List or filter all activity types

To list only a specific activity type (e.g., only `Call` or `LeadStatusChange`), use the other resources listed separately. When querying activities for a single lead (using the `lead_id` parameter), you can ask for multiple activity types using `_type__in`. When listing [Custom Activities](/resources/custom-activities/), `_type` and `_type__in` can include Custom Activity Type ids (e.g. `actitype_1h5m6uHM9BZOpwVhyRJb4Y`) to filter by a specific custom activity type or `Custom` to list custom activities of any type. The following filtering parameters can only be used for listing activities on a single lead (using the `lead_id` parameter): `user_id`, `user_id__in`, `contact_id`, `contact_id__in`, `_type`, `_type__in`. All activities have two sortable datetime fields: `date_created` and `activity_at`. `date_created` denotes when an activity was created or synced into Close and `activity_at` denotes when that activity actually occurred. For example, on outgoing Email activities, `date_created` is equal to when the email was first created in Close, and `activity_at` is equal to when the email was actually sent. For Meeting activities, `activity_at` is equal to the scheduled time of the meeting. On custom activities, users are able to update the `activity_at` field at any time. Sorting by `-activity_at` can only be used when listing activities on a single lead using the `lead_id` parameter. In addition, you can only use the date-based filters of the field you're currently sorting on. This means that if you want to use `activity_at__lt` and `activity_at__gt` as filters, you need to include `_order_by=-activity_at` in your request. `thread_emails` parameter: - (Default) when this parameter is not present, `Email` objects will be returned for each email message. - A value of `true` will return `EmailThread` objects representing email conversations. Stripped-down version of `Email` objects will also be returned. - A value of `only` will return `EmailThread` objects representing email conversations. `Email` objects will not be returned.