SKU.md
A simple, open draft for AI-readable product catalogs,
built for merchants to publish themselves.
Think of SKU.md as a catalog brief for agents: one predictable place to discover categories, representative products, policies, AI usage, and the live data sources behind them.
---schema_version: "sku.md/1.0"site_name: "Example Outdoor Gear"site_url: "https://www.example-outdoor.com"last_updated: "2026-07-16T08:00:00+08:00"update_frequency: "weekly"languages: ["zh-CN", "en-US"]currency_default: "USD" ai_usage: training: "disallow" retrieval_answer: "allow" citation_required: true agentic_checkout: "unsupported" capabilities: self_hosted: schema_jsonld: status: "live" note: "Each product detail page embeds schema.org/Product + Offer JSON-LD in <head>, including real-time price and availability" # Additional capabilities follow---Why SKU.md?
llms.txt maps a whole site. Product JSON-LD, sitemaps, and commerce feeds carry detailed or live product data.
SKU.md fills the layer between them: a concise catalog overview with product context, policies, AI permissions, and pointers to the sources an agent should trust next.
It is intentionally separate to:
Give agents one predictable, merchant-controlled catalog summary.
Keep descriptions factual while live price and stock stay in real-time sources.
Declare what is self-hosted, platform-gated, live, planned, or unsupported.
The draft does not replace any protocol in the commerce stack. It makes their roles and availability easier to discover from one open, self-published file.
One SKU.md connects the commerce stack
SKU.md does not replace existing standards. It tells agents which layers a merchant publishes and where to find them.
Examples
---schema_version: "sku.md/1.0"site_name: "Example Outdoor Gear"site_url: "https://www.example-outdoor.com"last_updated: "2026-07-16T08:00:00+08:00"update_frequency: "weekly"languages: ["zh-CN", "en-US"]currency_default: "USD" ai_usage: training: "disallow" retrieval_answer: "allow" citation_required: true agentic_checkout: "unsupported" capabilities: self_hosted: schema_jsonld: status: "live" note: "Each product detail page embeds schema.org/Product + Offer JSON-LD in <head>, including real-time price and availability" sitemap: status: "live" url: "https://www.example-outdoor.com/sitemap-products.xml" webmcp: status: "unsupported" scope: "/products/*" tools: [] platform_gated: acp_product_feed: status: "planned" url: "https://www.example-outdoor.com/feeds/acp-products.jsonl.gz" acp_checkout: status: "unsupported" ucp_catalog: status: "planned" well_known: "https://www.example-outdoor.com/.well-known/ucp" ucp_checkout: status: "unsupported" contact: business_email: "support@example-outdoor.com" merchant_of_record: "Example Outdoor Gear Inc."--- # Example Outdoor Gear > An independent store specializing in lightweight outdoor gear across three categories:> tents, sleeping bags, and hiking backpacks. Products focus on lightweight designs under 750g, are manufactured by partner factories in Vietnam and China, and range from $39–$459. ## Categories - [Ultralight Tents](https://www.example-outdoor.com/collections/tents): 12 models available, weighing 1.1–2.3kg, priced at $129–$459- [Down Sleeping Bags](https://www.example-outdoor.com/collections/sleeping-bags): 8 models available, rated from -5°C to 10°C, priced at $89–$329- [Hiking Backpacks](https://www.example-outdoor.com/collections/backpacks): 15 models available, with capacities from 20L–65L, priced at $39–$189 ## Featured SKUs | SKU ID | Name | Key Specifications | Reference Price Range | Product Page | Detail Data ||---|---|---|---|---|---|| TENT-ULT-02 | UltraLight 2P Tent | Weight 1.35kg, 20D silicone-coated nylon, 3000mm hydrostatic head, includes 8 stakes | $259–$299 | [Details](https://www.example-outdoor.com/products/tent-ult-02) | Embedded JSON-LD || BAG-DOWN-700 | 700-Fill-Power Down Sleeping Bag | Lower temperature limit -5°C, weight 890g, 90/10 white goose down, waterproof shell | $199–$249 | [Details](https://www.example-outdoor.com/products/bag-down-700) | Embedded JSON-LD || PACK-45L-AIR | Air Series 45L Backpack | Empty weight 980g, aluminum alloy suspension system, rain cover included | $129–$159 | [Details](https://www.example-outdoor.com/products/pack-45l-air) | Embedded JSON-LD || TENT-SOLO-01 | Solo One-Person Tent | Weight 890g, integrated fly and inner tent, rated for Force 8 winds | $189–$219 | [Details](https://www.example-outdoor.com/products/tent-solo-01) | Embedded JSON-LD || BAG-SYN-COMFORT | Synthetic Comfort Sleeping Bag | Lower temperature limit 5°C, weight 1.2kg, suitable for beginners and humid climates | $89–$109 | [Details](https://www.example-outdoor.com/products/bag-syn-comfort) | Embedded JSON-LD | *For the complete SKU list and real-time price and availability, refer to `sitemap-products.xml` or the JSON-LD on each product detail page. This table is a selected summary and may not reflect the latest catalog changes.* ## FAQ **Q: How long does shipping take?**A: Orders ship the same day from our warehouse in mainland China. Standard shipping to the United States and Europe takes 7–12 business days, and tracking is provided. **Q: Do you accept returns and exchanges?**A: Unopened items may be returned or exchanged within 30 days of delivery. The buyer covers shipping unless the item has a quality issue, in which case the seller covers shipping both ways. **Q: Are the tents and sleeping bags certified waterproof?**A: All tent flysheets have a hydrostatic head rating of at least 3000mm, meeting the Chinese national standard for lightweight waterproof equipment. See each product page for its exact rating. **Q: Can AI shopping assistants place orders directly?**A: Not currently. See `ai_usage.agentic_checkout: unsupported`. Direct users to the product page to complete their purchase. ## Policies - Shipping: Ships from a warehouse in mainland China; standard delivery takes 7–12 business days and is available to most major countries- Returns: Unopened items may be returned or exchanged within 30 days; return shipping is free for quality issues- Warranty: One year for the main body of tents and backpacks; six months for sleeping bags ## Changelog - 2026-07-16: Initial release covering 35 SKUs across three categories, with five representative products featured Root catalog
A concise site-wide catalog at /sku.md with categories, selected products, policies, and data pointers.
Category catalog
Optional nested files let large catalogs publish fresher, category-specific guidance with nearest-file precedence.
AI usage
Required declarations make training, retrieval, citation, and agentic checkout boundaries explicit.
Capabilities
One manifest distinguishes self-hosted product data and actions from platform-gated feeds and checkout.
How to use SKU.md?
1. Prepare live product truth
Publish Product and Offer JSON-LD on product pages and maintain a product sitemap. SKU.md summarizes the catalog; these sources remain authoritative for live details.
2. Add /sku.md
Create a UTF-8 Markdown file at the site root with the required frontmatter, categories, representative products, FAQs, policies, and changelog.
3. Make it discoverable
Allow root and nested sku.md paths in robots.txt, add a SKU Catalog link to llms.txt, and optionally expose a sku-catalog link element on product pages.
4. Keep it current, then split only when needed
Update capability status and catalog summaries on the declared cadence. Add category-level sku.md files only when catalog size, update cadence, or capability differences justify them.
About
SKU.md is an original open draft informed by established discovery and commerce mechanisms, including robots.txt, llms.txt, Schema.org, WebMCP, ACP, and UCP.
Version 1.1 is a draft proposal, not a formally adopted standard. Its goal is to make a practical merchant-controlled catalog summary available today while keeping live commerce truth and transaction authority in the systems designed for them.
FAQ
Is SKU.md an official standard?
No. sku.md/1.0 is an original proposal, not an industry-adopted standard. The draft is published openly so merchants, platforms, and agent builders can evaluate and improve it.
Are there required fields?
Yes. The draft requires schema_version, site identity, last_updated, the complete ai_usage group, and the capabilities manifest. Missing capabilities should be declared as unsupported instead of being omitted.
Should price and inventory go in SKU.md?
No. SKU.md should point to live product pages, Product and Offer JSON-LD, sitemaps, or approved feeds. Keeping volatile values out of the summary reduces the chance that an agent quotes stale commerce data.
Does SKU.md enable agentic checkout?
Not by itself. It only declares whether ACP or UCP checkout is live, planned, or unsupported. Checkout still requires the relevant platform integration, merchant approval, and real-time transaction flow.
How do category files inherit settings?
A nested category sku.md inherits ai_usage and capabilities from the root file unless it explicitly overrides them. The nearest file applies, while every nested file maintains its own last_updated value.
How often should I update it?
Update it when categories, policies, representative products, or capability status changes. Declare daily, weekly, or on-change in update_frequency, and record structural revisions in the changelog.
How do agents discover SKU.md?
Serve it at the site root, allow root and nested sku.md paths in robots.txt, add a SKU Catalog link to llms.txt, and optionally expose a sku-catalog link element on product pages.
<link rel="sku-catalog" href="/sku.md">