Struct ContextUsage 

pub struct ContextUsage {
    pub usage_ratio: Option<f64>,
    pub context_limit: Option<u32>,
    pub input_tokens: u32,
    pub output_tokens: u32,
    pub cache_read_tokens: Option<u32>,
    pub cache_creation_tokens: Option<u32>,
    pub reasoning_tokens: Option<u32>,
    pub total_input_tokens: u64,
    pub total_output_tokens: u64,
    pub total_cache_read_tokens: u64,
    pub total_cache_creation_tokens: u64,
    pub total_reasoning_tokens: u64,
}

Context/token usage reported after an LLM call.

Per-call fields (input_tokens, output_tokens, cache_read_tokens, cache_creation_tokens, reasoning_tokens) come from the most recent API response. The total_* fields are cumulative across the agent’s lifetime. The optional fields are None when the provider doesn’t expose that dimension; this is semantically distinct from Some(0).

Fields

usage_ratio: Option<f64>

Current usage ratio (0.0 - 1.0), if context window is known.

context_limit: Option<u32>

Maximum context limit, if known.

input_tokens: u32

Input tokens on the most recent API call (the current context size).

output_tokens: u32

Output tokens on the most recent API call.

cache_read_tokens: Option<u32>

Prompt tokens served from cache on the most recent API call.

cache_creation_tokens: Option<u32>

Prompt tokens written to cache on the most recent API call.

reasoning_tokens: Option<u32>

Reasoning tokens spent on the most recent API call.

total_input_tokens: u64

Cumulative input tokens since the agent started.

total_output_tokens: u64

Cumulative output tokens since the agent started.

total_cache_read_tokens: u64

Cumulative cache-read tokens since the agent started.

total_cache_creation_tokens: u64

Cumulative cache-creation tokens since the agent started.

total_reasoning_tokens: u64

Cumulative reasoning tokens since the agent started.

Implementations

impl ContextUsage

pub fn total_tokens(&self) -> u64

Sum of cumulative input + output tokens.

Trait Implementations

impl Clone for ContextUsage

fn clone(&self) -> ContextUsage

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ContextUsage

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

Formats the value using the given formatter.

impl Default for ContextUsage

fn default() -> ContextUsage

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for ContextUsage

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl JsonSchema for ContextUsage

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

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 inline_schema() -> bool

Whether JSON Schemas generated for this type should be included directly in parent schemas, rather than being re-used where possible using the $ref keyword.

impl PartialEq for ContextUsage

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

Equality operator ==.

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

Inequality operator !=.

impl Serialize for ContextUsage

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.

impl StructuralPartialEq for ContextUsage