What it is
A new env var lets a gateway proxy handle outbound address safety checks itself instead of Claude Code
Not Anthropic's. This is the line from the earliest changelog entry here that named it, v2.1.277.
Presence across releases
1Build by build
2One row per release since the first build this name was read out of. Absent means the build was read and the name was not in it, never mined means no bundle for that release was ever archived, and a declared type or a default is only ever what that release's own bundle stated.
First cited
2The earliest release whose published evidence quoted CLAUDE_GATEWAY_PROXY_IS_EGRESS_BOUNDARY was v2.1.277, 18 Sep 2026. That is the oldest release this project wrote about it, so it is a floor on the name's age and not the release that introduced it. It is not a presence reading: which builds carried the name is the table above.
Names beside it
Every environment variable in the inventory starting claude_gateway, up to twelve of them.
CLAUDE_GATEWAY_ALLOW_LOOPBACKThe gateway can authenticate callers with Anthropic-issued JWTs verified against a remote key endpoint. v2.1.160
CLAUDE_GATEWAY_DRAIN_TIMEOUT_MSclaude gateway now shuts down gracefully on SIGTERM/SIGINT instead of exiting abruptly v2.1.274
CLAUDE_GATEWAY_LOG_LEVELNo description from anybody. v2.1.162
Read out of the published npm bundle release by release, and out of Anthropic's own documentation as this site captured it. Nothing on this page is a description anybody here wrote about what the environment variable does. All environment variables.