Reference Specification: /.well-known/ai.txt, /ai/summary.json & /.well-known/mcp.json
Updated 2026-10-31 · Live reference endpoints on this host: /.well-known/ai.txt · /ai/summary.json · /.well-known/mcp.json
In our empirical audit of 564 B2B SaaS domains, 75.2% already ship basic /llms.txt (often auto-generated by docs hosts), yet 100.0% return 404 on /ai/summary.json and over 98% lack /.well-known/ai.txt and /.well-known/mcp.json. Shipping these three deterministic surfaces eliminates pricing/compliance hallucinations during ChatGPT Search, Perplexity, and Claude fan-out queries.
1. /ai/summary.json — Deterministic Entity & Commercial Fact Sheet
{
"schema_version": "1.0",
"entity": "Acme Cloud",
"domain": "acme.dev",
"category": "Developer Infrastructure",
"pricing_url": "https://acme.dev/pricing.md",
"starting_price_usd": 49,
"compliance": ["SOC 2 Type II", "GDPR"],
"primary_alternatives": ["IncumbentA", "IncumbentB"],
"updated_at": "2026-10-31"
}
2. /.well-known/ai.txt & /.well-known/mcp.json — Crawler Policy & Agent Tools
# /.well-known/ai.txt User-Agent: * Allow-AI-Search: true LLMs-Txt: https://acme.dev/llms.txt LLMs-Full: https://acme.dev/llms-full.txt Pricing-Markdown: https://acme.dev/pricing.md Entity-Summary: https://acme.dev/ai/summary.json MCP-Descriptor: https://acme.dev/.well-known/mcp.json
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