AI Coding Agents Need an Egress Firewall? A Default-Deny Playbook for Agent Traffic
Coding agents decide at runtime what to call, so the boundary has to sit outside the agent. A sysadmin's guide to default-deny egress: the agent sandbox defaults for Claude Code, Codex, ChatGPT Work, and Docker Sandboxes, the firewall and proxy layers that enforce allowlists, and where egress controls still leak.