Model incorrectly changes on agent switch using -m, but correctly sticks using config

[jdanbrown]

Description

Related issues from pre-1.0:

• Switch model for all agents #3028
• Model switch automatically when changing the mode #1661

Now in 1.0, if I set my model in the config file then the model correctly doesn't change when I switch agents:

1. In config opencode.jsonc, set "model": "anthropic/claude-sonnet-4-5"
   1. Run opencode → UI shows "Anthropic Claude Sonnet 4.5"
   2. Press tab to switch agents → UI still shows "Anthropic Claude Sonnet 4.5" — correct
2. In config opencode.jsonc, set "model": "openai/gpt-5"
   1. Run opencode → UI shows "OpenAI GPT-5"
   2. Press tab to switch agents → UI still shows "OpenAI GPT-5" — correct

But if I instead set my model using -m/--model on the command line, then when I switch agents the model incorrectly changes to the last-used model:

1. Disable config "model" setting above
2. Run opencode (with no -m and no config "model")
   1. UI shows "OpenAI GPT-5" — correct, last-used model (from above)
   2. Press tab to switch agents → UI still shows "OpenAI GPT-5" — correct, last-used model (from above)
3. Run opencode -m anthropic/claude-sonnet-4-5
   1. UI shows "Anthropic Claude Sonnet 4.5" — correct
   2. Press tab to switch agents → UI shows "OpenAI GPT-5" — bug, last-used model instead of -m model
4. Run opencode (with no -m and no config "model")
   1. UI shows "Anthropic Claude Sonnet 4.5" — correct
   2. Press tab to switch agents → UI shows "Anthropic Claude Sonnet 4.5" — weird, now it works?
5. Run opencode -m openai/gpt-5
   1. UI shows "OpenAI GPT-5" — correct
   2. Press tab to switch agents → UI shows "Anthropic Claude Sonnet 4.5" — bug, last-used model instead of -m model
6. Run opencode (with no -m and no config "model")
   1. UI shows "OpenAI GPT-5" — correct
   2. Press tab to switch agents → UI shows "OpenAI GPT-5" — weird, now it works?

OpenCode version

1.0.18

Steps to reproduce

(above)

Screenshot and/or share link

No response

Operating System

macOS 15.5

Terminal

VS Code terminal

[github-actions]

This issue might be a duplicate of existing issues. Please check:

• Can't select openrouter models from cli or config in 1.0 #3857: Similar model configuration issues with CLI (-m flag) vs config file behavior in 1.0
• Separate model assignments no longer working after 1.0 #3706: Reports that separate model assignments per agent no longer work after 1.0, which is related to model switching behavior

Feel free to ignore if none of these address your specific case.

[jdanbrown]

Thanks! Confirmed fixed in 1.0.20.