The manifest already uses serves for a provision's facts, so a module's
tools take their own key. Declaring them is itself new — until now a
module's tools existed only in a runtime environment variable.
Storage is not a property of a subject — a stream is a separate object that
covers one — so the question is always how many streams, not which topics
are durable.
Three facts decide it, two of them verified rather than assumed: NATS
refuses overlapping streams instead of merging them, so a shared stream
plus a per-module one is not available at all; a filter cannot express an
exception; and a stream per module turns one cross-module consumer into one
per module. So one stream, with per-subject caps for the fairness that
matters. Per-module age is genuinely unavailable, and a module that needs
it declares a seat.
Design 29 said no module requires the bus. The catalogue disagrees: 49 of
72 modules take a broker credential and 23 do not, so an ambient connection
mints an account for a third of the catalogue that never speaks — and the
49 each hand-write the path it lands at, which is provisioning done badly
by hand.
The bootstrap argument that made it ambient was narrower than it looked.
"A provisioner needs an account before it can run" is true of a provisioner
process and says nothing about a provision the controller answers, and the
controller is not waiting on a bus account to compose one.
So: the mesh-broker seat delivers mesh-bus; a module requires it and gets an
address, a sealed credential and the trust to verify the server; a module
that requires nothing has no account at all. The requirement delivers the
connection, the declarations shape the authority, and declaring a subject
without requiring the bus is refused as incoherent.
mesh-bus and nats are deliberately two names: a module may run its own NATS
as a backing service exactly as one provides amqp, and a manifest saying
"nats" would otherwise mean either the mesh's nervous system or a private
queue.
The seat's Delivers was wrong twice today — amqp, then empty — and the
comment says so rather than reading as though it were always right.
0117 went a step further than it had grounds for. It was right that the bus
is the only bus, and wrong that the amqp interface must therefore retire —
because it conflated two reasons to want a broker. Using one to reach
another module is a second bus and stays refused. Needing an AMQP broker as
a backing service, the way something needs a database, is ordinary, and
forbidding it would make the mesh unable to run normal software while
calling that architecture.
So the broker becomes a plain provider module: no seat, not foundation,
never raised at genesis, no retirement condition. lavinmq now claims nothing
and provides amqp; nats claims mesh-broker and provides nothing.
The rule that survives is about direction, not software: inter-module
communication goes over the bus. A module may hold a broker for itself; it
may not use one as a channel to another module. That is a review judgement
where 0117 could have used a parser, which is the honest cost.
0106's progressive insight was itself wrong and is corrected by a second one
there — nothing moves off the old broker, so its "one purpose" sentence does
not become true, it is just not what that server is.
The insight check needed two fixes it found itself: a date may carry
trailing words, and a bold run with a link is discussing an insight rather
than marking one. All four bad shapes still fire.
29 put a module's events and tools in one namespace, 25 kept mesh.events.*
and mesh.tools.*. One namespace is right — a module's authority over its own
name becomes a single pattern the server enforces — but it needs a kind
token, because a stream is a subject filter and mesh.mod.*.> would persist
every tool call in the mesh. Tools stay on core NATS for the reason 25
already gives.
So: mesh.mod.<module>.event.<name>, .tool.<name>, and seats the same shape.
Versioning: additive is free; a breaking change is refused while callers are
bound, and the refusal names them, because the mesh already holds the uses
graph; a real break versions the subject, not the seat name, so the role
does not fork; binding is a recorded pin, not a drift to whatever is newest.
Semantic change stays open — no fingerprint sees it, and saying so beats
implying the check is complete.
Provisioning: a provisioner's create/remove/holds IS a serves protocol, so a
provision interface is a seat that also delivers a credential — which is why
design 26 already allowed that. The per-consumer resource is what stops the
two collapsing into one.
Secrets: sealed, so the bus is never trusted with plaintext — but sealed is
not enough, because a stream persists and a durable ciphertext is an archive
the day a key leaks. So a secret never enters a stream: core request/reply
only, and a declaration names a secret rather than carrying one, which is
0098's fetch-don't-store applied where carrying is worst. The vault's own
credential and the bus's own accounts are the two bootstrap exceptions,
resolved the way 0067 resolves the control plane.
Also rewrote the addresses paragraph, which was too compressed to follow:
on-bus addresses disappear because nothing stores them, off-bus ones are
untouched and still 0098's problem, and the bus's own address is the one
that cannot be a subject.
The architecture 0117 opened needs a module to offer a service as a role on
the bus — one holder, addressed by what it does. A closed table in the
controller cannot express that: a capability a module contributes would
require changing the mesh itself.
But 0110 closed the set for a good reason — nothing could say what seats a
mesh had, and the hand count came out at eleven of thirteen. That argues for
enumerable, not hardcoded, and 0110 weighed free-form against a fixed table
without considering a third option: closed at any moment and derived from
the catalogue. A derived list cannot drift, which is how the count broke.
So: the mesh's seats stay the mesh's, reserved by the mesh- prefix so the
prefix is the rule and there is no list to maintain; ten seats are renamed
to restore 0079's convention; everything 0110 decided about what a seat IS
survives untouched.
Design 29 carries the declaration model: three namespaces, subjects derived
from local names so a manifest survives the wire changing, queues never
declared, five relationships (the job and state shapes 0041 had no room
for), and the build-publish-deploy lifecycle with hard, soft and build-time
dependencies distinguished.
0041 gets a progressive insight: "no per-consumer setup, only a
subscription" was a fact about a topic exchange, and a JetStream durable
consumer is a real object someone creates.
WBS 1.3/1.4 were wrong and say so: streams come at registration and
consumers at assignment, so only the foundation set belongs at genesis.
jschoubben