The list endpoint returns all of the cohorts in a given project. The JSON formatted return contains the cohort name, id, count, description, creation date, and visibility for every cohort in the project.

If you're trying to get a list of users in a cohort, you can use the /engage endpoint with the filter_by_cohort parameter. The Query API has a rate limit of 60 queries per hour and a maximum of 5 concurrent queries.