[BUG] Support HTTPS proxy (https:// scheme) for HTTPS_PROXY environment variable

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?

Claude Code 2.x does not support https:// scheme in the HTTPS_PROXY environment variable, resulting in ERR_SOCKET_CLOSED error when trying to connect.

What Should Happen?

Claude Code should support HTTPS_PROXY=https://... either by using a library like https-proxy-agent internally, or by documenting the limitation with a clear error message

Error Messages/Logs

Unable to connect to Anthropic services

Failed to connect to api.anthropic.com: ERR_SOCKET_CLOSED

Please check your internet connection and network settings.

Steps to Reproduce

``zsh
HTTPS_PROXY="https://user:pass@proxy-host:port" claude login
``

#### Result

 Unable to connect to Anthropic services. Failed to connect to api.anthropic.com:  ERR_SOCKET_CLOSED

Claude Model

Not sure / Multiple models

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.193

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

## Environment

• Claude Code: 2.1.193
• OS: macOS 26 (arm64)
• Shell: zsh

## Root cause

The proxy server requires a TLS connection (https:// scheme). Node.js built-in HTTP modules do not support TLS-in-TLS tunneling (connecting to the proxy itself via TLS, then sending a CONNECT request inside that TLS channel). curl supports this since 7.52.0, but Node.js core does not.

## Workaround

Using socat as a local TCP bridge that handles TLS to the proxy:

``
socat TCP-LISTEN:3277,fork,reuseaddr "SSL:proxy-host:port,verify=0" &
HTTPS_PROXY="http://user:pass@127.0.0.1:3277" claude login
``