Struct TokenUsage 

pub struct TokenUsage {
    pub prompt_tokens: u64,
    pub completion_tokens: u64,
    pub total_tokens: u64,
    pub context_window: u64,
    pub cache_read_input_tokens: u64,
    pub cache_creation_input_tokens: u64,
}

Token usage statistics from a model response.

Fields

prompt_tokens: u64

Number of tokens in the prompt/input.

For providers with prompt caching (Anthropic), this is the non-cached prefix only — the tokens after the last cache breakpoint. The cached portion is reported separately in Self::cache_read_input_tokens / Self::cache_creation_input_tokens, so the true input total is the sum of all three. Pricing those three buckets at the same rate over- or under-counts cost; see crate::outcome::ModelProfile::usd_per_success.

completion_tokens: u64

Number of tokens in the completion/output.

total_tokens: u64

Total tokens (prompt + completion).

context_window: u64

Model’s maximum context window size.

cache_read_input_tokens: u64

Prompt-cache hit: input tokens read from a previously written cache entry. Billed at ~0.1× the base input rate. 0 when the provider has no prompt caching, caching was disabled, or nothing hit. (Anthropic usage.cache_read_input_tokens.)

cache_creation_input_tokens: u64

Prompt-cache write: input tokens written into the cache this request. Billed at ~1.25× (5-minute TTL) or ~2× (1-hour TTL) the base input rate. 0 when caching is off or nothing was written. (Anthropic usage.cache_creation_input_tokens.)

Trait Implementations

impl Clone for TokenUsage

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for TokenUsage

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

Formats the value using the given formatter.

impl Default for TokenUsage

fn default() -> Self

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for TokenUsage

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl JsonSchema for TokenUsage

fn schema_name() -> String

The name of the generated JSON Schema.

fn schema_id() -> Cow<'static, str>

Returns a string that uniquely identifies the schema produced by this type.

fn json_schema(generator: &mut SchemaGenerator) -> Schema

Generates a JSON Schema for this type.

fn is_referenceable() -> bool

Whether JSON Schemas generated for this type should be re-used where possible using the $ref keyword.

impl Serialize for TokenUsage

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

where __S: Serializer,

Serialize this value into the given Serde serializer.