Flows
Services don’t only sit side by side — they hand work to each other. Flows is the plumbing for that exchange: the message queues and event streams that carry data from one service to the next, the scheduled jobs that run on a clock, and the integrations that move data deliberately from one zone to another. It’s plumbing for events, not packets — the physical wire between hosts is Mesh; this is what travels along it.
Direction and boundary still matter. Source code, for one, flows one way only — from the open community forge into the secret-bearing production forge, never back. Each integration is shaped on purpose: what it carries, which way it runs, and which zones it may bridge. The messaging and automation packages are in Software; the rules that gate a cross-zone flow are in Guard.