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 Kevin-Liu-01/Agent-Machines --skill font-switcher-dev-toolgit clone --depth 1 https://github.com/Kevin-Liu-01/Agent-MachinesWrote 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/kevin-liu-01/agent-machines/font-switcher-dev-tool)<a href="https://agentmods.dev/skills/kevin-liu-01/agent-machines/font-switcher-dev-tool"><img src="https://agentmods.dev/badge/skills/kevin-liu-01/agent-machines/font-switcher-dev-tool/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/kevin-liu-01/agent-machines/font-switcher-dev-tool"><img src="https://agentmods.dev/badge/skills/kevin-liu-01/agent-machines/font-switcher-dev-tool.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
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 | $0.00086 | $0.01485 |
| Opus 5 | $0.00043 | $0.00743 |
| Sonnet 5 | $0.00017 | $0.00297 |
| Haiku 4.5 | $0.00009 | $0.00148 |
Grade A, and why
font-switcher-dev-tool scanned grade A with 1 finding 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 12d 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.
Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
curl -sL "https://fonts.googleapis.com/css2?family=FONT+NAME:[email protected]&display=swap" \ How it starts
The opening of the file, as written. The whole thing — 182 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Font Switcher Dev Tool
When to Use
- User wants to preview/compare multiple fonts across an app
- User drops a folder of font files and wants them wired up
- User says "font switcher", "font selector", "try these fonts", "toggle fonts"
- User wants to evaluate typefaces before committing to one
Architecture
The font switcher works by overriding a single CSS custom property on <html>:
--font-active → picked up by --font-sans → applied to body
No re-renders. No class swapping. One CSS variable update per font change.
File structure:
public/fonts/<family-slug>/ ← font files (Regular + Bold minimum)
src/app/fonts.css ← @font-face declarations
src/lib/fonts.ts ← font metadata constants + helpers
src/contexts/FontContext.tsx ← provider with localStorage persistence
src/components/FontSelector.tsx ← floating UI (bottom-right, grouped, random)
Step 1: Copy Font Files
Organize by family in public/fonts/. Use kebab-case directory names.
mkdir -p public/fonts/<family-slug>
cp "/path/to/FontName-Regular.otf" public/fonts/<family-slug>/
cp "/path/to/FontName-Bold.otf" public/fonts/<family-slug>/
Include at minimum Regular (400) and Bold (700) weights. For variable fonts, one file covers all weights.
Step 2: Download Google Fonts (if needed)
Google Fonts only returns woff2 with a modern user agent:
# Get the CSS with woff2 URLs
curl -sL "https://fonts.googleapis.com/css2?family=FONT+NAME:[email protected]&display=swap" \
-H "User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36"
# Find the Latin subset src URL, then download it
curl -L -o public/fonts/<slug>/FontName-Variable-Latin.woff2 "https://fonts.gstatic.com/s/..."
Verify the downloaded file is >1KB (tiny files = redirect, not a font).
Step 3: Generate @font-face CSS
Create src/app/fonts.css:
@font-face {
font-family: "Font Name";
src: url("/fonts/<slug>/FontName-Regular.otf") format("opentype");
font-weight: 400;
font-display: swap;
}
@font-face {
font-family: "Font Name";
src: url("/fonts/<slug>/FontName-Bold.otf") format("opentype");
font-weight: 700;
font-display: swap;
}
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.
- 12d ago First seen · 182 lines · 86 tokens per session scan A 99c624b241c7
font-switcher-dev-tool is a skill published in the GitHub repository Kevin-Liu-01/Agent-Machines (29 stars, last pushed today), licensed MIT. It adds 86 tokens to every session and 1,485 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
Other skills, from other repositories
21st-ui
Find, install, and generate UI with 21st.dev. Use when the user asks for a UI component (pricing table, hero, navbar, dashboard, form, etc.), wants design inspiration, needs a brand logo as an SVG component, or wants to generate new UI from a prompt.
service-portal-pages
The container side of Service Portal — the spportal → sppage → sprow → spcolumn → spinstance hierarchy, why widget options belong on the instance and not the widget, cloning pages, and what is theme (sptheme, spbrand, spcss) rather than page.
cross-browser-typography-qa
Use this skill when web text looks clipped, flattened, wrapped incorrectly, misaligned, or materially different between Chromium and WebKit/Safari. Treat text rendering as both a geometry problem and a visual paint problem: passing DOM bounds does not prove that every glyph is intact.
skill-export-page
Skill "skill-export-page" from theYahia/WWmcp, covering /skill-export-page, algorithm and examples.
theme
Apply brand and visual direction in a Mantle application using its repo-owned theme and UI contracts.
design-taste-frontend
Anti-slop frontend skill for landing pages, portfolios, and redesigns. The agent reads the brief, infers the right design direction, and ships interfaces that do not look templated. Real design systems when applicable, audit-first on redesigns, strict pre-flight check.