You could edit your workflow rule to add another action to it instead of creating a complete new custom action. You simply click on your workflow rule, “edit”, scroll down to “ Add another action”, then select what action you need: update a field, send an email, send a report, etc.

I have a similar issue and extending the workflow won’t work (I don’t think)

I need to have the user add a note when the workflow = True and as far as I can tell, to prompt user input for the note, I need to have a custom action to kick off. The workflow answer only pulls data from existing fields into the note.

Does anyone have a solution to that scenario?

​@ShaneDodge If I’m understanding correctly, I think what you need is to create a validation rule instead of a custom action action. Your workflow would be, if conditions a + b + c happen, then the user would receive a notification message reminding them to fill out the note.

No, I want if a + b + c happen, I want a custom action to fire with a textbox that will give the user instructions, then take that text and put it into a note.

Oh I see…. one option I can think of is to set a condition where if a + b +c, an email is sent to the project owner. That email would contain the instructions, any data you want to pull from the project, etc. Another option would be to create a notification pop-up, same thing, you can add fields to pull from the project, you can add some instructions there too..

This gave me an idea that I think will work.
In the notification body I put the following code:

Hi {CurrentUser()},
Click <a href="{GetCustomActionUrl('Opt Out Reason',GetRuntimeParameter(CurrentObject()))}">HERE</a> to add a note to this record.

Opt Out Reason is my custom action name

This gives them a pop up box with a URL link that kicks off the custom action.

Thanks again for your help!