New gateway mode lets an outbound proxy be the sole network security boundary

What

A new environment variable, CLAUDE_GATEWAY_PROXY_IS_EGRESS_BOUNDARY, lets a gateway deployment tell Claude Code that all outbound network requests should be handed directly to an upstream HTTPS/HTTP proxy (the one set via HTTPS_PROXY/HTTP_PROXY), relying on that proxy's own allowlist. When this is active, Claude Code skips its own local DNS resolution and loopback/SSRF (server-side request forgery) safety checks and just passes hostnames straight through to the proxy.

This mode refuses to turn on, and logs a warning explaining why, in three cases:

• no HTTPS_PROXY/HTTP_PROXY is configured
• CLAUDE_GATEWAY_ALLOW_LOOPBACK is also set
• NO_PROXY/no_proxy is non-empty

Why

This lets administrators who already enforce network restrictions at their proxy avoid redundant or conflicting checks from Claude Code itself, while the safeguards prevent the setting from silently weakening security in setups where no proxy is actually in place to do that job.