[BUG] @ file reference autocomplete doesn't index files in additionalDirectories

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?

Environment:

• Claude Code version: 2.0.29
• OS: macOS 14.5 (23F79)
• Darwin: 23.5.0

Configuration:
Project settings file: .claude/settings.json
{
"permissions": {
"additionalDirectories": [
"/Users/<username>/git/project/domain",
"/Users/<username>/git/project/other_domain"
]
}
}

Actual Behavior:

• Autocomplete only shows files from the primary working directory
• Files in additionalDirectories are not suggested in autocomplete
• Manually typing the full path (absolute or relative) DOES work, confirming the directories are accessible

Workaround:
Manually type the full relative or absolute path without relying on autocomplete.

What Should Happen?

Expected Behavior:
When typing @ in the chat input, autocomplete should suggest files from both:

• The primary working directory (/Users/<username>/git/project/domain/root/)
• Additional directories configured in additionalDirectories

Error Messages/Logs

Steps to Reproduce

Steps to Reproduce:

1. Configure additionalDirectories in .claude/settings.json
2. Restart Claude Code
3. Type @ in the chat input
4. Try typing a path that starts with a directory from additionalDirectories (e.g., @../domain/)
5. Observe no autocomplete suggestions appear

Claude Model

Sonnet (default)

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.0.29

Platform

Other

Operating System

macOS

Terminal/Shell

IntelliJ IDEA terminal

Additional Information

_No response_