fixed mntx payout sequence

api/gateway/mntx/README.md

@@ -20,12 +20,15 @@ This service now supports Monetix “payout by card”.
 Payload is built per Monetix spec:
 ```
 {
-  "general":  { "project_id": <int>, "payment_id": "<payout_id>", "signature": "<hmac>" },
+  "general":  { "project_id": <int>, "payment_id": "<operation_ref>", "signature": "<hmac>" },
   "customer": { id, first_name, last_name, middle_name?, ip_address, zip?, country?, state?, city?, address? },
   "payment":  { amount: <minor_units>, currency: "<ISO-4217>" },
   "card":     { pan, year?, month?, card_holder }
 }
 ```
+Gateway request contract additionally requires `parent_payment_ref` as a first-class field
+(separate from Monetix `payment_id`).
+
 Signature: HMAC-SHA256 over the JSON body (without `signature`), using `MONETIX_SECRET_KEY`.
 
 ## Callback handling

api/gateway/mntx/client/client.go

@@ -39,8 +39,6 @@ type gatewayClient struct {
 	logger mlogger.Logger
 }
 
-const parentPaymentRefMetadataKey = "parent_payment_ref"
-
 // New dials the Monetix gateway.
 func New(ctx context.Context, cfg Config, opts ...grpc.DialOption) (Client, error) {
 	cfg.setDefaults()
@@ -106,7 +104,7 @@ func (g *gatewayClient) CreateCardPayout(ctx context.Context, req *mntxv1.CardPa
 	if resp.GetReceipt() != nil && resp.GetReceipt().GetError() != nil {
 		return nil, connectorError(resp.GetReceipt().GetError())
 	}
-	return &mntxv1.CardPayoutResponse{Payout: payoutFromReceipt(req.GetPayoutId(), req.GetOperationRef(), resp.GetReceipt())}, nil
+	return &mntxv1.CardPayoutResponse{Payout: payoutFromReceipt(req.GetPayoutId(), req.GetOperationRef(), req.GetParentPaymentRef(), resp.GetReceipt())}, nil
 }
 
 func (g *gatewayClient) CreateCardTokenPayout(ctx context.Context, req *mntxv1.CardTokenPayoutRequest) (*mntxv1.CardTokenPayoutResponse, error) {
@@ -123,7 +121,7 @@ func (g *gatewayClient) CreateCardTokenPayout(ctx context.Context, req *mntxv1.C
 	if resp.GetReceipt() != nil && resp.GetReceipt().GetError() != nil {
 		return nil, connectorError(resp.GetReceipt().GetError())
 	}
-	return &mntxv1.CardTokenPayoutResponse{Payout: payoutFromReceipt(req.GetPayoutId(), req.GetOperationRef(), resp.GetReceipt())}, nil
+	return &mntxv1.CardTokenPayoutResponse{Payout: payoutFromReceipt(req.GetPayoutId(), req.GetOperationRef(), req.GetParentPaymentRef(), resp.GetReceipt())}, nil
 }
 
 func (g *gatewayClient) GetCardPayoutStatus(ctx context.Context, req *mntxv1.GetCardPayoutStatusRequest) (*mntxv1.GetCardPayoutStatusResponse, error) {
@@ -200,9 +198,10 @@ func setOperationRolesFromMetadata(op *connectorv1.Operation, metadata map[strin
 }
 
 func payoutParamsFromCard(req *mntxv1.CardPayoutRequest) map[string]interface{} {
-	metadata := metadataWithParentPaymentRef(req.GetMetadata(), req.GetPayoutId())
+	metadata := sanitizeMetadata(req.GetMetadata())
 	params := map[string]interface{}{
 		"project_id":           req.GetProjectId(),
+		"parent_payment_ref":   strings.TrimSpace(req.GetParentPaymentRef()),
 		"customer_id":          strings.TrimSpace(req.GetCustomerId()),
 		"customer_first_name":  strings.TrimSpace(req.GetCustomerFirstName()),
 		"customer_middle_name": strings.TrimSpace(req.GetCustomerMiddleName()),
@@ -227,9 +226,10 @@ func payoutParamsFromCard(req *mntxv1.CardPayoutRequest) map[string]interface{}
 }
 
 func payoutParamsFromToken(req *mntxv1.CardTokenPayoutRequest) map[string]interface{} {
-	metadata := metadataWithParentPaymentRef(req.GetMetadata(), req.GetPayoutId())
+	metadata := sanitizeMetadata(req.GetMetadata())
 	params := map[string]interface{}{
 		"project_id":           req.GetProjectId(),
+		"parent_payment_ref":   strings.TrimSpace(req.GetParentPaymentRef()),
 		"customer_id":          strings.TrimSpace(req.GetCustomerId()),
 		"customer_first_name":  strings.TrimSpace(req.GetCustomerFirstName()),
 		"customer_middle_name": strings.TrimSpace(req.GetCustomerMiddleName()),
@@ -263,9 +263,10 @@ func moneyFromMinor(amount int64, currency string) *moneyv1.Money {
 	}
 }
 
-func payoutFromReceipt(payoutID, operationRef string, receipt *connectorv1.OperationReceipt) *mntxv1.CardPayoutState {
+func payoutFromReceipt(payoutID, operationRef, parentPaymentRef string, receipt *connectorv1.OperationReceipt) *mntxv1.CardPayoutState {
 	state := &mntxv1.CardPayoutState{
-		PayoutId: fallbackNonEmpty(operationRef, payoutID),
+		PayoutId:         fallbackNonEmpty(operationRef, payoutID),
+		ParentPaymentRef: strings.TrimSpace(parentPaymentRef),
 	}
 	if receipt == nil {
 		return state
@@ -288,9 +289,8 @@ func fallbackNonEmpty(values ...string) string {
 	return ""
 }
 
-func metadataWithParentPaymentRef(source map[string]string, parentPaymentRef string) map[string]string {
+func sanitizeMetadata(source map[string]string) map[string]string {
-	parentPaymentRef = strings.TrimSpace(parentPaymentRef)
+	if len(source) == 0 {
-	if len(source) == 0 && parentPaymentRef == "" {
 		return nil
 	}
 	out := map[string]string{}
@@ -301,9 +301,6 @@ func metadataWithParentPaymentRef(source map[string]string, parentPaymentRef str
 		}
 		out[k] = strings.TrimSpace(value)
 	}
-	if parentPaymentRef != "" && strings.TrimSpace(out[parentPaymentRefMetadataKey]) == "" {
-		out[parentPaymentRefMetadataKey] = parentPaymentRef
-	}
 	if len(out) == 0 {
 		return nil
 	}

api/gateway/mntx/internal/service/gateway/card_payout_handlers.go

@@ -22,6 +22,7 @@ func (s *Service) handleCreateCardPayout(ctx context.Context, req *mntxv1.CardPa
 	log.Info("Create card payout request received",
 		zap.String("payout_id", strings.TrimSpace(req.GetPayoutId())),
 		zap.String("operation_ref", strings.TrimSpace(req.GetOperationRef())),
+		zap.String("parent_payment_ref", strings.TrimSpace(req.GetParentPaymentRef())),
 		zap.String("customer_id", strings.TrimSpace(req.GetCustomerId())),
 		zap.Int64("amount_minor", req.GetAmountMinor()),
 		zap.String("currency", strings.ToUpper(strings.TrimSpace(req.GetCurrency()))),
@@ -49,6 +50,7 @@ func (s *Service) handleCreateCardTokenPayout(ctx context.Context, req *mntxv1.C
 	log.Info("Create card token payout request received",
 		zap.String("payout_id", strings.TrimSpace(req.GetPayoutId())),
 		zap.String("operation_ref", strings.TrimSpace(req.GetOperationRef())),
+		zap.String("parent_payment_ref", strings.TrimSpace(req.GetParentPaymentRef())),
 		zap.String("customer_id", strings.TrimSpace(req.GetCustomerId())),
 		zap.Int64("amount_minor", req.GetAmountMinor()),
 		zap.String("currency", strings.ToUpper(strings.TrimSpace(req.GetCurrency()))),
@@ -122,6 +124,7 @@ func sanitizeCardPayoutRequest(req *mntxv1.CardPayoutRequest) *mntxv1.CardPayout
 		return req
 	}
 	r.PayoutId = strings.TrimSpace(r.GetPayoutId())
+	r.ParentPaymentRef = strings.TrimSpace(r.GetParentPaymentRef())
 	r.CustomerId = strings.TrimSpace(r.GetCustomerId())
 	r.CustomerFirstName = strings.TrimSpace(r.GetCustomerFirstName())
 	r.CustomerMiddleName = strings.TrimSpace(r.GetCustomerMiddleName())
@@ -151,6 +154,7 @@ func sanitizeCardTokenPayoutRequest(req *mntxv1.CardTokenPayoutRequest) *mntxv1.
 		return req
 	}
 	r.PayoutId = strings.TrimSpace(r.GetPayoutId())
+	r.ParentPaymentRef = strings.TrimSpace(r.GetParentPaymentRef())
 	r.CustomerId = strings.TrimSpace(r.GetCustomerId())
 	r.CustomerFirstName = strings.TrimSpace(r.GetCustomerFirstName())
 	r.CustomerMiddleName = strings.TrimSpace(r.GetCustomerMiddleName())

api/gateway/mntx/internal/service/gateway/card_payout_validation.go

@@ -17,6 +17,9 @@ func validateCardPayoutRequest(req *mntxv1.CardPayoutRequest, cfg monetix.Config
 	if err := validateOperationIdentity(strings.TrimSpace(req.GetPayoutId()), strings.TrimSpace(req.GetOperationRef())); err != nil {
 		return err
 	}
+	if strings.TrimSpace(req.GetParentPaymentRef()) == "" {
+		return newPayoutError("missing_parent_payment_ref", merrors.InvalidArgument("parent_payment_ref is required", "parent_payment_ref"))
+	}
 	if strings.TrimSpace(req.GetCustomerId()) == "" {
 		return newPayoutError("missing_customer_id", merrors.InvalidArgument("customer_id is required", "customer_id"))
 	}

api/gateway/mntx/internal/service/gateway/card_payout_validation_test.go

@@ -28,6 +28,11 @@ func TestValidateCardPayoutRequest_Errors(t *testing.T) {
 			mutate:   func(r *mntxv1.CardPayoutRequest) { r.PayoutId = "" },
 			expected: "missing_operation_ref",
 		},
+		{
+			name:     "missing_parent_payment_ref",
+			mutate:   func(r *mntxv1.CardPayoutRequest) { r.ParentPaymentRef = "" },
+			expected: "missing_parent_payment_ref",
+		},
 		{
 			name: "both_operation_and_payout_identity",
 			mutate: func(r *mntxv1.CardPayoutRequest) {

api/gateway/mntx/internal/service/gateway/card_processor.go

@@ -39,8 +39,6 @@ type cardPayoutProcessor struct {
 	perTxMinAmountMinorByCurrency map[string]int64
 }
 
-const parentPaymentRefMetadataKey = "parent_payment_ref"
-
 func mergePayoutStateWithExisting(state, existing *model.CardPayout) {
 	if state == nil || existing == nil {
 		return
@@ -59,7 +57,7 @@ func mergePayoutStateWithExisting(state, existing *model.CardPayout) {
 	if state.IntentRef == "" {
 		state.IntentRef = existing.IntentRef
 	}
-	if state.PaymentRef == "" {
+	if existing.PaymentRef != "" {
 		state.PaymentRef = existing.PaymentRef
 	}
 }
@@ -72,47 +70,6 @@ func findOperationRef(operationRef, payoutID string) string {
 	return strings.TrimSpace(payoutID)
 }
 
-func parentPaymentRefFromOperationRef(operationRef string) string {
-	ref := strings.TrimSpace(operationRef)
-	if ref == "" {
-		return ""
-	}
-	if idx := strings.Index(ref, ":hop_"); idx > 0 {
-		return ref[:idx]
-	}
-	if idx := strings.Index(ref, ":"); idx > 0 {
-		return ref[:idx]
-	}
-	return ""
-}
-
-func parentPaymentRefFromMetadata(metadata map[string]string) string {
-	if len(metadata) == 0 {
-		return ""
-	}
-	return strings.TrimSpace(metadata[parentPaymentRefMetadataKey])
-}
-
-func resolveParentPaymentRef(payoutID, operationRef string, metadata map[string]string) string {
-	if parent := parentPaymentRefFromMetadata(metadata); parent != "" {
-		return parent
-	}
-	payoutRef := strings.TrimSpace(payoutID)
-	opRef := strings.TrimSpace(operationRef)
-
-	// Legacy callers may pass parent payment ref via payout_id and a distinct operation_ref.
-	if payoutRef != "" && (opRef == "" || payoutRef != opRef) {
-		return payoutRef
-	}
-	if parent := parentPaymentRefFromOperationRef(opRef); parent != "" {
-		return parent
-	}
-	if payoutRef != "" {
-		return payoutRef
-	}
-	return opRef
-}
-
 func (p *cardPayoutProcessor) findExistingPayoutState(ctx context.Context, state *model.CardPayout) (*model.CardPayout, error) {
 	if p == nil || state == nil {
 		return nil, nil
@@ -129,23 +86,6 @@ func (p *cardPayoutProcessor) findExistingPayoutState(ctx context.Context, state
 				return nil, err
 			}
 		}
-		// Legacy mode may still map operation ref to payout/payment ref.
-		if paymentRef := strings.TrimSpace(state.PaymentRef); paymentRef == "" || paymentRef != opRef {
-			return nil, nil
-		}
-	}
-	if paymentRef := strings.TrimSpace(state.PaymentRef); paymentRef != "" {
-		existing, err := p.store.Payouts().FindByPaymentID(ctx, paymentRef)
-		if err == nil {
-			if existing != nil {
-				return existing, nil
-			}
-		}
-		if !errors.Is(err, merrors.ErrNoData) {
-			if err != nil {
-				return nil, err
-			}
-		}
 	}
 	return nil, nil
 }
@@ -310,7 +250,7 @@ func (p *cardPayoutProcessor) Submit(ctx context.Context, req *mntxv1.CardPayout
 
 	req = sanitizeCardPayoutRequest(req)
 	operationRef := findOperationRef(req.GetOperationRef(), req.GetPayoutId())
-	parentPaymentRef := resolveParentPaymentRef(req.GetPayoutId(), operationRef, req.GetMetadata())
+	parentPaymentRef := strings.TrimSpace(req.GetParentPaymentRef())
 
 	p.logger.Info("Submitting card payout",
 		zap.String("parent_payment_ref", parentPaymentRef),
@@ -435,7 +375,7 @@ func (p *cardPayoutProcessor) SubmitToken(ctx context.Context, req *mntxv1.CardT
 
 	req = sanitizeCardTokenPayoutRequest(req)
 	operationRef := findOperationRef(req.GetOperationRef(), req.GetPayoutId())
-	parentPaymentRef := resolveParentPaymentRef(req.GetPayoutId(), operationRef, req.GetMetadata())
+	parentPaymentRef := strings.TrimSpace(req.GetParentPaymentRef())
 
 	p.logger.Info("Submitting card token payout",
 		zap.String("parent_payment_ref", parentPaymentRef),
@@ -609,7 +549,7 @@ func (p *cardPayoutProcessor) Status(ctx context.Context, payoutID string) (*mnt
 	}
 
 	id := strings.TrimSpace(payoutID)
-	p.logger.Info("Card payout status requested", zap.String("operation_or_payout_id", id))
+	p.logger.Info("Card payout status requested", zap.String("operation_ref", id))
 
 	if id == "" {
 		p.logger.Warn("Payout status requested with empty payout_id")
@@ -622,11 +562,8 @@ func (p *cardPayoutProcessor) Status(ctx context.Context, payoutID string) (*mnt
 		return nil, err
 	}
 	if state == nil || errors.Is(err, merrors.ErrNoData) {
-		state, err = p.store.Payouts().FindByPaymentID(ctx, id)
+		p.logger.Warn("Payout status not found", zap.String("operation_ref", id))
-		if err != nil || state == nil {
+		return nil, merrors.NoData("payout not found")
-			p.logger.Warn("Payout status not found", zap.String("operation_or_payout_id", id), zap.Error(err))
-			return nil, merrors.NoData("payout not found")
-		}
 	}
 
 	p.logger.Info("Card payout status resolved",

api/gateway/mntx/internal/service/gateway/card_processor_test.go

@@ -5,6 +5,7 @@ import (
 	"context"
 	"encoding/json"
 	"errors"
+	"fmt"
 	"io"
 	"net/http"
 	"testing"
@@ -45,8 +46,9 @@ func TestCardPayoutProcessor_Submit_Success(t *testing.T) {
 
 	repo := newMockRepository()
 	repo.payouts.Save(&model.CardPayout{
-		PaymentRef: "payout-1",
+		PaymentRef:   "payment-parent-1",
-		CreatedAt:  existingCreated,
+		OperationRef: "payout-1",
+		CreatedAt:    existingCreated,
 	})
 
 	httpClient := &http.Client{
@@ -227,3 +229,173 @@ func TestCardPayoutProcessor_ProcessCallback(t *testing.T) {
 		t.Fatalf("expected success status in model, got %v", state.Status)
 	}
 }
+
+func TestCardPayoutProcessor_Submit_SameParentDifferentOperationsStoredSeparately(t *testing.T) {
+	cfg := monetix.Config{
+		BaseURL:           "https://monetix.test",
+		SecretKey:         "secret",
+		ProjectID:         99,
+		AllowedCurrencies: []string{"RUB"},
+	}
+
+	repo := newMockRepository()
+	var callN int
+	httpClient := &http.Client{
+		Transport: roundTripperFunc(func(r *http.Request) (*http.Response, error) {
+			callN++
+			resp := monetix.APIResponse{}
+			resp.Operation.RequestID = fmt.Sprintf("req-%d", callN)
+			body, _ := json.Marshal(resp)
+			return &http.Response{
+				StatusCode: http.StatusOK,
+				Body:       io.NopCloser(bytes.NewReader(body)),
+				Header:     http.Header{"Content-Type": []string{"application/json"}},
+			}, nil
+		}),
+	}
+	processor := newCardPayoutProcessor(
+		zap.NewNop(),
+		cfg,
+		staticClock{now: time.Date(2026, 3, 4, 1, 2, 3, 0, time.UTC)},
+		repo,
+		httpClient,
+		nil,
+	)
+
+	parentPaymentRef := "payment-parent-1"
+	op1 := parentPaymentRef + ":hop_4_card_payout_send"
+	op2 := parentPaymentRef + ":hop_4_card_payout_send_2"
+
+	req1 := validCardPayoutRequest()
+	req1.PayoutId = ""
+	req1.OperationRef = op1
+	req1.IdempotencyKey = "idem-1"
+	req1.ParentPaymentRef = parentPaymentRef
+	req1.CardPan = "2204310000002456"
+
+	req2 := validCardPayoutRequest()
+	req2.PayoutId = ""
+	req2.OperationRef = op2
+	req2.IdempotencyKey = "idem-2"
+	req2.ParentPaymentRef = parentPaymentRef
+	req2.CardPan = "2204320000009754"
+
+	if _, err := processor.Submit(context.Background(), req1); err != nil {
+		t.Fatalf("first submit failed: %v", err)
+	}
+	if _, err := processor.Submit(context.Background(), req2); err != nil {
+		t.Fatalf("second submit failed: %v", err)
+	}
+
+	first, err := repo.payouts.FindByOperationRef(context.Background(), op1)
+	if err != nil || first == nil {
+		t.Fatalf("expected first operation stored, err=%v", err)
+	}
+	second, err := repo.payouts.FindByOperationRef(context.Background(), op2)
+	if err != nil || second == nil {
+		t.Fatalf("expected second operation stored, err=%v", err)
+	}
+
+	if got, want := first.PaymentRef, parentPaymentRef; got != want {
+		t.Fatalf("first parent payment ref mismatch: got=%q want=%q", got, want)
+	}
+	if got, want := second.PaymentRef, parentPaymentRef; got != want {
+		t.Fatalf("second parent payment ref mismatch: got=%q want=%q", got, want)
+	}
+	if got, want := first.OperationRef, op1; got != want {
+		t.Fatalf("first operation ref mismatch: got=%q want=%q", got, want)
+	}
+	if got, want := second.OperationRef, op2; got != want {
+		t.Fatalf("second operation ref mismatch: got=%q want=%q", got, want)
+	}
+	if first.ProviderPaymentID == "" || second.ProviderPaymentID == "" {
+		t.Fatalf("expected provider payment ids for both operations")
+	}
+	if first.ProviderPaymentID == second.ProviderPaymentID {
+		t.Fatalf("expected different provider payment ids, got=%q", first.ProviderPaymentID)
+	}
+}
+
+func TestCardPayoutProcessor_ProcessCallback_UpdatesMatchingOperationWithinSameParent(t *testing.T) {
+	cfg := monetix.Config{
+		SecretKey:         "secret",
+		StatusSuccess:     "success",
+		StatusProcessing:  "processing",
+		AllowedCurrencies: []string{"RUB"},
+	}
+
+	parentPaymentRef := "payment-parent-1"
+	op1 := parentPaymentRef + ":hop_4_card_payout_send"
+	op2 := parentPaymentRef + ":hop_4_card_payout_send_2"
+	now := time.Date(2026, 3, 4, 2, 3, 4, 0, time.UTC)
+
+	repo := newMockRepository()
+	repo.payouts.Save(&model.CardPayout{
+		PaymentRef:   parentPaymentRef,
+		OperationRef: op1,
+		Status:       model.PayoutStatusWaiting,
+		CreatedAt:    now.Add(-time.Minute),
+		UpdatedAt:    now.Add(-time.Minute),
+	})
+	repo.payouts.Save(&model.CardPayout{
+		PaymentRef:   parentPaymentRef,
+		OperationRef: op2,
+		Status:       model.PayoutStatusWaiting,
+		CreatedAt:    now.Add(-time.Minute),
+		UpdatedAt:    now.Add(-time.Minute),
+	})
+
+	processor := newCardPayoutProcessor(
+		zap.NewNop(),
+		cfg,
+		staticClock{now: now},
+		repo,
+		&http.Client{},
+		nil,
+	)
+
+	cb := baseCallback()
+	cb.Payment.ID = op2
+	cb.Payment.Status = "success"
+	cb.Operation.Status = "success"
+	cb.Operation.Code = "0"
+	cb.Operation.Provider.PaymentID = "provider-op-2"
+	cb.Payment.Sum.Currency = "RUB"
+
+	sig, err := monetix.SignPayload(cb, cfg.SecretKey)
+	if err != nil {
+		t.Fatalf("failed to sign callback: %v", err)
+	}
+	cb.Signature = sig
+	payload, err := json.Marshal(cb)
+	if err != nil {
+		t.Fatalf("failed to marshal callback: %v", err)
+	}
+
+	status, err := processor.ProcessCallback(context.Background(), payload)
+	if err != nil {
+		t.Fatalf("expected no error, got %v", err)
+	}
+	if status != http.StatusOK {
+		t.Fatalf("expected status ok, got %d", status)
+	}
+
+	first, err := repo.payouts.FindByOperationRef(context.Background(), op1)
+	if err != nil || first == nil {
+		t.Fatalf("expected first operation present, err=%v", err)
+	}
+	second, err := repo.payouts.FindByOperationRef(context.Background(), op2)
+	if err != nil || second == nil {
+		t.Fatalf("expected second operation present, err=%v", err)
+	}
+
+	if got, want := first.Status, model.PayoutStatusWaiting; got != want {
+		t.Fatalf("first operation status mismatch: got=%v want=%v", got, want)
+	}
+	if got, want := second.Status, model.PayoutStatusSuccess; got != want {
+		t.Fatalf("second operation status mismatch: got=%v want=%v", got, want)
+	}
+	if got, want := second.PaymentRef, parentPaymentRef; got != want {
+		t.Fatalf("second parent payment ref mismatch: got=%q want=%q", got, want)
+	}
+}

api/gateway/mntx/internal/service/gateway/card_token_validation.go

@@ -16,6 +16,9 @@ func validateCardTokenPayoutRequest(req *mntxv1.CardTokenPayoutRequest, cfg mone
 	if err := validateOperationIdentity(strings.TrimSpace(req.GetPayoutId()), strings.TrimSpace(req.GetOperationRef())); err != nil {
 		return err
 	}
+	if strings.TrimSpace(req.GetParentPaymentRef()) == "" {
+		return newPayoutError("missing_parent_payment_ref", merrors.InvalidArgument("parent_payment_ref is required", "parent_payment_ref"))
+	}
 	if strings.TrimSpace(req.GetCustomerId()) == "" {
 		return newPayoutError("missing_customer_id", merrors.InvalidArgument("customer_id is required", "customer_id"))
 	}

api/gateway/mntx/internal/service/gateway/card_token_validation_test.go

@@ -28,6 +28,11 @@ func TestValidateCardTokenPayoutRequest_Errors(t *testing.T) {
 			mutate:   func(r *mntxv1.CardTokenPayoutRequest) { r.PayoutId = "" },
 			expected: "missing_operation_ref",
 		},
+		{
+			name:     "missing_parent_payment_ref",
+			mutate:   func(r *mntxv1.CardTokenPayoutRequest) { r.ParentPaymentRef = "" },
+			expected: "missing_parent_payment_ref",
+		},
 		{
 			name: "both_operation_and_payout_identity",
 			mutate: func(r *mntxv1.CardTokenPayoutRequest) {

api/gateway/mntx/internal/service/gateway/connector.go

@@ -69,18 +69,18 @@ func (s *Service) SubmitOperation(ctx context.Context, req *connectorv1.SubmitOp
 	if err != nil {
 		return &connectorv1.SubmitOperationResponse{Receipt: &connectorv1.OperationReceipt{Error: connectorError(connectorv1.ErrorCode_INVALID_PARAMS, err.Error(), op, "")}}, nil
 	}
+	parentPaymentRef := strings.TrimSpace(reader.String("parent_payment_ref"))
 
-	payoutID := strings.TrimSpace(reader.String("payout_id"))
+	payoutID := operationIDForRequest(operationRef)
-	payoutID = operationIDForRequest(payoutID, operationRef, idempotencyKey)
 
 	if strings.TrimSpace(reader.String("card_token")) != "" {
-		resp, err := s.CreateCardTokenPayout(ctx, buildCardTokenPayoutRequestFromParams(reader, payoutID, idempotencyKey, operationRef, intentRef, amountMinor, currency))
+		resp, err := s.CreateCardTokenPayout(ctx, buildCardTokenPayoutRequestFromParams(reader, payoutID, parentPaymentRef, idempotencyKey, operationRef, intentRef, amountMinor, currency))
 		if err != nil {
 			return &connectorv1.SubmitOperationResponse{Receipt: &connectorv1.OperationReceipt{Error: connectorError(mapErrorCode(err), err.Error(), op, "")}}, nil
 		}
 		return &connectorv1.SubmitOperationResponse{Receipt: payoutReceipt(resp.GetPayout())}, nil
 	}
-	cr := buildCardPayoutRequestFromParams(reader, payoutID, idempotencyKey, operationRef, intentRef, amountMinor, currency)
+	cr := buildCardPayoutRequestFromParams(reader, payoutID, parentPaymentRef, idempotencyKey, operationRef, intentRef, amountMinor, currency)
 	resp, err := s.CreateCardPayout(ctx, cr)
 	if err != nil {
 		return &connectorv1.SubmitOperationResponse{Receipt: &connectorv1.OperationReceipt{Error: connectorError(mapErrorCode(err), err.Error(), op, "")}}, nil
@@ -117,6 +117,7 @@ func mntxOperationParams() []*connectorv1.OperationParamSpec {
 			{Key: "card_holder", Type: connectorv1.ParamType_STRING, Required: false},
 			{Key: "amount_minor", Type: connectorv1.ParamType_INT, Required: false},
 			{Key: "project_id", Type: connectorv1.ParamType_INT, Required: false},
+			{Key: "parent_payment_ref", Type: connectorv1.ParamType_STRING, Required: true},
 			{Key: "customer_middle_name", Type: connectorv1.ParamType_STRING, Required: false},
 			{Key: "customer_country", Type: connectorv1.ParamType_STRING, Required: false},
 			{Key: "customer_state", Type: connectorv1.ParamType_STRING, Required: false},
@@ -167,24 +168,12 @@ func currencyFromOperation(op *connectorv1.Operation) string {
 	return strings.ToUpper(currency)
 }
 
-func operationIDForRequest(payoutID, operationRef, idempotencyKey string) string {
+func operationIDForRequest(operationRef string) string {
-	if ref := strings.TrimSpace(operationRef); ref != "" {
+	return strings.TrimSpace(operationRef)
-		return ref
-	}
-	if ref := strings.TrimSpace(payoutID); ref != "" {
-		return ref
-	}
-	return strings.TrimSpace(idempotencyKey)
 }
 
 func metadataFromReader(reader params.Reader) map[string]string {
 	metadata := reader.StringMap("metadata")
-	if metadata == nil {
-		metadata = map[string]string{}
-	}
-	if parentRef := strings.TrimSpace(reader.String("payout_id")); parentRef != "" && strings.TrimSpace(metadata[parentPaymentRefMetadataKey]) == "" {
-		metadata[parentPaymentRefMetadataKey] = parentRef
-	}
 	if len(metadata) == 0 {
 		return nil
 	}
@@ -192,7 +181,7 @@ func metadataFromReader(reader params.Reader) map[string]string {
 }
 
 func buildCardTokenPayoutRequestFromParams(reader params.Reader,
-	payoutID, idempotencyKey, operationRef, intentRef string,
+	payoutID, parentPaymentRef, idempotencyKey, operationRef, intentRef string,
 	amountMinor int64, currency string) *mntxv1.CardTokenPayoutRequest {
 	operationRef = strings.TrimSpace(operationRef)
 	payoutID = strings.TrimSpace(payoutID)
@@ -201,6 +190,7 @@ func buildCardTokenPayoutRequestFromParams(reader params.Reader,
 	}
 	req := &mntxv1.CardTokenPayoutRequest{
 		PayoutId:           payoutID,
+		ParentPaymentRef:   strings.TrimSpace(parentPaymentRef),
 		ProjectId:          readerInt64(reader, "project_id"),
 		CustomerId:         strings.TrimSpace(reader.String("customer_id")),
 		CustomerFirstName:  strings.TrimSpace(reader.String("customer_first_name")),
@@ -226,7 +216,7 @@ func buildCardTokenPayoutRequestFromParams(reader params.Reader,
 }
 
 func buildCardPayoutRequestFromParams(reader params.Reader,
-	payoutID, idempotencyKey, operationRef, intentRef string,
+	payoutID, parentPaymentRef, idempotencyKey, operationRef, intentRef string,
 	amountMinor int64, currency string) *mntxv1.CardPayoutRequest {
 	operationRef = strings.TrimSpace(operationRef)
 	payoutID = strings.TrimSpace(payoutID)
@@ -235,6 +225,7 @@ func buildCardPayoutRequestFromParams(reader params.Reader,
 	}
 	return &mntxv1.CardPayoutRequest{
 		PayoutId:           payoutID,
+		ParentPaymentRef:   strings.TrimSpace(parentPaymentRef),
 		ProjectId:          readerInt64(reader, "project_id"),
 		CustomerId:         strings.TrimSpace(reader.String("customer_id")),
 		CustomerFirstName:  strings.TrimSpace(reader.String("customer_first_name")),

api/gateway/mntx/internal/service/gateway/helpers.go

@@ -1,6 +1,7 @@
 package gateway
 
 import (
+	"strings"
 	"time"
 
 	"github.com/tech/sendico/gateway/mntx/storage/model"
@@ -22,7 +23,7 @@ func CardPayoutStateFromProto(clock clockpkg.Clock, p *mntxv1.CardPayoutState) *
 	}
 
 	return &model.CardPayout{
-		PaymentRef:        p.PayoutId,
+		PaymentRef:        strings.TrimSpace(p.GetParentPaymentRef()),
 		OperationRef:      p.GetOperationRef(),
 		IntentRef:         p.GetIntentRef(),
 		IdempotencyKey:    p.GetIdempotencyKey(),
@@ -42,6 +43,7 @@ func CardPayoutStateFromProto(clock clockpkg.Clock, p *mntxv1.CardPayoutState) *
 func StateToProto(m *model.CardPayout) *mntxv1.CardPayoutState {
 	return &mntxv1.CardPayoutState{
 		PayoutId:          firstNonEmpty(m.OperationRef, m.PaymentRef),
+		ParentPaymentRef:  m.PaymentRef,
 		ProjectId:         m.ProjectID,
 		CustomerId:        m.CustomerID,
 		AmountMinor:       m.AmountMinor,

api/gateway/mntx/internal/service/gateway/testhelpers_test.go

@@ -36,6 +36,7 @@ func testMonetixConfig() monetix.Config {
 func validCardPayoutRequest() *mntxv1.CardPayoutRequest {
 	return &mntxv1.CardPayoutRequest{
 		PayoutId:          "payout-1",
+		ParentPaymentRef:  "payment-parent-1",
 		CustomerId:        "cust-1",
 		CustomerFirstName: "Jane",
 		CustomerLastName:  "Doe",
@@ -52,6 +53,7 @@ func validCardPayoutRequest() *mntxv1.CardPayoutRequest {
 func validCardTokenPayoutRequest() *mntxv1.CardTokenPayoutRequest {
 	return &mntxv1.CardTokenPayoutRequest{
 		PayoutId:          "payout-1",
+		ParentPaymentRef:  "payment-parent-1",
 		CustomerId:        "cust-1",
 		CustomerFirstName: "Jane",
 		CustomerLastName:  "Doe",

api/payments/orchestrator/internal/service/orchestrator/card_payout_executor.go

@@ -85,6 +85,7 @@ func (e *gatewayCardPayoutExecutor) ExecuteCardPayout(ctx context.Context, req s
 	if token := strings.TrimSpace(card.Token); token != "" {
 		resp, createErr := client.CreateCardTokenPayout(ctx, &mntxv1.CardTokenPayoutRequest{
 			ProjectId:          projectID,
+			ParentPaymentRef:   strings.TrimSpace(req.Payment.PaymentRef),
 			CustomerId:         customer.id,
 			CustomerFirstName:  customer.firstName,
 			CustomerMiddleName: customer.middleName,
@@ -122,6 +123,7 @@ func (e *gatewayCardPayoutExecutor) ExecuteCardPayout(ctx context.Context, req s
 		}
 		resp, createErr := client.CreateCardPayout(ctx, &mntxv1.CardPayoutRequest{
 			ProjectId:          projectID,
+			ParentPaymentRef:   strings.TrimSpace(req.Payment.PaymentRef),
 			CustomerId:         customer.id,
 			CustomerFirstName:  customer.firstName,
 			CustomerMiddleName: customer.middleName,
@@ -538,9 +540,6 @@ func cardPayoutMetadata(payment *agg.Payment, step xplan.Step) map[string]string
 		out = map[string]string{}
 	}
 	if payment != nil {
-		if parentPaymentRef := strings.TrimSpace(payment.PaymentRef); parentPaymentRef != "" {
-			out[settlementMetadataParentPaymentRef] = parentPaymentRef
-		}
 		if quoteRef := firstNonEmpty(
 			strings.TrimSpace(payment.QuotationRef),
 			strings.TrimSpace(quoteRefFromSnapshot(payment.QuoteSnapshot)),

api/payments/orchestrator/internal/service/orchestrator/card_payout_executor_test.go

@@ -143,8 +143,8 @@ func TestGatewayCardPayoutExecutor_ExecuteCardPayout_SubmitsCardPayout(t *testin
 	if got, want := payoutReq.GetMetadata()[settlementMetadataOutgoingLeg], string(discovery.RailCardPayout); got != want {
 		t.Fatalf("outgoing_leg metadata mismatch: got=%q want=%q", got, want)
 	}
-	if got, want := payoutReq.GetMetadata()[settlementMetadataParentPaymentRef], "payment-1"; got != want {
+	if got, want := payoutReq.GetParentPaymentRef(), "payment-1"; got != want {
-		t.Fatalf("parent_payment_ref metadata mismatch: got=%q want=%q", got, want)
+		t.Fatalf("parent_payment_ref mismatch: got=%q want=%q", got, want)
 	}
 	if len(out.StepExecution.ExternalRefs) != 3 {
 		t.Fatalf("expected 3 external refs, got=%d", len(out.StepExecution.ExternalRefs))
@@ -275,8 +275,8 @@ func TestGatewayCardPayoutExecutor_ExecuteCardPayout_UsesStepMetadataOverrides(t
 	if got, want := payoutReq.GetMetadata()[batchmeta.MetaPayoutTargetRef], "recipient-2"; got != want {
 		t.Fatalf("target_ref metadata mismatch: got=%q want=%q", got, want)
 	}
-	if got, want := payoutReq.GetMetadata()[settlementMetadataParentPaymentRef], "payment-2"; got != want {
+	if got, want := payoutReq.GetParentPaymentRef(), "payment-2"; got != want {
-		t.Fatalf("parent_payment_ref metadata mismatch: got=%q want=%q", got, want)
+		t.Fatalf("parent_payment_ref mismatch: got=%q want=%q", got, want)
 	}
 }
 
@@ -319,3 +319,140 @@ func TestGatewayCardPayoutExecutor_ExecuteCardPayout_RequiresGatewayRegistry(t *
 		t.Fatalf("unexpected error: %v", err)
 	}
 }
+
+func TestGatewayCardPayoutExecutor_ExecuteCardPayout_BatchChildrenUseDistinctOperationRefsAndSharedParent(t *testing.T) {
+	orgID := bson.NewObjectID()
+
+	var payoutReqs []*mntxv1.CardPayoutRequest
+	executor := &gatewayCardPayoutExecutor{
+		gatewayRegistry: &fakeGatewayRegistry{
+			items: []*model.GatewayInstanceDescriptor{
+				{
+					ID:         paymenttypes.DefaultCardsGatewayID,
+					InstanceID: paymenttypes.DefaultCardsGatewayID,
+					Rail:       discovery.RailCardPayout,
+					InvokeURI:  "grpc://mntx-gateway:50051",
+					IsEnabled:  true,
+				},
+			},
+		},
+		dialClient: func(_ context.Context, _ string) (mntxclient.Client, error) {
+			return &mntxclient.Fake{
+				CreateCardPayoutFn: func(_ context.Context, req *mntxv1.CardPayoutRequest) (*mntxv1.CardPayoutResponse, error) {
+					payoutReqs = append(payoutReqs, req)
+					return &mntxv1.CardPayoutResponse{
+						Payout: &mntxv1.CardPayoutState{
+							PayoutId:     req.GetOperationRef(),
+							OperationRef: req.GetOperationRef(),
+						},
+					}, nil
+				},
+			}, nil
+		},
+	}
+
+	payment := &agg.Payment{
+		OrganizationBoundBase: pm.OrganizationBoundBase{OrganizationRef: orgID},
+		PaymentRef:            "payment-3",
+		IdempotencyKey:        "idem-3",
+		QuotationRef:          "quote-3",
+		IntentSnapshot: model.PaymentIntent{
+			Ref: "intent-3",
+			Destination: model.PaymentEndpoint{
+				Type: model.EndpointTypeCard,
+				Card: &model.CardEndpoint{
+					Pan:      "2200700142860161",
+					ExpMonth: 3,
+					ExpYear:  2030,
+				},
+			},
+			Customer: &model.Customer{
+				ID:        "cust-3",
+				FirstName: "Stephan",
+				LastName:  "Deshevikh",
+				IP:        "198.51.100.10",
+			},
+			Amount: &paymenttypes.Money{
+				Amount:   "1.000000",
+				Currency: "USDT",
+			},
+		},
+		QuoteSnapshot: &model.PaymentQuoteSnapshot{
+			ExpectedSettlementAmount: &paymenttypes.Money{
+				Amount:   "76.50",
+				Currency: "RUB",
+			},
+			QuoteRef: "quote-3",
+		},
+	}
+
+	firstReq := sexec.StepRequest{
+		Payment: payment,
+		Step: xplan.Step{
+			StepRef:    "hop_4_card_payout_send",
+			StepCode:   "hop.4.card_payout.send",
+			Action:     discovery.RailOperationSend,
+			Rail:       discovery.RailCardPayout,
+			Gateway:    paymenttypes.DefaultCardsGatewayID,
+			InstanceID: paymenttypes.DefaultCardsGatewayID,
+		},
+		StepExecution: agg.StepExecution{
+			StepRef:  "hop_4_card_payout_send",
+			StepCode: "hop.4.card_payout.send",
+			Attempt:  1,
+		},
+	}
+	secondReq := sexec.StepRequest{
+		Payment: payment,
+		Step: xplan.Step{
+			StepRef:    "hop_4_card_payout_send_2",
+			StepCode:   "hop.4.card_payout.send",
+			Action:     discovery.RailOperationSend,
+			Rail:       discovery.RailCardPayout,
+			Gateway:    paymenttypes.DefaultCardsGatewayID,
+			InstanceID: paymenttypes.DefaultCardsGatewayID,
+			Metadata: map[string]string{
+				batchmeta.MetaPayoutTargetRef: "recipient-2",
+				batchmeta.MetaAmount:          "150",
+				batchmeta.MetaCurrency:        "RUB",
+				batchmeta.MetaCardPan:         "2200700142860162",
+				batchmeta.MetaCardExpMonth:    "4",
+				batchmeta.MetaCardExpYear:     "2030",
+			},
+		},
+		StepExecution: agg.StepExecution{
+			StepRef:  "hop_4_card_payout_send_2",
+			StepCode: "hop.4.card_payout.send",
+			Attempt:  1,
+		},
+	}
+
+	if _, err := executor.ExecuteCardPayout(context.Background(), firstReq); err != nil {
+		t.Fatalf("first ExecuteCardPayout returned error: %v", err)
+	}
+	if _, err := executor.ExecuteCardPayout(context.Background(), secondReq); err != nil {
+		t.Fatalf("second ExecuteCardPayout returned error: %v", err)
+	}
+
+	if got, want := len(payoutReqs), 2; got != want {
+		t.Fatalf("submitted request count mismatch: got=%d want=%d", got, want)
+	}
+	if got, want := payoutReqs[0].GetOperationRef(), "payment-3:hop_4_card_payout_send"; got != want {
+		t.Fatalf("first operation_ref mismatch: got=%q want=%q", got, want)
+	}
+	if got, want := payoutReqs[1].GetOperationRef(), "payment-3:hop_4_card_payout_send_2"; got != want {
+		t.Fatalf("second operation_ref mismatch: got=%q want=%q", got, want)
+	}
+	if payoutReqs[0].GetPayoutId() != "" || payoutReqs[1].GetPayoutId() != "" {
+		t.Fatalf("expected empty payout_id for both child operations")
+	}
+	if got, want := payoutReqs[0].GetParentPaymentRef(), "payment-3"; got != want {
+		t.Fatalf("first parent_payment_ref mismatch: got=%q want=%q", got, want)
+	}
+	if got, want := payoutReqs[1].GetParentPaymentRef(), "payment-3"; got != want {
+		t.Fatalf("second parent_payment_ref mismatch: got=%q want=%q", got, want)
+	}
+	if payoutReqs[0].GetCardPan() == payoutReqs[1].GetCardPan() {
+		t.Fatalf("expected different destination cards across child operations")
+	}
+}

api/payments/orchestrator/internal/service/orchestrator/settlement_executor.go

@@ -15,9 +15,8 @@ import (
 )
 
 const (
-	settlementMetadataQuoteRef         = "quote_ref"
+	settlementMetadataQuoteRef    = "quote_ref"
-	settlementMetadataOutgoingLeg      = "outgoing_leg"
+	settlementMetadataOutgoingLeg = "outgoing_leg"
-	settlementMetadataParentPaymentRef = "parent_payment_ref"
 )
 
 type gatewayProviderSettlementExecutor struct {

api/proto/gateway/mntx/v1/mntx.proto

@@ -21,7 +21,7 @@ enum PayoutStatus {
 
 // Request to initiate a Monetix card payout.
 message CardPayoutRequest {
-  string payout_id = 1; // internal payout id, mapped to Monetix payment_id
+  string payout_id = 1; // alternate operation id mapped to Monetix payment_id
   int64 project_id = 2; // optional override; defaults to configured project id
   string customer_id = 3;
   string customer_first_name = 4;
@@ -40,9 +40,10 @@ message CardPayoutRequest {
   uint32 card_exp_month = 17;
   string card_holder = 18;
   map<string, string> metadata = 30;
-  string operation_ref = 31;
+  string operation_ref = 31; // preferred operation id mapped to Monetix payment_id
   string idempotency_key = 32;
   string intent_ref = 33;
+  string parent_payment_ref = 34;
 }
 
 // Persisted payout state for retrieval and status updates.
@@ -61,6 +62,7 @@ message CardPayoutState {
   string operation_ref = 12;
   string idempotency_key = 13;
   string intent_ref = 14;
+  string parent_payment_ref = 15;
 }
 
 // Response returned immediately after submitting a payout to Monetix.
@@ -97,7 +99,7 @@ message ListGatewayInstancesResponse {
 
 // Request to initiate a token-based card payout.
 message CardTokenPayoutRequest {
-  string payout_id = 1;
+  string payout_id = 1; // alternate operation id
   int64 project_id = 2;
   string customer_id = 3;
 
@@ -119,9 +121,10 @@ message CardTokenPayoutRequest {
   string card_holder = 16;
   string masked_pan = 17;
   map<string, string> metadata = 30;
-  string operation_ref = 31;
+  string operation_ref = 31; // preferred operation id
   string idempotency_key = 32;
   string intent_ref = 33;
+  string parent_payment_ref = 34;
 }
 
 // Response returned immediately after submitting a token payout to Monetix.

frontend/pshared/lib/provider/payment/quotation/intent_builder.dart

@@ -24,6 +24,7 @@ import 'package:pshared/provider/payment/flow.dart';
 import 'package:pshared/provider/recipient/provider.dart';
 import 'package:pshared/utils/payment/fx_helpers.dart';
 
+
 class QuotationIntentBuilder {
   static const String _settlementCurrency = 'RUB';
 

frontend/pshared/lib/provider/payment/quotation/quotation.dart

@@ -26,6 +26,7 @@ import 'package:pshared/service/payment/quotation.dart';
 import 'package:pshared/utils/payment/quote_helpers.dart';
 import 'package:pshared/utils/exception.dart';
 
+
 class QuotationProvider extends ChangeNotifier {
   static final _logger = Logger('provider.payment.quotation');
   Resource<PaymentQuote> _quotation = Resource(