robots-txt-audit

robots-txt-audit is a skill for Claude Code, Codex from JakeLabate/Claude-SEO-Skills. It costs 160 tokens per session (1,791 once invoked), scanned A, original, MIT.

A website audit tool for robots.txt, the text file that tells search-engine crawlers which pages and resources they may fetch.

In plain words
What is it for?
Use it to check robots.txt, test whether important CSS, JavaScript, and images are accessible to crawlers, and verify that the sitemap is declared and served as plain text.
Why use it?
It finds setup problems that can stop search engines from crawling a site correctly, including redirects, server errors, broad blocks, syntax errors, and blocked page resources. Crawling is fetching pages; it is different from indexing them in search results.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to check robots.txt, test whether important CSS, JavaScript, and images are accessible to crawlers, and verify that the sitemap is declared and served as plain text.

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Install with agentmods
npx agentmods add skills/jakelabate/claude-seo-skills/robots-txt-audit
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 JakeLabate/Claude-SEO-Skills --skill robots-txt-audit
Clone the repo
git clone --depth 1 https://github.com/JakeLabate/Claude-SEO-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 robots-txt-audit

README.md
[![agentmods](https://agentmods.dev/badge/skills/jakelabate/claude-seo-skills/robots-txt-audit/github.svg)](https://agentmods.dev/skills/jakelabate/claude-seo-skills/robots-txt-audit)
Your own site
<a href="https://agentmods.dev/skills/jakelabate/claude-seo-skills/robots-txt-audit"><img src="https://agentmods.dev/badge/skills/jakelabate/claude-seo-skills/robots-txt-audit/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 robots-txt-audit

Your own site · 80×15
<a href="https://agentmods.dev/skills/jakelabate/claude-seo-skills/robots-txt-audit"><img src="https://agentmods.dev/badge/skills/jakelabate/claude-seo-skills/robots-txt-audit.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 160 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,791 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.
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 $0.00160 $0.01791
Opus 5 $0.00080 $0.00896
Sonnet 5 $0.00032 $0.00358
Haiku 4.5 $0.00016 $0.00179

Measured 12d ago against content hash 8c7ef725abaf, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

robots-txt-audit 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 12d ago.

The scan reads SKILL.md. This mod also ships 4 executable files (scripts/audit_robots.py, scripts/collect_robots.py, scripts/findings_to_csv.py, …), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

skills/robots-txt-audit/SKILL.md · 129 lines

How it starts

The opening of the file, as written. The whole thing — 129 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Robots.txt Audit

Audit a website's robots.txt file and produce an actionable SEO report.

When to use this skill

Use this skill when the user asks to:

  • Audit, validate, or check a robots.txt file or crawl directives
  • Find out why pages are not being crawled or why Google says a URL is "blocked by robots.txt"
  • Check that important pages aren't blocked and that CSS/JS resources can be rendered
  • Confirm robots.txt declares the XML sitemap and returns 200 as plain text
  • Catch a stray Disallow: / that took the whole site out of search
  • Clean up syntax errors and unsupported directives (noindex, crawl-delay, etc.)

Inputs to collect

Before starting, confirm with the user:

  1. Site URL or robots.txt URL — a live site root (e.g., https://example.com, which fetches /robots.txt) or a specific robots.txt URL (--robots).
  2. Resource check — whether to fetch the homepage and test its CSS/JS/image references against the rules (default on). Use --no-resources to skip it.

What robots.txt does and does not do: robots.txt controls crawling, not indexing. A Disallow stops compliant crawlers from fetching a page, but a blocked URL can still be indexed (without a snippet) if other pages link to it. To keep a page out of the index, allow crawling and use a noindex meta tag or X-Robots-Tag header instead — noindex inside robots.txt is unsupported and ignored. Most checks here protect crawl access and rendering rather than indexing.

Workflow

Step 1: Fetch and parse robots.txt

Use scripts/collect_robots.py:

python3 scripts/collect_robots.py https://example.com --output robots_inventory.json

Point directly at a robots.txt with --robots:

python3 scripts/collect_robots.py https://example.com/robots.txt --robots --output robots_inventory.json

The script fetches /robots.txt without auto-following redirects (so a redirected or HTML-served file is visible), records HTTP status, content type, byte size, gzip, and a BOM flag, then parses user-agent groups, Sitemap: directives, comments, unknown/unsupported directives, and per-line syntax errors. It probes every declared sitemap URL for status and (unless --no-resources) fetches the homepage to test same-host CSS/JS/image references against the * group's rules.

Read the full file on GitHub · 129 lines

Files

What ships with it

6 files 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. 12d ago First seen · 129 lines · 0 tokens per session scan A 8c7ef725abaf

Subscribe to this mod's changes

robots-txt-audit is a skill published in the GitHub repository JakeLabate/Claude-SEO-Skills (2 stars, last pushed 2mo ago), licensed MIT. It adds 160 tokens to every session and 1,791 once invoked, about $0.0008 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 2026-08-31.