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 agentmods add skills/the-sid-dani/second-brain-os/design-web-prototypenpx skills add the-sid-dani/second-brain-os --skill design-web-prototypegit clone --depth 1 https://github.com/the-sid-dani/second-brain-osWrote 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/the-sid-dani/second-brain-os/design-web-prototype)<a href="https://agentmods.dev/skills/the-sid-dani/second-brain-os/design-web-prototype"><img src="https://agentmods.dev/badge/skills/the-sid-dani/second-brain-os/design-web-prototype.svg" alt="Measured on agentmods" 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 | $0.00083 | $0.00951 |
| Opus 5 | $0.00042 | $0.00476 |
| Sonnet 5 | $0.00017 | $0.00190 |
| Haiku 4.5 | $0.00008 | $0.00095 |
Grade A, and why
design-web-prototype 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 4d 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.
This is a copy
88% identical to web-prototype — 25 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 77 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Web Prototype Skill
Produce a single, self-contained HTML prototype using the bundled seed and layout library — not by writing CSS from scratch. The seed already encodes good defaults (typography, spacing, accent budget). Your job is to compose it.
Resource map
web-prototype/
├── SKILL.md ← you're reading this
├── assets/
│ └── template.html ← seed: tokens + class system + chrome (READ FIRST)
└── references/
├── layouts.md ← 8 paste-ready section skeletons
└── checklist.md ← P0/P1/P2 self-review
Workflow
Step 0 — Pre-flight (do this once before writing anything)
- Read
assets/template.htmlend-to-end — at minimum through the<style>block. The class inventory at the top ofreferences/layouts.mdlists every class that must be defined there; if one is missing, add it to<style>rather than re-defining it inline on every section. - Read
references/layouts.mdso you know which section skeletons exist. Don't write a section type that isn't covered — pick the closest layout and adapt. - Read the active DESIGN.md (already injected into your system prompt). Map its colors to the six
:rootvariables in the seed; don't introduce new tokens.
Step 1 — Copy the seed
Copy assets/template.html to the project root as index.html. Replace the six :root variables with the active design system's tokens. Replace the page <title> and the topnav brand.
Step 2 — Plan the section list
Pick layouts before writing copy. Default rhythms (from layouts.md):
| Page kind | Default rhythm |
|---|---|
| Landing | 1 hero → 3 features → 4 stats or 5 quote → custom split → 6 cta |
| Marketing / editorial | 1 hero-center → 7 log list → 6 cta |
| Pricing | 1 hero-center → 8 comparison table → 6 cta |
| Docs index | 1 hero-center → 7 log list (sections of docs) → 6 cta |
State the chosen list in one sentence to the user before writing — they can redirect cheaply now and not after 200 lines of HTML.
What ships with it
4 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.
- 4d ago First seen · 77 lines · 83 tokens per session scan A 85b6df080a86
design-web-prototype is a skill published in the GitHub repository the-sid-dani/second-brain-os (2 stars, last pushed 29d ago), licensed MIT. It adds 83 tokens to every session and 951 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. It is 88% identical to web-prototype, differing in 25 lines, and is treated as a copy.
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