diff --git a/internal/compose/frombus/frombustest/seats_for_tests_test.go b/internal/compose/frombus/frombustest/seats_for_tests_test.go
new file mode 100644
index 0000000..2700f7c
--- /dev/null
+++ b/internal/compose/frombus/frombustest/seats_for_tests_test.go
@@ -0,0 +1,10 @@
+package frombustest
+
+import (
+	"git.novox.be/novox/mesh-sdk/go/catalogue"
+	"git.novox.be/novox/mesh-sdk/go/seatlist/seatlisttest"
+)
+
+// The seats the tests judge against are given to catalogue as the node-engine gives the ones it read from the bus
+// (novox/hq ADR 0635 §1); catalogue compiles none.
+func init() { catalogue.UseSeats(catalogue.SeatsFromDefinitions(seatlisttest.Definitions())) }
diff --git a/internal/compose/frombus/seats_for_tests_test.go b/internal/compose/frombus/seats_for_tests_test.go
new file mode 100644
index 0000000..16c5987
--- /dev/null
+++ b/internal/compose/frombus/seats_for_tests_test.go
@@ -0,0 +1,10 @@
+package frombus
+
+import (
+	"git.novox.be/novox/mesh-sdk/go/catalogue"
+	"git.novox.be/novox/mesh-sdk/go/seatlist/seatlisttest"
+)
+
+// The seats the tests judge against are given to catalogue as the node-engine gives the ones it read from the bus
+// (novox/hq ADR 0635 §1); catalogue compiles none.
+func init() { catalogue.UseSeats(catalogue.SeatsFromDefinitions(seatlisttest.Definitions())) }
diff --git a/internal/compose/resolution/files_test.go b/internal/compose/resolution/files_test.go
index 4d8ed14..625f40d 100644
--- a/internal/compose/resolution/files_test.go
+++ b/internal/compose/resolution/files_test.go
@@ -42,12 +42,13 @@ func TestTheHolderOfNodeFilesIsToldSecretPlacesAndOwnedPaths(t *testing.T) {
 		Resources: []map[string]any{{"id": "stub", "type": "file", "path": mcat.ResolverFile}}}
 	uplink := mcat.Manifest{Module: "networkmanager", Version: "1", Claims: []mcat.Claim{{Name: "node-uplink"}},
 		Resources: []map[string]any{{"id": "resolv", "type": "file", "path": mcat.ResolverFile}}}
-	compiled := seats
-	t.Cleanup(func() { seats = compiled })
+	compiled := mcat.Seats()
+	t.Cleanup(func() { mcat.UseSeats(compiled) })
 	for _, order := range []string{"compiled", "reversed"} {
 		if order == "reversed" {
-			seats = append([]mcat.Seat(nil), compiled...)
-			slices.Reverse(seats)
+			reversed := append([]mcat.Seat(nil), compiled...)
+			slices.Reverse(reversed)
+			mcat.UseSeats(reversed)
 		}
 		both := mcat.Resolution{Node: "anchor", Modules: []mcat.Manifest{files, uplink, resolver}}
 		w, err := resolutionFilesWords(both, files, nil, mcat.Rendering{})
@@ -59,7 +60,7 @@ func TestTheHolderOfNodeFilesIsToldSecretPlacesAndOwnedPaths(t *testing.T) {
 			t.Errorf("seat table %s: %s is owned by %q, want systemd-resolved (%s)", order, mcat.ResolverFile, o[mcat.ResolverFile], mcat.ResolverSeat)
 		}
 	}
-	seats = compiled
+	mcat.UseSeats(compiled)
 	// Issue 1126, C5 and seed-8: a module carried as it runs (compose.Carried) owns its manifest's paths (OwnsPaths), as
 	// the controller tells them, and not the paths its running resources are at (a directory the mesh placed).
 	carried := mcat.Manifest{Module: "de-spiegel", Version: "1", OwnsPaths: []string{"/var/lib/de-spiegel/server.env"},
diff --git a/internal/compose/resolution/seats.go b/internal/compose/resolution/seats.go
index 1420499..8813719 100644
--- a/internal/compose/resolution/seats.go
+++ b/internal/compose/resolution/seats.go
@@ -4,16 +4,6 @@ import (
 	mcat "git.novox.be/novox/mesh-sdk/go/catalogue"
 )
 
-// defaultSeats is the set the mesh ships with — the seed for the control plane's seat table and the fallback when it has none
-// (novox/hq ADR 0122). It is mesh-contracts' generated list, as mesh-sdk compiles it, taken whole: the node-engine keeps no copy of
-// a seat's verbs or events (design 26, ADR 0608 §5; issue 1966 ENG-3).
-var defaultSeats = mcat.DefaultSeats()
-
-// seats is the working set the lookups read. It starts as the compiled defaults and is replaced by
-// what the control plane loaded from its store (novox/hq ADR 0122), so a change to the set is a
-// change to data, not to this code.
-var seats = defaultSeats
-
 // configInput is the schema of mesh-config's verb: a value of the key's own type (a number for a number, never its
 // text), and a limit that is a number; every other argument a string.
 func configInput() map[string]any {
diff --git a/internal/compose/resolution/seats_for_tests_test.go b/internal/compose/resolution/seats_for_tests_test.go
new file mode 100644
index 0000000..ef33ada
--- /dev/null
+++ b/internal/compose/resolution/seats_for_tests_test.go
@@ -0,0 +1,10 @@
+package resolution
+
+import (
+	"git.novox.be/novox/mesh-sdk/go/catalogue"
+	"git.novox.be/novox/mesh-sdk/go/seatlist/seatlisttest"
+)
+
+// The seats the tests judge against are given to catalogue as the node-engine gives the ones it read from the bus
+// (novox/hq ADR 0635 §1); catalogue compiles none.
+func init() { catalogue.UseSeats(catalogue.SeatsFromDefinitions(seatlisttest.Definitions())) }
diff --git a/internal/compose/resolution/seats_test.go b/internal/compose/resolution/seats_test.go
index bcbac2c..4a72341 100644
--- a/internal/compose/resolution/seats_test.go
+++ b/internal/compose/resolution/seats_test.go
@@ -1,7 +1,6 @@
 package resolution
 
 import (
-	"reflect"
 	"strings"
 	"testing"
 
@@ -71,22 +70,4 @@ func TestTheHolderIsTheModuleNotTheMachine(t *testing.T) {
 		t.Fatalf("the holder was not told apart from a neighbour: %+v", holder)
 	}
 
-	// ADR 0604 section 1, F3: the seat table written here answers as the SDK's does for the catalog seat, its four
-	// verbs included, so no two copies of the table disagree.
-	want, ok := mcat.SeatNamed(mcat.CatalogSeat)
-	if !ok {
-		t.Fatal("the SDK holds no catalog seat")
-	}
-	var have *mcat.Seat
-	for i := range defaultSeats {
-		if defaultSeats[i].Name == mcat.CatalogSeat {
-			have = &defaultSeats[i]
-		}
-	}
-	if have == nil {
-		t.Fatal("the table here holds no catalog seat")
-	}
-	if !reflect.DeepEqual(*have, want) {
-		t.Errorf("the table here has %+v, the SDK's is %+v", *have, want)
-	}
 }
diff --git a/internal/compose/seats_for_tests_test.go b/internal/compose/seats_for_tests_test.go
new file mode 100644
index 0000000..c6afc26
--- /dev/null
+++ b/internal/compose/seats_for_tests_test.go
@@ -0,0 +1,10 @@
+package compose
+
+import (
+	"git.novox.be/novox/mesh-sdk/go/catalogue"
+	"git.novox.be/novox/mesh-sdk/go/seatlist/seatlisttest"
+)
+
+// The seats the tests judge against are given to catalogue as the node-engine gives the ones it read from the bus
+// (novox/hq ADR 0635 §1); catalogue compiles none.
+func init() { catalogue.UseSeats(catalogue.SeatsFromDefinitions(seatlisttest.Definitions())) }
diff --git a/internal/composer/seats_for_tests_test.go b/internal/composer/seats_for_tests_test.go
new file mode 100644
index 0000000..5415dc6
--- /dev/null
+++ b/internal/composer/seats_for_tests_test.go
@@ -0,0 +1,10 @@
+package composer
+
+import (
+	"git.novox.be/novox/mesh-sdk/go/catalogue"
+	"git.novox.be/novox/mesh-sdk/go/seatlist/seatlisttest"
+)
+
+// The seats the tests judge against are given to catalogue as the node-engine gives the ones it read from the bus
+// (novox/hq ADR 0635 §1); catalogue compiles none.
+func init() { catalogue.UseSeats(catalogue.SeatsFromDefinitions(seatlisttest.Definitions())) }
diff --git a/internal/link/engineseat.go b/internal/link/engineseat.go
index 5256348..4d47ace 100644
--- a/internal/link/engineseat.go
+++ b/internal/link/engineseat.go
@@ -9,6 +9,7 @@ import (
 	"strings"
 	"time"
 
+	"git.novox.be/novox/mesh-contracts/go/seats/nodeengine"
 	oc "git.novox.be/novox/mesh-contracts/go/seats/operatorchannel"
 	stdio "git.novox.be/novox/mesh-sdk/go"
 	"git.novox.be/novox/mesh-sdk/go/catalogue"
@@ -25,7 +26,7 @@ import (
 // tool's (mesh-tools node-tools). One service, `node-engine`, answers discovery with each verb's seat, tool and node.
 
 // EngineSeat is the seat.
-const EngineSeat = catalogue.EngineSeat
+const EngineSeat = nodeengine.Seat
 
 // EngineToolSubject is where a verb of this node's seat is asked naming no caller.
 func EngineToolSubject(verb, node string) string {
@@ -117,7 +118,7 @@ func (l *natsLink) ServeEngineSeat(handle EngineFunc) {
 		return
 	}
 	apart := make(chan struct{}, apartAtOnce)
-	for _, v := range catalogue.EngineVerbs() {
+	for _, v := range catalogue.EngineVerbs(EngineSeat) {
 		verb := v.Name
 		answer := EngineAnswer(handle, verb, l.node, apart)
 		meta := EngineEndpointMetadata(v, l.node)