Just a few things I've picked up this evening:
https://groups.io/static/api#get-topics consistently getting BAD_REQUEST with this one despite a valid group_id set (https://api.groups.io/v1/gettopics?group_id=1405) that the calling user has access to (as an owner). Originally thought it might be because of 0 topics/messages, but even after adding a couple of messages to the group I'm still getting the same response (repro'd with Postman to skip the Java client).
(Generally) example schemas don't always tally with response attribute listings, mostly just a case of some missing fields. I'm using the schemas to generate POJOs which means I'm sometimes missing a couple of attributes.
(Generally) some required tags missing orange label formatting
(Suggestion) displaying requirements for calls in a consistent way - permissions, plan levels, and required params.
https://groups.io/static/api#get-member is missing mandatory group_id param in example request
https://groups.io/static/api#the-user-object missing comma after time_pref value (invalid JSON)
https://groups.io/static/api#get-topics typo in is_closed attribute name (response attributes)
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