Agentic commerce glossary
Short definitions of the terms that come up when you make an ecommerce store work with AI agents, with links to the checks and guides that go deeper.
- A2A (Agent2Agent)
- A2A is an open protocol for AI agents to send tasks to other agents. An A2A server describes itself in an agent card at /.well-known/agent-card.json. Learn more
- Accessible name
- The text label that browsers expose for a button, link or form field in the accessibility tree, taken from its text, aria-label, aria-labelledby, label or alt text. Browsing agents use accessible names to tell controls apart. Learn more
- ACP (Agentic Commerce Protocol)
- ACP is an OpenAI and Stripe specification for product feeds, agentic checkout APIs and delegated payment. ACP feeds are pushed to OpenAI, so ACP support cannot be detected from a store URL. Learn more
- AEO (answer engine optimization)
- Answer engine optimization is the practice of structuring content so AI assistants and answer engines can quote it directly. It overlaps heavily with GEO. Learn more
- Agent card
- An agent card is a JSON document that describes an A2A agent: its name, skills, endpoint and authentication. It is served at /.well-known/agent-card.json, or at the legacy /.well-known/agent.json path. Learn more
- Agent-ready store
- An agent-ready (or agent-friendly) store is an online store that AI agents can reach without being blocked, read without running JavaScript, and operate through real HTML controls or a commerce API such as UCP. Learn more
- Agentic commerce
- Agentic commerce is shopping in which an AI agent searches, compares, builds a cart or checks out on behalf of a person. Protocols such as UCP, ACP and AP2 standardize parts of it. Learn more
- AI Catalog
- AI Catalog is a domain-level discovery file at /.well-known/ai-catalog.json that lists a site's AI interfaces, such as MCP server cards. It is new and rarely deployed on stores. Learn more
- AI search bot
- An AI search bot is a crawler that indexes pages so an AI assistant can cite or list them in answers, such as OAI-SearchBot, Claude-SearchBot or PerplexityBot. Blocking one hides a store from that assistant. Learn more
- AI shopping agent
- An AI shopping agent is an AI assistant that finds, compares or buys products for a person. It may read store pages, operate them in a browser, or call a commerce API. Learn more
- AP2 (Agent Payments Protocol)
- AP2 is a payment-authorization protocol, started by Google and donated to the FIDO Alliance in 2026, that uses signed mandates to prove a person authorized an agent purchase. Learn more
- API catalog
- An API catalog is a list of a site's public APIs published at /.well-known/api-catalog, as defined in RFC 9727. Entries usually link to OpenAPI descriptions. Learn more
- Browsing agent
- A browsing or computer-use agent is an AI agent that opens a website in a real browser and clicks, types and scrolls like a person. Most read the accessibility tree first and fall back to screenshots. Learn more
- Canonical URL
- The canonical URL is the preferred address of a page, declared with a link rel="canonical" tag. It tells crawlers and agents which of several duplicate URLs to treat as the real one. Learn more
- Checkout permalink
- A checkout permalink is a URL that builds a cart from item IDs and quantities and redirects to checkout, such as /buy/{variant_id}:{qty} in the UCP permalink format. Agents can hand it to a shopper to finish payment. Learn more
- GEO (generative engine optimization)
- Generative engine optimization is the practice of making content easy for AI answer engines like ChatGPT, Perplexity and Google AI Mode to find, read and cite. For stores, it starts with allowing AI search bots and server-rendering product facts. Learn more
- JSON-LD
- JSON-LD is a format for embedding structured data in a page inside a script type="application/ld+json" tag. It is the format Google recommends for schema.org Product markup. Learn more
- Landmark
- A landmark is a page region exposed in the accessibility tree, such as main, nav, header or footer. Landmarks let agents and screen readers jump straight to the main content. Learn more
- llms.txt
- llms.txt is a proposed Markdown file at the root of a site that gives AI agents a curated map of its most useful pages. Google Search does not use it. Learn more
- Markdown for Agents
- Markdown for Agents is a Cloudflare feature that returns a Markdown version of a page when a client sends Accept: text/markdown. Markdown uses far fewer tokens than HTML. Learn more
- MCP (Model Context Protocol)
- MCP is an open protocol that lets AI applications discover and call tools exposed by a server. Stores can expose catalog, cart and checkout tools over MCP, often as the transport behind a UCP profile. Learn more
- Medusa Store API
- The Medusa Store API is the storefront-facing REST API of a Medusa backend, used to list products, manage carts and place orders. Every /store request needs an x-publishable-api-key header. It isn't an agent protocol, but custom UCP, MCP or permalink routes can be built on top of it. Learn more
- MerchantReturnPolicy
- MerchantReturnPolicy is the schema.org type for describing a store's return window, fees and method in structured data. It can be attached to an Offer or to the Organization. Learn more
- OAuth protected resource metadata
- OAuth protected resource metadata is a JSON document at /.well-known/oauth-protected-resource, defined in RFC 9728, that tells agents which authorization server to use to sign in to an API. Learn more
- OfferShippingDetails
- OfferShippingDetails is the schema.org type for describing shipping cost, destinations and delivery times in structured data, attached to an Offer or the Organization. Learn more
- Product structured data
- Product structured data is schema.org Product and Offer markup that states a product's name, image, price, currency and availability in machine-readable form. Google's merchant listing requirements define the minimum fields. Learn more
- ProductGroup
- ProductGroup is the schema.org type for a product that comes in variants, such as sizes or colors. It lists each variant with hasVariant and names the varying properties with variesBy. Learn more
- robots.txt
- robots.txt is a file at the root of a site that tells crawlers which paths they may fetch, per user-agent token, as defined in RFC 9309. It can also list the site's sitemaps. Learn more
- Sitemap
- A sitemap is an XML file that lists a site's URLs so crawlers and agents can find every page. Stores should declare it in robots.txt and include product URLs. Learn more
- Soft 404
- A soft 404 is a missing page that returns HTTP 200 instead of 404, often by showing the homepage or an empty template. Crawlers and agents may then treat a dead product as live. Learn more
- SSR (server-side rendering)
- Server-side rendering means the server sends HTML that already contains the page content, instead of an empty shell filled in by JavaScript. Most AI crawlers do not run JavaScript, so they only see server-rendered content. Learn more
- Training crawler
- A training crawler collects web content to train AI models, such as GPTBot, ClaudeBot or Meta-ExternalAgent. Blocking one does not remove a store from AI answers. Learn more
- UCP (Universal Commerce Protocol)
- UCP is an open standard, published at ucp.dev, that lets agents discover a store's commerce capabilities at /.well-known/ucp and then search, build carts and check out over REST, MCP or A2A. Learn more
- User-initiated agent
- A user-initiated agent fetches a page in real time because a person asked an AI assistant to, such as ChatGPT-User, Claude-User or Perplexity-User. Some of these agents do not follow robots.txt. Learn more
- Web Bot Auth
- Web Bot Auth is an emerging IETF standard in which bots and agents sign their HTTP requests with HTTP Message Signatures so sites can verify who sent them. ChatGPT agent already signs its requests. Learn more
- WebMCP
- WebMCP is an experimental browser API that lets a web page register tools, such as search or add to cart, for in-browser AI agents to call. It is in a Chrome origin trial. Learn more
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Storefront skills for coding agents
Teach Claude Code, Cursor or Codex to build storefronts with the patterns these checks look for.
npx skills add medusajs/medusa-agent-skills