--- summary: memsearch's SessionStart "Recent Memory" injection size is hardcoded in its hook script — no config knob controls it, and the documented TOML surface doesn't cover it. tags: - type/reference - tool/memsearch scope: global type: reference source: cc-os docs/plans/b3-memsearch-injection-review.md date: 2026-07-08 last_updated: 2026-07-08 --- # memsearch SessionStart injection is hardcoded (no cap knob) Verified on memsearch v0.4.6 and the v0.4.11 plugin cache (2026-07-08). - The SessionStart `# Recent Memory` injection is produced by `hooks/session-start.sh`, which hardcodes `head -2` daily memory files × `head -40` heading/bullet lines each. - **No user-facing config knob controls this.** The documented TOML surface (the `memory-config` skill: summarize / project_review / user_profile / memory_to_skill / prompts) does not touch the injection size — don't waste time looking for a cap there. - Measured cost across 61 real sessions (cc-os, 7 days): min ~6.0 KB / median ~11.7 KB / max ~15.4 KB per session (~1.5k–3.9k tokens), injected every SessionStart. ## Levers (in order of durability) 1. Upstream fix: a memsearch config option for injection size (doesn't exist yet; would be the only durable cap). 2. Reduce bullet density at the source via the Stop-hook summarizer prompts/config — fewer, denser bullets in the daily files shrink what `head -40` captures. 3. Unsupported stopgap: hand-edit the cached hook's `head -2`/`head -40` constants (~75% reduction) — **any plugin cache refresh silently reverts it**. Related: [[cc-os-hub]]