html-prototyper

html-prototyper is an agent for Claude Code from tmchow/tmc-marketplace. It costs 49 tokens per session (205 once invoked), scanned A, original, MIT.

A hidden helper that turns a complete design variation specification into one self-contained HTML file.

In plain words
What is it for?
It creates HTML prototypes when the design-exploration process supplies the layout, content, controls, styling rules, and output path.
Why use it?
It handles the file-writing part of design exploration, but it is not meant to be called on its own.

Agent for Claude Code

Written for Claude Code: background in frontmatter. Also seen: model in frontmatter.

Part of the iterative-engineering plugin — 12 skills, 18 agents shipped together

Good fit It creates HTML prototypes when the design-exploration process supplies the layout, content, controls, styling rules, and output path.

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Install with agentmods
npx agentmods add agents/tmchow/tmc-marketplace/html-prototyper
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.

Clone the repo
git clone --depth 1 https://github.com/tmchow/tmc-marketplace

Made for: Claude Code.

Or install iterative-engineering, the plugin that ships this one along with the rest of its 12 skills, 18 agents.

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 html-prototyper

README.md
[![agentmods](https://agentmods.dev/badge/agents/tmchow/tmc-marketplace/html-prototyper.svg)](https://agentmods.dev/agents/tmchow/tmc-marketplace/html-prototyper)
Your own site
<a href="https://agentmods.dev/agents/tmchow/tmc-marketplace/html-prototyper"><img src="https://agentmods.dev/badge/agents/tmchow/tmc-marketplace/html-prototyper.svg" alt="Measured on agentmods" height="20"></a>
Per session 49 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 205 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.
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 $0.00049 $0.00205
Opus 5 $0.00024 $0.00102
Sonnet 5 $0.00010 $0.00041
Haiku 4.5 $0.00005 $0.00020

Measured 8d ago against content hash 24bd8cf273af, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

html-prototyper 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 8d 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.

plugins/iterative-engineering/agents/html-prototyper.md · 23 lines

What it actually says

HTML Prototyper

You generate a single HTML file from a complete specification. One file, one turn, done.

Behavior

The prompt contains everything — variation brief, layout, data, and controls. Do not read files, search, or ask questions. Write the HTML file to the specified path. No commentary before or after. Stop after writing.

The design-prototyping skill loaded into your context has the complete file format, control schema, styling rules, and pre-output checklist. Follow it exactly.

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. 8d ago First seen · 23 lines · 49 tokens per session scan A 24bd8cf273af

Subscribe to this mod's changes

html-prototyper is an agent published in the GitHub repository tmchow/tmc-marketplace (22 stars, last pushed 6mo ago), licensed MIT. It adds 49 tokens to every session and 205 once invoked, about $0.0002 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.