Struct TokenBudget 

pub struct TokenBudget {
    pub max_tokens: usize,
    pub max_cost_usd: Option<f64>,
    pub input_tokens_used: usize,
    pub output_tokens_used: usize,
    pub cost_usd: f64,
    pub input_cost_per_1k: f64,
    pub output_cost_per_1k: f64,
}

Token budget tracking for cost control

Tracks input/output token usage and enforces limits per PSP-4 –max-cost.

Fields

max_tokens: usize

Maximum total tokens allowed (input + output)

max_cost_usd: Option<f64>

Maximum cost in dollars (optional)

input_tokens_used: usize

Input tokens used

output_tokens_used: usize

Output tokens used

cost_usd: f64

Estimated cost so far (in USD)

input_cost_per_1k: f64

Cost per 1K input tokens (varies by model)

output_cost_per_1k: f64

Cost per 1K output tokens (varies by model)

Implementations

impl TokenBudget

pub fn new(max_tokens: usize, max_cost_usd: Option<f64>) -> TokenBudget

Create a new token budget with limits

pub fn record_usage(&mut self, input_tokens: usize, output_tokens: usize)

Record token usage from an LLM call

pub fn total_tokens_used(&self) -> usize

Get total tokens used

pub fn remaining_tokens(&self) -> usize

Get remaining token budget

pub fn is_exhausted(&self) -> bool

Check if budget is exhausted

pub fn cost_exceeded(&self) -> bool

Check if cost limit exceeded

pub fn should_stop(&self) -> bool

Check if we should stop due to budget

pub fn usage_percent(&self) -> f32

Get budget usage percentage

pub fn set_pricing(&mut self, input_per_1k: f64, output_per_1k: f64)

Set model-specific pricing

pub fn summary(&self) -> String

Get formatted summary

Trait Implementations

impl Clone for TokenBudget

fn clone(&self) -> TokenBudget

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for TokenBudget

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

Formats the value using the given formatter.

impl Default for TokenBudget

fn default() -> TokenBudget

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for TokenBudget

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for TokenBudget

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.