"Too many checklists" (403) error


One of my users is reporting a 403 error with “Too many checklists” in the body, when the Power Up is trying to fetch the board data via call to api.trello.com/1/board/{idBoard}/cards.

Can you help me figure out what causes this error, and more importantly how can I fix it for him?

Anyone? I noticed that when I make a call with ‘fields’ parameter including all important fields except ‘checkItemStates’, the error disappears. Earlier I have been calling simply ‘?fields=all’.

I noticed that the ‘checkItemStates’ is null regardless if I have a checklist with a mix of completed/open items on the given card or no checklists at all. It seems strange to me to throw an error when due to using a field that is always ‘null’.

Are you having a bug there? Could you investigate and potentially update your API, so calling this API, with ‘?fields=all’ does not pose a risk of throwing this sort of errors in the future?

This can happen when a board has a very large number of checklists. The current limit is 5000, although that can change in the future. Given that this is an unusual situation, I don’t think we’d consider this a bug. If you need to work with such boards, it may be best to exclude that field. If you let us know more about your use case, we’re happy to help brainstorm workarounds as well.

Thank you for your reply and shedding some light on the matter, dbernal.

At the moment I believe I can get around without that field being present. However, I am considering adding, in the future, functionality that would require information about the checklists to be present and that might become an issue.
I think it would be a good strategy for you to inform our users that they are crossing the limit, when they are creating new checklists. Else, they have valid reason to expect, that their checklists can be fully processed by both you and custom Power Ups.

I am good for now and I will reach out if the new functionality will prove to cause issues, so we can brainstorm a solution, as you suggested.

Once again… Thank you for your help!