Let failed join the seat optional, and let a seeded row carry both changes

failed was required, so the controller refused the systemd module running
today and the module serving it was refused by the controller running
today: neither could land first. It is now optional (Verb.Optional, #117).

Two things kept either change from reaching a mesh whose seat rows already
exist: re-seeding added a verb but never an argument to one, and the
console refuses an argument the row does not name, so the journal window
would stay unreachable; and the optional mark is never stored, so a verb
seeded into a row came back required. A row's verb now gains the arguments
the binary names, and the working set takes the optional mark from the
compiled seat, which also keeps mesh-delivery's checks optional once seeded.

cmd/mesh-controller/seat_dependencies_test.go

@@ -15,7 +15,7 @@ import (
 func serviceManagerHolder() catalogue.Manifest {
 	return catalogue.Manifest{Module: "systemd", Version: "1",
 		Claims: []catalogue.Claim{{Name: catalogue.ServiceManagerSeat, Scope: catalogue.ScopeNode,
-			Serves: []string{"units", "status", "start", "stop", "restart", "enable", "disable", "journal", "failed"}}},
+			Serves: []string{"units", "status", "start", "stop", "restart", "enable", "disable", "journal"}}},
 		Resources: []map[string]any{{"id": "systemd", "type": "package", "package": "systemd"}}}
 }
 

internal/catalogue/operators_machine_test.go

@@ -58,3 +58,53 @@ func TestTheServiceManagerSeatServesTheUnitVerbs(t *testing.T) {
 		t.Fatalf("the seat serves %v, not %v", got, want)
 	}
 }
+
+// **`failed` joins the seat optional** (the operator's direction 2026-10-07): the holder running today,
+// which does not serve it, still holds the seat; the holder that serves it is not refused; and a verb
+// the seat does not promise is still refused, and one it requires is still required.
+func TestFailedIsAnOptionalVerbOfTheServiceManager(t *testing.T) {
+	seat, _ := SeatNamed(ServiceManagerSeat)
+	holder := func(serves ...string) Manifest {
+		return Manifest{Module: "systemd", Version: "1", Claims: []Claim{{Name: ServiceManagerSeat, Scope: ScopeNode, Serves: serves}}}
+	}
+	eight := []string{"units", "status", "start", "stop", "restart", "enable", "disable", "journal"}
+	if err := CanHold(holder(eight...), seat); err != nil {
+		t.Fatalf("today's holder, without failed, is refused: %v", err)
+	}
+	if err := CanHold(holder(append(eight, "failed")...), seat); err != nil {
+		t.Fatalf("a holder serving failed is refused: %v", err)
+	}
+	if err := CanHold(holder(append(eight, "fail")...), seat); err == nil || !strings.Contains(err.Error(), "does not promise") {
+		t.Fatalf("a verb the seat does not promise was accepted: %v", err)
+	}
+	if err := CanHold(holder(eight[1:]...), seat); err == nil || !strings.Contains(err.Error(), "does not serve units") {
+		t.Fatalf("a holder missing a required verb was accepted: %v", err)
+	}
+	for _, v := range seat.Serves {
+		if v.Optional != (v.Name == "failed") {
+			t.Errorf("%s optional: %v", v.Name, v.Optional)
+		}
+	}
+}
+
+// The optional mark is not stored, so a seat set read back from the store's rows takes it from the
+// compiled seat: otherwise `failed`, seeded into the row, would come back required.
+func TestAnOptionalVerbStaysOptionalInASetReadFromTheStore(t *testing.T) {
+	defer UseSeats(DefaultSeats())
+	var rows []Seat
+	for _, s := range DefaultSeats() {
+		row := s
+		row.Serves = nil
+		for _, v := range s.Serves {
+			row.Serves = append(row.Serves, Verb{Name: v.Name, Description: v.Description, Input: v.Input})
+		}
+		rows = append(rows, row)
+	}
+	UseSeats(rows)
+	seat, _ := SeatNamed(ServiceManagerSeat)
+	holder := Manifest{Module: "systemd", Version: "1", Claims: []Claim{{Name: ServiceManagerSeat, Scope: ScopeNode,
+		Serves: []string{"units", "status", "start", "stop", "restart", "enable", "disable", "journal"}}}}
+	if err := CanHold(holder, seat); err != nil {
+		t.Fatalf("a set read from rows refuses today's holder: %v", err)
+	}
+}

internal/catalogue/seats.go

@@ -338,12 +338,35 @@ func UseSeats(s []Seat) {
 		if d, known := byName[row.Name]; known {
 			row.Receives = d.Receives
 			row.Replicated = d.Replicated
+			row.Serves = optionalAsCompiled(row.Serves, d.Serves)
 		}
 		merged = append(merged, row)
 	}
 	seats = merged
 }
 
+// optionalAsCompiled is a row's verbs with each one the compiled seat marks optional marked so. The mark
+// is never stored (Verb.Optional), and a row is what the working set holds once the store is read: a verb
+// the seeding added to the row — `failed`, `checks` — would otherwise come back required, and every holder
+// not serving it yet would be refused at registration and at handover, which the mark exists to prevent.
+func optionalAsCompiled(row, compiled []Verb) []Verb {
+	optional := map[string]bool{}
+	for _, v := range compiled {
+		if v.Optional {
+			optional[v.Name] = true
+		}
+	}
+	if len(optional) == 0 {
+		return row
+	}
+	out := make([]Verb, len(row))
+	for i, v := range row {
+		v.Optional = optional[v.Name]
+		out[i] = v
+	}
+	return out
+}
+
 // aliases maps a seat's former names to its current canonical name (novox/hq ADR 0122). Loaded from
 // the store alongside the set, so a reference to a name a seat used to have — a manifest's claim, a
 // held record — still resolves to it after a rename, and nothing downstream has to change.
@@ -562,7 +585,7 @@ func SeatsWithAProtocol() []Seat {
 // 0177): the units on the machine in both scopes, read and acted on by name. Every verb takes an
 // optional scope — "system" when absent, "user" for the operator account's own manager — so a
 // caller asks for a user unit the way it asks for a system one; `failed` alone reads both managers
-// when none is named.
+// when none is named, and is optional (Verb.Optional).
 func serviceManagerVerbs() []Verb {
 	scoped := func(more map[string]string, required []string) map[string]any {
 		props := map[string]string{"scope": "\"system\" (the default) or \"user\": the operator account's own manager"}
@@ -603,8 +626,10 @@ func serviceManagerVerbs() []Verb {
 				"priority": "only entries this severe or more: 0-7 or emerg, alert, crit, err, warning, notice, info, debug (optional)",
 			}, []string{"unit"})},
 		// What has failed, on the seat rather than as one holder's own tool: whatever holds the role answers
-		// it, so a caller asks every machine the same way.
-		{Name: "failed", Description: "Every failed unit on this machine, in the system manager and in the operator " +
+		// it, so a caller asks every machine the same way. **Optional while its holders catch up**: the
+		// systemd module running today serves it as its own systemd_failed, and a required verb would
+		// refuse it before the version serving `failed` could be delivered.
+		{Name: "failed", Optional: true, Description: "Every failed unit on this machine, in the system manager and in the operator " +
 			"account's; a manager that does not answer is reported with its error, never as nothing failed.",
 			Input: schema(map[string]string{"scope": "\"system\" or \"user\": only that manager (both when absent)"}, nil)},
 	}

internal/inventory/seats.go

@@ -126,6 +126,16 @@ func (i *Inventory) widenProtocol(ctx context.Context, s catalogue.Seat) error {
 		if s.Name == catalogue.ControllerSeatName && !sameVerb(row.Serves[at], v) {
 			row.Serves[at] = v
 			changed = true
+			continue
+		}
+		// **Any other seat's verb gains the arguments the binary names and the row lacks** — additive,
+		// as the rest of the protocol is. The console refuses an argument the row does not name (issue
+		// 244), so a holder taught a new argument (the service manager's journal window) would be
+		// unreachable through it while the row kept the older schema. Nothing the row has is removed or
+		// made required; the description is the binary's, since it describes the arguments added.
+		if widened, ok := widenInput(row.Serves[at], v); ok {
+			row.Serves[at] = widened
+			changed = true
 		}
 	}
 	if !changed {
@@ -296,6 +306,45 @@ func (i *Inventory) Holdings(ctx context.Context) ([]catalogue.Held, error) {
 	return out, rows.Err()
 }
 
+// widenInput is the row's verb with every input property the binary's names and the row's lacks, and
+// the binary's description; and whether anything was added.
+func widenInput(row, binary catalogue.Verb) (catalogue.Verb, bool) {
+	want, _ := binary.Input["properties"].(map[string]any)
+	if len(want) == 0 {
+		return row, false
+	}
+	have, _ := row.Input["properties"].(map[string]any)
+	added := map[string]any{}
+	for name, p := range want {
+		if _, kept := have[name]; !kept {
+			added[name] = p
+		}
+	}
+	if len(added) == 0 {
+		return row, false
+	}
+	input := map[string]any{}
+	for k, v := range row.Input {
+		input[k] = v
+	}
+	if input["type"] == nil {
+		input["type"] = "object"
+	}
+	props := map[string]any{}
+	for k, v := range have {
+		props[k] = v
+	}
+	for k, v := range added {
+		props[k] = v
+	}
+	input["properties"] = props
+	row.Input = input
+	if binary.Description != "" {
+		row.Description = binary.Description
+	}
+	return row, true
+}
+
 // sameVerb is whether two definitions of a verb say the same, read as the row stores them.
 func sameVerb(a, b catalogue.Verb) bool {
 	ja, errA := json.Marshal(a)

internal/inventory/seats_test.go

@@ -156,3 +156,74 @@ func TestTheControllersVerbsInTheRowAreTheBinarys(t *testing.T) {
 		t.Fatal("a verb this binary adds was not added")
 	}
 }
+
+// **A seat's verb gains the arguments a newer binary names** (the service manager's journal window,
+// 2026-10-07): the console refuses an argument the row does not name, so a row seeded before them would
+// keep the holder's new arguments unreachable. Added, never removed — an argument only the row has stays,
+// and nothing becomes required — and a verb the binary adds optional is optional in the working set read back.
+func TestASeatsVerbGainsTheArgumentsTheBinaryNames(t *testing.T) {
+	inv := ForTest(t)
+	ctx := t.Context()
+	if _, err := inv.SeedSeats(ctx, catalogue.DefaultSeats()); err != nil {
+		t.Fatal(err)
+	}
+	old := `[{"name":"journal","description":"The last lines of one unit's journal.","input":{"type":"object",
+	          "properties":{"unit":{"type":"string"},"lines":{"type":"string"},"scope":{"type":"string"},"kept":{"type":"string"}},
+	          "required":["unit"]}}]`
+	if _, err := inv.store.Pool().Exec(ctx, `update seat set serves = $1 where name = $2`,
+		[]byte(old), catalogue.ServiceManagerSeat); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := inv.SeedSeats(ctx, catalogue.DefaultSeats()); err != nil {
+		t.Fatal(err)
+	}
+	seats, err := inv.Seats(ctx)
+	if err != nil {
+		t.Fatal(err)
+	}
+	verbs := map[string]catalogue.Verb{}
+	for _, s := range seats {
+		if s.Name == catalogue.ServiceManagerSeat {
+			for _, v := range s.Serves {
+				verbs[v.Name] = v
+			}
+		}
+	}
+	props, _ := verbs["journal"].Input["properties"].(map[string]any)
+	for _, arg := range []string{"since", "until", "match", "priority", "unit", "lines", "scope", "kept"} {
+		if _, has := props[arg]; !has {
+			t.Errorf("journal in the row does not take %s: %v", arg, props)
+		}
+	}
+	if req, _ := verbs["journal"].Input["required"].([]any); len(req) != 1 || req[0] != "unit" {
+		t.Errorf("what journal requires changed: %v", verbs["journal"].Input["required"])
+	}
+	if _, added := verbs["failed"]; !added {
+		t.Fatal("failed was not added to the row")
+	}
+	// The optional mark is not stored; the working set read from the rows takes it from the compiled seat,
+	// so today's holder, which does not serve failed, still holds the seat.
+	catalogue.UseSeats(seats)
+	defer catalogue.UseSeats(catalogue.DefaultSeats())
+	live, _ := catalogue.SeatNamed(catalogue.ServiceManagerSeat)
+	holder := catalogue.Manifest{Module: "systemd", Version: "1", Claims: []catalogue.Claim{{Name: catalogue.ServiceManagerSeat,
+		Scope: catalogue.ScopeNode, Serves: []string{"units", "status", "start", "stop", "restart", "enable", "disable", "journal"}}}}
+	if err := catalogue.CanHold(holder, live); err != nil {
+		t.Fatalf("the seat read from the store refuses today's holder: %v", err)
+	}
+	// Seeding again changes nothing more.
+	before := verbs["journal"]
+	if _, err := inv.SeedSeats(ctx, catalogue.DefaultSeats()); err != nil {
+		t.Fatal(err)
+	}
+	after, _ := inv.Seats(ctx)
+	for _, s := range after {
+		if s.Name == catalogue.ServiceManagerSeat {
+			for _, v := range s.Serves {
+				if v.Name == "journal" && !sameVerb(v, before) {
+					t.Fatalf("re-seeding changed journal again: %+v", v)
+				}
+			}
+		}
+	}
+}