SEO Technical: robots.txt#

Guides configuration and auditing of robots.txt for search engine and AI crawler control.

When invoking: On first use, if helpful, open with 1–2 sentences on what this skill covers and why it matters, then provide the main output. On subsequent use or when the user asks to skip, go directly to the main output.

Scope (Technical SEO)#

• Robots.txt: Configure Disallow/Allow, Sitemap, Clean-param; audit for accidental blocks
• Crawler access: Path-level crawl control; AI crawler allow/block strategy
• Differentiation: robots.txt = crawl control (who accesses what paths); noindex = index control (what gets indexed). See indexing for page-level exclusions.

Initial Assessment#

Check for project context first: If .claude/project-context.md or .cursor/project-context.md exists, read it for site URL and indexing goals.

Identify:

1. Site URL: Base domain (e.g., https://example.com)
2. Indexing scope: Full site, partial, or specific paths to exclude
3. AI crawler strategy: Allow search/indexing vs. block training data crawlers

Best Practices#

Purpose and Limitations#

PointNotePurposeControls crawler access; does NOT prevent indexing (disallowed URLs may still appear in search without snippet)AdvisoryRules are advisory; malicious crawlers may ignorePublicrobots.txt is publicly readable; use noindex or auth for sensitive content. See indexing

Crawl vs Index vs Link Equity (Quick Reference)#

ToolControlsPrevents indexing?robots.txtCrawl (path-level)No—blocked URLs may still appear in SERPnoindex (meta / X-Robots-Tag)Index (page-level)Yes. See indexing****nofollowLink equity onlyNo—does not control indexing

When to Use robots.txt vs noindex#

UseToolExamplePath-level (whole directory)robots.txtDisallow: /admin/, Disallow: /api/, Disallow: /staging/Page-level (specific pages)noindex meta / X-Robots-TagLogin, signup, thank-you, 404, legal. See indexing for full listCriticalDo NOT block in robots.txtPages that use noindex—crawlers must access the page to read the directive

Paths to block in robots.txt: /admin/, /api/, /staging/, temp files. Paths to use noindex (allow crawl): /login/, /signup/, /thank-you/, etc.—see indexing.

Location and Format#

ItemRequirementPathSite root: https://example.com/robots.txtEncodingUTF-8 plain textStandardRFC 9309 (Robots Exclusion Protocol)

Core Directives#

DirectivePurposeExampleUser-agent:Target crawlerUser-agent: Googlebot, User-agent: *``Disallow:Block path prefixDisallow: /admin/``Allow:Allow path (can override Disallow)Allow: /public/``Sitemap:Declare sitemap absolute URLSitemap: https://example.com/sitemap.xml``Clean-param:Strip query params (Yandex)See below

Critical: Do Not Block#

Do not blockReasonCSS, JS, imagesGoogle needs them to render pages; blocking breaks indexing/_next/ (Next.js)Breaks CSS/JS loading; static assets in GSC "Crawled - not indexed" is expected. See indexingPages that use noindexCrawlers must access the page to read the noindex directive; blocking in robots.txt prevents that

Only block: paths that don't need crawling: /admin/, /api/, /staging/, temp files.

AI Crawler Strategy#

robots.txt is effective for all measured AI crawlers ( Vercel/MERJ study, 2024). Set rules per user-agent; check each vendor's docs for current tokens.

User-agentPurposeTypicalOAI-SearchBotChatGPT searchAllowGPTBotOpenAI trainingDisallowClaude-SearchBotClaude searchAllowClaudeBotAnthropic trainingDisallowPerplexityBotPerplexity searchAllowGoogle-ExtendedGemini trainingDisallowCCBotCommon Crawl (LLM training)DisallowBytespiderByteDanceDisallowMeta-ExternalAgentMetaDisallowAppleBotApple (Siri, Spotlight); renders JSAllow for indexing

Allow vs Disallow: Allow search/indexing bots (OAI-SearchBot, Claude-SearchBot, PerplexityBot); Disallow training-only bots (GPTBot, ClaudeBot, CCBot) if you don't want content used for model training. See site-crawlability for AI crawler optimization (SSR, URL management).

Clean-param (Yandex)#

text

Clean-param: utm_source&utm_medium&utm_campaign&utm_term&utm_content&ref&fbclid&gclid

Output Format#

• Current state (if auditing)
• Recommended robots.txt (full file)
• Compliance checklist
• References: Google robots.txt

Related Skills#

• indexing: Full noindex page-type list; when to use noindex vs robots.txt; GSC indexing diagnosis
• page-metadata: Meta robots (noindex, nofollow) implementation
• xml-sitemap: Sitemap URL to reference in robots.txt
• site-crawlability: Broader crawl and structure guidance; AI crawler optimization
• rendering-strategies: SSR, SSG, CSR; content in initial HTML for crawlers