OptionaladdOptionalenableOptionalpreserveOptionalreasoningTemplate-level reasoning depth (Qwen3.8: xhigh|medium|low — the template RAISES on other values, so callers must map OpenAI levels first and only set this for templates that read it; see ChatTemplate.readsReasoningEffort).
Optionaltools
Keep think blocks from historical assistant turns in the rendered prompt (Qwen3.8
preserve_thinking, template default true — better prompt-cache reuse and agent-trace continuity). Only passed when the template reads it.