A BGP looking glass server accessible over a browser or through curl.
How is the 'Requested from' IP determined?
This site goes though Cloudflare which encodes the requesting IP in the header. Sometimes you may go through a proxy beforehand. If that's the case I attempt to extract the original IP from that header, but I can only do that if it's still there.
Is this information live?
All information is obtained from a live BGP server so is live at the point of your request.
What does ROA UNKNOWN mean?
UNKNOWN simply means there is no ROA for that prefix. It's a valid state.