diff --git a/pkg/backofficeadmin/app.go b/pkg/backofficeadmin/app.go
index 5cb6217..a38230c 100644
--- a/pkg/backofficeadmin/app.go
+++ b/pkg/backofficeadmin/app.go
@@ -58,9 +58,10 @@ type Config struct {
 // App is the commerce admin control plane. Construct with New, register its
 // HTTP surface with RegisterRoutes, run background work with Start.
 type App struct {
-	fs  *FileServer
-	hub *Hub
-	cs  *CustomerServer
+	fs               *FileServer
+	hub              *Hub
+	cs               *CustomerServer
+	OnVouchersChange func(codes []string)
 }
 
 // New constructs the commerce admin: it opens the cart/checkout disk event-log
@@ -171,6 +172,7 @@ func New(cfg Config) (*App, error) {
 // apply auth or CORS — the composing host (or standalone main) wraps the mux
 // with those.
 func (a *App) RegisterRoutes(mux *http.ServeMux) {
+	a.fs.OnVouchersChange = a.OnVouchersChange
 	mux.HandleFunc("GET /carts", a.fs.CartsHandler)
 	mux.HandleFunc("GET /cart/{id}", a.fs.CartHandler)
 	mux.HandleFunc("GET /checkouts", a.fs.CheckoutsHandler)
diff --git a/pkg/backofficeadmin/fileserver.go b/pkg/backofficeadmin/fileserver.go
index f267737..9f4766d 100644
--- a/pkg/backofficeadmin/fileserver.go
+++ b/pkg/backofficeadmin/fileserver.go
@@ -24,11 +24,12 @@ import (
 
 type FileServer struct {
 	// Define fields here
-	dataDir         string
-	checkoutDataDir string
-	promotionsFile  string
-	storage         actor.LogStorage[cart.CartGrain]
-	checkoutStorage actor.LogStorage[checkout.CheckoutGrain]
+	dataDir          string
+	checkoutDataDir  string
+	promotionsFile   string
+	storage          actor.LogStorage[cart.CartGrain]
+	checkoutStorage  actor.LogStorage[checkout.CheckoutGrain]
+	OnVouchersChange func(codes []string)
 }
 
 func NewFileServer(dataDir string, checkoutDataDir string, promotionsFile string, storage actor.LogStorage[cart.CartGrain], checkoutStorage actor.LogStorage[checkout.CheckoutGrain]) *FileServer {
@@ -276,15 +277,37 @@ func (fs *FileServer) VoucherHandler(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 	if r.Method == http.MethodPost {
-		_ = os.MkdirAll(filepath.Dir(fileName), 0755)
-		file, err := os.Create(fileName)
+		body, err := io.ReadAll(r.Body)
 		if err != nil {
 			writeJSON(w, http.StatusInternalServerError, map[string]string{"error": err.Error()})
 			return
 		}
-		defer file.Close()
 
-		io.Copy(file, r.Body)
+		var parsed struct {
+			State struct {
+				Vouchers []struct {
+					Code string `json:"code"`
+				} `json:"vouchers"`
+			} `json:"state"`
+		}
+		var codes []string
+		if err := json.Unmarshal(body, &parsed); err == nil {
+			for _, v := range parsed.State.Vouchers {
+				if v.Code != "" {
+					codes = append(codes, v.Code)
+				}
+			}
+		}
+
+		_ = os.MkdirAll(filepath.Dir(fileName), 0755)
+		if err := os.WriteFile(fileName, body, 0644); err != nil {
+			writeJSON(w, http.StatusInternalServerError, map[string]string{"error": err.Error()})
+			return
+		}
+
+		if fs.OnVouchersChange != nil {
+			fs.OnVouchersChange(codes)
+		}
 		return
 	}
 
diff --git a/pkg/promotions/store.go b/pkg/promotions/store.go
index 976f223..adf7541 100644
--- a/pkg/promotions/store.go
+++ b/pkg/promotions/store.go
@@ -18,6 +18,7 @@ type Store struct {
 	path       string
 	version    int
 	promotions []PromotionRule
+	OnChange   func(id string, isDelete bool)
 }
 
 // NewStore loads the state file at path (an absent file yields an empty store)
@@ -72,40 +73,72 @@ func (s *Store) Upsert(rule PromotionRule) (replaced bool, err error) {
 	if rule.ID == "" {
 		return false, fmt.Errorf("promotion id is required")
 	}
+	var cb func(string, bool)
 	s.mu.Lock()
-	defer s.mu.Unlock()
+	defer func() {
+		s.mu.Unlock()
+		if err == nil && cb != nil {
+			cb(rule.ID, false)
+		}
+	}()
+	cb = s.OnChange
+
 	for i := range s.promotions {
 		if s.promotions[i].ID == rule.ID {
 			s.promotions[i] = rule
-			return true, s.saveLocked()
+			replaced = true
+			err = s.saveLocked()
+			return
 		}
 	}
 	s.promotions = append(s.promotions, rule)
-	return false, s.saveLocked()
+	replaced = false
+	err = s.saveLocked()
+	return
 }
 
 // SetStatus changes the status of a rule and persists. Returns false if no rule
 // with the id exists.
-func (s *Store) SetStatus(id string, status PromotionStatus) (bool, error) {
+func (s *Store) SetStatus(id string, status PromotionStatus) (found bool, err error) {
+	var cb func(string, bool)
 	s.mu.Lock()
-	defer s.mu.Unlock()
+	defer func() {
+		s.mu.Unlock()
+		if err == nil && found && cb != nil {
+			cb(id, false)
+		}
+	}()
+	cb = s.OnChange
+
 	for i := range s.promotions {
 		if s.promotions[i].ID == id {
 			s.promotions[i].Status = status
-			return true, s.saveLocked()
+			found = true
+			err = s.saveLocked()
+			return
 		}
 	}
 	return false, nil
 }
 
 // Delete removes the rule with the id and persists. Returns false if not found.
-func (s *Store) Delete(id string) (bool, error) {
+func (s *Store) Delete(id string) (found bool, err error) {
+	var cb func(string, bool)
 	s.mu.Lock()
-	defer s.mu.Unlock()
+	defer func() {
+		s.mu.Unlock()
+		if err == nil && found && cb != nil {
+			cb(id, true)
+		}
+	}()
+	cb = s.OnChange
+
 	for i := range s.promotions {
 		if s.promotions[i].ID == id {
 			s.promotions = append(s.promotions[:i], s.promotions[i+1:]...)
-			return true, s.saveLocked()
+			found = true
+			err = s.saveLocked()
+			return
 		}
 	}
 	return false, nil