From 7bd04342b6cc60c062f3674a462b275bc4fc4fb5 Mon Sep 17 00:00:00 2001
From: jochen <jschoubben@gmail.com>
Date: Sun, 11 Oct 2026 11:23:12 +0200
Subject: [PATCH 1/4] Pin the node-engine at its pull request's generation
 refusal, so the validator reads a declaration's generation (hq issue 234)

---
 go.mod                                        |  4 +--
 go.sum                                        |  8 ++---
 .../novox/mesh-sdk/go/asks/asks.go            | 17 ++++++++++-
 .../internal/declaration/declaration.go       | 30 ++++++++++++++++++-
 vendor/modules.txt                            |  6 ++--
 5 files changed, 54 insertions(+), 11 deletions(-)

diff --git a/go.mod b/go.mod
index 067a2f55..cdf300d5 100644
--- a/go.mod
+++ b/go.mod
@@ -3,7 +3,7 @@ module github.com/novox/mesh-controller
 go 1.26.0
 
 require (
-	git.novox.be/novox/mesh-sdk/go v0.1.11-0.20261009143344-f047d0a4a970
+	git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261010191001-33917f91ac3c
 	github.com/jackc/pgx/v5 v5.10.0
 	github.com/nats-io/nats-server/v2 v2.11.17
 	github.com/nats-io/nats.go v1.54.0
@@ -35,4 +35,4 @@ require (
 // committed. Every build (the build agent's `go build`, the Dockerfile) compiles from vendor/ and
 // fetches nothing; go refuses to build when vendor/ and this file disagree, so a pin moved without
 // `go mod vendor` fails loudly, at once, everywhere.
-replace github.com/novox/mesh-host => git.novox.be/novox/mesh-host v0.0.0-20261009231844-b8c854611812
+replace github.com/novox/mesh-host => git.novox.be/novox/mesh-host v0.0.0-20261011092230-20d5af9b2d5f
diff --git a/go.sum b/go.sum
index c7f30d1a..e7436cbb 100644
--- a/go.sum
+++ b/go.sum
@@ -1,7 +1,7 @@
-git.novox.be/novox/mesh-host v0.0.0-20261009231844-b8c854611812 h1:pzVzwF5VMWaTECxu8+Pd1dNoOHNEm7upC5wPadQTkBw=
-git.novox.be/novox/mesh-host v0.0.0-20261009231844-b8c854611812/go.mod h1:K3/xEzVgmrNKLMV2vv4M80MwmPnQNXqvQ4C5Jj0fJT4=
-git.novox.be/novox/mesh-sdk/go v0.1.11-0.20261009143344-f047d0a4a970 h1:9tFDQsgmI+4X7/BpZGXIr+HemPKE7YddYGqWV0lINAI=
-git.novox.be/novox/mesh-sdk/go v0.1.11-0.20261009143344-f047d0a4a970/go.mod h1:GFuZUElBZ9A++mxgIKo97aXXo+kV0uJ/UkbhQPPIbrY=
+git.novox.be/novox/mesh-host v0.0.0-20261011092230-20d5af9b2d5f h1:8N5OW2mdTNIck2pe4EciTYX5NsrPsHrTLENGNIWYNTU=
+git.novox.be/novox/mesh-host v0.0.0-20261011092230-20d5af9b2d5f/go.mod h1:tcTK4LMs1d6JpZUwy3hSHMFG/MIuDr/XFs7/nbeaW/c=
+git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261010191001-33917f91ac3c h1:l5onJwoIeH8yE/PjVlEeoPyXBsHp2NQiWLllz2fwX7s=
+git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261010191001-33917f91ac3c/go.mod h1:GFuZUElBZ9A++mxgIKo97aXXo+kV0uJ/UkbhQPPIbrY=
 github.com/antithesishq/antithesis-sdk-go v0.7.0-default-no-op h1:Z/MZK75wC/NSrkgqeNIa7jexam9uWzhLmFTSCPI/kn0=
 github.com/antithesishq/antithesis-sdk-go v0.7.0-default-no-op/go.mod h1:FQyySiasQQM8735Ddel3MRojmy4dA1IqCeyJ5jmPMbI=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
diff --git a/vendor/git.novox.be/novox/mesh-sdk/go/asks/asks.go b/vendor/git.novox.be/novox/mesh-sdk/go/asks/asks.go
index 81737ac4..008e69af 100644
--- a/vendor/git.novox.be/novox/mesh-sdk/go/asks/asks.go
+++ b/vendor/git.novox.be/novox/mesh-sdk/go/asks/asks.go
@@ -154,7 +154,9 @@ func canonical(b *strings.Builder, v string) {
 //
 // It is over the ask's named fields in a fixed order, each written canonically, and the expiry as UTC
 // RFC 3339 to the nanosecond — never over a language's encoding of the struct, so a field added to Ask
-// later changes no digest until it is added here, on purpose.
+// later changes no digest until it is added here, on purpose. Whole and Details (novox/hq issue 383) follow
+// the options only when the ask gives either: an ask without them digests as it did before they existed, so
+// a router and an asker of different builds still agree on every such ask.
 func (a Ask) Digest() string {
 	var b strings.Builder
 	b.WriteString("novox.ask.v1\n")
@@ -168,6 +170,10 @@ func (a Ask) Digest() string {
 			canonical(&b, v)
 		}
 	}
+	if a.Whole != "" || a.Details != "" {
+		canonical(&b, a.Whole)
+		canonical(&b, a.Details)
+	}
 	sum := sha256.Sum256([]byte(b.String()))
 	return "sha256:" + hex.EncodeToString(sum[:])
 }
@@ -190,6 +196,15 @@ type Ask struct {
 	// About is what the ask is about (a condition's key): a newer ask about it replaces the older.
 	About  string `json:"about,omitempty"`
 	Urgent bool   `json:"urgent,omitempty"`
+	// Whole is the explanation with its exact values whole, shown in place of Explanation on a channel kind
+	// that proves who answers (verified-sender) and carries the ask's answers (novox/hq issue 383): what the
+	// person approves — a mount point, a share, a private address — must be readable where they approve it.
+	// The asker withholds a value shaped like a secret in it, and the router refuses the ask when one is left;
+	// Explanation stays under the whole content rule everywhere else. Empty, Explanation is shown everywhere.
+	Whole string `json:"whole,omitempty"`
+	// Details is what the Details answer on the ask's message shows, line by line under the content rule: a
+	// fingerprint, how to read the proposal whole at the terminal. Empty, an ask's own message offers no Details.
+	Details string `json:"details,omitempty"`
 }
 
 // The bounds of an ask (novox/hq ADR 0234 §8, ADR 0259 §4).
diff --git a/vendor/github.com/novox/mesh-host/internal/declaration/declaration.go b/vendor/github.com/novox/mesh-host/internal/declaration/declaration.go
index ea03cf57..50db892e 100644
--- a/vendor/github.com/novox/mesh-host/internal/declaration/declaration.go
+++ b/vendor/github.com/novox/mesh-host/internal/declaration/declaration.go
@@ -1378,6 +1378,20 @@ type Declaration struct {
 	// what it wrote for it — its resources are absent from the declaration, and absence would
 	// otherwise read as removal.
 	LeftOut []string
+
+	// Generation is the assignment generation this declaration was composed from: the controller's
+	// counter, raised in the same transaction as every change to what is assigned where (novox/hq
+	// issue 234). The sequence orders arrival and cannot tell a later send that carries an older view
+	// of the assignments; this can. A node-engine refuses a declaration composed from a generation
+	// older than the highest it applied — unless it is a put-back — because applying it would
+	// undeclare what the mesh still assigns. Zero is a declaration from a controller that claims none,
+	// and is applied as before.
+	Generation int64
+
+	// PutBack says this declaration is a gate putting a machine back (novox/hq issue 234): it carries
+	// the generation of what it puts back, which may be older than what the machine applied, and is
+	// not refused for it.
+	PutBack bool
 }
 
 // LeftOutModuleOf says which left-out module a recorded resource belongs to, if any: its id is the
@@ -1542,6 +1556,11 @@ type envelope struct {
 	Epoch int64 `json:"epoch,omitempty"`
 	// LeftOut is optional on the wire too, and absent when nothing was left out (ADR 0163).
 	LeftOut []string `json:"left_out,omitempty"`
+	// Generation and PutBack are optional on the wire too (novox/hq issue 234): absent is a controller
+	// that claims no generation. **An older host refuses these keys**, decoding strictly; a controller
+	// sends them only to a host whose reports say `reads_generation`.
+	Generation int64 `json:"generation,omitempty"`
+	PutBack    bool  `json:"put_back,omitempty"`
 }
 
 func parse(raw []byte, allowActions bool) (*Declaration, error) {
@@ -1559,8 +1578,17 @@ func parse(raw []byte, allowActions bool) (*Declaration, error) {
 	}
 
 	d := &Declaration{Version: env.Version, For: env.For, Adoption: env.Adoption, Sequence: env.Sequence,
-		Epoch: env.Epoch, LeftOut: env.LeftOut}
+		Epoch: env.Epoch, LeftOut: env.LeftOut, Generation: env.Generation, PutBack: env.PutBack}
 	var problems []string
+	if env.Generation < 0 {
+		// Below zero would read as "none claimed" and pass every refusal of an older generation.
+		problems = append(problems, fmt.Sprintf("an assignment generation below zero (%d) is not one the "+
+			"mesh assigns", env.Generation))
+	}
+	if env.PutBack && allowActions {
+		// A put-back is a gate's, sent by the mesh; a carried bundle puts nothing back.
+		problems = append(problems, "a carried bundle says it is a put-back, and only the mesh's gate can say that")
+	}
 	if env.Sequence < 0 || env.Epoch < 0 {
 		// Below zero is no order any controller assigns, and read as "none claimed" it would let the
 		// declaration past every refusal of what is older.
diff --git a/vendor/modules.txt b/vendor/modules.txt
index 486530b9..bb6a448e 100644
--- a/vendor/modules.txt
+++ b/vendor/modules.txt
@@ -1,4 +1,4 @@
-# git.novox.be/novox/mesh-sdk/go v0.1.11-0.20261009143344-f047d0a4a970
+# git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261010191001-33917f91ac3c
 ## explicit; go 1.22
 git.novox.be/novox/mesh-sdk/go/asks
 # github.com/antithesishq/antithesis-sdk-go v0.7.0-default-no-op
@@ -78,7 +78,7 @@ github.com/nats-io/nkeys
 # github.com/nats-io/nuid v1.0.1
 ## explicit
 github.com/nats-io/nuid
-# github.com/novox/mesh-host v0.0.0 => git.novox.be/novox/mesh-host v0.0.0-20261009231844-b8c854611812
+# github.com/novox/mesh-host v0.0.0 => git.novox.be/novox/mesh-host v0.0.0-20261011092230-20d5af9b2d5f
 ## explicit; go 1.26.0
 github.com/novox/mesh-host/internal/declaration
 github.com/novox/mesh-host/rootsearch
@@ -135,4 +135,4 @@ golang.org/x/text/width
 # golang.org/x/time v0.15.0
 ## explicit; go 1.25.0
 golang.org/x/time/rate
-# github.com/novox/mesh-host => git.novox.be/novox/mesh-host v0.0.0-20261009231844-b8c854611812
+# github.com/novox/mesh-host => git.novox.be/novox/mesh-host v0.0.0-20261011092230-20d5af9b2d5f

From 72fde0ee1ab933d192727ccbad73444797e6de33 Mon Sep 17 00:00:00 2001
From: jochen <jschoubben@gmail.com>
Date: Sun, 11 Oct 2026 11:30:16 +0200
Subject: [PATCH 2/4] Capture the SDK's conformance fixtures at the commit the
 node-engine's pin moved it to (hq issue 449's rule)

---
 testdata/beside/CAPTURED | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/testdata/beside/CAPTURED b/testdata/beside/CAPTURED
index 17d63986..f922ff40 100644
--- a/testdata/beside/CAPTURED
+++ b/testdata/beside/CAPTURED
@@ -9,7 +9,7 @@ a second place to clean besides the catalogue itself.
 
 mesh-catalog  b9de001833b1b61b297182b8e3bcdae1cbdeace9  modules/*/module.json, modules/nats/Dockerfile
 mesh-host     bd5cc6980419c1bd4824be6d58dfebd2381a9de3  examples/foundation-first-node-nats.lock
-mesh-sdk      f047d0a4a9702f5d7f3d7eadd3e62496311acc00  conformance/events/module-event.json
+mesh-sdk      33917f91ac3cc213b879b32f3c70e2aa70395f98  conformance/events/module-event.json
 
 To move them, from this repository's root, with the two repositories checked out beside it:
 

From 313efa826cec458a1d1c848eadc8e7e84b802707 Mon Sep 17 00:00:00 2001
From: jochen <jschoubben@gmail.com>
Date: Sun, 11 Oct 2026 11:30:16 +0200
Subject: [PATCH 3/4] Say in every declaration the assignment generation it
 came from, and record every send (hq issue 234)

A declaration newer in sequence than every other named four fewer modules
than the assignments held, a machine applied it, and nothing the mesh kept
said who sent it or from what view. The store now raises an assignment
generation in the same transaction as every assignment change (a trigger,
so a cascade counts too); a send reads it before composing, carries it to
engines that said they read it, marks a gate's put-back, and is recorded
with its sequence, sender, generation and modules. The would-send is
stamped with what was last sent, so nothing reads behind for it; a refusal
is kept on the send it refused and raised as S20 naming the sender; plan
says what the machine was last told.
---
 cmd/mesh-controller/facts.go                  |   4 +
 cmd/mesh-controller/gate.go                   |   5 +-
 cmd/mesh-controller/generation.go             | 195 +++++++++++++++++
 cmd/mesh-controller/generation_test.go        | 107 ++++++++++
 cmd/mesh-controller/held_back_test.go         |   2 +-
 cmd/mesh-controller/issue_204_test.go         |   2 +-
 cmd/mesh-controller/plan.go                   |   8 +-
 cmd/mesh-controller/push.go                   |  58 ++++-
 cmd/mesh-controller/release.go                |   3 +
 cmd/mesh-controller/sendable.go               |  25 +++
 cmd/mesh-controller/signals.go                |  14 ++
 cmd/mesh-controller/signals_test.go           |   8 +
 cmd/mesh-controller/status_summary.go         |   5 +
 cmd/mesh-controller/watchdogs.go              |   5 +
 ...ation-says-the-generation-it-came-from.sql |  64 ++++++
 internal/inventory/sends.go                   | 202 ++++++++++++++++++
 internal/inventory/sends_test.go              | 138 ++++++++++++
 internal/link/enrolment.go                    |   7 +
 internal/link/generation_test.go              |  33 +++
 internal/link/protocol.go                     |  16 ++
 20 files changed, 889 insertions(+), 12 deletions(-)
 create mode 100644 cmd/mesh-controller/generation.go
 create mode 100644 cmd/mesh-controller/generation_test.go
 create mode 100644 internal/inventory/migrations/0094-a-declaration-says-the-generation-it-came-from.sql
 create mode 100644 internal/inventory/sends.go
 create mode 100644 internal/inventory/sends_test.go
 create mode 100644 internal/link/generation_test.go

diff --git a/cmd/mesh-controller/facts.go b/cmd/mesh-controller/facts.go
index d24cc913..c1b6c891 100644
--- a/cmd/mesh-controller/facts.go
+++ b/cmd/mesh-controller/facts.go
@@ -514,6 +514,10 @@ func composedAndValidated(ctx context.Context, open *stores, node string, gens m
 	if declared.Epoch, err = open.inventory.SentEpoch(ctx, record.ID); err != nil {
 		return sendable{}, nil, err
 	}
+	// And the generation it was last sent, as the would-send is (novox/hq issue 234).
+	if declared.Generation, declared.PutBack, err = open.inventory.SentGeneration(ctx, record.ID); err != nil {
+		return sendable{}, nil, err
+	}
 	body, err := declared.Body()
 	if err != nil {
 		return sendable{}, nil, err
diff --git a/cmd/mesh-controller/gate.go b/cmd/mesh-controller/gate.go
index 36eefc4d..d7a71972 100644
--- a/cmd/mesh-controller/gate.go
+++ b/cmd/mesh-controller/gate.go
@@ -994,7 +994,8 @@ func gateFailed(ctx context.Context, open *stores, p *inventory.Plan, module str
 		}
 		return
 	}
-	sent, err := sendRollout(withScope(ctx, sendScope{modules: map[string]bool{module: true}}), open, g.Machines)
+	sent, err := sendRollout(withScope(ctx, sendScope{modules: map[string]bool{module: true}, putBack: true}), open,
+		g.Machines)
 	if err != nil {
 		notBack(fmt.Sprintf("its registered build is back at %s, and sending it to %s was refused: %v — `push %s` "+
 			"sends it", short(previous.Commit), strings.Join(g.Machines, ", "), err, g.Machines[0]))
@@ -1087,7 +1088,7 @@ func sendRollbacks(ctx context.Context, open *stores, p *inventory.Plan, b *roll
 	}
 	inv := open.inventory
 	sort.Strings(b.machines)
-	sent, err := sendRollout(withScope(ctx, sendScope{modules: b.modules}), open, b.machines)
+	sent, err := sendRollout(withScope(ctx, sendScope{modules: b.modules, putBack: true}), open, b.machines)
 	var back []string
 	for _, r := range b.pending {
 		if err != nil {
diff --git a/cmd/mesh-controller/generation.go b/cmd/mesh-controller/generation.go
new file mode 100644
index 00000000..f42d3fff
--- /dev/null
+++ b/cmd/mesh-controller/generation.go
@@ -0,0 +1,195 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"os"
+	"sort"
+	"strings"
+	"time"
+
+	"github.com/novox/mesh-controller/internal/catalogue"
+	"github.com/novox/mesh-controller/internal/conditions"
+	"github.com/novox/mesh-controller/internal/inventory"
+	"github.com/novox/mesh-controller/internal/link"
+)
+
+// The assignment generation a declaration was composed from, and the record of every send (novox/hq
+// issue 234).
+//
+// On 2026-10-04 a declaration newer in sequence than every other named four fewer modules than the
+// assignments held, and a machine applied it and undeclared all four. The sequence orders arrival and
+// cannot tell a later send that carries an older view of the assignments. So a declaration now carries
+// the generation of the assignments it was composed from — a counter the store raises in the same
+// transaction as every assignment change — and a machine refuses one older than it applied, unless it is
+// a gate's put-back. And every send is written down with who sent it, from which generation and naming
+// which modules: the controller logged no send then, and which process sent the stale declaration could
+// not be read back from anything the mesh kept.
+
+// kindOlderGeneration is S20's kind: a machine refused a send for the generation it was composed from.
+const kindOlderGeneration = "older-generation"
+
+// generationRefusalsSaid is how long a refused send is said after its refusal: an hour, as an advisory is.
+const generationRefusalsSaid = advisoryQuiet
+
+// stamp gives a composed declaration the order allotted to it before it was composed: its sequence, the
+// epoch and generation when the machine reads them, and the put-back mark beside a generation — and keeps
+// the generation and acting epoch for the record of the send whether or not the machine is sent them.
+func (o order) stamp(d *sendable) {
+	d.Sequence, d.Epoch = o.sequence, o.epoch
+	d.composedFrom, d.actingEpoch, d.putBackSend = o.generation, o.acting, o.putBack
+	d.Generation, d.PutBack = 0, false
+	if o.readsGeneration && o.generation > 0 {
+		d.Generation, d.PutBack = o.generation, o.putBack
+	}
+}
+
+// sentRecord is what the record of a send keeps beside its digest.
+type sentRecord struct {
+	sequence   int64
+	epoch      uint64
+	generation int64
+	putBack    bool
+	// told is the generation and put-back mark on the wire, which the would-send is stamped with.
+	toldGeneration int64
+	toldPutBack    bool
+	sender         string
+	modules        []string
+}
+
+// sentRecordOf is a composed send's record: its sender is the caller this process acts for.
+func sentRecordOf(ctx context.Context, d sendable) sentRecord {
+	return sentRecord{sequence: d.Sequence, epoch: d.actingEpoch, generation: d.composedFrom, putBack: d.putBackSend,
+		toldGeneration: d.Generation, toldPutBack: d.PutBack, sender: senderOf(callerOf(ctx)), modules: d.modules}
+}
+
+// callerOf is who asked for what this process does: the seat call's caller when ctx belongs to one, the
+// caller the controller ran this command for, or the account at the shell.
+func callerOf(ctx context.Context) string {
+	if c := link.CallerIn(ctx); c != "" {
+		return c
+	}
+	return link.Caller()
+}
+
+// senderOf is a send's sender in words: who asked, and the process and build that composed it — the
+// answer issue 234 could not find, because two controllers and a one-shot push were all sending then.
+func senderOf(caller string) string {
+	host, _ := os.Hostname()
+	return fmt.Sprintf("%s (pid %d on %s, build %s)", caller, os.Getpid(), host, version)
+}
+
+// namedModules are the modules a declaration names: its machine's set, less what was left out of it.
+func namedModules(plan catalogue.Resolution, leftOut map[string]string) []string {
+	out := make([]string, 0, len(plan.Modules))
+	for _, m := range plan.Modules {
+		if _, left := leftOut[m.Module]; !left {
+			out = append(out, m.Module)
+		}
+	}
+	sort.Strings(out)
+	return out
+}
+
+// heardGenerationRefusal keeps a machine's refusal of a send for its generation on the send it refused,
+// so S20 names its sender, and says it (novox/hq issue 234).
+//
+// **And raises the mesh's counter past what the machine applied, when the refused send was composed from
+// the counter as it stands**: then the sender's view was not stale — the counter is behind the machine,
+// which is a store put back from a backup — and every send after would be refused for ever. A stale
+// sender's generation is below the counter, and the counter is left alone for it.
+func heardGenerationRefusal(ctx context.Context, inv *inventory.Inventory, report link.Report) {
+	r := report.OlderGeneration
+	if r == nil || inv == nil || report.Node == "" {
+		return
+	}
+	node, err := inv.NodeByName(ctx, report.Node)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "mesh-controller: %s refused a send for its generation, and the machine cannot be read: %v\n",
+			report.Node, err)
+		return
+	}
+	send, found, err := inv.RefusedSend(ctx, node.ID, report.Sequence, r.Applied)
+	switch {
+	case err != nil:
+		fmt.Fprintf(os.Stderr, "mesh-controller: %s refused send %d for its generation, and the refusal could not be "+
+			"kept: %v\n", report.Node, report.Sequence, err)
+	case !found:
+		fmt.Fprintf(os.Stderr, "mesh-controller: %s refused send %d (generation %d; it applied %d), which the mesh "+
+			"has no record of sending\n", report.Node, report.Sequence, r.Generation, r.Applied)
+	default:
+		fmt.Fprintf(os.Stderr, "mesh-controller: %s refused send %d from %s: composed from assignment generation %d, "+
+			"and it applied %d\n", report.Node, report.Sequence, send.Sender, r.Generation, r.Applied)
+	}
+	now, err := inv.AssignmentGeneration(ctx)
+	if err != nil || r.Generation < now || r.Applied < now {
+		return
+	}
+	raised, err := inv.RaiseAssignmentGeneration(ctx, r.Applied)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "mesh-controller: the assignment generation (%d) is behind what %s applied (%d), and "+
+			"could not be raised: %v\n", now, report.Node, r.Applied, err)
+		return
+	}
+	fmt.Fprintf(os.Stderr, "mesh-controller: the assignment generation was %d, behind what %s applied (%d) — a store "+
+		"put back from a backup — and is raised to %d, so the next send is not refused\n", now, report.Node, r.Applied,
+		raised)
+}
+
+// watchGenerationRefusals is S20: every send a machine refused within the hour for the generation it was
+// composed from, naming who sent it (novox/hq issue 234). One per machine, the newest refusal.
+func watchGenerationRefusals(f *signalFacts) []conditions.Observation {
+	seen := map[string]bool{}
+	var out []conditions.Observation
+	for _, s := range f.refusedSends {
+		if s.RefusedAt == nil || f.now.Sub(*s.RefusedAt) > generationRefusalsSaid || seen[s.NodeName] {
+			continue
+		}
+		seen[s.NodeName] = true
+		out = append(out, conditions.Observation{Scope: conditions.ScopeMachine, ID: s.NodeName, Kind: kindOlderGeneration,
+			Machine: s.NodeName, Severity: conditions.Warning,
+			Summary: fmt.Sprintf("%s refused sequence %d from %s: it was composed from assignment generation %d, and "+
+				"%s applied generation %d — a sender composing from a view of the assignments the mesh has moved "+
+				"past; it named %s", s.NodeName, s.Sequence, s.Sender, s.Generation, s.NodeName, s.RefusedApplied,
+				modulesWords(s.Modules)),
+			Said:     fmt.Sprintf("refused at %s", s.RefusedAt.UTC().Format(time.RFC3339)),
+			Headline: fmt.Sprintf("%s refused an out-of-date update", s.NodeName),
+			Explanation: fmt.Sprintf("Something sent %s an update made from an older list of what runs there. %s "+
+				"refused it, so nothing was removed. Nothing for you to do unless it repeats.", s.NodeName, s.NodeName),
+			Resolved: fmt.Sprintf("%s has had no out-of-date update for an hour", s.NodeName)})
+	}
+	return out
+}
+
+// modulesWords is a send's modules as a sentence says them.
+func modulesWords(modules []string) string {
+	if len(modules) == 0 {
+		return "no module the mesh recorded"
+	}
+	return strings.Join(modules, ", ")
+}
+
+// writeLastSend says what a machine was last told, by whom and from which generation (novox/hq issue 234):
+// nothing when the mesh has not recorded a send to it.
+func writeLastSend(ctx context.Context, w io.Writer, inv *inventory.Inventory, node string) error {
+	s, found, err := inv.LastSend(ctx, node)
+	if err != nil || !found {
+		return err
+	}
+	generation := "no generation recorded"
+	if s.Generation > 0 {
+		generation = fmt.Sprintf("assignment generation %d", s.Generation)
+	}
+	kind := "sent"
+	if s.PutBack {
+		kind = "put back"
+	}
+	fmt.Fprintf(w, "%s was last %s sequence %d at %s by %s, composed from %s, naming %s\n", node, kind,
+		s.Sequence, s.SentAt.Local().Format("2006-01-02 15:04:05"), s.Sender, generation, modulesWords(s.Modules))
+	if s.RefusedAt != nil {
+		fmt.Fprintf(w, "  and refused it at %s: it had applied generation %d\n",
+			s.RefusedAt.Local().Format("2006-01-02 15:04:05"), s.RefusedApplied)
+	}
+	return nil
+}
diff --git a/cmd/mesh-controller/generation_test.go b/cmd/mesh-controller/generation_test.go
new file mode 100644
index 00000000..f794760c
--- /dev/null
+++ b/cmd/mesh-controller/generation_test.go
@@ -0,0 +1,107 @@
+package main
+
+import (
+	"encoding/json"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/novox/mesh-controller/internal/inventory"
+)
+
+// The assignment generation a declaration was composed from (novox/hq issue 234).
+
+func bodyKeys(t *testing.T, s sendable) map[string]any {
+	t.Helper()
+	raw, err := s.Body()
+	if err != nil {
+		t.Fatal(err)
+	}
+	var keys map[string]any
+	if err := json.Unmarshal(raw, &keys); err != nil {
+		t.Fatal(err)
+	}
+	return keys
+}
+
+// **The generation goes on the wire only to a machine whose node-engine said it reads one**: an older
+// node-engine decodes strictly and refuses an unknown key, whole. And the put-back mark only with it.
+func TestTheGenerationIsSentOnlyToAMachineThatReadsOne(t *testing.T) {
+	resources := []map[string]any{{"id": "a", "type": "file", "path": "/etc/a", "content": "x\n"}}
+	reads := order{sequence: 12, epoch: 57, generation: 40, readsGeneration: true, acting: 57, putBack: true}
+	var told sendable
+	told.Resources = resources
+	reads.stamp(&told)
+	keys := bodyKeys(t, told)
+	if keys["generation"] != float64(40) || keys["put_back"] != true || keys["sequence"] != float64(12) {
+		t.Fatalf("a machine that reads a generation was sent %v", keys)
+	}
+	if told.composedFrom != 40 || told.actingEpoch != 57 {
+		t.Errorf("the send does not keep what it was composed from for its record: %+v", told)
+	}
+
+	older := order{sequence: 12, epoch: 57, generation: 40, readsGeneration: false, acting: 57, putBack: true}
+	var untold sendable
+	untold.Resources = resources
+	older.stamp(&untold)
+	keys = bodyKeys(t, untold)
+	if _, there := keys["generation"]; there {
+		t.Fatalf("a machine whose node-engine never said it reads a generation was sent one: %v", keys)
+	}
+	if _, there := keys["put_back"]; there {
+		t.Fatalf("a machine whose node-engine never said it reads a generation was sent a put-back mark: %v", keys)
+	}
+	if untold.composedFrom != 40 {
+		t.Errorf("the generation it was composed from is recorded whether or not it was sent: %+v", untold)
+	}
+
+	// An ordinary send carries no put-back mark at all: the body is what it was apart from the generation.
+	var ordinary sendable
+	ordinary.Resources = resources
+	ordinaryOrder := reads
+	ordinaryOrder.putBack = false
+	ordinaryOrder.stamp(&ordinary)
+	if _, there := bodyKeys(t, ordinary)["put_back"]; there {
+		t.Fatal("an ordinary send says it is a put-back")
+	}
+}
+
+// **The sender is named**: the caller of the seat call when there is one, else the shell's account, and the
+// process and build that composed it.
+func TestASendNamesItsSender(t *testing.T) {
+	said := senderOf("g14.node-tools, through the mesh-controller seat")
+	if !strings.Contains(said, "g14.node-tools") || !strings.Contains(said, "pid ") || !strings.Contains(said, "build ") {
+		t.Fatalf("the sender reads %q", said)
+	}
+}
+
+// refusedSend is a send a machine refused for its generation at a moment.
+func refusedSend(at time.Time) inventory.Send {
+	return inventory.Send{NodeName: "anchor", Sequence: 12, Epoch: 57, Generation: 38, RefusedApplied: 40,
+		Sender:  "a one-shot push by jochen at a shell on anchor (pid 4242 on anchor, build 2026.10.11)",
+		Modules: []string{"docker"}, SentAt: at.Add(-time.Second), RefusedAt: &at}
+}
+
+// **A refused send is raised naming its sender** (novox/hq issue 234): who sent it, from which generation,
+// against which the machine applied, and its sequence — the facts that took a morning to look for.
+func TestARefusedSendIsRaisedNamingItsSender(t *testing.T) {
+	now := time.Date(2026, 10, 11, 12, 0, 0, 0, time.UTC)
+	f := calm(now)
+	f.refusedSends = []inventory.Send{refusedSend(now.Add(-time.Minute))}
+	got := watchGenerationRefusals(f)
+	if len(got) != 1 {
+		t.Fatalf("%+v", got)
+	}
+	o := got[0]
+	if o.Key() != "machine.anchor.older-generation" || o.Machine != "anchor" {
+		t.Errorf("raised as %s about %q", o.Key(), o.Machine)
+	}
+	for _, want := range []string{"a one-shot push by jochen", "generation 38", "generation 40", "sequence 12"} {
+		if !strings.Contains(o.Summary, want) {
+			t.Errorf("the summary does not say %q: %s", want, o.Summary)
+		}
+	}
+	if o.Headline == "" || o.Explanation == "" || o.Resolved == "" {
+		t.Errorf("the condition is not worded for the operator: %+v", o)
+	}
+}
diff --git a/cmd/mesh-controller/held_back_test.go b/cmd/mesh-controller/held_back_test.go
index bcb0fe94..f9d2ba06 100644
--- a/cmd/mesh-controller/held_back_test.go
+++ b/cmd/mesh-controller/held_back_test.go
@@ -128,7 +128,7 @@ func (r *recordedDelivery) grant(context.Context, []readyNode) error { return ni
 
 func (r *recordedDelivery) declare(ctx context.Context, s readyNode, body []byte) (string, error) {
 	r.declared = append(r.declared, s.node)
-	return recordSent(ctx, r.inv, s.node, body, s.declared.Builds, s.declared.Epoch)
+	return recordSent(ctx, r.inv, s.node, body, s.declared.Builds, s.declared.Epoch, sentRecordOf(ctx, s.declared))
 }
 
 // aResolver is a module built from a repository, at a commit, with something on the machine that
diff --git a/cmd/mesh-controller/issue_204_test.go b/cmd/mesh-controller/issue_204_test.go
index feda54d8..1779292a 100644
--- a/cmd/mesh-controller/issue_204_test.go
+++ b/cmd/mesh-controller/issue_204_test.go
@@ -77,7 +77,7 @@ func TestASendIsRecordedEvenWhenTheSenderIsBeingCancelled(t *testing.T) {
 	}
 	cancel() // the sender is going away: its context is cancelled between the send and the record
 	body := []byte(`{"declaration":1,"resources":[]}`)
-	digest, err := recordSent(ctx, inv, "anchor", body, nil, 0)
+	digest, err := recordSent(ctx, inv, "anchor", body, nil, 0, sentRecord{sender: "a test"})
 	if err != nil {
 		// NodeByName on the cancelled context may itself refuse; the record must still be possible
 		// through the detached context, so look the node up again on a live one.
diff --git a/cmd/mesh-controller/plan.go b/cmd/mesh-controller/plan.go
index 82f0fbb4..2ec829b1 100644
--- a/cmd/mesh-controller/plan.go
+++ b/cmd/mesh-controller/plan.go
@@ -420,7 +420,8 @@ func declarationWith(ctx context.Context, open *stores, node string,
 	out := sendable{Resources: composed.Resources, Adoption: adoption,
 		Received: composed.Received, Mesh: with.Mesh, BusUsers: with.BusUsers,
 		LeftOut: sortedKeysOf(composed.LeftOut), leftOutWhy: composed.LeftOut, withheld: with.Withheld,
-		unbound: with.Unbound, foreseen: composed.Foreseen, unplaced: composed.Unplaced}
+		unbound: with.Unbound, foreseen: composed.Foreseen, unplaced: composed.Unplaced,
+		modules: namedModules(plan, composed.LeftOut)}
 	// And which build of each module it carries, for the send to record (novox/hq issue 259, ADR
 	// 0221). Read only on the send path: a question about what would be sent records nothing.
 	if choosing == Allocating {
@@ -1290,6 +1291,11 @@ func planCommand(ctx context.Context, args []string) error {
 		return nil
 	}
 
+	// What the machine was last told, by whom and from which assignment generation (novox/hq issue 234),
+	// beside what it would be told now. A record that cannot be read is said, not taken for none.
+	if err := writeLastSend(ctx, os.Stdout, open.inventory, args[0]); err != nil {
+		fmt.Printf("what %s was last sent could not be read: %v\n", args[0], err)
+	}
 	// Which modules a push would leave out, and why — said before the plan, since the plan is of
 	// what the machine would be told (novox/hq ADR 0163, rule 6). Judged, never composed: `plan`
 	// without --json allocates nothing.
diff --git a/cmd/mesh-controller/push.go b/cmd/mesh-controller/push.go
index 9779b442..be33434b 100644
--- a/cmd/mesh-controller/push.go
+++ b/cmd/mesh-controller/push.go
@@ -356,10 +356,18 @@ func declare(ctx context.Context, args []string) error {
 	// the mesh did not compose it, so a push that does not name this machine treats it as held.
 	// The epoch it carried, if a person wrote one in, is what the machine heard.
 	var carried struct {
-		Epoch uint64 `json:"epoch"`
+		Epoch      uint64 `json:"epoch"`
+		Sequence   int64  `json:"sequence"`
+		Generation int64  `json:"generation"`
+		PutBack    bool   `json:"put_back"`
 	}
 	_ = json.Unmarshal(raw, &carried)
-	if _, err := recordSent(ctx, inv, node, raw, nil, carried.Epoch); err != nil {
+	// And recorded as every send is (novox/hq issue 234): by hand, from what it carried; the modules it
+	// named are not known, since the mesh did not compose it.
+	if _, err := recordSent(ctx, inv, node, raw, nil, carried.Epoch, sentRecord{sequence: carried.Sequence,
+		epoch: carried.Epoch, generation: carried.Generation, putBack: carried.PutBack,
+		toldGeneration: carried.Generation, toldPutBack: carried.PutBack,
+		sender: senderOf(callerOf(ctx)) + ", a declaration sent by hand"}); err != nil {
 		return err
 	}
 	fmt.Printf("sent %s a signed declaration (%d bytes)\n", node, len(raw))
@@ -798,7 +806,7 @@ func composeEach(names []string, allot func(node string) (order, error),
 			refusals = append(refusals, fmt.Sprintf("%s:\n%v", name, err))
 			continue
 		}
-		declared.Sequence, declared.Epoch = numbered.sequence, numbered.epoch
+		numbered.stamp(&declared)
 		if len(declared.Resources) == 0 {
 			// Sent, not skipped (novox/hq issue 127). A node whose declaration composes to
 			// nothing may have HELD something before — the broker opening a placement gave it,
@@ -1016,7 +1024,8 @@ func (b overTheBus) declare(ctx context.Context, s readyNode, body []byte) (stri
 	}
 	// After it is away, not before. A digest recorded for something that failed to send would make
 	// the machine look current for a declaration it never received.
-	digest, err := recordSent(ctx, b.open.inventory, s.node, body, s.declared.Builds, s.declared.Epoch)
+	digest, err := recordSent(ctx, b.open.inventory, s.node, body, s.declared.Builds, s.declared.Epoch,
+		sentRecordOf(ctx, s.declared))
 	if err != nil {
 		return "", err
 	}
@@ -1228,7 +1237,7 @@ func sendToEach(ctx context.Context, open *stores, names []string) ([]string, er
 			refusals = append(refusals, fmt.Sprintf("%s:\n%v", name, err))
 			continue
 		}
-		declared.Sequence, declared.Epoch = numbered.sequence, numbered.epoch
+		numbered.stamp(&declared)
 		reportLeftOut(name, declared)
 		sending = append(sending, readyNode{name, declared})
 	}
@@ -1393,6 +1402,11 @@ func wouldSendFrom(ctx context.Context, open *stores,
 		if declared.Epoch, err = open.inventory.SentEpoch(ctx, n.ID); err != nil {
 			return nil, err
 		}
+		// And the generation and put-back mark it was last sent, for the same reason (novox/hq issue 234):
+		// an assignment elsewhere in the mesh is not a change of this machine.
+		if declared.Generation, declared.PutBack, err = open.inventory.SentGeneration(ctx, n.ID); err != nil {
+			return nil, err
+		}
 		body, err := declared.Body()
 		if err != nil {
 			return nil, err
@@ -1531,6 +1545,14 @@ var epochForActs = func(ctx context.Context) (uint64, error) { return theLease.e
 type order struct {
 	sequence int64
 	epoch    uint64
+	// generation is the assignment generation read before the composition, and readsGeneration whether the
+	// machine's node-engine said it reads one (novox/hq issue 234); acting is the lease epoch the sender acts
+	// under, whether or not the machine is sent it — both kept for the record of the send.
+	generation      int64
+	readsGeneration bool
+	acting          uint64
+	// putBack is a gate's put-back (sendScope.putBack), read from the send's context.
+	putBack bool
 }
 
 // allot takes the next sequence for a machine — the number its next declaration carries — under the
@@ -1544,6 +1566,7 @@ func allot(ctx context.Context, inv *inventory.Inventory, node string) (order, e
 	if err != nil {
 		return order{}, err
 	}
+	acting := epoch
 	if epoch > 0 {
 		reads, err := inv.ReadsEpoch(ctx, record.ID)
 		if err != nil {
@@ -1553,11 +1576,24 @@ func allot(ctx context.Context, inv *inventory.Inventory, node string) (order, e
 			epoch = 0
 		}
 	}
+	// **The generation is read here, before the composition reads a single assignment** (novox/hq issue
+	// 234). A generation only grows, so one read before is never newer than the view composed after it:
+	// the declaration may claim a generation older than its content, never newer — and a claim newer than
+	// the content is exactly the stale send the machine must be able to refuse.
+	generation, err := inv.AssignmentGeneration(ctx)
+	if err != nil {
+		return order{}, err
+	}
+	readsGeneration, err := inv.ReadsGeneration(ctx, record.ID)
+	if err != nil {
+		return order{}, err
+	}
 	seq, err := inv.NextSequence(ctx, record.ID)
 	if err != nil {
 		return order{}, err
 	}
-	return order{sequence: seq, epoch: epoch}, nil
+	return order{sequence: seq, epoch: epoch, generation: generation, readsGeneration: readsGeneration,
+		acting: acting, putBack: scopeOf(ctx).putBack}, nil
 }
 
 // recordSent writes down what a machine was just sent, and returns the digest.
@@ -1572,7 +1608,7 @@ func allot(ctx context.Context, inv *inventory.Inventory, node string) (order, e
 // And the build of each module it carried (novox/hq issue 259, ADR 0221), nil when that is not known:
 // what tells a machine held back by a policy or a plan from one a push left behind.
 func recordSent(ctx context.Context, inv *inventory.Inventory, node string, body []byte,
-	builds map[string]string, epoch uint64) (string, error) {
+	builds map[string]string, epoch uint64, sent sentRecord) (string, error) {
 	kept, cancel := context.WithTimeout(context.WithoutCancel(ctx), 10*time.Second)
 	defer cancel()
 	record, err := inv.NodeByName(kept, node)
@@ -1583,6 +1619,14 @@ func recordSent(ctx context.Context, inv *inventory.Inventory, node string, body
 	if err := inv.RecordSentUnder(kept, record.ID, digest, builds, epoch); err != nil {
 		return "", err
 	}
+	// And the send itself, who sent it and from which generation (novox/hq issue 234): what the machine
+	// was last told, by whom, is read back from here — and what the would-send is stamped with.
+	if err := inv.RecordSend(kept, inventory.Send{Node: record.ID, Sequence: sent.sequence,
+		Epoch: int64(sent.epoch), Sender: sent.sender, Generation: sent.generation, PutBack: sent.putBack,
+		ToldGeneration: sent.toldGeneration, ToldPutBack: sent.toldPutBack, Digest: digest,
+		Modules: sent.modules}); err != nil {
+		return "", fmt.Errorf("%s was sent its declaration, and the send could not be recorded: %w", node, err)
+	}
 	// And what it was, summarised, so the next push can be compared with it (novox/hq ADR 0217).
 	// Never a reason to fail a send that is already away: a summary that cannot be kept means the
 	// next comparison has nothing to hold against, which is how every machine starts.
diff --git a/cmd/mesh-controller/release.go b/cmd/mesh-controller/release.go
index 56b702c8..31c1ef87 100644
--- a/cmd/mesh-controller/release.go
+++ b/cmd/mesh-controller/release.go
@@ -50,6 +50,9 @@ type sendScope struct {
 	modules map[string]bool
 	// person is a person's act: it carries what it carries.
 	person bool
+	// putBack is a gate putting machines back after a failed send (novox/hq issue 234): its declarations
+	// say so, and a machine does not refuse them for the generation they carry.
+	putBack bool
 }
 
 type sendScopeKey struct{}
diff --git a/cmd/mesh-controller/sendable.go b/cmd/mesh-controller/sendable.go
index 2311522a..cbc89943 100644
--- a/cmd/mesh-controller/sendable.go
+++ b/cmd/mesh-controller/sendable.go
@@ -27,6 +27,25 @@ type sendable struct {
 	// said it reads one is sent none, because an older node-engine refuses a key it does not know, whole
 	// (link/order.go, the contract).
 	Epoch uint64
+	// Generation is the assignment generation it was composed from (novox/hq issue 234): a machine that
+	// applied a later one refuses it, so a send composed from a view of the assignments the mesh has moved
+	// past cannot undeclare what is still assigned. Zero is not sent at all — every machine whose
+	// node-engine has not said it reads one is sent none, for the reason the epoch is not (an older
+	// node-engine refuses a key it does not know, whole).
+	Generation int64
+	// PutBack marks a gate's put-back (novox/hq issue 234): it carries the generation of what it puts
+	// back and is not refused for it. Sent only beside a generation.
+	PutBack bool
+	// composedFrom is the generation read before this declaration was composed, and actingEpoch the
+	// lease epoch its sender acted under — whether or not the machine is sent either — for the record of
+	// the send; never on the wire.
+	composedFrom int64
+	actingEpoch  uint64
+	// putBackSend is whether a gate sent it to put the machine back, for the record; PutBack is the mark
+	// on the wire, only beside a generation.
+	putBackSend bool
+	// modules are the modules this declaration names, for the record of the send; never on the wire.
+	modules []string
 	// Adoption is nil for a converged node, and then the body is byte for byte what it was before
 	// adoption existed: an older host parses the envelope strictly and would refuse the key.
 	Adoption *adoptionEnvelope
@@ -94,6 +113,12 @@ func (s sendable) Body() ([]byte, error) {
 	if len(s.LeftOut) > 0 {
 		envelope["left_out"] = s.LeftOut
 	}
+	if s.Generation > 0 {
+		envelope["generation"] = s.Generation
+		if s.PutBack {
+			envelope["put_back"] = true
+		}
+	}
 	// An empty declaration is deliberate here — the node owns nothing the mesh put there
 	// (novox/hq issue 127) — and the host refuses an empty body unless it is told the emptiness
 	// is meant, so a truncated or mis-composed body is never mistaken for "own nothing".
diff --git a/cmd/mesh-controller/signals.go b/cmd/mesh-controller/signals.go
index ab3e8a93..34a6781c 100644
--- a/cmd/mesh-controller/signals.go
+++ b/cmd/mesh-controller/signals.go
@@ -226,6 +226,20 @@ var signalsTable = []signalRow{
 		newest: func(f *signalFacts) time.Time {
 			return newestOf(f.batches, func(b batchFacts) time.Time { return b.closed })
 		}},
+	{Row: "S20", Signal: "a send refused for the assignment generation it was composed from",
+		Emitter: "node-engine", Trigger: "each refusal (novox/hq issue 234)",
+		Bound: "none: raised at the first refusal, naming its sender, the generation it came from and the one the " +
+			"machine applied; cleared an hour after the last",
+		Kind: kindOlderGeneration, Severity: conditions.Warning, Phase: 2,
+		needs: func(f *signalFacts) error { return f.refusedSendsErr }, watch: watchGenerationRefusals,
+		newest: func(f *signalFacts) time.Time {
+			return newestOf(f.refusedSends, func(s inventory.Send) time.Time {
+				if s.RefusedAt == nil {
+					return time.Time{}
+				}
+				return *s.RefusedAt
+			})
+		}},
 	{Row: "S17", Signal: "a send held for the bus's planned step is told to a person", Emitter: "controller's plan",
 		Trigger: "each send refused because it would replace the bus outside its step (novox/hq issue 336)",
 		Bound: "none: raised at the first refusal, for the operator, naming what waits, the bus build from and to, " +
diff --git a/cmd/mesh-controller/signals_test.go b/cmd/mesh-controller/signals_test.go
index c69a9d02..9abf6ce8 100644
--- a/cmd/mesh-controller/signals_test.go
+++ b/cmd/mesh-controller/signals_test.go
@@ -178,6 +178,14 @@ var suppressions = map[string]suppression{
 					commit: "c0ffee001122", modules: []string{"app"}, since: f.now.Add(-time.Second)}}}
 		},
 	},
+	// A send refused by its machine for the generation it was composed from (novox/hq issue 234): said at
+	// once, naming its sender, for an hour after. Inside: the last such refusal was more than an hour ago.
+	"S20": {
+		inside: func(f *signalFacts) {
+			f.refusedSends = []inventory.Send{refusedSend(f.now.Add(-61 * time.Minute))}
+		},
+		past: func(f *signalFacts) { f.refusedSends = []inventory.Send{refusedSend(f.now.Add(-time.Second))} },
+	},
 	// Twice by hand within a fortnight is a healer wanted; once, or the first of two a day too old, is not.
 	"S15": {
 		inside: func(f *signalFacts) {
diff --git a/cmd/mesh-controller/status_summary.go b/cmd/mesh-controller/status_summary.go
index 7974abd4..a81a0b8e 100644
--- a/cmd/mesh-controller/status_summary.go
+++ b/cmd/mesh-controller/status_summary.go
@@ -196,6 +196,11 @@ func (l nudgingListener) Heard(ctx context.Context, report link.Report) (bool, e
 	if report.Ordered() {
 		link.StaleRefusals.Lifetime(report.Node, report.RefusedOlder, now)
 	}
+	// A send refused for the generation it was composed from is kept on the send it refused, so S20 names
+	// its sender (novox/hq issue 234).
+	if report.OlderGeneration != nil {
+		heardGenerationRefusal(ctx, l.Enrolment.Inventory, report)
+	}
 	// What the machine's witnesses put back and stand by (novox/hq ADR 0236): read by the gate and its
 	// probe. Only from an account of the machine — not a word that a declaration was set aside, nor a rekey.
 	if report.Superseded == "" && report.Rekey == nil && report.Node != "" {
diff --git a/cmd/mesh-controller/watchdogs.go b/cmd/mesh-controller/watchdogs.go
index 35c2c951..7ccb352d 100644
--- a/cmd/mesh-controller/watchdogs.go
+++ b/cmd/mesh-controller/watchdogs.go
@@ -55,6 +55,10 @@ type signalFacts struct {
 	waits []waitFacts
 	// batches are the batches not yet cut (S18, S19, novox/hq ADR 0276).
 	batches []batchFacts
+	// refusedSends are the sends a machine refused within the hour for the generation they were composed
+	// from, each naming its sender (S20, novox/hq issue 234).
+	refusedSends    []inventory.Send
+	refusedSendsErr error
 
 	loop    loopFacts
 	loopErr error
@@ -364,6 +368,7 @@ func (w *watchdogs) gather(ctx context.Context) *signalFacts {
 		}
 	}
 	f.handActs, f.handActsErr = w.gatherHandActs(ctx, now)
+	f.refusedSends, f.refusedSendsErr = inv.RefusedSendsSince(ctx, now.Add(-generationRefusalsSaid))
 	f.facts.taken, _, f.facts.began, f.facts.err = exportedFacts.last()
 	return f
 }
diff --git a/internal/inventory/migrations/0094-a-declaration-says-the-generation-it-came-from.sql b/internal/inventory/migrations/0094-a-declaration-says-the-generation-it-came-from.sql
new file mode 100644
index 00000000..07a182d3
--- /dev/null
+++ b/internal/inventory/migrations/0094-a-declaration-says-the-generation-it-came-from.sql
@@ -0,0 +1,64 @@
+-- A declaration says the assignment generation it was composed from, and every send is recorded
+-- (novox/hq issue 234).
+--
+-- On 2026-10-04 a declaration newer in sequence than every other named four fewer modules than the
+-- assignments held, and the machine undeclared all four. The sequence orders arrival; it cannot tell a
+-- later send that carries an older view of the assignments. And nothing the mesh kept said which process
+-- sent it, from what view: the node row holds only the digest of the last send.
+
+-- The assignment generation: one counter for the mesh, raised in the same transaction as every change to
+-- what is assigned where. A trigger, not a line in each writer: an assignment is also taken by a node's
+-- removal (on delete cascade) and renamed with its module (on update cascade), which no writer in Go
+-- sees, and a rule kept only by the writers that remember it is the rule this issue found broken. Seeded
+-- at 1, so every declaration composed after this claims a generation and none claims zero ("none").
+create table assignment_generation (
+    one        boolean primary key default true check (one),
+    generation bigint  not null
+);
+insert into assignment_generation (one, generation) values (true, 1);
+
+create function raise_assignment_generation() returns trigger language plpgsql as $$
+begin
+    update assignment_generation set generation = generation + 1;
+    return null;
+end
+$$;
+
+-- Per row, so a statement that changes nothing (an assignment repeated, `on conflict do nothing`) raises
+-- nothing; a statement that changes several raises once per row, which only ever moves it forward.
+create trigger assignment_generation_raised
+    after insert or update or delete on assignment
+    for each row execute function raise_assignment_generation();
+
+-- What a machine was last sent of it: the generation, and whether that send was a gate's put-back, so
+-- what the mesh WOULD send is stamped the same way and reads as byte for byte what it DID send when
+-- nothing else changed (as sent_epoch, migration 0068). Null and false for a send without.
+alter table node add column sent_generation bigint;
+alter table node add column sent_put_back boolean not null default false;
+-- Whether the machine's node-engine said it reads a generation (its reports' `reads_generation`): until
+-- it has, it is sent none, because an older node-engine refuses a key it does not know, whole.
+alter table node add column reads_generation boolean not null default false;
+
+-- Every send: the machine, its sequence, who sent it — the lease epoch the sender acted under and the
+-- caller, process and build — the generation it was composed from, whether it was a put-back, its
+-- digest and the modules it named. Written after the declaration is away, as the node row's record is.
+-- A refusal by the machine of a send for its generation is kept on the send it refused, so the
+-- condition it raises names the sender from here. The newest 200 per machine are kept.
+create table declaration_send (
+    id           bigserial   primary key,
+    node         uuid        not null references node (id) on delete cascade,
+    sequence     bigint,
+    epoch        bigint,
+    sender       text        not null,
+    generation   bigint,
+    put_back     boolean     not null default false,
+    digest       text        not null,
+    modules      text[]      not null default '{}',
+    sent_at      timestamptz not null default now(),
+    refused_at   timestamptz,
+    -- refused_applied is the generation the machine said it had applied when it refused this send.
+    refused_applied bigint
+);
+create index declaration_send_node on declaration_send (node, id desc);
+create index declaration_send_sequence on declaration_send (node, sequence);
+create index declaration_send_refused on declaration_send (refused_at) where refused_at is not null;
diff --git a/internal/inventory/sends.go b/internal/inventory/sends.go
new file mode 100644
index 00000000..085a2ac9
--- /dev/null
+++ b/internal/inventory/sends.go
@@ -0,0 +1,202 @@
+package inventory
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"github.com/jackc/pgx/v5"
+)
+
+// The assignment generation and the record of every send (novox/hq issue 234, migration 0094).
+//
+// A declaration carries the generation of the assignments it was composed from, and a machine refuses one
+// composed from an older generation than it applied — the sequence orders arrival and cannot tell a later
+// send carrying an older view. And every send is written down with who sent it, from which generation and
+// naming which modules, so what a machine was last told, by whom, is read back rather than guessed at.
+
+// sendsKept is how many sends are kept per machine: the newest. Enough to read back a morning of pushes
+// on a busy machine; the record is for finding who sent what, not an archive.
+const sendsKept = 200
+
+// AssignmentGeneration is the mesh's assignment generation now: raised by the store itself in the same
+// transaction as every change to what is assigned where (a trigger on the assignment table).
+func (i *Inventory) AssignmentGeneration(ctx context.Context) (int64, error) {
+	var g int64
+	if err := i.store.Pool().QueryRow(ctx, `select generation from assignment_generation`).Scan(&g); err != nil {
+		return 0, fmt.Errorf("reading the assignment generation: %w", err)
+	}
+	return g, nil
+}
+
+// RaiseAssignmentGeneration raises the generation past one a machine applied, and answers it: one more
+// than that, or what it already was when it is past it. It never lowers it.
+//
+// For one case only: a machine refused a send composed from the generation the mesh holds now, so the
+// machine applied a higher one than the mesh's counter — a store put back from a backup. Every send after
+// would be refused for ever; raised past it, the next send carries a generation the machine takes, composed
+// from the assignments the store holds now. A stale sender never meets this: its generation is below the
+// counter, and the counter is not touched for it.
+func (i *Inventory) RaiseAssignmentGeneration(ctx context.Context, past int64) (int64, error) {
+	var g int64
+	err := i.store.Pool().QueryRow(ctx,
+		`update assignment_generation set generation = greatest(generation, $1 + 1) returning generation`, past).Scan(&g)
+	if err != nil {
+		return 0, fmt.Errorf("raising the assignment generation past %d: %w", past, err)
+	}
+	return g, nil
+}
+
+// SentGeneration is the generation a machine was last sent and whether that send was a put-back, by its
+// id; zero for one sent without. What the mesh WOULD send is stamped with these, so it reads as byte for
+// byte what it DID send when nothing else changed.
+func (i *Inventory) SentGeneration(ctx context.Context, id string) (int64, bool, error) {
+	var g *int64
+	var putBack bool
+	if err := i.store.Pool().QueryRow(ctx, `select sent_generation, sent_put_back from node where id = $1`, id).
+		Scan(&g, &putBack); err != nil {
+		return 0, false, fmt.Errorf("reading the generation %s was last sent: %w", id, err)
+	}
+	if g == nil {
+		return 0, putBack, nil
+	}
+	return *g, putBack, nil
+}
+
+// ReadsGeneration says a machine's node-engine said it reads a generation in a declaration, by its id.
+func (i *Inventory) ReadsGeneration(ctx context.Context, id string) (bool, error) {
+	var reads bool
+	if err := i.store.Pool().QueryRow(ctx, `select reads_generation from node where id = $1`, id).Scan(&reads); err != nil {
+		return false, fmt.Errorf("reading whether %s reads a generation: %w", id, err)
+	}
+	return reads, nil
+}
+
+// RecordReadsGeneration keeps what a machine's latest report said of reading a generation.
+func (i *Inventory) RecordReadsGeneration(ctx context.Context, id string, reads bool) error {
+	_, err := i.store.Pool().Exec(ctx, `update node set reads_generation = $2 where id = $1`, id, reads)
+	return err
+}
+
+// Send is one declaration sent to a machine, as the mesh records it.
+type Send struct {
+	// Node is the machine's id; NodeName its name, filled where it is read back.
+	Node     string
+	NodeName string
+	Sequence int64
+	// Epoch is the lease epoch its sender acted under, zero for one that acted under none.
+	Epoch int64
+	// Sender is who sent it, in words: the caller, and the process and build that composed it.
+	Sender string
+	// Generation is the assignment generation it was composed from, zero when not known; PutBack whether a
+	// gate sent it to put the machine back.
+	Generation int64
+	PutBack    bool
+	// ToldGeneration and ToldPutBack are what the machine was told of them on the wire: zero and false for a
+	// machine whose node-engine has not said it reads a generation. What the would-send is stamped with.
+	ToldGeneration int64
+	ToldPutBack    bool
+	Digest         string
+	// Modules are the modules it named.
+	Modules []string
+	SentAt  time.Time
+	// RefusedAt is when the machine refused it for its generation, nil when it did not; RefusedApplied the
+	// generation the machine said it had applied then.
+	RefusedAt      *time.Time
+	RefusedApplied int64
+}
+
+// RecordSend writes one send down, and what the machine was last sent of its generation, in one
+// transaction; the oldest beyond the newest 200 for the machine are let go.
+func (i *Inventory) RecordSend(ctx context.Context, s Send) error {
+	tx, err := i.store.Pool().Begin(ctx)
+	if err != nil {
+		return err
+	}
+	defer func() { _ = tx.Rollback(ctx) }()
+	if _, err := tx.Exec(ctx, `update node set sent_generation = $2, sent_put_back = $3 where id = $1`,
+		s.Node, nullIfZero(s.ToldGeneration), s.ToldPutBack); err != nil {
+		return err
+	}
+	modules := s.Modules
+	if modules == nil {
+		modules = []string{}
+	}
+	if _, err := tx.Exec(ctx,
+		`insert into declaration_send (node, sequence, epoch, sender, generation, put_back, digest, modules)
+		 values ($1, $2, $3, $4, $5, $6, $7, $8)`,
+		s.Node, nullIfZero(s.Sequence), nullIfZero(s.Epoch), s.Sender, nullIfZero(s.Generation), s.PutBack,
+		s.Digest, modules); err != nil {
+		return err
+	}
+	if _, err := tx.Exec(ctx,
+		`delete from declaration_send where node = $1 and id not in
+		   (select id from declaration_send where node = $1 order by id desc limit $2)`, s.Node, sendsKept); err != nil {
+		return err
+	}
+	return tx.Commit(ctx)
+}
+
+// sendColumns are a send's columns as scanSends reads them.
+const sendColumns = `s.node, n.name, coalesce(s.sequence, 0), coalesce(s.epoch, 0), s.sender, coalesce(s.generation, 0),
+	s.put_back, s.digest, s.modules, s.sent_at, s.refused_at, coalesce(s.refused_applied, 0)`
+
+func scanSends(rows pgx.Rows) ([]Send, error) {
+	defer rows.Close()
+	var out []Send
+	for rows.Next() {
+		var s Send
+		if err := rows.Scan(&s.Node, &s.NodeName, &s.Sequence, &s.Epoch, &s.Sender, &s.Generation, &s.PutBack,
+			&s.Digest, &s.Modules, &s.SentAt, &s.RefusedAt, &s.RefusedApplied); err != nil {
+			return nil, err
+		}
+		out = append(out, s)
+	}
+	return out, rows.Err()
+}
+
+// LastSend is the last declaration a machine was sent, by its name; false when none was recorded.
+func (i *Inventory) LastSend(ctx context.Context, name string) (Send, bool, error) {
+	rows, err := i.store.Pool().Query(ctx, `select `+sendColumns+`
+		  from declaration_send s join node n on n.id = s.node
+		 where n.name = $1 order by s.id desc limit 1`, name)
+	if err != nil {
+		return Send{}, false, err
+	}
+	sends, err := scanSends(rows)
+	if err != nil || len(sends) == 0 {
+		return Send{}, false, err
+	}
+	return sends[0], true, nil
+}
+
+// RefusedSend keeps a machine's refusal of the send of a sequence for the generation it came from, and
+// answers that send, sender and all; false when no send of that sequence was recorded — sent before the
+// record, or by a hand the mesh did not see. The newest of that sequence when there are several: a
+// declaration a person sent by hand may repeat one.
+func (i *Inventory) RefusedSend(ctx context.Context, node string, sequence, applied int64) (Send, bool, error) {
+	rows, err := i.store.Pool().Query(ctx, `with refused as (
+		update declaration_send set refused_at = now(), refused_applied = $3
+		 where id = (select id from declaration_send where node = $1 and sequence = $2 order by id desc limit 1)
+		returning *)
+		select `+sendColumns+` from refused s join node n on n.id = s.node`, node, sequence, applied)
+	if err != nil {
+		return Send{}, false, err
+	}
+	sends, err := scanSends(rows)
+	if err != nil || len(sends) == 0 {
+		return Send{}, false, err
+	}
+	return sends[0], true, nil
+}
+
+// RefusedSendsSince is every send refused for its generation since a moment, newest first.
+func (i *Inventory) RefusedSendsSince(ctx context.Context, since time.Time) ([]Send, error) {
+	rows, err := i.store.Pool().Query(ctx, `select `+sendColumns+`
+		  from declaration_send s join node n on n.id = s.node
+		 where s.refused_at >= $1 order by s.refused_at desc`, since)
+	if err != nil {
+		return nil, err
+	}
+	return scanSends(rows)
+}
diff --git a/internal/inventory/sends_test.go b/internal/inventory/sends_test.go
new file mode 100644
index 00000000..9f5dfe6b
--- /dev/null
+++ b/internal/inventory/sends_test.go
@@ -0,0 +1,138 @@
+package inventory
+
+import (
+	"slices"
+	"testing"
+	"time"
+)
+
+// The assignment generation and the record of every send (novox/hq issue 234). On 2026-10-04 a declaration
+// newer in sequence than every other named four fewer modules than the assignments held, a machine applied
+// it, and nothing the mesh kept could say who sent it or from what view.
+
+func generationNow(t *testing.T, inv *Inventory) int64 {
+	t.Helper()
+	g, err := inv.AssignmentGeneration(t.Context())
+	if err != nil {
+		t.Fatal(err)
+	}
+	return g
+}
+
+// **Every change to what is assigned where raises the generation, in its own transaction** — an
+// assignment, an unassignment, and one taken by the machine's removal, which no writer in Go makes — and
+// a repeated assignment, which changes nothing, does not.
+func TestEveryAssignmentChangeRaisesTheGeneration(t *testing.T) {
+	inv, node := aNodeWithModules(t, "postgres", "web")
+	ctx := t.Context()
+	start := generationNow(t, inv)
+	if start < 1 {
+		t.Fatalf("the generation starts at %d; zero is \"none claimed\" on the wire", start)
+	}
+	if _, err := inv.Assign(ctx, node, "postgres"); err != nil {
+		t.Fatal(err)
+	}
+	assigned := generationNow(t, inv)
+	if assigned <= start {
+		t.Fatalf("an assignment left the generation at %d", assigned)
+	}
+	if _, err := inv.Assign(ctx, node, "postgres"); err != nil {
+		t.Fatal(err)
+	}
+	if again := generationNow(t, inv); again != assigned {
+		t.Errorf("an assignment repeated, which changed nothing, moved the generation from %d to %d", assigned, again)
+	}
+	if err := inv.Unassign(ctx, node, "postgres"); err != nil {
+		t.Fatal(err)
+	}
+	unassigned := generationNow(t, inv)
+	if unassigned <= assigned {
+		t.Fatalf("an unassignment left the generation at %d", unassigned)
+	}
+	if _, err := inv.Assign(ctx, node, "web"); err != nil {
+		t.Fatal(err)
+	}
+	before := generationNow(t, inv)
+	if _, err := inv.RemoveNodeForTest(ctx, node); err != nil {
+		t.Fatal(err)
+	}
+	if removed := generationNow(t, inv); removed <= before {
+		t.Errorf("a machine's removal took its assignments and left the generation at %d", removed)
+	}
+}
+
+// **The generation never goes down, and is raised past what a machine applied when the mesh's own counter
+// is behind it** — a store put back from a backup — so the next send is not refused for ever.
+func TestTheGenerationIsRaisedPastWhatAMachineApplied(t *testing.T) {
+	inv, _ := aNodeWithModules(t)
+	now := generationNow(t, inv)
+	if raised, err := inv.RaiseAssignmentGeneration(t.Context(), now+40); err != nil || raised != now+41 {
+		t.Fatalf("raised past %d to %d (%v)", now+40, raised, err)
+	}
+	if raised, err := inv.RaiseAssignmentGeneration(t.Context(), 2); err != nil || raised != now+41 {
+		t.Fatalf("a raise below the counter moved it to %d (%v)", raised, err)
+	}
+}
+
+// **Every send is recorded: its sequence, its sender, the generation it came from and the modules it
+// named** — and the machine's last send is what `plan` reads, the would-send is stamped with its
+// generation and put-back mark, and a refusal is kept on the send it refused, naming its sender.
+func TestASendIsRecordedWithItsSenderGenerationAndModules(t *testing.T) {
+	inv, node := aNodeWithModules(t)
+	ctx := t.Context()
+	record, err := inv.NodeByName(ctx, node)
+	if err != nil {
+		t.Fatal(err)
+	}
+	first := Send{Node: record.ID, Sequence: 11, Epoch: 57, Sender: "the controller's daemon (pid 7 on anchor)",
+		Generation: 40, Digest: "d11", Modules: []string{"docker", "pacman", "sudo"}}
+	if err := inv.RecordSend(ctx, first); err != nil {
+		t.Fatal(err)
+	}
+	stale := Send{Node: record.ID, Sequence: 12, Epoch: 57, Sender: "a one-shot push by jochen at a shell on anchor",
+		Generation: 38, ToldGeneration: 38, Digest: "d12", Modules: []string{"docker"}}
+	if err := inv.RecordSend(ctx, stale); err != nil {
+		t.Fatal(err)
+	}
+	last, found, err := inv.LastSend(ctx, node)
+	if err != nil || !found {
+		t.Fatalf("the last send is not kept: %v", err)
+	}
+	if last.Sequence != 12 || last.Sender != stale.Sender || last.Generation != 38 ||
+		!slices.Equal(last.Modules, []string{"docker"}) || last.SentAt.IsZero() {
+		t.Fatalf("the last send reads %+v", last)
+	}
+	generation, putBack, err := inv.SentGeneration(ctx, record.ID)
+	if err != nil || generation != 38 || putBack {
+		t.Fatalf("what the machine was last sent of it reads %d, %v (%v)", generation, putBack, err)
+	}
+
+	refused, found, err := inv.RefusedSend(ctx, record.ID, 12, 40)
+	if err != nil || !found || refused.Sender != stale.Sender || refused.RefusedApplied != 40 {
+		t.Fatalf("the refusal is not kept on the send it refused: %+v, %v, %v", refused, found, err)
+	}
+	since, err := inv.RefusedSendsSince(ctx, time.Now().Add(-time.Hour))
+	if err != nil || len(since) != 1 || since[0].NodeName != node || since[0].Sequence != 12 {
+		t.Fatalf("the refused sends within the hour read %+v (%v)", since, err)
+	}
+	if _, found, err := inv.RefusedSend(ctx, record.ID, 99, 40); err != nil || found {
+		t.Errorf("a refusal of a send never recorded was found: %v, %v", found, err)
+	}
+}
+
+// **A machine that reads a generation is recorded from its reports**, and one rolled back says so no longer.
+func TestWhetherAMachineReadsAGenerationIsItsLatestWord(t *testing.T) {
+	inv, node := aNodeWithModules(t)
+	record, err := inv.NodeByName(t.Context(), node)
+	if err != nil {
+		t.Fatal(err)
+	}
+	for _, reads := range []bool{false, true, false} {
+		if err := inv.RecordReadsGeneration(t.Context(), record.ID, reads); err != nil {
+			t.Fatal(err)
+		}
+		if got, err := inv.ReadsGeneration(t.Context(), record.ID); err != nil || got != reads {
+			t.Fatalf("recorded %v, read %v (%v)", reads, got, err)
+		}
+	}
+}
diff --git a/internal/link/enrolment.go b/internal/link/enrolment.go
index 6c3cab6b..de36001f 100644
--- a/internal/link/enrolment.go
+++ b/internal/link/enrolment.go
@@ -447,6 +447,13 @@ func (e Enrolment) Heard(ctx context.Context, report Report) (news bool, err err
 	if err := e.Inventory.RecordReadsEpoch(ctx, node.ID, report.ReadsEpoch()); err != nil {
 		return false, err
 	}
+	// And whether it reads a generation (novox/hq issue 234), the same way: only from a node-engine that
+	// orders its reports, so a one-shot report (a rekey) does not say an engine stopped reading one.
+	if report.Ordered() {
+		if err := e.Inventory.RecordReadsGeneration(ctx, node.ID, report.ReadsGeneration); err != nil {
+			return false, err
+		}
+	}
 	if report.Ordered() {
 		account := AccountOf(report)
 		news, err = e.Inventory.RecordOrderedDoing(ctx, node.ID, doing,
diff --git a/internal/link/generation_test.go b/internal/link/generation_test.go
new file mode 100644
index 00000000..7a25283b
--- /dev/null
+++ b/internal/link/generation_test.go
@@ -0,0 +1,33 @@
+package link
+
+import (
+	"encoding/json"
+	"testing"
+)
+
+// A report's word on the assignment generation (novox/hq issue 234), as mesh-host's report writes it:
+// `reads_generation` on every report of a node-engine that reads one, and `older_generation` on a refusal
+// of a declaration composed from an older generation than the machine applied.
+func TestTheGenerationOnTheWire(t *testing.T) {
+	raw := []byte(`{"node":"anchor","refused":"older generation","declared":"d12","epoch":57,"sequence":12,` +
+		`"report_sequence":8,"reads_generation":true,"older_generation":{"generation":38,"applied":40}}`)
+	var r Report
+	if err := json.Unmarshal(raw, &r); err != nil {
+		t.Fatal(err)
+	}
+	if !r.ReadsGeneration || r.OlderGeneration == nil || *r.OlderGeneration != (GenerationRefusal{38, 40}) ||
+		r.Sequence != 12 {
+		t.Fatalf("a node-engine's generation refusal reads as %+v", r)
+	}
+	// Not a refusal by the lease's epoch: S13 counts those, and this one is raised naming its sender.
+	if r.StaleRefusalOf() {
+		t.Errorf("a generation refusal reads as a stale writer's")
+	}
+	var older Report
+	if err := json.Unmarshal([]byte(`{"node":"anchor","applied":["a"],"report_sequence":3}`), &older); err != nil {
+		t.Fatal(err)
+	}
+	if older.ReadsGeneration || older.OlderGeneration != nil {
+		t.Fatalf("a node-engine that never said it reads a generation reads as one that does: %+v", older)
+	}
+}
diff --git a/internal/link/protocol.go b/internal/link/protocol.go
index b64a9a72..63349ece 100644
--- a/internal/link/protocol.go
+++ b/internal/link/protocol.go
@@ -197,6 +197,15 @@ type Report struct {
 	// RefusedOlder is how many declarations the node-engine has refused as older, ever, on every report:
 	// a refusal whose own report was lost is still counted from the next.
 	RefusedOlder int64 `json:"refused_older,omitempty"`
+	// ReadsGeneration says the node-engine reads a declaration's assignment generation and its put-back
+	// mark (novox/hq issue 234), on every report it makes: the mesh sends them only to a machine that said
+	// so, because an older node-engine refuses a key it does not know, whole. Mirrors mesh-host
+	// internal/link/messages.go.
+	ReadsGeneration bool `json:"reads_generation,omitempty"`
+	// OlderGeneration is set on a report refusing a declaration composed from an older assignment
+	// generation than the machine applied (novox/hq issue 234). The refused declaration is the report's
+	// own Declared and Order, and its sender is read from the record of sends by that sequence.
+	OlderGeneration *GenerationRefusal `json:"older_generation,omitempty"`
 
 	// Held is what an adopted node found and is keeping as it was until its module is taken
 	// (novox/hq ADR 0100). Without it an adopted node reads as converged.
@@ -605,3 +614,10 @@ type HealthSaid struct {
 	Node   string `json:"node"`
 	Health Health `json:"health"`
 }
+
+// GenerationRefusal is a declaration refused for the assignment generation it was composed from: that
+// generation, and the highest the machine applied (novox/hq issue 234; mesh-host's GenerationRefusal).
+type GenerationRefusal struct {
+	Generation int64 `json:"generation"`
+	Applied    int64 `json:"applied"`
+}

From 5dd0e3c056418e6aef6202d8b3e65758f89beadb Mon Sep 17 00:00:00 2001
From: jochen <jschoubben@gmail.com>
Date: Sun, 11 Oct 2026 11:55:27 +0200
Subject: [PATCH 4/4] Raise S20 for every generation refusal, ask for a push
 when the counter was behind, and write a send's generation with its digest
 (hq issue 234 review)

A refusal of a send the mesh never recorded went only to stderr; it is now kept
with its sender said to be unknown, and raised. A counter behind the machine (a
store put back) is raised and the condition names push, since the receive loop
must not push. The node's digest and generation are one transaction, and a send
record that fails is said loudly without failing the send. The trigger ignores
an update that changes nothing, and the put-back mark is dropped: a put-back is
composed afresh with the current generation.
---
 cmd/mesh-controller/facts.go                  |   2 +-
 cmd/mesh-controller/gate.go                   |   5 +-
 cmd/mesh-controller/generation.go             | 119 +++++++-----
 cmd/mesh-controller/generation_test.go        |  83 ++++++--
 cmd/mesh-controller/push.go                   |  38 ++--
 cmd/mesh-controller/release.go                |   3 -
 cmd/mesh-controller/sendable.go               |   9 -
 ...ation-says-the-generation-it-came-from.sql |  32 ++--
 internal/inventory/sends.go                   | 181 +++++++++++++-----
 internal/inventory/sends_test.go              |  97 ++++++++--
 10 files changed, 394 insertions(+), 175 deletions(-)

diff --git a/cmd/mesh-controller/facts.go b/cmd/mesh-controller/facts.go
index c1b6c891..50b891cf 100644
--- a/cmd/mesh-controller/facts.go
+++ b/cmd/mesh-controller/facts.go
@@ -515,7 +515,7 @@ func composedAndValidated(ctx context.Context, open *stores, node string, gens m
 		return sendable{}, nil, err
 	}
 	// And the generation it was last sent, as the would-send is (novox/hq issue 234).
-	if declared.Generation, declared.PutBack, err = open.inventory.SentGeneration(ctx, record.ID); err != nil {
+	if declared.Generation, err = open.inventory.SentGeneration(ctx, record.ID); err != nil {
 		return sendable{}, nil, err
 	}
 	body, err := declared.Body()
diff --git a/cmd/mesh-controller/gate.go b/cmd/mesh-controller/gate.go
index d7a71972..36eefc4d 100644
--- a/cmd/mesh-controller/gate.go
+++ b/cmd/mesh-controller/gate.go
@@ -994,8 +994,7 @@ func gateFailed(ctx context.Context, open *stores, p *inventory.Plan, module str
 		}
 		return
 	}
-	sent, err := sendRollout(withScope(ctx, sendScope{modules: map[string]bool{module: true}, putBack: true}), open,
-		g.Machines)
+	sent, err := sendRollout(withScope(ctx, sendScope{modules: map[string]bool{module: true}}), open, g.Machines)
 	if err != nil {
 		notBack(fmt.Sprintf("its registered build is back at %s, and sending it to %s was refused: %v — `push %s` "+
 			"sends it", short(previous.Commit), strings.Join(g.Machines, ", "), err, g.Machines[0]))
@@ -1088,7 +1087,7 @@ func sendRollbacks(ctx context.Context, open *stores, p *inventory.Plan, b *roll
 	}
 	inv := open.inventory
 	sort.Strings(b.machines)
-	sent, err := sendRollout(withScope(ctx, sendScope{modules: b.modules, putBack: true}), open, b.machines)
+	sent, err := sendRollout(withScope(ctx, sendScope{modules: b.modules}), open, b.machines)
 	var back []string
 	for _, r := range b.pending {
 		if err != nil {
diff --git a/cmd/mesh-controller/generation.go b/cmd/mesh-controller/generation.go
index f42d3fff..15f79cbb 100644
--- a/cmd/mesh-controller/generation.go
+++ b/cmd/mesh-controller/generation.go
@@ -33,15 +33,20 @@ const kindOlderGeneration = "older-generation"
 // generationRefusalsSaid is how long a refused send is said after its refusal: an hour, as an advisory is.
 const generationRefusalsSaid = advisoryQuiet
 
-// stamp gives a composed declaration the order allotted to it before it was composed: its sequence, the
-// epoch and generation when the machine reads them, and the put-back mark beside a generation — and keeps
-// the generation and acting epoch for the record of the send whether or not the machine is sent them.
+// stamp gives a composed declaration the order allotted to it before it was composed: its sequence, and
+// the epoch and generation when the machine reads them — and keeps the generation and acting epoch for the
+// record of the send whether or not the machine is sent them.
+//
+// **No put-back mark is sent.** A gate puts a machine back by composing it again (sendRollout), so its
+// declaration is allotted here like any other and carries the generation as it stands — never older than
+// what the machine applied. The node-engine reads a `put_back` key (mesh-host#82); this controller never
+// needs to send one.
 func (o order) stamp(d *sendable) {
 	d.Sequence, d.Epoch = o.sequence, o.epoch
-	d.composedFrom, d.actingEpoch, d.putBackSend = o.generation, o.acting, o.putBack
-	d.Generation, d.PutBack = 0, false
+	d.composedFrom, d.actingEpoch = o.generation, o.acting
+	d.Generation = 0
 	if o.readsGeneration && o.generation > 0 {
-		d.Generation, d.PutBack = o.generation, o.putBack
+		d.Generation = o.generation
 	}
 }
 
@@ -50,18 +55,17 @@ type sentRecord struct {
 	sequence   int64
 	epoch      uint64
 	generation int64
-	putBack    bool
-	// told is the generation and put-back mark on the wire, which the would-send is stamped with.
+	// toldGeneration is the generation on the wire, which the would-send is stamped with: zero for a machine
+	// whose node-engine has not said it reads one.
 	toldGeneration int64
-	toldPutBack    bool
 	sender         string
 	modules        []string
 }
 
 // sentRecordOf is a composed send's record: its sender is the caller this process acts for.
 func sentRecordOf(ctx context.Context, d sendable) sentRecord {
-	return sentRecord{sequence: d.Sequence, epoch: d.actingEpoch, generation: d.composedFrom, putBack: d.putBackSend,
-		toldGeneration: d.Generation, toldPutBack: d.PutBack, sender: senderOf(callerOf(ctx)), modules: d.modules}
+	return sentRecord{sequence: d.Sequence, epoch: d.actingEpoch, generation: d.composedFrom,
+		toldGeneration: d.Generation, sender: senderOf(callerOf(ctx)), modules: d.modules}
 }
 
 // callerOf is who asked for what this process does: the seat call's caller when ctx belongs to one, the
@@ -92,13 +96,19 @@ func namedModules(plan catalogue.Resolution, leftOut map[string]string) []string
 	return out
 }
 
-// heardGenerationRefusal keeps a machine's refusal of a send for its generation on the send it refused,
-// so S20 names its sender, and says it (novox/hq issue 234).
+// heardGenerationRefusal keeps a machine's refusal of a send for its generation, so S20 names its sender
+// and says it (novox/hq issue 234): on the send it refused or — when the mesh has no record of sending that
+// sequence — as a refusal of its own, naming the sender as unknown. Either way S20 is raised: a refusal the
+// mesh cannot attribute is the louder fact, not a quieter one.
 //
 // **And raises the mesh's counter past what the machine applied, when the refused send was composed from
-// the counter as it stands**: then the sender's view was not stale — the counter is behind the machine,
-// which is a store put back from a backup — and every send after would be refused for ever. A stale
-// sender's generation is below the counter, and the counter is left alone for it.
+// the counter as it stands** (counterBehind): then the sender's view was not stale — the counter is behind
+// the machine, which is a store put back from a backup — and every send after would be refused for ever. A
+// stale sender's generation is below the counter, and the counter is left alone for it.
+//
+// Nothing is sent from here. This runs in the controller's receive loop, and a push from it would hold that
+// loop, and the machine's hold, for as long as the push takes — the deaf controller of issues 184 and 185.
+// S20 names `push <node>` for that case instead.
 func heardGenerationRefusal(ctx context.Context, inv *inventory.Inventory, report link.Report) {
 	r := report.OlderGeneration
 	if r == nil || inv == nil || report.Node == "" {
@@ -106,35 +116,44 @@ func heardGenerationRefusal(ctx context.Context, inv *inventory.Inventory, repor
 	}
 	node, err := inv.NodeByName(ctx, report.Node)
 	if err != nil {
-		fmt.Fprintf(os.Stderr, "mesh-controller: %s refused a send for its generation, and the machine cannot be read: %v\n",
-			report.Node, err)
+		fmt.Fprintf(os.Stderr, "mesh-controller: %s refused a send for its generation, and the machine cannot be "+
+			"read, so it is not raised: %v\n", report.Node, err)
 		return
 	}
-	send, found, err := inv.RefusedSend(ctx, node.ID, report.Sequence, r.Applied)
-	switch {
-	case err != nil:
-		fmt.Fprintf(os.Stderr, "mesh-controller: %s refused send %d for its generation, and the refusal could not be "+
-			"kept: %v\n", report.Node, report.Sequence, err)
-	case !found:
-		fmt.Fprintf(os.Stderr, "mesh-controller: %s refused send %d (generation %d; it applied %d), which the mesh "+
-			"has no record of sending\n", report.Node, report.Sequence, r.Generation, r.Applied)
-	default:
-		fmt.Fprintf(os.Stderr, "mesh-controller: %s refused send %d from %s: composed from assignment generation %d, "+
-			"and it applied %d\n", report.Node, report.Sequence, send.Sender, r.Generation, r.Applied)
+	var raised int64
+	if now, err := inv.AssignmentGeneration(ctx); err != nil {
+		fmt.Fprintf(os.Stderr, "mesh-controller: %s refused a send for its generation, and the mesh's own cannot be "+
+			"read: %v\n", report.Node, err)
+	} else if counterBehind(*r, now) {
+		if raised, err = inv.RaiseAssignmentGeneration(ctx, r.Applied); err != nil {
+			fmt.Fprintf(os.Stderr, "mesh-controller: the assignment generation (%d) is behind what %s applied (%d), "+
+				"and could not be raised: %v\n", now, report.Node, r.Applied, err)
+			raised = 0
+		} else {
+			fmt.Fprintf(os.Stderr, "mesh-controller: the assignment generation was %d, behind what %s applied (%d) — "+
+				"a store put back from a backup — and is raised to %d; `push %s` sends it what the mesh holds now\n",
+				now, report.Node, r.Applied, raised, report.Node)
+		}
 	}
-	now, err := inv.AssignmentGeneration(ctx)
-	if err != nil || r.Generation < now || r.Applied < now {
-		return
+	send, found, err := inv.RefusedSend(ctx, node.ID, report.Sequence, r.Applied, raised)
+	if err == nil && !found {
+		send, err = inv.RecordUnrecordedRefusal(ctx, inventory.Send{Node: node.ID, Sequence: report.Sequence,
+			Epoch: report.Epoch, Generation: r.Generation, Digest: report.Declared, RefusedApplied: r.Applied,
+			CounterRaisedTo: raised})
 	}
-	raised, err := inv.RaiseAssignmentGeneration(ctx, r.Applied)
 	if err != nil {
-		fmt.Fprintf(os.Stderr, "mesh-controller: the assignment generation (%d) is behind what %s applied (%d), and "+
-			"could not be raised: %v\n", now, report.Node, r.Applied, err)
+		fmt.Fprintf(os.Stderr, "mesh-controller: %s refused send %d for its generation, and the refusal could not be "+
+			"kept, so it is not raised: %v\n", report.Node, report.Sequence, err)
 		return
 	}
-	fmt.Fprintf(os.Stderr, "mesh-controller: the assignment generation was %d, behind what %s applied (%d) — a store "+
-		"put back from a backup — and is raised to %d, so the next send is not refused\n", now, report.Node, r.Applied,
-		raised)
+	fmt.Fprintf(os.Stderr, "mesh-controller: %s refused send %d from %s: composed from assignment generation %d, "+
+		"and it applied %d\n", report.Node, report.Sequence, send.Sender, r.Generation, r.Applied)
+}
+
+// counterBehind says a refusal shows the mesh's counter behind the machine rather than a stale sender: the
+// refused send carried the counter as it stands now, and the machine applied more than that.
+func counterBehind(r link.GenerationRefusal, now int64) bool {
+	return r.Generation >= now && r.Applied > r.Generation
 }
 
 // watchGenerationRefusals is S20: every send a machine refused within the hour for the generation it was
@@ -147,7 +166,7 @@ func watchGenerationRefusals(f *signalFacts) []conditions.Observation {
 			continue
 		}
 		seen[s.NodeName] = true
-		out = append(out, conditions.Observation{Scope: conditions.ScopeMachine, ID: s.NodeName, Kind: kindOlderGeneration,
+		o := conditions.Observation{Scope: conditions.ScopeMachine, ID: s.NodeName, Kind: kindOlderGeneration,
 			Machine: s.NodeName, Severity: conditions.Warning,
 			Summary: fmt.Sprintf("%s refused sequence %d from %s: it was composed from assignment generation %d, and "+
 				"%s applied generation %d — a sender composing from a view of the assignments the mesh has moved "+
@@ -157,7 +176,20 @@ func watchGenerationRefusals(f *signalFacts) []conditions.Observation {
 			Headline: fmt.Sprintf("%s refused an out-of-date update", s.NodeName),
 			Explanation: fmt.Sprintf("Something sent %s an update made from an older list of what runs there. %s "+
 				"refused it, so nothing was removed. Nothing for you to do unless it repeats.", s.NodeName, s.NodeName),
-			Resolved: fmt.Sprintf("%s has had no out-of-date update for an hour", s.NodeName)})
+			Resolved: fmt.Sprintf("%s has had no out-of-date update for an hour", s.NodeName)}
+		if s.CounterRaisedTo > 0 {
+			// Not a stale sender: the mesh's counter was behind the machine (a store put back from a backup) and
+			// was raised; nothing has sent the machine its declaration since, so a person is asked to.
+			o.Summary = fmt.Sprintf("%s refused sequence %d from %s: it was composed from assignment generation %d, "+
+				"the mesh's own, and %s applied generation %d — the mesh's counter was behind the machine (a store "+
+				"put back from a backup?) and is raised to %d; `push %s` sends it what the mesh holds now",
+				s.NodeName, s.Sequence, s.Sender, s.Generation, s.NodeName, s.RefusedApplied, s.CounterRaisedTo,
+				s.NodeName)
+			o.Explanation = fmt.Sprintf("Needs you: push %s. The mesh's record was older than %s, so %s refused its "+
+				"update and kept what it had. The record is repaired; a push sends the update again.",
+				s.NodeName, s.NodeName, s.NodeName)
+		}
+		out = append(out, o)
 	}
 	return out
 }
@@ -181,12 +213,7 @@ func writeLastSend(ctx context.Context, w io.Writer, inv *inventory.Inventory, n
 	if s.Generation > 0 {
 		generation = fmt.Sprintf("assignment generation %d", s.Generation)
 	}
-	kind := "sent"
-	if s.PutBack {
-		kind = "put back"
-	}
-	fmt.Fprintf(w, "%s was last %s sequence %d at %s by %s, composed from %s, naming %s\n", node, kind,
-		s.Sequence, s.SentAt.Local().Format("2006-01-02 15:04:05"), s.Sender, generation, modulesWords(s.Modules))
+	fmt.Fprintf(w, "%s was last sent sequence %d at %s by %s, composed from %s, naming %s\n", node, s.Sequence, s.SentAt.Local().Format("2006-01-02 15:04:05"), s.Sender, generation, modulesWords(s.Modules))
 	if s.RefusedAt != nil {
 		fmt.Fprintf(w, "  and refused it at %s: it had applied generation %d\n",
 			s.RefusedAt.Local().Format("2006-01-02 15:04:05"), s.RefusedApplied)
diff --git a/cmd/mesh-controller/generation_test.go b/cmd/mesh-controller/generation_test.go
index f794760c..a2372bcc 100644
--- a/cmd/mesh-controller/generation_test.go
+++ b/cmd/mesh-controller/generation_test.go
@@ -7,6 +7,7 @@ import (
 	"time"
 
 	"github.com/novox/mesh-controller/internal/inventory"
+	"github.com/novox/mesh-controller/internal/link"
 )
 
 // The assignment generation a declaration was composed from (novox/hq issue 234).
@@ -25,45 +26,35 @@ func bodyKeys(t *testing.T, s sendable) map[string]any {
 }
 
 // **The generation goes on the wire only to a machine whose node-engine said it reads one**: an older
-// node-engine decodes strictly and refuses an unknown key, whole. And the put-back mark only with it.
+// node-engine decodes strictly and refuses an unknown key, whole. No put-back mark is ever sent: a gate
+// composes its put-back afresh, with the generation as it stands.
 func TestTheGenerationIsSentOnlyToAMachineThatReadsOne(t *testing.T) {
 	resources := []map[string]any{{"id": "a", "type": "file", "path": "/etc/a", "content": "x\n"}}
-	reads := order{sequence: 12, epoch: 57, generation: 40, readsGeneration: true, acting: 57, putBack: true}
+	reads := order{sequence: 12, epoch: 57, generation: 40, readsGeneration: true, acting: 57}
 	var told sendable
 	told.Resources = resources
 	reads.stamp(&told)
 	keys := bodyKeys(t, told)
-	if keys["generation"] != float64(40) || keys["put_back"] != true || keys["sequence"] != float64(12) {
+	if keys["generation"] != float64(40) || keys["sequence"] != float64(12) {
 		t.Fatalf("a machine that reads a generation was sent %v", keys)
 	}
+	if _, there := keys["put_back"]; there {
+		t.Fatalf("a put-back mark was sent: %v", keys)
+	}
 	if told.composedFrom != 40 || told.actingEpoch != 57 {
 		t.Errorf("the send does not keep what it was composed from for its record: %+v", told)
 	}
 
-	older := order{sequence: 12, epoch: 57, generation: 40, readsGeneration: false, acting: 57, putBack: true}
+	older := order{sequence: 12, epoch: 57, generation: 40, readsGeneration: false, acting: 57}
 	var untold sendable
 	untold.Resources = resources
 	older.stamp(&untold)
-	keys = bodyKeys(t, untold)
-	if _, there := keys["generation"]; there {
-		t.Fatalf("a machine whose node-engine never said it reads a generation was sent one: %v", keys)
-	}
-	if _, there := keys["put_back"]; there {
-		t.Fatalf("a machine whose node-engine never said it reads a generation was sent a put-back mark: %v", keys)
+	if _, there := bodyKeys(t, untold)["generation"]; there {
+		t.Fatal("a machine whose node-engine never said it reads a generation was sent one")
 	}
 	if untold.composedFrom != 40 {
 		t.Errorf("the generation it was composed from is recorded whether or not it was sent: %+v", untold)
 	}
-
-	// An ordinary send carries no put-back mark at all: the body is what it was apart from the generation.
-	var ordinary sendable
-	ordinary.Resources = resources
-	ordinaryOrder := reads
-	ordinaryOrder.putBack = false
-	ordinaryOrder.stamp(&ordinary)
-	if _, there := bodyKeys(t, ordinary)["put_back"]; there {
-		t.Fatal("an ordinary send says it is a put-back")
-	}
 }
 
 // **The sender is named**: the caller of the seat call when there is one, else the shell's account, and the
@@ -79,7 +70,7 @@ func TestASendNamesItsSender(t *testing.T) {
 func refusedSend(at time.Time) inventory.Send {
 	return inventory.Send{NodeName: "anchor", Sequence: 12, Epoch: 57, Generation: 38, RefusedApplied: 40,
 		Sender:  "a one-shot push by jochen at a shell on anchor (pid 4242 on anchor, build 2026.10.11)",
-		Modules: []string{"docker"}, SentAt: at.Add(-time.Second), RefusedAt: &at}
+		Modules: []string{"docker"}, SentAt: at.Add(-time.Second), RefusedAt: &at, Recorded: true}
 }
 
 // **A refused send is raised naming its sender** (novox/hq issue 234): who sent it, from which generation,
@@ -105,3 +96,53 @@ func TestARefusedSendIsRaisedNamingItsSender(t *testing.T) {
 		t.Errorf("the condition is not worded for the operator: %+v", o)
 	}
 }
+
+// **A refusal of a send the mesh has no record of is raised too, its sender said to be unknown** — never
+// only a line on stderr.
+func TestARefusalOfAnUnrecordedSendIsRaisedSayingTheSenderIsUnknown(t *testing.T) {
+	now := time.Date(2026, 10, 11, 12, 0, 0, 0, time.UTC)
+	f := calm(now)
+	s := refusedSend(now.Add(-time.Minute))
+	s.Recorded, s.Sender, s.Modules = false, "a sender the mesh has no record of (no send of this sequence was recorded)", nil
+	f.refusedSends = []inventory.Send{s}
+	got := watchGenerationRefusals(f)
+	if len(got) != 1 || !strings.Contains(got[0].Summary, "no record of") {
+		t.Fatalf("an unattributed refusal was not raised as one: %+v", got)
+	}
+}
+
+// **When the refusal showed the mesh's counter behind the machine, the condition asks for a push** — it was
+// raised, and nothing has sent the machine its declaration since — and does not say there is nothing to do.
+func TestACounterBehindTheMachineAsksForAPush(t *testing.T) {
+	now := time.Date(2026, 10, 11, 12, 0, 0, 0, time.UTC)
+	f := calm(now)
+	s := refusedSend(now.Add(-time.Minute))
+	s.Generation, s.RefusedApplied, s.CounterRaisedTo = 12, 40, 41
+	f.refusedSends = []inventory.Send{s}
+	got := watchGenerationRefusals(f)
+	if len(got) != 1 {
+		t.Fatalf("%+v", got)
+	}
+	if !strings.Contains(got[0].Summary, "`push anchor`") || !strings.Contains(got[0].Explanation, "push anchor") ||
+		strings.Contains(got[0].Explanation, "Nothing for you to do") {
+		t.Errorf("a counter behind the machine does not ask for a push: %s / %s", got[0].Summary, got[0].Explanation)
+	}
+}
+
+// **Only a refusal of the counter as it stands is the counter behind**: a stale sender's generation is below
+// it, and the counter is left alone for that.
+func TestOnlyARefusalOfTheCounterAsItStandsRaisesIt(t *testing.T) {
+	for _, c := range []struct {
+		refused, applied, now int64
+		behind                bool
+	}{
+		{refused: 12, applied: 40, now: 12, behind: true},  // the store was put back: the mesh says 12, the machine had 40
+		{refused: 38, applied: 40, now: 41, behind: false}, // a stale sender: the counter is already past
+		{refused: 38, applied: 40, now: 40, behind: false}, // a stale sender: the counter is where the machine is
+	} {
+		r := link.GenerationRefusal{Generation: c.refused, Applied: c.applied}
+		if got := counterBehind(r, c.now); got != c.behind {
+			t.Errorf("refused %d, applied %d, counter %d: behind %v, want %v", c.refused, c.applied, c.now, got, c.behind)
+		}
+	}
+}
diff --git a/cmd/mesh-controller/push.go b/cmd/mesh-controller/push.go
index be33434b..9f3c1434 100644
--- a/cmd/mesh-controller/push.go
+++ b/cmd/mesh-controller/push.go
@@ -359,14 +359,12 @@ func declare(ctx context.Context, args []string) error {
 		Epoch      uint64 `json:"epoch"`
 		Sequence   int64  `json:"sequence"`
 		Generation int64  `json:"generation"`
-		PutBack    bool   `json:"put_back"`
 	}
 	_ = json.Unmarshal(raw, &carried)
 	// And recorded as every send is (novox/hq issue 234): by hand, from what it carried; the modules it
 	// named are not known, since the mesh did not compose it.
 	if _, err := recordSent(ctx, inv, node, raw, nil, carried.Epoch, sentRecord{sequence: carried.Sequence,
-		epoch: carried.Epoch, generation: carried.Generation, putBack: carried.PutBack,
-		toldGeneration: carried.Generation, toldPutBack: carried.PutBack,
+		epoch: carried.Epoch, generation: carried.Generation, toldGeneration: carried.Generation,
 		sender: senderOf(callerOf(ctx)) + ", a declaration sent by hand"}); err != nil {
 		return err
 	}
@@ -1402,9 +1400,9 @@ func wouldSendFrom(ctx context.Context, open *stores,
 		if declared.Epoch, err = open.inventory.SentEpoch(ctx, n.ID); err != nil {
 			return nil, err
 		}
-		// And the generation and put-back mark it was last sent, for the same reason (novox/hq issue 234):
-		// an assignment elsewhere in the mesh is not a change of this machine.
-		if declared.Generation, declared.PutBack, err = open.inventory.SentGeneration(ctx, n.ID); err != nil {
+		// And the generation it was last sent, for the same reason (novox/hq issue 234): an assignment
+		// elsewhere in the mesh is not a change of this machine.
+		if declared.Generation, err = open.inventory.SentGeneration(ctx, n.ID); err != nil {
 			return nil, err
 		}
 		body, err := declared.Body()
@@ -1551,8 +1549,6 @@ type order struct {
 	generation      int64
 	readsGeneration bool
 	acting          uint64
-	// putBack is a gate's put-back (sendScope.putBack), read from the send's context.
-	putBack bool
 }
 
 // allot takes the next sequence for a machine — the number its next declaration carries — under the
@@ -1593,7 +1589,7 @@ func allot(ctx context.Context, inv *inventory.Inventory, node string) (order, e
 		return order{}, err
 	}
 	return order{sequence: seq, epoch: epoch, generation: generation, readsGeneration: readsGeneration,
-		acting: acting, putBack: scopeOf(ctx).putBack}, nil
+		acting: acting}, nil
 }
 
 // recordSent writes down what a machine was just sent, and returns the digest.
@@ -1616,17 +1612,23 @@ func recordSent(ctx context.Context, inv *inventory.Inventory, node string, body
 		return "", err
 	}
 	digest := digestOf(body)
-	if err := inv.RecordSentUnder(kept, record.ID, digest, builds, epoch); err != nil {
+	// The digest and the generation it carried are written in one transaction (novox/hq issue 234), so the
+	// would-send is never stamped with a generation the machine was not sent; and the send itself, who sent
+	// it and from which generation, beside them. A record of the send that cannot be written does not make a
+	// send that is away look failed: it is said, loudly, and the machine's own record stands.
+	err = inv.RecordSentWith(kept, record.ID, digest, builds, epoch, sent.toldGeneration, inventory.Send{
+		Sequence: sent.sequence, Epoch: int64(sent.epoch), Sender: sent.sender, Generation: sent.generation,
+		Digest: digest, Modules: sent.modules})
+	var unrecorded *inventory.SendNotRecordedError
+	switch {
+	case errors.As(err, &unrecorded):
+		fmt.Fprintf(os.Stderr, "mesh-controller: SEND NOT RECORDED: %s was sent declaration %s (sequence %d), and who "+
+			"sent it and from which generation could not be written down, so a refusal of it will name no sender "+
+			"(novox/hq issue 234): %v\n", node, short(digest), sent.sequence, unrecorded.Err)
+		fmt.Printf("%s: sent, and the record of who sent it could NOT be written: %v\n", node, unrecorded.Err)
+	case err != nil:
 		return "", err
 	}
-	// And the send itself, who sent it and from which generation (novox/hq issue 234): what the machine
-	// was last told, by whom, is read back from here — and what the would-send is stamped with.
-	if err := inv.RecordSend(kept, inventory.Send{Node: record.ID, Sequence: sent.sequence,
-		Epoch: int64(sent.epoch), Sender: sent.sender, Generation: sent.generation, PutBack: sent.putBack,
-		ToldGeneration: sent.toldGeneration, ToldPutBack: sent.toldPutBack, Digest: digest,
-		Modules: sent.modules}); err != nil {
-		return "", fmt.Errorf("%s was sent its declaration, and the send could not be recorded: %w", node, err)
-	}
 	// And what it was, summarised, so the next push can be compared with it (novox/hq ADR 0217).
 	// Never a reason to fail a send that is already away: a summary that cannot be kept means the
 	// next comparison has nothing to hold against, which is how every machine starts.
diff --git a/cmd/mesh-controller/release.go b/cmd/mesh-controller/release.go
index 31c1ef87..56b702c8 100644
--- a/cmd/mesh-controller/release.go
+++ b/cmd/mesh-controller/release.go
@@ -50,9 +50,6 @@ type sendScope struct {
 	modules map[string]bool
 	// person is a person's act: it carries what it carries.
 	person bool
-	// putBack is a gate putting machines back after a failed send (novox/hq issue 234): its declarations
-	// say so, and a machine does not refuse them for the generation they carry.
-	putBack bool
 }
 
 type sendScopeKey struct{}
diff --git a/cmd/mesh-controller/sendable.go b/cmd/mesh-controller/sendable.go
index cbc89943..0c1e2116 100644
--- a/cmd/mesh-controller/sendable.go
+++ b/cmd/mesh-controller/sendable.go
@@ -33,17 +33,11 @@ type sendable struct {
 	// node-engine has not said it reads one is sent none, for the reason the epoch is not (an older
 	// node-engine refuses a key it does not know, whole).
 	Generation int64
-	// PutBack marks a gate's put-back (novox/hq issue 234): it carries the generation of what it puts
-	// back and is not refused for it. Sent only beside a generation.
-	PutBack bool
 	// composedFrom is the generation read before this declaration was composed, and actingEpoch the
 	// lease epoch its sender acted under — whether or not the machine is sent either — for the record of
 	// the send; never on the wire.
 	composedFrom int64
 	actingEpoch  uint64
-	// putBackSend is whether a gate sent it to put the machine back, for the record; PutBack is the mark
-	// on the wire, only beside a generation.
-	putBackSend bool
 	// modules are the modules this declaration names, for the record of the send; never on the wire.
 	modules []string
 	// Adoption is nil for a converged node, and then the body is byte for byte what it was before
@@ -115,9 +109,6 @@ func (s sendable) Body() ([]byte, error) {
 	}
 	if s.Generation > 0 {
 		envelope["generation"] = s.Generation
-		if s.PutBack {
-			envelope["put_back"] = true
-		}
 	}
 	// An empty declaration is deliberate here — the node owns nothing the mesh put there
 	// (novox/hq issue 127) — and the host refuses an empty body unless it is told the emptiness
diff --git a/internal/inventory/migrations/0094-a-declaration-says-the-generation-it-came-from.sql b/internal/inventory/migrations/0094-a-declaration-says-the-generation-it-came-from.sql
index 07a182d3..52dde45b 100644
--- a/internal/inventory/migrations/0094-a-declaration-says-the-generation-it-came-from.sql
+++ b/internal/inventory/migrations/0094-a-declaration-says-the-generation-it-came-from.sql
@@ -24,26 +24,33 @@ begin
 end
 $$;
 
--- Per row, so a statement that changes nothing (an assignment repeated, `on conflict do nothing`) raises
--- nothing; a statement that changes several raises once per row, which only ever moves it forward.
+-- Per row, so a statement that changes nothing raises nothing: an assignment repeated (`on conflict do
+-- nothing` inserts no row) and an update that leaves a row as it was (the WHEN below; a plain UPDATE fires a
+-- row trigger whether or not it changed anything). A statement that changes several rows raises once per
+-- row, which only ever moves it forward. Two triggers, because only an update has both OLD and NEW.
 create trigger assignment_generation_raised
-    after insert or update or delete on assignment
+    after insert or delete on assignment
     for each row execute function raise_assignment_generation();
+create trigger assignment_generation_raised_by_update
+    after update on assignment
+    for each row when (old is distinct from new) execute function raise_assignment_generation();
 
--- What a machine was last sent of it: the generation, and whether that send was a gate's put-back, so
+-- The generation a machine was last sent, written in the same transaction as the digest of that send, so
 -- what the mesh WOULD send is stamped the same way and reads as byte for byte what it DID send when
--- nothing else changed (as sent_epoch, migration 0068). Null and false for a send without.
+-- nothing else changed (as sent_epoch, migration 0068). Null for a send without one.
 alter table node add column sent_generation bigint;
-alter table node add column sent_put_back boolean not null default false;
 -- Whether the machine's node-engine said it reads a generation (its reports' `reads_generation`): until
 -- it has, it is sent none, because an older node-engine refuses a key it does not know, whole.
 alter table node add column reads_generation boolean not null default false;
 
 -- Every send: the machine, its sequence, who sent it — the lease epoch the sender acted under and the
--- caller, process and build — the generation it was composed from, whether it was a put-back, its
--- digest and the modules it named. Written after the declaration is away, as the node row's record is.
--- A refusal by the machine of a send for its generation is kept on the send it refused, so the
--- condition it raises names the sender from here. The newest 200 per machine are kept.
+-- caller, process and build — the generation it was composed from, its digest and the modules it named.
+-- Written after the declaration is away, with the node row's record of it. A refusal by the machine of a
+-- send for its generation is kept on the send it refused, so the condition it raises names the sender
+-- from here; a refusal of a sequence the mesh has no send for is kept as a row of its own, `recorded`
+-- false, whose sender is said to be unknown. `counter_raised_to` is the generation the mesh's counter was
+-- raised to when the refusal showed the counter behind the machine (a store put back from a backup). The
+-- newest 200 per machine are kept.
 create table declaration_send (
     id           bigserial   primary key,
     node         uuid        not null references node (id) on delete cascade,
@@ -51,13 +58,14 @@ create table declaration_send (
     epoch        bigint,
     sender       text        not null,
     generation   bigint,
-    put_back     boolean     not null default false,
     digest       text        not null,
     modules      text[]      not null default '{}',
     sent_at      timestamptz not null default now(),
     refused_at   timestamptz,
     -- refused_applied is the generation the machine said it had applied when it refused this send.
-    refused_applied bigint
+    refused_applied bigint,
+    counter_raised_to bigint,
+    recorded     boolean     not null default true
 );
 create index declaration_send_node on declaration_send (node, id desc);
 create index declaration_send_sequence on declaration_send (node, sequence);
diff --git a/internal/inventory/sends.go b/internal/inventory/sends.go
index 085a2ac9..8a6efa36 100644
--- a/internal/inventory/sends.go
+++ b/internal/inventory/sends.go
@@ -2,6 +2,7 @@ package inventory
 
 import (
 	"context"
+	"encoding/json"
 	"fmt"
 	"time"
 
@@ -47,20 +48,17 @@ func (i *Inventory) RaiseAssignmentGeneration(ctx context.Context, past int64) (
 	return g, nil
 }
 
-// SentGeneration is the generation a machine was last sent and whether that send was a put-back, by its
-// id; zero for one sent without. What the mesh WOULD send is stamped with these, so it reads as byte for
-// byte what it DID send when nothing else changed.
-func (i *Inventory) SentGeneration(ctx context.Context, id string) (int64, bool, error) {
+// SentGeneration is the generation a machine was last sent, by its id; zero for one sent without. What the
+// mesh WOULD send is stamped with it, so it reads as byte for byte what it DID send when nothing else changed.
+func (i *Inventory) SentGeneration(ctx context.Context, id string) (int64, error) {
 	var g *int64
-	var putBack bool
-	if err := i.store.Pool().QueryRow(ctx, `select sent_generation, sent_put_back from node where id = $1`, id).
-		Scan(&g, &putBack); err != nil {
-		return 0, false, fmt.Errorf("reading the generation %s was last sent: %w", id, err)
+	if err := i.store.Pool().QueryRow(ctx, `select sent_generation from node where id = $1`, id).Scan(&g); err != nil {
+		return 0, fmt.Errorf("reading the generation %s was last sent: %w", id, err)
 	}
 	if g == nil {
-		return 0, putBack, nil
+		return 0, nil
 	}
-	return *g, putBack, nil
+	return *g, nil
 }
 
 // ReadsGeneration says a machine's node-engine said it reads a generation in a declaration, by its id.
@@ -88,66 +86,122 @@ type Send struct {
 	Epoch int64
 	// Sender is who sent it, in words: the caller, and the process and build that composed it.
 	Sender string
-	// Generation is the assignment generation it was composed from, zero when not known; PutBack whether a
-	// gate sent it to put the machine back.
+	// Generation is the assignment generation it was composed from, zero when not known.
 	Generation int64
-	PutBack    bool
-	// ToldGeneration and ToldPutBack are what the machine was told of them on the wire: zero and false for a
-	// machine whose node-engine has not said it reads a generation. What the would-send is stamped with.
-	ToldGeneration int64
-	ToldPutBack    bool
-	Digest         string
+	Digest     string
 	// Modules are the modules it named.
 	Modules []string
 	SentAt  time.Time
 	// RefusedAt is when the machine refused it for its generation, nil when it did not; RefusedApplied the
-	// generation the machine said it had applied then.
-	RefusedAt      *time.Time
-	RefusedApplied int64
+	// generation the machine said it had applied then; CounterRaisedTo what the mesh's counter was raised to
+	// because the refusal showed it behind the machine, zero when it was not.
+	RefusedAt       *time.Time
+	RefusedApplied  int64
+	CounterRaisedTo int64
+	// Recorded is false for a refusal of a sequence the mesh has no send for: its sender is unknown.
+	Recorded bool
 }
 
-// RecordSend writes one send down, and what the machine was last sent of its generation, in one
-// transaction; the oldest beyond the newest 200 for the machine are let go.
-func (i *Inventory) RecordSend(ctx context.Context, s Send) error {
+// unknownSender is the sender of a refused sequence the mesh has no record of sending.
+const unknownSender = "a sender the mesh has no record of (no send of this sequence was recorded: sent by " +
+	"hand, before sends were recorded, or by a controller whose record was not written)"
+
+// SendNotRecordedError is a send whose machine's record was written — its digest and the generation it
+// carried — and whose record of who sent it was not. The send is away and the machine's record stands; the
+// caller says this loudly and does not take the send for failed.
+type SendNotRecordedError struct{ Err error }
+
+func (e *SendNotRecordedError) Error() string {
+	return "the record of the send was not written: " + e.Err.Error()
+}
+func (e *SendNotRecordedError) Unwrap() error { return e.Err }
+
+// RecordSentWith writes down what a machine was just sent — its digest, the builds it carried, the epoch and
+// the generation on the wire — and the send itself, who sent it and from which generation (novox/hq issue
+// 234), in one transaction. The digest and the generation are written together, so the would-send is never
+// stamped with a generation the machine was not sent. The send's own record is written under a savepoint: if
+// it cannot be, the machine's record is still committed and a *SendNotRecordedError says so. The oldest
+// sends beyond the newest 200 for the machine are let go.
+func (i *Inventory) RecordSentWith(ctx context.Context, node, digest string, builds map[string]string, epoch uint64,
+	generation int64, s Send) error {
+	var sentEpoch *int64
+	if epoch > 0 {
+		e := int64(epoch)
+		sentEpoch = &e
+	}
+	var carried *string
+	if builds != nil {
+		raw, err := json.Marshal(builds)
+		if err != nil {
+			return err
+		}
+		text := string(raw)
+		carried = &text
+	}
 	tx, err := i.store.Pool().Begin(ctx)
 	if err != nil {
 		return err
 	}
 	defer func() { _ = tx.Rollback(ctx) }()
-	if _, err := tx.Exec(ctx, `update node set sent_generation = $2, sent_put_back = $3 where id = $1`,
-		s.Node, nullIfZero(s.ToldGeneration), s.ToldPutBack); err != nil {
+	if _, err := tx.Exec(ctx,
+		`update node set sent = $2, sent_at = now(), sent_builds = $3::jsonb, sent_epoch = $4, sent_generation = $5
+		  where id = $1`, node, digest, carried, sentEpoch, nullIfZero(generation)); err != nil {
 		return err
 	}
+	recordErr := recordSend(ctx, tx, node, s)
+	if err := tx.Commit(ctx); err != nil {
+		return err
+	}
+	if recordErr != nil {
+		return &SendNotRecordedError{Err: recordErr}
+	}
+	return nil
+}
+
+// recordSend writes one send under a savepoint of tx, which it rolls back when the send cannot be written.
+func recordSend(ctx context.Context, tx pgx.Tx, node string, s Send) error {
+	sp, err := tx.Begin(ctx)
+	if err != nil {
+		return err
+	}
+	defer func() { _ = sp.Rollback(ctx) }()
 	modules := s.Modules
 	if modules == nil {
 		modules = []string{}
 	}
-	if _, err := tx.Exec(ctx,
-		`insert into declaration_send (node, sequence, epoch, sender, generation, put_back, digest, modules)
-		 values ($1, $2, $3, $4, $5, $6, $7, $8)`,
-		s.Node, nullIfZero(s.Sequence), nullIfZero(s.Epoch), s.Sender, nullIfZero(s.Generation), s.PutBack,
-		s.Digest, modules); err != nil {
+	if _, err := sp.Exec(ctx,
+		`insert into declaration_send (node, sequence, epoch, sender, generation, digest, modules)
+		 values ($1, $2, $3, $4, $5, $6, $7)`,
+		node, nullIfZero(s.Sequence), nullIfZero(s.Epoch), s.Sender, nullIfZero(s.Generation), s.Digest,
+		modules); err != nil {
 		return err
 	}
-	if _, err := tx.Exec(ctx,
+	if err := pruneSends(ctx, sp, node); err != nil {
+		return err
+	}
+	return sp.Commit(ctx)
+}
+
+// pruneSends lets go of a machine's sends beyond the newest 200.
+func pruneSends(ctx context.Context, q queries, node string) error {
+	_, err := q.Exec(ctx,
 		`delete from declaration_send where node = $1 and id not in
-		   (select id from declaration_send where node = $1 order by id desc limit $2)`, s.Node, sendsKept); err != nil {
-		return err
-	}
-	return tx.Commit(ctx)
+		   (select id from declaration_send where node = $1 order by id desc limit $2)`, node, sendsKept)
+	return err
 }
 
 // sendColumns are a send's columns as scanSends reads them.
 const sendColumns = `s.node, n.name, coalesce(s.sequence, 0), coalesce(s.epoch, 0), s.sender, coalesce(s.generation, 0),
-	s.put_back, s.digest, s.modules, s.sent_at, s.refused_at, coalesce(s.refused_applied, 0)`
+	s.digest, s.modules, s.sent_at, s.refused_at, coalesce(s.refused_applied, 0), coalesce(s.counter_raised_to, 0),
+	s.recorded`
 
 func scanSends(rows pgx.Rows) ([]Send, error) {
 	defer rows.Close()
 	var out []Send
 	for rows.Next() {
 		var s Send
-		if err := rows.Scan(&s.Node, &s.NodeName, &s.Sequence, &s.Epoch, &s.Sender, &s.Generation, &s.PutBack,
-			&s.Digest, &s.Modules, &s.SentAt, &s.RefusedAt, &s.RefusedApplied); err != nil {
+		if err := rows.Scan(&s.Node, &s.NodeName, &s.Sequence, &s.Epoch, &s.Sender, &s.Generation, &s.Digest,
+			&s.Modules, &s.SentAt, &s.RefusedAt, &s.RefusedApplied, &s.CounterRaisedTo, &s.Recorded); err != nil {
 			return nil, err
 		}
 		out = append(out, s)
@@ -155,11 +209,12 @@ func scanSends(rows pgx.Rows) ([]Send, error) {
 	return out, rows.Err()
 }
 
-// LastSend is the last declaration a machine was sent, by its name; false when none was recorded.
+// LastSend is the last declaration a machine was sent, by its name; false when none was recorded. A refusal
+// of a sequence the mesh has no send for is not a send, and is not it.
 func (i *Inventory) LastSend(ctx context.Context, name string) (Send, bool, error) {
 	rows, err := i.store.Pool().Query(ctx, `select `+sendColumns+`
 		  from declaration_send s join node n on n.id = s.node
-		 where n.name = $1 order by s.id desc limit 1`, name)
+		 where n.name = $1 and s.recorded order by s.id desc limit 1`, name)
 	if err != nil {
 		return Send{}, false, err
 	}
@@ -171,15 +226,17 @@ func (i *Inventory) LastSend(ctx context.Context, name string) (Send, bool, erro
 }
 
 // RefusedSend keeps a machine's refusal of the send of a sequence for the generation it came from, and
-// answers that send, sender and all; false when no send of that sequence was recorded — sent before the
-// record, or by a hand the mesh did not see. The newest of that sequence when there are several: a
-// declaration a person sent by hand may repeat one.
-func (i *Inventory) RefusedSend(ctx context.Context, node string, sequence, applied int64) (Send, bool, error) {
+// answers that send, sender and all; false when no send of that sequence was recorded (RecordUnrecordedRefusal
+// keeps that one). The newest of that sequence when there are several: a declaration a person sent by hand may
+// repeat one. raisedTo is what the mesh's counter was raised to for it, zero for none.
+func (i *Inventory) RefusedSend(ctx context.Context, node string, sequence, applied, raisedTo int64) (Send, bool, error) {
 	rows, err := i.store.Pool().Query(ctx, `with refused as (
-		update declaration_send set refused_at = now(), refused_applied = $3
-		 where id = (select id from declaration_send where node = $1 and sequence = $2 order by id desc limit 1)
+		update declaration_send set refused_at = now(), refused_applied = $3, counter_raised_to = $4
+		 where id = (select id from declaration_send where node = $1 and sequence = $2 and recorded
+		              order by id desc limit 1)
 		returning *)
-		select `+sendColumns+` from refused s join node n on n.id = s.node`, node, sequence, applied)
+		select `+sendColumns+` from refused s join node n on n.id = s.node`, node, sequence, applied,
+		nullIfZero(raisedTo))
 	if err != nil {
 		return Send{}, false, err
 	}
@@ -190,6 +247,34 @@ func (i *Inventory) RefusedSend(ctx context.Context, node string, sequence, appl
 	return sends[0], true, nil
 }
 
+// RecordUnrecordedRefusal keeps a machine's refusal of a sequence the mesh has no send for, as a row of its
+// own whose sender is unknown, and answers it: S20 raises it like any other, because a refusal nobody can
+// attribute is no quieter for that. s carries the machine, the sequence, epoch, generation and digest the
+// refused declaration carried, and the refusal's applied generation and counter raise.
+func (i *Inventory) RecordUnrecordedRefusal(ctx context.Context, s Send) (Send, error) {
+	rows, err := i.store.Pool().Query(ctx, `with refused as (
+		insert into declaration_send (node, sequence, epoch, sender, generation, digest, refused_at, refused_applied,
+		                              counter_raised_to, recorded)
+		values ($1, $2, $3, $4, $5, $6, now(), $7, $8, false) returning *)
+		select `+sendColumns+` from refused s join node n on n.id = s.node`,
+		s.Node, nullIfZero(s.Sequence), nullIfZero(s.Epoch), unknownSender, nullIfZero(s.Generation), s.Digest,
+		s.RefusedApplied, nullIfZero(s.CounterRaisedTo))
+	if err != nil {
+		return Send{}, err
+	}
+	sends, err := scanSends(rows)
+	if err != nil {
+		return Send{}, err
+	}
+	if len(sends) == 0 {
+		return Send{}, fmt.Errorf("the refusal of sequence %d was not kept", s.Sequence)
+	}
+	if err := pruneSends(ctx, i.store.Pool(), s.Node); err != nil {
+		return Send{}, err
+	}
+	return sends[0], nil
+}
+
 // RefusedSendsSince is every send refused for its generation since a moment, newest first.
 func (i *Inventory) RefusedSendsSince(ctx context.Context, since time.Time) ([]Send, error) {
 	rows, err := i.store.Pool().Query(ctx, `select `+sendColumns+`
diff --git a/internal/inventory/sends_test.go b/internal/inventory/sends_test.go
index 9f5dfe6b..96c98d15 100644
--- a/internal/inventory/sends_test.go
+++ b/internal/inventory/sends_test.go
@@ -1,6 +1,7 @@
 package inventory
 
 import (
+	"errors"
 	"slices"
 	"testing"
 	"time"
@@ -75,8 +76,8 @@ func TestTheGenerationIsRaisedPastWhatAMachineApplied(t *testing.T) {
 }
 
 // **Every send is recorded: its sequence, its sender, the generation it came from and the modules it
-// named** — and the machine's last send is what `plan` reads, the would-send is stamped with its
-// generation and put-back mark, and a refusal is kept on the send it refused, naming its sender.
+// named** — and the machine's last send is what `plan` reads, the would-send is stamped with the generation
+// written with the digest, and a refusal is kept on the send it refused, naming its sender.
 func TestASendIsRecordedWithItsSenderGenerationAndModules(t *testing.T) {
 	inv, node := aNodeWithModules(t)
 	ctx := t.Context()
@@ -84,42 +85,110 @@ func TestASendIsRecordedWithItsSenderGenerationAndModules(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	first := Send{Node: record.ID, Sequence: 11, Epoch: 57, Sender: "the controller's daemon (pid 7 on anchor)",
+	first := Send{Sequence: 11, Epoch: 57, Sender: "the controller's daemon (pid 7 on anchor)",
 		Generation: 40, Digest: "d11", Modules: []string{"docker", "pacman", "sudo"}}
-	if err := inv.RecordSend(ctx, first); err != nil {
+	if err := inv.RecordSentWith(ctx, record.ID, "d11", nil, 57, 40, first); err != nil {
 		t.Fatal(err)
 	}
-	stale := Send{Node: record.ID, Sequence: 12, Epoch: 57, Sender: "a one-shot push by jochen at a shell on anchor",
-		Generation: 38, ToldGeneration: 38, Digest: "d12", Modules: []string{"docker"}}
-	if err := inv.RecordSend(ctx, stale); err != nil {
+	stale := Send{Sequence: 12, Epoch: 57, Sender: "a one-shot push by jochen at a shell on anchor",
+		Generation: 38, Digest: "d12", Modules: []string{"docker"}}
+	if err := inv.RecordSentWith(ctx, record.ID, "d12", nil, 57, 38, stale); err != nil {
 		t.Fatal(err)
 	}
 	last, found, err := inv.LastSend(ctx, node)
 	if err != nil || !found {
 		t.Fatalf("the last send is not kept: %v", err)
 	}
-	if last.Sequence != 12 || last.Sender != stale.Sender || last.Generation != 38 ||
+	if last.Sequence != 12 || last.Sender != stale.Sender || last.Generation != 38 || !last.Recorded ||
 		!slices.Equal(last.Modules, []string{"docker"}) || last.SentAt.IsZero() {
 		t.Fatalf("the last send reads %+v", last)
 	}
-	generation, putBack, err := inv.SentGeneration(ctx, record.ID)
-	if err != nil || generation != 38 || putBack {
-		t.Fatalf("what the machine was last sent of it reads %d, %v (%v)", generation, putBack, err)
+	if generation, err := inv.SentGeneration(ctx, record.ID); err != nil || generation != 38 {
+		t.Fatalf("what the machine was last sent of it reads %d (%v)", generation, err)
 	}
 
-	refused, found, err := inv.RefusedSend(ctx, record.ID, 12, 40)
-	if err != nil || !found || refused.Sender != stale.Sender || refused.RefusedApplied != 40 {
+	refused, found, err := inv.RefusedSend(ctx, record.ID, 12, 40, 0)
+	if err != nil || !found || refused.Sender != stale.Sender || refused.RefusedApplied != 40 ||
+		refused.CounterRaisedTo != 0 {
 		t.Fatalf("the refusal is not kept on the send it refused: %+v, %v, %v", refused, found, err)
 	}
 	since, err := inv.RefusedSendsSince(ctx, time.Now().Add(-time.Hour))
 	if err != nil || len(since) != 1 || since[0].NodeName != node || since[0].Sequence != 12 {
 		t.Fatalf("the refused sends within the hour read %+v (%v)", since, err)
 	}
-	if _, found, err := inv.RefusedSend(ctx, record.ID, 99, 40); err != nil || found {
+	if _, found, err := inv.RefusedSend(ctx, record.ID, 99, 40, 0); err != nil || found {
 		t.Errorf("a refusal of a send never recorded was found: %v, %v", found, err)
 	}
 }
 
+// **A refusal of a sequence the mesh has no send for is kept too, its sender unknown**, so S20 raises it;
+// it is not the machine's last send, and it says what the counter was raised to.
+func TestARefusalOfASendNeverRecordedIsKeptWithAnUnknownSender(t *testing.T) {
+	inv, node := aNodeWithModules(t)
+	ctx := t.Context()
+	record, err := inv.NodeByName(ctx, node)
+	if err != nil {
+		t.Fatal(err)
+	}
+	kept, err := inv.RecordUnrecordedRefusal(ctx, Send{Node: record.ID, Sequence: 99, Epoch: 57, Generation: 41,
+		Digest: "d99", RefusedApplied: 44, CounterRaisedTo: 45})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if kept.Recorded || kept.Sender != unknownSender || kept.RefusedAt == nil || kept.CounterRaisedTo != 45 ||
+		kept.NodeName != node {
+		t.Fatalf("the refusal reads %+v", kept)
+	}
+	since, err := inv.RefusedSendsSince(ctx, time.Now().Add(-time.Hour))
+	if err != nil || len(since) != 1 || since[0].Sequence != 99 {
+		t.Fatalf("the refused sends within the hour read %+v (%v)", since, err)
+	}
+	if _, found, err := inv.LastSend(ctx, node); err != nil || found {
+		t.Errorf("a refusal of a send never recorded reads as the machine's last send: %v, %v", found, err)
+	}
+}
+
+// **The machine's record and the send's are written together, and a send record that cannot be written
+// leaves the machine's record standing and says so**: the digest and generation are the machine's, and a
+// send that is away must not read as failed, nor the machine as behind.
+func TestASendRecordThatCannotBeWrittenLeavesTheMachinesRecord(t *testing.T) {
+	inv, node := aNodeWithModules(t)
+	ctx := t.Context()
+	record, err := inv.NodeByName(ctx, node)
+	if err != nil {
+		t.Fatal(err)
+	}
+	// A NUL byte is text PostgreSQL refuses: the send's own row cannot be written.
+	broken := Send{Sequence: 13, Sender: "a test", Generation: 42, Digest: "d\x0013"}
+	err = inv.RecordSentWith(ctx, record.ID, "d13", nil, 0, 42, broken)
+	var unrecorded *SendNotRecordedError
+	if !errors.As(err, &unrecorded) {
+		t.Fatalf("a send record that could not be written read as %v", err)
+	}
+	if generation, err := inv.SentGeneration(ctx, record.ID); err != nil || generation != 42 {
+		t.Fatalf("the machine's generation was not written with its digest: %d (%v)", generation, err)
+	}
+	if sent, err := inv.Outstanding(ctx, node); err != nil || sent != "d13" {
+		t.Fatalf("the machine's digest was not written: %q (%v)", sent, err)
+	}
+}
+
+// **An update that leaves an assignment as it was raises nothing** (the trigger's WHEN).
+func TestAnUpdateThatChangesNoAssignmentRaisesNothing(t *testing.T) {
+	inv, node := aNodeWithModules(t, "web")
+	ctx := t.Context()
+	if _, err := inv.Assign(ctx, node, "web"); err != nil {
+		t.Fatal(err)
+	}
+	before := generationNow(t, inv)
+	if _, err := inv.store.Pool().Exec(ctx, `update assignment set module = module`); err != nil {
+		t.Fatal(err)
+	}
+	if after := generationNow(t, inv); after != before {
+		t.Errorf("an update that changed nothing moved the generation from %d to %d", before, after)
+	}
+}
+
 // **A machine that reads a generation is recorded from its reports**, and one rolled back says so no longer.
 func TestWhetherAMachineReadsAGenerationIsItsLatestWord(t *testing.T) {
 	inv, node := aNodeWithModules(t)