[FEATURE] Allow combined Sonnet/Haiku usage similarly to opusplan
Status Fixed / completed
Maintainer reply ✓ Yes — km-anthropic
Workaround ✓ Mentioned in description ↑
Activity 12 comments · opened Oct 17, 2025 · closed Nov 24, 2025
💡 Likely answer: A maintainer (km-anthropic, contributor)
responded on this thread — see the highlighted reply below.
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
With the introduction of Haiku 4.5 it would be viable to use that for doing code changes based on planning executed by Sonnet. This currently requires manually switching between models, which is an extra step, can be forgotten, etc.
Proposed Solution
Introduce a new mode similar to what we had with opusplan, e.g. claude --model sonnetplan which would dynamically use Sonnet for planning and Haiku for editing
Alternative Solutions
A seemingly feasible workaround would be to override the default models via the env variables and switch to opusmode, but that's not available on the pro plan.
myUser@myMachine myFolder % export ANTHROPIC_DEFAULT_OPUS_MODEL=claude-sonnet-4-5
myUser@myMachine myFolder % export ANTHROPIC_DEFAULT_SONNET_MODEL=claude-haiku-4-5
myUser@myMachine myFolder % claude --model opusplan
Claude Pro users are not currently able to use Opus in Claude Code. The current model is now Sonnet.Priority
Medium - Would be very helpful
Feature Category
CLI commands and flags
Use Case Example
_No response_
Additional Context
_No response_
12 Comments
Found 2 possible duplicate issues:
This issue will be automatically closed as a duplicate in 3 days.
🤖 Generated with Claude Code
I'm not sure. The first mentioned ticket is not a duplicate, the second one seems related but that's a closed bug report, asking for a behavior that AFAIK doesn't exist. (And this ticket is about adding that behavior)
2.0.22: Set /model to Haiku. Then switch to plan mode and model will change from Haiku to Sonnet. So it appears they already implemented what you wanted.
That seems to contradict #9695 but I'll check tomorrow
Yeah, that's not working.
<img width="1227" height="504" alt="Image" src="https://github.com/user-attachments/assets/9651f2fa-2c9b-466e-887c-1d305943721c" />
Status: Feature is NOT implemented - only shows up in statusline JSON
The Haiku→Sonnet plan mode switching described in this feature request is not actually working. When Haiku 4.5 is set as default and plan mode is entered:
This is a bug in the JSON, not a proper feature implementation. This feature seems to remain unimplemented as of this test of v2.0.32
Bump for this features. New sonnetplan mode should be added.
Hi! Sometimes the model gets confused when it sees a different model string above. Instead I recommend clicking ctrl+O to deterministically find out what model was called. Here's a screenshot:
<img width="1778" height="452" alt="Image" src="https://github.com/user-attachments/assets/9f52b209-a4e8-45e0-9ea9-899039a4de69" />
Although the model says it's haiku, you can see the sampled model is sonnet (this is in Plan Mode, where it's automatically set as a default). We're working to better improve the model's identification of itself though!
Wow, I didn't know about this, and I can confirm that it works as you described.
No worries! It definitely is a bit confusing.
So the workflow now is
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