Show HN: A page that hides a sentence for AI and lets you check if it came back

The premise is web pages have two readers, people and the AI reading for people. Web pages can now be written more for the AI and less for people. It’s a companion to an earlier page about browser fingerprinting. (https://news.ycombinator.com/item?id=48062178)

On my page, the there’s a planted phrase for AI. As the site gets crawled, you can see if this phrase is ever returned by any AI summarizing the page. So there’s a couple things you can do on my page:

1. Ask any AI to summarize the URL, and check if the planted phrase has been read. 2. Create a short-lived link and paste into any chat. You will see which crawler reads it first, before anyone ever actually opens or clicks on the link. 3. Generate your own planted phrase and leave it for the next crawler.

On this page, I also look at one example, composio.dev/hermes which serves a block of instructions specifically for AI agents. It’s not malicious, and it’s good marketing but shows that web pages can now be created and written for two very different audiences.