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html-effectiveness

html-effectiveness is a skill for Claude Code from ANcpLua/ancplua-claude-plugins. It costs 242 tokens per session (2,306 once invoked), scanned A, original, MIT.

A skill that creates a self-contained HTML file for reports and other structured outputs instead of returning a long block of plain text.

In plain words
What is it for?
Use it for reports, dashboards, triage boards, design documents, code reviews, flowcharts, slide decks, postmortems, and implementation plans.
Why use it?
HTML can show layout, spatial relationships, and interactive elements that are difficult to represent in ordinary markdown.

Skill for Claude Code

Written for Claude Code: ${CLAUDE_PLUGIN_ROOT} variable. Also seen: mentions Claude Code.

Runs only inside its plugin — its command needs a path that Claude Code sets for a plugin’s own hooks and for nothing else. Install the plugin, not this.

Part of the html-effectiveness plugin — 1 skill shipped together

not rated 6repo 3d ago A scan 242 tokens original MIT

Good fit Use it for reports, dashboards, triage boards, design documents, code reviews, flowcharts, slide decks, postmortems, and implementation plans.

Compare 6 skills from other repositories ↓
View source ↗ ANcpLua/ancplua-claude-plugins
Install

Getting it into your agent

This one installs as part of its plugin. Adding the marketplace and installing the plugin brings it with everything else the plugin ships.

Claude Code
/plugin marketplace add ANcpLua/ancplua-claude-plugins
Claude Code
/plugin install html-effectiveness

Made for: Claude Code.

Or install html-effectiveness, the plugin that ships this one along with the rest of its 1 skill.

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-effectiveness

README.md
[![agentmods](https://agentmods.dev/badge/skills/ancplua/ancplua-claude-plugins/html-effectiveness/github.svg)](https://agentmods.dev/skills/ancplua/ancplua-claude-plugins/html-effectiveness)
Your own site
<a href="https://agentmods.dev/skills/ancplua/ancplua-claude-plugins/html-effectiveness"><img src="https://agentmods.dev/badge/skills/ancplua/ancplua-claude-plugins/html-effectiveness/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 html-effectiveness

Your own site · 80×15
<a href="https://agentmods.dev/skills/ancplua/ancplua-claude-plugins/html-effectiveness"><img src="https://agentmods.dev/badge/skills/ancplua/ancplua-claude-plugins/html-effectiveness.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 242 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,306 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 $0.00242 $0.02306
Opus 5.5 $0.00097 $0.00922
Sonnet 5.5 $0.00048 $0.00461
Haiku 4.5 $0.00024 $0.00231

Measured 1mo ago against content hash d6951c8f51c3, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

html-effectiveness 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 1mo 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/html-effectiveness/skills/html-effectiveness/SKILL.md · 94 lines

How it starts

The opening of the file, as written. The whole thing — 94 lines — stays where its author put it; the contents beside it link to each section on GitHub.

html-effectiveness

Based on Thariq Shihipar's html-effectiveness repo. He works on Claude Code at Anthropic; the philosophy: agents producing HTML files instead of markdown walls because HTML carries spatial information and interaction that markdown flattens.

Canonical source — vendored in-tree

The 20 canonical patterns ship with this plugin as standalone .html files under ${CLAUDE_PLUGIN_ROOT}/skills/html-effectiveness/references/patterns/ (one per pattern.file, e.g. 01-exploration-code-approaches.html … 20-editor-prompt-tuner.html). No clone, no network, no external setup — the plugin carries its own source of truth and works on any machine. They are the upstream reference (Apache-2.0, see references/patterns/UPSTREAM-LICENSE): read them to learn the pattern, then write a new file with the user's data into the user's project area (default: ~/<task>/<slug>.html or alongside related artifacts) — never edit the vendored references in place.

Decision protocol

  1. Load the routing data. Read references/patterns.json from this skill folder. It contains 20 canonical patterns and a decision_tree mapping user-intent phrases (English + German + semantic) to use_pattern IDs. The triggering_principles block at the top tells you HOW to match (fuzzy, multilingual, typo-tolerant, intent-based — not literal).

  2. Match user intent. Scan the user's request for semantic fit with any entry in decision_tree. Match on intent regardless of language, case, or typos. If multiple patterns fit, pick the one whose key_pattern field most closely describes the data structure the user has. If still ambiguous, prefer the more interactive pattern (editor > report > diagram).

  3. Study the canonical source. Open ${CLAUDE_PLUGIN_ROOT}/skills/html-effectiveness/references/patterns/<pattern.file> and read it end-to-end. Don't paraphrase the pattern — internalize the HTML structure, CSS tokens, JS interaction code, and copy-button mechanism. Reuse the same eyebrow / h1 / sub / sticky-toolbar / column / card markup so the output feels like one family.

Read the full file on GitHub · 94 lines

Files

What ships with it

24 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.

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. 1mo ago First seen · 94 lines · 242 tokens per session scan A d6951c8f51c3

Subscribe to this mod's changes

html-effectiveness is a skill published in the GitHub repository ANcpLua/ancplua-claude-plugins (6 stars, last pushed 3d ago), licensed MIT. It adds 242 tokens to every session and 2,306 once invoked, about $0.0010 per session on Opus 5.5. 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 2026-10-01.

Design and UXWriting and docsancplua-fleet
Related

html-effectiveness compared with skills from other repositories

html-effectiveness next to 6 skills from other repositories
ModTypeStarsLast pushLicenceScanTokensWorks with
html-effectivenessANcpLua/ancplua-claude-pluginsSkill63d agoMITA242Claude Code
webgl-holographic-foilnexu-io/open-designSkill107ktodayApache-2.0A41Claude Code, Codex
html-ppt-hermes-cyber-terminalnexu-io/open-designSkill107ktodayApache-2.0A53Claude Code, Codex
html-ppt-taste-brutalistnexu-io/open-designSkill107ktodayApache-2.0A78Claude Code, Codex
visual-ralphYeachan-Heo/oh-my-codexSkill34k2d agoMITA52Codex
glance-canonical-layoutsandroid/skillsSkill10kyesterdayApache-2.0A56Claude Code
accessibilitymicrosoft/hve-coreSkill1.6ktodayMITA47Claude Code