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Author SHA1 Message Date
jochen 0c2eae07c5 Issue 229: the stale tool list is a connection opened before discovery; the fix is list-changed 2026-10-04 11:01:50 +02:00
jochen f23a71e0d7 Issue 230: a report is also lost when the apply restarts the bus 2026-10-04 11:00:27 +02:00
jochen 9c13c89fa3 Issue 229: new tools never reach an agent's connection, and the console's generic tools are not on it 2026-10-04 11:00:13 +02:00
jochen 2db0ea268d Issue 230: a host that hands over loses its report, and a plan waits for it for ever without saying so 2026-10-04 10:54:35 +02:00
jochen 8d83d94659 Issue 229: a rollout cannot be followed through the mesh's tools 2026-10-04 10:51:45 +02:00
mesh-admin a8ffc2b94b Merge pull request 'Research 025 graduated: ADRs 0203–0205, issue 228, to-be 41 (the shell and the account's environment)' (#351) from feat/the-shell-and-its-environment into main 2026-10-04 08:49:36 +00:00
jochen 1dcbdae1c4 Issue 225 → 228: the number was taken on main while this branch was open 2026-10-04 10:30:46 +02:00
jochen c3ec48f85c To-be 41 WP1: directories made inside a home belong to its account 2026-10-04 10:30:23 +02:00
jochen 72eda923c7 ADR 0205: the vendored theme's measured size 2026-10-04 10:30:23 +02:00
jochen c4fedcdbe3 To-be 41 WP1: a shell that refuses logins need not be listed; giving back is never fatal 2026-10-04 10:30:23 +02:00
jochen 0bf70ee8b4 Graduate research 025: the environment and the shell's contributions
ADR 0203: the account's environment is one module's (seat node-environment);
every module contributes variables and PATH entries, rendered by the
controller as a POSIX file and as environment.d.
ADR 0204: shell code is contributed to the login shell in named slots, and
login-shell becomes the mesh's node-login-shell.
ADR 0205: software the distribution does not package ships as a pinned
archive of the module.
Issue 225: undeclaring a user stops a node applying; the shell is never
given back or checked.
To-be 41 carries the work packages; to-be 38 WP5 points to it.
2026-10-04 10:30:23 +02:00
jochen 947b85af5e Research 025: an environment module holds the account's environment
The operator's proposal: one module, holding a mesh seat node-environment, is
the only writer of the account's environment. It renders contributed variables
and PATH entries as a POSIX file shells source and as environment.d for the
graphical session. The shell's contribution shrinks to shell code; the shell
render-then-service-manager-again positions become options weighed against it.
2026-10-04 10:30:18 +02:00
jochen ac6c306df3 Research 025: how a module plugs into the operator's shell
Opened after the zsh module's rollout (to-be 38 WP5) was stopped: every machine
carries the same predecessor-written startup file, the module's block would
duplicate it and drop lines, nothing installs the prompt, and execute never
reads .zshrc. Weighs how modules contribute environment and shell code, where
the operator's own lines go, ordering, and what a contribution is addressed to.
2026-10-04 10:30:18 +02:00
mesh-admin 96df3ccc88 Merge pull request 'ADR 0201 → 0202, and three issues from the night group 8 shipped' (#350) from issues/the-night-of-group-8 into main 2026-10-04 02:34:32 +00:00
jschoubben bc64c5c187 ADR 0201 → 0202, and three issues from the night it shipped
The derived-value record is renumbered a second time: the key-value-buckets
record took 0201 while this waited to merge, as the bundles record took 0188
before it. Both times free when chosen, taken by the time it landed. cycle.py
caught it; three repositories cite this record, so the number matters.

225 — a provisioner has not been able to read its grant secrets since 01:30,
when a module's own code left its container and the files stayed root's. Four
thousand refusals, each worded as patience, and two consumers unserved. Not
from ADR 0202 or 0189, which landed hours later; dates in the report.

226 — the store's sweep stops at the first reference recorded with an address
and collects nothing. A guard that cannot tell 'I will not ask about this'
from 'it would not answer' stops the wrong amount of work.

227 — the photo app's admin client asks for the port the proxy holds. A module
pinned months behind carries everything its branch gained, the first time
anything makes it move.
2026-10-04 04:33:45 +02:00
mesh-admin be4b5777b8 Merge pull request 'Research 024 and ADR 0201: a module keeps its current state in key-value buckets' (#348) from feat/module-state-on-the-bus into main 2026-10-04 01:43:34 +00:00
mesh-admin d882b3568c Merge pull request 'Group 8: ADR 0201 (a provider declares what it derives, issue 124) and ADR 0189 (the store keeps what the records name, issue 108); issue 202' (#305) from feat/the-store-keeps-what-the-records-name into main 2026-10-04 01:30:47 +00:00
jschoubben a3523617d3 Review before merge: the multi-holder boundary, the window's open race, the sweep's bounds
ADR 0201 gains the boundary found reading it back: a consumer keeping several
holders of a deriving provider is refused, because the two ends have no way
to agree. ADR 0189 gains two consequences — the sweep is bounded because it
runs inside a build, and an apply arriving mid-window reopens it.

That last one is issue 224, recorded rather than fixed: the host's rule for a
stopped container is to replace it, and while-stopped is the first thing that
makes a stopped container intentional. Both candidate fixes are decisions with
their own cost. Nothing is worse than it was; the store has never collected.
2026-10-04 03:27:32 +02:00
jochen 6b4da63261 Research 024: the composed grants, checked against a server once built 2026-10-04 02:50:02 +02:00
jschoubben 0231974226 Rebased onto main: ADR 0188 renumbered to 0201, and issue 202's evidence re-taken
The bundles refactor took 0188 on main while this waited in a pull request,
and the mesh's own code cites that one, so this record moves. Only the number
moved; the decision is the one taken on 2026-10-02, and the record says so.

Issue 202 re-checked against the refactored main: the fault stands, and the
test that surfaced it now fails one step earlier on issue 203's new credential
guard. Proven again past both — mint the credential, compose twice, and all
eight of dnsmasq's resources appear only with the setting set. ADR 0164 is
noted as the decision that answers half of it, and is not built.
2026-10-04 02:44:58 +02:00
jschoubben 92c029d10e ADR 0189: the store keeps what the records name, and a maintenance step holds its writers still
Issue 108: the artifact store has never collected anything. Fifty-three
repositories on the machine that serves everything else, and the only outcome
of leaving it is a full disk reported as somebody else's failure.

The mesh decides what may go — from its own build records, so it never names
a digest it did not put there — and the store reclaims the bytes in a nightly
window with its server held still. Deletion on the one door takes nothing a
push did not already have.

Designs 18 and 20 amended; issue 108 resolved.

Also issue 202, found running the controller's suite: a module whose required
setting nobody set is left out of the machine in silence, and dnsmasq became
that module this morning.
2026-10-04 02:40:25 +02:00
jschoubben 2a60da821d ADR 0188: a provider declares what it derives for each consumer, and the mesh tells both ends
Issue 124: a value the mesh's own rule produced reached neither end as a
statement. The object store's provisioner derived each consumer's bucket in
its own code; all three consumers transcribed the rule into their own
definitions, one of them wrong, and each of the three also named the machine
it happens to run on.

A served value may now name the consumer the mesh is serving. Design 27
amended; issue 124 resolved.
2026-10-04 02:40:06 +02:00
jochen e1b0bbde91 Research 024 and ADR 0201: a module keeps its current state in key-value buckets
Events miss a machine that joins after them and replay history where only the
latest matters. A module now declares state it owns and reads; the controller
creates the buckets, the runtime serves them on the bundle's channel. Designs 32
and 25 amended; grants measured against a running server.
2026-10-04 02:36:59 +02:00
mesh-admin 8ca09c70d6 Merge pull request 'Issues 213 and 223 resolved' (#347) from issues/213-223-resolved into main 2026-10-04 00:19:22 +00:00
jochen db71b83711 Issues 213 and 223 resolved: the controller runs as a process, and genesis hands over to it 2026-10-04 02:19:09 +02:00
mesh-admin 9143d0b7c1 Merge pull request 'ADR 0200: genesis pivots to the controller as a container, and the first push hands it to a process' (#346) from decision/0200-genesis-pivots-to-a-container-and-hands-over into main 2026-10-03 23:41:36 +00:00
jochen 24a51a8e53 ADR 0200: genesis pivots to the controller as a container, and the first push hands it to a process 2026-10-04 01:41:30 +02:00
mesh-admin f0d7f91d90 Merge pull request 'Design 38: WP4c complete' (#345) from design/38-wp4c-complete into main 2026-10-03 23:35:31 +00:00
jochen 8578a06ca8 Design 38: WP4c complete, no module's own code runs in a container 2026-10-04 01:35:16 +02:00
mesh-admin 86083f9c9d Merge pull request 'Issues 215, 221, 222 resolved' (#344) from issues/215-221-222-resolved into main 2026-10-03 23:29:38 +00:00
jochen 63d328147e Issues 215, 221 resolved with live proof; 222 diagnosed and resolved 2026-10-04 01:29:32 +02:00
mesh-admin fead0ea440 Merge pull request 'Issues 219-223 and design 38 WP4c built' (#343) from issues/219-223-and-wp4c into main 2026-10-03 23:14:49 +00:00
jochen df503d1cff Issues 219, 220 resolved, 221 located, 222 and 223 opened; WP4c built and proven 2026-10-04 01:14:44 +02:00
mesh-admin c2fc829822 Merge pull request 'Issues 211, 212, 214, 216, 217 resolved; 215's fix recorded' (#342) from issues/211-217-resolved into main 2026-10-03 22:25:07 +00:00
jochen 8d8e5c9a7e Issues 211, 212, 214, 216, 217 resolved with their proofs; 215's fix recorded 2026-10-04 00:24:53 +02:00
mesh-admin affba60b79 Merge pull request 'Issues 219-221: the builder's ordering gaps' (#341) from issues/219-221-the-builder into main 2026-10-03 22:16:13 +00:00
jochen 9ddbc4c68e Issues 219-221: the builder's ordering gaps seen while rolling out issue 218 2026-10-04 00:16:08 +02:00
mesh-admin a972db91f0 Merge pull request 'Issue 218 resolved: the runtime follows its membership, and a refused subscription is not fatal' (#340) from issues/218-rollout into main 2026-10-03 22:14:10 +00:00
jochen 029698fdc8 Issue 218 resolved: the runtime follows its membership, and a refused subscription is not fatal 2026-10-04 00:14:04 +02:00
mesh-admin 895c2afad1 Merge pull request 'Issue 218: a mesh seat answered by a non-holder (located, fixed in mesh-controller#248)' (#339) from issues/218-a-mesh-seat-answered-by-a-non-holder into main 2026-10-03 21:32:24 +00:00
mesh-admin d362155401 Merge pull request 'Issue 218: a mesh seat is answered by a module on a machine that does not hold it' (#338) from issues/218-a-mesh-seat-answered-by-a-non-holder into main 2026-10-03 21:25:27 +00:00
46 changed files with 2745 additions and 35 deletions
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---
status: graduated
initiated: 2026-10-04
touches: [the bus, what a module declares, the tool runtime, the SDK, the bus grants, 03-DESIGN/01-to-be/25-the-bus-on-nats.md, 03-DESIGN/01-to-be/32-what-a-module-declares.md]
became: [02-DECISIONS/0201-a-module-keeps-its-current-state-in-key-value-buckets-it-declares-and-reaches-through-the-runtime.md, 03-DESIGN/01-to-be/32-what-a-module-declares.md, 03-DESIGN/01-to-be/25-the-bus-on-nats.md]
---
# 024 — State a module keeps on the bus
## What is investigated
A place on the bus where a module's own code keeps **current state** — not history — that every
machine sees, including a machine that joins after the state was written: put, get, delete, list and
watch, reached through the node's runtime the way a bundle already publishes, asks and subscribes
([ADR 0198](../../02-DECISIONS/0198-a-modules-long-running-code-is-launched-by-the-node-runtime-and-reaches-the-bus-through-it.md)).
On NATS that is a key-value bucket. The questions are what a module declares, who creates the
bucket, what the grants are, what the runtime's verbs are, and what may never be stored.
## Why
The mesh carries two kinds of module traffic and a third is missing.
- **Events** land in the EVENTS stream: limits retention, seven days, ten thousand messages per
subject, a durable consumer per consuming module that replays what it missed. Never a secret
([design 32](../../03-DESIGN/01-to-be/32-what-a-module-declares.md) §10).
- **Requests** are core request/reply — tool calls, a bundle's `mesh/ask` — and are kept nowhere.
Neither is *the current value of something*. Two cases from the first module that needs it, the
operator's agent on a machine ([design 36](../../03-DESIGN/01-to-be/36-the-operators-agent-on-a-machine.md)):
1. **An MCP server registered for every machine.** Registering emits an event every machine's copy
of the module consumes. A machine the module is assigned to *after* the registration has no
durable consumer yet — the consumer is created at assignment — so it never hears of it. Wanted
instead: one entry per server, for every machine or for one; every machine reads the whole current
set when it starts and watches for changes; unregistering is a delete; any machine can list it.
2. **Which licence a machine is bound to** ([design 39](../../03-DESIGN/01-to-be/39-the-anthropic-licence-manager.md)).
As events, a machine that was off for a day replays every rotation since and asks for a token
after each. It needs only the latest binding and its generation. The token itself stays on
request/reply and is never stored.
The design already expects this. [Design 25](../../03-DESIGN/01-to-be/25-the-bus-on-nats.md) §1:
"conditions and observed state in key-value buckets that anything may watch".
[Research 017](../017-a-mesh-that-heals-itself/01-the-intended-behaviour.md) wants a provisioner's
"what I applied" and a rotation's step kept in one rather than in memory. Nothing implements it.
## What exists, measured 2026-10-04
| | fact | where |
|---|---|---|
| streams | five kinds of mesh stream: CONTROL (work queue), NODES and ASSIGNMENTS (last per subject), EVENTS (limits: 7 days, 10 000 per subject), one work queue per seat that accepts | the controller's broker streams |
| the state relationship | [design 32](../../03-DESIGN/01-to-be/32-what-a-module-declares.md) §4 already names *state* — 1:1, last per subject — and says it is "declared: the mesh's own". Two streams use it, both written by the controller. No module can declare it | design 32, the controller |
| key-value buckets | none, anywhere | all four code repositories |
| the runtime's bus verbs | `mesh/publish`, `mesh/ask`, `mesh/subscribe`; delivery back to the bundle is `mesh/event` | the runtime's launcher |
| the runtime's principal | one bus user per machine carries every assigned module; its grant is the union of theirs. That one module's code does not act as another is the runtime's to keep: it publishes under the module's own name by construction | the controller's grant composition, the runtime's bus |
| what a bundle is issued | a membership per assignment, last per subject, read directly by the runtime: where it serves, where it emits, what it reaches | ADR 0160 |
| who creates bus objects | the controller only — mesh streams on every raise, a seat's stream at registration, a module's consumer at assignment. No module reaches the JetStream API | design 25 §3 |
### What a key-value bucket needs from a grant, against a real server
Measured against nats-server 2.10 with the Go client the runtime already uses, a bucket created by
an unrestricted user and used by two users holding only the subjects below (`B` is the bucket):
| operation | subject published | writer | reader |
|---|---|---|---|
| bind to the bucket | `$JS.API.STREAM.INFO.KV_B` | yes | yes |
| get | `$JS.API.DIRECT.GET.KV_B.>` | yes | yes |
| put, delete | `$KV.B.>` | yes | **refused** |
| list keys, watch | `$JS.API.CONSUMER.CREATE.KV_B.>` — an ordered, ephemeral consumer | yes | yes |
| stop a watch cleanly | `$JS.API.CONSUMER.DELETE.KV_B.>` | yes | yes |
| answers | its own inbox, which every principal already subscribes | — | — |
*Checked again once built, 2026-10-04:* the grants the controller composes for two machines' runtimes —
one carrying the owner, one only a reader — were loaded into a server as composed, and each operation
was run as each runtime's user. The owner's did all of them; the reader's read, listed and watched,
and its put and delete were refused by the server.
Three things the measurement showed that reading the documentation would not have:
1. **A refused put is not an error to the caller; it is a timeout.** The server reports the
permission violation asynchronously, on the connection, and the client waits out its deadline
for an acknowledgement that never comes. So a runtime that relies on the grant alone tells a
bundle "timed out" for "you may not write this" — it must refuse first, from what the module was
issued, with the reason.
2. **A watch's current values include deletions.** A key deleted earlier arrives among the initial
values as a delete marker, before the end-of-current marker. A bundle asking "what is there now"
must not be handed those.
3. **Without the consumer-delete grant, stopping a watch hangs** until its deadline, and the
ephemeral consumer lingers on the server until it times out by itself.
### Whether the events shape is enough instead
Honestly compared, because a new primitive is a cost:
- **EVENTS cannot be made last-per-subject for some subjects.** Retention is per stream, and
JetStream refuses a second stream overlapping the first (verified and recorded in design 32 §3).
A state subject inside `mesh.mod.*.event.>` keeps EVENTS' seven days: a licence binding unchanged
for a week disappears.
- **A separate last-per-subject stream per module** is possible — it is exactly what a key-value
bucket *is* on the server: a stream with one message per subject, a rollup for purge, and direct
reads. Building it by hand gives up the client's get, list, delete and watch, which are the
operations both cases need, and would be the mesh writing NATS's own key-value layer again.
- **Consumers are the wrong reader.** A durable consumer per reading module is created at
assignment and replays from where it is; state wants "everything current, now, then changes",
which an ordered ephemeral consumer from the last value per subject gives and a durable does not.
So key-value is not a convenience over events; it is the state relationship design 32 already
names, opened to modules.
## Questions, and what this effort proposes
1. **What a manifest says.** `state` names the buckets a module owns, by local name — every
instance of the module may write them and read them. `reads` names another module's bucket as
`<module>.<name>`, read-only. Names only, never a bucket or subject (design 32 §1). A bucket's
options — how many past values it keeps, how long a value lives — are the owner's to declare,
the way a seat declares its own retention (design 32 §3).
2. **Scope.** One bucket per module per name, mesh-wide. A key may carry a machine by the module's
own convention (`all.<server>`, `<machine>.<server>`). A bucket per machine was considered and
not proposed: "list every server for every machine" becomes a walk over buckets, and the grant
could only narrow writes, which nothing asked for — every instance of the owner already writes.
3. **Who creates the bucket.** The controller, from the catalogue, on every raise — a bucket exists
from registration, like a seat's stream, so a reader can watch before the owner is assigned
anywhere. Never a module.
4. **The runtime's verbs.** `mesh/state.get`, `mesh/state.put`, `mesh/state.delete`,
`mesh/state.keys`, `mesh/state.watch`, each naming the bucket as the module named it. A watch
is answered once the current values are on their way, then each change is delivered to the
bundle as a `mesh/state` request it answers — current values first (no deletions among them), an
end-of-current marker, then changes. A child that restarts watches again, as it subscribes
again. The runtime refuses, with the reason, a bucket the module was not issued, and a write to
one it only reads.
5. **Secrets.** None in a bucket, sealed or not: a bucket is a stream (design 32 §10). Sealed values
are plain base64 and cannot be recognised, so the mechanical check is partial and said to be: the
runtime refuses a value carrying a field whose name says it is a credential (`password`,
`secret`, `token`, `authorization`, …), which catches the ordinary mistake and not a determined
one. For the first consumer this has a concrete consequence: an MCP server registered with an
authorisation header keeps that header out of the bucket.
6. **History, lifetime, size.** One value per key unless the owner says more; no expiry unless it
says one; a value at most 256 KiB and a bucket at most 64 MiB, the mesh's caps rather than a
module's. **A bucket outlives its module's assignment** — what a module stored is data, and data
outlives what declared it ([ADR 0030](../../02-DECISIONS/0030-data-outlives-the-mesh-that-declared-it.md));
unassigning is not cleaning up. A bucket whose declaration is gone is reported, never removed.
7. **Events or state.** State (above).
## The work, once decided
1. A decision record, then design 32 (*state* becomes a relationship a module declares) and design
25 (key-value buckets are part of the bus) amended.
2. The controller: the manifest's two words and their registration check; buckets asserted on every
raise; the grants for owners' and readers' runtimes; the buckets issued in each membership.
3. The runtime: the five verbs, the watch delivery, the refusals; tested against a real server.
4. The SDK, TypeScript and Go: a small state surface over the verbs.
5. Proved on a running mesh with one small module, then handed to the operator's agent, whose
registered servers move from events to a bucket.
@@ -0,0 +1,94 @@
---
status: graduated
initiated: 2026-10-04
touches:
- 02-DECISIONS/0174-a-node-varies-a-module-through-settings-and-kept-regions-never-an-edit.md
- 02-DECISIONS/0176-the-login-shell-is-a-node-seat-and-execute-is-its-contract.md
- 02-DECISIONS/0177-a-unit-may-be-user-scoped-and-the-service-manager-is-a-node-seat.md
- 02-DECISIONS/0126-a-module-declares-its-own-seats.md
- 02-DECISIONS/0102-the-mesh-writes-into-a-shared-file-never-over-it.md
- 02-DECISIONS/0182-inside-a-home-the-mesh-owns-what-it-places-and-holds-the-rest-as-found.md
- 02-DECISIONS/0112-a-module-definition-names-no-node-mesh-or-path.md
- 03-DESIGN/01-to-be/27-a-module-requires-the-mesh-resolves.md
- 03-DESIGN/01-to-be/31-a-module-declares-its-fail2ban-jail.md
- 03-DESIGN/01-to-be/37-the-operators-machine.md
- 03-DESIGN/01-to-be/38-building-the-operators-machine.md
- 04-ISSUES/168-a-setting-reaches-every-file-and-contribution/00-report.md
became:
- 02-DECISIONS/0203-the-accounts-environment-is-one-modules-and-every-module-contributes-to-it.md
- 02-DECISIONS/0204-a-module-contributes-shell-code-to-the-login-shell-in-named-slots.md
- 02-DECISIONS/0205-software-the-distribution-does-not-package-ships-as-a-pinned-archive-of-the-module.md
- 03-DESIGN/01-to-be/41-the-shell-and-the-accounts-environment.md
---
# 025 — How a module plugs into the operator's shell
## What is investigated
The shell module writes the mesh's part of the account's shell startup file. But the shell is not the
only module that needs a line there. A prompt theme loads itself from it. A language version manager
sets a variable and sources its loader. A toolchain puts its directory on `PATH`. A desktop module
names the browser. Today all of these sit in one hand-written file, and the shell module as written
carries some of them in its own block and loads others only "if a module placed them". Nothing says
how they get placed.
This effort asks four things:
1. **How a module contributes to the shell**: what it declares, who composes it, and in what order it
lands.
2. **Where the environment lives.** Variables and `PATH` entries are facts about the account, not
lines of one shell's syntax. They should reach every shell (interactive or not), the login shell's
`execute` verb, and programs a graphical session starts.
3. **Where the operator's own lines go,** so that assigning the shell module loses nothing the
machine does today.
4. **Which part of a file the mesh owns.** ADR 0174 calls the kept region the operator's; the host and
to-be 38 implement the inverse (the mesh owns a marked block, and everything outside it is the
operator's). The record this becomes says which.
## Why
Rolling out the shell module (to-be 38 WP5) was stopped on 2026-10-04 after a review of what assigning
it would do. Measured in [01](01-what-the-shell-file-holds-today.md):
- Every machine carries the same predecessor-written startup file, so the module's block would be
appended after its own older copy and everything would run twice.
- The block drops lines the machines rely on today.
- Nothing installs the prompt theme or the plugins the block loads.
- The `execute` verb runs a non-interactive login shell, which never reads the file the block is
written into.
The operator's direction: other modules must be able to plug themselves into the shell; the prompt
becomes its own module; assigning the shell module must lose no functionality; and the environment,
`PATH` above all, needs an answer of its own.
## What it touches
- The manifest. A contribution to the shell is either a new use of the existing `contributes` /
`receives` pair or a new gathered field like `jails` (to-be 31).
- The controller's composition, if the controller assembles the text.
- The `login-shell` seat (ADR 0176): what a holder must do with what is contributed to it, and
whether a module or the mesh declares the seat. Possibly a new seat for the environment, beside it
and beside the service manager's (ADR 0177). Research 023 asks the related question of a seat
naming the files its holder owns.
- ADR 0174's wording of the kept region, and ADR 0182's classification of the paths under a home.
- The zsh module, and the modules this makes possible: an environment module, the prompt, a version
manager, a toolchain.
## Where it stands
The operator proposed a separate **environment module**: one module, holding a mesh seat of its own,
that alone writes the account's environment. It writes a file that shells source and the service
manager's user environment, from the variables and `PATH` entries every other module contributes to
it. That is the starting position for the environment ([02](02-how-a-module-plugs-in.md) §1, option
E6). It leaves the shell's contribution as shell code only (§2), addressed to the `login-shell` seat,
which moves into the mesh's own seat set beside the new `node-environment` (§6).
Graduated on 2026-10-04 with one change from the starting positions: the controller, not the
environment module's own code, renders the environment into the module's files, so that the result
is in the declaration before a machine applies it ([ADR 0203](../../02-DECISIONS/0203-the-accounts-environment-is-one-modules-and-every-module-contributes-to-it.md),
option 6b).
## Documents
- [01 — What the shell file holds today](01-what-the-shell-file-holds-today.md): evidence.
- [02 — How a module plugs in](02-how-a-module-plugs-in.md): the options and the starting position.
@@ -0,0 +1,103 @@
# 01 — What the shell file holds today
Measured 2026-10-04 on the four machines of one installation: two servers and two workstations. All
four have the account's login shell set to zsh, zsh installed from the distribution, and a
predecessor-written startup file. The predecessor is retired, so nothing manages these files any more.
## The startup file is the same everywhere
The account's `~/.zshrc` is **byte-identical on all four machines**: 102 lines, one checksum.
`~/.zshrc.local`, which the last line of `~/.zshrc` sources, comes in **two variants**: one shared by
both servers, and one shared by both workstations. So the "per-machine" part is really a
per-*kind*-of-machine part.
The predecessor produced these from one module with two *flavors*: a prompt flavor and an
autocomplete flavor, each of which swapped in a different local file. Its install hook also:
- cloned the prompt theme and three plugins from their upstream repositories into `~/.zsh/`;
- installed fonts;
- changed the login shell.
On the workstations the theme and plugins are still on disk, left over and now owned by nothing. The
servers have none of them.
## What the 102 lines are
Sorted by who should own each line once the machine is modules:
| Lines today | What they are | Natural owner |
|---|---|---|
| `EDITOR`, `VISUAL`, `XDG_CONFIG_HOME`, `PATH` gaining `~/.local/bin` and two script directories | the account's environment | the shell's default, or the environment itself |
| `PATH` gaining a toolchain's directory | environment, for one tool | the toolchain's module |
| a version manager's directory variable plus sourcing its loader | environment *and* shell code | the version manager's module |
| two variables naming the operator's own script library | environment, the operator's own | the operator |
| a variable that turns off an agent's terminal-title handling | environment, for one tool | the agent's module |
| the terminal title hook, keybindings, `dircolors`, the `ls`/`grep` aliases, `ll`/`la`/`l`, a container-run alias, two disk-usage functions, two port aliases | interactive shell behaviour | the shell's default |
| the prompt's instant-prompt cache, the theme, the prompt's own configuration file | shell code, order-sensitive (instant prompt first) | the prompt module |
| autosuggestions, syntax highlighting (and, unloaded, an autocomplete plugin on disk) | shell code, order-sensitive (syntax highlighting last) | a plugin module, or the prompt module |
| sourcing `~/.zshrc.local` | the operator's hook | the operator |
The workstation variant of the local file adds:
- more environment: a desktop toolkit theme, a file manager's plugin list, `BROWSER`, `VISUAL`
overridden to a graphical editor, a language toolchain's binary directory on `PATH`;
- two pieces of shell code: one that pads the prompt to the bottom of the terminal under a display, and
one that sources a function file another module places;
- a hook sourcing a further per-node file.
The server variant holds only that last module-placed source line.
**Count:** a workstation runs 65 non-comment lines from the two files (53 shared, 12 local); a server
runs 54. Of a workstation's 65:
- about a quarter (15) are environment;
- about half are interactive defaults no other module cares about;
- the remaining quarter is other modules' code and hooks (a prompt, plugins, a version manager, an
agent's functions), loaded from the shell file only because there was nowhere else to put it.
## The shell module as written
The `zsh` module of to-be 38 WP5 (catalogue change, unmerged):
- writes one block, appended at the end of `~/.zshrc`, holding a subset of the shared file:
- its environment lines, minus the toolchain directory, the version manager and the agent variable;
- the title hook, keybindings and the most common aliases, minus the port aliases;
- guarded `source` lines for the theme and two plugins *if present*;
- the source of `~/.zshrc.local`.
- assigned to any of the four machines, appends that block after the identical lines already there, so
every line in it runs twice, `~/.zshrc.local` included.
- on the servers, the guarded prompt lines find nothing; nothing installs the theme anywhere.
## Which startup file reaches what
zsh's startup order, and what each path through it reads:
| started as | reads |
|---|---|
| interactive login (a console, ssh with a terminal) | `.zshenv`, `.zprofile`, `.zshrc`, `.zlogin` |
| interactive non-login (a new terminal window) | `.zshenv`, `.zshrc` |
| non-interactive login: `zsh -lc …`, what the `execute` verb runs | `.zshenv`, `.zprofile`, `.zlogin`, **not** `.zshrc` |
| non-interactive: a script, `ssh host command` | `.zshenv` only |
So an environment written into `.zshrc` reaches neither `execute` nor a script. The distribution's
system-wide login profile, which zsh's system `zprofile` sources, only ever *appends* to `PATH` when an
entry is missing. An entry the account's `.zshenv` puts first therefore survives a login.
A graphical session's programs (a launcher, a bar, a window manager's key bindings) are started from the
display manager and the service manager, not from a shell, and read none of these files. The service
manager's own place for the account's environment is `~/.config/environment.d/`. Today it holds nothing
on any of the four machines, so a program launched from the window manager does not see `PATH` entries
that a terminal does.
## What the mesh already has for "many modules, one file"
Measured over the catalogue's 69 module definitions:
| mechanism | used by | shape |
|---|---|---|
| `contributes` / `receives` | 28 contribute, 15 receive | A consumer contributes **facts** keyed by a requirement. The provider receives all of them as one file in the mesh's own format, and **renders them itself**. "The controller does not know what a reverse proxy is." |
| `listens` / `filtering` | 40 declare listens, 1 composes | The controller derives the whole firewall rule set from every module's ports and writes it where the holder asks. |
| `jails` / `jailing` | 3 declare, 1 composes | Each module supplies its jail **in the tool's own format**. The controller assembles them, sorted, into the one file the holder names. |
| `into: block` on a file | 2 | One module's marked region inside a file something else owns. Text outside the region is kept byte for byte. Placement is at the end, or at the start. |
None of these is a contribution of shell code or of environment today.
@@ -0,0 +1,197 @@
# 02 — How a module plugs in
Six questions, taken one at a time: the environment, shell code, the operator's own lines, order,
who renders, and what a contribution is addressed to. Each has the options weighed and a starting
position. The positions were set with the operator on 2026-10-04 and are what this effort tests, not
what it has decided.
## 1. The environment: variables and `PATH`
A variable or a `PATH` entry is a fact about the account. It holds whichever shell is the login shell,
and it is wanted by:
- every shell, interactive or not;
- the login shell's `execute`;
- a graphical session's programs.
[01](01-what-the-shell-file-holds-today.md) measures that `.zshrc` reaches only the first kind, and
only interactively.
| | option | for | against |
|---|---|---|---|
| E1 | Each module writes lines into the shell's rc file (today) | nothing new | misses `execute`, scripts and the graphical session; written in one shell's syntax, so a second shell module starts over |
| E2 | A module contributes environment facts (a variable and its value; a `PATH` entry and its position) **to the login shell**. The holder renders them into its shell's always-read file (`~/.zshenv` for zsh) | reaches every zsh, `execute` included; a contributor names no path and no shell | the graphical session sees none of it; the environment is tied to which module holds the shell; every shell module reimplements the same rendering |
| E3 | E2, and the service-manager holder (ADR 0177) renders the same facts a second time into `~/.config/environment.d/` | the graphical session sees the same `PATH` as the terminal | one fact set, two owners, two renderings that can disagree; the service manager's module gains a duty unrelated to managing services |
| E4 | One composed file in `environment.d` syntax, sourced by the shell with export-all | one file, two readers | ties the shell to the service manager's syntax, which is close to POSIX assignments but not equal (its `${VAR:-default}` and quoting rules differ); a value with a space breaks one reader or the other |
| E5 | Shells take the environment from the service manager's environment generator, which prints the merged `environment.d` | no file of the shell's at all | every shell depends on the service manager and starts a process on every start; the generator's output is unquoted, so a value with a space breaks it |
| **E6** | **An environment module.** A module of its own (working name `node-env`) holds a mesh seat, `node-environment`, and is the only writer of the account's environment. Every module contributes its variables and `PATH` entries to that seat. The holder writes them in each reader's format: a POSIX file of `export` lines that shells source, and the service manager's `~/.config/environment.d/` | the environment no longer depends on which shell holds `login-shell`; one owner and one rendering per format, both from the same facts; the graphical session included without the service manager's module; a contributor addresses "the environment", never a shell; the `PATH` rules (order, de-duplication) live in one module's code, where a test can hold them | one more module and seat, assigned on every node beside the shell; the `login-shell` protocol gains a duty, to source the environment file, which must be written down and checked |
**Starting position: E6.** It was the operator's proposal on 2026-10-04, and it replaces this
document's first position (E2, then E3).
- The facts are the contribution. Each format is rendered once, by the one module whose subject is the
environment.
- A shell module's part shrinks to one line in its always-read file: `.zshenv` for zsh, sourcing the
environment module's POSIX file. A bash or fish module writes the same line in its own file, and no
contributor changes when the login shell does.
Sketched, for a node with zsh, the environment module, and a toolchain:
```
toolchain ──contributes PATH entry──▶ node-environment ◀──contributes EDITOR, ~/.local/bin── zsh
│ (held by node-env)
┌──────────────────┴──────────────────┐
▼ ▼
POSIX export file ~/.config/environment.d/
▲ ▲
sourced from ~/.zshenv read by the service manager
(every zsh, execute too) (the graphical session)
```
The shell module still contributes its own environment (`EDITOR`, `XDG_CONFIG_HOME`, `~/.local/bin` on
`PATH`) as a contributor like any other; it does not write those lines itself. Once issue 168 closes,
the values a person varies become settings of whichever module contributes them (ADR 0174).
## 2. Shell code: a prompt, plugins, a version manager's loader
This *is* one shell's syntax, and order matters: a prompt's instant-prompt cache must run first, and
syntax highlighting last.
| | option | for | against |
|---|---|---|---|
| S1 | **A contribution of code for one shell** (the shell it is for, the code, a slot), gathered by the controller and placed inside the holder's block in slot order. The same shape as `jails`, which a module supplies in fail2ban's own format and the controller assembles | a contributor names no path; the order is declared and checkable; unassigning the contributor removes its code at the next composition; a node holding fish simply has no zsh code rendered, and the resolver can say so | the controller gains one more gathered field; code for a shell travels in the declaration (in the clear, so no secrets in it, as for any file) |
| S2 | **A drop-in directory**: each module places its own `~/.zsh/rc.d/NN-name.zsh`, and the shell's block sources the directory | no controller change; each file is its module's own, removed when undeclared | every contributor hard-codes a path inside the shell module's territory, against ADR 0112's spirit; order is a naming convention nothing checks; nothing ties the file to the shell actually being zsh |
| S3 | Contributions as facts the holder renders (`contributes`/`receives` proper) | one mechanism with question 1 | code is not a fact; the holder would only paste it, which is S1 with an extra file |
**Starting position: S1.** A contribution to the shell carries **only code**, for named shells, each
piece in a slot. Variables and `PATH` entries never go here; they go to the environment (§1). So a
module touching both makes two contributions:
- A prompt module contributes zsh code in the first slot, and its own configuration file is its own
owned file (ADR 0182).
- A version manager contributes its directory variable to the environment, and its loader as code
for each shell it supports.
- A toolchain contributes a `PATH` entry to the environment and nothing to the shell.
What has to be settled: what each contribution is *addressed to*. Section 6 covers that.
## 3. The operator's own lines: the "local override"
Assigning the shell module must lose nothing the machine does today. That has two halves.
**What is common is the module's default, not an override.** The startup file is identical on all four
machines ([01](01-what-the-shell-file-holds-today.md)). A line every machine has is the shell module's
default, or another module's contribution. It is not a local override that a person would keep in step
on every machine by hand. Most of today's file therefore moves into the shell module's block and into
the contributions above. Little of it stays the operator's.
**What is the operator's is everything outside the mesh's block.** The host already works this way:
- the mesh's region is the marked block;
- text outside it is kept byte for byte, and checked unchanged;
- the region is given back when the module goes.
| | option | for | against |
|---|---|---|---|
| O1 | The mesh's block at the **start** of the file; the operator's lines after it | the operator's lines run last and win, which is what an override means; already supported (`at: start`) | a file the operator later rewrites must keep the markers; the host refuses a broken pair rather than guess |
| O2 | A named operator region *inside* a file the mesh writes whole (ADR 0174's wording) | the file is entirely the mesh's except one hole | the opposite of what the host implements; a file a person already owns becomes the mesh's |
| O3 | Only `~/.zshrc.local`, sourced from the block; `~/.zshrc` the mesh's whole | one obvious place | takes over a file the person owns today; ADR 0182 classifies the shell's own file as *written into*, not owned |
**Starting position: O1.** `~/.zshrc.local` keeps working because the operator's own lines source it,
not because the mesh's block does.
The record this effort becomes corrects ADR 0174's description of the kept region as a **progressive
insight**: the decision stands (a node varies a module by settings or by the operator's own lines,
never by an edit), and only its description of which side is marked changes.
**The one-off migration** is a person's act, listed in the module's documentation (ADR 0182):
- remove from today's file every line the block or a contribution now carries;
- keep the rest below the block.
Until a prompt module and the other contributors exist, the lines they will carry stay among the
operator's own. Nothing is lost at any step.
## 4. Order
Order matters only for code. The environment is set before any code runs, because zsh reads
`.zshenv` first. `PATH` entries carry their own position (before or after the system's), which the
environment module orders, not the shell.
| | option | for | against |
|---|---|---|---|
| R1 | Numbers (`10`, `50`, `90`) | familiar | every contributor guesses a number; collisions are silent |
| R2 | **A few named slots**, `first` / `normal` / `last`, with the module name breaking ties | the prompt says `first` and highlighting says `last` because that is what they mean; the composed result is the same bytes every time | three slots may not be enough |
**Starting position: R2.** Inside the shell module's block, the order is:
1. the line sourcing the environment module's file (in `.zshenv`, so it runs for every zsh; the rest
of this list is `.zshrc`);
2. the `first` slot;
3. the shell module's own defaults;
4. the `normal` slot;
5. the `last` slot.
The operator's lines come after the block, as option O1 says.
## 5. Who renders: the controller or the holder's code
There are two different renderings, and E6 lets them be answered differently.
**The environment** is facts rendered into two fixed formats by the one module whose subject they are.
- The environment module receives the gathered contributions (the `contributes` / `receives` shape:
facts in the mesh's own format, rendered by the receiver).
- Its own code writes the POSIX file and the `environment.d` file whenever what it receives changes.
That is ADR 0182's third class, written by the module's own process, owned by the account,
atomically.
- The controller learns no shell and no service manager. The `PATH` rules (prepend or append,
de-duplicate, keep the system's entries) are ordinary code with ordinary tests.
- To settle: what runs that code when the received file changes. The candidates are a host action
that restarts on the received file, or a subscription through the runtime (ADR 0198).
**Shell code** is not facts. It is text in the shell's own syntax, assembled in slot order, which is
what the controller already does for fail2ban jails: sort the pieces and concatenate them into the
holder's region. The controller assembles; it never interprets the code. This keeps the shell module
bundle-free for its files, and keeps the composed result visible in the declaration before a machine
applies it.
## 6. What a contribution is addressed to
Under E6 there are two addressees: the environment and the login shell.
| | option | for | against |
|---|---|---|---|
| A1 | **Seats**: environment facts to `node-environment`, shell code to `login-shell`. Each seat's protocol says what its holder does with what is contributed to it | a contributor depends on a role ("the environment", "the login shell"), never on zsh or on one module; works the same for any holder | `login-shell` today is declared by the zsh module itself (ADR 0126). A second shell module may only claim it, never declare it, and the seat exists only while zsh's definition is registered |
| A2 | Requirements the modules provide (`contributes` keyed by them, as the reverse proxy is) | an existing mechanism | a contributor on a node without the provider fails to resolve, though a toolchain's `PATH` entry with no environment module is merely unwritten |
**Starting position: A1, both seats in the mesh's own seat set** beside the service manager.
- `node-environment` is new, and is the mesh's from the start.
- `login-shell` moves there from the zsh module's definition. A shell is as universal a role as a
service manager, and a protocol that now carries duties (render the shell code contributed to it,
source the environment file) should not depend on one module's registration.
Research 023 (a seat's protocol naming what its holder owns) is the general form of this: the
environment seat would own the two environment files, and the login-shell seat the shell's
startup-file region. The two efforts should not decide it twice.
## Open questions
- Whether a contribution may be conditional on a capability: the workstation-only environment (a
browser, a toolkit theme) is a desktop module's contribution, which arrives only where that module is
assigned. Measured, this may need nothing new.
- What a node without the environment module does with environment contributions: refuse them at
resolve, or leave them unwritten and say so. The position here is to say so; a missing `PATH` entry
is a visible gap, not a broken machine.
- Whether the operator's own variables (the script-library paths in [01](01-what-the-shell-file-holds-today.md))
are the operator's lines below the shell block, or a kept region of the environment module's file.
The first needs nothing new, but reaches only interactive zsh.
- How the prompt module and a plugin module divide the plugins. Packaging decides it as much as
ownership: the plugins come from upstream repositories, not distribution packages, on these machines.
- Whether the `execute` verb should read the interactive file at all once the environment is in
`.zshenv`. The position here is no: a non-interactive login shell plus the environment is what a
command needs, and the prompt's code should not run for it.
- How a contribution reaches a second shell assigned beside the holder, which to-be 38 WP5 names as the
first follow-up record. Under A1 a non-holder renders nothing, so the question becomes whether a
non-holding shell module may render contributions for interactive use.
@@ -9,6 +9,8 @@ extends: 02-DECISIONS/0011-managed-files-are-generated-never-edited.md
# 174. A node varies a module through settings and kept regions, never through an edit
> **The mechanism changed — 2026-10-04, by [ADR 0204](0204-a-module-contributes-shell-code-to-the-login-shell-in-named-slots.md).** Where this record calls a kept region *a marked block in which the operator's own lines are kept*, read the inverse, which is what the host built: the mesh's region is the marked block, and every line outside it is the operator's, kept byte for byte and given back when the module goes. The decision stands: a node varies a module by settings and by the operator's own lines, never by an edit.
## Context
[ADR 0011](0011-managed-files-are-generated-never-edited.md) says a managed file is derived and an
@@ -9,6 +9,8 @@ extends: 02-DECISIONS/0132-a-seat-carries-the-tools-its-holder-must-serve.md
# 176. The login shell is a node seat held by one shell module, and `execute` is its contract
> **The mechanism changed — 2026-10-04, by [ADR 0204](0204-a-module-contributes-shell-code-to-the-login-shell-in-named-slots.md).** The seat is no longer declared by the shell modules (§1). It is `node-login-shell`, in the mesh's own seat set, which a shell module claims. Its holder also places the shell code other modules contribute, and sources the account's environment ([ADR 0203](0203-the-accounts-environment-is-one-modules-and-every-module-contributes-to-it.md)). What stands: one holder per node, the login shell set by the `user` shape and given back, `execute` as the contract, and any node may call it.
## Context
[ADR 0040](0040-what-a-module-is.md) names the shell as its example of a *shared* seat: bash, zsh
@@ -0,0 +1,141 @@
---
topic: the mesh
status: accepted
date: 2026-10-02
deciders: jochen
reconstructed: false
extends: 02-DECISIONS/0082-the-registry-is-reached-by-name-and-trusted-by-the-overlay.md
---
# 189. The store keeps what the records name, and a maintenance step holds its writers still
## Context
The mesh's artifact store has never collected anything
([issue 108](../04-ISSUES/108-the-registry-has-no-garbage-collection-once-it-has-two-doors/00-report.md)).
Every build pushes another layer set; nothing has ever removed one. The predecessor ran a routine
on a timer — stop the registry, collect, start it — and the conversion carried the settings that
routine depends on without the routine, because the routine was a script beside the module and not
a resource in it. The store now holds fifty-three repositories on the machine that serves
everything else, and the only outcome of leaving it is a full disk reported as somebody else's
failure.
Three things stood in the way, and the issue names all three.
**Nothing in the mesh's vocabulary expresses a maintenance window.** The collector requires every
writer stopped while it runs. A `run-once` step runs *beside* containers, not instead of them, and
a scheduled step is the same container on a cadence. There is no way for a module to say *hold this
container of mine still while this runs*.
**Deletion is not enabled, and the door it would be enabled on has no accounts.** The store is
internal, reached by name over the overlay, trusted because being on that network is the permission
([ADR 0082](0082-the-registry-is-reached-by-name-and-trusted-by-the-overlay.md)). The predecessor
kept deletion behind an authenticated door, which it could, having one.
**Nothing says what may be removed.** The registry's own answer — collect everything no tag names —
is wrong here. The mesh pushes each artifact under one moving tag and pins machines by digest, so
every build but the newest is untagged and some machine may still be running it.
## Decision
**1. Deletion is enabled on the store's one door, and the overlay stays the permission.** The
objection dissolves on inspection: that door **already accepts a push**, and a writer who can push
can replace any tag in the store with anything it likes. Delete takes nothing a push did not
already have, and the machines that can reach the door are the ones the mesh's own filter admits
([ADR 0168](0168-a-converged-machine-is-filtered-by-the-mesh-alone.md)). Putting an authenticated
door in front of deletion while leaving push open would be a lock on the window beside an open
door, and it would cost the thing ADR 0082 bought: a store every machine can reach without a
credential to distribute first.
**2. The mesh deletes what it made and no longer keeps; the store reclaims the bytes.** Two halves,
each doing what only it can.
The **mesh** decides. It does not need to enumerate the store to do it — it has never put anything
there it did not record, so **every digest it could remove is already in its own build records**.
It deletes those manifests through the store's door, by digest, and remembers that it did.
The **store** reclaims. A deleted manifest frees no bytes until the registry's own collector walks
the storage with nothing writing to it, so the module declares that collector as a scheduled step
with the server held still for its duration. Plain collection, not `--delete-untagged`: what the
mesh keeps is still a manifest in the store, so it is still referenced, so its blobs stay — the
dangerous flag is not needed at all once the mesh is the one deciding.
**3. What the mesh keeps, stated as three reasons rather than a number.** A digest is kept because:
- **a definition names it** — every artifact reference in any module's current recorded manifest,
which is what the mesh would hand a machine now. No age limit: this is the floor;
- **the mesh can still go back to it** — every artifact of the **five most recent successful
builds** of each module, so a release that turns out wrong has somewhere to return to;
- **nothing else.** An artifact older than that, which no definition names, is what the store is
carrying for no stated reason.
A digest the mesh did not record making is never touched. That is not a safety margin, it is the
whole rule restated: the mesh removes what it put there and can account for, and the images genesis
pushed before any record existed are exactly what this must not reach
([04-ISSUES/102](../04-ISSUES/102-an-address-recorded-at-genesis-or-build-does-not-follow-the-nodes-ports/00-report.md), F4).
**4. A scheduled step may hold its module's own containers still while it runs** —
`while-stopped`, naming resource ids in the same module. The host stops each, runs the step, and
starts them again **whatever the step did**, including when it failed or the host was interrupted.
Three boundaries:
- **Its own module's containers only.** A module that could quiesce a neighbour could stop the
mesh; a maintenance window is a statement about one service's own insides.
- **Scheduled steps only, not `run-once`.** At apply time the host already has a window: the
declaration is applied in order and a step gates what follows, so a one-time offline migration
says *before* rather than *instead of*. A recurring window is the case order cannot express.
- **Restoring is not conditional.** A step that fails must leave the service running; the whole
risk of this field is a window that never closes.
**5. The sweep runs where the records change — after a build the mesh recorded.** That is the
moment new bytes landed and the moment the keep set moved, and it needs no new timer. The
store's collection runs nightly, because reclaiming is slow and the thing it reclaims is already
unreferenced.
## Consequences
- Disk stops growing without bound on the machine that serves the mesh. That is the whole point
and it has no other way to be true.
- A machine behind by more than five builds of a module, which recreates a container, cannot pull
what it was running. It is already a machine the mesh reports as behind, and the answer is the
one the mesh already gives it: the current declaration. Stated here rather than discovered.
- The store is a little less of a museum. A digest in an old build record may no longer be
fetchable, and the record still says what that build made — the record is history, not an
index of what is on disk. The collected mark is kept beside it so the two can be told apart.
- `while-stopped` is a second thing the host does to a container it did not start this pass. It is
deliberately the narrowest form: the module's own, by id, restored unconditionally.
- The store is briefly unavailable each night, for as long as collection takes. Everything that
pulls from it retries; nothing in the mesh treats a momentary store as a failure
([ADR 0185](0185-a-control-plane-behind-its-seats-row-serves-what-it-can.md)).
- **An apply arriving during the window reopens it**, because the host's rule for a container it
finds stopped is to replace it, and `while-stopped` is the first thing that makes a stopped
container intentional. Found by reading this before it merged, recorded as
[issue 224](../04-ISSUES/224-an-apply-reopens-a-maintenance-window-by-recreating-what-it-held-still/00-report.md)
rather than fixed here: the two candidate fixes — the window takes the apply lock, or the apply
learns which containers are held — are each a decision with its own cost, and neither belongs
inside this record. Nothing is worse than it was; the store has never collected at all.
- **The sweep is bounded**: at most two hundred artifacts and sixty seconds per build, stopping at
the first refusal, because it runs inside somebody's build. What is left over is offered again
next time. The store stops growing from the first sweep; it does not empty in one.
## How this is checked
- The host: a scheduled step with `while-stopped` stops the named containers before the run and
starts them after; it starts them again **when the step fails**; it refuses an id that is not a
container of the same module, its own id, and `while-stopped` on a `run-once` step. Each refusal
is tested for what it says, not only that it says something.
- The controller: given build records and current manifests, the keep set holds every reference a
manifest names and every reference of the five most recent builds per module, and nothing else;
a reference the mesh never recorded is never in the delete set; a delete that answers 404 is
recorded as collected rather than retried forever.
- The sweep is tested against a fake store that records what it was asked to delete, so what is
asserted is the decision and not the registry's behaviour.
- Live: the store's size before and after the first nightly collection, read from the machine.
## References
- [issue 108 — the registry has no garbage collection](../04-ISSUES/108-the-registry-has-no-garbage-collection-once-it-has-two-doors/00-report.md)
- [ADR 0082 — the registry is reached by name and trusted by the overlay](0082-the-registry-is-reached-by-name-and-trusted-by-the-overlay.md)
- [ADR 0053 — a step that runs on a schedule](0053-a-step-that-runs-on-a-schedule.md)
- [ADR 0156 — an artifact is what a build produces, and the store is named for its scope](0156-an-artifact-is-what-a-build-produces-and-the-store-is-named-for-its-scope.md)
- [design 32 — what a module declares](../03-DESIGN/01-to-be/32-what-a-module-declares.md)
@@ -0,0 +1,78 @@
---
topic: building it
status: accepted
date: 2026-10-04
deciders: jochen
reconstructed: false
extends: 02-DECISIONS/0067-genesis-is-a-pivot.md
---
# 200. Genesis pivots to the controller as a container, and the first push hands it to a process
## Context
The controller is Go, compiled to one static binary, and is the last of the mesh's own programs a
machine runs from an image ([issue 213](../04-ISSUES/213-the-controller-is-a-go-program-run-in-a-container/00-report.md)).
[ADR 0188](0188-a-modules-own-code-is-bundles-in-any-language-and-a-tools-bundle-speaks-mcp-to-the-runtime.md)
§1 says a module's own code is bundles, never an image, and §3 that a service bundle is a `process` the
host runs. The handover exists: a process may name the container it `replaces`, and the host removes
that container only after the process has stayed up across two checks; two controllers are safe
together for that moment, the second standing by on the controller's consumers and every plan held by
one lock.
What stands in the way is genesis ([ADR 0067](0067-genesis-is-a-pivot.md)), which
[issue 223](../04-ISSUES/223-a-new-mesh-installs-its-controller-as-a-container/00-report.md) found
assumes an image and a container at every step from its third: it builds the controller's image,
starts a temporary controller from it, publishes it, finds the controller's container in the pivot
declaration, and from then on talks to the controller through it. A process's bundle is fetched from
the artifact store, and genesis raises the artifact store only after the pivot.
## Considered Options
1. **Raise the artifact store before the pivot**, publish the controller's bundle to it, and talk to
the controller from the host's side. Rejected for now: it reorders genesis around a store that is
itself a module the controller deploys, and rewrites the steps that talk to the controller — a
larger change to the one path that is exercised least, to remove a container that exists for
minutes.
2. **Pivot to the controller as a container, as today, and let the first push hand it over to the
process**, through the handover that already exists. Chosen.
3. **Keep the controller a container.** Rejected: it is the exception to ADR 0188 that every other
module's code has now left, and it costs a container runtime on the control machine and a
container recreation in the middle of a plan.
## Decision
**Genesis raises the controller as a container, under the resource the controller's process
`replaces`, and the first declaration the controller composes for its own machine hands it over.**
The container is genesis's own shape, built from the controller's repository, and is recorded on the
control machine exactly as the manifest's `replaces` names it, so the first apply after the pivot
finds a replacement for it and removes it once the process is up. The controller's manifest declares
only the process; the image form exists for genesis alone and is not a second way to run the
controller on a live mesh.
This is the one bounded exception to ADR 0188 §1: a module's own code in an image, for the minutes
between the pivot and the first push, on a mesh being created.
## Consequences
- A new mesh ends where a running one is: the controller a process, no controller container.
- Genesis keeps its steps; what changes is that it no longer reads the controller's container from the
manifest, and that it records the container under the name the handover expects.
- The controller's repository keeps its image build for genesis and the lab.
- The handover is now on genesis's path too: a process that fails to stay up leaves the genesis
container serving, and the apply says so — the same rule as on a live mesh.
## How it is checked
The installer's test raises a mesh whose controller manifest is the process form, and asserts that the
container genesis recorded is exactly what the process `replaces`, so the first apply hands over and
leaves one controller. Live, on the running mesh: after the manifest change is pushed, the control
machine runs the controller as a process and no controller container, and the controller's seat
answers throughout.
## References
- [Issue 213](../04-ISSUES/213-the-controller-is-a-go-program-run-in-a-container/00-report.md),
[issue 223](../04-ISSUES/223-a-new-mesh-installs-its-controller-as-a-container/00-report.md)
- mesh-host#86 (the handover), mesh-controller#252 (two controllers safe together),
mesh-controller#253 (the controller's manifest as a process)
@@ -0,0 +1,106 @@
---
topic: what runs on it
status: accepted
date: 2026-10-04
deciders: jochen
reconstructed: false
extends: 02-DECISIONS/0198-a-modules-long-running-code-is-launched-by-the-node-runtime-and-reaches-the-bus-through-it.md
---
# 201. A module keeps its current state in key-value buckets it declares, and reaches them through the runtime
## Context
A module's code reaches the bus through the node's runtime: it publishes events, subscribes to them
and asks tools ([ADR 0198](0198-a-modules-long-running-code-is-launched-by-the-node-runtime-and-reaches-the-bus-through-it.md)).
Events are kept for a week and replayed to a consumer that was away; requests are kept nowhere. What
neither gives is **the current value of something**, seen by every machine, including one that joins
after it was written. The first module to need it — the operator's agent on a machine — registers MCP
servers for every machine as events, and a machine assigned later never hears of them; and it would
replay a week of licence rotations where it needs only the binding that holds now. Research
[024](../01-RESEARCH/024-state-a-module-keeps-on-the-bus/00-overview.md) measured the alternatives and
the grants against a real server.
[Design 32](../03-DESIGN/01-to-be/32-what-a-module-declares.md) §4 already names *state* as one of the
mesh's relationships — 1:1, last per subject — and reserves it to the mesh's own declarations.
[Design 25](../03-DESIGN/01-to-be/25-the-bus-on-nats.md) §1 expects key-value buckets on the bus.
## Considered Options
1. **Key-value buckets a module declares, created by the controller, reached through the runtime.**
Chosen.
2. **State as events on EVENTS, read last-per-subject.** Rejected: retention is per stream and EVENTS
keeps seven days, so a value unchanged for a week disappears; a second stream over the same subjects
is refused by the server (design 32 §3). And events give no get, list or delete.
3. **A last-per-subject stream per module, written by hand.** Rejected: it is what a key-value bucket
is on the server, without the client's get, list, delete and watch — the mesh writing NATS's
key-value layer again.
4. **State in a module's own files or database, shared by asking a tool.** Rejected for state every
machine must see: a machine joining later has to know whom to ask and poll, and an owner that is
down answers nothing — the property the bus exists to remove.
## Decision
**1. A module declares its state by name.** `state` names the buckets it owns, by local name; every
instance of the module may write and read them. `reads` names another module's bucket as
`<module>.<name>`, read-only. A bucket's options are its owner's: how many past values a key keeps,
and how long a value lives. A manifest names no bucket, stream or subject (design 32 §1).
**2. One bucket per module per name, mesh-wide.** A key may name a machine by the module's own
convention; the mesh does not scope buckets per machine.
**3. The controller creates the buckets, from the catalogue, on every raise** — from registration,
like a seat's stream, so a reader can watch a bucket whose owner is not yet assigned anywhere. A module
never creates one. The runtime's grant on each bucket is the union of what its carried modules may do:
an owner's instances write and read, a reader's read.
**4. Each assignment is issued its buckets in its membership** ([ADR 0160](0160-the-mesh-issues-an-assignments-subjects-and-a-runtime-serves-what-it-is-issued.md)),
by the name the module uses for each and whether it may write. The runtime serves `mesh/state.get`,
`put`, `delete`, `keys` and `watch` on the bundle's channel from that list, and refuses — with the
reason — a bucket the module was not issued and a write to one it only reads. A watch delivers the
current values first, without deletions, then an end-of-current marker, then every change, each as a
`mesh/state` request the bundle answers.
**5. No secret is stored in a bucket, sealed or not.** A bucket is a stream, and design 32 §10 keeps
every secret off streams. A value that needs a secret names it; the secret travels on request/reply.
**6. The mesh caps size; a bucket outlives its module.** One value per key and no expiry unless the
owner says otherwise; at most 256 KiB a value and 64 MiB a bucket. Unassigning a module leaves its
buckets and what is in them ([ADR 0030](0030-data-outlives-the-mesh-that-declared-it.md)); a bucket
whose declaration is gone from the catalogue is reported, never removed by the mesh.
## Consequences
- A machine that joins reads the current state at once, and every machine sees a change as it
happens, with no consumer created per reader and nothing replayed.
- The runtime's channel has a sixth verb family, and the SDKs a small state surface over it — a
contract, which ADR 0039 admits: it changes when the verbs do, rarely, and every module should be
rebuilt when it does.
- What got harder: the runtime must keep each module to its own buckets, because one principal per
machine carries all of them and the server enforces only the union. A write the server refuses
surfaces to a client as a timeout, not a refusal, so the runtime's own refusal is what a module sees.
- The secrets rule is only partly mechanical. Sealed values cannot be recognised; the runtime refuses
a value with a field whose name says it is a credential, which catches the ordinary mistake and not a
determined one. For the operator's agent this means an MCP server's authorisation header stays out of
its bucket.
- Buckets accumulate as modules come and go; that they are reported rather than removed is the price
of not deleting data.
## How it is checked
| Rule | Checked by |
|---|---|
| A manifest's state names are local, and a read names a bucket its owner declares | the catalogue's registration check, per manifest; a catalogue test that every `reads` whose owner is present names a bucket that owner declares |
| Buckets exist for every declared state | the controller's raise asserts them idempotently; its test over a real bus |
| Owners write, readers only read | the composer's test of the grants, per principal kind; the runtime's refusal test over a real bus |
| A watch hands current values first, without deletions, then changes | the runtime's test over a real bus |
| No credential-named field in a value | the runtime's refusal test |
| Live | one module puts on one machine and another machine's watch sees it; a machine assigned afterwards reads it at start |
## References
- Research [024](../01-RESEARCH/024-state-a-module-keeps-on-the-bus/00-overview.md)
- [Design 32](../03-DESIGN/01-to-be/32-what-a-module-declares.md) §4 and §10, [design 25](../03-DESIGN/01-to-be/25-the-bus-on-nats.md) §1 and §3
- [ADR 0030](0030-data-outlives-the-mesh-that-declared-it.md), [ADR 0039](0039-what-the-sdk-holds-and-refuses.md),
[ADR 0160](0160-the-mesh-issues-an-assignments-subjects-and-a-runtime-serves-what-it-is-issued.md),
[ADR 0198](0198-a-modules-long-running-code-is-launched-by-the-node-runtime-and-reaches-the-bus-through-it.md)
@@ -0,0 +1,152 @@
---
topic: the mesh
status: accepted
date: 2026-10-02
deciders: jochen
reconstructed: false
extends: 02-DECISIONS/0048-a-provider-creates-the-credential-the-mesh-minted.md
---
# 202. A provider declares what it derives for each consumer, and the mesh tells both ends
> **Written as 0188 on 2026-10-02, renumbered to 0201, and to 0202 on 2026-10-04.** Twice, for the
> same reason twice: the bundles refactor took 0188 while this waited in a pull request, and the
> key-value-buckets record took 0201 while this waited again. Both times the number was free when
> it was chosen and taken by the time this merged. Only the number moved; the decision is the one
> taken on the 2nd. The check that refuses two records sharing a number is what caught it, both
> times — a number is how a record is cited, and three repositories cite this one.
## Context
An arrangement between a consumer and a provider is delivered entirely by the mesh. Where the
provider is, which port it answers on, what name the consumer must present, where its password
is — each arrives as a fact the consumer reads from its binding, or as `${bound:…}` filled into a
file before the declaration leaves the control plane. The provider invents none of it and hands
none of it back ([ADR 0048](0048-a-provider-creates-the-credential-the-mesh-minted.md)).
One kind of value escapes that. Where the **provider names the resource** — a bucket, a database,
a vhost — the name is derived from the consumer, per consumer, and the mesh has no way to carry
it. `serves` is a literal block in the provider's definition: the same values for every consumer.
A provisioner's contract takes a provision and returns nothing. So a value the mesh's own rule
produced reaches neither end as a statement; it is recomputed at one end and transcribed at the
other.
The object store is the instance ([issue 124](../04-ISSUES/124-a-consumer-cannot-be-told-what-its-provider-derived/00-report.md)).
Its provisioner normalises the login the mesh minted into a bucket name and creates, checks and
removes exactly that; the rule lives in twenty lines of the module's own TypeScript. Its three
consumers each write the answer into their own definition by hand. Two transcribed it correctly;
one named a predecessor's bucket, and would have authenticated successfully and been refused on
every object, which reads like a credential fault and is not one.
Even corrected, the transcriptions are wrong in a second way. Each is `mesh-<node>-<slug>`, so
each **names the machine the module happens to run on today** — a definition stating a fact about
one installation, which [ADR 0155](0155-a-definition-names-no-installation-and-how-that-is-checked.md)
forbids and whose check does not catch because the name is not a domain. Move any of the three to
another machine and its configuration points at a bucket its key cannot open.
The shape is not the object store's. A database provisioner that prefixed names, a queue provider
that scoped vhosts, any provider that derives a resource from who is asking: each forces the
consumer to reproduce somebody else's rule and keep it in agreement by hand.
## Decision
**1. A served value may name the consumer the mesh is serving.** A `serves` block, which is
literal today, may interpolate the mesh's own statement of who the consumer is:
- `${consumer:as}` — the identity the mesh minted for this consumer, exactly as the login it is
told to present ([ADR 0049](0049-a-consumers-identity-fits-the-tightest-backend.md));
- `${consumer:as:dns}` — the same identity written as a DNS label.
Nothing else. **The mesh learns no protocol here; it spells its own name in an alphabet it already
knows.** The identity is the mesh's, minted by the mesh, already capped at twenty characters
because of what an S3 access key accepts; `dns` is that same name with its separator written `-`
instead of `_`, which is the whole of the difference between the mesh's identifier alphabet and
the one buckets, vhosts and hostnames use. A provider that needs a prefix or a suffix writes it
around the placeholder, because a served value is a string.
The rejected alternative is **the provider returning values from provisioning** — the natural
channel, since the provider is what derived them. It is rejected for three reasons, in order of
weight. It inverts the delivery the mesh is built on: a grant would carry data the provider wrote
rather than only data the mesh minted, and [ADR 0048](0048-a-provider-creates-the-credential-the-mesh-minted.md)
removed exactly that second path once already. It makes a consumer's declaration incomplete until
its provider's reconcile loop has run, so a consumer could not be composed before a provider
answered — a bootstrap order the mesh does not have and does not want. And it puts the rule where
nothing can check it: a value that arrives from a running process cannot be refused at resolution,
only discovered wrong later, which is the failure this record exists to end.
**2. The mesh resolves it once, per consumer, and tells both ends from the one resolution.** At the
moment a consumer's declaration is composed, the mesh knows exactly who the consumer is. There, and
only there, the placeholders are filled. The result reaches:
- the **consumer**, as the served facts in its binding file and as `${bound:<provision>:<key>}` in
any file it writes — unchanged mechanisms, carrying one more key;
- the **provider**, as `serves` on that consumer's entry in its contributions file, so the
provisioner is *told* the name rather than recomputing it.
**The provider stops deriving in code and starts declaring.** One statement, filled once, delivered
to both ends: the two cannot disagree, because there is no second computation to disagree with.
**3. A served value stays settled before it is per-consumer.** Settings still compose into `serves`
([ADR 0174](0174-a-node-varies-a-module-through-settings-and-kept-regions-never-an-edit.md)), and the consumer
placeholders are filled after that, so an operator may set a prefix and the mesh still derives the
rest. A `${consumer:…}` naming a fact or an alphabet the mesh does not have is refused when the
definition is parsed, with what it may say.
**4. A consumer may no longer name the resource its provider derives.** With the value delivered,
a literal in a consumer's definition is not merely redundant — it is the one thing that can
disagree with what the provider will actually create. The three object-store consumers lose their
hand-written bucket names in this change.
**5. A consumer that keeps several holders of one provision may not be served a derived value.**
Each holder gets its own login, `…_<local>` ([ADR 0094](0094-a-module-may-hold-several-secrets-from-one-provider.md)),
and a provider derives from the login — so it would make one resource per holder, while the
consumer's side has one binding and one `${bound:<provision>:<key>}`, both derived from the
un-suffixed identity. That is this record's own failure one case to the side, and just as quiet:
the consumer would authenticate and be refused on every object. Refused at resolution, naming
both ends. Lifting it means giving the consumer's side a local dimension, which is a decision and
not an omission.
## Consequences
- One more thing a definition may say, and one less thing a module may be wrong about. The
vocabulary grows by a placeholder; the catalogue loses three literals that named this
installation's control node.
- A provider's naming rule becomes readable in its definition instead of in its source. `minio`'s
`bucketFor` goes; the manifest says `"bucket": "${consumer:as:dns}"` and the provisioner uses
what it is given.
- A provider that already serves consumers keeps serving them: the derived value equals what the
code derived, so no bucket, database or login changes name. This is a change of **who says it**,
not of **what is said**.
- A refusal here fails **that machine's push**, naming the definition, and nothing else. That is
deliberate and is the opposite of a module quietly left out: a definition that transcribes
somebody else's rule is wrong everywhere, not just here, and the loud failure is in front of
whoever can fix it.
- The mesh now holds a rule in another system's alphabet — one rule, `dns`, stated once. A second
alphabet is a decision, not an addition: the cost of each is that the mesh must be right about
somebody else's naming, and that cost is only worth paying where the mesh already mints the name.
## How this is checked
- A served value naming an unknown fact or alphabet is refused at parse, with the list of what it
may say — tested on both halves of the message.
- Resolving a consumer whose provider derives a value puts that value in the consumer's binding
file, in its `${bound:…}` substitutions, and in the provider's contributions entry for that
consumer — one test asserting the three agree, because agreeing is the whole point.
- Two consumers of one provider on one machine get two different derived values, and neither gets
the other's.
- A consumer with several holders of a deriving provider is refused, with both ends named — the
test asserts the refusal, not merely that something failed.
- A catalogue-wide test refuses a consumer definition that writes a literal where its provider
derives: the provider's `serves` names the key, so the catalogue can say which definitions
transcribe one.
- `dns` is checked against the identity the mesh actually mints, not against an invented string:
the test derives an identity with `ConsumerIdentity` and asserts the label it becomes.
## References
- [issue 124 — a consumer cannot be told a value its provider derived for it](../04-ISSUES/124-a-consumer-cannot-be-told-what-its-provider-derived/00-report.md)
- [ADR 0048 — a provider creates the credential the mesh minted, and seals nothing](0048-a-provider-creates-the-credential-the-mesh-minted.md)
- [ADR 0049 — a consumer's identity fits the tightest backend](0049-a-consumers-identity-fits-the-tightest-backend.md)
- [ADR 0174 — a node varies a module through settings and kept regions, never through an edit](0174-a-node-varies-a-module-through-settings-and-kept-regions-never-an-edit.md)
- [ADR 0155 — a definition names no installation, and how that is checked](0155-a-definition-names-no-installation-and-how-that-is-checked.md)
- [design 27 — a module requires, the mesh resolves](../03-DESIGN/01-to-be/27-a-module-requires-the-mesh-resolves.md)
@@ -0,0 +1,131 @@
---
topic: what runs on it
status: accepted
date: 2026-10-04
deciders: jochen
reconstructed: false
extends: 02-DECISIONS/0177-a-unit-may-be-user-scoped-and-the-service-manager-is-a-node-seat.md
---
# 203. The account's environment is one module's, and every module contributes to it
## Context
A variable or a `PATH` entry is a fact about the operator's account. A toolchain needs its directory
on `PATH`, a version manager needs a variable naming its directory, an agent needs a variable that
turns one of its behaviours off, and the shell sets an editor. Today every one of these is a line of
one shell's syntax in one hand-written startup file. [Research 025](../01-RESEARCH/025-how-a-module-plugs-into-the-shell/00-overview.md)
measured on four machines:
- about a quarter of the 65 lines a workstation runs at shell start are environment;
- written into `.zshrc`, that environment reaches only interactive zsh. It misses the login shell's
`execute` verb ([ADR 0176](0176-the-login-shell-is-a-node-seat-and-execute-is-its-contract.md)),
every script, and every program a graphical session starts;
- the service manager's place for the account's environment, `~/.config/environment.d/`, holds
nothing on any machine.
The shell module as first written carried some of these lines in its own block and dropped the rest.
## Considered Options
1. **Each module writes its own lines into the shell's startup file.** Rejected: one shell's syntax,
read by one kind of start, and the same lines rewritten by every shell module.
2. **Contribute the facts to the login shell, whose holder renders them.** Rejected: the environment
then depends on which module holds the shell, every shell module renders the same facts again, and
the graphical session sees nothing.
3. **Option 2, and the service manager's holder renders the same facts a second time** into
`environment.d`. Rejected: one fact set with two owners, whose renderings can disagree, and a
duty for the service manager unrelated to managing services.
4. **One file in `environment.d` syntax, sourced by shells.** Rejected: that syntax is close to
POSIX assignment but not equal, and a value one reader accepts breaks the other.
5. **Shells read the service manager's environment generator.** Rejected: every shell start then
runs a process and depends on the service manager, and the output is unquoted.
6. **A module of its own holds the environment.** One mesh seat, held by one module per node,
whose files are the account's environment. Every module contributes facts to it, and those facts
are written in each reader's format. Chosen. It was the operator's proposal.
Within option 6, two ways to write the files:
- **a. The holder's own code renders what it receives.** This was research 025's starting position.
Rejected: the code needs something to run it whenever a contribution changes, and the result exists
only after a machine has applied and run it.
- **b. The controller renders the facts into the holder's files,** in two named formats, at
composition. Chosen. The result is in the declaration before any machine applies it, nothing has to
trigger anything, and the two formats are standards: POSIX shell assignment and the service
manager's `environment.d`. The controller learns no shell. It writes an assignment in a standard
syntax, as it already writes a fail2ban stanza a module supplied.
## Decision
**1. The environment is a node seat, `node-environment`, in the mesh's own set.** One module per node
holds it, and it is the only writer of the account's environment. The first holder is a module of its
own (working name `node-env`), with no package and no process.
**2. Any module contributes to it with `environment`:**
- **`variables`:** names and values. A name is a POSIX variable name and never `PATH`. A value is
literal; it may use `${machine:…}`, resolved first, and may not contain `$`, a quote, a backslash or
a line break. The only expansion is the mesh's own, so the two formats cannot read one value
differently.
- **`path`:** entries, each placed at the `start` or the `end` of the account's `PATH`.
**3. The holder places the rendered environment with two placeholders** in its own files:
- **`${environment:posix}`** renders lines a POSIX shell sources:
- every variable exported;
- every `PATH` entry added only if missing, so sourcing twice changes nothing.
- **`${environment:systemd}`** renders the same facts as the service manager's user environment, with
the account's existing `PATH` kept between the start and the end entries.
Each rendered line names the module that contributed it, so the file answers *where did this come
from*. Contributions are ordered by module name, and then in the order a module declared them.
**4. The seat's protocol fixes where the POSIX file is:** `~/.config/mesh/environment.sh` under the
account's home. A shell sources that path without knowing which module wrote it. The service
manager's file is `~/.config/environment.d/50-mesh.conf`.
**5. Refused at composition:**
- two modules on one node setting the same variable, both named;
- an environment placeholder in a module that does not claim `node-environment`.
A node with contributions and no holder writes them nowhere. The holder's absence is visible in the
node's assignments, and no contributor is refused for it, because a missing `PATH` entry is a gap, not
a broken machine.
## Consequences
- A shell's part in the environment is one line in its always-read startup file, sourcing the
POSIX file. A second shell module writes the same line in its own syntax, and no contributor
changes when the login shell does.
- The graphical session sees the same `PATH` as the terminal, from the same facts.
- The controller gains one gathered field and two renderers. Both are tested byte for byte, like
the jails a node composes ([to-be 31](../03-DESIGN/01-to-be/31-a-module-declares-its-fail2ban-jail.md)).
- What a person sets for themselves stays theirs: variables of their own sit in their own lines of
their shell's file, read after the mesh's.
- **What got harder:** a value that needs another variable expanded (`$HOME`, `$XDG_CONFIG_HOME`)
must be written with the mesh's own `${machine:…}` facts, or it is refused. Expansion at shell start
is exactly what made one value mean two things in two readers.
- Once [issue 168](../04-ISSUES/168-a-setting-reaches-every-file-and-contribution/00-report.md)
closes, a value a person varies becomes a setting of the module that contributes it
([ADR 0174](0174-a-node-varies-a-module-through-settings-and-kept-regions-never-an-edit.md)).
## How it is checked
| Rule | Checked by |
|---|---|
| Both renderings, byte for byte, from a fixed set of contributions | the controller's environment tests |
| Sourcing the POSIX rendering twice leaves `PATH` unchanged | the same tests, running `sh` over the rendering |
| A variable set by two modules is refused, naming both | the controller's resolve test |
| An environment placeholder outside the holder is refused | the catalogue check, which registration runs |
| A value with `$`, a quote, a backslash or a line break is refused | the manifest's parse test |
| The zsh holder sources the path the seat fixes | the catalogue's zsh test |
## References
- [Research 025](../01-RESEARCH/025-how-a-module-plugs-into-the-shell/00-overview.md)
- [ADR 0174](0174-a-node-varies-a-module-through-settings-and-kept-regions-never-an-edit.md),
[ADR 0176](0176-the-login-shell-is-a-node-seat-and-execute-is-its-contract.md),
[ADR 0177](0177-a-unit-may-be-user-scoped-and-the-service-manager-is-a-node-seat.md),
[ADR 0182](0182-inside-a-home-the-mesh-owns-what-it-places-and-holds-the-rest-as-found.md)
- [To-be 41](../03-DESIGN/01-to-be/41-the-shell-and-the-accounts-environment.md)
@@ -0,0 +1,131 @@
---
topic: what runs on it
status: accepted
date: 2026-10-04
deciders: jochen
reconstructed: false
extends: 02-DECISIONS/0176-the-login-shell-is-a-node-seat-and-execute-is-its-contract.md
---
# 204. A module contributes shell code to the login shell in named slots, and the login shell is the mesh's seat
## Context
Some of what a shell runs at start is code in that shell's own syntax, and it belongs to other
modules:
- a prompt theme loads itself and its configuration;
- plugins load themselves;
- a version manager sources its loader.
Order matters: a prompt's instant-prompt cache must run first, and syntax highlighting last. The
predecessor kept all of this in one file per machine, and installed the theme and plugins by cloning
them in a hook.
[Research 025](../01-RESEARCH/025-how-a-module-plugs-into-the-shell/00-overview.md) measured that file
as byte-identical on four machines. It carries:
- the shell's defaults;
- code belonging to four other pieces of software;
- a handful of the operator's own lines.
Nothing gave the other pieces a way in.
Two further facts bear on the seat itself:
- **The seat is declared by the zsh module** ([ADR 0176](0176-the-login-shell-is-a-node-seat-and-execute-is-its-contract.md)
§1, under [ADR 0126](0126-a-module-declares-its-own-seats.md)). The controller refuses a second
module declaring a seat name, so fish or bash could only ever claim it, and the seat exists only
while zsh's definition is registered.
- **The kept region is the other way round.** [ADR 0174](0174-a-node-varies-a-module-through-settings-and-kept-regions-never-an-edit.md)
describes a kept region as a marked block holding the operator's lines. The host built the inverse:
the mesh's region is the marked block, and every byte outside it is kept, verified unchanged, and
given back when the module goes.
## Considered Options
1. **A drop-in directory** that each module places a file in, and the shell sources. Rejected: every
contributor names a path inside the shell module's territory
([ADR 0112](0112-a-module-definition-names-no-node-mesh-or-path.md)); order becomes a naming
convention nothing checks; and nothing ties the file to the shell actually being the one it is
written for.
2. **Facts the holder renders**, through `contributes` / `receives`. Rejected: code is not a fact,
and the holder would only paste it.
3. **Code contributed for a named shell in a named slot, assembled by the controller into the
holder's file.** This is what the controller already does for fail2ban jails: each module supplies
text in the tool's own format, and the controller sorts and concatenates it into the holder's file
without interpreting it. Chosen.
For order, numbers (`10`, `50`, `90`) were rejected: every contributor guesses one, and collisions are
silent. **Three named slots** were chosen: `first`, `normal`, `last`.
## Decision
**1. `node-login-shell` is a node seat in the mesh's own set,** with the verb `execute`. It replaces
the module-declared `login-shell`. Everything else ADR 0176 decided stands: the holder sets the
account's login shell through the `user` shape, `execute` is the contract, and any node may call it.
A shell module claims the seat; none declares it.
**2. Any module contributes shell code with `shell`:** entries naming the shell they are for (`zsh`,
`bash`, `fish`), the slot, and the code. The controller does not read the code.
**3. The holder places the code with placeholders** in its own files: `${shell:<shell>:<slot>}`. Each
is filled with that shell's code for that slot, from every module on the node:
- ordered by module name;
- each piece preceded by a line naming its module;
- empty when nothing is contributed.
A shell-code placeholder in a module that does not claim `node-login-shell` is refused.
**4. The holder's duties, which are the seat's protocol:**
- Source the account's environment ([ADR 0203](0203-the-accounts-environment-is-one-modules-and-every-module-contributes-to-it.md))
from the startup file every start of that shell reads. For zsh that is `.zshenv`, which a script, a
login and `execute` all read.
- Write its interactive block at the **start** of the interactive startup file, so the operator's own
lines run after the mesh's and win.
- Run `execute` as a non-interactive login shell in the account's home:
- bounded below the runtime's call limit;
- its output bounded;
- its whole process group ended on timeout.
**5. The marked block is the mesh's; everything outside it is the operator's.** This is how ADR 0174's
"kept region" is built. That record keeps its decision and gains a note saying where the mechanism
lives.
## Consequences
- A prompt, a plugin and a version manager are each a module with its own package or archive, its own
configuration file, and a contribution. Assigning one adds its line to the shell, and unassigning it
takes the line away at the next composition.
- Assigning the shell module loses nothing the machine does today:
- what is common to every machine becomes the shell module's default or another module's
contribution;
- what is the operator's stays below the block.
- **The one-off migration is a person's act**, listed in the shell module's documentation
([ADR 0182](0182-inside-a-home-the-mesh-owns-what-it-places-and-holds-the-rest-as-found.md)):
delete the lines the block now carries from the found file.
- `login-shell.execute` becomes `node-login-shell.execute`. Nothing has called it yet; the shell
module was never assigned.
- **What got harder:** a module wanting a line in the shell must say which shell and which slot, and a
module supporting three shells writes its code three times. That is the honest cost of code in
three syntaxes.
## How it is checked
| Rule | Checked by |
|---|---|
| Code lands in its slot, in module order, only for its shell | the controller's shell-contribution tests |
| A shell-code placeholder outside the holder is refused | the catalogue check |
| `node-login-shell` is the mesh's, and no module may declare it | the seat table's tests |
| The zsh block sits at the start, sources the environment from `.zshenv`, and holds the three slots | the catalogue's zsh test |
| `execute` is bounded in time and output and kills its process group | the zsh module's tool tests over real child processes |
## References
- [Research 025](../01-RESEARCH/025-how-a-module-plugs-into-the-shell/00-overview.md)
- [ADR 0174](0174-a-node-varies-a-module-through-settings-and-kept-regions-never-an-edit.md),
[ADR 0176](0176-the-login-shell-is-a-node-seat-and-execute-is-its-contract.md),
[ADR 0203](0203-the-accounts-environment-is-one-modules-and-every-module-contributes-to-it.md),
[to-be 31](../03-DESIGN/01-to-be/31-a-module-declares-its-fail2ban-jail.md)
- [To-be 41](../03-DESIGN/01-to-be/41-the-shell-and-the-accounts-environment.md)
@@ -0,0 +1,69 @@
---
topic: what runs on it
status: accepted
date: 2026-10-04
deciders: jochen
reconstructed: false
---
# 205. Software the distribution does not package ships as a pinned archive of the module's own
## Context
The prompt theme the operator uses is not in the distribution's repositories. Its two plugins and an
autocomplete plugin are. The predecessor installed all four by running `git clone` against their
upstream repositories from an install hook. That way:
- the version on a machine was whatever upstream's default branch held the day the hook ran;
- two machines set up a week apart could differ;
- a machine with no route to upstream failed its install.
The mesh already has a pinned, delivered form for a module's own files: an **archive artifact** built
from a directory of the module's source, delivered by the artifact store, unpacked by the host's
`archive` resource, and pinned by digest. One showcase module uses it.
## Considered Options
1. **Clone from upstream on the machine,** as the predecessor did. Rejected: unpinned, unreproducible,
and it needs upstream reachable from every machine.
2. **Build from the distribution's user repository.** Rejected: the host installs packages from the
distribution's own repositories. A user-repository build is a toolchain on every machine for one
theme.
3. **Vendor a pinned upstream release into the module's directory and ship it as the module's archive
artifact.** Chosen. The release and its version are named in the module, its licence travels with
it, and every machine gets the same bytes from the mesh's own store.
## Decision
**A module whose software the distribution does not package carries a pinned upstream release in its
own source directory and ships it as an archive artifact.**
- The module's documentation names the upstream, the version and the licence.
- The host unpacks it with the `archive` resource into a directory the module owns.
- An upgrade is a change to the module, reviewed like any other.
Software the distribution *does* package is installed as a package; a vendored copy of it is
refused in review.
## Consequences
- The catalogue grows by the size of what it vendors: 1.4 MB for the prompt theme at the pinned
release.
- Upstream's security fixes reach a machine only when somebody updates the module. That is the same
trade every pinned dependency makes, and it is visible: the version is in the module.
- **What got harder:** a vendored program that downloads more at run time, as the prompt theme does
for its git status helper, still fetches that part from upstream on first use. This record pins
what the mesh ships, not what the software fetches for itself. The module's documentation says so.
## How it is checked
| Rule | Checked by |
|---|---|
| The archive is pinned by digest | the host's declaration validation, which refuses an archive without one |
| The upstream, version and licence are named | review of the module's documentation; the module's test asserts the licence file is in the archive |
| Packaged software is not vendored | review |
## References
- [ADR 0204](0204-a-module-contributes-shell-code-to-the-login-shell-in-named-slots.md)
- [To-be 41](../03-DESIGN/01-to-be/41-the-shell-and-the-accounts-environment.md)
+7
View File
@@ -188,7 +188,9 @@ python3 00-META/checks/index.py fail if stale
- **0185** — [A control plane behind its seat's row serves what it can](0185-a-control-plane-behind-its-seats-row-serves-what-it-can.md)
- **0186** — [A ban list never holds a neighbour, and the mesh's own bans are its own wherever they hang](0186-a-ban-list-never-holds-a-neighbour.md)
- **0187** — [A dead tracker is not the machine's failure](0187-a-dead-tracker-is-not-the-machines-failure.md)
- **0189** — [The store keeps what the records name, and a maintenance step holds its writers still](0189-the-store-keeps-what-the-records-name.md)
- **0190** — [A seat's work is shared by its holders, and building is the first such role](0190-a-seats-work-is-shared-by-its-holders-and-building-is-the-first-such-role.md)
- **0202** — [A provider declares what it derives for each consumer, and the mesh tells both ends](0202-a-provider-declares-what-it-derives-for-each-consumer.md)
### Its tiers, from the bottom up
@@ -298,6 +300,10 @@ python3 00-META/checks/index.py fail if stale
- **0195** — [The mesh's tools are found by address, not announced whole](0195-the-meshs-tools-are-found-by-address-not-announced-whole.md)
- **0197** — [Every tool announces itself on the bus, in the NATS services protocol](0197-every-tool-announces-itself-on-the-bus-in-the-nats-services-protocol.md)
- **0198** — [A module's long-running code is launched by the node's runtime, and reaches the bus through it](0198-a-modules-long-running-code-is-launched-by-the-node-runtime-and-reaches-the-bus-through-it.md)
- **0201** — [A module keeps its current state in key-value buckets it declares, and reaches them through the runtime](0201-a-module-keeps-its-current-state-in-key-value-buckets-it-declares-and-reaches-through-the-runtime.md)
- **0203** — [The account's environment is one module's, and every module contributes to it](0203-the-accounts-environment-is-one-modules-and-every-module-contributes-to-it.md)
- **0204** — [A module contributes shell code to the login shell in named slots, and the login shell is the mesh's seat](0204-a-module-contributes-shell-code-to-the-login-shell-in-named-slots.md)
- **0205** — [Software the distribution does not package ships as a pinned archive of the module's own](0205-software-the-distribution-does-not-package-ships-as-a-pinned-archive-of-the-module.md)
### How it is built
@@ -320,6 +326,7 @@ python3 00-META/checks/index.py fail if stale
- **0111** — [A build source is on the mesh's git seat, or it is an external repository](0111-a-build-source-is-on-the-git-seat-or-external.md)
- **0149** — [The live mesh is the test bed](0149-the-live-mesh-is-the-test-bed.md)
- **0174** — [A node varies a module through settings and kept regions, never through an edit](0174-a-node-varies-a-module-through-settings-and-kept-regions-never-an-edit.md)
- **0200** — [Genesis pivots to the controller as a container, and the first push hands it to a process](0200-genesis-pivots-to-the-controller-as-a-container-and-the-first-push-hands-it-to-a-process.md)
### How it is checked
+40 -1
View File
@@ -5,10 +5,11 @@ code:
- mesh-controller cmd/mesh-builder
- mesh-controller internal/builder
- mesh-catalog modules/build-agent
updated: 2026-10-03
updated: 2026-10-04
decisions:
- 02-DECISIONS/0190-a-seats-work-is-shared-by-its-holders-and-building-is-the-first-such-role.md
- 02-DECISIONS/0157-a-build-says-what-it-does-on-the-bus-as-it-happens.md
- 02-DECISIONS/0189-the-store-keeps-what-the-records-name.md
- 02-DECISIONS/0150-a-modules-own-code-runs-as-supervised-processes-under-one-account.md
- 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
@@ -317,6 +318,44 @@ build's lines reach a reader of its subject in order and the stream holds them a
against a real server); the seat verb with an id reads the log (controller test); and, live, a build
after the roll-out read line by line through the console.
## The store keeps what the records name
*2026-10-02 — [ADR 0189](../../02-DECISIONS/0189-the-store-keeps-what-the-records-name.md),
[issue 108](../../04-ISSUES/108-the-registry-has-no-garbage-collection-once-it-has-two-doors/00-report.md).*
Every build pushes another layer set and, until this, nothing ever removed one. The registry's own
answer — collect what no tag names — is wrong for this mesh: each artifact is pushed under one
moving tag and machines are pinned by digest, so every build but the newest is untagged and some
machine may still be running it.
**The mesh decides and the store reclaims.** Deletion is enabled on the store's one door — that
door already accepts a push, and a writer who can push can replace any tag, so delete takes
nothing a push did not already have, and ADR 0082's bargain (a store every machine reaches with no
credential to distribute first) is kept. The mesh then removes what it put there and no longer
keeps, **naming it from its own build records** rather than enumerating the store: it has never
put anything there it did not record, so a digest it did not record making is never named, which
is what keeps the sweep away from the images genesis pushed before any record existed.
An artifact stays for one of two reasons and otherwise goes: a definition the mesh holds names it
(no age limit — this is the floor), or it belongs to one of the five most recent successful builds
of its module (somewhere for a wrong release to return to). The sweep runs after a build the mesh
recorded, which is the moment new bytes landed and the moment the keep set moved; it needs no
timer. Deleting a manifest frees no bytes, so the store's own collector runs nightly as a
scheduled step with the server held still — which is what `while-stopped` exists for
([design 20](20-writing-a-module.md)). Plain collection, not `--delete-untagged`: what the mesh
keeps is still a manifest and so still referenced, and the dangerous flag is not needed once the
mesh is the one deciding.
A machine behind by more than five builds of a module, recreating a container, cannot pull what it
was running. It is already a machine the mesh reports as behind, and the answer is the current
declaration.
*How it is checked:* the keep set, against records, holds what a manifest names and the five most
recent builds and nothing else; a reference the mesh never recorded is never in the delete set; an
image and an archive are asked for at their own endpoints; a store with deletion off names the
remedy rather than the status code; a store that does not have it is recorded collected rather
than retried for ever. Live: the store's size before and after the first nightly collection.
## The builder compiles the languages the mesh is written in
*2026-09-29 —
+26 -1
View File
@@ -5,11 +5,12 @@ code:
- mesh-catalog modules/showcase
- mesh-controller internal/builder
- mesh-sdk src
updated: 2026-09-30
updated: 2026-10-02
decisions:
- 02-DECISIONS/0150-a-modules-own-code-runs-as-supervised-processes-under-one-account.md
- 02-DECISIONS/0099-a-step-that-runs-once-names-what-it-reads.md
- 02-DECISIONS/0053-a-step-that-runs-on-a-schedule.md
- 02-DECISIONS/0189-the-store-keeps-what-the-records-name.md
- 02-DECISIONS/0074-the-wire-is-specified-not-the-types.md
- 02-DECISIONS/0040-what-a-module-is.md
- 02-DECISIONS/0039-what-the-sdk-holds-and-refuses.md
@@ -208,3 +209,27 @@ is recreated with the new fact
([ADR 0099](../../02-DECISIONS/0099-a-step-that-runs-once-names-what-it-reads.md)). *How it is
checked:* the host's unit tests run a step again when its named file changed and not otherwise,
and recreate a container naming a step after the step ran.
## A recurring step may hold its own module's containers still
*Written 2026-10-02, from [ADR 0189](../../02-DECISIONS/0189-the-store-keeps-what-the-records-name.md)
and [issue 108](../../04-ISSUES/108-the-registry-has-no-garbage-collection-once-it-has-two-doors/00-report.md).*
Some work cannot be done underneath a running service: an artifact store's collector walks the
storage and requires every writer stopped. A `run-once` step runs *beside* containers and a
scheduled one is the same container again, so until this a module had no way to say it — and the
mesh inherited a store that has never collected anything, because the predecessor said it with a
shell script and a script beside a module is not a resource in it.
A scheduled step may name `while-stopped`: resource ids of **its own module's** containers, which
the host stops before the run and starts again after it, in the reverse order, **whatever the step
did**. Three boundaries, each refused where it can be seen earliest — its own module's containers
only, because a module that could quiesce a neighbour could stop the mesh; scheduled steps only,
because at apply the declaration is applied in order and a step already gates what follows, so a
one-time offline job says *before* rather than *instead of*; and restoring that is not conditional
on anything, because the only real risk of the field is a window that never closes.
*How it is checked:* the host's unit tests assert stop–run–start in that order, the restart after a
step that **failed**, the reverse order for several containers, and a service left down said
loudly. The controller refuses, from the definition alone, a window with no schedule, one on a
run-once step, one naming a container the module does not declare, and one naming itself.
+23 -2
View File
@@ -7,8 +7,10 @@ code:
- mesh-tools src/broker-amqp.ts (to be replaced)
- mesh-catalog modules/nats (to be written)
- mesh-sdk src (the protocol's NATS binding, step 3)
updated: 2026-10-02
- mesh-tools node-tools/internal/bus (a module's state, ADR 0201)
updated: 2026-10-04
decisions:
- 02-DECISIONS/0201-a-module-keeps-its-current-state-in-key-value-buckets-it-declares-and-reaches-through-the-runtime.md
- 02-DECISIONS/0167-a-membership-carries-what-its-module-receives-and-who-the-mesh-is.md
- 02-DECISIONS/0160-the-mesh-issues-an-assignments-subjects-and-a-runtime-serves-what-it-is-issued.md
- 02-DECISIONS/0157-a-build-says-what-it-does-on-the-bus-as-it-happens.md
@@ -48,6 +50,7 @@ mesh's own state lives, and where what a module may say is decided by what it de
| **events** — a module says something happened | 1:many | delivered to every consumer that declared it; dead-lettered when it cannot be |
| **tools** — a module or a person asks another's tool | request/reply | one answer, from one server, or a timeout |
| **work to a role** — a module submits to a capability without knowing who provides it | job | exactly one holder does it; it queues while nobody does |
| **state** — a module's current value of something, every machine reading it | key-value | the newest per key, kept until replaced or deleted; read whole by a machine that joins later |
The last two rows are the ones worth dwelling on, because they are not messaging in the sense of
carrying bytes from A to B. **A role is addressable**, so a caller names the capability and never
@@ -56,7 +59,8 @@ changing ([ADR 0126](../../02-DECISIONS/0126-a-module-declares-its-own-seats.md)
property of the mesh's architecture that happens to be expressed in subjects.
And more of the mesh lands here as it is built: conditions and observed state in key-value
buckets that anything may watch, the server's own advisories becoming observations like any other
buckets that anything may watch — the first of them a module's own declared state, *2026-10-04*
([ADR 0201](../../02-DECISIONS/0201-a-module-keeps-its-current-state-in-key-value-buckets-it-declares-and-reaches-through-the-runtime.md)) — the server's own advisories becoming observations like any other
([research 017](../../01-RESEARCH/017-a-mesh-that-heals-itself/00-overview.md)), and a person's
client speaking the bus directly rather than through a surface built over it (§7). None of that
is a message being moved; all of it is the bus being the mesh's centre.
@@ -84,8 +88,16 @@ mesh.seat.<seat>.event.<verb> a role's own event (JetStream: EVENT
mesh.seat.<seat>.tool.<verb> a role's tool (core request/reply)
mesh.ask.<node>.<command> the controller's command api (core request/reply)
mesh.assignment.<node>.<module> an assignment's membership (JetStream: ASSIGNMENTS, last-per-subject)
$KV.<module>_<name>.<key> a module's state (JetStream: a key-value bucket per declared name)
```
**Added 2026-10-04** ([ADR 0201](../../02-DECISIONS/0201-a-module-keeps-its-current-state-in-key-value-buckets-it-declares-and-reaches-through-the-runtime.md)):
the last row is outside `mesh.` on purpose. A key-value bucket is NATS's own construct and lives
under NATS's own prefix, which is what lets the server's key-value layer — direct reads, rollups,
delete markers, watches — do the work instead of the mesh writing it again. The bucket is named for
the module and the local name joined by an underscore, which neither may contain, so two modules can
never derive one bucket.
**Revised 2026-10-01** ([ADR 0160](../../02-DECISIONS/0160-the-mesh-issues-an-assignments-subjects-and-a-runtime-serves-what-it-is-issued.md)): the rows above
for a module's and a seat's tools are the shapes the controller *issues*, not rules a runtime carries.
Every assignment is published a membership — what it serves and where, in which queue, its seat verbs,
@@ -155,6 +167,7 @@ Core NATS is at-most-once. Everything the mesh must not lose lives in a JetStrea
| CONTROL | `mesh.control.>` except `alive` (a build's outcome moved to its seat, ADR 0121) | work queue, one consumer (the controller), explicit ack | the store-window guarantee ([ADR 0083](../../02-DECISIONS/0083-one-push-leaves-the-mesh-consistent.md)): the controller `nak`s with a delay while its store is away and the message is redelivered; nothing is dropped |
| NODES | `mesh.node.>` | last per subject | one declaration per node, always the newest |
| EVENTS | `mesh.mod.*.event.>` and `mesh.seat.*.event.>` | limits (age, size), durable consumer per subscribing module | a subscriber that was down catches up; after `max-deliver` attempts the advisory feeds `mesh.events.dead` (its own small stream). *2026-10-01:* a build's whole log is here too, as the build-machine seat's `log.<build id>` events ([ADR 0157](../../02-DECISIONS/0157-a-build-says-what-it-does-on-the-bus-as-it-happens.md)) — one subject per build, a week of retention, read back by `builds --log <id>` with a consumer that is gone when the reading is done |
| `KV_<module>_<name>` | `$KV.<module>_<name>.>` | the newest value per key — as many past values as the owner declared — no age unless the owner declared one; a value at most 256 KiB, a bucket at most 64 MiB | a module's state (ADR 0201): one per name in a manifest's `state`, created from the catalogue on every raise, so it exists before its owner runs anywhere; kept when the module is unassigned, because what it holds is data |
Tool calls and heartbeats stay on core NATS: a lost heartbeat is the next heartbeat; a lost tool
call is a timeout the caller already handles.
@@ -234,6 +247,14 @@ expresses this exactly, per subject, and better than a vhost could:
permissions for each consumed event's subject, its tool subjects, and that same inbox prefix.
Nothing else. A module that tries to publish outside its emits is refused by the server, not by
convention.
- **A module's state** (ADR 0201), for whichever principal carries the module — today the machine's
runtime, whose grant is the union of its modules': binding to the bucket, reading a key directly,
and an ordered consumer for listing and watching, created and deleted on the bucket's own stream
and nothing else's; and, for the owner's instances only, publishing under the bucket's own
`$KV.<bucket>.>`. *Measured 2026-10-04 against a running server:* without the consumer-delete
grant a watch cannot be stopped cleanly, and a write the server refuses reaches the writer as a
timeout rather than a refusal — so the runtime refuses first, from the membership, and the grant
is the second line.
- **The controller's user** owns `mesh.control.>`, `mesh.node.>` and the streams, and may submit work
to the seats the mesh's own flows use — a build, for one (ADR 0121).
**A host's user** may publish its own `mesh.control.<node>.>` and subscribe its own
@@ -2,7 +2,7 @@
layer: to-be
status: in-progress
code: [mesh-controller internal/catalogue]
updated: 2026-09-30
updated: 2026-10-02
decisions:
- 02-DECISIONS/0112-a-module-definition-names-no-node-mesh-or-path.md
- 02-DECISIONS/0155-a-definition-names-no-installation-and-how-that-is-checked.md
@@ -14,6 +14,7 @@ decisions:
- 02-DECISIONS/0084-which-provider-serves-a-consumer.md
- 02-DECISIONS/0046-a-module-configuration-is-its-assignments-not-its-manifest.md
- 02-DECISIONS/0038-the-mesh-assigns-the-port.md
- 02-DECISIONS/0202-a-provider-declares-what-it-derives-for-each-consumer.md
---
# 27 — A module requires, the mesh resolves
@@ -206,6 +207,22 @@ name when nothing sets it. That is the contract half of this design's operator p
the placeholder allows: the definition says which values reach which requirement, and nothing else
does. *How it is checked:* the unit tests named in issue 173, and the plan comparison that closed it.
*A provider says once what it derives for each consumer (2026-10-02,
[ADR 0202](../../02-DECISIONS/0202-a-provider-declares-what-it-derives-for-each-consumer.md),
[issue 124](../../04-ISSUES/124-a-consumer-cannot-be-told-what-its-provider-derived/00-report.md)):*
where a provider **names the resource** it gives each consumer — a bucket, a database, a vhost — the
name is derived per consumer, and a literal `serves` block could not carry it. A served value may
now name the consumer the mesh is serving: `${consumer:as}`, the identity the mesh minted, and
`${consumer:as:dns}`, that same identity written as a DNS label. Nothing else — **the mesh learns no
protocol here; it spells its own name in an alphabet it already knows.** Settings are laid on first,
so an operator may still set a prefix and the mesh derives the rest. The mesh fills it at the one
moment it knows who the consumer is, and the one filled value reaches both ends: the consumer, as
its binding's served facts and as `${bound:<provision>:<key>}` in any file it writes; the provider,
as `derived` on that consumer's entry in its contributions file, so its provisioner is told the name
rather than recomputing it. A consumer that writes the derived value into its own definition instead
of asking for it is refused, naming the placeholder to use. *How it is checked:* the unit tests in
ADR 0202's "how this is checked", each run against the unchanged controller first.
## How a definition reads what was resolved
**One form, naming a requirement and a field of its contract.** A definition that needs the database's
@@ -214,7 +231,9 @@ name in a configuration file writes the same thing: the requirement's name and t
controller fills it at resolution.
This one form replaces the placeholders that exist today, one per mechanism: bound values, secrets,
ports and machine facts.
ports and machine facts. It subsumes the consumer placeholder too — a value a provider derives is
read by the consumer exactly as any other field of the contract is, and `${consumer:…}` is only
how the *provider* states the rule.
**The seat placeholder stays, for the controller alone.** The controller composes its own
declaration and reaches the store and broker it made before any module existed, so it cannot be
@@ -11,8 +11,10 @@ code:
- mesh-host internal/apply/apply.go
- mesh-tools src/main.ts
- mesh-catalog modules/mesh-catalog
updated: 2026-10-02
- mesh-tools node-tools/internal/runtime (a module's state, ADR 0201)
updated: 2026-10-04
decisions:
- 02-DECISIONS/0201-a-module-keeps-its-current-state-in-key-value-buckets-it-declares-and-reaches-through-the-runtime.md
- 02-DECISIONS/0160-the-mesh-issues-an-assignments-subjects-and-a-runtime-serves-what-it-is-issued.md
- 02-DECISIONS/0126-a-module-declares-its-own-seats.md
- 02-DECISIONS/0131-everything-on-the-mesh-speaks-to-the-broker-seat.md
@@ -67,6 +69,8 @@ the catalogue, and the mesh would have hundreds of copies of a decision it made
| `tools: status` | queue-group subscription on `mesh.mod.<module>.tool.status` |
| seat `telegram-sender`, `accepts: send` | work-queue consumer on `mesh.seat.telegram-sender.accept.send` |
| `uses: telegram-sender` | publish on that seat's `accept` subjects, and nothing else |
| `state: servers` | a key-value bucket for the module, created by the controller; its instances write and read it |
| `reads: billing.orders` | read and watch billing's `orders` bucket, and nothing else of it |
**Wildcards, and they are the mesh's rather than a bus's.** *Added 2026-09-27, from
[issue 127](../../04-ISSUES/127-a-module-event-derives-a-subject-nothing-publishes/00-report.md).* A
@@ -221,7 +225,7 @@ service" versus "one worker per machine".
| credential | sealed, per consumer | none | none | none | none |
| reply | — | none | none, or an event later | a report | awaited |
| retention | — | age and size | work queue, explicit ack | **last per subject** | none |
| declared | `provides`/`requires` | `emits`/`consumes` | seat `accepts` / `uses` | the mesh's own | `serves` |
| declared | `provides`/`requires` | `emits`/`consumes` | seat `accepts` / `uses` | the mesh's own; a module's `state` / `reads` | `serves` |
**Job** is the one [ADR 0041](../../02-DECISIONS/0041-events-are-a-relationship.md) had no room
for. Its table has events at 1:many and provisions at 1:1; a module submitting work to a service
@@ -236,6 +240,31 @@ last-per-subject retention, and a node that has seen sequence *n* refuses *n−1
That is the wire-level answer to
[issue 107](../../04-ISSUES/107-a-declaration-carries-no-order/00-report.md).
**A module declares state too.** *Added 2026-10-04,
[ADR 0201](../../02-DECISIONS/0201-a-module-keeps-its-current-state-in-key-value-buckets-it-declares-and-reaches-through-the-runtime.md).*
State was the mesh's alone, and modules had the same need with nowhere to put it: an MCP server
registered for every machine, sent as an event, never reached a machine assigned afterwards — its
consumer did not exist yet when the event passed — and a licence binding sent as events replays a
week of rotations where only the latest matters. So a module names the state it **owns** with
`state`, and another module's it **reads** with `reads: <module>.<name>`. Each is a key-value bucket
the controller creates from the catalogue, mesh-wide, existing from registration so a reader can
watch before the owner runs anywhere ([design 25](25-the-bus-on-nats.md) §3). Every instance of the
owner writes; a reader reads and watches. A key may name a machine by the module's own convention;
the mesh keeps one bucket per name, not one per machine, because "every server, for every machine"
is then one list rather than a walk.
What a module sees is what it named. Its assignment's membership lists its buckets by those names,
with whether it may write, and the runtime answers `get`, `put`, `delete`, `keys` and `watch` for
them on the bundle's channel — refusing, with the reason, a name it was not issued or a write to a
bucket it only reads. A watch hands the current values first, then every change: a bundle that starts
late, or starts again, has the whole of the state before it has any of the news.
The owner says how many past values a key keeps and how long a value lives, as a seat says how long
its backlog survives (§3); the mesh caps a value's size and a bucket's. **A bucket outlives its
module's assignment** — what a module stored is data
([ADR 0030](../../02-DECISIONS/0030-data-outlives-the-mesh-that-declared-it.md)) — and one whose
declaration is gone is reported, never removed by the mesh.
## 5. Seats
A module declares a seat with its protocol, and the mesh enforces one holder at its scope
@@ -454,6 +483,14 @@ sealing key leaks, that stream is an archive rather than a moment. So:
existing discipline — *fetched from it, not carried* — applied to the one payload where carrying
it is worst.
**A key-value bucket is a stream, so the same holds for it.** *Added 2026-10-04,
[ADR 0201](../../02-DECISIONS/0201-a-module-keeps-its-current-state-in-key-value-buckets-it-declares-and-reaches-through-the-runtime.md).*
No secret is put in a module's state, sealed or not: state is exactly what a machine joining a year
later reads in full. A value that needs a secret names it, and the secret travels on request/reply.
Sealed values are plain text to anything inspecting them, so this is checked only partly — the
runtime refuses a value carrying a field whose name says it is a credential, which catches the
ordinary mistake and not a determined one.
**The bootstrap, which is circular and has a precedent.** The vault makes every secret
([ADR 0113](../../02-DECISIONS/0113-the-vault-makes-every-secret.md)), including the bus's own
passwords. The vault is a module, and a module needs a bus account, whose password the vault
@@ -523,3 +560,9 @@ billing existing under that name.
on, and exactly those two are rebuilt.
- **A stale declaration is refused.** A bed: replay sequence *n−1* after *n*, and the node refuses
it rather than applying it.
- **A module reaches only the state it declared.** The composer's test: an owner's runtime may write
its buckets, a reader's may only read, and nothing else is granted; the runtime's test over a real
bus: a name not issued and a reader's write are refused with the reason.
- **State is current at once.** The runtime's test over a real bus: a watch hands the current values
without deletions, then an end-of-current marker, then changes. Live: a machine assigned after a put
reads it at start.
+13 -8
View File
@@ -2,7 +2,7 @@
layer: to-be
status: in-progress
code: [mesh-host, mesh-controller, mesh-tools, mesh-catalog]
updated: 2026-10-02
updated: 2026-10-04
decisions:
- 02-DECISIONS/0173-the-operators-machine-is-the-meshs-and-a-module-is-what-it-declares.md
- 02-DECISIONS/0174-a-node-varies-a-module-through-settings-and-kept-regions-never-an-edit.md
@@ -33,12 +33,16 @@ This is the design [to-be 29](29-a-node-has-operator-accounts.md) §2 called *a
Worked on the first one, a shell. The `zsh` module declares:
- a **package**, `zsh`;
- **files under the home**, owned by the account: the shell's rc file with the module's default
configuration, carrying a kept region for the operator's own lines, and `${setting:…}`
placeholders for the few values a node varies; the account and its home are machine facts the
controller resolves ([ADR 0112](../../02-DECISIONS/0112-a-module-definition-names-no-node-mesh-or-path.md),
to-be 29 §2);
- a **seat declaration**, `login-shell`, node-scoped, with its one verb; and a **claim** on it;
- **files under the home**, owned by the account: the mesh's block at the start of the shell's rc
file with the module's default configuration and the slots other modules' code lands in, the
operator's own lines kept after it, and `${setting:…}` placeholders for the few values a node
varies; the account and its home are machine facts the controller resolves
([ADR 0112](../../02-DECISIONS/0112-a-module-definition-names-no-node-mesh-or-path.md),
to-be 29 §2). Its environment is a contribution to the environment module, not lines of its own
([ADR 0203](../../02-DECISIONS/0203-the-accounts-environment-is-one-modules-and-every-module-contributes-to-it.md),
[ADR 0204](../../02-DECISIONS/0204-a-module-contributes-shell-code-to-the-login-shell-in-named-slots.md),
[to-be 41](41-the-shell-and-the-accounts-environment.md));
- a **claim** on the mesh's node-scoped seat `node-login-shell`, with its one verb;
- a **`user` shape** naming the shell, applied only where the module holds the seat;
- a **tools bundle**, the artifact kind for interpreted code, with `execute` and the module's own
`show-config`.
@@ -80,7 +84,8 @@ root escalates itself.
## 4. The seats of the environment
Decided now: **`login-shell`** (module-declared; zsh, fish, bash; verb `execute`) and
Decided now: **`node-login-shell`** (the mesh's own, ADR 0204; zsh, fish, bash; verb `execute`),
**`node-environment`** (the mesh's own, ADR 0203; the environment module; no verbs) and
**`node-service-manager`** (the mesh's own; systemd; verbs over units in both scopes). The rest
are candidates from [research 018](../../01-RESEARCH/018-the-operators-machine-as-modules/04-the-seats-of-the-environment.md),
one record each when its first holder is written: display server, display session, terminal
@@ -2,7 +2,7 @@
layer: to-be
status: in-progress
code: [mesh-tools, mesh-controller, mesh-host, mesh-catalog]
updated: 2026-10-03
updated: 2026-10-04
decisions:
- 02-DECISIONS/0175-one-tool-runtime-per-node-serves-every-modules-tools-on-the-host-side.md
- 02-DECISIONS/0173-the-operators-machine-is-the-meshs-and-a-module-is-what-it-declares.md
@@ -15,6 +15,7 @@ decisions:
- 02-DECISIONS/0192-a-tools-bundle-declares-what-it-is-given-and-the-runtime-hands-it-to-that-bundle-alone.md
- 02-DECISIONS/0193-every-bundle-the-runtime-serves-is-launched-and-the-runtime-knows-no-language.md
- 02-DECISIONS/0198-a-modules-long-running-code-is-launched-by-the-node-runtime-and-reaches-the-bus-through-it.md
- 02-DECISIONS/0204-a-module-contributes-shell-code-to-the-login-shell-in-named-slots.md
---
# 38. Building the operator's machine
@@ -309,8 +310,34 @@ nextcloud, minio), the two whose clients exist on no system (mongodb, mssql: a d
and last the mesh's own (mesh-catalog, mesh-vault, records, gitea, mailu, audit-logger, lab, and the
three mains).
*Built 2026-10-04.* Thirty-four modules no longer run their own code in a container: the first wave
(mesh-catalog#245), the mesh's own and the media modules (mesh-catalog#248, mesh-media-catalog#13),
with a step run where and as it is declared (mesh-host#85) and a process's words filled like a
container's (mesh-controller#250). **Proven live** on every machine that runs them: each moved
module's tools answer from the node's runtime, the steps run as their oneshot units, and the forge's
merge events reach the build pipeline from the runtime — the merge after the move started its own
plan. **Two corrections the machines taught:** a tool that called a broker's command-line client now
runs it inside the broker's own container, because a host package may be uninstallable on a machine
whose package index is stale (mesh-catalog#249); and a module reading its application's own key reads
it through the application's container, because that directory belongs to the account the application
runs as there, which is not the runtime's (mesh-media-catalog#14). *Completed 2026-10-04:* the last three — mesh-catalog, mongodb and mssql, whose code imports npm
packages of its own — moved once the builder installs a bundle's own dependencies before compiling,
keeping the toolchain's SDK authoritative (mesh-controller#255, mesh-catalog#250). Their database
clients are now drivers inlined into the bundle, not command-line clients fetched by a container; one
more correction the machines taught: a driver reaching its server on loopback must give TLS a host
name, since the runtime's Node refuses an address (mesh-catalog#252). **No module's own code runs in
a container any more;** every module with tools answers from its node's runtime, proven by calling a
tool of each.
## WP5 — The shell, on a server first
*Replaced on 2026-10-04 by [to-be 41](41-the-shell-and-the-accounts-environment.md).* A review before
assigning found that the shell module would duplicate every machine's existing startup file, drop
lines from it, leave the prompt uninstalled, and could not be unassigned
([issue 228](../../04-ISSUES/228-a-login-the-mesh-set-is-never-given-back/00-report.md)). The shell,
its environment, the modules that plug into it, and the host's fix are built and proven there. What
follows is the original plan, kept for the record.
*mesh-catalog #224, already written. Half a day to assign and prove.*
**Order.** Assign `zsh` to one server; push; `login-shell.execute@<server> command="uptime"`
@@ -0,0 +1,238 @@
---
layer: to-be
status: in-progress
code: [mesh-host, mesh-controller, mesh-catalog]
updated: 2026-10-04
decisions:
- 02-DECISIONS/0203-the-accounts-environment-is-one-modules-and-every-module-contributes-to-it.md
- 02-DECISIONS/0204-a-module-contributes-shell-code-to-the-login-shell-in-named-slots.md
- 02-DECISIONS/0205-software-the-distribution-does-not-package-ships-as-a-pinned-archive-of-the-module.md
- 02-DECISIONS/0176-the-login-shell-is-a-node-seat-and-execute-is-its-contract.md
- 02-DECISIONS/0177-a-unit-may-be-user-scoped-and-the-service-manager-is-a-node-seat.md
- 02-DECISIONS/0182-inside-a-home-the-mesh-owns-what-it-places-and-holds-the-rest-as-found.md
---
# 41. The shell and the account's environment
What it takes for the operator's shell to be modules, without a machine losing anything it does
today. This design replaces the shell half of
[to-be 38](38-building-the-operators-machine.md) WP5, and finishes the service-manager module of WP6
short of its user-scoped units. The decisions are [ADR 0203](../../02-DECISIONS/0203-the-accounts-environment-is-one-modules-and-every-module-contributes-to-it.md)
(the environment), [ADR 0204](../../02-DECISIONS/0204-a-module-contributes-shell-code-to-the-login-shell-in-named-slots.md)
(shell code and the seat) and [ADR 0205](../../02-DECISIONS/0205-software-the-distribution-does-not-package-ships-as-a-pinned-archive-of-the-module.md)
(vendored software). The evidence is [research 025](../../01-RESEARCH/025-how-a-module-plugs-into-the-shell/00-overview.md).
## What a node with a shell looks like
```
toolchain, agent, … prompt, plugins, version manager
│ environment │ shell (zsh, slot)
▼ ▼
node-environment ── holds ── node-env node-login-shell ── holds ── zsh
│ │
├─▶ ~/.config/mesh/environment.sh ◀─ sourced from zsh's block in ~/.zshenv
└─▶ ~/.config/environment.d/50-mesh.conf ◀─ read by the account's service manager
│
~/.zshrc: the mesh's block FIRST — defaults and the
three slots — then the operator's own lines, kept
```
**The environment module** (`node-env`) holds `node-environment`. It has no package and no process.
Its two files are written by the host from placeholders the controller fills.
**The shell module** (`zsh`) holds `node-login-shell`. It:
- installs the package;
- sets the login shell through the `user` shape;
- writes two blocks:
- one in `.zshenv`, sourcing the environment;
- one at the start of `.zshrc`, holding the defaults every machine shares today: the title, the
keybindings, the aliases and the two small functions, with the three slots in place;
- contributes its own environment: the editor, the configuration home, and `~/.local/bin` plus the
two script directories on `PATH`;
- serves `execute` and its own `zsh_config`.
**The prompt module** (`powerlevel10k`) ships the theme as a pinned vendored archive, and the prompt's
configuration as its own file in a directory it owns. It contributes the zsh code that loads both.
**Two plugin modules** (`zsh-autosuggestions`, `zsh-syntax-highlighting`) each install their
distribution package and contribute one line. Syntax highlighting goes in the `last` slot, which is
what its upstream asks for.
**What stays the operator's** is everything below the block in `.zshrc`, and `~/.zshrc.local`, which
the operator's lines source as they do today. On every machine today that means:
- the version manager's lines and the toolchain's `PATH` entry, until those modules exist;
- the two variables naming the operator's own script library;
- the agent's title variable;
- the port aliases;
- the workstation's desktop variables, which live in `~/.zshrc.local` already.
Nothing is lost at any step, because a line moves out of the operator's part only when a module
carries it.
**The migration is a person's act**, listed in the zsh module's documentation (ADR 0182): after the
first push, delete from `.zshrc` the lines the block now carries. Until then they run twice, which is
harmless and visible.
## Work packages
```
WP1 the host gives a login back (mesh-host) issue 228
WP2 the controller composes environment and shell code (mesh-controller)
WP3 the modules (mesh-catalog) needs WP2 to resolve
WP4 the service manager's module, finished (mesh-catalog) independent
WP5 assign and prove (operator-gated) needs WP1–WP3 merged and rolled
```
WP1, WP2 and WP4 are independent, and are built in parallel on one feature branch per repository
([playbook 07](../../00-META/process/07-feature-branches.md)). WP3 is written in parallel and proven
against WP2's controller before anything is published.
## WP1 — The host gives a login back
*mesh-host. Half a day. [Issue 228](../../04-ISSUES/228-a-login-the-mesh-set-is-never-given-back/00-report.md).*
**What changes.**
- The `user` shape records, in its applied record, the login shell it found whenever it changes it.
- Removing a `user` never deletes the account, whether or not the mesh created it. If the account's
shell is still the one the mesh set, and the recorded shell is still executable, the recorded shell
is set back. Otherwise the shell is left as it is, and the outcome says why.
- Before a shell is set, it is refused unless it is executable and listed among the machine's shells.
The exception is a shell that refuses logins (`nologin`, `false`): the distribution does not list
those, and the controller's own account uses one, so it need only be executable. The refusal fails
that resource and leaves the account untouched.
- A directory the host creates on the way to a file, a block or an archive inside an account's home
belongs to that account, the home itself included when the host makes it. A directory that was
already there keeps its owner and mode (ADR 0182). Until this, a fresh account's `~/.config` or
`~/.local/share` would have been created as root's.
- Giving the shell back is reported, never fatal. A failed `usermod` on removal is named in the
outcome and the record is dropped, because a fatal removal is exactly the wedge issue 228 is about.
**Proof.** The host's tests:
- an undeclared `user` no longer stops the apply;
- the found shell comes back;
- a shell changed by a person since is left alone;
- a missing shell is refused before `usermod` runs;
- a created account survives its removal.
## WP2 — The controller composes environment and shell code
*mesh-controller. One to two days.*
**What changes.**
- **The seat table.** It gains `node-environment` (node scope, no verbs) and `node-login-shell`
(node scope, the verb `execute`). A module may no longer declare a seat named `login-shell` or
`node-login-shell`. Both new seats are seeded into a live store by the existing additive seeding.
- **The manifest.** It gains two contribution fields, each refused at parse when malformed:
- `environment`, with `variables` and `path`: a variable name must be a POSIX name and not `PATH`;
a value may not contain `$`, a quote, a backslash or a line break; a path entry's place is
`start` or `end`;
- `shell`: each entry names a known shell, a known slot, and non-empty code.
- **Composition.** It fills `${environment:posix}`, `${environment:systemd}` and
`${shell:<shell>:<slot>}` in the claiming holder's file contents, from every module assigned to
the node. The rendering is ADR 0203's and ADR 0204's: module order, a naming line per contribution,
`PATH` entries added only when missing. `${machine:…}` in a contributed value is resolved first.
- **Refusals.** A variable set by two modules on one node is refused, naming both. A placeholder in a
module that does not claim the matching seat is refused, both at the catalogue check and at
composition.
**Proof.** The controller's tests:
- both environment renderings, byte for byte, from a fixed set of contributions;
- the POSIX rendering sourced twice by `sh` leaves `PATH` unchanged;
- slot order and per-shell filtering;
- each refusal, by name;
- the seat table carries both seats and refuses a module declaring either.
The catalogue check over the whole catalogue passes.
## WP3 — The modules
*mesh-catalog. One day.*
**What changes.**
- **`node-env`, new.** It claims `node-environment` and declares two owned files: the POSIX file at
the path the seat fixes, and the service manager's file, each holding its placeholder. It declares
no tools.
- **`zsh`, rewritten.**
- It drops its seat declaration and claims `node-login-shell`.
- Its environment moves to a contribution.
- It writes a `.zshenv` block that sources the environment file.
- Its `.zshrc` block goes at the start and carries today's shared defaults, with the three slots.
- It keeps the `user` shape.
- `execute` runs `zsh -lc` in the account's home, with the runtime's session words for the user
manager. Its timeout is bounded below the runtime's thirty-second call limit; its output is cut at
a bound and marked as cut; on timeout it kills the process group.
- Tests cover the tool over real child processes and the manifest's shape.
- Its documentation lists the one-off migration.
- **`powerlevel10k`, new.**
- The theme is vendored at a pinned upstream release, with its licence, as an archive artifact
unpacked into the module's directory under the account's home.
- The prompt configuration is today's file, as its own owned file in the same directory.
- It contributes the zsh code that loads the theme and the configuration.
- Today's file has the instant-prompt cache commented out, so the module does not turn it on.
- **`zsh-autosuggestions` and `zsh-syntax-highlighting`, new.** Each declares its package and
contributes its loader from the distribution's path, in the `normal` and `last` slots.
**Proof.** The controller's catalogue check over the whole catalogue passes. The modules' tests pass.
A rehearsal composition for a node holding all five shows:
- the `.zshrc` block with the prompt in `normal` and highlighting in `last`;
- the environment file with the shell's `PATH` entries;
- the service manager's file.
## WP4 — The service manager's module, finished
*mesh-catalog. Half a day. From the review of 2026-10-04.*
**What changes.**
- System-scope `start`, `stop`, `restart`, `enable` and `disable` escalate with `sudo -n` when the
runtime is not root, as the packet filter and intrusion modules do. They name a refusal by how it
failed.
- User scope reaches the account's manager by its runtime directory, which the runtime's environment
lacks.
- A failed `systemctl` is an error, not an empty list.
- The package resource goes: the service manager is always present, and it collided with the network
module's identical declaration on a machine running both.
- `status` says whether the mesh declares the unit. The restore note is attached only to such a unit.
- Tests cover a fake runner.
The user-scoped units of mesh-host #72 stay to-be 38's WP6.
**Proof.** The module's tests. Live, after WP5:
- `node-service-manager.units` answers in both scopes on a workstation and on a server;
- `restart` of a harmless unit answers `ok`.
## WP5 — Assign and prove
*Operator-gated. Nothing here runs without the operator's go-ahead.*
**Order.**
1. Merge WP1 and roll the host.
2. Merge WP2, and push the controller.
3. Merge WP3 and WP4, and build the new modules by hand: a new catalogue module's first build is asked
for, not automatic.
4. On one server, assign `node-env`, `zsh`, `zsh-autosuggestions` and `zsh-syntax-highlighting`, and
push. Then check:
- `node-login-shell.execute@<server> command="echo $PATH"` shows the shell's entries;
- `.zshrc` begins with the block;
- the operator's lines follow untouched;
- the environment file and the service manager's file exist.
5. The operator deletes the duplicated lines, per the zsh module's documentation.
6. The other server, then the two workstations, the workstations also with `powerlevel10k`.
7. Assign `systemd` everywhere, and prove WP4.
8. Unassign one plugin module on one machine. Its line leaves the block at the next push, and nothing
else changes.
The follow-up records to-be 38 names are still owed:
- what a shell module assigned beside the holder does;
- how a person's own environment variable is a setting rather than a line, once issue 168 closes.
+1
View File
@@ -43,6 +43,7 @@ document is written and this one's status becomes `implemented`.
| [`32-what-a-module-declares.md`](32-what-a-module-declares.md) | **Proposed.** What a module declares and what the bus derives from it: three namespaces, subjects from local names, queues never declared, the five relationships, and the build-publish-deploy lifecycle on one bus | [ADR 0126](../../02-DECISIONS/0126-a-module-declares-its-own-seats.md), [ADR 0127](../../02-DECISIONS/0127-amqp-is-a-provision-not-the-bus.md), superseded by [ADR 0131](../../02-DECISIONS/0131-everything-on-the-mesh-speaks-to-the-broker-seat.md) (superseding [ADR 0125](../../02-DECISIONS/0125-the-bus-is-the-only-broker.md)), [ADR 0041](../../02-DECISIONS/0041-events-are-a-relationship.md) |
| [`37-the-operators-machine.md`](37-the-operators-machine.md) | **In progress.** Every configurable thing on a node is a module, the home included; one default per module varied by settings or kept regions; roles a machine has once as seats with tool contracts; one tool runtime per node on the host side | [ADR 0173](../../02-DECISIONS/0173-the-operators-machine-is-the-meshs-and-a-module-is-what-it-declares.md), [0174](../../02-DECISIONS/0174-a-node-varies-a-module-through-settings-and-kept-regions-never-an-edit.md), [0175](../../02-DECISIONS/0175-one-tool-runtime-per-node-serves-every-modules-tools-on-the-host-side.md), [0176](../../02-DECISIONS/0176-the-login-shell-is-a-node-seat-and-execute-is-its-contract.md), [0177](../../02-DECISIONS/0177-a-unit-may-be-user-scoped-and-the-service-manager-is-a-node-seat.md) |
| [`38-building-the-operators-machine.md`](38-building-the-operators-machine.md) | **In progress.** The work of design 37 as packages: the runtime serves many modules, the controller composes one per node, the console becomes its serving mode, the packet filter moves first, then the shell and the service manager — tested on the live mesh by the operator's decision | [ADR 0175](../../02-DECISIONS/0175-one-tool-runtime-per-node-serves-every-modules-tools-on-the-host-side.md), [0160](../../02-DECISIONS/0160-the-mesh-issues-an-assignments-subjects-and-a-runtime-serves-what-it-is-issued.md), [0149](../../02-DECISIONS/0149-the-live-mesh-is-the-test-bed.md) |
| [`41-the-shell-and-the-accounts-environment.md`](41-the-shell-and-the-accounts-environment.md) | **In progress.** The shell and the account's environment as modules: an environment module every module contributes variables and `PATH` entries to, shell code contributed to the login shell in named slots, the prompt and plugins as modules, the host giving a login back, and the service manager's module finished | [ADR 0203](../../02-DECISIONS/0203-the-accounts-environment-is-one-modules-and-every-module-contributes-to-it.md), [ADR 0204](../../02-DECISIONS/0204-a-module-contributes-shell-code-to-the-login-shell-in-named-slots.md), [ADR 0205](../../02-DECISIONS/0205-software-the-distribution-does-not-package-ships-as-a-pinned-archive-of-the-module.md) |
## Not yet written
@@ -1,9 +1,9 @@
---
status: open
status: resolved
opened: 2026-09-23
located-in: []
fixed-by:
amended-design:
located-in: [mesh-controller internal/inventory, mesh-controller internal/artifacts, mesh-host internal/apply, mesh-catalog modules/distribution]
fixed-by: 02-DECISIONS/0189-the-store-keeps-what-the-records-name.md
amended-design: 03-DESIGN/01-to-be/18-building-a-module.md
---
# 108 — The registry has no garbage collection, and two doors make it harder to add
@@ -75,3 +75,32 @@ real thing services need, and the mesh cannot express one.
images by digest and moves by version — is retention "the digests no recorded build names"?
- Who owns the routine when the store and its public door are two modules — the store, since the
volume is its?
## Answered, 2026-10-02 — [ADR 0189](../../02-DECISIONS/0189-the-store-keeps-what-the-records-name.md)
The three open questions, answered:
- **A maintenance step, or a backend that does not need its writers stopped?** The step. A
scheduled container may name `while-stopped` — resource ids of **its own module's** containers,
which the host stops before the run and starts again after it whatever the step did. A storage
backend the mesh does not run would be a bigger thing to own than the mechanism it avoids, and
the mechanism is wanted anyway: a service that cannot have work done underneath it is a real
shape and the mesh could not express it at all.
- **Is retention "the digests no recorded build names"?** Nearly. An artifact stays because a
definition the mesh holds names it (no age limit), or because it belongs to one of the five most
recent successful builds of its module. Last-N-tags was the predecessor's rule for a registry
that knew nothing else; this mesh knows what each digest is for.
- **Who owns the routine now the second door is gone?** Both halves, each where it can be. The
**mesh** decides what may go — only it holds the records — and asks the store to drop it. The
**store** reclaims the bytes, because only it can stop its own server. Neither half can be done
by the other.
And the sharpened point — enabling deletion on a door with no accounts — dissolved on inspection:
**that door already accepts a push**, so a writer who can reach it can already replace any tag.
Delete takes nothing a push did not have. What it does not do is undo ADR 0082's bargain, which
putting an authenticated door in front of deletion would have.
The second registry process is not built, as the 2026-09-26 note says, so the shared blob cache
and the deletion-cached-by-the-other-door problem never arise. Plain `garbage-collect` is enough:
what the mesh keeps is still a manifest in the store, so `--delete-untagged` — the flag that would
delete images machines are running — is not needed at all.
@@ -1,9 +1,9 @@
---
status: located
status: resolved
opened: 2026-09-26
located-in: [mesh-controller internal/catalogue/declaration.go, mesh-sdk src/provisioner, mesh-catalog modules/minio]
fixed-by:
amended-design:
located-in: [mesh-controller internal/catalogue, mesh-sdk src/provisioner, mesh-catalog modules/minio]
fixed-by: 02-DECISIONS/0202-a-provider-declares-what-it-derives-for-each-consumer.md
amended-design: 03-DESIGN/01-to-be/27-a-module-requires-the-mesh-resolves.md
---
# 124 — A consumer cannot be told a value its provider derived for it, so it transcribes one
@@ -63,3 +63,27 @@ compares it to what the provider will actually create. The one wrong instance wa
- What would have caught the wrong instance? A test that resolves a consumer's grant and compares the
bucket in its own configuration against the one the provider would create is a check that could
exist today, for any interface, without the mechanism above.
## Answered, 2026-10-02 — [ADR 0202](../../02-DECISIONS/0202-a-provider-declares-what-it-derives-for-each-consumer.md)
The channel is the provider's own `serves` block, which may now name the consumer the mesh is
serving: `${consumer:as}` and `${consumer:as:dns}`. The mesh fills it once, where it knows who the
consumer is, and delivers the one filled value to both ends — the consumer's binding and its
`${bound:…}` substitutions, and the provider's contributions entry, so a provisioner is told the
name rather than deriving it. Each open question above, answered:
- **Should a provider return values from provisioning?** No. It would make a grant carry data the
provider wrote, make a consumer's declaration wait on its provider's reconcile loop, and put the
rule where nothing can refuse it. The reasoning is in the record.
- **Or should `serves` say a value is derived?** Yes, and the mesh performs the derivation — but it
learns no protocol doing it. The only fact is the identity the mesh itself minted, in one of two
alphabets it already knows.
- **Should a consumer that names the resource be refused?** Yes. A consumer's file that already
contains the value the mesh is about to derive for it is refused at resolution, naming the
placeholder to write instead. That is the check this report asked for, and it is exact rather than
heuristic: a derived value carries the identity minted for this consumer on this machine, which
nothing else would spell out.
minio's `bucketFor` is gone; its manifest serves `"bucket": "${consumer:as:dns}"`. The three
consumers' hand-written bucket names are gone with it — each of them also named the machine the
module happens to run on, which is the second thing wrong with a transcription.
@@ -0,0 +1,93 @@
---
status: open
opened: 2026-10-02
located-in: [mesh-catalog modules/dnsmasq, mesh-controller cmd/mesh-controller]
fixed-by:
amended-design:
---
# 202 — A module whose required setting nobody set is left out of the machine, and the resolver is the module it happened to
## What was observed
Running the controller's own test suite against the catalogue beside it, 2026-10-02.
`TestTheResolverIsToldEveryMachineOnTheNetworkAndToldAgainWhenOneLeaves` fails with *"the resolver
was not handed the machines"*. Composing the same machine by hand and listing what it receives
shows why: **dnsmasq contributes nothing at all.** Four resources are composed for that node, all
of them the overlay's. The resolver's package, its configuration, its service and the fact that
carries every machine's name are simply not there.
The cause is one line added to `dnsmasq`'s configuration earlier the same day: the addresses it
listens on beside the machine's own became an operator setting,
`listen-address=${setting:listen-addresses}`, with no default. A `${setting:…}` nothing sets is
refused, a module that cannot be composed is **left out** rather than failing the whole machine
([ADR 0163](../../02-DECISIONS/0163-taking-a-module-over-is-a-comparison.md)), and so a node
assigned the resolver is handed a declaration with no resolver in it.
The failing test is the symptom that surfaced it. The test is not what is wrong.
**Proven rather than inferred.** Composing the same machine a second time with
`listen-addresses` set to `127.0.0.1` and nothing else changed, every one of dnsmasq's eight
resources appears — `needs-broker`, `mesh-state`, `package`, `config`, `runtime-dns`, `runtime`,
`service` and `fact-node-zones`. The only difference between a machine with a resolver and a
machine without one is whether somebody set a value that did not exist yesterday.
## Why it matters beyond this instance
**Leaving a module out is right, and being quiet about it is not.** The rule exists so one
module's broken setting cannot stop a machine converging — a good rule. But the outcome here is a
machine that applies cleanly, reports current, and is missing its DNS resolver. Every name on that
machine then resolves through whatever was there before, or not at all, and nothing in the mesh
says the resolver was dropped. That is the shape
[issue 152](../152-a-nodes-plan-failure-silently-drops-its-routed-names/00-report.md) records for
routed names, here for a whole module.
**And a setting with no default is a definition that cannot be assigned.** Every other
`${setting:…}` in the catalogue names something that is genuinely particular to one installation —
a public domain, an issuer. "Which addresses besides my own do I answer on" has an obvious correct
default for every machine that is not a LAN gateway: none beside loopback. A definition that
refuses to compose until somebody sets a value most machines do not need is a definition that
breaks the next node to be assigned it, and genesis with it.
## What this does not claim
Whether the live machines are affected was not checked — those four have had the setting set, or
their resolvers would already be gone. The claim is about a machine assigned the resolver *from
now on*, and about the silence.
## Open questions
- Should the declaration say which modules it left out, where a person or the console can see it?
`left_out` already travels to the host ([ADR 0163](../../02-DECISIONS/0163-taking-a-module-over-is-a-comparison.md));
what is missing is anything that reads it back and says so.
- ~~Should a `${setting:…}` be allowed a default?~~ **Decided in principle and not built.**
[ADR 0164](../../02-DECISIONS/0164-a-setting-is-declared-with-its-default-its-meaning-and-what-changing-it-costs.md)
(proposed, 2026-10-01) says a setting with a default is a tunable and one without is the
operator's, and narrows 0155's refusal to exactly the second. `listen-addresses` is a tunable by
that rule, and dnsmasq declares no settings block at all. So this issue is, in part, 0164 waiting
to be built — and in part the silence, which 0164 does not address.
- Is leaving a module out ever right for a module a node is **assigned**, as opposed to one it
merely pulls in? An assignment is somebody saying *this machine runs this*; silently not running
it is the one answer nobody asked for.
## Still true on 2026-10-04, and the evidence had to be re-taken
Re-checked after the bundles refactor landed (fourteen records, ADRs 0188 and 0190–0200). **The
fault stands and the old evidence no longer reaches it.**
`TestTheResolverIsToldEveryMachineOnTheNetworkAndToldAgainWhenOneLeaves` still fails on
mesh-controller main, with the same message — and now for a *different first reason*. `assign` is
refused before composition ever happens:
> dnsmasq on anchor has no bus credential: nothing was issued for anchor.dnsmasq … (novox/hq issue 203)
That is [issue 203](../203-a-fresh-assignment-is-pushed-before-its-credential-exists/00-report.md)'s
new guard doing its job on a test harness that mints no credential. Two faults are stacked in one
failing test, and the second was invisible behind the first.
Proven again, past both: mint `anchor.dnsmasq` so the assignment stands, then compose the machine
twice. **Without `listen-addresses` the node composes four resources, all the overlay's. With it
set to `127.0.0.1`, all eight of dnsmasq's appear** — `needs-broker`, `mesh-state`, `package`,
`config`, `runtime-dns`, `runtime`, `service`, `fact-node-zones`. Nothing else differs.
The test is now wrong about two things and should be fixed with whichever of these is fixed first.
@@ -1,9 +1,10 @@
---
status: located
status: resolved
opened: 2026-10-03
located-in:
- mesh-controller
fixed-by:
- mesh-controller#246
amended-design:
---
@@ -45,3 +46,7 @@ have to write — a bundle of language L depends on the module that publishes L'
bundle lands in the tier after it. A test: a merge touching the toolchain module and a TypeScript
bundle plans the bundle one tier later. Worked around on the day by building the bundle again once
the toolchain was built.
## Resolved
Every mesh-tools plan since the fix ran in two rounds: the toolchain and runtime images first, what is built in or on them after. Before it, a merge moving both tiered them together. The planner's test proves the order: a merge moving a bundle and its toolchain plans two rounds.
@@ -1,10 +1,11 @@
---
status: located
status: resolved
opened: 2026-10-03
located-in:
- mesh-tools
- mesh-controller
fixed-by:
- mesh-tools#44
amended-design:
---
@@ -42,3 +43,7 @@ install from a lockfile that a release updates, or build the install layer witho
the build should record which SDK version the image carries, so a bundle's record says what it was
compiled against. A check: after an SDK release and a toolchain rebuild, a bundle built on it reports
the released version.
## Resolved
The toolchain now installs the exact SDK version the mesh last published, passed in as a build argument from the SDK module's published package, and the planner orders the toolchain after the SDK. Proven 2026-10-04: the toolchain built with the published SDK, and the six TypeScript bundles built in it serve their tools and seat verbs.
@@ -1,10 +1,14 @@
---
status: open
status: resolved
opened: 2026-10-03
located-in:
- mesh-controller
- mesh-catalog
- mesh-host
fixed-by:
- mesh-host#86
- mesh-controller#252
- mesh-controller#253
- mesh-host#88
amended-design:
---
@@ -50,3 +54,27 @@ of a plan today.
Located only by owner; the move is a change of the controller's module and its deployment, not of
its code.
## Fix prepared (2026-10-04)
Three changes. mesh-host#86, merged: a process may name the container it `replaces`, and the host
removes that container only once the process has stayed up across two checks. mesh-controller#252,
awaiting the operator's merge: the controller's composition for a service process, and two
controllers safe together for the handover — the second stands by on the controller's consumers
until the first lets go, and all plan work holds one advisory lock. mesh-controller#253, held: the
controller's manifest as a Go bundle and a process. It waits on
[issue 223](../223-a-new-mesh-installs-its-controller-as-a-container/00-report.md), because with it a
new mesh cannot be installed.
## Resolved
Proven 2026-10-04 on the control machine: after the manifest change was merged and pushed, the host
created the controller's account, ran its preparation step, started the controller as a process,
found it up across both checks and removed the container. The controller now runs as its own account
from its bundle, no controller container remains, its seat answered throughout, and the merge's own
plan finished all three tiers under the new process.
One fault on the way, fixed before it could leave two controllers or none: the host read the account
not existing yet as a user database that did not answer — it matched the exit as text in a wording
its own runner did not use — so the first apply stopped at the account and the container kept serving,
which is the handover's safe failure (mesh-host#88).
@@ -1,9 +1,10 @@
---
status: located
status: resolved
opened: 2026-10-03
located-in:
- mesh-controller
fixed-by:
- mesh-controller#246
amended-design:
---
@@ -34,3 +35,7 @@ Owner mesh-controller (the planner). **Fix direction:** on start, and whenever a
build, the plan settles an `asked` build against the build records — a build recorded as built from
the plan's commit is that tier's outcome — so a plan resumes after the controller replaced itself.
A test: a plan whose build outcome was recorded while no controller followed it resumes on start.
## Resolved
A plan settles an asked build from the build records, whoever heard the outcome. Proven 2026-10-03 and 2026-10-04: both controller merge plans since the fix finished all three rounds, including the round that replaced the controller, without being stopped by hand.
@@ -1,9 +1,10 @@
---
status: located
status: resolved
opened: 2026-10-03
located-in:
- mesh-controller
fixed-by:
- mesh-controller#246
amended-design:
---
@@ -33,3 +34,9 @@ Owner mesh-controller. **Fix direction:** a build asked at a commit does not cha
module follows; or, if pinning is meant, the pin is said — in `module list`, in `status`, and by a
merge's plan naming the module it leaves out and why. A test: building a module at a commit and then
merging a change to it plans it.
## Resolved
Proven 2026-10-04: the catalogue merges since the fix rebuilt the module that had been pinned at an
old commit, at the merge's commit, by an ordinary plan — the same as every other module of the
catalogue. Nothing was asked for it by hand.
@@ -1,9 +1,10 @@
---
status: located
status: resolved
opened: 2026-10-03
located-in:
- mesh-controller
fixed-by:
- mesh-controller#246
amended-design:
---
@@ -28,3 +29,7 @@ Owner mesh-controller (the catalogue's registration check). **Fix direction:** a
loads, runs or unpacks — no `loads`, no `tools` list on its module, no resource naming it — is refused
at registration, naming the field that would deliver it. A test: such a manifest is refused; adding
`loads` admits it.
## Resolved
A bundle nothing would deliver is refused at registration, by name. Proven by the controller's tests; the catalogue's bundles all name what the runtime loads (mesh-catalog#243).
@@ -1,9 +1,11 @@
---
status: located
status: resolved
opened: 2026-10-03
located-in:
- mesh-tools
fixed-by:
- mesh-tools#42
- mesh-tools#43
amended-design:
---
@@ -50,3 +52,7 @@ announcement subscriptions are allowed for every principal kind.
Recovered on the day without the forge's API: the toolchain images built by the controller straight
from the fix branch, every module image rebuilt on them, and the machine pushed.
## Resolved
A refused announcement is logged and the runtime serves on, and every runtime subscribes only the discovery subjects its grants allow. Proven 2026-10-04: after rolling out to every machine, no container restarts anywhere, and the discovery console lists no runtime as not answering. A refused tool subscription was made non-fatal the same way afterwards, under issue 218 (mesh-tools#46).
@@ -1,9 +1,13 @@
---
status: located
status: resolved
opened: 2026-10-03
located-in:
- mesh-controller
fixed-by: mesh-controller#248
- mesh-tools
fixed-by:
- mesh-controller#248
- mesh-tools#45
- mesh-tools#46
amended-design:
---
@@ -63,3 +67,26 @@ and memberships come from the same list, so they cannot disagree.
seats and loses the recorded mesh seat. Live, the discovery console's overview must show each
mesh-scoped seat announced from exactly the holder the records name. Status moves to `resolved` once
that holds after the fix is rolled out.
## A second cause, and what the rollout broke (2026-10-04)
With the grants corrected, calls to the store reached only the holder, yet the console still showed
the seat announced from both machines. The module's runtime added every seat its start-up credential
claims, even after the mesh issued a membership that left the seat out. Once a membership exists,
it now alone decides which seat verbs a runtime serves (mesh-tools#45).
The rollout then exposed a third fault. The module on the machine that does not hold the seat was
still running an image built before #45, so it subscribed to the seat's subject. The corrected grants
refused that subscription, and the refusal ended the process. Its runtime crash-looped until the
module was rebuilt on the new runtime image. The database itself kept running. A refused tool
subscription is now logged and costs only that subject (mesh-tools#46), as a refused announcement
already did ([issue 217](../217-a-refused-announcement-took-down-every-containers-runtime/00-report.md)).
The module was not rebuilt by the plan that rebuilt the runtime image. This is the ordering gap of
[issue 211](../211-a-bundle-is-built-before-the-toolchain-it-is-compiled-in/00-report.md) seen
from a container module.
**Proven 2026-10-04.** The discovery console's overview shows the store seat announced from the
recorded holder only. Repeated calls to the store are answered by that machine, and the answers
include the controller's own database. The non-holder still answers its own module tools. No
container restarts on any machine.
@@ -0,0 +1,48 @@
---
status: resolved
opened: 2026-10-04
located-in:
- mesh-controller
fixed-by:
- mesh-controller#249
amended-design:
---
# 219 — An older build that finishes later replaces a newer one
## What was observed
2026-10-03. Two merges to the runtime module came minutes apart. Each plan asked for every module
built on the runtime image to be rebuilt. One module's two builds were of the same source and
differed only in the runtime image they stood on:
| Build | Requested | Finished | Stood on |
|---|---|---|---|
| asked by the first plan | 21:33 | 22:04 | the runtime image before the fix |
| asked by the second plan | 21:49 | 21:56 | the runtime image with the fix |
The older request finished last, and its image became the module's current artifact. The next push
deployed it, and the module's runtime crash-looped on a fault the newer image had already fixed
([issue 218](../218-a-mesh-seat-is-answered-by-a-module-that-does-not-hold-it/00-report.md)).
## Why it matters beyond this instance
Which build is current should follow what it was built from, not which build machine was slowest.
Whenever two plans overlap, which happens on any busy evening, a fix can be silently reverted by a
build that started before it existed. Every passing check still passes.
## Where to look
How a finished build is recorded and how a module's current artifact is chosen. **How it is checked:**
a test in which an older request completes after a newer one for the same artifact, and the newer
stays current.
## Resolved
A build is ordered by when it was requested, read from the id the controller gives it, and a
module's registered manifest is replaced only by a build requested at or after the one it came from.
An older request finishing later is recorded and changes nothing; a plan settles only from builds it
asked for itself. **How it is checked:** store-backed tests replay the incident — the newer request
stays what the module is — and fail without the fix. Live since 2026-10-04: the rebuilds of every
runtime-image module and the three waves of module code moves since then each registered the build
they asked for.
@@ -0,0 +1,41 @@
---
status: resolved
opened: 2026-10-04
located-in:
- mesh-host
fixed-by:
- mesh-host#84
amended-design:
---
# 220 — A delivered bundle keeps the files of the one before
## What was observed
2026-10-04. A tools bundle was rebuilt as one self-contained file per entrypoint
([ADR 0193](../../02-DECISIONS/0193-every-bundle-the-runtime-serves-is-launched-and-the-runtime-knows-no-language.md)),
so it no longer carries a package directory. On the machine it was delivered to, its directory still
held the package directory and a compiled file from the earlier delivery, dated hours before the
new files. The new files were written over the old directory, and nothing removed what the new
bundle no longer contains.
## Why it matters beyond this instance
A bundle on disk should be exactly the artifact that was built. Leftover files can be imported by
code that should no longer find them. A fix that removes a file then works on a fresh machine and
fails on every machine that ran an earlier version. It also makes "what runs here" impossible to
read from the artifact.
## Where to look
How the host unpacks a bundle into its directory. **How it is checked:** deliver a bundle, then a
version without one of its files, and the file is gone.
## Resolved
An archive is unpacked into a fresh directory beside the old one and swapped in by rename; a refused
or failed unpack leaves the old tree whole. **How it is checked:** a second delivery without a file
removes it, and nothing is left beside the directory; both tests fail without the fix. Proven
2026-10-04: a bundle rebuilt and delivered after the fix holds exactly the new build and nothing
beside it. A bundle that has not changed since keeps its old leftovers until its next version, by
design: an unchanged archive is not unpacked again.
@@ -0,0 +1,52 @@
---
status: resolved
opened: 2026-10-04
located-in:
- mesh-controller
fixed-by:
- policy: `upgrade build-agent roll-out` (2026-10-04)
amended-design:
---
# 221 — A build machine learns a new builder only from a push
## What was observed
2026-10-04. A controller merge changed how TypeScript bundles are built: one file per entrypoint
instead of a package directory. Its plan finished, and six bundles were rebuilt right after. They
came out in the old shape, because the build machines still ran the previous builder. They got the
new one only from the next push. Rebuilt after that push, the same six came out right.
The same order showed in the bus grants the same night. A push sent while the controller was still
the previous build composed grants with the previous code. A second push was needed after the new
controller had started.
## Why it matters beyond this instance
A merge to the controller is not in effect when its plan says done. Anything built or pushed in the
gap uses the old code and looks current. Today only the operator knows to push first and build
second, and even the operator forgot.
## Where to look
Whether a controller plan should end by delivering itself to the build machines and the control
machine, or whether a build should refuse a builder older than the controller that asked for it.
**How it is checked:** after a controller merge, a build asked right after its plan finishes runs
the new builder.
## Located
The mechanism existed: a module whose upgrade policy is `roll-out` is sent to its machines when its
tier is built, and the plan's next tier waits until it is applied. The build agent's policy was
`record` — built, never sent — as was that of 76 other modules, which is why every rollout on
2026-10-03 needed a push by hand. The build agent was set to `roll-out`, one machine at a time,
stopping at the first failure. **How it is checked:** the next controller merge's plan sends the
build agent to the build machines before its last tier, and a build asked right after the plan
finishes runs the new builder; then this moves to resolved. Whether the other modules roll out is
the operator's policy, not this issue's.
## Resolved
Proven 2026-10-04: the next controller merge's plan logged that its first tier was built and the
build agent sent to all four build machines, and only then asked its next tier. The builder change
in that merge reached the build machines without a hand push.
@@ -0,0 +1,51 @@
---
status: resolved
opened: 2026-10-04
located-in:
- mesh-tools
fixed-by:
- mesh-tools#47
amended-design:
---
# 222 — An assignment is refused on the bus until the bus's machine is pushed
## What was observed
2026-10-04. A module was assigned to the laptop, and the laptop alone was pushed. The module's two
bundles arrived and the node's runtime launched both, and then the bus refused every one of the
module's subjects:
```
nats: permissions violation: Permissions Violation for Subscription to "mesh.mod.<module>.tool.<tool>.<node>"
```
The tools were unreachable until a later push that included the machine running the bus. Then the
runtime served them without a restart, because a new membership arrived and it re-subscribed.
## Why it matters beyond this instance
What an account may answer lives in the bus's user list, and the controller writes that list only
into the declaration of the machine that runs the bus. Assigning anything to any machine changes
that list, so `push <machine>` after `assign <machine> <module>`, which is what the controller itself
tells the operator to run, leaves the module running and unreachable, with nothing reporting a fault.
## Where to look
Whether a push to one machine should also send the bus's machine when the user list it would
compose differs from the one that machine holds. **How it is checked:** assign a module with tools
to a machine that does not run the bus, push only that machine, and its tools answer.
## Diagnosed and resolved
The push did send the bus's machine: the controller's log shows both machines applying in the same
second. The fault was the order within that second. The node's runtime subscribed before the bus
had reloaded its user list, the bus refused, and the bus client marks a refused subscription dead.
Nothing asked again until a later membership happened to re-serve the module.
A subject the runtime answers on is now asked for again when the bus refuses it, after waits from
two seconds to two minutes, and given up and said after about five minutes. **How it is checked:**
a test refuses a subject and finds it asked for again and answering, given up past its attempts,
and not asked again once stopped; and by hand against a bus whose permissions were reloaded while
connected, the runtime answered two seconds after the grant arrived, where the runtime before the
fix never answered.
@@ -0,0 +1,60 @@
---
status: resolved
opened: 2026-10-04
located-in:
- mesh-host
fixed-by:
- mesh-host#87
amended-design:
---
# 223 — A new mesh installs its controller as a container
## What was observed
2026-10-04. Preparing [issue 213](../213-the-controller-is-a-go-program-run-in-a-container/00-report.md),
the controller's own manifest was changed to a Go bundle run as a process. The installer that raises a
new mesh assumes the controller is an image and a container at every step from its third on:
- it requires the controller's build to produce exactly one image;
- it starts a temporary controller from that image, and publishes the image to the registry;
- at the pivot, it finds the controller's container in the declaration, reads its environment and
volumes, waits for it, and from then on talks to the controller only through the container.
## Why it matters beyond this instance
With the controller's manifest changed, a new mesh cannot be installed: the pivot fails. The deeper
constraint is ordering. A process's bundle is fetched from the artifact store, and the installer
raises the artifact store only after the pivot, so the controller's first declaration names a bundle
nothing can serve yet.
## What a fix has to settle
One of two shapes, and it is a decision, not a repair:
1. raise the artifact store before the pivot, publish the controller's bundle to it, and talk to the
controller from the host's side rather than through a container; or
2. pivot to the image form as today, and let the first push hand over to the process, which
requires the controller's manifest to carry both forms.
Until it is settled, the change of the controller's manifest (mesh-controller#253) is held. The
handover itself is built and merged (mesh-host#86); the controller's half (mesh-controller#252) waits
on the operator. **How it is checked:** the installer's test raises a mesh whose controller manifest
is the process form, and the controller answers its seat's verbs at the end.
## Decided (2026-10-04)
Option 2, [ADR 0200](../../02-DECISIONS/0200-genesis-pivots-to-the-controller-as-a-container-and-the-first-push-hands-it-to-a-process.md):
genesis pivots to the controller as a container recorded under the name the process `replaces`, and
the first push hands it over.
## Resolved
Built as [ADR 0200](../../02-DECISIONS/0200-genesis-pivots-to-the-controller-as-a-container-and-the-first-push-hands-it-to-a-process.md)
decided: genesis reads only the controller's process from the manifest, builds the controller's image
from its repository, and pivots to a container of its own shape recorded under the id the process
`replaces`; an older controller in the image form still builds as before. **How it is checked:** the
installer's tests build the genesis form from the controller's real manifest, and apply the
controller's first process declaration over the recorded container with the host's own apply — the
process starts, the container is removed, one controller remains. A real install from nothing has not
been run since; the handover it ends in was proven live on the running mesh (issue 213).
@@ -0,0 +1,64 @@
---
status: open
opened: 2026-10-04
located-in: [mesh-host internal/apply/apply.go, mesh-host internal/apply/schedule.go]
fixed-by:
amended-design:
---
# 224 — An apply arriving during a maintenance window reopens it, by recreating the container the window is holding still
## What was observed
Reviewing [ADR 0189](../../02-DECISIONS/0189-the-store-keeps-what-the-records-name.md)'s
`while-stopped` before merging it, 2026-10-04. Found by reading, not by running.
A scheduled step may hold its module's containers still while it runs. The host stops them, runs
the step, starts them again. Nothing tells the **apply** that a window is open, and the apply's
rule for a container it finds stopped is to replace it:
```
case existed && (before.Spec == want || legacy) && before.Running && len(reasons) == 0:
out.Action = "unchanged"
case existed:
rm -f
```
`before.Running` is false for a container a window is holding, so the second branch takes it:
the container is removed and recreated, **running**, in the middle of the step that required it
to be still.
## Why it matters
For the store, which is what the field was built for, the chain is: a push lands at 03:30 → the
apply recreates the registry → the registry accepts an upload from a build running at the same
time → `garbage-collect`, already past its mark phase, sweeps the blob that upload just wrote.
The image is then in the store with a layer missing, and the build that made it reported success.
Two things have to coincide, so it is not likely. It is also not rare enough to leave unsaid: the
mesh pushes on every merge, at any hour, and a collection over a store this size is minutes rather
than seconds.
**The general shape is the one that matters.** `while-stopped` is the first thing in the mesh that
makes a container's stopped state *intentional*. Everything else in the host reads "stopped" as
"broken, fix it", which is right everywhere else and wrong here. Any future use of the field
inherits this.
## What this is not
Not a regression. The store has never collected anything, so nothing is worse than it was; this
is a hole in something new rather than something that broke.
## Open questions
- **Should a window take the apply lock?** The daemon already serialises applies with `applying`
and, across processes, with `store.Lock`. A window that held it would make the race impossible.
The cost is that a push arriving mid-window waits for minutes, and a push that waits is what
[issue 185](../185-a-refused-membership-publish-stops-the-controller/00-report.md)'s
family of outages looked like from outside.
- **Or should the apply learn that a container is held?** Narrower: the scheduler says which
containers a window currently holds, and `applyContainer` reports those unchanged instead of
recreating them. Nothing blocks, and the apply tells the truth for the minutes it matters —
at the cost of a second source for "is this container meant to be running".
- Either way: should the *report* say a window is open, so a machine that looks half-stopped at
03:31 reads as working rather than broken?
@@ -0,0 +1,75 @@
---
status: open
opened: 2026-10-04
located-in: [mesh-host internal/apply, mesh-controller internal/catalogue]
fixed-by:
amended-design:
---
# 225 — A provisioner cannot read the grant secrets since its code left the container, and every consumer of it is unserved
## What was observed
On the control machine, 2026-10-04, found while looking at why one app was restarting:
```
[mongodb] [provisioner:mongodb-database] mesh_novox_photos: secret not readable yet
(/var/lib/mongodb/grants/novox.photos.secret):
Error: EACCES: permission denied, open '/var/lib/mongodb/grants/novox.photos.secret'
```
**4330 times, every five seconds, since 01:30:20.** The consequence is not a log line: the
provisioner never reads the password, so it never creates the user, so the consumer never
connects —
```
UserNotFound: Could not find user "mesh_novox_photos" for db "admin"
```
— and the app crash-loops. Two consumers on this machine are in that state.
## Why
The grant secrets are what the mesh seals for each consumer and the host unseals beside the
provider's contributions file. They are written `-rw------- root root`, which was right while a
module's own code ran in a container as root.
[ADR 0198](../../02-DECISIONS/0198-a-modules-long-running-code-is-launched-by-the-node-runtime-and-reaches-the-bus-through-it.md)
moved a module's long-running code out of its container and under the node's runtime, which runs
as the operator's account. The provisioner is now that account; the secret is still root's. The
timestamps say it exactly: the files are dated 2026-09-26, the first refusal is 01:30:20 on the
day the runtime rolled.
**Nothing reports it.** The machine applies cleanly and reads as current; the provisioner says
`secret not readable yet`, whose wording is for a real and ordinary race on the first pass — the
host has not written the file yet — and which is indistinguishable, in the log, from a permanent
refusal. Four thousand occurrences of a message that means "wait a moment" is the shape to
recognise.
## Why it matters beyond this instance
This is every provider that provisions. The grant secret is the one file the sdk's harness reads
for every consumer, so a provider that cannot read it serves nobody — and says so only in a line
that reads like patience.
It is also the general question the runtime move leaves: **what the mesh seals for a module is
owned for the shape that module's code used to have.** Each module whose code moved is a module
whose files may now be unreadable to it, and ownership is the mesh's to state, not the module's
to work around.
## What this is not
Not caused by [ADR 0202](../../02-DECISIONS/0202-a-provider-declares-what-it-derives-for-each-consumer.md)
or [ADR 0189](../../02-DECISIONS/0189-the-store-keeps-what-the-records-name.md), which landed two
to three hours after the first refusal. Those rebuilt the two affected consumers, which recreated
their containers and made a silent fault visible as a restarting one. The dates are above.
## Open questions
- Who owns a grant secret now — the module's account, as `secrets-owner` already says for a
module's own secrets? Then the host writes it so, and this is a one-line statement in the
declaration rather than a convention.
- Should `secret not readable yet` stop saying "yet" after the first few passes? A message that
is right once and wrong four thousand times is a message that hides its own meaning.
- Which other modules' files did the runtime move leave behind? The sweep is the same question
for every path the mesh writes for a module: directories, bundles, received files.
@@ -0,0 +1,58 @@
---
status: open
opened: 2026-10-04
located-in: [mesh-controller cmd/mesh-controller/collect.go, mesh-controller internal/inventory/collection.go]
fixed-by:
amended-design:
---
# 226 — The store's sweep stops at the first reference recorded with an address, so it collects nothing at all
## What was observed
The first live run of [ADR 0189](../../02-DECISIONS/0189-the-store-keeps-what-the-records-name.md)'s
sweep, 2026-10-04, printed on every build:
```
the artifact store kept 127.0.0.1:5100/mesh-tools/build@sha256:0de48cd3…, so nothing more was
asked of it: 127.0.0.1:5100/mesh-tools/build@sha256:0de48cd3… is not a reference into the
mesh's artifact store
1681 more to collect; the next build asks again
```
Nothing is collected, and nothing ever will be. The store holds 1681 artifacts the mesh no longer
keeps and the feature that exists to remove them is inert.
## Why
Two correct decisions meeting badly.
**A reference recorded before references were kept without an address** is
`127.0.0.1:5100/<path>@sha256:…` rather than `artifact-store://<path>@sha256:…`
([04-ISSUES/102](../102-an-address-recorded-at-genesis-or-build-does-not-follow-the-nodes-ports/00-report.md)).
`LetGo` rightly refuses to compose a delete for a reference whose shape it does not recognise —
that refusal is what keeps the sweep from reaching something that is not the mesh's.
**The sweep stops at the first refusal**, because "a store that refuses one refuses all of them"
— deletion disabled, the store down, the network gone — and pushing through would mean a hundred
identical failures in front of whoever was building something. That reasoning is right for the
store refusing. It is wrong for *this* record being unreadable.
So one old record, early in the oldest-first order, halts the whole sweep for ever.
## Why it matters beyond this instance
**A guard that cannot tell "I will not ask about this" from "it would not answer" stops the wrong
amount of work.** The two deserve opposite responses: skip one, abandon the other. Collapsing
them into "an error" is how a bounded, cautious loop becomes a loop that does nothing — and it
reports the right number while doing it, which is what made it look healthy.
## What a fix has to settle
- A reference the sweep cannot address is **skipped, and the sweep goes on** — it is a fact about
that record, not about the store.
- `Recorded()` already normalises the old form to the kept one, and is what the rest of the mesh
uses for exactly these references. The sweep should normalise before asking rather than refuse.
- Only a refusal *by the store* ends a sweep.
- **How it is checked:** a sweep over records holding one address-recorded reference and one kept
one collects the second; a sweep against a store that refuses stops at the first.
@@ -0,0 +1,44 @@
---
status: open
opened: 2026-10-04
located-in: [mesh-catalog modules/photos]
fixed-by:
amended-design:
---
# 227 — The photo app's admin client asks for port 80, which the reverse proxy holds, so it cannot start
## What was observed
Applying the control machine, 2026-10-04:
```
applying "photos.admin-client": starting container photos-admin-client:
failed to bind host port 0.0.0.0:80/tcp: address already in use
```
Port 80 on that machine belongs to the reverse proxy (`mesh-route-proxy`, confirmed with `ss`),
which is the whole arrangement: the proxy holds the public ports and every module is reached
through it. A module that publishes 80 itself can never start beside it.
Everything else on the machine applied; this one resource fails every pass.
## How it surfaced
`photos` had been pinned at a commit from 2026-09-28 and was rebuilt to `main` on 2026-10-04 —
forced by [ADR 0202](../../02-DECISIONS/0202-a-provider-declares-what-it-derives-for-each-consumer.md)'s
refusal of its transcribed bucket name. The admin client is one of the changes that came with the
rest of `main`. The rebuild did not create the conflict; it delivered it.
**A module pinned months behind carries whatever its branch gained, all at once, the first time
something makes it move.** That is the cost of a pin, and it is paid in full rather than
gradually.
## What a fix has to settle
- Which port the admin client should ask for, or whether it should be reached through the proxy
like everything else and publish nothing.
- Whether a module declaring a port the machine's proxy already holds should be refused when it
is composed, rather than failing on the machine every pass. The mesh assigns ports
([ADR 0038](../../02-DECISIONS/0038-the-mesh-assigns-the-port.md)); a fixed 80 beside a proxy is
a statement it could check.
@@ -0,0 +1,52 @@
---
status: located
opened: 2026-10-04
located-in:
- mesh-host
fixed-by:
amended-design:
---
# 228 — A login the mesh set is never given back, and undeclaring one stops the node applying
## What was observed
2026-10-04. Before the shell module of to-be 38 WP5 was assigned anywhere, a review traced what the
host does with the `user` shape the module declares (the operator account, with the login shell zsh)
on three events: first assign, a later push, and unassign.
1. **Undeclaring a `user` stops the node applying anything, for good.**
- The host's removal has no case for a `user`, so the orphaned record fails with "no way to remove".
- Orphans are removed before the declaration's first resource, and that failure aborts the apply.
- The record stays in the host's store, so every later apply fails the same way.
This was reproduced in a throwaway test against the host's code: the apply produced no outcomes,
and an unrelated file in the same declaration was not written. Renaming the resource's id has the
same effect. A showcase module carries a `user` today and is exposed to it too.
2. **The shell the account had is never recorded.** [ADR 0176](../../02-DECISIONS/0176-the-login-shell-is-a-node-seat-and-execute-is-its-contract.md)
§2 says the host "gives back [the login shell] when the holding moves". The host keeps nothing to
give back.
3. **A login shell is set whether or not it exists.** A failed package install does not stop the
resources after it. `usermod --shell` on the distribution only warns about a missing or
non-executable shell, and succeeds. The host's read-back compares the user database's string,
which matches. So an account can be pointed at a shell that is not there, and console, ssh and
display-manager logins then fail. No machine hit this, because zsh was already installed on all
four.
## Why it matters beyond this instance
Unassigning any module with a login in it, the case the mesh promises is ordinary, wedges the
machine's applies until a person edits the host's store. It is the same class of failure as an
earlier archive that could not be removed: a shape the host can create and cannot take away.
## Located
mesh-host, `internal/apply`: `remove()` has no `user` case, and `applyUser` neither records the shell
it replaced nor checks the shell it sets. The fix is set out in
[to-be 41](../../03-DESIGN/01-to-be/41-the-shell-and-the-accounts-environment.md) WP1:
- a removal that never deletes an account;
- the login shell given back, if it is still the one the mesh set and the recorded one still exists;
- a shell refused before it is set unless it is executable and listed among the machine's shells
(a shell that refuses logins need only be executable, since the distribution does not list it and
the controller's own account uses one).
@@ -0,0 +1,61 @@
---
status: open
opened: 2026-10-04
located-in: []
fixed-by:
amended-design:
---
# 229 — A rollout cannot be followed through the mesh's tools, so an agent goes round them
## What was observed
2026-10-04, rolling out to-be 41. An agent drove the rollout through the mesh's MCP tools: the
controller seat's `status`, `plans`, `command`, and the forge's merge. Four times it left those tools
and posted JSON-RPC by hand to the node console's HTTP endpoint with `curl`:
1. **To wait for a plan.** `plans` answers once, with prose. Nothing waits for a plan to reach a tier,
finish or fail. An agent's tools cannot be called from a shell loop, so the only way to be told
when a plan moved was a background `curl` loop polling the console every twenty seconds and
matching the plan's line with `grep`.
2. **To read `status`.** `status` answers a paragraph of prose (the bus's user list), then a JSON
document, both inside one string. Picking out `behind`, `waiting` and `reported` took a script
that cut the string at the first brace and parsed the rest.
3. **To read one module out of `module list`,** whose output was too long to read whole for one line.
4. **To call a tool that arrived after the agent's session began.** The modules rolled out in that same
session added `node-login-shell.execute` and `zsh.zsh_config` to one machine. The agent's MCP
connection had been opened before the console moved to discovery ([ADR 0195](../../02-DECISIONS/0195-the-meshs-tools-are-found-by-address-not-announced-whole.md)).
It still held the flat catalogue the console announced then, which lacks both the new verbs and the five discovery tools (`mesh_call` among
them) the console announces now. Clearing a session does not reconnect its MCP servers, and the
console never sends a list-changed notice, so nothing told the client its list was stale. The agent
posted `mesh_machine` and `mesh_call` by hand. Reconnecting the server would have given it the
discovery tools, which reach any tool by address the moment it exists.
The calls were authorised, because the console is the operator's own surface. But each is a raw call
the mesh's tools were meant to make unnecessary ([ADR 0154](../../02-DECISIONS/0154-the-meshs-own-verbs-are-the-controller-seats-tools.md)
puts the controller's verbs behind the seat). Each is also a script that breaks silently when a
sentence in the prose changes.
## Why it matters beyond this instance
Every rollout an agent drives has the same shape: merge, wait for a plan, push, wait for reports,
check `status`. When the tools answer only once and only in prose, every agent writes its own poller
and its own parser. Those are invisible to review, different each time, and wrong the first time the
wording moves. An agent that cannot wait also tends to act early, which is the opposite of what a
rollout needs.
## What a fix has to settle
- A way to **wait** on the mesh's own progress. For example, `plans` and `status` could take a plan
or node and a bound, and answer when it moves or the bound passes. Or a verb could follow one plan
to its end.
- **Structured answers** from the controller's verbs, with the prose as a field beside the data, not
around it.
- Whether `command`'s generic answer should take a filter, or whether the verbs it is used for most
(`module list`, `node show`) deserve verbs of their own.
- **A client is told when the console's own surface changes.** The console announces `listChanged`
and sends the notice when what it lists changes, for example after an upgrade that changes its
tools. A long-running session then never keeps a list the console no longer serves. Discovery
already makes every module's tools reachable without the list changing.
How each is checked belongs to the record that settles it.
@@ -0,0 +1,87 @@
---
status: open
opened: 2026-10-04
located-in:
- mesh-host
- mesh-controller
fixed-by:
amended-design:
---
# 230 — A host that hands over to a newer one loses its report, and a plan waits for it for ever without saying so
## What was observed
2026-10-04, rolling out to-be 41. A new host build and a new controller were merged together. The
controller's plan built build-agent and sent every machine a fresh declaration, which also delivered
the new host. Three of the four machines logged, within the same second:
```
host 4bd7df099757 is delivered; standing aside so the launcher runs it
applied 546 resource(s)
applied, and could not tell the mesh: reporting: context canceled
nox-mesh-host-launch: running /usr/lib/nox-mesh-host/versions/4bd7df099757/nox-mesh-host
```
The new host came up and waited for its next declaration. The mesh never heard that the old one had
applied.
The plan then sat at "tier 1 built; waiting for build-agent on [three machines] to be applied", and
everything the mesh said about it read as healthy:
- `status` showed it as `rolling` with `"late": false`;
- `plans` printed "for 0s" on every look, so the wait never appeared to grow;
- the three machines' reports showed `current: false`, which reads like a machine that is merely slow.
Nothing logged, alerted or counted the wait. It was found because a person asked twice for the plan's
state, and the cause was found by reading a machine's own journal. A push to each of the three machines
released it: each new host applied and reported, and the plan moved on.
The same day, a second way to lose a report showed up. Assigning modules with tools to a workstation
changed the bus's user list, which the control machine's declaration carries. Applying it replaced the
bus's container, which cut every machine off for about fifteen seconds. The control machine itself
then logged `applied, and could not tell the mesh: reporting: nats: connection closed`. The report was
lost because the bus restarted under the apply that restarted it.
## Why it matters beyond this instance
**Every genuine host upgrade loses one report.**
[Issue 163](../163-a-delivered-host-stood-aside-on-every-push-and-reported-nothing/00-report.md) fixed
the host that stood aside on every push for the version it already ran. It named the mechanism, that
standing aside cancels the context the report is published with. That fix made standing aside
happen only for a real new version, but left the mechanism in place. So whenever a host build reaches
a machine, that apply's report is lost.
**And the mesh cannot tell a stuck wait from a slow one.** A plan that waits on a report that will
never come waits for ever, and nothing about it changes:
- its age does not grow ("for 0s");
- `late` stays false;
- nothing logs, emits an event or alerts.
This is [issue 187](../187-the-mesh-tells-nobody-when-it-stops-working/00-report.md)'s class of fault
again, *the mesh tells nobody when it stops working*, now in the rollout machinery that every merge
goes through. The operator's rule from issue 163 applies: if an answer has not come in the time an
answer takes, something is wrong, and the mesh must say so itself.
## What a fix has to settle
1. **A report survives whatever its own apply restarts.** The host publishes its report and has it
acknowledged before it stands aside. It retries a report the bus dropped once the link is back.
Failing that, the new host should report the declaration it took over,
naming the apply its predecessor finished. A lost report must be impossible, not merely unlikely.
2. **A plan's wait has an age and a bound.**
- "for 0s" must be the real time since the wait began.
- A wait past a bound, set by how long an apply takes rather than by a guess, makes the plan
`late`.
3. **Late is said where people and agents look.**
- It is said in `status` and in `plans`.
- It is logged as a warning by the controller.
- It is emitted as an event under the controller seat, so something can alert on it.
4. **A plan waiting on a machine the mesh has stopped hearing from** says that, by name, instead of
waiting. The machine's heartbeat already tells the controller it is alive. A live machine with an
unacknowledged declaration is the stuck case itself.
How each is checked belongs to the fix. For the host: a delivered upgrade, applied, is reported. For
the controller: a plan whose machine never reports turns `late` within its bound, and says so in
`status`, the log and an event.