The llm-index.json File
Property-by-property reference for the core LLM-LD file. Every field, what it does, when to use it, and complete examples.
The llm-index.json file is the heart of Layer 3. It's a single file that gives AI systems and agents everything they need to understand your business — without crawling your entire site.
Your website is for humans. Your llm-index.json is a website for AI.
This file lives at /.well-known/llm-index.json — a standard location that AI systems can check automatically, just like robots.txt or security.txt.
Prerequisite: Layer 3 requires Layers 1 and 2. Before creating your llm-index.json, make sure you have Schema.org markup (Layer 1) and entities/knowledge graph (Layer 2) in place.
On this page
File structure
Here's the basic structure of an llm-index.json file:
Let's go through each property in detail.
@context
Declares the vocabularies used in this file. Always include both Schema.org and LLM-LD namespaces.
Identifies this as an LLM-LD index file. Always set to llmld:Index.
llmld:summary
The summary section gives AI a quick understanding of your business. This is often the first thing AI reads, so make it count.
Your business in one sentence. This should be clear, specific, and differentiated. Avoid jargon. Think: how would you describe your business to a stranger in 10 seconds?
3-5 differentiators that make you stand out. What would make someone choose you over competitors? Include concrete details — years in business, certifications, unique offerings.
List of your primary services or products. Be specific — these help AI match you to user queries.
Geographic area you serve. Critical for local businesses. Can be a city, region, or list of areas.
llmld:actions
This is where you tell AI what you want it to recommend. When someone asks for a dentist, should AI suggest they book an appointment? Call you? Visit your website? Be explicit.
Your main call-to-action. What's the #1 thing you want users to do? This is what AI will recommend first.
Alternative actions. Maybe they want to call instead of book online, or learn more before committing.
Action types: schedule, purchase, contact, signup, download, learn, reserve, quote. Pick the type that best describes what happens when someone clicks.
llmld:contact
Complete contact information. This should match what's in your Schema.org markup — consistency matters.
Primary contact email address.
Primary phone number. Use international format with country code.
Physical address. Include all components for best results.
llmld:hours
Business hours in a simple, readable format. This helps AI answer "Are they open now?" questions.
Hours for each day of the week. Use "Closed" for days you're not open.
llmld:pointers
Links to your Layer 2 files. This tells AI where to find deeper information about your entities and relationships.
URL to your entities.json file.
URL to your knowledge-graph.json file.
Real-time data feeds (inventory, availability, pricing, etc.).
Complete examples
Here are full llm-index.json files for different business types. Use these as starting templates.
Validation: After creating your file, use the LLM-LD Validator to check for errors and ensure your file is properly formatted.
Ready to create your llm-index.json?
Follow the Quick Start guide for a complete implementation walkthrough.