htmlhint

htmlhint is a skill for Claude Code, Codex from managedcode/dotnet-skills. It costs 105 tokens per session (1,109 once invoked), scanned A, original, MIT.

An HTML checker for static web pages and generated HTML files. It looks for structural problems and invalid attributes.

In plain words
What is it for?
Use it on HTML source, built files such as dist output, or a reachable page when checking static markup.
Why use it?
It finds basic HTML mistakes without requiring a full browser, accessibility, or performance audit.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: mentions AGENTS.md.

Good fit Use it on HTML source, built files such as dist output, or a reachable page when checking static markup.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/managedcode/dotnet-skills/htmlhint
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 managedcode/dotnet-skills --skill htmlhint
Clone the repo
git clone --depth 1 https://github.com/managedcode/dotnet-skills

Made for: Claude Code, Codex.

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 htmlhint

README.md
[![agentmods](https://agentmods.dev/badge/skills/managedcode/dotnet-skills/htmlhint/github.svg)](https://agentmods.dev/skills/managedcode/dotnet-skills/htmlhint)
Your own site
<a href="https://agentmods.dev/skills/managedcode/dotnet-skills/htmlhint"><img src="https://agentmods.dev/badge/skills/managedcode/dotnet-skills/htmlhint/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 htmlhint

Your own site · 80×15
<a href="https://agentmods.dev/skills/managedcode/dotnet-skills/htmlhint"><img src="https://agentmods.dev/badge/skills/managedcode/dotnet-skills/htmlhint.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 105 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,109 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 warn 7 Sept 2026
SkillSpector: 2 findings, up to medium

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • medium MCP Rug Pull · line 52
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
  • medium MCP Rug Pull · line 53
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
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 $0.00105 $0.01109
Opus 5 $0.00053 $0.00554
Sonnet 5 $0.00021 $0.00222
Haiku 4.5 $0.00011 $0.00111

Measured 8d ago against content hash c0ba146956a4, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

htmlhint 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.

Origin

Copies of this mod

2 near-identical copies found in the catalogue:

catalog/Tools/HTMLHint/skills/htmlhint/SKILL.md · 99 lines

How it starts

The opening of the file, as written. The whole thing — 99 lines — stays where its author put it; the contents beside it link to each section on GitHub.

HTMLHint for Static HTML in .NET Repositories

Trigger On

  • the repo has static HTML files, generated frontend output, or standalone templates under wwwroot/, dist/, or other web folders
  • the user asks for HTML structure checks, invalid attribute detection, or basic DOM-quality linting
  • the repo wants a narrow HTML gate separate from JS, CSS, and full-site runtime audits

Do Not Use For

  • raw .cshtml or .razor source with server-side directives; lint the rendered or published output instead
  • JavaScript or TypeScript linting; route that to eslint
  • runtime performance, accessibility, SEO, or headers; route that to webhint

Inputs

  • the nearest AGENTS.md
  • package.json
  • .htmlhintrc or equivalent config if present
  • the real static HTML target: source templates, built output, or deployed URL

Workflow

  1. Choose the right target first:
    • static HTML source files
    • generated build output such as dist/
    • a reachable URL when the page is already served
  2. Prefer repo-local installation and checked-in config for repeatable runs.
  3. Keep HTMLHint focused on static HTML correctness and lightweight policy.
  4. Add narrow scripts to package.json, for example:
    • htmlhint "dist/**/*.html"
    • htmlhint "wwwroot/**/*.html"
  5. If the repo has templating syntax that confuses the parser, lint the rendered output instead of forcing source templates through the tool.
  6. Use rule overrides deliberately for real project conventions; do not disable broad classes of checks just to make a noisy first pass green.
  7. Rerun the publish or frontend build flow if fixes touched generated or packaged HTML sources.

Bootstrap When Missing

  1. Detect current state:
    • rg --files -g 'package.json' -g '.htmlhintrc*' -g '*.html'
    • rg -n '"htmlhint"' --glob 'package.json' .
  2. Prefer a repo-local install:
    • npm install --save-dev htmlhint
  3. Add or refine .htmlhintrc only after confirming the actual target files.
  4. Add repeatable commands to AGENTS.md and package.json, then verify with:
    • npx htmlhint "dist/**/*.html"
    • npx htmlhint https://example.com
  5. Return status: configured if HTMLHint now owns a clear static-HTML gate, or status: improved if the existing setup was tightened.
  6. Return status: not_applicable when the repo's HTML is primarily server-rendered templates that should be validated after rendering instead.

Read the full file on GitHub · 99 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. 8d ago First seen · 99 lines · 105 tokens per session scan A c0ba146956a4

Subscribe to this mod's changes

htmlhint is a skill published in the GitHub repository managedcode/dotnet-skills (478 stars, last pushed 6d ago), licensed MIT. It adds 105 tokens to every session and 1,109 once invoked, about $0.0005 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 2026-09-03.

Related

Other skills, from other repositories

winui-design

Use when designing, reviewing, or fixing WinUI 3: sample and control discovery with winapp find-ui, layout planning, control choice, Fluent Design alignment, Light/Dark/High Contrast theming, typography, spacing, brushes, accessibility, and XAML data-binding design. Load before authoring new XAML, reviewing UI PRs…

microsoft/win-dev-skills · 119 tokens

winui-wpf-migration

Migrate WPF applications to WinUI 3 — namespace replacement (System.Windows → Microsoft.UI.Xaml), control mapping (DataGrid→ListView, WrapPanel→ItemsRepeater, TabControl→TabView), threading (Dispatcher→DispatcherQueue), imaging (System.Drawing→BitmapImage), MVVM conversion to CommunityToolkit.Mvvm, and…

microsoft/win-dev-skills · 100 tokens

aksel-builder

Expert builder for Aksel, the Nav / @navikt design system — React components, design tokens, layout primitives, theming (light/dark), icons, CSS, the Tailwind preset, version migrations, Figma-to-code. Triggers — Aksel, "using/with aksel", Nav/Navikt, "designsystemet", "design system", @navikt/ds- (e.g.…

navikt/copilot · 181 tokens

nav-dekoratoren

Integrer og konfigurer Nav Dekoratøren – felles header og footer for nav.no-applikasjoner. Bruk når et team skal ta i bruk Dekoratøren, oppdatere konfigurasjon, legge til breadcrumbs/språkvelger/analytics, håndtere samtykke (ekomloven), CSP eller feilsøke integrasjon mot dekoratøren.

navikt/copilot · 86 tokens

aksel-spacing

Lag responsive layouts med Aksel Design System (v8+) - spacing tokens, layout primitives (Box, HStack, VStack, HGrid, Page, Bleed) og ResponsiveProp.

navikt/copilot · 41 tokens

web-design-reviewer

Visuell inspeksjon av nettsider for å identifisere og fikse designproblemer. Trigges av forespørsler som "sjekk designet", "gå gjennom UI-en", "fiks layouten", "finn designfeil". Finner problemer med responsivt design, tilgjengelighet, visuell konsistens og layout, og fikser dem i kildekoden.

navikt/copilot · 89 tokens