Struct SessionStats 

pub struct SessionStats {
    pub turns: u64,
    pub input_tokens: u64,
    pub output_tokens: u64,
    pub cache_read_tokens: u64,
    pub cache_write_tokens: u64,
    pub tools: Vec<(String, u64)>,
    pub last_input_tokens: Option<u64>,
}

Aggregate view of a conversation for /usage: how many turns reported usage, the summed token counts, and which tools ran.

Pure data — no timing, no cost (there is no timestamp in AgentMessage). Derive order is fixed so tests can compare by value.

Fields

turns: u64

Assistant messages that carried Some(usage).

input_tokens: u64

output_tokens: u64

cache_read_tokens: u64

Cache counts absent on a call are treated as 0.

cache_write_tokens: u64

tools: Vec<(String, u64)>

Tool name → call count, one entry per distinct name, sorted by count descending, ties broken by name ascending. Empty when no tool has been called.

last_input_tokens: Option<u64>

Provider-reported input tokens of the most recent Assistant message with Some(usage): how full the context was on the last request. None until a turn reports usage.

Implementations

impl SessionStats

pub fn summary(&self) -> String

The one-line summary both front-ends print: plain text — no colors, no layout, no context; front-ends add chrome.

Contract:

• turns == 0 ⇒ "(no usage reported)".
• otherwise ⇒ "usage: N turns, X in, Y out[, C cache read][, W cache write][, tools: …]" where the cache fields are omitted when 0, the tools: segment is omitted when no tool ran, and the tool names are capped at TOOL_LIST_CAP, the remainder folded into "+K more".
• The trailing context U/L readout is intentionally NOT here: its limit comes from the front-end (REPL model_limit, TUI status.context_limit), so each wraps/appends it.

Trait Implementations

impl Clone for SessionStats

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for SessionStats

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

Formats the value using the given formatter.

impl Default for SessionStats

fn default() -> Self

Returns the “default value” for a type.

impl Eq for SessionStats

impl PartialEq for SessionStats

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for SessionStats