[BUG] Credentials stored in literal ~ subdirectory of CWD when CLAUDE_CONFIG_DIR is set

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?

When launching Claude Code with CLAUDE_CONFIG_DIR pointing to a custom config directory:
env CLAUDE_CONFIG_DIR="$HOME/.claude-personal" claude

Claude Code internally converts the path back to a ~-prefixed string (~/.claude-personal) and uses it in credential file paths without expanding ~. Since ~ is not expanded outside of a shell context, it is treated as a literal directory name relative to the current working directory.

The result: credentials are read from and written to <CWD>/~/.claude-personal/.credentials.json instead of the intended /home/user/.claude-personal/.credentials.json. A literal ~ subdirectory is created in whatever directory Claude Code was launched from.

This can be confirmed by deleting the <CWD>/~ directory — Claude Code immediately prompts for login again, proving that's where it was reading credentials from.

This does not reproduce when CLAUDE_CONFIG_DIR is unset (the default ~/.claude path is handled correctly).

What Should Happen?

CLAUDE_CONFIG_DIR is already set to a fully resolved absolute path. Claude Code should use it as-is for all file operations, including credential storage. If the path is ever converted to ~ shorthand internally, it must be re-expanded via os.homedir() or path.resolve() before any filesystem call.

CLAUDE_CONFIG_DIR=/home/user/.claude-personal → credentials at /home/user/.claude-personal/.credentials.json

Error Messages/Logs

Steps to Reproduce

1. Run Claude Code with an explicit config dir:

env CLAUDE_CONFIG_DIR="$HOME/.claude-personal" claude

1. Login when prompted
2. Observe credentials written to <CWD>/~/.claude-personal/.credentials.json instead of /home/user/.claude-personal/.credentials.json
3. Deleting the <CWD>/~ directory causes Claude Code to prompt for login again, confirming this is where credentials are being read from

Claude Model

Sonnet (default)

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.81 (Claude Code)

Platform

Anthropic API

Operating System

Ubuntu/Debian Linux

Terminal/Shell

Other

Additional Information

_No response_