2026-09-05 10:27:11 +00:00
1 changed files with 27 additions and 9 deletions
@@ -232,17 +232,35 @@ join, and it lags. Today a board queries the mesh's own database directly — th
 it works, and this rule makes it a migration rather than a preference. The reason to pay it is
 [`how-we-build`](../../00-META/how-we-build.md) §4's already-measured cost, not elegance.

-### What it does not answer
+### Checked against the real consumers

-**The mesh's own registry is read by many things.** Under this rule they cannot read its tables,
-so they consume its events or call its tools. That is achievable and it is a real change from
-how the mesh works today, where reading the registry directly is ordinary — and it is the same
-change [ADR 0037](../../02-DECISIONS/0037-the-host-applies-it-does-not-decide.md) already forces
-on the host for unrelated reasons.
+The rule's survival turned on whether every reader of the mesh's own registry could be served
+some other way. **Eighteen consumers open a direct connection to it.** Four groups, and only one
+of them is work.

-Whether *every* consumer of the registry can be served by events and an interface is not
-established here. It is the one thing that could make this rule unworkable, and it should be
-checked against real consumers before the rule is recorded as a decision.
+| Group | What happens under the rule |
+|---|---|
+| **The owner and its machinery** — the mesh module, the SDK, the environment and configuration synchronisers, secrets | Nothing. It owns the database. |
+| **Node appliers** — the overlay, the shell daemon, the resolver | **Already resolved.** [ADR 0037](../../02-DECISIONS/0037-the-host-applies-it-does-not-decide.md) stops the host querying the mesh database, decided for tier reasons with nothing to do with this. |
+| **Foreign tenants** — the work engine (10 tables), the knowledge base (2), pipeline logs (1) | They need **their own database**. They are not reading the registry; they are storing their own data in it. |
+| **Genuine cross-context reads** — the work engine reads `nodes`; two others read a handful | The only ones needing an interface or events. |
+
+**Thirteen foreign tables live in the mesh's registry database**, belonging to three separate
+contexts. That is [`how-we-build`](../../00-META/how-we-build.md) §4's shared schema, counted.
+
+**So the question was the wrong shape.** The bulk of the problem is not readers needing a new
+route to data — it is **tenants needing to move out**. Tasks, agents and teams have nothing to do
+with nodes and modules; they are co-located by history. Give that context its own database and
+its dependency on the registry shrinks to a single table.
+
+What remains is a handful of genuine cross-context reads, small enough to enumerate rather than
+estimate. **The rule holds.**
+
+### What it still does not answer
+
+Whether those remaining reads want an **interface** or **events**. A consumer asking *which
+nodes exist* at the moment it needs to know is a request; one that must react *when a node
+appears* is a subscription. Some will want both, and nothing here says which.

 ## A migration belongs to the consumer and runs on the provider