7 signals. 1 score. Free, no sign-up.
Every URL is checked for seven signals that AI agents look for when deciding whether to work with a site. Max score is 100. Sites must expose at least one hard signal (API/OpenAPI/ai-plugin/MCP) to appear in the main directory.
| Signal | What it means | Points |
|---|---|---|
llms.txt | Markdown index for LLMs | 25 |
ai-plugin.json | OpenAI plugin manifest | 20 |
OpenAPI | Machine-readable API spec | 20 |
structured API | Discoverable REST/GraphQL surface | 15 |
MCP server | Model Context Protocol endpoint | 10 |
robots.txt AI | Explicit policy for AI crawlers | 5 |
Schema.org | Structured data markup | 5 |