fix

cmd/checkout/pool-server.go

@@ -452,13 +452,21 @@ func (s *CheckoutPoolServer) StartPaymentHandler(w http.ResponseWriter, r *http.
 			logger.Error("unable to create adyen session", "error", err)
 			return err
 		}
-
+		sessionBytes, err := json.Marshal(session)
+		if err != nil {
+			logger.Error("unable to marshal session", "error", err)
+			return err
+		}
 		// Apply PaymentStarted mutation
 		_, err = s.ApplyLocal(r.Context(), checkoutId, &messages.PaymentStarted{
 			PaymentId: session.Id,
 			Amount:    session.Amount.Value,
 			Currency:  session.Amount.Currency,
 			Provider:  "adyen",
+			SessionData: &anypb.Any{
+				TypeUrl: "type.googleapis.com/google.protobuf.StringValue",
+				Value:   sessionBytes,
+			},
 			Method:    &payload.Method,
 			StartedAt: timestamppb.New(time.Now()),
 		})
@@ -475,12 +483,21 @@ func (s *CheckoutPoolServer) StartPaymentHandler(w http.ResponseWriter, r *http.
 			logger.Error("unable to create klarna session", "error", err)
 			return err
 		}
+		orderBytes, err := json.Marshal(order)
+		if err != nil {
+			logger.Error("unable to marshal order", "error", err)
+			return err
+		}
 		_, err = s.ApplyLocal(r.Context(), checkoutId, &messages.PaymentStarted{
 			PaymentId: order.ID,
 			Amount:    int64(order.OrderAmount),
 			Currency:  order.PurchaseCurrency,
 			Provider:  "klarna",
 			Method:    &payload.Method,
+			SessionData: &anypb.Any{
+				TypeUrl: "type.googleapis.com/google.protobuf.StringValue",
+				Value:   orderBytes,
+			},
 			StartedAt: timestamppb.New(time.Now()),
 		})
 		if err != nil {