Struct UsageIteration 

pub struct UsageIteration {
    pub input_tokens: u32,
    pub output_tokens: u32,
    pub cache_read_input_tokens: Option<u32>,
    pub cache_creation_input_tokens: Option<u32>,
    pub cache_creation: Option<CacheCreationDetails>,
    pub kind: Option<String>,
}

Usage for a single API call (“iteration”) within a turn’s tool-use loop.

Carried in UsageInfo::iterations. The cache fields are optional on the wire: some frames carry only input_tokens + output_tokens (observed with type: "turn"), while others carry the full cache breakdown (observed with type: "message" in captured subagent sessions). The CLI computes its context estimate from input_tokens + output_tokens of the last iteration.

Fields

input_tokens: u32

output_tokens: u32

cache_read_input_tokens: Option<u32>

Cache-read input tokens for this iteration, when carried.

cache_creation_input_tokens: Option<u32>

Cache-write input tokens for this iteration, when carried.

cache_creation: Option<CacheCreationDetails>

Cache-write breakdown by TTL, when carried.

kind: Option<String>

Iteration kind; "turn" and "message" observed on the wire.

Trait Implementations

impl Clone for UsageIteration

fn clone(&self) -> UsageIteration

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for UsageIteration

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for UsageIteration

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for UsageIteration

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

where __S: Serializer,

Serialize this value into the given Serde serializer.