Struct ClaudeSession 

pub struct ClaudeSession {

    pub pid: u32,
    pub session_id: String,
    pub cwd: String,
    pub project_name: String,
    pub started_at: u64,
    pub elapsed: Duration,
    pub tty: String,
    pub status: SessionStatus,
    pub cpu_percent: f32,
    pub cpu_history: Vec<f32>,
    pub mem_mb: f64,
    pub own_input_tokens: u64,
    pub own_output_tokens: u64,
    pub own_cache_read_tokens: u64,
    pub own_cache_write_tokens: u64,
    pub own_cache_write_1h_tokens: u64,
    pub last_usage_msg_id: Option<String>,
    pub subagent_input_tokens: u64,
    pub subagent_output_tokens: u64,
    pub subagent_cache_read_tokens: u64,
    pub subagent_cache_write_tokens: u64,
    pub subagent_cache_write_1h_tokens: u64,
    pub total_input_tokens: u64,
    pub total_output_tokens: u64,
    pub model: String,
    pub command_args: String,
    pub session_name: String,
    pub jsonl_path: Option<PathBuf>,
    pub jsonl_offset: u64,
    pub last_message_ts: u64,
    pub cache_read_tokens: u64,
    pub cache_write_tokens: u64,
    pub cost_usd: f64,
    pub context_tokens: u64,
    pub context_max: u64,
    pub prev_cost_usd: f64,
    pub burn_rate_per_hr: f64,
    pub burn_rate_ewma: f64,
    pub burn_samples: VecDeque<f64>,
    pub subagent_count: usize,
    pub active_subagent_count: usize,
    pub active_subagent_jsonl_paths: Vec<PathBuf>,
    pub subagent_rollups: HashMap<PathBuf, SubagentRollup>,
    pub activity_history: Vec<u8>,
    pub files_modified: HashMap<String, u32>,
    pub tool_usage: HashMap<String, ToolStats>,
    pub worktree_id: Option<String>,
    pub telemetry_status: TelemetryStatus,
    pub usage_metrics_available: bool,
    pub cost_estimate_unverified: bool,
    pub model_profile_source: String,
    pub last_msg_type: String,
    pub last_stop_reason: String,
    pub is_waiting_for_task: bool,
    pub pending_tool_name: Option<String>,
    pub pending_tool_input: Option<String>,
    pub pending_file_path: Option<String>,
    pub has_file_conflict: bool,
    pub last_tool_error: bool,
    pub last_error_message: Option<String>,
    pub recent_errors: Vec<ErrorEntry>,
    pub total_tokens_at_edit_count: u64,
    pub edit_event_count: u32,
    pub baseline_tokens_per_edit: Option<f64>,
    pub error_counts_per_window: Vec<u32>,
    pub current_window_errors: u32,
    pub window_tick_counter: u32,
    pub baseline_error_rate: Option<f64>,
    pub file_reads_since_edit: HashMap<String, u32>,
    pub total_error_count: u32,
    pub decay_score: u32,
    pub worker_origin: Option<String>,
}

Fields

pid: u32

session_id: String

cwd: String

project_name: String

started_at: u64

elapsed: Duration

tty: String

status: SessionStatus

cpu_percent: f32

cpu_history: Vec<f32>

mem_mb: f64

own_input_tokens: u64

own_output_tokens: u64

own_cache_read_tokens: u64

own_cache_write_tokens: u64

own_cache_write_1h_tokens: u64

The subset of own_cache_write_tokens written with a 1-hour TTL, which bills at 2x base input rather than 1.25x.

last_usage_msg_id: Option<String>

The message id whose usage was counted most recently.

Claude Code writes one JSONL line per content block of an assistant turn — thinking, text, tool_use — and repeats the turn’s whole usage on each. Counting every line charged the same tokens two or three times over. Duplicate lines are always adjacent (verified across 4814 turns in 25 transcripts), so remembering one id is enough, and it has to live on the session because parsing is incremental and a turn’s lines can straddle two reads.

subagent_input_tokens: u64

subagent_output_tokens: u64

subagent_cache_read_tokens: u64

subagent_cache_write_tokens: u64

subagent_cache_write_1h_tokens: u64

1-hour-TTL subset of subagent_cache_write_tokens.

total_input_tokens: u64

total_output_tokens: u64

model: String

command_args: String

session_name: String

jsonl_path: Option<PathBuf>

jsonl_offset: u64

last_message_ts: u64

cache_read_tokens: u64

cache_write_tokens: u64

cost_usd: f64

context_tokens: u64

context_max: u64

prev_cost_usd: f64

burn_rate_per_hr: f64

burn_rate_ewma: f64

EWMA-smoothed burn rate ($/hr) used for budget forecasting. Damps the tick-to-tick flicker of burn_rate_per_hr. See forecast (#370).

burn_samples: VecDeque<f64>

Recent instantaneous burn samples ($/hr), capped at BURN_SAMPLE_CAP, for the p10/p90 ETA band. In-memory only (rebuilt at runtime).

subagent_count: usize

active_subagent_count: usize

active_subagent_jsonl_paths: Vec<PathBuf>

subagent_rollups: HashMap<PathBuf, SubagentRollup>

activity_history: Vec<u8>

files_modified: HashMap<String, u32>

tool_usage: HashMap<String, ToolStats>

worktree_id: Option<String>

telemetry_status: TelemetryStatus

usage_metrics_available: bool

cost_estimate_unverified: bool

model_profile_source: String

last_msg_type: String

Persisted across ticks so status inference works when no new JSONL arrives.

last_stop_reason: String

is_waiting_for_task: bool

pending_tool_name: Option<String>

Pending tool call details for rule-based auto-actions.

pending_tool_input: Option<String>

pending_file_path: Option<String>

has_file_conflict: bool

last_tool_error: bool

last_error_message: Option<String>

recent_errors: Vec<ErrorEntry>

total_tokens_at_edit_count: u64

Cumulative tokens at each Edit/Write event (for efficiency trending).

edit_event_count: u32

Number of Edit/Write events (for averaging tokens-per-edit).

baseline_tokens_per_edit: Option<f64>

Baseline tokens-per-edit, frozen after first 5 edits.

error_counts_per_window: Vec<u32>

Error count ring buffer: one entry per window (~10s each).

current_window_errors: u32

Accumulator for current error window.

window_tick_counter: u32

Ticks since last window flush.

baseline_error_rate: Option<f64>

Baseline error rate (errors per window), frozen after 3 windows.

file_reads_since_edit: HashMap<String, u32>

File reads since last edit: path -> read count. Reset when file is edited.

total_error_count: u32

All-time error count.

decay_score: u32

Cached composite decay score (0-100), recomputed each tick.

worker_origin: Option<String>

If set, this session is from a remote worker (not local). Terminal actions (approve, kill, etc.) are disabled for remote sessions.

Implementations

impl ClaudeSession

pub fn from_raw(raw: RawSession) -> Self

pub fn record_activity(&mut self)

Record current status into the activity sparkline ring buffer. Max 15 entries (one per tick, at 2s default = 30s of history).

pub fn record_burn_sample(&mut self, interval_secs: f64)

Fold the current instantaneous burn_rate_per_hr into the EWMA and the rolling sample window. Call once per refresh after burn is recomputed. interval_secs is the refresh cadence (shapes the EWMA half-life).

pub fn budget_eta(&self, budget_usd: f64) -> EtaBand

Forecast time-to-budget for this session given a per-session cap, as a p10/p90 interval. None when the session isn’t burning or has no cap.

pub fn format_sparkline(&self) -> String

Render the sparkline as unicode block characters.

pub fn display_name(&self) -> &str

pub fn is_remote(&self) -> bool

Whether this session is from a remote worker (not local).

pub fn from_remote_json(worker_id: &str, json: &Value) -> Option<Self>

Build a ClaudeSession from remote JSON (as received via heartbeat/HTTP).

pub fn format_subagent_summary(&self) -> String

pub fn subagent_breakdown(&self) -> Vec<SubagentBreakdown>

pub fn format_elapsed(&self) -> String

pub fn format_tokens(&self) -> String

pub fn format_mem(&self) -> String

pub fn format_cost(&self) -> String

pub fn context_percent(&self) -> f64

pub fn format_context(&self) -> String

Format context as “450k/1M 45%” or a visual bar

pub fn format_context_bar(&self, width: usize) -> String

Visual bar for context usage: ████░░ 62%

pub fn to_json_value(&self) -> Value

Produce a JSON-serializable value for –json export.

pub fn format_burn_rate(&self) -> String

pub fn telemetry_label(&self) -> &'static str

pub fn has_usage_metrics(&self) -> bool

Trait Implementations

impl Clone for ClaudeSession

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 ClaudeSession

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

Formats the value using the given formatter.