Struct Usage 

pub struct Usage {
    pub input_tokens: u32,
    pub cache_read_tokens: u32,
    pub cache_write_tokens: u32,
    pub output_tokens: u32,
    pub reasoning_tokens: u32,
    pub server_tool_calls: BTreeMap<String, u32>,
}

Canonical token usage. Axes are disjoint — billing computes cost as a sum over (axis, rate) pairs without any subtraction or clamping.

Input axes

• input_tokens: uncached new input (the portion the model has to read fresh)
• cache_read_tokens: served from prompt cache (cheaper than base input)
• cache_write_tokens: written to prompt cache this turn (often more expensive than base input — Anthropic charges ~1.25× for cache writes)

Output axes

• output_tokens: regular completion tokens, excluding reasoning
• reasoning_tokens: thinking/reasoning tokens (may have a separate rate)

Side-channel

• server_tool_calls: per-call billing for upstream-side tools like web search. Keyed by tool name ("web_search", etc.).

Fields

input_tokens: u32

cache_read_tokens: u32

cache_write_tokens: u32

output_tokens: u32

reasoning_tokens: u32

server_tool_calls: BTreeMap<String, u32>

Implementations

impl Usage

pub fn prompt_tokens(&self) -> u32

Total prompt size (cached + uncached + writes). Equivalent to OpenAI’s prompt_tokens.

pub fn completion_tokens(&self) -> u32

Total completion size including reasoning. Equivalent to OpenAI’s completion_tokens.

pub fn total_tokens(&self) -> u32

Prompt plus completion — equivalent to OpenAI’s total_tokens.

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 Default for Usage

fn default() -> Usage

Returns the “default value” for a type.

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 From<&[u8]> for Usage

fn from(raw: &[u8]) -> Self

Converts to this type from the input type.

impl From<&AnthropicUsage> for Usage

fn from(u: &AnthropicUsage) -> Self

Converts to this type from the input type.

impl From<&GeminiUsage> for Usage

fn from(u: &GeminiUsage) -> Self

Converts to this type from the input type.

impl From<&OpenAiUsage> for Usage

fn from(u: &OpenAiUsage) -> Self

Converts to this type from the input type.

impl From<&Usage> for AnthropicUsage

fn from(u: &Usage) -> Self

Converts to this type from the input type.

impl From<&Usage> for GeminiUsage

fn from(u: &Usage) -> Self

Converts to this type from the input type.

impl From<&Usage> for OpenAiUsage

fn from(u: &Usage) -> Self

Converts to this type from the input type.

impl PartialEq for Usage

fn eq(&self, other: &Usage) -> 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 Usage

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

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl Eq for Usage

impl StructuralPartialEq for Usage