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Sweep 22 Oct 2026 · 04:32Z Build v2.1.308 527 read Stable v2.1.308 Latest v2.1.308 Next v2.1.308 Feeds RSS JSON llms.txt llms-full.txt Unofficial
HomeDocsClaude Code CLI 22 Sep 2026
One change · claude-code

Track cost and usage changedagent-sdk/cost-tracking

Nearest release: v2.1.280, published 12 hours after upstream edited the page. Shown because the two are within 24 hours of each other. Nothing here says the release caused the edit.

Upstream edited this page at 22 Sep 2026 03:07 UTC, give or take a minute or two: the time comes from Anthropic’s own sitemap rather than from a commit. This site recorded the change at 28 Sep 2026 23:37 UTC.

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From line 85 where the diff opens
First seen 14 Aug 2026 this site's first read of the page
Recorded edits11to this page, all time

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8585 
8686The three result-level fields differ in what they count when the agent spawns [subagents](/docs/en/agent-sdk/subagents). Use `modelUsage`, or `model_usage` in Python, for whole-tree token accounting; the `usage` field undercounts as soon as nesting occurs.
8787 
88| Field | Subagent activity |
89| ---------------------------- | ------------------------------------------------------------------------------------------------- |
90| `usage` | Excluded. Counts only the top-level agent loop, so tokens consumed inside subagents are not added |
91| `total_cost_usd` | Included. Counts subagent requests alongside the top-level loop |
92| `modelUsage` / `model_usage` | Included. Counts subagent requests alongside the top-level loop, broken down by model |
88| Field | Subagent activity |
89| - | - |
90| `usage` | Excluded. Counts only the top-level agent loop, so tokens consumed inside subagents are not added |
91| `total_cost_usd` | Included. Counts subagent requests alongside the top-level loop |
92| `modelUsage` / `model_usage` | Included. Counts subagent requests alongside the top-level loop, broken down by model |
9393 
9494In [single message input mode](/docs/en/agent-sdk/streaming-vs-single-mode#single-message-input), when background subagents are still running at the end of the final turn, Claude Code waits for them, up to the cap described in [background tasks at exit](/docs/en/headless#background-tasks-at-exit), before emitting the result. The result's `total_cost_usd`, `duration_api_ms`, and `modelUsage`, or `model_usage` in Python, include the work done during that wait.
9595 
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