diff --git a/internal/selfcompose/kept_test.go b/internal/selfcompose/kept_test.go
index c5eea439..4ef6f1d5 100644
--- a/internal/selfcompose/kept_test.go
+++ b/internal/selfcompose/kept_test.go
@@ -2,9 +2,11 @@ package selfcompose
 
 import (
 	"context"
+	"slices"
 	"strings"
 	"testing"
 
+	"git.novox.be/novox/mesh-delivery/modules/mesh-delivery-contracts/go/seats/meshcatalog"
 	"git.novox.be/novox/mesh-delivery/modules/mesh-delivery-contracts/go/seats/meshwants"
 )
 
@@ -33,3 +35,20 @@ func TestTheKeepingNodeIsTheWantsKeptOn(t *testing.T) {
 		}
 	}
 }
+
+// Design 47 G §558, A-275: a manifest's `invokes` in its long form {verb, fields} is read for its seat, and one of a form that
+// cannot be read is refused, never read as no seats.
+func TestSeatsOfReadsALongFormInvokeAndRefusesAnUnreadableOne(t *testing.T) {
+	c := New(Env{Node: "n1"})
+	c.modules["m"] = meshcatalog.ModulesByModuleValue{Manifest: "d1"}
+	c.modules["bad"] = meshcatalog.ModulesByModuleValue{Manifest: "d2"}
+	c.manifests["d1"] = []byte(`{"module":"m","invokes":["seat:a.b",{"verb":"seat:mesh-catalog.revision","fields":["x"]}]}`)
+	c.manifests["d2"] = []byte(`{"module":"bad","invokes":[3]}`)
+	seats, err := c.seatsOf(context.Background(), reader{c: c}, "m")
+	if err != nil || !slices.Equal(seats, []string{"a", "mesh-catalog"}) {
+		t.Fatalf("seats %v, %v", seats, err)
+	}
+	if seats, err := c.seatsOf(context.Background(), reader{c: c}, "bad"); err == nil {
+		t.Fatalf("an unreadable invokes gave seats %v", seats)
+	}
+}
diff --git a/internal/selfcompose/selfcompose.go b/internal/selfcompose/selfcompose.go
index 2b60ca71..a5dcd90c 100644
--- a/internal/selfcompose/selfcompose.go
+++ b/internal/selfcompose/selfcompose.go
@@ -2035,7 +2035,7 @@ func (c *Composer) heldUntilListed(ctx context.Context, r reader, own meshmodule
 	held := map[string]string{}
 	for _, pm := range own.Modules {
 		if pm.Module == "" || pm.Module == agent.NodeModule || slices.Contains(holders, pm.Module) ||
-			c.env.SeatList.MayAct(c.seatsOf(ctx, r, pm.Module)...) {
+			c.mayAct(ctx, r, pm.Module) {
 			continue
 		}
 		held[pm.Module] = line + composesNothingNewOfIt
@@ -2094,7 +2094,7 @@ func (c *Composer) holdUntilListed(ctx context.Context, r reader, compositions m
 				held[module] = WaitsForTheSeatListOwnPart
 				continue
 			}
-		} else if c.env.SeatList.MayAct(c.seatsOf(ctx, r, module)...) {
+		} else if c.mayAct(ctx, r, module) {
 			continue
 		}
 		delete(compositions, key)
@@ -2207,41 +2207,55 @@ func (c *Composer) claimants(ctx context.Context, r reader, seat string) []strin
 	return out
 }
 
-// seatsOf is the seats a module claims, invokes or provides, from the manifest its module record names; none when it
-// cannot be read, which the reader judges as a module no bootstrapped seat names.
-func (c *Composer) seatsOf(ctx context.Context, r reader, module string) []string {
+// mayAct is whether the seat list lets module act: of the seats it claims or invokes (seatsOf). A manifest whose `invokes`
+// is of a form that cannot be read is refused, never read as no seats (design 47 G A-275).
+func (c *Composer) mayAct(ctx context.Context, r reader, module string) bool {
+	seats, err := c.seatsOf(ctx, r, module)
+	if err != nil {
+		return false // refused: held with the module's other waits, never judged as no seats
+	}
+	return c.env.SeatList.MayAct(seats...)
+}
+
+// seatsOf is the seats a module claims or invokes, from the manifest its module record names; none when it cannot be
+// fetched, which the reader judges as a module no bootstrapped seat names, and an error when its manifest is of a form that
+// cannot be read (design 47 G §558, A-275).
+func (c *Composer) seatsOf(ctx context.Context, r reader, module string) ([]string, error) {
 	c.mu.Lock()
 	m, ok := c.modules[module]
 	c.mu.Unlock()
 	if !ok || m.Manifest == "" {
-		return nil
+		return nil, nil
 	}
 	raw, err := r.Manifest(ctx, m.Manifest)
 	if err != nil {
-		return nil
+		return nil, nil
 	}
 	var man struct {
 		Claims []struct {
 			Name string `json:"name"`
 		} `json:"claims"`
-		Invokes  []string `json:"invokes"`
-		Provides []struct {
-			Name string `json:"name"`
-		} `json:"provides"`
+		Invokes json.RawMessage `json:"invokes"`
 	}
-	if json.Unmarshal(raw, &man) != nil {
-		return nil
+	if err := json.Unmarshal(raw, &man); err != nil {
+		return nil, fmt.Errorf("the manifest of %s cannot be read: %w", module, err)
+	}
+	var invokes []string
+	if len(man.Invokes) > 0 {
+		if invokes, err = catalogue.InvokedVerbs(man.Invokes); err != nil {
+			return nil, fmt.Errorf("the manifest of %s: %w", module, err)
+		}
 	}
 	var seats []string
 	for _, cl := range man.Claims {
 		seats = append(seats, cl.Name)
 	}
-	for _, in := range man.Invokes {
+	for _, in := range invokes {
 		if seat, _, ok := strings.Cut(strings.TrimPrefix(in, "seat:"), "."); ok && strings.HasPrefix(in, "seat:") {
 			seats = append(seats, seat)
 		}
 	}
-	return seats
+	return seats, nil
 }
 
 // unmadeOf is each module wanted at a fingerprint (fps) of which the pass made no composition at it, with why, apart from