watch-limits

---

name: watch-limits description: Use when you want a recurring monitor of your Claude subscription usage limits — weekly/5h burn rate, whether you'll blow the weekly cap before it resets, which idle session to compact, and ctx-wire token savings. Triggers: "am I going to hit my limit", "watch my usage", "burn rate", "which session to compact".

watch-limits — recurring usage-limit watcher

Overview

Installs an activity-aware burn-rate projector and schedules a recurring status watcher. The watcher reports, every ~30 min: weekly + 5h limit burn, a compaction pick, and ctx-wire savings. Do not hand-roll the projection or the schedule — this skill is the canonical setup; reinventing it produces false alarms and duplicate jobs.

Prerequisites

• cctop on PATH (cctop --json works) — per-session live stats.
• ~/.claude/cctop/usage.json present and fresh (<1h). Written by a status-line tap (cctop --capture-usage); if missing, tell the user to set up that tap first — the watcher has no weekly data without it.
• ctx-wire (optional) for section 4. Skip that section if absent.

Setup flow

1. Install the projector:

   mkdir -p ~/.claude/cctop
   cp "${CLAUDE_PLUGIN_ROOT}/skills/watch-limits/burn-proj.py" ~/.claude/cctop/burn-proj.py
   

2. Guard against duplicates. List existing scheduled jobs first. If a 7,37 * * * * watcher reading usage.json already exists, STOP — offer to replace it (delete the old one), never add a second. Duplicate watchers double the noise and can clobber each other.
3. Schedule the watcher. Use the prompt in watcher-prompt.md (bundled beside this file). Schedule it recurring at 7,37 * * * * (off the :00/:30 marks on purpose). If the host has no cron tool, run it as a /loop instead.
4. Seed the ctx-wire delta baseline so the first tick shows a real interval:

   printf '{"saved_tokens":%s,"ts":%s}\n' \
     "$(ctx-wire gain --json | jq .saved_tokens)" "$(date +%s)" \
     > ~/.claude/cctop/ctxwire-last.json 2>/dev/null || true
   

The projection (why not straight-line)

The 7-day window is FIXED, not rolling: it hard-resets at seven_day.resets_at; window start = resets_at − 604800. burn-proj.py prints two numbers:

• naive = used / elapsed_fraction — worst case, assumes you burn every day at your average-so-far rate. Self-heals as elapsed grows.
• profile_aware = discounts the hours you predictably don't burn — a sleep window (02:00–09:00 ×0.05) and the weekend (Sat ×0.5, Sun ×0.1). The real forecast — a hot evening or weekday start does NOT mean you'll blow the cap if the hours ahead are predictably light (asleep or resting).

Lead with profile_aware; flag only when it exceeds 100%. Reporting a naive evening/mid-week spike as "WILL BLOW" is the false alarm this skill exists to prevent — the projection should bend down as the clock nears your sleep window. Tune the sleep hours and weekend multipliers in burn-proj.py's mult() to your own cadence (default active window 09:00–02:00).

Caveats

• Scheduled jobs are session-only on most hosts (die when the agent exits, auto-expire in ~7 days). Re-run this skill after a restart. durable:true is often ignored — verify rather than assume.
• Cloud schedules can't see local cctop/ctx-wire/usage.json, so this watcher only works in a session with the binaries present.

Common mistakes

Mistake	Fix
Redesigning the burn math inline	Use burn-proj.py — sleep/weekend discounting is the point
Scheduling a 2nd watcher	Check existing jobs first; replace, don't duplicate
Reporting naive % as the verdict	Lead with profile_aware; naive is the ceiling
Sorting sessions on contextTokens raw	Treat null as 0
Compacting a busy session	Only idle/waiting are safe targets