L1

randomuser.me.

level 1: basic accessibility

Random User Generator is a free, open-source API that provides randomly generated user data. It returns user information in JSON, XML, CSV, or YAML formats, including names, photos, addresses, and contact details. You can use it by making an AJAX call to the API endpoint (randomuser.me/api/) and parsing the returned data.
Uses semantic HTML elements (header, nav, main, article, section, footer) instead of just divs PASS
Has proper meta tags (title, description, og:tags, twitter:card) PASS
Includes Schema.org JSON-LD structured data FAIL
Does not block automated access with CAPTCHAs on public content PASS
Content is server-side rendered (visible in HTML source, not just JS-rendered) PASS
Uses clean, readable URLs (no excessive query params or hash fragments) PASS
Has a robots.txt that allows legitimate bot access PASS
Provides an XML sitemap FAIL
Has a /llms.txt file describing the site for LLMs FAIL
Publishes an OpenAPI/Swagger specification for its API FAIL
Has comprehensive, machine-readable documentation FAIL
Primary content is text-based (not locked in images/videos/PDFs) PASS
Provides a structured REST or GraphQL API PASS
API returns JSON responses with consistent schema PASS
API supports search and filtering parameters FAIL
Has an A2A agent card at /.well-known/agent.json FAIL
Rate limits are documented and return proper 429 responses with Retry-After FAIL
API returns structured error responses with error codes and messages FAIL
Provides an MCP (Model Context Protocol) server FAIL
Supports WebMCP for browser-based agent interaction FAIL
API supports write operations (POST/PUT/PATCH/DELETE), not just reads FAIL
Supports agent-friendly authentication (API keys, OAuth client credentials) FAIL
Supports webhooks for event notifications FAIL
Write operations support idempotency keys FAIL
Supports event streaming (SSE, WebSockets) for real-time updates FAIL
Supports agent-to-agent capability negotiation FAIL
Has a subscription/management API for agents FAIL
Supports multi-step workflow orchestration FAIL
Can proactively notify agents of relevant changes FAIL
Supports cross-service handoff between agents FAIL