Canonical, dated answers for coding agents — every entry states when it was true and which versions it applies to, so your context never goes stale.
nginx 1.30.x (from 2026-04-14, latest 1.30.5 on 2026-09-15) is the stable branch and 1.31.6 is mainline. Since 1.29.7 the proxy defaults to HTTP/1.1 with upstream keepalive. 2026 brought many worker-memory CVEs, so patch.