# Session-start ledger latency — 40s startup check cut to 1.1s

outcome: every Claude session start/resume/compaction recovery no longer stalls ~40 seconds in the `agent-session-ledger` SessionStart hook.
status: DONE
source request: owner 2026-08-15 — "what else can we optimize, except of hooks, to reduce load on my machine?" (continuation of the hook-optimization campaign; found by the sh-fastpath lane's SessionStart audit).
acceptance criteria: installed `~/.claude/hooks/agent-session-ledger.mjs` completes in ~1s on a real transcript payload; classify semantics unchanged; regression test pins the behavior.

## Root cause

`classify()` in `modules/workstation/claude/lib/agent-session-reader.mjs` ran
`git --no-optional-locks status --porcelain` once per non-finished ledger entry.
The ledger held 11,806 entries, 986 of them non-finished — but those 986 entries
span only 11 distinct working directories. 986 serial git-status calls at ~70ms
each ≈ 40-70s, at every session start, fleet-wide.

## Fix

Per-run promise cache keyed by cwd: one git status per distinct cwd per classify
run (986 calls → 11). Landed `8a2df1fbf` (branch commit `3283b3bc7`); test
`modules/workstation/claude/tests/agent-session-classify-dirty.test.mjs` asserts
one poll per cwd. Same landing fixed origin/main's broken collector typecheck
(`deploy-status.test.ts` fetch casts, TS2352) that was blocking every land.

## Receipt

2026-08-15: measured installed entrypoint before/after on the same real payload:
39,731ms → 1,103-1,413ms (~30×). Live `~/.claude/lib/agent-session-reader.mjs`
byte-identical to origin/main copy. Existing reap test green. Deployed via ship.sh
land; worktree removed. Next executable action: none — done. Follow-on candidates
(pids-guard watch-loop CPU, node-textfile monitor cadence, quietcontext-over-HTTP
shared MCP daemon) tracked in chat briefing awaiting owner pick.