[FEATURE] Expose --add-dir functionality via environment variable

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

I manage a remote development environment where a shared drive is mounted to user's workspaces. I'd like to be able to easily share Claude skills with this shared drive.

This functions with the claude --add-dir <shared dir> flag.

Proposed Solution

I'd like to be able to automatically set this via environment variable so that I don't need to manually add the directory whenever I launch claude. Ex:

# In my ~/.bashrc or elsewhere
CLAUDE_CODE_ADDITIONAL_DIRECTORIES=$HOME/share/utils

Then when I run claude, the additional directory is picked up automatically.

Alternative Solutions

_No response_

Priority

Low - Nice to have

Feature Category

CLI commands and flags

Use Case Example

_No response_

Additional Context

_No response_