Struct SubagentUsageRollup 

pub struct SubagentUsageRollup {
    pub subagent_tokens: u64,
    pub agent_count: u32,
    pub tool_uses: u64,
    pub duration_ms: u64,
    /* private fields */
}

Session-level subagent token rollup — the <subagent_tokens> / <agent_count> line items the Claude CLI renders in its terminal <usage> block.

The stream-json protocol does not carry this rollup on the result frame’s usage (confirmed against the CLI binary — the terminal renderer computes it from Task tool results). Consumers that need it must accumulate it the same way: feed every session message through observe and read the totals at any point.

A Task result observed twice under the same agentId (e.g. a replayed frame on resume) is counted once. Results with no agentId are counted every time they are observed.

Example

use claude_codes::{ClaudeOutput, SubagentUsageRollup};

let mut rollup = SubagentUsageRollup::default();
let json = r#"{"type":"user","message":{"role":"user","content":[]},"session_id":"7fbc568e-2bd6-45aa-b217-a1cf80004ba1","tool_use_result":{"status":"completed","agentId":"ab52f22445470d454","totalDurationMs":1853,"totalTokens":10201,"totalToolUseCount":0}}"#;
let output: ClaudeOutput = serde_json::from_str(json).unwrap();
rollup.observe(&output);
assert_eq!(rollup.subagent_tokens, 10201);
assert_eq!(rollup.agent_count, 1);

Fields

subagent_tokens: u64

Total tokens consumed by subagents — sum of SubagentResult::total_tokens over every observed Task result.

agent_count: u32

Number of subagent runs observed (<agent_count>).

tool_uses: u64

Total subagent tool invocations — sum of total_tool_use_count.

duration_ms: u64

Total subagent wall-clock milliseconds — sum of total_duration_ms.

Implementations

impl SubagentUsageRollup

pub fn observe(&mut self, output: &ClaudeOutput) -> bool

Accumulate output into the rollup if it is a Task tool result.

Returns true when the message contributed to the totals. Non-user messages, user messages without a tool_use_result, results from other tools, and duplicate agentIds are all ignored.

pub fn observe_user(&mut self, user: &UserMessage) -> bool

Accumulate a user message’s Task tool result, if it carries one.

Every SubagentResult field is optional, so any JSON object in tool_use_result parses as one (e.g. a Bash or ToolSearch result). Only results carrying an agentId or a totalTokens line item are treated as genuine Task results.

Trait Implementations

impl Clone for SubagentUsageRollup

fn clone(&self) -> SubagentUsageRollup

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for SubagentUsageRollup

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

Formats the value using the given formatter.

impl Default for SubagentUsageRollup

fn default() -> SubagentUsageRollup

Returns the “default value” for a type.

impl Eq for SubagentUsageRollup

impl PartialEq for SubagentUsageRollup

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for SubagentUsageRollup