loopify — Claude Code skill: scheduled agent loops

---
name: loopify
description: When you want to set up an agent loop, cron-scheduled task, or recurring workflow that runs autonomously. Judgment layer on top of Claude Code's ScheduleWakeup, CronCreate, and /loop — or, on other hosts, cron/GitHub Actions plus a headless agent CLI. Picks dynamic pacing, fixed cron, or a one-shot loop; designs idempotent loop bodies; sets bail-out conditions so loops don't run forever. Examples — weekly review pulse, daily brief, hourly metric monitor, periodic vault compile, upstream-check for an adapted skill. Triggers on "/loopify," "set up a loop," "schedule this task," "run this daily," "run this weekly," "cron this," "make this recurring," "automate this on a schedule," "keep this running until X." Part of the -ify trifecta (skillify / toolify / loopify). NOT for authoring a new skill — that's skillify. NOT for adding a tool/integration — that's toolify.
metadata:
  version: 0.2.0
---

# /loopify — Set up an agent loop

Wizard for going from *"this task should run periodically"* to a working loop with the right pacing, idempotency, and bail-out. Reference (Claude Code): `ScheduleWakeup` (dynamic pacing), `CronCreate` (fixed schedule), and the built-in `/loop` (dynamic self-paced re-entry). Other hosts: see "On hosts other than Claude Code" in Step 4.

## Step 0 — Confirm what you're looping

Ask if not obvious from context: *"What task should this loop do each iteration?"*

Then get the essentials:

| Question | Why it matters |
|---|---|
| **How often?** | Determines cron vs dynamic vs one-shot |
| **When to stop?** | Bail-out condition — loops must have one |
| **What's the loop body doing?** | Determines idempotency requirements |
| **Where does output go?** | File / notification / commit / nothing |
| **What's the failure mode if it runs twice?** | Idempotency validation |

## Step 1 — Pick the pattern

Three primary patterns. Route by the answer to "how often":

### Pattern A — Cron (fixed schedule)

**Use when**: task runs at predictable intervals — daily at 8am, weekly on Fridays, hourly on the hour.

Tool: `CronCreate` — schedules a recurring task with a cron expression.

```
CronCreate({
  schedule: "0 8 * * *",           // daily at 8am local
  prompt: "<loop body prompt>",
  timezone: "America/Los_Angeles"
})
```

Common cron patterns:
- `0 8 * * *` — daily at 8am
- `0 9 * * 1` — Mondays at 9am
- `0 9 * * 5` — Fridays at 9am
- `0 */2 * * *` — every 2 hours
- `*/15 * * * *` — every 15 minutes

**Trade-offs:**
- ✅ Predictable, human-readable, easy to reason about
- ✅ Best for time-of-day-dependent tasks (morning brief, EOD summary)
- ❌ Runs at the scheduled time even if the last run isn't done — need idempotent body
- ❌ No self-pacing — over-schedules if the task duration varies wildly

### Pattern B — Dynamic pacing (self-scheduled)

**Use when**: task should react to state, not the clock. Monitor-until-condition-met patterns. Waiting on an external event.

Tool: `ScheduleWakeup` — the current run schedules its own next wake-up.

```
ScheduleWakeup({
  delaySeconds: 270,               // stay in cache window (< 5min)
  reason: "checking build status; sleeping under 5min to stay cache-warm",
  prompt: "<same task, re-entered>"
})
```

**Critical delay rules** (from `ScheduleWakeup` docs — internalized in the wizard):

| Delay range | Use for | Cache impact |
|---|---|---|
| **60s–270s** | Active work — polling build, waiting for state that's about to change | Stays in 5-min prompt cache — fast + cheap |
| **300s** ❌ | **DON'T USE THIS** | Worst of both worlds — pay cache miss without amortizing |
| **300s–3600s** | Waiting on something that takes minutes to change | Pay cache miss but justified |
| **1200s–1800s** (20–30 min) | Idle ticks with no specific signal | Default for autonomous loops |

Never pick 300s literally — either drop to 270 (cache stays warm) or commit to 1200+ (cache miss buys longer wait).

**Trade-offs:**
- ✅ Adaptive — sleeps longer when idle, shorter when active
- ✅ Cache-optimal when tuned right
- ❌ Requires the loop body to know when to schedule next (extra logic)
- ❌ Harder to reason about when it'll run

### Pattern C — One-shot loop (until-condition)

**Use when**: task runs until a condition is met, then stops. No recurrence after that.

Tool: `/loop` (built-in) with an exit condition in the prompt itself.

```
/loop
Check if the deploy is healthy. If yes → stop. If no → wait 5 min and check again.
Max 10 iterations. If still failing after 10, alert and stop.
```

**Trade-offs:**
- ✅ Simplest for check-until-condition
- ✅ Bounded — always eventually terminates
- ❌ Not for indefinite recurrence — that's Pattern A or B

## Step 2 — Design the loop body for idempotency

Idempotent = running the loop twice produces the same result as running it once. **Non-negotiable for cron and dynamic patterns** because they'll fire while the previous iteration is still running or partially complete.

Idempotency patterns:

- **Use "already done" markers**: e.g., commit a state file `<vault>/.loopify/<name>-last-run.txt` with the timestamp of last successful run. Loop body checks the timestamp before doing work.
- **Use dedupe keys**: if the loop writes to a DB or file, key by content-hash or timestamp so re-runs are no-ops.
- **Use transactions**: DB writes in the loop body should be atomic — either all commit or all roll back.
- **Query before mutate**: check current state before applying the change. If already applied, skip.

Show the user the loop body draft, highlighting the idempotency check. If none exists, add one.

## Step 3 — Bail-out condition

Every loop needs one. Options:

| Bail-out | When to use |
|---|---|
| **Max iterations** (e.g., stop after 100 runs) | Cron loops — prevents runaway |
| **State-based** (e.g., stop when metric X drops below Y) | Monitoring loops |
| **Time-based** (e.g., stop after 24 hours) | Bounded monitoring |
| **Error-based** (e.g., stop on 3 consecutive failures) | All loops — catches degradation |

If the loop is truly indefinite (e.g., a weekly cron with no end), still add a manual bail-out via `CronDelete`. Document it in the SKILL/loop notes so the user knows how to stop it.

## Step 4 — Set the schedule

Based on the pattern from Step 1:

**Cron (Pattern A):**
```
CronCreate({
  schedule: "<expression>",
  timezone: "<tz>",
  prompt: "<loop body>",
})
```
Report the `cron_id` returned so the user can `CronDelete` later.

**Dynamic (Pattern B):**
Wrap the loop body prompt so it ends with a `ScheduleWakeup` call:
```
<do the work>
Then: ScheduleWakeup({delaySeconds: <tuned per Step 1>, prompt: "<same body>", reason: "<why this cadence>"})
```

**One-shot (Pattern C):**
Just run `/loop <prompt with exit condition>`.

### On hosts other than Claude Code

`CronCreate`, `ScheduleWakeup`, and `/loop` are Claude Code features. Everything else in this skill (pattern choice, idempotency, bail-out, verification) applies to any agent. On other hosts, the scheduler lives outside the agent and calls a non-interactive agent run:

| Scheduler | When to use |
|---|---|
| **The host's own scheduled tasks**, if it has them | First choice. Check the host's docs |
| **System cron / launchd / systemd timer** | Machine is always on; loop needs local files |
| **GitHub Actions `schedule:`** | Loop works on a repo (vault compile, upstream check); survives a closed laptop |

The job runs a headless agent command with the loop body as the prompt, e.g. `claude -p "<body>"`, `codex exec "<body>"`, or `cursor-agent -p "<body>"`. Use whatever non-interactive mode your agent's CLI has.

- Dynamic pacing (Pattern B) has no direct equivalent. Use a fixed schedule whose body exits early when there's nothing to do.
- One-shot (Pattern C) becomes a shell `while` loop around the headless command, with the bail-out check in the loop condition.
- Headless runs can't ask for approval, so give the job the narrowest permissions that work, and have it write output to a file or notification rather than waiting on a prompt.

## Step 5 — Verify the first run

Wait for the first iteration (or trigger it manually via `/loop` with the same prompt for a dry-run). Confirm:

- Output landed where expected
- Idempotency check works (run twice — second should be a no-op)
- Bail-out condition would fire correctly if triggered
- Log/notification appears if configured

## Step 6 — Report + follow-ups

Report:
- Pattern picked (A/B/C) + why
- Cron ID or wakeup pattern registered
- Bail-out condition set
- Idempotency mechanism in place
- How to stop the loop (`CronDelete <cron_id>` or "just don't call the wakeup" for dynamic)

Offer:
- *"Save this loop configuration as a skill via `skillify from-chat`?"*
- *"Want to also register a `weekly-review` or `daily-startup` loop while we're here?"*
- *"Should the loop write to `second-brain` outputs when it runs?"*

## Common loop recipes

Templates for frequent loop types (fill in as they're used):

- `references/daily-brief.md` — morning routine loop (calendar + priorities + overnight)
- `references/weekly-review.md` — Friday portfolio pulse
- `references/upstream-check.md` — periodic check for changes to an adapted skill's upstream
- `references/vault-compile.md` — periodic raw/ → wiki/ compilation
- `references/metric-monitor.md` — poll a metric until it crosses a threshold, then alert

## Composes with

- **`skillify`** — sibling in `-ify` trifecta. Use `skillify` to author a new SKILL.md — use `loopify` when the goal is a scheduled task, not a skill.
- **`toolify`** — sibling. Use `toolify` for adding an integration — use `loopify` when the goal is running something on top of an already-integrated tool on a schedule.
- **`second-brain`** — many loops write to the vault (raw/ or outputs/). The vault auto-commit pattern applies.
- **`pm`** — daily-brief and weekly-review loops often read from pm before generating output.

## Notes on quality

- **Never pick 300s for `delaySeconds`.** Worst of both worlds. Drop to 270 or commit to 1200+.
- **Every loop needs a bail-out.** Even indefinite ones need a documented manual stop.
- **Idempotency is non-negotiable for cron + dynamic.** Assume the loop will fire twice while a previous iteration is running.
- **Prefer dynamic pacing over over-frequent cron.** Cron every 15 min wastes tokens if the work isn't ready; dynamic pacing scales down when idle.
- **Document the cron_id.** Otherwise the loop is orphaned and hard to stop.
- **Log every iteration briefly** — even a single line ("2026-06-30 08:00 daily-brief: ran, 3 items") makes debugging drift trivial.
- **Loops that touch external APIs need rate-limit respect.** If the vendor has a 100/day limit, don't schedule 500/day.
- **Bounded > unbounded when uncertain.** If unsure whether to run for a week or a month, start with a week — extend after seeing it work.