Issue 143: correct the diagnosis — the step exists and did not fire

The first account said the declaration carries no resource that would disable the
found firewall and that nothing implemented the sentence the flip prints. Wrong:
the mechanism is a step in the host's own apply, retireFirewall, and it is careful
— it reads back that the mesh's table is loaded before retiring anything, records
the forward policies first, and verifies ufw reports inactive afterwards.

What is established: ufw was active and enabled two minutes after a flip that
reported the node converged with nothing failed; and the machine's record now
reads disabled_by_mesh: true, written by a reconcile fifty minutes later that
found ufw already inactive because an operator had disabled it by hand.

So the step did not take effect and the record says it did. The candidates are
named rather than chosen — the step is skipped silently when the apply has any
failure, the mesh's table is loaded by a service in the same apply so ordering is
open, and the host's detail lines do not reach the journal, which is why this has
candidates instead of a cause.

00-META/checks/records.py

@@ -164,6 +164,12 @@ def check_rests_on(failures, records):
                 # decision is exactly what as-is is for."
                 if rel(path).startswith("03-DESIGN/00-as-is/"):
                     continue
+                # A withdrawn record's citations are history. It instructs nobody -- every reader
+                # is sent to its superseder -- so what it was built on may itself be withdrawn.
+                # Refusing that would mean rewriting the lineage of a record whose reasoning is
+                # the thing the immutability rule protects.
+                if frontmatter(read(path)).get("status") == "superseded":
+                    continue
                 # An extension that supersedes legitimately names what it replaced.
                 this = ADR_FILE.match(os.path.basename(path))
                 supersedes = records[number]["front"].get("superseded-by", "")
@@ -241,13 +247,20 @@ def check_supersession_symmetry(failures, records):
             failures.add("supersession", rel(record["path"]), f"superseder does not exist: {by}")
             continue
         other = records[match.group(1)]
-        claims = os.path.basename(str(other["front"].get("supersedes", "")))
-        if claims != record["name"]:
+        # `supersedes:` may name one record or several. One decision replacing two is a real
+        # situation -- two records that built and refined the same wrong mechanism are withdrawn
+        # by the one record that removes it -- and a check that allows only one would force
+        # either a chain of pro-forma records or an unmarked supersession.
+        claimed = other["front"].get("supersedes", "")
+        if isinstance(claimed, str):
+            claimed = [claimed] if claimed else []
+        claims = [os.path.basename(str(entry)) for entry in claimed]
+        if record["name"] not in claims:
             failures.add(
                 "supersession",
                 rel(other["path"]),
                 f"ADR {number} says this supersedes it; this record does not say so "
-                f"(supersedes: {claims or 'absent'})",
+                f"(supersedes: {', '.join(claims) or 'absent'})",
             )
 
 

02-DECISIONS/0137-a-machine-says-which-networks-it-routes.md

@@ -1,10 +1,11 @@
 ---
 topic: what runs on it
-status: accepted
+status: superseded
 date: 2026-09-28
 deciders: jochen
 extends: 02-DECISIONS/0100-a-node-in-use-is-adopted-before-it-is-converged.md
 reconstructed: false
+superseded-by: 02-DECISIONS/0140-the-filter-constrains-what-arrives-from-outside.md
 ---
 
 # 137. A machine says which networks it routes

02-DECISIONS/0139-a-network-is-forwarded-because-a-module-declared-it.md

@@ -1,10 +1,11 @@
 ---
 topic: what runs on it
-status: accepted
+status: superseded
 date: 2026-09-28
 deciders: jochen
 reconstructed: false
 extends: 02-DECISIONS/0137-a-machine-says-which-networks-it-routes.md
+superseded-by: 02-DECISIONS/0140-the-filter-constrains-what-arrives-from-outside.md
 ---
 
 # 139. A network is forwarded because a module declared it

02-DECISIONS/0140-the-filter-constrains-what-arrives-from-outside.md

@@ -0,0 +1,146 @@
+---
+topic: what runs on it
+status: accepted
+date: 2026-09-28
+deciders: jochen
+reconstructed: false
+extends: 02-DECISIONS/0045-a-machine-firewall-is-the-sum-of-what-it-listens-on.md
+supersedes:
+  - 02-DECISIONS/0137-a-machine-says-which-networks-it-routes.md
+  - 02-DECISIONS/0139-a-network-is-forwarded-because-a-module-declared-it.md
+---
+
+# 140. The filter constrains what arrives from outside, and says nothing about a machine's own guests
+
+## Context
+
+The filter the mesh derives blocks traffic passing *through* a machine unless something allows it,
+because a container's published port is traffic passing through rather than traffic arriving at the
+machine itself ([ADR 0100](0100-a-node-in-use-is-adopted-before-it-is-converged.md),
+[issue 047](../04-ISSUES/047-the-firewall-does-not-cover-published-container-ports/00-report.md)).
+Having blocked all of it, the filter then had to let the machine's own containers reach outward again.
+It does that by listing the address ranges those containers sit on.
+
+As rendered on a converged workstation today:
+
+```
+policy drop
+ct state established,related accept
+ip saddr 172.16.0.0/12 accept
+ip saddr 192.168.128.0/17 accept
+ip saddr 10.0.0.0/8 accept
+ip saddr 192.168.16.0/20 accept
+... four more
+```
+
+Two of those ranges were constants in the control plane's source. The rest were typed by the operator
+after [ADR 0137](0137-a-machine-says-which-networks-it-routes.md), which existed to make the typing
+possible, because converging that workstation had cut every one of its containers off from the
+internet and nothing reported a fault
+([issue 137](../04-ISSUES/137-converging-a-machine-cut-off-its-own-guests/00-report.md)).
+
+**The list is the mistake, not its contents.** Every attempt to make it correct fails the same way.
+A constant describes one machine. A typed range goes stale, and cannot tell a network the mesh made
+from one a predecessor left behind — measured on the control-node, where six such ranges fall outside
+the constants and two of the six belong to services the mesh does not run
+([issue 141](../04-ISSUES/141-the-forward-chain-does-not-follow-the-modules/00-report.md)).
+[ADR 0139](0139-a-network-is-forwarded-because-a-module-declared-it.md) tried to generate the same
+list from the modules and put half the rule set on the machine to do it. Three records, one list, and
+the list should not exist.
+
+**Because the mesh has no policy about a container reaching outward.** What the filter is for is
+stated in [ADR 0045](0045-a-machine-firewall-is-the-sum-of-what-it-listens-on.md): which port is open,
+and to whom. That is about what arrives. A container of this machine's own opening a connection to
+something else is not a port being opened to anybody, and enumerating the addresses it might do so
+from is bookkeeping about the machine's internal plumbing, which the mesh neither owns nor can know.
+
+**The system being replaced never had this fault, and its rule says why.** The chain still protecting
+the control-node applies only to traffic arriving on that machine's outward link, and leaves
+everything else alone. The mesh's filter dropped that distinction and replaced it with a list of
+addresses.
+
+## Considered Options
+
+1. **Keep the list and generate it better** — from the modules' declared networks, or from what the
+   machine reports. Rejected: [ADR 0139](0139-a-network-is-forwarded-because-a-module-declared-it.md)
+   is that, and it puts part of the rule set on the machine, which makes the rule set partly the
+   machine's and the derivation advisory.
+2. **Name the guest links instead of their addresses, and allow only those.** Rejected as more than is
+   needed: it fails in the safe direction, but it is still a list that has to keep up with the
+   machine, and the thing it protects against — a container reaching outward — is not a thing the mesh
+   has a position on.
+3. **Do not block traffic passing through at all.** Rejected: that is
+   [issue 047](../04-ISSUES/047-the-firewall-does-not-cover-published-container-ports/00-report.md),
+   where a published port was reachable from anywhere because no rule mentioned it.
+4. **Constrain what arrives from outside, and nothing else.** Adopted.
+
+## Decision
+
+**The filter constrains traffic arriving from outside the machine, and says nothing about traffic that
+did not.** Traffic passing through the machine is allowed unless it arrived on one of the machine's
+outward links, in which case it is allowed only where a declared endpoint's reach admits it
+([ADR 0138](0138-an-assignment-binds-an-endpoint-and-says-how-far-it-reaches.md)). A container of this
+machine's own reaching anywhere is not filtered, because the mesh has no position on it.
+
+**A machine says which of its links face outside.** One node-level fact, reported by the machine the
+way it already reports the kind of firewall it found and the tunnel it carries — not a setting, not a
+list of addresses, and not something anybody types. It does not change when a module is added or
+removed, which is what separates it from the list it replaces.
+
+**A machine that has reported no outward link is sent no filter.** Rendering a rule around a link
+whose name is not known produces a rule set that does not load, which is a machine filtering nothing
+while its unit reports success. The refusal happens in the control plane, where a person reads it, and
+the machine keeps the filter it already has.
+
+**No addresses of the machine's own networks appear in the filter.** The two constants are removed and
+`node networks` is removed with them, along with everything any machine was told to say through it.
+Ports continue to follow the modules exactly as before: a module assigned to a machine opens the port
+its assignment says it reaches on, and nothing about a network is said anywhere.
+
+## Consequences
+
+- **Three records collapse into one rule.** 0137 and 0139 are superseded. What 0137 was right about —
+  that converging a machine had silently cut off its own containers, and that nothing previewed it — is
+  answered by removing the cause rather than by giving the operator a way to compensate for it.
+- **Every machine already converged loses its declared ranges and keeps working**, because the traffic
+  those ranges allowed is now allowed by not having arrived from outside. The workstation's five ranges
+  and the laptop's one are deleted rather than migrated.
+- **A machine's test beds stop being a special case.** A bed's network is created while the machine
+  runs and was the case no list could cover; it is now covered by not being mentioned.
+- **A new fact travels in the report**, and the control plane refuses to compose a filter without it,
+  so the order of the roll-out matters: the machines report before the control plane depends on it.
+- **A machine with more than one outward link says so**, and a machine that acquires one while the mesh
+  is not looking is treated as internal until its next report. That window is the cost of this shape;
+  it is bounded by the report interval, and it exists on machines whose outward link changes, which
+  are the machines with nothing published to the outside.
+- **What got harder:** nothing in the declaration, and one more thing a machine must be able to work
+  out about itself. A machine that cannot say which link faces outside cannot be given a filter.
+
+## How it is checked
+
+- **A machine's own container reaches outward with no network named anywhere.** A bed converges a
+  machine carrying containers on several networks, none of them mentioned in any setting, and each
+  reaches out afterwards. This fails against the previous behaviour, where the same flip cut them off,
+  and that is how it is written.
+- **A port declared reachable from outside is reachable; one that is not, is not.** Probed from off the
+  machine's private network, for a published port and for an undeclared one, before and after the flip.
+- **A network created after the filter was composed needs no new filter.** A network is made on the
+  machine after its last declaration and a container on it reaches out, with nothing re-sent.
+- **No address of a machine's own networks appears in a rendered filter**, asserted on the text so a
+  range cannot creep back in.
+- **A machine that reports no outward link is sent no filter, and the refusal names it** — asserted in
+  the control plane, and that the machine's existing filter is left alone.
+- **A machine reporting two outward links has both constrained**, asserted per chain body so a rule
+  covering one and not the other cannot pass.
+
+## References
+
+- [ADR 0045](0045-a-machine-firewall-is-the-sum-of-what-it-listens-on.md) — what the filter is for
+- [ADR 0138](0138-an-assignment-binds-an-endpoint-and-says-how-far-it-reaches.md) — what admits traffic
+  arriving from outside
+- [ADR 0100](0100-a-node-in-use-is-adopted-before-it-is-converged.md) — why traffic passing through is
+  filtered at all
+- [ADR 0137](0137-a-machine-says-which-networks-it-routes.md),
+  [ADR 0139](0139-a-network-is-forwarded-because-a-module-declared-it.md) — superseded here
+- [issue 137](../04-ISSUES/137-converging-a-machine-cut-off-its-own-guests/00-report.md),
+  [issue 141](../04-ISSUES/141-the-forward-chain-does-not-follow-the-modules/00-report.md)

02-DECISIONS/0141-the-host-delivers-its-own-successor.md

@@ -0,0 +1,154 @@
+---
+topic: what runs on it
+status: accepted
+date: 2026-09-29
+deciders: jochen
+reconstructed: false
+extends: 02-DECISIONS/0005-the-node-host.md
+---
+
+# 141. The host delivers its own successor, and versions live side by side
+
+## Context
+
+[Issue 142](../04-ISSUES/142-the-host-is-the-one-thing-the-mesh-does-not-deliver/00-report.md). A
+merge builds every changed module and the control plane — which is itself a module — and the result
+reaches the machines running it with nobody asking. The host is the exception: it is not a build
+target, no declaration delivers it, and every machine in this mesh runs a byte-identical binary that
+somebody built on a workstation and copied out.
+
+The half that *recovers* from a bad host exists. `internal/upgrade` can tell that the executable this
+process started from was replaced on disk, and it records which version last completed a reconcile.
+The launcher counts consecutive failed starts, calls a rollback at the limit, and treats a clean exit
+as the host standing aside so that the next loop runs whatever is on disk now. That supervision is
+complete and correct.
+
+Two things make it dead code:
+
+- **`Replaced()` is called by nothing but its own tests.** Nothing tells the running host that a
+  successor is waiting.
+- **The rollback resolves a version through the machine's package manager** — `pacman -U` from the
+  package cache. No machine here has the host installed as a package, so the recovery cannot run on
+  any of them; and being written in one package manager's terms, it cannot run on two of the three
+  operating systems the host is built for — [ADR 0005](0005-the-node-host.md) builds one binary per
+  operating system, pinned at link time.
+
+**The record already points at the answer.** What is kept is a *version*, not a path. Keeping a
+version is only useful to something that can choose between versions present on the machine, which is
+what the package manager was being asked to do. The versions can simply be on disk.
+
+## Considered Options
+
+1. **Deliver the host as a package, as the rollback assumes.** Rejected: it needs a package built and
+   a repository trusted per operating system, three of each, and the existing `package` resource
+   asserts presence and deliberately never a version — "version is the package manager's business and
+   the mesh does not hold a second opinion about it" — so it cannot ask for a particular host anyway.
+   Heaviest of the three and the only one that is different on every machine.
+2. **Write the new binary over the running one.** Rejected on a fact: a running executable cannot be
+   truncated, and `archive` opens what it unpacks with `O_TRUNC`. It could be made to write and
+   rename, which is better hygiene and worth doing for its own sake, but it buys nothing here that
+   option 3 does not, and it leaves rollback with nowhere to go back to.
+3. **Versions side by side; the newest retires the old.** Adopted.
+
+## Decision
+
+**A host version is delivered as an archive into a directory named for it, and never over a running
+one.** The declaration names it like any other archive — fetched by digest, the digest checked before
+anything is unpacked. Nothing new travels, no new resource kind, and no change to how archives are
+applied, because the path being written is not the path being executed.
+
+**The launcher starts the most recently delivered version.** That is what "the newest" means: the
+version whose directory arrived last. It reads no pointer and follows no link — the mesh creates no
+links ([ADR 0012](0012-the-mesh-creates-no-symlinks.md)) — and the version is in the path, so nothing
+has to be told what is running.
+
+**The running host stands aside for a successor, and only between reconciles.** Finding a newer
+version delivered, it finishes the reconcile it is in and exits cleanly. The launcher already reads a
+clean exit as exactly this and starts what is on disk now. A host that stood aside mid-apply is the
+half-configured machine this project exists to prevent, so the check happens at the boundary and
+nowhere else.
+
+**A version that completes a reconcile records itself, and retires what came before it.** The
+known-good record is written as it is today. Then versions older than the one before the running one
+are removed: the running version and its predecessor are kept, which is exactly what a rollback
+needs, and nothing else accumulates.
+
+**Rollback starts the previous version instead of reinstalling a package.** At the failure limit the
+launcher pins the known-good version and starts that, once. The second failure is still a different
+diagnosis — the previously working version does not run either, so it is the machine and not the
+binary — and the halt is unchanged. No package manager, no package cache, and the same script on every
+operating system.
+
+**A machine says which host version it is running,** on the report it already sends, beside the other
+facts it states about itself. Without it nothing can say a machine is behind, so "every machine
+current with its source" cannot include the host.
+
+## Progressive insight — 2026-09-29, the same day
+
+**The delivery is not "nothing new", and this record said it was.** The decision above stands and is
+built: versions side by side, the newest runs, the running host stands aside between reconciles, a
+completed reconcile retires what is older than the predecessor, rollback picks a directory. What was
+wrong was a claim about how a version reaches a machine. The paragraph on delivery said the
+declaration "names it like any other archive… nothing new travels, no new resource kind"; the second
+half is true and the first is not, because two things the delivery needs do not exist:
+
+- **Nothing can compile it.** A `bundle` artifact is compiled by a closed list of toolchains —
+  typescript and python — whose own comment says adding a language is a decision, because a language
+  used by *modules* needs an SDK carrying the broker client, the event envelope and tool serving. The
+  host uses none of that: it is what applies modules, not one of them. So the obligation that list
+  warns about attaches to a module written in a language, not to the language being buildable, and
+  the control plane — also written in Go — is built as an image from a Dockerfile rather than through
+  a toolchain at all.
+- **A version cannot reach the path.** An `archive` resource names a fixed path in the manifest, and
+  nothing interpolates the built version into it, so nothing can ask for
+  `…/versions/<version>/`.
+
+Neither changes what was decided, which options were weighed, or any consequence: the shape is
+unaffected and the host half is merged and tested. What it changes is the cost, which this record
+understated as none. The remaining work is a way to build the host and a way to name a version in a
+path, and until both exist nothing delivers a version and every machine takes the fallback — which is
+what every machine does today.
+
+## Consequences
+
+- **The host becomes a build target and a module** — a module whose resource is the next host, applied
+  by the host that is running. The bootstrap is not circular because the two are different versions in
+  different directories.
+- **Rollback becomes usable on every machine**, having been usable on none. It also stops being
+  written in one operating system's terms.
+- **One copy by hand remains, once.** The first host that understands versioned directories cannot be
+  fetched by a host that does not. That copy is the last, and it is the honest cost of the change
+  rather than a step in the design.
+- **Two versions occupy disk instead of one.** About nine megabytes. The predecessor is the price of a
+  rollback that does not depend on a cache somebody else may clean.
+- **What got harder:** a host must now be able to find its own successor and to judge when it is safe
+  to stand aside. Both are between reconciles, which is the only moment the host is not mid-change.
+- **A machine that is never told a newer version keeps running what it has**, indefinitely and
+  visibly, because its report says which version that is.
+
+## How it is checked
+
+- **A delivered version is run, and the old one is not.** A bed delivers a second version to a machine
+  running the first; the host exits between reconciles, the launcher starts the new one, and the
+  machine reports the new version. This fails against the previous behaviour, where nothing notices a
+  delivered version at all.
+- **It stands aside between reconciles and never inside one.** Asserted by delivering a version while
+  an apply is in flight: the apply completes, and the exit follows it.
+- **A version that will not start is rolled back to its predecessor, once**, and the second failure
+  halts with the machine named rather than the binary — asserted with no package manager involved.
+- **A completed reconcile retires what is older than the predecessor**, and never the predecessor
+  itself, because that is what a rollback needs. Asserted on the directory afterwards.
+- **The report names the running version**, asserted end to end rather than on the function that reads
+  it, since the point is that the control plane can tell a machine is behind.
+- **The launcher picks the newest delivered version** with no pointer file and no link, asserted by
+  delivering two and checking which runs.
+
+## References
+
+- [ADR 0005](0005-the-node-host.md) — the host, and what its supervision is for
+- [ADR 0010](0010-delivery.md) — a declaration is owned resources; this adds no kind to it
+- [ADR 0012](0012-the-mesh-creates-no-symlinks.md) — why the version is in the path
+- [ADR 0005](0005-the-node-host.md), *it is built per operating system* — why a rollback written in
+  one package manager's terms was wrong for two of three
+- [issue 142](../04-ISSUES/142-the-host-is-the-one-thing-the-mesh-does-not-deliver/00-report.md) — the
+  measurement

02-DECISIONS/0142-the-mesh-delivers-its-own-components-as-binaries.md

@@ -0,0 +1,158 @@
+---
+topic: the mesh
+status: accepted
+date: 2026-09-29
+deciders: jochen
+reconstructed: false
+extends: 02-DECISIONS/0141-the-host-delivers-its-own-successor.md
+---
+
+# 142. The mesh delivers its own components as binaries, not as container images
+
+## Context
+
+Measured on the control-node, 2026-09-29:
+
+| what | how it runs | publishes |
+|---|---|---|
+| host | a binary on the machine | — |
+| controller, catalogue, builder, vault | containers | nothing |
+| store, registry, broker | containers | ports |
+
+**The mesh's own software is delivered two ways, and the difference is not a property of the
+software.** The host and the controller are both written in the same language, both the mesh's own,
+both doing the mesh's own work. One is an image fetched from a registry. The other is a file somebody
+copied to four machines, owned by no package, built by nothing
+([issue 142](../04-ISSUES/142-the-host-is-the-one-thing-the-mesh-does-not-deliver/00-report.md)).
+
+**The reason is not a judgement about either, it is that images are the only delivery that works.**
+There is no way to put a binary on a machine. The host is hand-copied because of that, and the
+controller is an image because of that. Neither was chosen on its merits.
+
+What it costs, all of it measured rather than argued:
+
+- **Genesis must raise a container runtime before the control plane can exist.** The bundle carries
+  three images and one of them is the controller, *"in the bundle for the same reason they are: there
+  is nothing to fetch it with yet"*
+  ([design 07](../03-DESIGN/01-to-be/07-the-foundation.md)). So the hardest moment in the mesh's life
+  has a prerequisite that the thing being started does not need.
+- **Updating the control plane depends on the control plane.** Its image is fetched from the registry,
+  which is a container the controller manages.
+- **A change to the host cannot be rolled out at all.** Every machine here runs a byte-identical
+  hand-copied binary. A change merged yesterday reached none of them.
+- **Compiling the language the mesh is written in is not a capability of the builder.** The bundle
+  toolchains are typescript — real, with a registered base module — and python, which is named in the
+  list and absent from the catalogue. The controller is built as an image from a Dockerfile, which is
+  the per-repository incantation the bundle toolchain exists to abolish
+  ([design 18](../03-DESIGN/01-to-be/18-building-a-module.md)).
+
+The half that *receives* a binary safely is already built and tested
+([ADR 0141](0141-the-host-delivers-its-own-successor.md)): versions side by side in directories named
+for them, the newest run, the running one standing aside between reconciles, retirement keeping the
+predecessor, and a rollback that chooses a directory. What is missing is everything that puts one
+there.
+
+## Considered Options
+
+1. **Leave it as it is.** Rejected: it is not a design, it is the reach of one mechanism. And it is
+   what makes a host change undeliverable.
+2. **Containerise the host too**, so everything is delivered one way. Rejected: the host is what
+   starts the container runtime and what applies containers. A host in a container is the bootstrap
+   problem made total, and the machine would have no way back from a bad one.
+3. **Deliver the mesh's components as operating-system packages.** Rejected for the reason
+   [ADR 0141](0141-the-host-delivers-its-own-successor.md) rejected it for the host: a package and a
+   trusted repository per operating system, three of each, and the `package` resource asserts presence
+   and deliberately never a version.
+4. **Binaries for the mesh's own components, containers for third-party software.** Adopted.
+
+## Decision
+
+**The mesh's own components are delivered as binaries on the machine.** The host, the controller, the
+catalogue, the builder, the vault — the software this project writes. They are delivered by the
+mechanism [ADR 0141](0141-the-host-delivers-its-own-successor.md) built: an archive, fetched by
+digest, unpacked into a directory named for its version, with the running one standing aside between
+reconciles and a rollback that chooses the predecessor.
+
+**Third-party software stays a container.** The store, the registry, the broker. They are somebody
+else's build, they are already adopted as modules
+([ADR 0078](0078-the-store-and-broker-are-modules.md)), and an image is the right way to carry
+somebody else's software. **The container runtime remains required** — modules use it — so this
+removes a dependency from the control plane, not from the machine.
+
+**The builder compiles the languages the mesh is written in.** A toolchain for Go, with a base module
+providing the compiler, exactly as typescript has. The obligation the toolchain list warns about — an
+SDK carrying the broker client, the envelope and tool serving — attaches to a *module* written in a
+language, not to the language being compilable. None of these components is a module in that sense;
+the host is what applies modules.
+
+**An artifact says what it targets.** A compiled binary is per operating system, pinned at link time
+([ADR 0005](0005-the-node-host.md)), and a toolchain deliberately takes nothing from the module,
+because anything a module could override there it would be writing a Dockerfile to override. So the
+target is a property of the artifact rather than of the recipe, and one artifact declared per target
+is one build each.
+
+**A component's version comes from where it sits, not from its linker.** It is unpacked into a
+directory named for its version, so it can read its own version from its path. The stamp goes, and
+with it the need for a build to know what it will be called.
+
+**Genesis carries a binary reference where it carried an image reference.** The principle does not
+change — the bundle names a thing by digest and the host fetches it, pinned because nothing can
+resolve a version when no mesh exists — and the container runtime stops being a prerequisite for the
+control plane. It stays a prerequisite for the store and the broker, which is where it belongs.
+
+**The order is staged, and each step stands alone.** Compiling Go; an artifact naming its target;
+delivering a binary; the host as the first component delivered; the controller, catalogue, builder and
+vault out of their containers; genesis last. Genesis is last for the reason it is always last: it
+matters for a machine nobody has yet, and every earlier step is provable on a mesh that exists.
+
+## Consequences
+
+- **One delivery for the mesh's own software**, so a change to the host ships the way a change to the
+  controller does, and neither is copied by hand.
+- **The control plane stops depending on a container runtime and on its own registry.** Both remain on
+  the machine for other reasons; neither gates the control plane's own life any more.
+- **`Replaced()`, the known-good record and the launcher's rollback stop being dead code.** They were
+  written for this and have been called by nothing but their tests.
+- **Four more components gain a rollback they do not have.** Today a bad controller image is recovered
+  by an operator; under this it is recovered the way a bad host is.
+- **Two versions of each component occupy disk.** Around nine megabytes each. The predecessor is what a
+  rollback needs.
+- **Genesis gets smaller, not larger.** One fewer image to carry and one fewer runtime to raise before
+  the control plane.
+- **This does not make the components smaller or simpler.** They are the same programs; what changes is
+  how they arrive. A reader expecting the containers to have been hiding complexity will not find any.
+- **What got harder:** the builder gains a language, artifacts gain a target, and the mesh gains a
+  second kind of thing it must deliver correctly — one where getting it wrong takes the control plane
+  down rather than a module. That is why the host is first: it is the component whose recovery is
+  already built and tested.
+
+## How it is checked
+
+- **A component is delivered and runs, with nothing copied by hand.** A bed builds the host from its
+  repository, delivers it to a machine running an older one, and the machine reports the new version.
+  This fails today at the first step, because nothing builds it.
+- **Each target is built once and only the matching one is delivered.** Asserted by declaring an
+  artifact per operating system and checking that a machine is offered the one it can run — a host
+  built for another is what ADR 0005's link-time pin exists to refuse.
+- **A component reads its version from its path**, asserted by unpacking the same bytes into two
+  differently named directories and seeing each report its own.
+- **A bad component is rolled back without an operator**, for the host first: a version that will not
+  start is replaced by its predecessor once, and the second failure halts naming the machine.
+- **The control plane comes up with no registry reachable**, which is the dependency this removes —
+  asserted by raising it with the registry stopped.
+- **Genesis raises a control plane with no container runtime running**, and raises the store and the
+  broker afterwards. Last, and on a machine with nothing on it.
+- **A published port count that does not change.** The mesh's own components publish nothing today, so
+  moving them out of containers must not open anything — asserted on the machine's reachable set before
+  and after, which the converge preview already reads.
+
+## References
+
+- [ADR 0141](0141-the-host-delivers-its-own-successor.md) — the receiving half, already built
+- [ADR 0005](0005-the-node-host.md) — the host, its supervision, and one binary per operating system
+- [ADR 0078](0078-the-store-and-broker-are-modules.md) — why third-party software stays a container
+- [ADR 0006](0006-the-substrate-and-the-control-plane.md) — what genesis must raise, and in what order
+- [issue 142](../04-ISSUES/142-the-host-is-the-one-thing-the-mesh-does-not-deliver/00-report.md) — the
+  measurement that started this
+- [design 07](../03-DESIGN/01-to-be/07-the-foundation.md) — the bundle's three images, one of them the
+  controller

02-DECISIONS/README.md

@@ -142,6 +142,7 @@ python3 00-META/checks/index.py            fail if stale
 - **0131** — [Everything on the mesh speaks to the broker seat, and AMQP is not a provision](0131-everything-on-the-mesh-speaks-to-the-broker-seat.md)
 - **0132** — [A seat carries the tools its holder must serve](0132-a-seat-carries-the-tools-its-holder-must-serve.md)
 - **0134** — [The mesh says what it applied](0134-the-mesh-says-what-it-applied.md)
+- **0142** — [The mesh delivers its own components as binaries, not as container images](0142-the-mesh-delivers-its-own-components-as-binaries.md)
 
 ### Its tiers, from the bottom up
 
@@ -217,9 +218,11 @@ python3 00-META/checks/index.py            fail if stale
 - **0133** — [A module owns its migrations, and the mesh owns when they run](0133-a-module-owns-its-migrations-and-the-mesh-owns-when-they-run.md)  *(superseded)*
 - **0135** — [A module version prepares its state before it runs](0135-a-module-version-prepares-its-state-before-it-runs.md)
 - **0136** — [A step gates its module, not the machine](0136-a-step-gates-its-module-not-the-machine.md)
-- **0137** — [A machine says which networks it routes](0137-a-machine-says-which-networks-it-routes.md)
+- **0137** — [A machine says which networks it routes](0137-a-machine-says-which-networks-it-routes.md)  *(superseded)*
 - **0138** — [An assignment binds an endpoint and says how far it reaches](0138-an-assignment-binds-an-endpoint-and-says-how-far-it-reaches.md)
-- **0139** — [A network is forwarded because a module declared it](0139-a-network-is-forwarded-because-a-module-declared-it.md)
+- **0139** — [A network is forwarded because a module declared it](0139-a-network-is-forwarded-because-a-module-declared-it.md)  *(superseded)*
+- **0140** — [The filter constrains what arrives from outside, and says nothing about a machine's own guests](0140-the-filter-constrains-what-arrives-from-outside.md)
+- **0141** — [The host delivers its own successor, and versions live side by side](0141-the-host-delivers-its-own-successor.md)
 
 ### How it is built
 

03-DESIGN/01-to-be/05-the-node-host.md

@@ -2,8 +2,9 @@
 layer: to-be
 status: in-progress
 code: [mesh-host]
-updated: 2026-09-22
+updated: 2026-09-29
 decisions:
+  - 02-DECISIONS/0141-the-host-delivers-its-own-successor.md
   - 02-DECISIONS/0100-a-node-in-use-is-adopted-before-it-is-converged.md
   - 02-DECISIONS/0102-the-mesh-writes-into-a-shared-file-never-over-it.md
   - 02-DECISIONS/0103-what-an-adopted-node-holds-and-what-its-guard-refuses.md
@@ -423,3 +424,45 @@ ignored an instruction and "applied" would be a lie. Applying stays one at a tim
 is not. **Checked** by the link's unit tests on the drain, and by the genesis bed's settle wait,
 which counts on a node catching up to the newest declaration rather than the oldest.
 
+## The host delivers its own successor
+
+*2026-09-29, from a change to the host that could reach no machine —
+[issue 142](../../04-ISSUES/142-the-host-is-the-one-thing-the-mesh-does-not-deliver/00-report.md),
+settled by [ADR 0141](../../02-DECISIONS/0141-the-host-delivers-its-own-successor.md).*
+
+A merge builds every changed module and the control plane, and the result reaches the machines running
+it with nobody asking. The host was the exception: not a build target, named by no declaration, and
+identical on every machine because somebody had copied it there.
+
+The supervision needed for this was already right. A clean exit from the host means it has stood aside,
+and the launcher's next turn runs whatever is on disk. Consecutive failed starts are counted, a
+rollback happens at the limit, and a second failure halts with the machine named rather than the binary.
+What was missing was smaller than it looked: nothing told the running host a successor was waiting, and
+the rollback resolved its known-good *version* through one operating system's package manager, which no
+machine here used.
+
+Keeping a version rather than a path was the clue. That is only useful to something that can choose
+between versions present on the machine — so the versions live side by side:
+
+- **A version arrives as an archive, in a directory named for it.** The ordinary resource, fetched by
+  digest and checked before anything is unpacked. The path written is never the path being executed, so
+  replacing a running binary — which the kernel refuses — never comes up.
+- **The launcher starts the most recently delivered version**, reading no pointer and following no
+  link, because the version is in the path.
+- **The running host stands aside between reconciles and never inside one.** Standing aside mid-apply is
+  the half-configured machine this document exists to prevent.
+- **A version that completes a reconcile records itself and retires what is older than its
+  predecessor.** The predecessor stays, because that is what a rollback needs.
+- **Rollback starts that predecessor** instead of reinstalling a package: no package manager, no cache
+  somebody else may clean, and the same script on every operating system.
+- **A machine says which host version it runs**, on the report it already sends, so being behind is
+  answerable at all.
+
+One copy by hand remains, once: the first host that understands versioned directories cannot be fetched
+by a host that does not.
+
+*How it is checked* is stated with the decision — a second version delivered to a running machine is
+run and reported; the exit follows an in-flight apply rather than interrupting it; a version that will
+not start is rolled back once and the second failure halts; a completed reconcile retires what is older
+than the predecessor and never the predecessor; and the newest of two delivered versions is the one
+that runs.

03-DESIGN/01-to-be/07-the-foundation.md

@@ -11,8 +11,9 @@ code:
   - mesh-catalog modules/postgres
   - mesh-catalog modules/lavinmq
   - mesh-lab test/integration/mesh.test.ts (a bare machine becomes a mesh)
-updated: 2026-09-22
+updated: 2026-09-29
 decisions:
+  - 02-DECISIONS/0142-the-mesh-delivers-its-own-components-as-binaries.md
   - 02-DECISIONS/0100-a-node-in-use-is-adopted-before-it-is-converged.md
   - 02-DECISIONS/0088-the-foundation-filters-before-anything-listens.md
   - 02-DECISIONS/0004-a-node-and-how-it-joins.md
@@ -314,4 +315,24 @@ of a database and pushed to over the broker. What arrived and what did not is th
 
 **One fault, and it was in the joining.** The token did not say what the mesh calls the machine,
 so enrolment needed a flag its own help said it did not — and failed at the broker with an empty
-username. Recorded in ADR 0004 as the fifth thing a token carries.
+username. Recorded in ADR 0004 as the fifth thing a token carries.
+
+## The mesh's own components arrive as binaries
+
+*2026-09-29 —
+[ADR 0142](../../02-DECISIONS/0142-the-mesh-delivers-its-own-components-as-binaries.md).*
+
+The bundle carries three images and one of them is the controller, *because there is nothing to fetch
+it with yet*. That reasoning holds and its conclusion changes: the controller is carried as a **binary**
+reference rather than an image reference, pinned by digest exactly as before. Nothing about the bundle's
+shape moves — it names a thing and the host fetches it — and the container runtime stops being something
+genesis must raise before the control plane can exist. It still raises one, for the store and the broker,
+which is where somebody else's software belongs.
+
+The mesh's own components — the host, the controller, the catalogue, the builder, the vault — are
+delivered as binaries into directories named for their versions, by the mechanism
+[ADR 0141](../../02-DECISIONS/0141-the-host-delivers-its-own-successor.md) describes. Third-party
+software stays a container. The split is not about isolation; it is about who built the thing.
+
+Measured before deciding it: the mesh's own components publish no ports at all, so this opens nothing.
+Only the store, the registry and the broker publish, and they are staying as they are.

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

@@ -10,7 +10,7 @@ code:
 updated: 2026-09-28
 decisions:
   - 02-DECISIONS/0138-an-assignment-binds-an-endpoint-and-says-how-far-it-reaches.md
-  - 02-DECISIONS/0139-a-network-is-forwarded-because-a-module-declared-it.md
+  - 02-DECISIONS/0140-the-filter-constrains-what-arrives-from-outside.md
   - 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
@@ -627,41 +627,49 @@ the found firewall reloads and reachable from a container on the node, that a ma
 enrols through the openings before and after a reload and a reboot, and that after the flip the
 declared port is open and the undeclared one closed.
 
-### The networks it forwards are the ones its modules declared
+### It filters what arrives from outside, and not what the machine's own guests send
 
 *2026-09-28, preparing the control-node's convergence —
 [issue 141](../../04-ISSUES/141-the-forward-chain-does-not-follow-the-modules/00-report.md), settled by
+[ADR 0140](../../02-DECISIONS/0140-the-filter-constrains-what-arrives-from-outside.md), which replaces
+[ADR 0137](../../02-DECISIONS/0137-a-machine-says-which-networks-it-routes.md) and
 [ADR 0139](../../02-DECISIONS/0139-a-network-is-forwarded-because-a-module-declared-it.md).*
 
-The forward chain denies by default, so a machine's own guests have to be allowed back in. Until now
-that was two ranges named in the control plane and, since
-[ADR 0137](../../02-DECISIONS/0137-a-machine-says-which-networks-it-routes.md), a list a machine could
-add to. On the machine measured here, six of its container networks fell outside those ranges — and
-four of the six were networks the mesh's own modules had declared and the host had created, while two
-were the predecessor's leftovers. A range wide enough to keep the four keeps the two: a filter widened
-by hand to protect what should not be there.
+Traffic passing through a machine is filtered, because a container's published port is traffic passing
+through rather than traffic arriving at the machine itself. Having blocked it, the filter then had to
+let the machine's own containers reach outward again — and it did that by listing the address ranges
+they sit on. Two of those ranges were constants in this repository's code, and the rest were typed by an
+operator after the flip had already cut a workstation's containers off from everything.
 
-**A network is forwarded because a module declared it.** The forward chain forwards the networks of the
-modules assigned to that node and, by default, nothing else; a module unassigned stops being forwarded
-at the next reconcile. The control plane says which networks, by name, and the host — which created
-them — renders their addresses, because the runtime allocates the subnet and the host is what knows it.
-That keeps §4's shape and this document's: the mesh decides, the host applies.
+**The list was the mistake, not its contents.** A constant describes one machine. A typed range goes
+stale and cannot tell a network the mesh made from one a predecessor left behind — on the control-node,
+six ranges fall outside the constants and two of the six belong to services the mesh does not run. The
+attempt to generate the list from the modules put half the rule set on the machine and made the
+derivation advisory. Three records, one list.
 
-**This is derivation from the declaration, not from the machine.** 0137 rejected reading the machine,
-for two reasons that do not apply here: a network created between two declarations is already named in
-the one that asked for it, and a network nobody declared is never forwarded however it appeared. What
-0137's mechanism keeps is the case it was right for — guests no module declares, a test bed's range —
-added to the derived set and never replacing it.
+**And the mesh has no position on a container reaching outward.** §4 exists to say which port is open
+and to whom, which is about what arrives. A container of this machine's own opening a connection
+somewhere is not a port opened to anybody, and the addresses it might do that from are the machine's
+internal plumbing, which the mesh neither owns nor can know.
 
-The runtime's own default bridge, which a container attaches to when it names no module network, is the
-runtime's and not a module's, so the host renders it from what the runtime reports. With that, no range
-is named in the control plane at all.
+So the filter constrains what arrives from **outside** the machine and says nothing about what did not.
+Traffic passing through is allowed unless it came in on one of the machine's outward links, and then
+only where a declared endpoint's reach admits it (§6). The machine says which of its links face
+outside — one fact it reports, like the kind of firewall it found and the tunnel it carries, not a
+setting and not a list of addresses. It does not change when a module is added or removed, which is the
+whole difference from what it replaces. A machine that has reported no outward link is sent no filter
+at all, and keeps the one it has, because a rule written around a link with no name is a rule set that
+does not load — a machine filtering nothing while its unit reports success.
 
-*How it is checked:* a node with two modules declaring networks renders rules for exactly those two and
-none for a third present on the machine that nothing declared — which fails against forwarding by
-range, and is how it was written; unassigning one removes its rule at the next reconcile; the default
-bridge is asserted for a runtime whose bridge is somewhere other than the old constant named; and the
-guests of a declared network keep address and name service, per chain body.
+Ports go on following the modules exactly as before: assign a module to a machine and the port its
+assignment says it reaches on opens. Nothing about a network is said anywhere, by anybody.
+
+*How it is checked:* a bed converges a machine carrying containers on several networks, none of them
+named in any setting, and each reaches outward afterwards — which fails against the previous behaviour,
+where the same flip cut them off, and is how it was written; a network made *after* the last declaration
+needs no new filter; a declared port is reachable from off the private network and an undeclared one is
+not; no address of a machine's own networks appears in a rendered filter, asserted on the text; and a
+machine reporting no outward link is refused in the control plane with its existing filter left alone.
 
 ## 5 — Certificates
 

03-DESIGN/01-to-be/18-building-a-module.md

@@ -5,8 +5,9 @@ code:
   - mesh-controller cmd/mesh-builder
   - mesh-controller internal/builder
   - mesh-catalog modules/builder
-updated: 2026-09-25
+updated: 2026-09-29
 decisions:
+  - 02-DECISIONS/0142-the-mesh-delivers-its-own-components-as-binaries.md
   - 02-DECISIONS/0111-a-build-source-is-on-the-git-seat-or-external.md
   - 02-DECISIONS/0097-a-vendor-image-is-a-declared-build-input.md
   - 02-DECISIONS/0096-an-upstream-image-is-copied-between-registries.md
@@ -263,3 +264,27 @@ ships one and wrong for code the mesh built, which has no unit until the mesh wr
 
 **Tools, hooks and consumers are not further modes**, which is the test of whether three is the
 right number: they are loaded by a tool host, and a tool host is a process that stays up.
+
+## The builder compiles the languages the mesh is written in
+
+*2026-09-29 —
+[ADR 0142](../../02-DECISIONS/0142-the-mesh-delivers-its-own-components-as-binaries.md).*
+
+The toolchain list was typescript and python, and only typescript had a base module in the catalogue.
+Meanwhile the control plane — written in the language this project is mostly written in — was built as
+an image from a hand-written Dockerfile, which is the per-repository incantation this whole mechanism
+exists to abolish.
+
+So the list gains Go, with a base module providing the compiler exactly as typescript has one. The
+obligation the list's own comment warns about — an SDK carrying the broker client, the event envelope
+and tool serving — attaches to a **module** written in a language, not to the language being
+compilable. The mesh's own components are not modules in that sense; the host is what applies modules.
+
+**And an artifact says what it targets.** A compiled binary is per operating system, pinned at link
+time, and a toolchain deliberately accepts nothing from the module — anything a module could override
+there it would be writing a Dockerfile to override. The target is therefore a property of the artifact,
+not of the recipe: one artifact declared per target, one build each.
+
+A component's version stops being stamped in at link time. It is unpacked into a directory named for
+its version, so it reads its version from its own path, and a build no longer has to know what it will
+be called.

04-ISSUES/141-the-forward-chain-does-not-follow-the-modules/00-report.md

@@ -61,6 +61,18 @@ module declares — a test bed's pool — which is a much smaller residue than t
 has to know the runtime's allocations to tell whether that line is sufficient. On the machine
 measured here it read as though nothing needed saying.
 
+## What was decided
+
+*2026-09-28, later the same day.* The answer is not a better list. The question in the first open
+item below — should the chain be derived from the networks the modules declare — was answered *no*,
+after a converged machine's rendered rules were read: the chain blocks everything passing through the
+machine and then allows its own guests back by listing their addresses. Every route to a correct list
+fails, because the mesh has no position on a container reaching outward in the first place. The filter
+now constrains what arrives from **outside** the machine and says nothing about what did not, and a
+machine says which of its links face outside — one reported fact instead of a list. See
+[ADR 0140](../../02-DECISIONS/0140-the-filter-constrains-what-arrives-from-outside.md), which
+supersedes both 0137 and the first attempt at answering this.
+
 ## Open questions
 
 - Should the forward chain be derived from the network resources the node's modules declare, with the

04-ISSUES/142-the-host-is-the-one-thing-the-mesh-does-not-deliver/00-report.md

@@ -0,0 +1,76 @@
+---
+status: located
+opened: 2026-09-29
+located-in:
+  - mesh-host internal/upgrade
+  - mesh-host cmd/mesh-host
+  - mesh-controller (no build source for the host; no resource delivers it)
+fixed-by:
+amended-design: 03-DESIGN/01-to-be/05-the-node-host.md
+---
+
+# 142 — The host is the one thing the mesh does not deliver
+
+## What was observed
+
+A change to the host was merged and could not reach any machine without a person copying a file.
+
+Checked on the mesh of four machines, 2026-09-29:
+
+- **The host is not a build target.** Asked what had been built for it, the control plane answered
+  `nothing has been built for mesh-host`. A merge on the forge builds every changed module and the
+  control plane itself, because the control plane is a module. The host is not one, and nothing
+  builds it.
+- **No declaration delivers it.** No resource kind names an executable to place on a machine, and
+  nothing on a machine fetches one.
+- **The half that recovers from a bad host exists and is unused.** `internal/upgrade` can report that
+  the executable this process started from has been replaced on disk, and records which version last
+  completed a reconcile so a shell script can roll back a host that will not start. The launcher reads
+  that record and rolls back. But `Replaced()` is called by nothing except its own tests — the
+  recovery is wired and the delivery was never built.
+- **Every machine runs a byte-identical binary, stamped by hand.** All four carry the same size and
+  the same timestamp, from the last time somebody built it on a workstation and copied it out. No
+  package owns the file.
+
+## Why it matters beyond this instance
+
+**The component that implements updating is the one thing not updated.** The mesh's stated shape is
+that a push produces the right builds and they reach the machines running them with nobody asking. It
+is true of every module and of the control plane. It is false for the host, which is what applies all
+of them.
+
+**It is a bootstrap problem being answered by a person.** The host cannot be an ordinary module
+because the host is what applies modules; a module that replaces the thing applying it has to survive
+its own replacement. That is a real difficulty, and the work already done — noticing that the
+executable changed, recording a known-good version, a launcher that rolls back — is the hard half of
+solving it. What is missing is the easy half, and its absence makes the hard half dead code.
+
+**A hand-copied binary has no record anywhere.** Nothing says which version a machine runs, so
+nothing can say a machine is behind, and the mesh's own account of itself — every machine current with
+its source — cannot include the host. Four machines agreeing today is luck, not a property.
+
+**And it silently gates any change that starts in the host.** A change that needs the host to report
+something new cannot be rolled out by merging it: the control plane must wait for a person, and until
+then it either refuses what depends on the new report or renders something wrong. That cost is paid by
+every future change of this shape, and it was paid today.
+
+## Open questions
+
+- How is the host delivered without being applied by itself? A candidate shape: the host is built like
+  anything else, published as an artifact, and the *running* host fetches and stages the next one, then
+  stands aside — which is what `Replaced()` was written for and what the launcher's rollback already
+  covers.
+- **Should this ride the bus, rather than becoming a mechanism of its own?** Everything else that
+  reaches a machine already does: a declaration is sent over it, a report comes back over it, and a
+  build announces what it produced on it, which is how a module's new version reaches the machines
+  running it. A host build announcing itself the same way, consumed by the host already running,
+  would make this the existing mechanism pointed at one more artifact rather than a second way of
+  delivering things. It would also give the machine somewhere to say which host it is running, on the
+  report it already sends.
+- What records which version of the host a machine runs, so "behind" is answerable? Nothing does now.
+- Does the host's version belong in its report, beside the other facts a machine states about itself?
+- Who decides when a machine takes a new host — the mesh, on a build, or an operator per machine as
+  with converging? The rollback path means a bad host costs a reconcile rather than a machine, which
+  argues for the former.
+- Does the same gap apply to the launcher and the units beside the binary, which are also files no
+  declaration names?

04-ISSUES/143-converging-does-not-retire-the-firewall-it-found/00-report.md

@@ -0,0 +1,102 @@
+---
+status: located
+opened: 2026-09-29
+located-in:
+  - mesh-host internal/apply/opening.go (retireFirewall)
+  - mesh-host internal/apply/apply.go (the condition it is called under)
+fixed-by:
+amended-design:
+---
+
+# 143 — Converging a machine does not retire the firewall it found, and says it does
+
+## What was observed
+
+The control-node was converged on 2026-09-29, the first machine with a found firewall to be flipped —
+the two converged before it had none.
+
+The preview said, and the flip repeated:
+
+```
+the found firewall (ufw) is disabled, never flushed: its configuration stays on disk
+...
+sent: the host loads the mesh's filter and disables the firewall it found
+```
+
+The mesh then reported the node `converged`, 372 resources applied, nothing failed. Afterwards, on the
+machine:
+
+```
+systemctl is-enabled ufw   -> enabled
+systemctl is-active  ufw   -> active
+```
+
+*Corrected 2026-09-29, an hour later, from reading the host rather than the declaration.* **The first
+account of this was wrong.** It said the declaration carries no resource that would disable the found
+firewall, and that the sentence was printed by the command with nothing implementing it. The
+declaration indeed carries no such resource — but the mechanism was never meant to be one. It is a
+step in the host's own apply, `retireFirewall`, and it exists, is careful, and is strict: it refuses to
+retire anything until it has read back from the machine that the mesh's own table is loaded, it records
+the forward policies first so a half-done retirement can be retried, and it verifies ufw reports
+inactive afterwards.
+
+What is established is narrower and stranger than "nothing implements it":
+
+- ufw was **active and enabled two minutes after the flip**, and the flip had reported the node
+  converged with 372 resources applied and nothing failed.
+- The machine's own record now reads `disabled_by_mesh: true` — but it was written by a reconcile
+  *after* an operator disabled ufw by hand, roughly fifty minutes later. A reconcile found ufw already
+  inactive, asked it to be inactive, read that back, and recorded that the mesh had done it.
+- So the step did not take effect at the flip, and the machine's record now says it did.
+
+The candidates are named rather than chosen, because the evidence does not separate them: the step is
+called only when the apply had no failures, and a skipped step is silent; the mesh's table is loaded by
+a service in the same apply, so whether it was loaded *at the moment the step asked* is an ordering
+question; and the host's own detail lines do not reach the journal, so what it decided is not
+recoverable after the fact.
+
+## Why it matters beyond this instance
+
+**It is a stated behaviour that does not happen, reported as success** — the fault this repository
+exists to catch, and
+[ADR 0100](../../02-DECISIONS/0100-a-node-in-use-is-adopted-before-it-is-converged.md) states it as
+part of what the flip *is*: "loads the mesh's derived filter in place of its refusal-only table, and
+retires the found firewall by disabling it, never by flushing".
+
+**It could only be found on the first machine that had one.** The two machines converged before this
+had no firewall to retire, so the step had never run, and nothing reported that it had not. That is
+the same shape as [issue 136](../136-a-module-may-name-a-program-the-machine-does-not-have/00-report.md):
+a step that is silent when it does nothing.
+
+**The machine is left doubly filtered, which is not what either firewall describes.** Every base chain
+at a hook runs and a drop in any is final, so the machine now enforces the *intersection* of the mesh's
+derived filter and a rule set left by the system being replaced. Nothing is broken by that today —
+measured from outside, mail, the proxy and git-over-ssh answer and the databases and admin interfaces
+are refused — but the machine's behaviour is described by neither of the two things claiming to
+describe it, and the stale set includes a rule for a broker that no longer exists.
+
+**And returning the node to adopted would be wrong in the other direction.** ADR 0100 says that
+restores the found firewall by enabling it again; enabling something that was never disabled is
+harmless, but the mesh's belief about which firewall is in force has been wrong in both modes.
+
+## Open questions
+
+- Which side owns retiring it — a resource in the declaration, so it is applied and reported like
+  everything else, or the flip as an act? A resource seems right: the flip is otherwise entirely
+  expressed as one, and an act that only the command performs cannot be re-checked on a later
+  reconcile.
+- What should a reconcile do if the found firewall is enabled again by hand, or by a package update?
+  Convergence is a state, so presumably re-disable it and say so.
+- Should the preview say what it *will* do rather than what it does, until a step exists that does it?
+  The wording was read as evidence twice in one session.
+- Is there a check that a sentence the mesh prints corresponds to something that happened? This is the
+  second time in one session that a printed claim and the machine disagreed.
+- **Why did the step not take effect?** It is called only when the apply had no failures, and being
+  skipped is silent. The mesh's table is loaded by a service in the same apply, so whether it was
+  loaded when the step asked is an ordering question — and ADR 0100 makes loading it first a
+  precondition rather than an expectation.
+- **A step that records the mesh as having done what an operator did is worse than the omission.** The
+  record now says the mesh disabled ufw. Nothing distinguishes "we did this" from "we found it already
+  so". Should it?
+- Why do the host's own detail lines not reach the journal? Everything it decided during the flip is
+  unrecoverable, which is why this account has candidates instead of a cause.

04-ISSUES/144-the-predecessors-rules-outlive-the-firewall-it-was-found-as/00-report.md

@@ -0,0 +1,70 @@
+---
+status: located
+opened: 2026-09-29
+located-in:
+  - mesh-host internal/apply/opening.go
+  - mesh-controller cmd/mesh-controller (the converge preview)
+fixed-by:
+amended-design:
+---
+
+# 144 — A predecessor's rules outlive the firewall the mesh found, and the mesh cannot see them
+
+## What was observed
+
+The mesh reports one thing about a machine's existing filtering: `firewall found: ufw`. On the
+control-node, ufw was never what filtered the traffic that mattered.
+
+Measured on 2026-09-29, before the machine was converged:
+
+- ufw filters connections *to the machine*. It does not filter connections to a container's published
+  port, which arrive on the forwarded path where the container runtime accepts them before ufw's
+  forward chains are reached. Around thirty ports were published that way.
+- Every one of the mesh's own forwarded openings, converged through ufw, had matched **zero packets** —
+  fifty rules in that chain, none ever matched, while the chain itself had passed 1.6 million
+  established packets. The restrictions read as applied and were inert.
+- What actually kept those ports off the internet was a chain the predecessor installed in the
+  container runtime's own pre-accept hook, allowing the deliberately public ports and the private
+  ranges and dropping the rest on the outward link. Confirmed from outside: the proxy answered, the
+  container manager did not.
+- That chain exists only in the running kernel. The persisted rule file is the distribution's empty
+  default, and nothing on disk recreates the chain.
+
+After the flip, the mesh's own filter is loaded and does cover the forwarded path, so the machine no
+longer depends on that chain. But **the chain is still there**, and it is now the only thing refusing
+two ports the mesh believes are open: the bus and the registry, which
+[ADR 0100](../../02-DECISIONS/0100-a-node-in-use-is-adopted-before-it-is-converged.md) requires be
+reachable from anywhere so a machine can enrol and pull before it has a private-network address. The
+mesh's rendered filter accepts both from anywhere. From outside, both are refused.
+
+## Why it matters beyond this instance
+
+**"The firewall found" is a kind, and filtering is not all in one place.** The host identifies one
+front-end and reports it. A machine can carry rules from several sources — the front-end's own, the
+container runtime's, an intrusion-prevention chain, and whatever a predecessor installed directly —
+and the mesh's account of what filters the machine names exactly one of them.
+
+**So adoption's central promise was half-true in both directions.** What the mesh converged through
+the found firewall on the forwarded path did nothing at all, and what did the work was invisible to it.
+A machine was reported as filtered by a mechanism that was not filtering.
+
+**And convergence cannot retire what it cannot see.** Even once
+[issue 143](../143-converging-does-not-retire-the-firewall-it-found/00-report.md) is fixed and the found
+firewall is disabled, this chain remains, silently narrowing the machine below what the mesh's own
+filter says. A rule the mesh did not write, cannot list, and will not remove — which today breaks the
+enrolment path the design guarantees.
+
+**The safe direction is not the same as the correct one.** Being more closed than intended broke nothing
+visible, which is exactly why it went unnoticed for as long as the mesh has been on this machine.
+
+## Open questions
+
+- Should the host report every place the machine filters from, rather than one kind — the front-end,
+  the runtime's hooks, and any chain it does not recognise, named so a person can look?
+- What should the mesh do about rules it did not write and does not understand? Reporting them seems
+  right; removing them cannot be, and leaving them silent is what produced this.
+- Does an opening converged through a found firewall need a check that it can actually take effect?
+  Fifty rules matching nothing would have been visible from the counters at any point.
+- Is the bus and the registry being reachable from anywhere still what the mesh wants on a machine that
+  faces the internet? The design says yes, for enrolment. It deserves asking on its own rather than
+  being answered by a leftover.