diff --git a/cmd/bd/mol_test.go b/cmd/bd/mol_test.go
index a8d18728..4c84fd8a 100644
--- a/cmd/bd/mol_test.go
+++ b/cmd/bd/mol_test.go
@@ -2364,3 +2364,166 @@ func TestCalculateBlockingDepths(t *testing.T) {
 		t.Errorf("step3 depth = %d, want 3", depths["step3"])
 	}
 }
+
+// TestSpawnMoleculeEphemeralFlag verifies that spawnMolecule with ephemeral=true
+// creates issues with the Ephemeral flag set (bd-phin)
+func TestSpawnMoleculeEphemeralFlag(t *testing.T) {
+	ctx := context.Background()
+	dbPath := t.TempDir() + "/test.db"
+	s, err := sqlite.New(ctx, dbPath)
+	if err != nil {
+		t.Fatalf("Failed to create store: %v", err)
+	}
+	defer s.Close()
+	if err := s.SetConfig(ctx, "issue_prefix", "test"); err != nil {
+		t.Fatalf("Failed to set config: %v", err)
+	}
+
+	// Create a template with a child (IDs will be auto-generated)
+	root := &types.Issue{
+		Title:      "Template Epic",
+		Status:     types.StatusOpen,
+		Priority:   2,
+		IssueType:  types.TypeEpic,
+		Labels:     []string{MoleculeLabel}, // Required for loadTemplateSubgraph
+	}
+	child := &types.Issue{
+		Title:      "Template Task",
+		Status:     types.StatusOpen,
+		Priority:   2,
+		IssueType:  types.TypeTask,
+	}
+
+	if err := s.CreateIssue(ctx, root, "test"); err != nil {
+		t.Fatalf("Failed to create template root: %v", err)
+	}
+	if err := s.CreateIssue(ctx, child, "test"); err != nil {
+		t.Fatalf("Failed to create template child: %v", err)
+	}
+
+	// Add parent-child dependency
+	if err := s.AddDependency(ctx, &types.Dependency{
+		IssueID:     child.ID,
+		DependsOnID: root.ID,
+		Type:        types.DepParentChild,
+	}, "test"); err != nil {
+		t.Fatalf("Failed to add parent-child dependency: %v", err)
+	}
+
+	// Load subgraph
+	subgraph, err := loadTemplateSubgraph(ctx, s, root.ID)
+	if err != nil {
+		t.Fatalf("Failed to load subgraph: %v", err)
+	}
+
+	// Spawn with ephemeral=true
+	result, err := spawnMolecule(ctx, s, subgraph, nil, "", "test", true, "eph")
+	if err != nil {
+		t.Fatalf("spawnMolecule failed: %v", err)
+	}
+
+	// Verify all spawned issues have Ephemeral=true
+	for oldID, newID := range result.IDMapping {
+		spawned, err := s.GetIssue(ctx, newID)
+		if err != nil {
+			t.Fatalf("Failed to get spawned issue %s: %v", newID, err)
+		}
+		if !spawned.Ephemeral {
+			t.Errorf("Spawned issue %s (from %s) should have Ephemeral=true, got false", newID, oldID)
+		}
+	}
+
+	// Verify spawned issues have the correct prefix
+	for _, newID := range result.IDMapping {
+		if !strings.HasPrefix(newID, "test-eph-") {
+			t.Errorf("Spawned issue ID %s should have prefix 'test-eph-'", newID)
+		}
+	}
+}
+
+// TestSpawnMoleculeFromFormulaEphemeral verifies that spawning from a cooked formula
+// with ephemeral=true creates issues with the Ephemeral flag set (bd-phin)
+func TestSpawnMoleculeFromFormulaEphemeral(t *testing.T) {
+	ctx := context.Background()
+	dbPath := t.TempDir() + "/test.db"
+	s, err := sqlite.New(ctx, dbPath)
+	if err != nil {
+		t.Fatalf("Failed to create store: %v", err)
+	}
+	defer s.Close()
+	if err := s.SetConfig(ctx, "issue_prefix", "test"); err != nil {
+		t.Fatalf("Failed to set config: %v", err)
+	}
+
+	// Create a minimal in-memory subgraph (simulating cookFormulaToSubgraph output)
+	root := &types.Issue{
+		ID:          "test-formula",
+		Title:       "Test Formula",
+		Status:      types.StatusOpen,
+		Priority:    2,
+		IssueType:   types.TypeEpic,
+		IsTemplate:  true,
+	}
+	step := &types.Issue{
+		ID:          "test-formula.step1",
+		Title:       "Step 1",
+		Status:      types.StatusOpen,
+		Priority:    2,
+		IssueType:   types.TypeTask,
+		IsTemplate:  true,
+	}
+	
+	subgraph := &TemplateSubgraph{
+		Root:   root,
+		Issues: []*types.Issue{root, step},
+		Dependencies: []*types.Dependency{
+			{
+				IssueID:     step.ID,
+				DependsOnID: root.ID,
+				Type:        types.DepParentChild,
+			},
+		},
+		IssueMap: map[string]*types.Issue{
+			root.ID: root,
+			step.ID: step,
+		},
+	}
+
+	// Spawn with ephemeral=true (simulating bd mol wisp <formula>)
+	result, err := spawnMolecule(ctx, s, subgraph, nil, "", "test", true, "eph")
+	if err != nil {
+		t.Fatalf("spawnMolecule failed: %v", err)
+	}
+
+	// Verify all spawned issues have Ephemeral=true
+	for oldID, newID := range result.IDMapping {
+		spawned, err := s.GetIssue(ctx, newID)
+		if err != nil {
+			t.Fatalf("Failed to get spawned issue %s: %v", newID, err)
+		}
+		if !spawned.Ephemeral {
+			t.Errorf("Spawned issue %s (from %s) should have Ephemeral=true, got false", newID, oldID)
+		}
+		t.Logf("Issue %s: Ephemeral=%v", newID, spawned.Ephemeral)
+	}
+
+	// Verify they have the correct prefix
+	for _, newID := range result.IDMapping {
+		if !strings.HasPrefix(newID, "test-eph-") {
+			t.Errorf("Spawned issue ID %s should have prefix 'test-eph-'", newID)
+		}
+	}
+
+	// Verify ephemeral issues are excluded from ready work
+	readyWork, err := s.GetReadyWork(ctx, types.WorkFilter{})
+	if err != nil {
+		t.Fatalf("GetReadyWork failed: %v", err)
+	}
+	for _, issue := range readyWork {
+		for _, spawnedID := range result.IDMapping {
+			if issue.ID == spawnedID {
+				t.Errorf("Ephemeral issue %s should not appear in ready work", spawnedID)
+			}
+		}
+	}
+}