ASO Agent Signal Optimization

SEO for autonomous agents

Agent Signal Optimization (ASO)

SEO was built for search engines and human clicks. ASO is built for AI shoppers, browser agents, research assistants, and buying bots that decide which links, products, and sources can be found, cited, recommended, invoked, paid for, and remembered in search-backed chat responses.

The next visitor who matters may not be human. If an AI shopper, browser agent, research assistant, or buying bot lands on your site tonight, will it understand what you sell, trust the source, and know what to do next? ASO gives you the score, framework, and free self-assessment to find the gaps before agents skip you.

Take a free ASO self-assessment Compare agent readiness checks
agent-selection.trace ASO signal path
6

Signal pillars

100

ARI max score

9

Launch artifacts

3

Readable manifests

The new traffic alarm

People are not the only visitors deciding who gets found anymore.

Product pages, booking flows, storefronts, APIs, directories, and service businesses are about to be judged by software that does not browse like a person. Agents look for explicit signals: what you do, what can be trusted, what can be invoked, what costs money, and where the canonical answer lives. If those signals are missing, the agent may skip you before a human ever sees the page.

Definition

ASO is the service layer after SEO.

SEO ranks pages for people. AEO, GEO, and LLMO improve answer visibility. ASO prepares services for agent selection, invocation, payment, and repeat use.

The easiest way to understand ASO is to start with the job SEO did for the web. SEO made pages legible to search engines so humans could find them. ASO makes services legible to autonomous agents so agents can choose, call, pay for, recommend, and return to them.

That shift changes the optimization target. A page can win SEO by being relevant and authoritative. A service wins ASO by being machine-readable, callable, trustworthy, priced clearly, and stable enough for an agent to remember.

SEO Page discovery

Keywords, links, crawl health, content quality, and human click-through.

AEO / GEO / LLMO Answer visibility

Retrievable explanations, citations, source authority, and brand mentions.

ASO Agent usability

Manifests, callable specs, auth clarity, trust evidence, pricing, and durable memory.

SEO to ASO

The old search properties now have agent-facing equivalents.

ASO does not replace SEO. It extends the same basic idea into a world where the visitor may be an autonomous client instead of a human using a browser.

Some web properties carry over directly: `robots.txt` and `sitemap.xml` still matter. Others need agent-native companions. A blog post may help an answer engine cite you, but an agent needs a manifest, a callable contract, and explicit policy boundaries before it can safely use you.

SEO property What it did ASO property What changes
robots.txt

Crawler access rules.

robots.txt plus AI crawler policy

Separates indexing, retrieval, training, and agent access.

sitemap.xml

URL inventory for search engines.

sitemap.xml plus llms.txt

Pairs page inventory with a curated reading path for agents.

meta title and description

Human-facing result snippets.

agent.json and schema.org

Machine-readable identity, service type, owner, and capabilities.

structured data

Entity and content context.

OpenAPI, MCP, and manifests

Callable interface, parameters, auth, responses, and errors.

backlinks and citations

Authority signals.

registry listings and reputation signals

Evidence an agent can use to compare services and reduce risk.

conversion funnel

Forms, CTAs, demos, and sales pages.

agent-safe invocation and payment path

Documented auth, pricing, x402 or payment manifest, and constraints.

brand recall

Humans remember and search again.

persistent service memory

Agents return through stable IDs, versioned docs, and consistent endpoints.

Agent Flow

The old web waits for humans. The agentic web negotiates through signals.

A human can tolerate ambiguity. They can click around, infer intent, fill out a form, or ask sales what an API actually does. An agent has a narrower tolerance. If it cannot identify the service, verify the rules, and find a safe invocation path, it will usually choose another option.

ASO turns that fragile browsing process into a deterministic evaluation path. The agent finds public signals, resolves identity, checks trust and commerce constraints, invokes the service, then stores the service as a future candidate.

Without ASO

  1. Agent crawls a marketing page.
  2. JavaScript hides key service details.
  3. Pricing and auth are ambiguous.
  4. No callable contract is found.
  5. The service is skipped.

With ASO

  1. Agent reads robots.txt and llms.txt.
  2. Agent resolves identity through agent.json.
  3. Agent validates trust and policy boundaries.
  4. Agent invokes OpenAPI, MCP, or x402 routes.
  5. The service becomes a remembered option.

Signal Stack

The minimum viable agent surface.

A service becomes agent-readable when its public surface answers three questions without a sales call: what are you, how do I call you, and why should I trust you?

Discovery files are not the whole discipline, but they are where the agent starts. The first layer tells crawlers that a service exists. The next layers tell agents what the service does, how to call it, how risk is handled, and whether money can move without a human in the loop.

01

Discovery files

robots.txt, sitemap.xml, llms.txt, /.well-known/ai, and /.well-known/agents.json.

GET /llms.txt
02

Identity manifest

agent.json, schema.org, service type, version, owner, canonical URLs, and compatibility.

GET /agent.json
03

Invocation contract

OpenAPI, MCP, auth schemes, endpoint semantics, input constraints, errors, and examples.

GET /openapi.json
04

Trust evidence

HTTPS, status, provenance, rate limits, governance, uptime, and operational boundaries.

GET /.well-known/status
05

Commerce and memory

Pricing, payment manifests, x402 routes, registry state, versioned docs, and stable return paths.

GET /.well-known/payments

Framework

Six auditable signal categories.

The six pillars keep ASO from becoming a checklist of random files. Each pillar answers a decision an autonomous agent must make before it can use a service: can I find it, understand it, trust it, pay for it, compare it, and remember it?

01

Discoverability

Can agents find the service through crawl rules, maps, manifests, and directories?

02

Identity

Can agents understand the service name, owner, type, version, capabilities, and canonical endpoints?

03

Trust

Can agents verify domain, auth, governance, status, provenance, and operational safety?

04

Commerce

Can agents understand pricing, payment requirements, x402 endpoints, and purchase constraints?

05

Reputation

Can agents compare uptime, completion rates, citations, directory listings, and third-party evidence?

06

Memory

Can agents return through stable URLs, persistent identity, versioned docs, and consistent signals?

ASO Score

Agent Readiness Index

The Agent Readiness Index is a 0-100 score that grades how prepared a service is for autonomous agent discovery, evaluation, invocation, payment, recommendation, and reuse.

The score is intentionally concrete. A service should not receive credit for saying it is agent-ready. It receives credit for public signals an agent, auditor, or crawler can verify.

Read the scoring rubric
ASO-0Invisible0-9
ASO-1Discoverable10-29
ASO-2Understandable30-49
ASO-3Invocable50-69
ASO-4Trustable70-89
ASO-5Commerce-ready90-100

Readiness vs ASO

Agent readiness is technical compliance. ASO is agent selection.

Agent readiness scanners are a useful first pass. They check whether agents can find a site, read it, authenticate against it, discover protocols, and understand commerce surfaces. ASO turns the same signal hunt into a selection framework: identity, trust, commerce, reputation, memory, traffic, and conversion evidence.

01

Scanner result

Readiness checks answer: can agents inspect this site without guessing?

02

ASO score

The Agent Readiness Index answers: how exposed, credible, and commercially useful are the signals?

03

ASO framework

The six pillars answer: what should be fixed before agent traffic starts choosing winners?

04

ASO certification

Certification answers: what was verified, when, and whether the claim survives inspection?

Layer 1

Agent Readiness

Can agents technically inspect, read, authenticate, and discover the service?

Layer 2

Agent Signal Optimization

Will agents understand, trust, compare, choose, pay for, and remember the service?

Layer 3

Agent Performance

Are agents actually finding, citing, invoking, converting, and returning?

Signal Agent Readiness ASO
robots.txtYesYes
sitemap.xmlYesYes
llms.txt and Markdown accessYesYes
MCP, API, and auth discoveryYesYes
Trust and provenancePartialYes
Reputation and third-party evidenceNoYes
Commerce readiness and purchase rulesPartialYes
Memory and return pathsNoYes
Agent traffic, citations, and conversionsNoYes
Take a free ASO self-assessment

What agents inspect

The new agent surface is not one file. It is a signal stack.

ASO treats every public artifact as evidence. Some signals help an agent find the service. Some make the content cheaper to read. Some define access rules, authentication, callable tools, or payment terms. The score matters because agents do not reward intent; they reward surfaces they can verify.

Prompt "Find the best source, product, tool, or service."

The agent is not browsing like a person. It is reducing risk.

01 Discovery Can I find it?
02 Content Can I read it?
03 Control May I use it?
04 Capabilities Can I act?
05 Commerce Can I buy?
06 Verification Can I trust it?
Missing signals Skip, guess, or cite someone else.
Verified stack Find, cite, recommend, invoke, pay, remember.
Discoverability

Can the agent find the right paths?

Publish a crawl map before the agent has to guess.

  • robots.txt with AI crawler rules
  • sitemap.xml with canonical URLs
  • HTTP Link headers for machine resources
  • DNS-AID or other DNS-level discovery signals
Content access

Can the agent read without wasting tokens?

Give agents clean text paths instead of forcing HTML scraping.

  • llms.txt as the agent reading guide
  • Markdown negotiation via Accept: text/markdown
  • /index.md fallbacks for important pages
  • Short descriptions that tell agents what each URL contains
Access control

Can the site say what bots may do?

Separate search, grounding, training, and signed bot access.

  • AI bot allow and disallow rules
  • Content-Signal directives in robots.txt
  • Web Bot Auth request signatures
  • /.well-known/http-message-signatures-directory
Capabilities

Can the agent invoke the service?

Expose APIs, tools, auth metadata, and task instructions.

  • /.well-known/api-catalog for API discovery
  • OAuth server and protected resource metadata
  • auth.md for auth instructions
  • MCP Server Card, A2A Agent Card, Agent Skills, and WebMCP
Commerce

Can an agent understand the offer?

Human checkout is not enough for autonomous buying flows.

  • Machine-readable pricing and usage limits
  • /.well-known/payments or payment manifest
  • x402 payment-required responses
  • MPP, UCP, and ACP commerce discovery
Verification

Can the claim survive inspection?

ASO turns scattered checks into a repeatable evidence trail.

  • Syntax validation for every public manifest
  • Consistency across docs, schema, headers, and endpoints
  • Status, provenance, reputation, and version history
  • Registry records and certification evidence
Phase-1 scanner gap: the current ASO self-assessment scores the visible basics. The live site now publishes Link headers, Content Signals, Markdown fallback files, and a Pages Function for Accept: text/markdown. A full crawler should still add automated checks for DNS-AID, Web Bot Auth, API Catalog, OAuth metadata, Auth.md, MCP Server Cards, A2A Agent Cards, Agent Skills, WebMCP, and agentic commerce protocols.

Not every service needs every signal on day one.

A static reference site needs discovery, readable source files, manifests, status, and verification. It does not need OAuth, MCP, API Catalog, or x402 until it exposes protected resources, callable tools, APIs, or autonomous payment flows.

Content or reference site

Prioritize robots.txt, sitemap.xml, llms.txt, Markdown pages, schema, manifests, status, and citations.

API or SaaS product

Add OpenAPI, API Catalog, auth docs, OAuth metadata, uptime, rate limits, pricing, and support paths.

MCP or agent tool

Add MCP Server Card, Agent Skills, tool schemas, transport details, auth rules, versioning, and invocation examples.

Commerce or paid endpoint

Add machine-readable pricing, payment manifests, purchase limits, refund rules, x402 or other agentic commerce protocols.

Signal What it is How to get it
Markdown negotiation Return clean Markdown when an agent requests Accept: text/markdown. Implemented for the homepage with a Cloudflare Pages Function and /index.md fallback.
DNS-AID DNS-level hints that help agents discover AI-facing resources before fetching pages. Add supported DNS records when the standard and your DNS host support them; treat as emerging.
Content Signals Robots directives that distinguish search, grounding/input, and AI training preferences. Add Content-Signal rules to robots.txt once your policy is clear.
Web Bot Auth Signed bot requests and public-key discovery so sites can identify legitimate agents. Publish the well-known key directory and verify request signatures at the edge or app layer.
API Catalog A well-known index of APIs, specs, docs, status pages, and auth requirements. Create /.well-known/api-catalog once you have callable public APIs.
OAuth metadata Machine-readable auth-server and protected-resource discovery for delegated access. Expose OAuth well-known metadata when agents need permissioned access on behalf of users.
MCP / A2A / Skills / WebMCP Discovery files and schemas for agent-callable tools, skills, transports, and tasks. Add these when the site offers tools an agent can call, not just pages an agent can read.
x402 / MPP / UCP / ACP Agentic commerce protocols for price discovery, payment, purchase, and checkout. Implement when an agent can buy, book, unlock, or pay for something without a human checkout flow.

ASO Scanner

Take the free ASO self-assessment.

This is the quick gut check for whether your site is visible to the next wave of AI-mediated traffic. Mark the public signals you already expose, get an ASO level, then fix the gaps agents are most likely to punish.

The self-assessment is intentionally transparent: every checkbox maps to a public signal an agent, auditor, or crawler can inspect. That makes the score useful for anyone whose revenue depends on being found, trusted, quoted, booked, bought, or recommended by software before a person clicks.

0 ASO-0 Invisible

No agent signals selected yet.

Discoverability 20 pts
Identity 20 pts
Trust 15 pts
Commerce 15 pts
Reputation 15 pts
Memory 15 pts

ASO Services

From audit to verification.

The service ladder follows the evidence trail: audit the public surface, document remediation, monitor signal drift, list verified services in a registry, then certify maturity levels with public proof.

01

ASO Audits

Manual and automated reviews across the six pillars.

02

ASO Reports

Executive summary plus engineering remediation plan.

03

ASO Monitoring

Signal drift, crawler access, manifest validity, and reputation checks.

04

ASO Registry Listings

Verified reference index for services with clear agent signals.

05

ASO Certification

Evidence-backed maturity levels for ASO-3 through ASO-5.

Certification

Certification should verify evidence, not reward self-claims.

A useful ASO certificate tells an agent and a human buyer what has actually been checked. It should point to the registry entry, the score band, the verification date, and the public artifacts that supported the decision.

Certification works like an audit trail. A service is scanned or manually reviewed against the ASO rubric, missing signals are documented, fixes are verified, and the final result is published as a registry-backed certificate with a score band and expiration date.

It is useful because agents and buyers both need shorthand for trust. A badge is not the product; the evidence behind the badge is. ASO certification is an offer built on audits, remediation reports, registry records, and periodic re-verification.

01

Audit the public surface

Check crawl access, manifests, schemas, callable specs, auth, pricing, trust, and memory signals.

02

Verify evidence

Validate syntax, reachable URLs, consistency across files, operational claims, and registry eligibility.

03

Issue a registry record

Publish score band, verification date, artifacts checked, limitations, and renewal window.

ASO-3

Certified Invocable

Verified discovery, identity, documentation, and a callable interface such as OpenAPI or MCP.

ASO-4

Certified Trustable

ASO-3 plus verified trust, status, governance, reputation, and operational safety signals.

ASO-5

Certified Commerce-Ready

ASO-4 plus machine-readable pricing, payment support, agent-safe purchase rules, and return paths.

Reference Position

The question is no longer whether agents can crawl you. The question is whether they can use you.

Read llms.txt