What
An HTTP hook is a hook that sends data to a web address at a set moment in a session. When no proxy is in use, Claude Code now checks the hook's address against a list of blocked address ranges before sending. A proxy here means the sandbox's proxy or one set in your environment.
When the address falls in a blocked range:
- Claude Code always records it in usage data, with the reason, the hook's source and the mode.
- It refuses to send the hook only when a server-controlled switch is on. That switch is off unless it is turned on remotely.
Claude Code also now uses its own address lookup whenever no proxy is in use.
Why
This guards against hooks being pointed at addresses they should not reach, such as private network ones. By default it only records such cases rather than stopping them.