Struct Usage 

pub struct Usage {
    pub input_tokens: u64,
    pub output_tokens: u64,
    pub total_tokens: u64,
    pub cached_input_tokens: u64,
    pub cache_creation_input_tokens: u64,
    pub tool_use_prompt_tokens: u64,
    pub reasoning_tokens: u64,
}

Struct representing the token usage for a completion request. If tokens used are 0, then the provider failed to supply token usage metrics.

Fields

input_tokens: u64

The number of input (“prompt”) tokens used in a given request.

output_tokens: u64

The number of output (“completion”) tokens used in a given request.

total_tokens: u64

We store this separately as some providers may only report one number

cached_input_tokens: u64

The number of input tokens read from a provider-managed cache

cache_creation_input_tokens: u64

The number of input tokens written to a provider-managed cache

tool_use_prompt_tokens: u64

The number of tool-use prompt tokens used in a given request.

reasoning_tokens: u64

The number of tokens spent on internal reasoning / “thoughts” by reasoning-capable models (e.g. Gemini thinking, Anthropic extended thinking, OpenAI o-series).

Implementations

impl Usage

pub fn new() -> Self

Creates a new instance of Usage.

pub fn has_values(&self) -> bool

Whether any usage values are set and non-zero.

Zero-valued usage is this type’s documented sentinel for “the provider supplied no usage metrics”, so false means usage was not reported.

Trait Implementations

impl Add for Usage

type Output = Usage

The resulting type after applying the + operator.

fn add(self, other: Self) -> Self::Output

Performs the + operation.

impl AddAssign for Usage

fn add_assign(&mut self, other: Self)

Performs the += operation.

impl Clone for Usage

fn clone(&self) -> Usage

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Usage

impl Debug for Usage

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

Formats the value using the given formatter.

impl Default for Usage

fn default() -> Self

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for Usage

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Eq for Usage

impl PartialEq for Usage

fn eq(&self, other: &Usage) -> 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 Usage

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

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for Usage