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GoldziherGoldziher/html-to-markdown/skills/html-to-markdown-extracting-metadata/SKILL.md

html-to-markdown-extracting-metadata

Skill888 starsChanged 3 months agoMITView on GitHub

Use when extracting metadata from HTML — title, description, language, Open Graph, JSON-LD / Microdata / RDFa, headers, links, and images. Covers the --json output shape and the --extract-metadata flag.

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    This author's own choices. Worth a look.

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  1. Distinctive:

    Use this when the user wants structured metadata out of HTML rather than (or in addition to) the Markdown body — page title, description, …

    line 15

≈ “Common” is an estimate: at least 1 in 5 of the 308,232 skill files we read have a rule of the same kind, not the same words. “Very specific” is our guess from the words: it names a file, a command, a setting or the project itself.

Keep what fits and drop the rest. Your version, ready for your agents.
Files
SKILL.md
<!-- AI-RULEZ :: GENERATED FILE — DO NOT EDIT Content-Hash: blake3:008ee34eae3d73ceed0d8a9c7fdb8ae8562558ccef3be60bac93f03dbf362e29 Source-Hash: blake3:25aff2d6495f85f31e43d878c418221ab6d2edce946baaa4716510a2c8633f5b Schema-Version: v1 -->

Extracting metadata

Use this when the user wants structured metadata out of HTML rather than (or in addition to) the Markdown body — page title, description, language, Open Graph tags, structured data, the heading outline, links, or image references.

Metadata lives in result.metadata and is surfaced on the CLI through --json. On the CLI, metadata extraction is opt-in: pass --extract-metadata alongside --json, otherwise result.metadata comes back empty (document.title is null, headers/links/images/structured_data are []). The library convert() call extracts metadata by default (extract_metadata=True) — that default is a property of the API, not the CLI. There are no per-field extraction flags: --extract-metadata populates all sub-fields below at once.

Get all metadata

html-to-markdown --json --extract-metadata input.html | jq '.metadata'

# Extraction-only (skip the Markdown body)
html-to-markdown --json --extract-metadata --no-content input.html | jq '.metadata'

Metadata sub-fields

{
  "metadata": {
    "document": { "title": "...", "description": "...", "language": "en", "open_graph": {"title": "..."} },
    "headers": [ { "level": 1, "text": "Main Heading" } ],
    "links":   [ { "href": "https://example.com", "link_type": "external" } ],
    "images":  [ { "src": "photo.jpg", "alt": "A photo", "image_type": "external" } ],
    "structured_data": [ /* JSON-LD, Microdata, RDFa blocks */ ]
  }
}

Metadata flag

There is one metadata flag: --extract-metadata. With --json set it populates all sub-fields above (document, headers, links, images, structured_data) under result.metadata — select what you need with jq.

FlagEffect
--extract-metadataWith --json: populate result.metadata. In plain-text mode (no --json): prepend title + meta tags as a YAML frontmatter block (----delimited) at the top of the Markdown output
# Pull just the document-level metadata and the heading outline
html-to-markdown --json --extract-metadata --no-content input.html \
  | jq '{title: .metadata.document.title, lang: .metadata.document.language, outline: [.metadata.headers[].text]}'

Common queries

# Title + canonical language
html-to-markdown --json --extract-metadata input.html | jq '{title: .metadata.document.title, lang: .metadata.document.language}'

# External links only
html-to-markdown --json --extract-metadata input.html | jq '[.metadata.links[] | select(.link_type == "external") | .href]'

# Open Graph card
html-to-markdown --json --extract-metadata input.html | jq '.metadata.document.open_graph'

# JSON-LD blocks
html-to-markdown --json --extract-metadata input.html | jq '.metadata.structured_data'

Programmatic access

from html_to_markdown import convert

html = """
<html lang="en">
<head><title>My Article</title></head>
<body>
<h1>Main Heading</h1>
<a href="https://example.com">External link</a>
<img src="photo.jpg" alt="A photo">
</body>
</html>
"""
result = convert(html)
meta = result.metadata
print(meta.document.title)        # "My Article"
print(meta.document.language)     # "en"
print(meta.headers[0].text)       # "Main Heading"
print(meta.links[0].link_type)    # "external"
print(meta.images[0].alt)         # "A photo"

Metadata is available from the single convert() call in Python, Rust, Go, Ruby, and Elixir; in TypeScript read it off the returned result object. In Rust it requires the metadata feature (on by default).

See references/cli-reference.md (Metadata section) and references/configuration.md for field details.

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