Agent Experience Optimization
(AX/AEO) — The Complete Guide
Your website has two audiences now. One of them is an AI agent. This guide covers everything you need to make your site discoverable, parsable, and actionable by ChatGPT, Claude, Perplexity, and autonomous agents.
What is Agent Experience Optimization?
Agent Experience Optimization (AEO) — also called AX (Agent Experience) — is the practice of making websites and applications discoverable, parsable, and actionable by AI agents.
Just as SEO made websites findable by search engines in the 2000s, AEO makes them usable by AI agents in the 2020s. The difference: search engines crawl and index. Agents crawl, understand, and act. They book appointments, start trials, compare pricing, and complete purchases — all without a human clicking anything.
The term was popularized by Mathias Biilmann (CEO, Netlify) who identified four pillars of AX: Access, Context, Tools, and Orchestration. We build on that framework with a quantitative scoring model across 6 measurable dimensions.
AEO vs SEO — How They Differ
| Aspect | SEO | AEO |
|---|---|---|
| Audience | Humans browsing search results | AI agents acting autonomously |
| Goal | Rank high, get clicks | Be cited, be actionable |
| Discovery | robots.txt, sitemap.xml | llms.txt, AGENTS.md, agent.json, MCP cards |
| Content format | HTML optimized for rendering | Markdown, SSR HTML, .md routes |
| Success metric | Rankings, traffic, CTR | Citations, API calls, task completion |
| Interaction | Click links, read pages | Call APIs, parse content, complete goals |
You need both. Strong SEO fuels AEO — AI systems prioritize content from domains with strong organic rankings and authority. But AEO adds an entirely new layer of optimization that SEO alone doesn't address.
The 6 Dimensions of Agent-Readiness
Every AX Audit scores your site across these 6 dimensions, each weighted by impact on real agent behavior.
Discoverability
20%Can agents find you? Checks robots.txt AI permissions, llms.txt, sitemap.xml, AGENTS.md, agent.json, MCP server cards, and OpenAPI specs.
Parsability
20%Can agents read your content? Tests server-side rendering vs client-only JS, .md Markdown routes, Accept: text/markdown content negotiation, and HTML cleanliness.
Semantic Structure
15%Do agents understand your content? Evaluates JSON-LD structured data coverage, heading hierarchy, Schema.org types, and anti-pattern detection.
API Surface
15%Can agents interact with your product? Checks for OpenAPI specs, ai-plugin.json manifests, MCP server discovery, and A2A Agent Cards.
Token Efficiency
10%Are you wasting agent tokens? Measures boilerplate ratio, page token counts, availability of llms-full.txt, and Markdown route support.
Agent Task Completion
20%Can agents actually do things on your site? Tests whether an LLM can find pricing, start a trial, or complete a purchase autonomously.
Key Standards to Implement
These are the files and protocols that agents look for when evaluating your site.
llms.txt
/llms.txtEstablishedMarkdown file at your site root providing a curated summary for LLMs. Adopted by Stripe, Cloudflare, Anthropic, Vercel.
AGENTS.md
/AGENTS.mdLinux FoundationOpen format for guiding coding agents. Contains build commands, conventions, and boundaries. Donated to AAIF by OpenAI and Anthropic.
agent.json
/.well-known/agent.jsonEmergingAgent-to-website communication protocol. Defines actions agents can take, with JSON Schema parameters and an inbox endpoint.
MCP Server Card
/.well-known/mcp/server-card.jsonMCP v2.1Standardized MCP server discovery. Advertises tools, transport, and auth requirements before connection.
agent-manifest.txt
/agent-manifest.txtIETF DraftCapability declaration for AI agents. Tells agents what they CAN do (vs robots.txt which says what they cannot).
The 4 Pillars of AX (Biilmann Framework)
Mathias Biilmann (Netlify CEO) defined four pillars for designing products that work with AI agents as primary users.
Access
Can agents access your product? Do they have permissions? Must a human be in the loop?
Context
Does the LLM know about your product? Do your responses build the right context for follow-up actions?
Tools
Are you building for agents? Do you offer MCP servers, APIs, and SDKs that reduce friction?
Orchestration
Can agents trigger workflows from your product? Do you offer sandboxes and environments for autonomous operation?
How to Measure Your AX Score
The fastest way to measure is our free AX Audit. Enter your URL and get scored across all 6 dimensions with specific, actionable remediation recommendations.
Frequently Asked Questions
Isn't this just SEO?▼
Do I need llms.txt if I have good SEO?▼
What's the difference between AGENTS.md and agents.txt?▼
Is JSON-LD structured data important for agents?▼
How often should I re-audit?▼
Can AINative fix my AX score for me?▼
Ready to optimize for agents?
Start with a free audit. See exactly how agents experience your site today, and get a prioritized roadmap to fix it.