Scheduled tasks: run a script, a prompt, or both #24947

Request

Let a scheduled task run a script (a shell command in the project folder) as well as, or instead of, a prompt:

• Prompt only: what exists today.
• Script only: the command runs on the trigger and its output is posted to the task's thread. No agent turn.
• Both: the script runs first and its output is passed into the prompt. If the script exits without output (or with a chosen exit code), the agent turn is skipped.

Triggers stay the same (interval, time of day, webhook).

Why

Many recurring jobs are fixed steps that need no judgment: check a queue, read machine load, start the next item. Today each run of those jobs wakes an agent just to call one tool, which costs model usage on every tick. An OS scheduler (launchd, systemd) avoids that but ties the job to one machine, and it isn't visible in T3.

The "both" mode also helps judgment jobs (sweeps, triage): a cheap script checks whether anything changed, and the agent runs only when it did.

A script can already change its own next run time by calling the existing schedule-update tool, so that doesn't need to be part of this.

Related

• [Bug]: schedule_task can't set model or reasoning effort, and silently ignores modelSelection #16833 (schedule_task can't set the model, so even a one-tool-call tick runs on the thread's model)
• [Bug]: /schedule or CronCreate jobs only live inside the Claude process not in a T3code thread #13439 (scheduled jobs living outside T3 threads)