[DOCS] HTTP_PROXY env var can also be used to redirect sandbox traffix

Documentation Type

Missing documentation (feature not documented)

Documentation Location

https://code.claude.com/docs/en/sandboxing

Section/Topic

Proxy Configuration (Environment Variables)

Current Documentation

Claude instructions for enterprise network configuration tell that Claude Code respects standard proxy environment variables., which includes HTTP_PROXY and HTTPS_PROXY.

Claude instructions for sandboxing tell that For organizations requiring advanced network security, you can implement a custom proxy to: and then explain localhost httpProxyPort.

What's Wrong or Missing?

It is unclear from the documentation whether sandboxed tool calls will also respect HTTPS_PROXY and HTTP_PROXY variables passed to Claude Code. The mere existence of httpProxyPort suggests otherwise, but our experiments on MacOS indicate that the sandboxed traffic is indeed proxied.

Suggested Improvement

If the env var proxying is supported in sandboxes, it would be great to document it in https://code.claude.com/docs/en/sandboxing as a feature people can rely on. This feature allows authentication, unlike httpProxyPort. (At the very least, we find this feature really valuable.)

It would be also great to document which specification takes precedence, httpProxyPort in settings or HTTP_PROXY env var.

Impact

High - Prevents users from using a feature

Additional Context

_No response_