diff --git a/internal/orchestrator/orchestrator.go b/internal/orchestrator/orchestrator.go
index 12b95b2..c76d451 100644
--- a/internal/orchestrator/orchestrator.go
+++ b/internal/orchestrator/orchestrator.go
@@ -175,6 +175,25 @@ type SessionHealth struct {
 	LastError          string    `json:"last_error,omitempty"`
 }
 
+// adapterFor resolves the herdr adapter for a session. Session.HerdrID (the
+// registered herdr instance id, e.g. "homesrv-claude") is authoritative;
+// Session.Harness (the harness kind, e.g. "claude") is only a fallback for
+// sessions persisted before HerdrID was tracked. Adapters are keyed by
+// instance id, so falling back to the lease's harness id (recorded on the
+// task) rather than the kind keeps this resolvable even then.
+func (c *Coordinator) adapterFor(taskID string, session herdr.Session) (herdr.Adapter, error) {
+	id := session.HerdrID
+	if id == "" {
+		if task, ok := c.Store.Task(taskID); ok && task.Lease != nil {
+			id = task.Lease.HarnessID
+		}
+	}
+	if id == "" {
+		id = session.Harness
+	}
+	return c.Adapters.Adapter(id)
+}
+
 func (c *Coordinator) MonitorHealth() MonitorHealth {
 	c.healthMu.RLock()
 	defer c.healthMu.RUnlock()
@@ -218,13 +237,7 @@ func (c *Coordinator) refreshSessionHealth(ctx context.Context) {
 	}
 	c.healthMu.Unlock()
 	for taskID, session := range sessions {
-		adapterID := session.HerdrID
-		if adapterID == "" {
-			if task, ok := c.Store.Task(taskID); ok && task.Lease != nil {
-				adapterID = task.Lease.HarnessID
-			}
-		}
-		a, err := c.Adapters.Adapter(adapterID)
+		a, err := c.adapterFor(taskID, session)
 		if err != nil {
 			continue
 		}
@@ -288,7 +301,7 @@ func (c *Coordinator) Reconcile(ctx context.Context) error {
 		if ok && t.State == domain.StateLeased {
 			continue
 		}
-		if a, err := c.Adapters.Adapter(session.Harness); err == nil {
+		if a, err := c.adapterFor(taskID, session); err == nil {
 			_ = a.Kill(ctx, session)
 		}
 		delete(c.sessions, taskID)
@@ -373,7 +386,7 @@ func (c *Coordinator) expire(ctx context.Context) ([]domain.Event, error) {
 	c.mu.Lock()
 	for taskID, s := range c.sessions {
 		if t, ok := c.Store.Task(taskID); ok && t.State == domain.StateLeased {
-			if a, ae := c.Adapters.Adapter(s.Harness); ae == nil {
+			if a, ae := c.adapterFor(taskID, s); ae == nil {
 				if p, ok := a.(herdr.PaneExit); ok {
 					if exited, ee := p.PaneExited(ctx, s); ee == nil && exited {
 						b, _ := json.Marshal(map[string]string{"reason": "pane_exited", "harness_id": s.Harness})
@@ -394,7 +407,7 @@ func (c *Coordinator) expire(ctx context.Context) ([]domain.Event, error) {
 		s, ok := c.sessions[e.TaskID]
 		delete(c.sessions, e.TaskID)
 		if ok {
-			if a, ae := c.Adapters.Adapter(s.Harness); ae == nil {
+			if a, ae := c.adapterFor(e.TaskID, s); ae == nil {
 				_ = a.Kill(ctx, s)
 			}
 		}
@@ -416,7 +429,7 @@ func (c *Coordinator) rotate(ctx context.Context, hard float64) {
 		if !ok || task.State != domain.StateLeased {
 			continue
 		}
-		a, err := c.Adapters.Adapter(session.Harness)
+		a, err := c.adapterFor(taskID, session)
 		if err != nil {
 			continue
 		}
diff --git a/internal/orchestrator/rotation_test.go b/internal/orchestrator/rotation_test.go
index b2fc42f..a2b8737 100644
--- a/internal/orchestrator/rotation_test.go
+++ b/internal/orchestrator/rotation_test.go
@@ -136,6 +136,76 @@ func TestRotationEmitsValidReleaseWithAnchorSHA(t *testing.T) {
 
 func mustJSON(v any) []byte { b, _ := json.Marshal(v); return b }
 
+// keyedHarnessAdapter reports Session.Harness as the harness kind ("claude"),
+// distinct from the herdr instance id ("homesrv-claude") under which it is
+// registered in AdapterFactory.Herdrs — reproducing production's real key
+// mismatch (adapters are keyed by herdr instance id; CLIAdapter.Lease sets
+// Session.Harness to the harness kind).
+type keyedHarnessAdapter struct{ fakeAdapter }
+
+func (a *keyedHarnessAdapter) Lease(_ context.Context, _ string, worktree string) (herdr.Session, error) {
+	return herdr.Session{Harness: "claude", PaneID: "pane-1", Worktree: worktree}, nil
+}
+
+// TestAdapterResolvedByHerdrIDNotHarnessKind guards B2: AdapterFactory.Herdrs
+// is keyed by herdr instance id (e.g. "homesrv-claude"), never by the
+// harness kind Session.Harness holds (e.g. "claude"). Reconcile, expire, and
+// rotate must all resolve the adapter via Session.HerdrID (set at lease
+// time), not Session.Harness, or every one of them silently no-ops via a
+// bare Adapter-not-registered continue.
+func TestAdapterResolvedByHerdrIDNotHarnessKind(t *testing.T) {
+	repo := t.TempDir()
+	run(t, repo, "init")
+	run(t, repo, "config", "user.email", "t@t")
+	run(t, repo, "config", "user.name", "t")
+	run(t, repo, "commit", "--allow-empty", "-m", "init")
+
+	s, err := store.Open(t.TempDir())
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := s.Append(domain.Event{ID: domain.NewID(), Type: "TaskCreated", TaskID: "t1", Surface: string(authz.System), Payload: mustJSON(map[string]any{
+		"source": "jsonl", "external_id": "1", "project": "p",
+	})}); err != nil {
+		t.Fatal(err)
+	}
+	task := s.Tasks()[0]
+	ref, err := s.PutArtifact([]byte("handoff"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	a := &keyedHarnessAdapter{fakeAdapter{occupancy: .95, boundary: true, ref: ref}}
+	factory := orchestrator.AdapterFactory{Herdrs: map[string]herdr.Adapter{"homesrv-claude": a}}
+	c := &orchestrator.Coordinator{Store: s, Worktrees: worktrees{path: repo}, Adapters: factory, StatePath: t.TempDir() + "/sessions.json"}
+
+	leaseEvt, err := s.Lease(task.ID, "homesrv-claude", time.Minute)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := c.Start(context.Background(), leaseEvt); err != nil {
+		t.Fatal(err)
+	}
+
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	go c.Monitor(ctx, .8, time.Millisecond)
+
+	deadline := time.Now().Add(time.Second)
+	for time.Now().Before(deadline) {
+		if got, ok := s.Task(task.ID); ok && got.State == domain.StateQueued {
+			break
+		}
+		time.Sleep(time.Millisecond)
+	}
+	got, ok := s.Task(task.ID)
+	if !ok || got.State != domain.StateQueued {
+		t.Fatalf("rotation did not complete via herdr-id-keyed adapter: state=%v ok=%v", got.State, ok)
+	}
+	if a.releases == 0 {
+		t.Fatalf("adapter Release was never invoked — adapter lookup used Session.Harness instead of Session.HerdrID")
+	}
+}
+
 // erroringBoundaryAdapter supports Face B but its probe always fails — this
 // must block release (never silently treat an unanswerable boundary check
 // as safe to interrupt), unlike an adapter that doesn't implement the