portable-html

name	portable-html
description	Use this when a user asks to format, sanitize, inspect, outline, audit links, extract clean text, select nodes with CSS selectors, or convert local HTML to Markdown using moonrun and the bundled portable htmlfmt WASM artifact from this skill.

Portable HTML

Use this skill to format, inspect, and convert WASI-visible HTML files without a native HTML toolchain. It is best for agent workflows that need quick page triage, metadata extraction, CSS selector extraction, link review, basic accessibility hints, clean text, Markdown, or normalized HTML before further processing.

Quick Start

Inspect a full HTML document:

moonrun /path/to/portable-html/assets/htmlfmt.wasm \
  --inspect --document --file page.html

Format a fragment:

moonrun /path/to/portable-html/assets/htmlfmt.wasm \
  --file fragment.html \
  --output formatted.html

Extract readable text:

moonrun /path/to/portable-html/assets/htmlfmt.wasm \
  --text --file page.html

Convert HTML to Markdown:

moonrun /path/to/portable-html/assets/htmlfmt.wasm \
  --markdown --file page.html

Extract selected links as JSON:

moonrun /path/to/portable-html/assets/htmlfmt.wasm \
  --select 'main a[href]' --json --document --file page.html

Sanitize and compact untrusted HTML:

moonrun /path/to/portable-html/assets/htmlfmt.wasm \
  --sanitize --compact --file input.html

Workflow

1. Use --inspect --document --file PAGE before summarizing or trusting an HTML document.
2. Check the report for metadata, outline, links, missing image alt text, scripts, and forms.
3. Use --json with --inspect when another tool should consume the report.
4. Use --text for concise summaries, search snippets, or prompt context.
5. Use --markdown when preserving headings, lists, links, and emphasis matters.
6. Use --select CSS to pull focused pieces out of larger pages before rendering as HTML, text, Markdown, or JSON.
7. Use --sanitize before formatting untrusted fragments.
8. Use --limit N to keep inspection or selector output concise.

Useful Options

• --inspect: write a Markdown inspection report instead of formatted HTML.
• --json: with --inspect, write compact JSON.
• --text: write clean block-oriented text.
• --markdown: convert the parsed HTML to Markdown.
• --html-passthrough: with --markdown, preserve unsupported source HTML.
• --select CSS: extract matching nodes before rendering.
• --document: parse as a full document instead of a fragment.
• --sanitize: apply the default sanitizer before formatting or inspection.
• --compact: write compact normalized HTML.
• --indent N: choose pretty-print indentation.
• --limit N: cap report rows.
• --file PATH: read a guest-visible file.
• --output PATH: write output to a guest-visible file.

Caveats

This is a lightweight structural inspection skill. It does not execute JavaScript, fetch linked resources, compute rendered accessibility trees, or validate every HTML/a11y rule.