Cleaning up completed ToDo tasks

I started playing with Microsoft To Do automation a little bit more than ~~I should~~ usual. However, I quite quickly came up to API limitations. The maximum number of items to pull is 999. That includes completed tasks. I decided I need to clean up old tasks. To make sure I do not have this issue anymore, I'd need to schedule a Power Automate task.

Requirements

• Power Automate license (included in M365 license - I have Business Premium)
• Personal Microsoft To Do

Note

Commercial To Do should work in similar manner but I personally store tasks on personal account

Workflow

Here are the steps of my workflow:

1. List all to-do lists
2. For each list list to do's
3. Filter array to get only completed and older than a month (or any predefined number of days)
4. Delete each task

Here's the view of the steps I perform for each list:

Part of the flow that runs for each list

Steps

To get only completed items we use:

@equals(item()?['status'],'completed')

To get only items that are older than 30 days, we can use:

@less(item()?['completedDateTime']?['dateTime'],addDays(utcNow(),-30))

Note

For simplicity we do not consider time zones. We also splitted the filtering to two steps for easier troubleshooting

Complete flow

You can download the flow from GitHub: ArchiveAllButLastServiceHealthNotification.zip

Note on run duration

When I run the flow on 2000+ items, it took hours to complete. I gave up and deleted the items manually, letting the flow to cover the ongoing items:

Duration of flows run on bigger number of items