Can't add a task with formula field even though the value is empty - 400: Cannot directly create or update the value for a formula custom field.

I am using to add a new task into Asana. The Project in question has some custom fields, one of which is a formula. But I am not adding any data into that, its empty. See attached for custom field values passed.

Yet we receive the following error which I believe is returned by Asana?

##### InvalidConfigurationError
400: Cannot directly create or update the value for a formula custom field.

So I am a bit stuck! Anyone know how to get around this when you are not actually adding a value to a custom formula field?

The field in question is Profit, which is calculated form the Amity Quote minus Supplier Cost. Even if I pass a 0 in to those two it fails. If I pass a 0 into the Profit formula field it fails.


Hi @Laurence_Cope,

You have to leave the field out completely when submitting the update; you can’t even submit it with 0/blank/null data.

Ok thanks. So its my responsibility to work around it then. I read that you cant add or update formula fields even with a value. So its amazingly surprising we have to take care of omitting rather than just Asana not do anything with it.

I use and using the built in Asana integration the custom fields are there in the module, I cant delete it I dont think. It dynamically fetches my custom fields from Asana when I choose the project to add a task into.

So really not sure what to do at the moment if I cant remove it as its built in. I wonder who made the Asana integration. If its Make, I can raise a support ticket with them informing them they cant submit formula fields.

In fact, in when you examine the data sent, the field is reported as a #number.

That’s correct - that’s not Make doing that, it’s recorded in the Asana API as a number field. You have to check the is_formula_field property of a custom field to determine if it’s a formula or just a regular number field.

The Make integration is from Make so, yes, I would recommend reaching out to them.

Ooh coincidentally there is a new version Asana module in thats just released. It has far more integrations, but the module is not preparing the empty custom fields automatically and so now the Asana task updates. It actually offers an option to choose Yes or No for “Generate Workspace Custom Fields”. Well thats a coincidence and is great! So all working now. Thanks

Excellent news, @Laurence_Cope!