui-principles.md | Universal visual design principles — hierarchy, layout rhythm, typography placement, color theory, depth & layering, interaction design, responsive adaptation, component behavior |
| spacing-principles.md | Spacing-specific principles — 4-point grid, proximity grouping, inner vs outer gaps, vertical and horizontal rhythm, heading→paragraph spacing, section and component spacing tiers |
| ux-principles.md | Interaction & control principles — 30 UX laws, button/control state contracts (9 states), hover/active technique palettes, touch targets, cognitive load, feedback loops |
| typography-principles.md | Typography-specific principles — type system foundations, scale & modular ratios, readability & measure, accessibility, responsive type, brand tone expression through type |
| accessibility.md | WCAG 2.1/2.2 compliance — contrast ratios, color-as-information rules, focus visibility, keyboard navigation, motion safety, target sizes, text spacing, semantic structure, ARIA |
What these files are NOT
These files do not define:
- Workflow phases (think → build → check → ship) — see
skills/vertical/SKILL.md - Quality gates or audits — see
skills/vertical/inspect.md,review.md,preflight.md - Anti-pattern catalogs — see
skills/vertical/anti-patterns.md - Industry-specific content — see
skills/vertical/team-social-saas.md - Design tokens or component specs — see
skills/design-system/SKILL.md
What ships with it
5 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.
- 11d ago First seen · 49 lines · 96 tokens per session scan A b17634b25dbc
design-fundamentals is a skill published in the GitHub repository anhnguyen0905/codex-mcp (3 stars, last pushed yesterday), licensed MIT. It adds 96 tokens to every session and 757 once invoked, about $0.0005 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 2026-08-31.
Other skills, from other repositories
webgl-holographic-foil
A self-contained WebGL2 hero: thin-film interference over a crushed-foil surface whose palette shifts with the viewing angle; move the cursor to tilt the film.
html-ppt-hermes-cyber-terminal
OpenDesign + BYOK: choosing and wiring your own model, hands-on — cost, quality, and the routing decision. Built as a decision-grade AI literacy deck for engineers, IT, applied-AI teams.
html-ppt-taste-brutalist
16:9 HTML deck in tactical-telemetry / CRT-terminal taste. Deactivated-CRT charcoal slides, white-phosphor monospace, hazard-red accent, scanline overlay, ASCII syntax, density over decoration. Distilled from Leonxlnx/taste-skill brutalist-skill (Tactical Telemetry mode).
visual-ralph
Visual Ralph orchestration for frontend UI from generated references, static references, or live URL targets, using $ultragoal with built-in visual verdict and pixel-diff evidence until the implementation matches and leaves a reproducible design system.
accessibility
Consolidated accessibility skill entrypoint for WCAG 2.2, ARIA Authoring Practices, cognitive accessibility, Section 508, EN 301 549, design intent verification, and the Accessibility Planner workflow.
make-resume
A Chinese-language tool for creating editable HTML resumes that can be changed in a browser and printed to PDF. It uses available resume templates when they are installed and otherwise provides a simpler fallback.