Struct ThinkingConfig 

pub struct ThinkingConfig {
    pub thinking_budget: Option<i32>,
    pub include_thoughts: Option<bool>,
    pub thinking_level: Option<ThinkingLevel>,
}

Available on crate features gemini and models only.

Configuration for thinking (Gemini 2.5 and 3 series)

Fields

thinking_budget: Option<i32>

The thinking budget (number of thinking tokens)

This is the Gemini 2.5 budget-based thinking control.

• Set to 0 to disable thinking
• Set to -1 for dynamic thinking (model decides)
• Set to a positive number for a specific token budget

Model-specific ranges:

• 2.5 Pro: 128 to 32768 (cannot disable thinking)
• 2.5 Flash: 0 to 24576
• 2.5 Flash Lite: 512 to 24576

include_thoughts: Option<bool>

Whether to include thought summaries in the response

When enabled, the response will include synthesized versions of the model’s raw thoughts, providing insights into the reasoning process.

thinking_level: Option<ThinkingLevel>

Native thinking level for Gemini 3 models.

When set, the model uses level-based reasoning instead of a token budget. Do not combine with thinking_budget — use one or the other.

Implementations

impl ThinkingConfig

pub fn validate(&self) -> Result<(), String>

Validate the thinking configuration.

Returns an error if both thinking_budget and thinking_level are set, since they are mutually exclusive controls (budget for Gemini 2.5, level for Gemini 3).

pub fn new() -> ThinkingConfig

Create a new thinking config with default settings

pub fn with_thinking_budget(self, budget: i32) -> ThinkingConfig

Set the thinking budget (Gemini 2.5 budget-based control)

pub fn with_dynamic_thinking(self) -> ThinkingConfig

Enable dynamic thinking (model decides the budget)

pub fn with_thoughts_included(self, include: bool) -> ThinkingConfig

Include thought summaries in the response

pub fn with_thinking_level(self, level: ThinkingLevel) -> ThinkingConfig

Set the thinking level (Gemini 3 native level-based control).

This is the preferred control for Gemini 3 models. Do not combine with with_thinking_budget — use one or the other.

pub fn dynamic_thinking() -> ThinkingConfig

Create a thinking config that enables dynamic thinking with thoughts included

Trait Implementations

impl Clone for ThinkingConfig

fn clone(&self) -> ThinkingConfig

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ThinkingConfig

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

Formats the value using the given formatter.

impl Default for ThinkingConfig

fn default() -> ThinkingConfig

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for ThinkingConfig

fn deserialize<__D>( __deserializer: __D, ) -> Result<ThinkingConfig, <__D as Deserializer<'de>>::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for ThinkingConfig

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

where __S: Serializer,

Serialize this value into the given Serde serializer.