Claude-seo-skills seo-llms-txt

install

source · Clone the upstream repo

git clone https://github.com/lionkiii/claude-seo-skills

Claude Code · Install into ~/.claude/skills/

T=$(mktemp -d) && git clone --depth=1 https://github.com/lionkiii/claude-seo-skills "$T" && mkdir -p ~/.claude/skills && cp -r "$T/skills/seo-llms-txt" ~/.claude/skills/lionkiii-claude-seo-skills-seo-llms-txt && rm -rf "$T"

manifest: skills/seo-llms-txt/SKILL.md

source content

llms.txt — Generate, Validate & Audit

Analyze, generate, or validate llms.txt files per the llms.txt specification (proposed by Jeremy Howard / Answer.AI). The llms.txt standard provides a Markdown file at

/llms.txt

that helps LLMs understand a website's content structure — similar to how robots.txt guides traditional crawlers.

Adoption: 950+ sites including Anthropic, Cloudflare, Docker, Vercel, Stripe, FastHTML, Cursor, Hugging Face, and many more.

Inputs

Three modes, auto-detected from the user's input:

Input Pattern	Mode	Example
`/seo llms-txt <url>`	Audit	`/seo llms-txt example.com`
`/seo llms-txt generate <url>`	Generate	`/seo llms-txt generate example.com`
`/seo llms-txt validate <url-or-path>`	Validate	`/seo llms-txt validate /path/to/llms.txt`

If user provides a URL without sub-command → Audit mode (fetch and check existing file)
If user says "generate" → Generate mode (crawl site, produce llms.txt)
If user says "validate" → Validate mode (parse and check against spec)

llms.txt Spec Reference

@skills/seo/references/llms-txt-spec.md

Quick Spec Summary

The llms.txt file must be valid Markdown with this structure:

H1 heading (required) — Project/site name
Blockquote (optional) — Short site summary
H2 sections — Categorized link lists with descriptions
Link format:
```
- [Name](url): Description
```
(colon + space after URL)
## Optional
section — Links useful but not essential for understanding
Companion files (optional):
- ```
llms-full.txt
```
  — Comprehensive version with full content
- Individual
```
.md
```
  page mirrors for key pages

Execution: Audit Mode

When user provides a URL (no sub-command):

Fetch llms.txt: Use WebFetch to retrieve
```
<url>/llms.txt
```
Run 8-point check:

#	Check	Pass Criteria
1	File exists	HTTP 200 at `/llms.txt`
2	Valid Markdown	Parseable as Markdown, no broken syntax
3	Has H1	Exactly one `#` heading
4	Has blockquote summary	`>` line present after H1 (recommended)
5	Has H2 sections	At least one `##` section with links
6	Link format correct	Links follow `- [Name](url): description` pattern
7	Has `## Optional`	Contains an Optional section (recommended)
8	Companion llms-full.txt	`llms-full.txt` exists at same path (recommended)

Link spot-check: WebFetch up to 5 linked URLs to verify they resolve (HTTP 200)
Generate score card and recommendations

Execution: Generate Mode

When user says "generate":

Crawl site structure:
- WebFetch the homepage — extract title, meta description, nav links
- WebFetch
```
/sitemap.xml
```
  (or
```
/sitemap_index.xml
```
  ) — extract all URLs
- If no sitemap, follow nav links from homepage (up to 50 pages)

Categorize pages into sections based on URL patterns and content:

## Docs

—

/docs/

/documentation/

/guides/

/reference/

```
## Blog
```
—
```
/blog/
```
,
```
/articles/
```
,
```
/posts/
```
,
```
/news/
```
```
## API
```
—
```
/api/
```
,
```
/developers/
```
,
```
/reference/
```

## Products

—

/products/

/features/

/pricing/

/solutions/

```
## About
```
—
```
/about/
```
,
```
/team/
```
,
```
/company/
```
,
```
/contact/
```
```
## Legal
```
—
```
/privacy/
```
,
```
/terms/
```
,
```
/legal/
```
```
## Optional
```
— Catch-all for remaining useful pages

Extract metadata per page:
- Title (from
```
<title>
```
  or
```
<h1>
```
  )
- Description (from
```
meta[name=description]
```
  or first paragraph)
- Truncate description to ~100 characters

Generate llms.txt:

# Site Name

> Brief site description from meta or homepage hero text.

## Docs

- [Getting Started](https://example.com/docs/start): Introduction and setup guide
- [API Reference](https://example.com/docs/api): Complete API documentation

## Blog

- [Latest Post](https://example.com/blog/post): Description of the post

## Optional

- [About](https://example.com/about): Company background
- [Contact](https://example.com/contact): Get in touch

Generate llms-full.txt skeleton (optional — note to user):

Suggest that llms-full.txt should contain the full Markdown content
of all key pages concatenated. Provide the structure but note that
generating full content requires crawling every page.

Output the generated file — display it in a code block and offer to write to disk

Execution: Validate Mode

When user says "validate":

Load the file:
- If URL → WebFetch
```
<url>/llms.txt
```
- If local path → Read the file
Run spec compliance checks:

#	Rule	Severity	Check
1	Has exactly one H1	FAIL	Count `#` lines (not `##` )
2	H1 is first heading	FAIL	First line starting with `#` must be H1
3	Valid Markdown	FAIL	No broken link syntax, unclosed brackets
4	Links use correct format	WARN	`- [Name](url): description` pattern
5	Has at least one H2 section	FAIL	At least one `##` heading
6	No empty sections	WARN	Every H2 should have at least one link
7	Blockquote present	INFO	`>` after H1 is recommended
8	`## Optional` section exists	INFO	Recommended by spec
9	No deep heading levels	WARN	Only H1 and H2 allowed (no H3+)
10	Descriptions present	WARN	Links should have `: description` after URL

Output pass/fail per rule with line numbers for failures

Output Format

Audit Mode Output

## llms.txt Audit: [domain]

**Score: X/8 checks passed**

| # | Check | Result | Details |
|---|---|---|---|
| 1 | File exists | PASS/FAIL | [status code or error] |
| 2 | Valid Markdown | PASS/FAIL | [issue if any] |
| ... | ... | ... | ... |

### Link Spot-Check
| URL | Status |
|---|---|
| [url] | 200 OK / 404 / timeout |

### Recommendations
- [Prioritized list of improvements]

### What is llms.txt?
> llms.txt is a proposed standard (llmstxt.org) that provides LLMs with
> a structured Markdown overview of your site. 950+ sites have adopted it.
> While AI platform adoption of the standard is still emerging, early
> adoption positions your site for AI search visibility — similar to how
> early schema.org adoption paid off for rich snippets.

Generate Mode Output

## Generated llms.txt for [domain]

[The generated llms.txt content in a code block]

### Generation Notes
- Pages crawled: [count]
- Sections created: [list]
- Pages excluded: [count and reason]

### Next Steps
1. Review and edit the generated file
2. Upload to your site root as `/llms.txt`
3. Consider creating `llms-full.txt` with full page content
4. Add `<link rel="help" href="/llms.txt">` to your HTML head (optional)

Validate Mode Output

## llms.txt Validation: [source]

**Result: X/10 rules passed** | Y warnings | Z info

| # | Rule | Result | Line | Details |
|---|---|---|---|---|
| 1 | Has H1 | PASS/FAIL | [line#] | [details] |
| ... | ... | ... | ... | ... |

### Issues to Fix
- [FAIL items with specific fix instructions]

### Recommendations
- [WARN items with suggestions]