diff --git a/cmd/mesh-host/nodeagent_integration_test.go b/cmd/mesh-host/nodeagent_integration_test.go
index cecee45..f6f15d3 100644
--- a/cmd/mesh-host/nodeagent_integration_test.go
+++ b/cmd/mesh-host/nodeagent_integration_test.go
@@ -603,7 +603,7 @@ func h8candidate(t *testing.T, b *itBed, fp, running string) {
 		t.Fatalf("the answer %s: %v", raw, err)
 	}
 	if a.Verdict != delivery.ComposeCandidateComposed || len(a.Modules) != 1 || a.Modules[0].Module != "web" ||
-		a.Modules[0].FP != fpIt("c") || !a.Modules[0].Changed || a.Took > delivery.ComposeAnswerBound.Milliseconds() {
+		a.Modules[0].Fp != fpIt("c") || !a.Modules[0].Changed || a.Took > delivery.ComposeAnswerBound.Milliseconds() {
 		t.Errorf("the node's answer to a candidate changing web: %+v", a)
 	}
 	after, _ := b.composed.Status()
diff --git a/internal/selfcompose/candidate.go b/internal/selfcompose/candidate.go
index 1176808..f38037b 100644
--- a/internal/selfcompose/candidate.go
+++ b/internal/selfcompose/candidate.go
@@ -1,6 +1,7 @@
 package selfcompose
 
 import (
+	"bytes"
 	"context"
 	"encoding/json"
 	"errors"
@@ -181,6 +182,7 @@ func (s *Shadow) composeCandidate(ctx context.Context, c *Composer, ask delivery
 	if err != nil {
 		return unready(err.Error())
 	}
+	sentSize := 0
 	laidComps, laidHeld, laidErr := laid.composeShadow(ctx, running, touched, func(scope frombus.Scope, fps map[string]string) {
 		if !ask.Input {
 			return
@@ -196,13 +198,19 @@ func (s *Shadow) composeCandidate(ctx context.Context, c *Composer, ask delivery
 		in.ComposedHow.HeldBefore = maps.Clone(baseHeld)
 		// As the sandbox reads it (composer.SentInput, the one shape): this node's own modules as taken in from their
 		// builds, every other module's manifest left to the cases.
+		// The seat's contract carries it as a JSON object; its numbers are kept as written (json.Number).
 		if body, err := json.Marshal(composer.SentInput(in, laid.env.Node)); err == nil {
-			a.Input = body
+			d := json.NewDecoder(bytes.NewReader(body))
+			d.UseNumber()
+			var obj map[string]any
+			if d.Decode(&obj) == nil {
+				a.Input, sentSize = obj, len(body)
+			}
 		}
 	})
-	if len(a.Input) > maxSentInput {
+	if sentSize > maxSentInput {
 		// Past what the bus carries in one answer, the checker would hear nothing: refused, saying so.
-		size := len(a.Input)
+		size := sentSize
 		a.Input = nil
 		return refuse(fmt.Sprintf("the composition input this node composed from is %d bytes, more than the %d an answer on the bus carries", size, maxSentInput))
 	}
@@ -251,7 +259,7 @@ func (s *Shadow) composeCandidate(ctx context.Context, c *Composer, ask delivery
 			m.State, m.Words = delivery.ModuleRefusedState, err.Error()
 			return m, true
 		}
-		m.State, m.FP, m.Digest = delivery.ModuleComposedState, comp.FP, dig
+		m.State, m.Fp, m.Digest = delivery.ModuleComposedState, comp.FP, dig
 		if before, ok := was[module]; !ok {
 			m.Changed = true
 		} else if d, err := delivery.ComposedDigestOf(before); err != nil || d != dig {
diff --git a/internal/selfcompose/candidate_test.go b/internal/selfcompose/candidate_test.go
index ea78e81..e3cc8ae 100644
--- a/internal/selfcompose/candidate_test.go
+++ b/internal/selfcompose/candidate_test.go
@@ -103,7 +103,7 @@ func TestTheNodeComposesACandidateOnAsk(t *testing.T) {
 		t.Fatalf("the answer does not fit the seat's shape: %v (%+v)", err, a)
 	}
 	if a.Verdict != delivery.ComposeCandidateComposed || len(a.Modules) != 1 || a.Modules[0].Module != "lemurs" ||
-		a.Modules[0].State != delivery.ModuleComposedState || a.Modules[0].FP != fpNew || !a.Modules[0].Changed ||
+		a.Modules[0].State != delivery.ModuleComposedState || a.Modules[0].Fp != fpNew || !a.Modules[0].Changed ||
 		a.Own.Module != delivery.HaveNodeWord || a.Took > delivery.ComposeAnswerBound.Milliseconds() {
 		t.Errorf("an accepted candidate answered %+v", a)
 	}
@@ -111,7 +111,8 @@ func TestTheNodeComposesACandidateOnAsk(t *testing.T) {
 	// through the same path.
 	sent := s.ComposeCandidate(ctx, delivery.ComposeCandidateAsk{Candidate: accepted, Input: true})
 	var in compose.Input
-	if err := json.Unmarshal(sent.Input, &in); err != nil || in.ComposedHow == nil || in.ComposedHow.Node != "n1" ||
+	raw, _ := json.Marshal(sent.Input)
+	if err := json.Unmarshal(raw, &in); err != nil || in.ComposedHow == nil || in.ComposedHow.Node != "n1" ||
 		in.ComposedHow.Builds["lemurs"] != fpNew {
 		t.Errorf("the input sent for the sandbox does not say how the node composes: %+v, %v", in.ComposedHow, err)
 	}