Enum ThinkingMode 

pub enum ThinkingMode {
    Auto,
    On,
    Off,
}

Qwen3 hybrid thinking control. Qwen3 models were trained with both a “thinking” (chain-of-thought inside <think>...</think>) and a non-thinking mode. Upstream defaults thinking ON; /no_think and /think are the documented per-turn overrides in the chat template.

Scope: applies to the single-turn local Qwen3 path driven by apply_chat_template. The multi-turn messages: Vec<Message> field on GenerateRequest is consumed by remote protocol handlers (OpenAI/Anthropic/Google) which pass through user-supplied system messages verbatim; this flag is not injected there. If you need Qwen3 thinking control over a remote API, include /think or /no_think explicitly in your own system message.

Variants

Auto

Let the model decide. No explicit /think or /no_think directive is injected into the system prompt, so Qwen3’s trained default (thinking ON) applies. <think>...</think> output is stripped from the returned text.

On

Inject /think into the system prompt to explicitly request the thinking phase. Useful when callers want to force reasoning even on short prompts the model would normally answer directly.

Off

Inject /no_think into the system prompt to suppress the thinking phase for faster, more direct responses. This was the prior hard-coded behavior; callers now opt into it explicitly.

Implementations

impl ThinkingMode

pub fn directive(self) -> Option<&'static str>

Return the directive marker to append to the system prompt, or None when Auto (don’t inject anything — trust model default).

Trait Implementations

impl Clone for ThinkingMode

fn clone(&self) -> ThinkingMode

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ThinkingMode

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for ThinkingMode

fn default() -> ThinkingMode

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for ThinkingMode

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl PartialEq for ThinkingMode

fn eq(&self, other: &ThinkingMode) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Serialize for ThinkingMode

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl Copy for ThinkingMode

impl Eq for ThinkingMode

impl StructuralPartialEq for ThinkingMode