The activity feed of one contact: its history of what the contact has done recently and which campaigns and emails were sent to it, as events recorded over time. Email opens are not activities: this feed shows sends (Log) and clicks (LinkData) but cannot say whether the contact opened an email. Send contact with the contact id. The request first refreshes that contact's feed from the underlying tables, so recent events appear, then returns the entries. A request without contact reads activities across the whole account; on a large account that scans millions of rows and can run for many minutes, so always scope the read to one contact. Each entry says what happened through reference type and reference_action, and names the underlying record with reference_id and reference (its API type and id). What the types mean: Log, a campaign email was sent to the contact (include reference.log.campaign to see which campaign); LinkData, the contact clicked a tracked link in a campaign email (include reference.link for the link); MppLinkData, a campaign link was fetched by a mail privacy proxy rather than by the contact; Forward, the contact forwarded a campaign; Reply, the contact replied to a campaign; Update, the contact updated their details through a campaign's update link; SubscriberEmail, a one-to-one email was sent to the contact from the platform; SubscriberList with referenceaction subscribe or unsubscribe, the contact joined or left a list; SubscriberSeries with start or complete, the contact entered or completed an automation; SeriesBlock with goal, the contact reached an automation goal; Note, a note was added to the contact; SubscriberLog with merge, another contact was merged into this one; TrackingLog, a site-tracking or event-tracking hit, with the event name (orpagevisit for a page visit) in reference_action; SmsLog, SmsReply and SmsUnsub, an SMS sent, a reply and an opt-out; DealActivity and DealTask, CRM deal activity and tasks; SubscriberConversion, a conversion; EcomOrderActivity, an e-commerce order; HilosFlow and HilosConversation, WhatsApp; Enrichment, a data enrichment run; OmniChannelLinkData, a click on a link in an SMS message; FbAudienceContactLog, the contact was added to or removed from a Facebook custom audience; SubscriberRestoreActivity, the contact was archived (removed) or restored. To keep one kind of event, pass type with one or more API type names separated by commas, for example type=log,link-data; to see only events after a moment, pass after. Results are paged: limit defaults to 20 and is capped at 100, page with offset, and meta.total is the number of matching entries. Always pass orders[tstamp]=desc (newest first) or asc: without it the entries come back grouped by kind, not by time.