Struct LLMMetrics 

pub struct LLMMetrics {
    pub prompt_tokens: u32,
    pub completion_tokens: u32,
    pub total_tokens: u32,
    pub time_to_first_token_ms: f64,
    pub tokens_per_second: f64,
    pub latency_ms: f64,
    pub cost_usd: Option<f64>,
    pub model_name: String,
    pub timestamp: DateTime<Utc>,
    pub request_id: Option<String>,
    pub tags: HashMap<String, String>,
}

LLM call metrics

Fields

prompt_tokens: u32

Number of tokens in the prompt

completion_tokens: u32

Number of tokens in the completion

total_tokens: u32

Total tokens (prompt + completion)

time_to_first_token_ms: f64

Time to first token in milliseconds

tokens_per_second: f64

Tokens generated per second

latency_ms: f64

Total latency in milliseconds

cost_usd: Option<f64>

Estimated cost in USD (if known)

model_name: String

Model name (e.g., “gpt-4”, “claude-3-opus”)

timestamp: DateTime<Utc>

Timestamp of the call

request_id: Option<String>

Optional request ID

tags: HashMap<String, String>

Optional tags

Implementations

impl LLMMetrics

pub fn new(model_name: &str) -> Self

Create new LLM metrics with model name

pub fn with_tokens(self, prompt: u32, completion: u32) -> Self

Set token counts

pub fn with_latency(self, latency_ms: f64) -> Self

Set latency

pub fn with_ttft(self, ttft_ms: f64) -> Self

Set time to first token

pub fn with_cost(self, cost_usd: f64) -> Self

Set cost

pub fn with_request_id(self, id: &str) -> Self

Set request ID

pub fn with_tag(self, key: &str, value: &str) -> Self

Add a tag

pub fn estimate_cost(&self) -> f64

Calculate cost based on model pricing (approximate)

N-07 (Meyer DbC): Prices are approximate and may be stale. Order matters: more specific patterns (e.g., “gpt-4-turbo”) must precede generic ones (“gpt-4”) to avoid mis-categorization. Unknown models warn and use a conservative default.

Trait Implementations

impl Clone for LLMMetrics

fn clone(&self) -> LLMMetrics

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for LLMMetrics

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for LLMMetrics

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for LLMMetrics

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

where __S: Serializer,

Serialize this value into the given Serde serializer.