ADR 0106: the bus is NATS — native, built beside the migration, cut over after its core; issue 104 resolved

03-DESIGN/01-to-be/08-connectivity.md

@@ -10,6 +10,7 @@ code:
 updated: 2026-09-23
 decisions:
   - 02-DECISIONS/0104-a-provision-may-be-answered-by-an-adapter-to-the-predecessor.md
+  - 02-DECISIONS/0106-the-bus-is-nats.md
   - 02-DECISIONS/0105-the-mesh-adopts-the-predecessors-tunnel-in-place.md
   - 02-DECISIONS/0103-what-an-adopted-node-holds-and-what-its-guard-refuses.md
   - 02-DECISIONS/0100-a-node-in-use-is-adopted-before-it-is-converged.md
@@ -732,3 +733,14 @@ controller composes follows it, as readers of a setting. ADR 0100's non-overlap
 where a found tunnel is left running beside the mesh's; where it is adopted there is one tunnel.
 The guard admits the mesh's ports from that one interface, and the predecessor's peers arrive on
 it.
+
+## The bus is NATS
+
+*2026-09-23, [ADR 0106](../../02-DECISIONS/0106-the-bus-is-nats.md). Architecture to be written
+before code; this section names the shape only.*
+
+Every link the mesh has rides NATS subjects; durability is JetStream's; a module's account is a
+NATS account with permissions derived from `emits`/`consumes`, declared as configuration the host
+writes and the server reloads. The sdk's contract is unchanged. The adopted AMQP broker stays as
+the predecessor's compatibility broker until its last client is gone. Built in the lab beside the
+migration; cut over in one rollout after the core; the person's client is designed on it.