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

[PhilMcDon]

Preflight Checklist

• I have searched existing issues and this hasn't been reported yet
• This is a single bug report (please file separate reports for different bugs)
• 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"
}

[github-actions]

Found 2 possible duplicate issues:

1. [Bug] Model configuration "opusplan" not recognized in plan mode #16183
2. Model setting in settings.json is ignored on startup - defaults to Sonnet instead of configured Opus #13242

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🤖 Generated with Claude Code

[win20]

Hi, trying to test out opusplan and have the same issue, only switching manually works, i switched to opusplan by doing /model opusplan and it "adds" the opusplan as a separate model.

Maybe I've missed an update or a doc entry, but this seems so contrived, why not just add an option so we can tell it what to use in plan mode and what to use in execution. I guess sub agents might be able to do the trick but it feels like a workaround for something that should have been simple.

And it doesn't help that they have a section for "opusplan" in their docs which implies it should be operational.

Any updates please?

[vananden]

yep, same experience here

[AnyCPU]

I use Claude Max subscription.

If I set a model as /model opusplan in Claude Code (2.1.45) and switch to Plan mode then I see latest Opus in a /context output, If I switch back from Plan mode then I see latest Sonnet.

If you set a Haiku model as default, then Sonnet will be active in Plan mode.

It should work in the same way for AWS.

Docs: https://code.claude.com/docs/en/model-config