demo-site-builder

demo-site-builder is a skill for Claude Code from buildfastwithai/gen-ai-experiments. It costs 71 tokens per session (1,183 once invoked), scanned A, original, MIT.

A workflow for building one self-contained HTML demo or landing page that explains and, where possible, demonstrates a GitHub repository. The resulting file works in a browser without a build step or local dependencies.

In plain words
What is it for?
Use it to create offline demo sites, project showcases, landing pages, or interactive explanations based on a repository's documented functionality.
Why use it?
It turns a repository into a portable page that others can open and understand without setting up the project.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the launch-mcp plugin — 4 skills, 1 MCP server shipped together

Good fit Use it to create offline demo sites, project showcases, landing pages, or interactive explanations based on a repository's documented functionality.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/buildfastwithai/gen-ai-experiments/demo-site-builder
Install

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.

Any agent
npx skills add buildfastwithai/gen-ai-experiments --skill demo-site-builder
Clone the repo
git clone --depth 1 https://github.com/buildfastwithai/gen-ai-experiments

Made for: Claude Code.

Or install launch-mcp, the plugin that ships this one along with the rest of its 4 skills, 1 MCP server.

Wrote 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.

agentmods badge for demo-site-builder

README.md
[![agentmods](https://agentmods.dev/badge/skills/buildfastwithai/gen-ai-experiments/demo-site-builder/github.svg)](https://agentmods.dev/skills/buildfastwithai/gen-ai-experiments/demo-site-builder)
Your own site
<a href="https://agentmods.dev/skills/buildfastwithai/gen-ai-experiments/demo-site-builder"><img src="https://agentmods.dev/badge/skills/buildfastwithai/gen-ai-experiments/demo-site-builder/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.

agentmods 80×15 button for demo-site-builder

Your own site · 80×15
<a href="https://agentmods.dev/skills/buildfastwithai/gen-ai-experiments/demo-site-builder"><img src="https://agentmods.dev/badge/skills/buildfastwithai/gen-ai-experiments/demo-site-builder.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 71 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,183 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00071 $0.01183
Opus 5 $0.00036 $0.00592
Sonnet 5 $0.00014 $0.00237
Haiku 4.5 $0.00007 $0.00118

Measured 12d ago against content hash 4d651499cc9c, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

demo-site-builder 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 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.

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.

mcp/servers/launch-mcp/skills/demo-site-builder/SKILL.md · 62 lines

How it starts

The opening of the file, as written. The whole thing — 62 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Demo Site Builder

Turn a repository analysis into ONE self-contained demo.html that a reader can open in any browser and immediately understand what the project does and why it matters. The page both explains and, where feasible, demonstrates the functionality.

Non-negotiables

  • Single file. Everything — HTML, CSS, JS — lives in one demo.html. No build step, no node_modules, no local asset files.
  • Works offline by double-click. It must render fully when opened directly from disk (file://). Only optional enhancements (a web font, a syntax-highlight CDN, an icon set) may load from a CDN, and the page must still look correct if those fail.
  • Grounded in the analysis. Every feature, number, code sample, and claim comes from the analyze_repo output (description, README, languages, topics, stars, commits). Never invent capabilities, benchmarks, or quotes. If the README shows a real usage snippet, reuse it verbatim.
  • No secrets, no live network calls to the user's services. A demo may simulate behavior in-browser, but must not require API keys or hit private endpoints.

Page structure (in order)

  1. Hero — project name, a one-line tagline distilled from the description, 2-4 badges (language, license, stars, latest version if any), and two buttons: "View on GitHub" (links to the repo URL) and a "See it in action" anchor to the demo section.
  2. Problem → Solution — 1-2 short paragraphs: the problem the repo solves and how it solves it. Pulled from the README intro.
  3. Key features — a responsive grid of 3-6 cards, each with an icon/emoji, a title, and one sentence. Only features evidenced by the analysis.
  4. Live demo or walkthrough — the centerpiece:
    • If the repo is a browser-runnable JS/TS library or produces visual/text output that can be reproduced client-side, embed a genuinely interactive widget (inputs → live result) implemented in inline JS.
    • If it is a CLI, backend, or non-browser tool, build a realistic simulated terminal / API playground: the user clicks example commands and sees representative output (clearly labelled "sample output"), driven by canned data taken from the README. Do not fake success of things you cannot actually run.
    • Always label simulated output honestly.
  5. Usage / code example — the real install + minimal usage from the README, in a styled, copy-to-clipboard code block.
  6. Tech stack — languages (with the analyzed percentages) and notable topics as pills.
  7. Footer — repo link, license, "Generated launch demo" note, contributor credit.

Read the full file on GitHub · 62 lines

Files

What ships with it

1 file 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.

Changes

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.

  1. 12d ago First seen · 62 lines · 71 tokens per session scan A 4d651499cc9c

Subscribe to this mod's changes

demo-site-builder is a skill published in the GitHub repository buildfastwithai/gen-ai-experiments (763 stars, last pushed today), licensed MIT. It adds 71 tokens to every session and 1,183 once invoked, about $0.0004 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 2026-08-30.

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