Struct TokenUsage 

pub struct TokenUsage {
    pub prompt_tokens: Option<u32>,
    pub completion_tokens: Option<u32>,
    pub reasoning_tokens: Option<u32>,
    pub total_tokens: Option<u32>,
}

Tokens a provider reported for one request.

Reported rather than estimated: a caller’s own token estimate decides what to send, and this says what it actually cost. Every field is optional because providers disagree on which they return, and a missing count must not read as zero.

Fields

prompt_tokens: Option<u32>

Tokens in the request, including the system prompt and tool definitions.

completion_tokens: Option<u32>

Tokens the model generated, excluding reasoning where a provider splits them out.

reasoning_tokens: Option<u32>

Reasoning tokens, where the provider reports them separately. Billed, and invisible in completion_tokens on most providers.

total_tokens: Option<u32>

The provider’s own total. Not derived from the fields above — a provider that reports only this one is common, and a total that disagrees with the parts is the provider’s answer, not ours to correct.

Implementations

impl TokenUsage

pub fn is_empty(&self) -> bool

Whether the provider reported anything at all. A response carrying no counts is Some(TokenUsage::default()) nowhere — it is None.

Trait Implementations

impl Clone for TokenUsage

fn clone(&self) -> TokenUsage

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for TokenUsage

impl Debug for TokenUsage

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

Formats the value using the given formatter.

impl Default for TokenUsage

fn default() -> TokenUsage

Returns the “default value” for a type.

impl Display for TokenUsage

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

Formats the value using the given formatter.

impl Eq for TokenUsage

impl PartialEq for TokenUsage

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for TokenUsage