Customizable Thinking tags

[AlbertoLanaro]

Description

As discussed here, it probably makes sense to make START_THINK_TAG and END_THINK_TAG customizable at model-level.

In fact, sometimes some models (e.g. Claude 4 when used via OpenRouter), even though prompted to use CoT with tags, use different tag content (such as ) that are not parsed correctly.

References

No response

[DouweM]

@AlbertoLanaro Makes sense, this should be a field on ModelProfile, so that a default can be set for different models based on model provider/name, which can also easily be overridden by the user using the profile arg to Model.

Would you be up for submitting a PR?