Type

Bug

Problem / Value

When using DeepSeek V3.1 Terminus via OpenRouter, reasoning/thinking appears to be enabled by default and there’s no way to turn it off. This leads to worse answers for some tasks and increases token usage. Users expect to run the non‑reasoning variant but cannot opt out.

Context

• Affects users who select DeepSeek V3.1 Terminus under the OpenRouter provider.
• Observed in Settings and during chats after selecting the model.
• The rest of the product already supports configuring reasoning behavior; this specific model/provider path doesn’t let users disable it.

Reproduction

1. In Settings, choose OpenRouter as the provider and select DeepSeek V3.1 Terminus.
2. Start a chat or review the model controls.
3. There is no OFF option to disable reasoning/thinking; responses behave as if reasoning is on.

Expected result

• Clear ability to disable reasoning for this model on OpenRouter.
• When disabled, the model should not return or charge for reasoning tokens, and it should behave like the non‑reasoning variant.

Actual result

• Reasoning appears active by default for DeepSeek V3.1 Terminus on OpenRouter.
• No OFF control is available; users can’t opt out of reasoning behavior.

Constraints/Preferences

• Fix the behavior so reasoning can be turned off for this specific model/provider combination.
• Default to reasoning OFF for this model to avoid unexpected quality/cost impacts.