diff --git a/go/catalogue/checker_seat.go b/go/catalogue/checker_seat.go
new file mode 100644
index 0000000..30e8468
--- /dev/null
+++ b/go/catalogue/checker_seat.go
@@ -0,0 +1,32 @@
+package catalogue
+
+// The delivery's checker (novox/hq ADR 0547 §10, issue 774): one holder for the mesh, the module
+// mesh-delivery-checker, which judges a pull request's head and a pushed head the same way. The try the
+// controller forwarded to it is a verb of this seat, answered by the checker with the verdict it gives a pull
+// request, so the try outlives the controller.
+
+// CheckerSeat is the seat mesh-delivery-checker holds.
+const CheckerSeat = "mesh-delivery-checker"
+
+// checkerVerbs are the checker seat's verbs: ask a try, read one. Optional until the checker serves them
+// everywhere.
+func checkerVerbs() []Verb {
+	return []Verb{
+		{Name: "try", Optional: true, Description: "Try a pushed head before its pull request is opened: the checker " +
+			"judges it as it judges a pull request's head, merged onto its trunk's head, its unit and integration " +
+			"levels through the build modules, and owes the forge nothing. Answers the try's id at once; try-read " +
+			"reads where it stands. A try of the same head that waits or runs is the answer to a second ask; at most " +
+			"4 wait or run at once, mesh-wide.",
+			Input: schema(map[string]string{"repository": "<owner>/<name>",
+				"head":  "the full commit to try, 40 or 64 hex digits",
+				"trunk": "the trunk commit to merge it onto, or the trunk's branch for its head now; the trunk's head when absent",
+				"tests": "a go test -run pattern: only those tests run, and nothing is kept",
+				"level": "unit or integration: only this level; both when absent"},
+				[]string{"repository", "head"}),
+			Replaces: []string{"sh merge-check.sh"}},
+		{Name: "try-read", Optional: true, Description: "Where a try stands, as stored: queued, running, or its end " +
+			"(pass, fail, or error when it could not run), with what was said of it, the head and the trunk commit " +
+			"it was merged onto, the time it took and what failed first. Read-only.",
+			Input: schema(map[string]string{"id": "the try's id, try-<digits>"}, []string{"id"})},
+	}
+}
diff --git a/go/catalogue/checker_seat_test.go b/go/catalogue/checker_seat_test.go
new file mode 100644
index 0000000..f714337
--- /dev/null
+++ b/go/catalogue/checker_seat_test.go
@@ -0,0 +1,29 @@
+package catalogue
+
+import (
+	"slices"
+	"testing"
+)
+
+// The try is a verb of the checker's seat and carries the shell command it replaces (ADR 0547 §10, ADR 0245).
+func TestTheCheckerSeatServesTheTry(t *testing.T) {
+	var seat *Seat
+	for _, s := range defaultSeats {
+		if s.Name == CheckerSeat {
+			seat = &s
+		}
+	}
+	if seat == nil || seat.Scope != ScopeMesh {
+		t.Fatalf("seat = %+v", seat)
+	}
+	var names []string
+	for _, v := range seat.Serves {
+		names = append(names, v.Name)
+		if v.Name == "try" && !slices.Equal(v.Replaces, []string{"sh merge-check.sh"}) {
+			t.Errorf("try replaces %v", v.Replaces)
+		}
+	}
+	if !slices.Equal(names, []string{"try", "try-read"}) {
+		t.Errorf("verbs = %v", names)
+	}
+}
diff --git a/go/catalogue/seats.go b/go/catalogue/seats.go
index a6588d6..4ab81dc 100644
--- a/go/catalogue/seats.go
+++ b/go/catalogue/seats.go
@@ -265,6 +265,8 @@ var defaultSeats = append([]Seat{
 	// Placement (novox/hq ADR 0567): which module runs on which node, state on the bus held by the assigner, changed only by
 	// a proposal the nodes answer and the operator approves. Its states and events are the holder module's.
 	{Name: PlacementSeat, Scope: ScopeMesh, Serves: placementVerbs(), Decision: "novox/hq ADR 0567"},
+	// The delivery's checker (novox/hq ADR 0547 §10, issue 774): the try is its verb, not the controller's.
+	{Name: CheckerSeat, Scope: ScopeMesh, Serves: checkerVerbs(), Decision: "novox/hq ADR 0547"},
 	// Deferred renames (novox/hq ADR 0121): these deliver a provision, so renaming them is a
 	// delivering-seat migration with a mesh-wide cascade if a holder stops resolving mid-flight.
 	// They keep their names until that migration is done deliberately, apart from the node-* pass.
diff --git a/go/catalogue/seats_test.go b/go/catalogue/seats_test.go
index 6f58a11..3144c31 100644
--- a/go/catalogue/seats_test.go
+++ b/go/catalogue/seats_test.go
@@ -62,8 +62,9 @@ func TestTheSeatsAreAClosedSetAndEachNamesItsDecision(t *testing.T) {
 	// node-container-runtime (ADR 0207); nineteen with node-environment and node-login-shell (ADR 0203,
 	// ADR 0204); seventeen with node-build-agent (ADR 0190). One fewer once the retired
 	// mesh-build-machine row goes, when no registered manifest claims it.
-	if len(Seats()) != 47 {
-		t.Errorf("the mesh defines %d seats rather than 47; the set is closed, so a change here is "+
+	// Forty-eight with mesh-delivery-checker (novox/hq ADR 0547 §10, issue 774).
+	if len(Seats()) != 48 {
+		t.Errorf("the mesh defines %d seats rather than 48; the set is closed, so a change here is "+
 			"a decision (novox/hq ADR 0110): %s", len(Seats()), seatNames())
 	}
 }