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llms-txt

Use when creating /llms.txt and /llms-full.txt endpoints for LLM crawler discoverability. Also use when a site needs to be findable and citable by AI assistants, or when implementing the llmstxt.org specification.

ModelSource
sonnetpack: ai-visibility
  • Creating /llms.txt or /llms-full.txt endpoints for a site
  • A site needs to be findable and citable by LLM crawlers (ChatGPT, Claude, Gemini, Perplexity)
  • Implementing the llmstxt.org specification
  • An existing site’s AI discoverability is unknown or zero
  • Complementing SEO with AI search presence

AI discoverability is the new SEO. By 2026, a quarter of organic search traffic routes through AI assistants — ChatGPT, Claude, Gemini, Perplexity. Sites not discoverable to LLM crawlers get hallucinated over or ignored entirely.

llms.txt is a markdown file at /llms.txt that gives AI systems a canonical, curated summary of what a site is and what it does. Analogous to robots.txt — but instead of controlling access, it controls understanding.

Why it matters: LLMs frequently hallucinat

Full Reference

Mandatory Announcement — FIRST OUTPUT before anything else:

┏━ 🛡 llms-txt ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┓ ┃ Generating LLM discovery endpoints for [site] ┃ ┗━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┛

ItemValue
File location/llms.txt at site root
Content-Typetext/plain; charset=utf-8
Cache-Controlpublic, max-age=86400
FormatPlain markdown only — no HTML, no frontmatter
Required sectionsH1, blockquote, About, Services, Contact, Learn More, Citation Guidelines
Optional sectionsRecent Articles
Data sourcebusiness.json — never hardcode NAP data
Extended version/llms-full.txt — full content, not just links
I want to…File
Understand the spec and required formatreference/spec-and-format.md
Implement for Astro (content collections)reference/astro-implementation.md
Implement for Next.js or SvelteKitreference/nextjs-implementation.md
Use a static file or verify the endpointreference/static-and-verification.md

Usage: Read the reference file matching your current task from the index above. Each file is self-contained with code examples and inline gotchas.

  • Creating /llms.txt or /llms-full.txt endpoints for a site
  • A site needs to be findable and citable by LLM crawlers (ChatGPT, Claude, Gemini, Perplexity)
  • Implementing the llmstxt.org specification
  • An existing site’s AI discoverability is unknown or zero
  • Complementing SEO with AI search presence

AI discoverability is the new SEO. By 2026, a quarter of organic search traffic routes through AI assistants — ChatGPT, Claude, Gemini, Perplexity. Sites not discoverable to LLM crawlers get hallucinated over or ignored entirely.

llms.txt is a markdown file at /llms.txt that gives AI systems a canonical, curated summary of what a site is and what it does. Analogous to robots.txt — but instead of controlling access, it controls understanding.

Why it matters: LLMs frequently hallucinate business details (wrong phone, wrong hours, closed locations). llms.txt provides a ground-truth reference. When Claude or ChatGPT fetches it during a query, they get accurate data instead of guessing.

Read stack.json before generating any code. Check .claude/stack.json for the framework, then go to the matching reference file.

FrameworkReference File
Astroreference/astro-implementation.md
Next.jsreference/nextjs-implementation.md
SvelteKitreference/nextjs-implementation.md
Static / Nonereference/static-and-verification.md

When business.json does NOT exist at the project root, stop and prompt: “No business.json found — run nap-ninja first to centralize business data, or provide the business info manually.”

Never hardcode phone numbers, addresses, hours, or business names.

TaskSkill
Implement /llms.txt endpointllms-txt (this skill)
Check if site is cited by AIai-visibility
Optimize content for AI citationai-visibility
Create /ai-info pageai-info-page
Centralize business datanap-ninja