Cron Runnables

The Cron node metadata owns the schedule; the source owns the work.
A Cron file is executable Nenu, not a cron declaration block.
Cron source can be authored and validated, but App Marché does not execute Cron nodes yet.

Schedule Outside, Logic Inside

A Cron node stores its schedule in App Marché metadata. Its .cron.nenu source contains only executable Nenu statements. There is no cron keyword or source wrapper.

Cron metadata	Cron source
Schedule	Reads and queries
Node identity	Conditions and loops
Execution trigger	Writes, logs, cache, or failures

Scheduled Room Summary

This scheduled job rebuilds a cached total from durable open expenses. It needs no invented clock or request input: the schedule triggers it, and the entities provide the data.

crons/rebuild-room-summary.cron.nenu

1need expenses = Expense[]({2  status == ExpenseStatus.Open3}) | limit(200)45number total = 067loop expenses as expense {8  total = total + expense.amount9}1011cache.set("room-open-expense-total", total)12log("Finished room expense summary rebuild")

Designing Repeatable Jobs

Query a bounded batch with deterministic filters and ordering when order matters.
Make each run safe when no matching records exist.
Use a transaction when several writes must commit together.
Log a non-empty literal event name and, when useful, one payload expression.
Let invalid required reads or explicit throw end the run as failures.

Common Mistakes

Wrong	Correct
`cron "0 0 * * *" { ... }`	Set the schedule in Cron metadata.
`runnable Cleanup { ... }`	Write statements directly.
Use `request` without a contract	Use only values supplied by the active runnable context.
Call standalone `now()`	Use the built-in namespace form `time.now()`.

Continue Learning

Backend Effects Use logging, cache, and errors in scheduled work.Queries Bound and order the records processed by a job.