Struct Usage 

pub struct Usage {
    pub prompt_tokens: Option<u32>,
    pub completion_tokens: Option<u32>,
    pub total_tokens: Option<u32>,
    pub prompt_tokens_details: Option<PromptTokensDetails>,
}

Token usage statistics. Notes:

• total_tokens ≈ prompt_tokens + completion_tokens.
• Some providers omit usage in streaming chunks; expect it mainly in the final response.
• prompt_tokens_details.cached_tokens often indicates KV-cache hits or reused tokens.

Fields

prompt_tokens: Option<u32>

Number of tokens in the prompt.

completion_tokens: Option<u32>

Number of tokens in the completion.

total_tokens: Option<u32>

Total tokens for this request (prompt + completion).

prompt_tokens_details: Option<PromptTokensDetails>

Details for prompt tokens (e.g., cached tokens count)

Implementations

impl Usage

pub fn prompt_tokens(&self) -> Option<u32>

Number of prompt tokens.

pub fn completion_tokens(&self) -> Option<u32>

Number of completion tokens.

pub fn total_tokens(&self) -> Option<u32>

Total tokens for this request.

pub fn prompt_tokens_details(&self) -> Option<&PromptTokensDetails>

Breakdown of prompt-token accounting.

Trait Implementations

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 Debug for Usage

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

Formats the value using the given formatter.

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 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 Validate for Usage

fn validate(&self) -> Result<(), ValidationErrors>

impl<'v_a> ValidateArgs<'v_a> for Usage

type Args = ()

fn validate_with_args(&self, args: Self::Args) -> Result<(), ValidationErrors>