# Pro hack: Trigger cross-doc sync with an action (hidden formula)

**URL:** <https://connect.superhuman.com/t/pro-hack-trigger-cross-doc-sync-with-an-action-hidden-formula/14518>\
**Category:** Tips and Hacks\
**Created:** [March 19, 2020, 9:40pm UTC](https://connect.superhuman.com/t/pro-hack-trigger-cross-doc-sync-with-an-action-hidden-formula/14518 "2020-03-19T21:40:50Z")\
**Posts on this page:** 1\
**Showing post:** 13

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**Author:** ![Paul\_Danyliuk](https://yyz1.discourse-cdn.com/coda1/user_avatar/connect.superhuman.com/paul_danyliuk/32/27228_2.png) [@Paul\_Danyliuk](https://connect.superhuman.com/u/Paul_Danyliuk)\
**Post date:** [April 29, 2020, 2:23pm UTC](https://connect.superhuman.com/t/pro-hack-trigger-cross-doc-sync-with-an-action-hidden-formula/14518/13 "2020-04-29T14:23:03Z")

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Let’s say Doc A is a data source and Doc B is where you have the sync table from Doc A. I see the process like this:

1. Doc B inserts a row into Doc A through a Cross-doc action
2. Doc A has an automation listening on new/updated rows in that table you just inserted a row to.
3. When automation triggers, Doc A updates that trigger cell in Doc B through a Cross-doc ModifyRow action.
4. Doc B has an automation listening on that cell change, as per the trick. This triggers the startsync/synctabletable scenario, and the table eventually updates.

So the idea is to replace who’s modifying that cell and triggering the sync. Previously it was Doc B who updated that value. Now it should be Doc A remotely into Doc B. This should work because the automation in Doc A will only fire when the added row has actually landed into the snapshot.

Regarding setting this up, I personally always prefer to set up any actions in buttons, not in the automation settings directly. I think editing buttons is easier, partially because it preserves newlines.

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