Struct TokenUsage 

pub struct TokenUsage {
    pub prompt_tokens: u32,
    pub completion_tokens: u32,
    pub total_tokens: u32,
}

Token usage statistics for an LLM request.

Tracks how many tokens were consumed by the prompt and completion, useful for cost estimation and monitoring context window usage.

Cost Estimation

Most providers charge per token. Multiply token counts by the provider’s per-token rate to estimate costs:

use multi_llm::TokenUsage;

let usage = TokenUsage {
    prompt_tokens: 1000,
    completion_tokens: 500,
    total_tokens: 1500,
};

// Example: OpenAI GPT-4 pricing (illustrative)
let prompt_cost = usage.prompt_tokens as f64 * 0.00003;
let completion_cost = usage.completion_tokens as f64 * 0.00006;
let total_cost = prompt_cost + completion_cost;

Fields

prompt_tokens: u32

Number of tokens in the prompt/input.

Includes system messages, conversation history, and the current query.

completion_tokens: u32

Number of tokens in the completion/output.

The generated response from the model.

total_tokens: u32

Total tokens used (prompt + completion).

Should equal prompt_tokens + completion_tokens.

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 Debug for TokenUsage

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

Formats the value using the given formatter.

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 From<OpenAIUsage> for TokenUsage

fn from(usage: OpenAIUsage) -> Self

Converts to this type from the input type.

impl PartialEq for TokenUsage

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

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.

impl StructuralPartialEq for TokenUsage