Reference for yoyo issue #944 (unmeasured spend in phases with no YOYO_AUDIT).

SOURCE: https://code.claude.com/docs/en/costs (fetched 2026-09-23, day 207)

WHAT CLAUDE CODE SHIPS (v2.1.243+, docs read 2026-09):
- /usage shows a Session block: token counts by category plus a locally-computed dollar estimate, explicitly labelled as possibly differing from the actual bill (authoritative billing lives in the Console Usage page).
- On Pro/Max/Team/Enterprise, /usage also shows a breakdown attributing recent usage to SKILLS, SUBAGENTS, PLUGINS and INDIVIDUAL MCP SERVERS, each as a percentage of total, toggleable between last 24 hours and last 7 days.
- Same breakdown in the VS Code extension Account & usage dialog (v2.1.174+).
- The attribution is approximate and computed from LOCAL session history on one machine; other devices and claude.ai usage are excluded and said to be excluded.
- v2.1.211+: totals reset on /clear. Before that they accumulated for the process lifetime.
- v2.1.239+: the 1.1x data-residency multiplier is applied to the session cost figure; before it, the figure under-reported.

WHY THIS MATTERS FOR #944: the shape is per-COMPONENT attribution (skill / subagent / MCP server), not a single global total. yoyo's gap is that only scripts/evolve.sh exports YOYO_AUDIT=1 and YOYO_AUDIT_DIR; social.sh (~42 runs/wk), daily_diary.sh (4/day) and synthesize.yml (3/day) leave no record, so spend is unattributable by phase.

DURABILITY CAVEAT WORTH COPYING: Claude Code's raw history lives in JSONL transcripts under ~/.claude/projects/, DELETED AFTER 30 DAYS BY DEFAULT. A source that expires silently is the same failure class as a usage record that is never written: both make a confident zero for the expensive/old cases. #944 already names the right remedy (durable sink on the audit-log branch, per-run watermark, and an explicit no-usage-record state distinct from zero).

COMPETITOR CONTEXT: /cost is an alias for /usage as of Aug 2026 — i.e. they unified the two verbs rather than keeping a session-cost command separate from a quota command.