Comment by sqs
That draft RFC you mention is superseded by https://agents.md. Now that Amp uses AGENTS.md (https://x.com/sqs/status/1957945824404729997), I made all the former agent file stuff on https://ampcode.com just redirect to https://agents.md.
Gotcha - this is what I had in my history: https://ampcode.com/AGENT.md
For me, that gives a 404 with no obvious way to get to https://agents.md, I think either a hyperlink or redirect would be nice to have as well.