# Known-Good

> An index of websites verified to be usable by AI agents. We read every robots.txt in a
> full public crawl of the web, find the sites that invite agents in, then probe them live
> to check whether they built anything an agent can actually use. About half had.

Known-Good grades sites against a published rubric and dates every claim. A declaration is
not a capability: we test rather than trust the label. Verification of the full index is in
progress; this site is v0.1.

We declare `ai-input=yes` and `ai-train=no`. Agents are welcome to read this site and use it
to answer someone's question. Please do not use it as training data.

## Pages

- [Homepage](https://knowngood.sh/index.md): what we found, and the three things that make a site agent-ready. Markdown twin of the homepage.
- [Crawler information](https://knowngood.sh/bot.md): what our KnownGood-Verifier crawler does, what it fetches, and how to block it. Markdown twin of /bot.

## Machine endpoints

- [Crawler IP ranges](https://knowngood.sh/bot/ips.json): the published source addresses our verifier crawls from, so you can confirm a request is genuinely ours.
- [robots.txt](https://knowngood.sh/robots.txt): our own content signals, declared honestly.

## Key findings

- 83,900,812 robots.txt files read across a full public crawl of the web.
- 2,171,626 of them carry a content signal — a declared stance on AI use.
- 57,740 domains explicitly welcome AI agents to read them. That is roughly 1 in 1,453.
- About 1 in 2 of the sites that decided for themselves have built something an agent can use.
- 86% of all content-signal declarations are one CDN's default rather than a decision anyone made.

## Contact

- Free 30-minute agent-readiness review: https://cal.com/knowngood.sh/30min
- Crawler questions or opt-out: bot@knowngood.sh
- Everything else: hello@knowngood.sh

## Not yet live

Content negotiation on the `Accept` header, the search API, and an MCP server arrive with v1.
We do not list endpoints that do not exist.