The Website Specification

A new website specification, "What a good website does," has been published as a platform-agnostic technical standard covering ten categories including SEO, accessibility, security, and agent readiness. The specification maps each requirement to widely-accepted standards from organizations like WHATWG, W3C, and IETF, and is available as an open MCP server for AI agents to query. The project aims to provide a definitive, community-maintained checklist for building modern websites that serve both humans and automated agents.

What a good website does. A platform-agnostic specification of the technical features every decent website should have — from <title to /.well-known/security.txt , from WCAG contrast to llms.txt . Written for humans and agents. Categories Ten areas, mapped to widely-accepted standards. All topics → /spec/ - Foundations 14The HTML, head, and document basics every page needs. - SEO 13Search visibility — robots.txt, sitemaps, canonicals, structured data. - Accessibility 20WCAG-aligned rules so people of all abilities can use the site. - Security 12Headers, transport, and policies that keep visitors safe. - Well-Known URIs 9Standard, agreed-upon paths under /.well-known/. - Agent Readiness 18Things that make a site legible to AI agents and crawlers. - Performance 19Core Web Vitals, caching, images, fonts, network behaviour. - Privacy 6Consent, signals, and respecting visitor choice. - Resilience 5Graceful failure — error pages, offline, redirects. - Internationalisation 12Language, locale, direction, and translated content. Standards, not opinions Each topic links back to the source standard — WHATWG, W3C, IETF RFCs, WCAG, MDN, and the organisations defining the modern web. Platform agnostic Whether you ship WordPress, Drupal, TYPO3, Next.js, Astro, Hugo, a Django app, or plain HTML, the spec is the spec. Implementation hints follow it, not the other way round. Built in the open Every page has an Edit on GitHub https://github.com/jdevalk/specification.website link. PRs welcome. Sources credited on every page. Let your agent query the spec. The whole spec is available as an open MCP https://modelcontextprotocol.io/ server — read-only, no auth — plus a published Agent Skill /.well-known/agent-skills/specification-website/SKILL.md that teaches any compatible agent when and how to use it. Per-page Markdown is available via /llms.txt and Accept: text/markdown on any spec URL. { "mcpServers": { "specification-website": { "transport": "http", "url": "https://mcp.specification.website/mcp" } } } How to use this site - 01 Audit Run through the checklist /checklist/ . Each item is a “does the site do this — yes or no.” - 02 Learn Click into any item for what it is, why it matters, and how to implement it. - 03 Improve Found a gap, a stale fact, or a missing topic? Open a PR. Sources required.