# Tip: Automatic Broadcast Expiry

**URL:** <https://cylc.discourse.group/t/tip-automatic-broadcast-expiry/1256>\
**Category:** Tips\
**Created:** [October 10, 2025, 12:28pm UTC](https://cylc.discourse.group/t/tip-automatic-broadcast-expiry/1256 "2025-10-10T12:28:39Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![oliver.sanders](https://yyz2.discourse-cdn.com/free1/user_avatar/cylc.discourse.group/oliver.sanders/32/110_2.png) [@oliver.sanders](https://cylc.discourse.group/u/oliver.sanders)\
**Post date:** [October 10, 2025, 12:28pm UTC](https://cylc.discourse.group/t/tip-automatic-broadcast-expiry/1256/1 "2025-10-10T12:28:39Z")

</div>

Broadcasts automatically expire (i.e, are deleted) once they are no longer required by upcoming tasks.

This means that if you try to re-run a task from the previous cycle, its broadcasts will likely have been expired. In Cylc 8.6.0, we have pushed back the broadcast expiry limit to make it easier to re-run tasks from the previous cycle. For more information, see [the user guide](https://cylc.github.io/cylc-doc/stable/html/user-guide/running-workflows/cylc-broadcast.html#user-guide-broadcast-expiry).

Another consequence of broadcast expiry is that broadcasts made to historical cycles (behind the broadcast expiry point) will expire instantly. The `cylc trigger --on-resume` option was added to allow us to broadcast to a cycle before triggering the task:

- Pause the workflow.
- Trigger the task using the `--on-resume` option (the task will not run until the workflow is resumed).
- Issue the broadcast.
- Resume the workflow (the task will now run).

At Cylc 8.6.0, automatic broadcast expiry is suspended while the workflow is paused which simplifies this process:

- Pause the workflow.
- Issue the broadcast.
- Trigger the task (no special option required).
- Resume the workflow.

Note the order of the broadcast and trigger operations has swapped to the logical order.

The `--on-resume` option has been removed.