[BUG] opusplan setting doesn't switch to Opus during plan mode

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 using "model": "opusplan" in settings, Claude Code does not switch to the Opus model during plan mode. The model remains on Sonnet throughout the planning session.

Expected Behavior

Claude should report running on Opus 4.5 during plan mode.

Additional Context

• Manual switching works: /model opus and /model sonnet correctly switch to the respective Bedrock ARNs
• Using AWS Bedrock inference profiles (not direct Anthropic API)
• Claude Code version: 2.1.2

Question

Is opusplan supported when using custom Bedrock ARNs via ANTHROPIC_DEFAULT_OPUS_MODEL? If not, please document this limitation.

What Should Happen?

Claude reports running on Sonnet 4.5 even while in plan mode. The automatic model switch isn't happening.

Error Messages/Logs

Steps to Reproduce

Steps to Reproduce

1. Set "model": "opusplan" in settings
2. Enter plan mode (/plan or start a planning task)
3. Ask Claude which model it's running on or run /status
4. Set "model": "opusplan" in settings
5. Enter plan mode (/plan or start a planning task)
6. Ask Claude which model it's running on or run /status

Claude Model

Other

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.2

Platform

AWS Bedrock

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

Configuration

~/.claude/settings.json:
{
"env": {
"ANTHROPIC_DEFAULT_SONNET_MODEL": "arn:aws:bedrock:us-east-1:...:inference-profile/global.anthropic.claude-sonnet-4-5-20250929-v1:0",
"ANTHROPIC_DEFAULT_OPUS_MODEL": "arn:aws:bedrock:us-east-1:...:inference-profile/global.anthropic.claude-opus-4-5-20251101-v1:0"
},
"model": "opusplan"
}