# robots.txt — https://yangopen.com
# Search engines and AI/LLM crawlers are welcome to read, index and cite this site.

User-agent: *
Allow: /

# --- AI / LLM crawlers (training, search and retrieval) — explicitly allowed ---
User-agent: GPTBot
User-agent: OAI-SearchBot
User-agent: ChatGPT-User
User-agent: ClaudeBot
User-agent: Claude-Web
User-agent: Claude-SearchBot
User-agent: anthropic-ai
User-agent: PerplexityBot
User-agent: Perplexity-User
User-agent: Google-Extended
User-agent: Applebot-Extended
User-agent: Amazonbot
User-agent: Bytespider
User-agent: CCBot
User-agent: cohere-ai
User-agent: meta-externalagent
User-agent: Meta-ExternalAgent
User-agent: DuckAssistBot
User-agent: YouBot
Allow: /

# Machine-readable content guide for LLMs: https://yangopen.com/llms.txt
Sitemap: https://yangopen.com/sitemap.xml