Google Apps Script - get tasks from a project

[Jeff_Schneider]

Unfortunately, there is no way to filter for completed tasks in the Asana API. Sorry that the error message wasn’t very helpful. We hope to add more filtering in the future. Here is a post that goes into more detail about this aspect of the API:

Getting completed tasks

Hi @waghanza, Unfortunately, we don’t have the sort of filtering in our API where you can query to a subset of tasks that match an arbitrary pattern that you specify (i.e. “only the tasks where completed=true”). We also don’t have an easy way to only get the completed tasks. You can get all incomplete tasks fairly easily by specifying completed_since=now on the tasks query endpoint - which is admittedly a bit strange, but works - but its converse (get only completed tasks) doesn’t exist …