• I have looked for existing issues (including closed) about this

Feature Request

We need to add a OpenRouter reasoning details support.

Motivation

Provider it does expect it to be in the same input for the next round of messages. https://openrouter.ai/docs/guides/best-practices/reasoning-tokens#preserving-reasoning-blocks

Proposal

I am thinking of either adding a generic serde json details to the Reasoning object or parsing the details.
We still don't have a good support for summary, so for now we might just support the signature.