Cachebeat

# cachebeat — prompt-cache keepalive heartbeat

## What you do when invoked

`/cachebeat [minutes] [hours]` arms the heartbeat; `/cachebeat stop` turns it off. **There is nothing
for you to run.** The heartbeat is the Stop hook in this skill's frontmatter: Claude Code registered it
when this skill loaded, and when this turn ends the hook reads these same arguments from the transcript.

- `minutes`: idle threshold — how long the session may sit silent before a beat. Default **50**,
  clamped to **5–55** (past ~55 the 1-hour cache TTL can lapse before a beat lands).
- `hours`: auto-stop deadline. Default **8**, clamped to 1–24 — the abandoned-session guard: every beat
  costs a small cached-price request, so a forgotten heartbeat must end itself.
- `stop` (or `off`): disarm.

Reply in **ONE line** and call no tools — arming: the idle threshold, the auto-stop time, and that
`/cachebeat stop` ends it sooner; stopping: that it is off. Nothing more.

If the user asks in plain words to start, change or stop the heartbeat, invoke this skill (Skill tool)
with the matching arguments: the hook only reads `/cachebeat` invocations.

## When the heartbeat wakes you

A system reminder starting with `[cachebeat]` (on some Claude Code versions: "Stop hook blocking error …"
followed by the same text) comes from the hook. It is not the user, and it is not an error.

- **"idle heartbeat …"** — reply with exactly `.` and nothing else: no tools, no summary, no status. The