/loop-from-task — turn a TaskList item into a self-terminating loop

Why this exists

Composing the existing primitives:

• TaskList is the durable cross-fire state per CLAUDE.md
• /loop schedules cron-driven fires
• The natural pattern "keep working on task X until it's done" needs glue between them — that's this skill

A loop created via /loop-from-task carries a self-terminating prompt: each fire checks the task's status, continues work if in_progress or pending, and /loop-stops itself once completed.

Argument parsing

/loop-from-task <task-id> <interval>
/loop-from-task <task-id> <interval> notes: "<additional context>"

• <task-id> — TaskList ID (e.g. 3). Required.
• <interval> — same syntax as /loop (5m, 1h, 30s, 2d).
• notes: — optional additional context appended to the generated prompt (e.g. "stop at 5pm", "PR is blocked on review").

If either positional arg is missing: show TaskList, ask which to loop on and at what cadence.

Steps

1. Verify the task exists. Call TaskList. If <task-id> isn't present, error out with the current list.
2. Verify the task isn't already completed. If status == completed, tell user "task #N is already done — nothing to loop on" and stop.
3. Verify no existing loop already wraps this task. Check CronList + ~/.claude/.paused-loops.json for any prompt containing loop-from-task: task-<id> (we tag the generated prompt). If found, tell user, don't duplicate.

4. Convert interval to cron (same table as /loop):

   Pattern	Cron expression
   Nm (≤59)	*/N * * * *
   Nm (≥60)	0 */H * * * (H = N/60)
   Nh	0 */N * * *
   Nd	0 0 */N * *
   Ns	round up to 1m

5. Generate the loop prompt. Template:

   /loop-from-task: task-<id>
   
   SELF-CHECK FIRST: call TaskList. Find task #<id> ("<subject>").
   
   If task status == completed:
     → /loop-stop this loop (cron id <self-id-or-placeholder>). Then post a one-line "task #<id> done; loop terminated" and exit.
   
   If task status == in_progress:
     → Continue working on it. Don't restart. Don't fragment progress.
     
   If task status == pending:
     → TaskUpdate status=in_progress, then work on it.
   
   If task is blocked (other tasks blockedBy points to it):
     → Note the blockers in this fire's output; do NOT mark in_progress; wait.
   
   <NOTES BLOCK IF PROVIDED>
   
   Canary: if you canceled or stopped this loop, you should NOT be seeing this message.

   The cron-self-id will be substituted in step 6 after CronCreate returns the actual ID (use <self> as placeholder, then patch the prompt with the real ID via CronDelete + CronCreate cycle — OR accept that the placeholder remains and the agent uses /loops to find its own ID at fire time).

   Simpler alternative: don't try to embed the loop's own ID; the agent at fire time uses /loops or CronList to discover the cron carrying the matching /loop-from-task: task-<id> tag and stops THAT specific cron. This is what the skill recommends.

6. CronCreate with the cron expression + prompt + recurring=true.
7. Append history event:

   {"event":"created","at":"...Z","id":"<new-cron-id>","cron":"...","tag":"loop-from-task","task_id":"<task-id>","label":"task-<id>: <subject first 40 chars>"}

8. TaskUpdate the task: add metadata loop_cron_id: <new-cron-id> so future TaskList views show "this task is being looped on by cron X."
9. Don't execute the prompt now. The first cron fire (in ≤N minutes) is when work begins. This differs from raw /loop which fires immediately — for task-driven loops, we want one clean work-cycle window, not double-firing.
10. Confirm to user:

    Loop started: cron <id> fires every <interval>, working on task #<task-id> "<subject>" until completed. Use /loop-stop <id> to cancel manually, /loops to monitor, or just mark the task completed and the loop self-terminates on next fire.

Don't

• Don't auto-mark the task in_progress at create time. Let the first cron fire decide based on task state.
• Don't refuse if the task is pending — that's the common case.
• Don't try to be smart about multi-task loops. One task per loop; user creates multiple /loop-from-task invocations if they want parallel work.
• Don't ignore the notes: field — it's how the user injects per-task constraints the generic prompt can't know.

See also

• /loop — the lower-level cron primitive
• /loop-stop — manual cancellation (loop-from-task loops also self-terminate, but manual stop still works)
• /loops — find the cron ID currently looping on task #N