diff --git a/modules/mesh-delivery-pipeline/internal/pipeline/place.go b/modules/mesh-delivery-pipeline/internal/pipeline/place.go
index a5b08a48..3a89ddd8 100644
--- a/modules/mesh-delivery-pipeline/internal/pipeline/place.go
+++ b/modules/mesh-delivery-pipeline/internal/pipeline/place.go
@@ -11,6 +11,7 @@ import (
 	builds "git.novox.be/novox/mesh-delivery/contracts/go/seats/meshbuilds"
 	catalog "git.novox.be/novox/mesh-delivery/contracts/go/seats/meshcatalog"
 	seat "git.novox.be/novox/mesh-delivery/contracts/go/seats/meshpipelinerunner"
+	wants "git.novox.be/novox/mesh-delivery/contracts/go/seats/meshwants"
 	nodebuildgo "git.novox.be/novox/mesh-delivery/contracts/go/seats/nodebuildgo"
 	nodebuildimage "git.novox.be/novox/mesh-delivery/contracts/go/seats/nodebuildimage"
 	nodebuildnode "git.novox.be/novox/mesh-delivery/contracts/go/seats/nodebuildnode"
@@ -25,6 +26,7 @@ type StepAsker interface {
 // acceptStep is where each build seat is sent its step, from its contract.
 var acceptStep = map[string]string{
 	builds.Seat:         builds.AcceptSubjectStep,
+	wants.Seat:          wants.AcceptSubjectStep,
 	nodebuildgo.Seat:    nodebuildgo.AcceptSubjectCheckStep,
 	nodebuildnode.Seat:  nodebuildnode.AcceptSubjectCheckStep,
 	nodebuildimage.Seat: nodebuildimage.AcceptSubjectCheckStep,
@@ -106,6 +108,14 @@ func Place(p seat.Pipeline, reg catalog.Registration, entries map[string]catalog
 		if status == seat.StepResultStatusBypass {
 			s.Outcome, s.Why = seat.StepResultOutcomeBypassed, "bypassed by the module's policy"
 		}
+		// Composition is the assigner's, an accepted kind step of the seat mesh-wants (§22): it is asked with the others,
+		// running at once, and its end is heard from that seat as the build seats' are. Review and approval wait.
+		if step == seat.StepResultStepComposition && status != seat.StepResultStatusBypass {
+			s.Seat, s.Outcome, s.Started, s.Fingerprint = wants.Seat, seat.StepResultOutcomeRunning, &now, p.Fingerprint
+			s.Ask = AskID(p.Pipeline, "", step)
+			asks = append(asks, Asked{Seat: wants.Seat, ID: s.Ask, Ask: wants.StepRun{Branch: p.Branch, Commit: p.Commit, Fingerprint: p.Fingerprint,
+				Module: p.Module, Pipeline: p.Pipeline, Revision: p.Revision, Source: p.Source, Step: wants.StepRunStepComposition}})
+		}
 		steps = append(steps, s)
 	}
 	return steps, asks
diff --git a/modules/mesh-delivery-pipeline/internal/pipeline/place_test.go b/modules/mesh-delivery-pipeline/internal/pipeline/place_test.go
index 52dbf3ff..e8a98929 100644
--- a/modules/mesh-delivery-pipeline/internal/pipeline/place_test.go
+++ b/modules/mesh-delivery-pipeline/internal/pipeline/place_test.go
@@ -4,13 +4,26 @@ import (
 	"encoding/json"
 	"strings"
 	"testing"
+	"time"
 
 	builds "git.novox.be/novox/mesh-delivery/contracts/go/seats/meshbuilds"
 	catalog "git.novox.be/novox/mesh-delivery/contracts/go/seats/meshcatalog"
 	seat "git.novox.be/novox/mesh-delivery/contracts/go/seats/meshpipelinerunner"
+	wants "git.novox.be/novox/mesh-delivery/contracts/go/seats/meshwants"
 	nodebuildgo "git.novox.be/novox/mesh-delivery/contracts/go/seats/nodebuildgo"
 )
 
+func stepSeatOf(t *testing.T, name string) StepSeat {
+	t.Helper()
+	for _, bs := range StepSeats {
+		if bs.Seat == name {
+			return bs
+		}
+	}
+	t.Fatalf("no step seat %s", name)
+	return StepSeat{}
+}
+
 type stepAsks struct {
 	at   []string
 	ids  []string
@@ -105,10 +118,7 @@ func TestTheBuildHoldsTheApprovalWhateverThePolicyNames(t *testing.T) {
 // The seat mesh-builds' end of the build step is taken as the others are, held to its one entry's module, commit and
 // fingerprint; an end naming two entries is refused (A-97, A-99).
 func TestTheBuildStepsEndIsTakenOnItsOneEntry(t *testing.T) {
-	bs := StepSeats[len(StepSeats)-1]
-	if bs.Seat != builds.Seat {
-		t.Fatalf("the last step seat is %s, want mesh-builds", bs.Seat)
-	}
+	bs := stepSeatOf(t, builds.Seat)
 	h, store, _, _, _, _ := fixture()
 	e := store[pkey]
 	e.p.Steps = append([]seat.StepResult{{Step: seat.StepResultStepBuild, Status: seat.StepResultStatusRequired, Outcome: seat.StepResultOutcomeRunning,
@@ -127,3 +137,38 @@ func TestTheBuildStepsEndIsTakenOnItsOneEntry(t *testing.T) {
 		t.Error("an end of two entries is refused")
 	}
 }
+
+// Composition is asked of the seat mesh-wants with the other steps, running at once, and its end is heard from that seat
+// (design 47 G §22, §24): a pipeline whose policy names it places it running with its own ask, a bypassed one asks no one.
+func TestCompositionIsAskedOfTheAssignerAndItsEndIsTaken(t *testing.T) {
+	reg, entries := placeFixture()
+	reg.Policy = catalog.Policy{Steps: catalog.StepStatuses{Lint: "bypass", Unit: "bypass", Composition: "required", Approval: "required"}}
+	p := seat.Pipeline{Pipeline: "main.4.app", Branch: "main", Module: "app", Commit: "c1", Fingerprint: "src2:aa", Revision: 7, Source: 4}
+	steps, asked := Place(p, reg, entries, time.Unix(1, 0), "the-runner")
+	var comp seat.StepResult
+	for _, s := range steps {
+		if s.Step == seat.StepResultStepComposition {
+			comp = s
+		}
+	}
+	if comp.Outcome != seat.StepResultOutcomeRunning || comp.Seat != wants.Seat || comp.Ask == "" {
+		t.Fatalf("composition = %+v, want running, asked of mesh-wants", comp)
+	}
+	var got *Asked
+	for i := range asked {
+		if asked[i].Seat == wants.Seat {
+			got = &asked[i]
+		}
+	}
+	r, ok := got.Ask.(wants.StepRun)
+	if got == nil || !ok || got.ID != comp.Ask || acceptStep[wants.Seat] != wants.AcceptSubjectStep || r.Step != "composition" ||
+		r.Commit != "c1" || r.Fingerprint != "src2:aa" || r.Pipeline != "main.4.app" || r.Revision != 7 || r.Source != 4 || r.Module != "app" {
+		t.Fatalf("the composition ask = %+v", got)
+	}
+	// Its end, from the seat's own subject, is taken like the others, a node's warning becoming the step's why.
+	bs := stepSeatOf(t, wants.Seat)
+	ev, err := bs.Decode([]byte(`{"id":"` + comp.Ask + `","pipeline":"main.5.app","step":"composition","module":"app","commit":"c1","fingerprint":"src2:aa","node":"n1","outcome":"passed","warnings":["n2 asleep"]}`))
+	if err != nil || ev.Said != "n2 asleep" || ev.Outcome != "passed" || ev.Module != "app" {
+		t.Fatalf("decoded end = %+v, %v", ev, err)
+	}
+}
diff --git a/modules/mesh-delivery-pipeline/internal/pipeline/steps.go b/modules/mesh-delivery-pipeline/internal/pipeline/steps.go
index 28b676c5..4781a04d 100644
--- a/modules/mesh-delivery-pipeline/internal/pipeline/steps.go
+++ b/modules/mesh-delivery-pipeline/internal/pipeline/steps.go
@@ -10,6 +10,7 @@ import (
 	oc "git.novox.be/novox/mesh-contracts/operator-and-conversation/go/seats/operatorchannel"
 	builds "git.novox.be/novox/mesh-delivery/contracts/go/seats/meshbuilds"
 	seat "git.novox.be/novox/mesh-delivery/contracts/go/seats/meshpipelinerunner"
+	wants "git.novox.be/novox/mesh-delivery/contracts/go/seats/meshwants"
 	nodebuildgo "git.novox.be/novox/mesh-delivery/contracts/go/seats/nodebuildgo"
 	nodebuildimage "git.novox.be/novox/mesh-delivery/contracts/go/seats/nodebuildimage"
 	nodebuildnode "git.novox.be/novox/mesh-delivery/contracts/go/seats/nodebuildnode"
@@ -33,6 +34,23 @@ var StepSeats = []StepSeat{
 	{Seat: nodebuildimage.Seat, Prefix: strings.TrimSuffix(nodebuildimage.SubjectStepEndedAll, "*")},
 	// The seat mesh-builds answers the build step of a candidate, one entry named by its fingerprint (A-97, A-99).
 	{Seat: builds.Seat, Prefix: strings.TrimSuffix(builds.SubjectStepEndedAll, "*"), Decode: decodeBuildEnded},
+	// The seat mesh-wants answers the composition step (§22, §24).
+	{Seat: wants.Seat, Prefix: strings.TrimSuffix(wants.SubjectStepEndedAll, "*"), Decode: decodeWantsEnded},
+}
+
+// decodeWantsEnded reads the composition step's end of the seat mesh-wants as the form the hearer holds each end to; a
+// warning of a node asleep (a pass with a warning, ADR 0593 §9) is the step's `why` when the end says nothing else.
+func decodeWantsEnded(raw []byte) (StepEnded, error) {
+	var w wants.StepEnded
+	if err := json.Unmarshal(raw, &w); err != nil {
+		return StepEnded{}, err
+	}
+	said := w.Said
+	if said == "" && len(w.Warnings) > 0 {
+		said = strings.Join(w.Warnings, "; ")
+	}
+	return StepEnded{V: w.V, ID: w.ID, Pipeline: w.Pipeline, Step: w.Step, Module: w.Module, Commit: w.Commit, Fingerprint: w.Fingerprint,
+		Node: w.Node, Outcome: w.Outcome, Said: said, Rerun: w.Rerun, By: w.By, Started: w.Started, Ended: w.Ended}, nil
 }
 
 // decodeBuildEnded reads the build step's end of the seat mesh-builds as the form the hearer holds each end to: its one