[BUG] no_proxy NO_PROXY for ANTHROPIC_BASE_URL ignored again starting in 2.1.92 (still broken in 2.1.206)

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

NO_PROXY is being ignored again. This is the third occurrence of essentially the same regression:

• #22752 — broke in 2.1.23, fixed in 2.1.38
• #39862 — broke again in 2.1.83, reported fixed in 2.1.117

I verified the following on my own installations (native install script, Linux):

| Version | NO_PROXY respected? |
|---|---|
| 2.1.38 | ✅ works |
| 2.1.91 | ✅ works |
| 2.1.92 | ❌ broken |
| 2.1.117 | ❌ broken |
| 2.1.206 (latest) | ❌ still broken |

Traffic to a host that is listed in NO_PROXY is still routed through HTTP_PROXY/HTTPS_PROXY,
causing connection failures / timeouts to that host instead of a direct connection.

What Should Happen?

Requests to hosts matching NO_PROXY should bypass HTTP_PROXY/HTTPS_PROXY entirely, as
documented.

Error Messages/Logs

Steps to Reproduce

1. Set up a forward proxy (HTTP_PROXY / HTTPS_PROXY).
2. Set NO_PROXY to include a host/domain that should bypass the proxy (e.g.

NO_PROXY=.example.com).

1. Point ANTHROPIC_BASE_URL (or another Claude Code network target) at a host covered by

NO_PROXY.

1. Run Claude Code on 2.1.38 or 2.1.91 — the proxy is correctly bypassed.
2. Run the same config on 2.1.92 or later (including current 2.1.206) — traffic goes through the

proxy and the connection fails/times out.

Claude Model

_No response_

Is this a regression?

Yes, this worked in a previous version

Last Working Version

2.1.91

Claude Code Version

2.1.206 (also reproduced starting at 2.1.92)

Platform

Other

Operating System

Ubuntu/Debian Linux

Terminal/Shell

WSL (Windows Subsystem for Linux)

Additional Information

_No response_