[BUG] Claude Code forces Haiku for bash tool operations and freezes, ignoring model selection entirely.

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 forces Haiku for bash tool operations and freezes, ignoring model selection entirely.

Debug logs consistently show:
Tool search disabled for model 'claude-haiku-4-5-20251001'

This happens regardless of:

• Max subscription (verified, UI shows "Claude Max")
• Extra usage enabled
• Model set to Opus in settings.local.json
• Fresh account creation

The Freeze Pattern

• Stream starts, receives first chunk
• Then stalls indefinitely during bash tool execution
• Haiku is being called even when Opus is selected

Environment

• Claude Code 2.1.27
• macOS
• Max subscription, extra usage ON

Related

#17966

What Should Happen?

When Opus 4.5 is selected (via /model or settings.local.json), all operations including bash tool calls should use Opus, not Haiku. The model selection should be respected across the entire session without silent downgrades or freezing.

Error Messages/Logs

Steps to Reproduce

1. Fresh install Claude Code 2.1.27 on macOS
2. Clear any existing auth:

• Delete ~/.claude.json
• Delete ~/.claude/ directory
• Remove keychain entries: security delete-generic-password -s "Claude Safe Storage" and security delete-generic-password -s "Claude Code-credentials"

1. Run claude and login with Max subscription account
2. Verify Max is recognized (header shows "Claude Max")
3. Run /model and select Opus 4.5 (or set in ~/.claude/settings.local.json)
4. Start any task that uses bash tools (e.g., "list files in this directory")
5. Observe: task freezes mid-execution
6. Check debug log: tail -50 ~/.claude/debug/latest
7. Debug log shows Haiku being used despite Opus selection:

Tool search disabled for model 'claude-haiku-4-5-20251001'

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.27

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_