Web fetching works again behind fake-IP proxies and on IPv6-only networks

What changed

The SSRF guard on @cherry/fetch, web_fetch, web search content extraction, and citation previews no longer treats the proxy fake-IP range (198.18.0.0/15) or NAT64 addresses as private. NAT64 targets are now judged by the IPv4 address they embed, and a hostname that returns several addresses connects through a public one instead of failing outright.

Why this matters to the user

Users running Clash/mihomo TUN, Surge Enhanced Mode, or any fake-IP proxy saw every fetch fail with Unsafe remote url: DNS resolved to local or private address. Users on IPv6-only or 464XLAT networks saw the same. Both now work.

What the user should do

Nothing — automatic. Localhost, RFC 1918, carrier-grade NAT, link-local (including cloud metadata at 169.254.169.254), multicast, broadcast, and the remaining reserved ranges are still rejected, including when reached through NAT64. A proxy configured with a fake-IP range other than the 198.18.0.0/15 default is still blocked.

Notes for release manager

Supersedes the "Clash Fake-IP addresses are still rejected" caveat in 2026-07-21-web-lookup-terminal-errors.md. The proxy limitation recorded in 2026-07-15-citation-preview-proxy-limit.md is unchanged — that one is about the Chromium session proxy, not the address filter.