[Bug] Main agent reverted from DeepSeek to Kimi-K3 mid-task, causing unintended charges

Summary

A long-running desktop task unexpectedly reverted from DeepSeek to moonshotai/Kimi-K3 for the main agent loop. The visible interaction produced three Kimi-K3 inference calls with roughly 706k–734k input tokens each, resulting in $12.159 of unintended charges.

This is distinct from #326: these were not background title-generation or taste-learning calls. Kimi generated the main assistant response, invoked todo_write, processed its result, invoked shell_command, processed that result, and generated the final response.

Expected behavior

After selecting DeepSeek for the task, subsequent main-agent requests should continue using the selected/resolved DeepSeek model unless I explicitly change it.

The documented model-resolution behavior says an explicit in-session model selection applies to subsequent outgoing requests and that a resumed conversation adopts its saved model.

Actual behavior

At 2026-08-07 15:35:28 MYT, the user message:

Oh, then how come the Todos are still there?

started a three-turn main-agent/tool loop using moonshotai/Kimi-K3:

Local time	Main-agent action	Input tokens	Output tokens	Dashboard cost
15:35:28	Responded and invoked todo_write	706,501	568	$5.67
15:36:56	Processed tool result and invoked shell_command	733,152	313	$5.88
15:37:27	Processed verification and produced final response	733,978	348	$0.609

The last turn reported 732,928 cache-read tokens. Total unexpected Kimi cost shown by the dashboard: $12.159.

Local transcript evidence

Task/session ID:

abe_tmr6jN-UORYdoZ5NZ

The on-disk JSONL records each assistant turn's actual model and usage. The relevant records identify all three assistant turns as:

model: moonshotai/Kimi-K3

The model history in this same task was:

2026-08-06 12:19 MYT  moonshotai/Kimi-K3
2026-08-06 13:58 MYT  Qwen/Qwen3.8-Max
2026-08-06 18:32 MYT  xai/grok-4.5
2026-08-07 08:12 MYT  deepseek/deepseek-v4-flash
2026-08-07 12:08 MYT  deepseek/deepseek-v4-pro
2026-08-07 15:35 MYT  moonshotai/Kimi-K3  <-- unexpected reversion

The immediately preceding main-agent turns, through 14:36 MYT, used deepseek/deepseek-v4-pro. Earlier in the same task I had explicitly requested DeepSeek V4 Flash and the agent twice queried the model config and confirmed deepseek/deepseek-v4-flash.

After the incident, the desktop state file showed both the global selection and this task's saved model as deepseek/deepseek-v4-flash.

Checks performed

• No personal or project custom-agent files existed.
• No agent/subagent tool was invoked during the incident.
• No model: moonshotai/Kimi-K3 pin was found in Command Code agent/config files.
• The Kimi calls are present in the main task transcript, causally connected to the user's message and the returned tool results.
• The desktop process had been running continuously since 08:11 MYT; there was no app restart immediately before the 15:35 incident.
• A separate taste-1 learning call appears afterward in billing, but it is separate from these Kimi main-agent calls.

This suggests a desktop/session/backend model-state desynchronization or erroneous restoration of the task's original model.

Environment

• Command Code Desktop: 0.1.8
• Bundled command-code: 1.14.0
• OS: macOS (Apple Silicon)
• Task entrypoint: interactive desktop
• Provider: Command Code
• Context size at incident: approximately 706k–734k input tokens

Billing trace prefixes

a8bb9698...
b3b111c0...
223f5d34...

I can provide the complete local transcript or additional screenshots privately, but have not attached the full JSONL publicly because it contains private project and tool-call data.

Requested investigation

1. Determine why the main task reverted to its original Kimi-K3 model after later DeepSeek selections.
2. Confirm whether the desktop UI/task model and backend execution model can become desynchronized.
3. Add the resolved model ID to request-visible diagnostics before submission.
4. Consider a warning/confirmation when a task with a very large context changes to a materially more expensive model.