{"version":"2.1.238","anchor":"proxy-refusals-no-longer-look-like-anthropic-blocking-you","canonical_anchor":"proxy-refusals-no-longer-look-like-anthropic-blocking-you","heading":"Proxy refusals no longer look like Anthropic blocking you","tier":"notice","area":"Internals","scope":null,"heads_up":null,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.238\/e\/proxy-refusals-no-longer-look-like-anthropic-blocking-you","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.238","markdown":"### Proxy refusals no longer look like Anthropic blocking you\n\nProxy tunnel refusals now name a CDN, VPN or firewall instead of looking like an Anthropic block.\n\n**What**\n\nWhen a corporate proxy or CDN refuses the CONNECT tunnel, the error now says so instead of surfacing as an Anthropic 403. The failure carries code `ERR_PROXY_TUNNEL` plus the CONNECT status and headers, and the explanation names a CDN or a VPN\/firewall refusing the request before it reached Anthropic.\n\n**Details**\n\n- A classifier inspects `request-id`, `cf-ray` and `server` headers to label the refusal as coming from the origin, a Cloudflare-like intermediary, or some other intermediary.\n- Header sniffing gained a separate `x-proxy-error` reader alongside the existing `x-deny-reason`.\n- Reachable in this build with no flag.\n\n**Evidence**\n\n`ERR_PROXY_TUNNEL`\n\n- Area: Internals\n- Tier: You'll notice\n- Useful: 4\/5\n- Signal: 2\/5"}