List a task's history: its action log, oldest first, in pages of at most 100 actions chained by cursors.after. Every action names its source: the user, API key, agent or platform process that performed it. The log holds the create, every reassign, snooze, unsnooze and set-notifications, the closing complete, skip, cancel or delete with its outcome, the documents added to or removed from the task, on a conflict task each further clarification case that joined it (add-case), and on a task a carrier's price change opened each further price change the tour took over (carrier-price-change). Validator credentials in the stored form are masked.