.claude/CLAUDE.md

@@ -247,6 +247,12 @@ The native Android app is a Capacitor 8 wrapper of the `ui` SPA, scaffolded unde
     order, and its `test` flag must match the shop's `IsTest` (a test-shop payment must never credit
     real chips). Answer 200 for anything durably decided, 5xx only to be redelivered (YooKassa retries
     24h).
+  - **Subscribe to `refund.succeeded`, not just the payment events.** The YooKassa cabinet lets an
+    operator refund without touching our API, so without that event the money goes back while the
+    chips stay credited. The reversal engine is **full-refund-only** (it rejects any amount other than
+    the order's), so a partial refund must record nothing and be logged for a human — there is no
+    non-arbitrary chip cost for a part-refund. Also: a refund is only recorded in status `succeeded`;
+    a `pending` one can still be canceled and the ledger is append-only.
   - **YooKassa DOES have a test mode** — a separate *test shop* (own shopId/secret, test cards, up to
     20 of them), and webhooks/receipts/refunds all work there. The whole rail is verifiable on the
     contour without real money; don't plan around "no test payments".

PLAN.md

@@ -1038,8 +1038,11 @@ when no YooKassa shop is configured, so reviving it is a credentials change (D47
   records a `failed` event. 200 = durably decided, 5xx = redeliver.
 - **Reconcile** — `runOrderReaper` asks the provider about each pending order that reached its expiry
   age carrying a payment id, and credits the ones really paid (D49). One request per order.
-- **Refund** — the `/_gm` button calls `POST /v3/refunds` first and records only on success, under the
-  provider's own refund id (D50); a failure records nothing.
+- **Refund** — the `/_gm` button calls `POST /v3/refunds` first and records only on a **succeeded**
+  refund, under the provider's own refund id (D50); a failure — or a still-`pending` refund — records
+  nothing, and pressing again is safe. `refund.succeeded` is handled too (D52), because the merchant
+  cabinet can issue a refund that never passes through our API; a **partial** refund records nothing
+  and is logged for an operator (the engine is full-refund-only).
 - **Fiscalization** — «Чеки от ЮKassa» with the `receipt` sent from code (D51), reversing E10's B4:
   YooKassa has no cabinet-side generic receipt. `BACKEND_YOOKASSA_VAT_CODE` is a deploy variable;
   the settlement subject/method are constants.
@@ -1052,7 +1055,9 @@ when no YooKassa shop is configured, so reviving it is a credentials change (D47
   forged notification credits nothing, a foreign sender is refused, a live payment on a test shop is
   refused, a decline records `failed`, the reconcile sweep credits a lost notification and leaves an
   unpaid order alone, the refund moves money then records — and records nothing when it fails, the
-  order path mints a payment with a receipt, and D36 still gates the rail).
+  order path mints a payment with a receipt, D36 still gates the rail, a cabinet refund is reversed
+  once, the event after a console refund is a no-op, a partial refund changes nothing, an unconfirmed
+  refund reverses nothing, and a pending refund records nothing until it settles).
 
 **Contour-safe:** no migration, no wire change; the client is rail-agnostic (only the mock URL and an
 e2e assertion name a provider).

backend/internal/inttest/payments_yookassa_test.go

@@ -37,8 +37,12 @@ type fakeYooKassa struct {
 	payments map[string]yookassa.Payment
 	// refundFails makes POST /refunds answer 500, standing in for a provider that did not move money.
 	refundFails bool
+	// refundStatus is the status a created refund reports; empty means succeeded.
+	refundStatus string
 	// refundCalls counts the refunds actually requested.
 	refundCalls int
+	// refunds answers GET /refunds/{id}; a missing id is a 404.
+	refunds map[string]yookassa.Refund
 	// createdIdempotenceKey records the key sent on the last create-payment call.
 	createdIdempotenceKey string
 	// lastReceipt records the receipt object of the last create-payment call.
@@ -48,7 +52,7 @@ type fakeYooKassa struct {
 // newFakeYooKassa starts the fake API and returns it with a shop config pointed at it.
 func newFakeYooKassa(t *testing.T) (*fakeYooKassa, yookassa.Config) {
 	t.Helper()
-	f := &fakeYooKassa{payments: map[string]yookassa.Payment{}}
+	f := &fakeYooKassa{payments: map[string]yookassa.Payment{}, refunds: map[string]yookassa.Refund{}}
 	srv := httptest.NewServer(http.HandlerFunc(f.serve))
 	t.Cleanup(srv.Close)
 	return f, yookassa.Config{ShopID: ykShopID, SecretKey: ykSecretKey, IsTest: true, BaseURL: srv.URL}
@@ -94,14 +98,37 @@ func (f *fakeYooKassa) serve(w http.ResponseWriter, r *http.Request) {
 		f.refundCalls++
 		var body yookassa.RefundRequest
 		_ = json.NewDecoder(r.Body).Decode(&body)
-		_ = json.NewEncoder(w).Encode(yookassa.Refund{
-			ID: "refund-1", Status: yookassa.StatusSucceeded, PaymentID: body.PaymentID, Amount: body.Amount,
-		})
+		status := f.refundStatus
+		if status == "" {
+			status = yookassa.StatusSucceeded
+		}
+		// The ledger dedupes refunds on (provider, refund id) across the whole database, so the id has
+		// to be unique per payment or one test's refund looks like another's duplicate.
+		refund := yookassa.Refund{ID: "refund-" + body.PaymentID, Status: status, PaymentID: body.PaymentID, Amount: body.Amount}
+		f.refunds[refund.ID] = refund
+		_ = json.NewEncoder(w).Encode(refund)
+	case r.Method == http.MethodGet && strings.HasPrefix(r.URL.Path, "/refunds/"):
+		refund, ok := f.refunds[strings.TrimPrefix(r.URL.Path, "/refunds/")]
+		if !ok {
+			w.WriteHeader(http.StatusNotFound)
+			_, _ = w.Write([]byte(`{"type":"error","description":"not found"}`))
+			return
+		}
+		_ = json.NewEncoder(w).Encode(refund)
 	default:
 		w.WriteHeader(http.StatusNotFound)
 	}
 }
 
+// setRefund publishes a refund the API will report — how a test stands up a refund that was issued
+// somewhere other than through our own API, such as in the merchant cabinet.
+func (f *fakeYooKassa) setRefund(id string, refund yookassa.Refund) {
+	f.mu.Lock()
+	defer f.mu.Unlock()
+	refund.ID = id
+	f.refunds[id] = refund
+}
+
 // setPayment overwrites what the API reports for a payment — how a test says "the money did (or did
 // not) really move", independently of what a notification claims.
 func (f *fakeYooKassa) setPayment(id string, mutate func(p *yookassa.Payment)) {
@@ -383,8 +410,8 @@ func TestYooKassaConsoleRefundMovesMoneyThenRecords(t *testing.T) {
 		acc).Scan(&provider, &refundID); err != nil {
 		t.Fatalf("read refund ledger row: %v", err)
 	}
-	if provider != "yookassa" || refundID != "refund-1" {
-		t.Errorf("refund ledger row = (%s, %s), want (yookassa, refund-1)", provider, refundID)
+	if provider != "yookassa" || refundID != "refund-"+paymentID {
+		t.Errorf("refund ledger row = (%s, %s), want (yookassa, refund-%s)", provider, refundID, paymentID)
 	}
 }
 
@@ -502,3 +529,182 @@ func TestYooKassaOrderRequiresAnEmailAnchor(t *testing.T) {
 		t.Fatalf("order = %d (%s), want 403 email_required", rec.Code, rec.Body.String())
 	}
 }
+
+// postYooKassaRefundNotify posts a refund notification to the intake and reports the status code.
+func postYooKassaRefundNotify(t *testing.T, srv *server.Server, refundID, paymentID string) int {
+	t.Helper()
+	body := fmt.Sprintf(`{"type":"notification","event":%q,"object":{"id":%q,"status":"succeeded","payment_id":%q}}`,
+		yookassa.EventRefundSucceeded, refundID, paymentID)
+	req := httptest.NewRequest(http.MethodPost, "/api/v1/internal/payments/yookassa/notify", strings.NewReader(body))
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("X-Forwarded-For", ykSenderIP)
+	rec := httptest.NewRecorder()
+	srv.Handler().ServeHTTP(rec, req)
+	return rec.Code
+}
+
+// fundedYooKassaOrder seeds an order and credits it, leaving an account with chips to reverse.
+func fundedYooKassaOrder(t *testing.T, f *fakeYooKassa, srv *server.Server, pay *payments.Service, acc uuid.UUID) (uuid.UUID, string) {
+	t.Helper()
+	orderID, paymentID := seedYooKassaOrder(t, f, pay, acc)
+	if code := postYooKassaNotify(t, srv, ykSenderIP, yookassa.EventPaymentSucceeded, paymentID, orderID.String()); code != http.StatusOK {
+		t.Fatalf("notify = %d, want 200", code)
+	}
+	return orderID, paymentID
+}
+
+// TestYooKassaCabinetRefundIsReversed is why the refund event is handled at all: an operator can
+// refund in the merchant cabinet, which never passes through our API, so without this the money would
+// go back while the chips stayed credited.
+func TestYooKassaCabinetRefundIsReversed(t *testing.T) {
+	f, shop := newFakeYooKassa(t)
+	srv, pay := yookassaServer(t, shop)
+	acc := provisionAccount(t)
+	_, paymentID := fundedYooKassaOrder(t, f, srv, pay, acc)
+	if got := readBalance(t, acc, "direct"); got != 100 {
+		t.Fatalf("balance before the refund = %d, want 100", got)
+	}
+
+	// The refund exists at the provider, issued outside our API.
+	f.setRefund("cabinet-refund-1", yookassa.Refund{
+		Status: yookassa.StatusSucceeded, PaymentID: paymentID,
+		Amount: yookassa.Amount{Value: "149.00", Currency: "RUB"},
+	})
+	if code := postYooKassaRefundNotify(t, srv, "cabinet-refund-1", paymentID); code != http.StatusOK {
+		t.Fatalf("refund notify = %d, want 200", code)
+	}
+	if got := readBalance(t, acc, "direct"); got != 0 {
+		t.Errorf("balance = %d, want 0 — a cabinet refund did not revoke the chips", got)
+	}
+	if f.refundCalls != 0 {
+		t.Errorf("provider refunds requested = %d, want 0 — the money had already moved", f.refundCalls)
+	}
+	var provider, refundID string
+	if err := testDB.QueryRowContext(context.Background(),
+		`SELECT provider, provider_payment_id FROM payments.ledger WHERE account_id=$1 AND kind='refund'`,
+		acc).Scan(&provider, &refundID); err != nil {
+		t.Fatalf("read refund ledger row: %v", err)
+	}
+	if provider != "yookassa" || refundID != "cabinet-refund-1" {
+		t.Errorf("refund ledger row = (%s, %s), want (yookassa, cabinet-refund-1)", provider, refundID)
+	}
+
+	// A redelivery reverses nothing a second time.
+	if code := postYooKassaRefundNotify(t, srv, "cabinet-refund-1", paymentID); code != http.StatusOK {
+		t.Fatalf("redelivered refund notify = %d, want 200", code)
+	}
+	if ledgerRows(t, acc, "refund") != 1 {
+		t.Errorf("refund ledger rows = %d, want 1", ledgerRows(t, acc, "refund"))
+	}
+}
+
+// TestYooKassaRefundNotifyAfterConsoleRefundIsANoOp checks the two refund entry points cannot double
+// up: the event for a refund the console already recorded reverses nothing again.
+func TestYooKassaRefundNotifyAfterConsoleRefundIsANoOp(t *testing.T) {
+	f, shop := newFakeYooKassa(t)
+	srv, pay := yookassaServer(t, shop)
+	acc := provisionAccount(t)
+	orderID, paymentID := fundedYooKassaOrder(t, f, srv, pay, acc)
+
+	base := "http://admin.test/_gm/users/" + acc.String()
+	if code, _ := consoleDo(srv.Handler(), http.MethodPost, base+"/refund", "order_id="+orderID.String(), "http://admin.test"); code != http.StatusOK {
+		t.Fatalf("console refund = %d, want 200", code)
+	}
+	if got := readBalance(t, acc, "direct"); got != 0 {
+		t.Fatalf("balance after the console refund = %d, want 0", got)
+	}
+	// YooKassa then notifies about that same refund.
+	if code := postYooKassaRefundNotify(t, srv, "refund-"+paymentID, paymentID); code != http.StatusOK {
+		t.Fatalf("refund notify = %d, want 200", code)
+	}
+	if ledgerRows(t, acc, "refund") != 1 {
+		t.Errorf("refund ledger rows = %d, want 1 (reversed once)", ledgerRows(t, acc, "refund"))
+	}
+	if abuse, loss := readRisk(t, acc); abuse || loss != 0 {
+		t.Errorf("risk = (abuse %v, loss %d), want none — the second reversal ran anyway", abuse, loss)
+	}
+}
+
+// TestYooKassaPartialRefundIsLeftToAnOperator: the reversal engine revokes exactly what the pack
+// funded and rejects any other amount, so a partial refund cannot be recorded without guessing how
+// many chips it costs. It must change nothing rather than guess.
+func TestYooKassaPartialRefundIsLeftToAnOperator(t *testing.T) {
+	f, shop := newFakeYooKassa(t)
+	srv, pay := yookassaServer(t, shop)
+	acc := provisionAccount(t)
+	_, paymentID := fundedYooKassaOrder(t, f, srv, pay, acc)
+
+	f.setRefund("partial-1", yookassa.Refund{
+		Status: yookassa.StatusSucceeded, PaymentID: paymentID,
+		Amount: yookassa.Amount{Value: "50.00", Currency: "RUB"}, // part of the 149.00 order
+	})
+	if code := postYooKassaRefundNotify(t, srv, "partial-1", paymentID); code != http.StatusOK {
+		t.Fatalf("refund notify = %d, want 200", code)
+	}
+	if got := readBalance(t, acc, "direct"); got != 100 {
+		t.Errorf("balance = %d, want 100 — a partial refund revoked chips", got)
+	}
+	if ledgerRows(t, acc, "refund") != 0 {
+		t.Error("a partial refund wrote a refund ledger row")
+	}
+}
+
+// TestYooKassaRefundNotifyIsNotEvidence: as with a payment, the body only names a refund. One the
+// provider does not confirm reverses nothing.
+func TestYooKassaRefundNotifyIsNotEvidence(t *testing.T) {
+	f, shop := newFakeYooKassa(t)
+	srv, pay := yookassaServer(t, shop)
+	acc := provisionAccount(t)
+	_, paymentID := fundedYooKassaOrder(t, f, srv, pay, acc)
+
+	// A refund the provider has never heard of.
+	if code := postYooKassaRefundNotify(t, srv, "invented-refund", paymentID); code != http.StatusOK {
+		t.Fatalf("refund notify = %d, want 200", code)
+	}
+	// One that exists but is not final.
+	f.setRefund("pending-refund", yookassa.Refund{
+		Status: yookassa.StatusPending, PaymentID: paymentID,
+		Amount: yookassa.Amount{Value: "149.00", Currency: "RUB"},
+	})
+	if code := postYooKassaRefundNotify(t, srv, "pending-refund", paymentID); code != http.StatusOK {
+		t.Fatalf("refund notify = %d, want 200", code)
+	}
+	if got := readBalance(t, acc, "direct"); got != 100 {
+		t.Errorf("balance = %d, want 100 — an unconfirmed refund revoked chips", got)
+	}
+	if ledgerRows(t, acc, "refund") != 0 {
+		t.Error("an unconfirmed refund wrote a refund ledger row")
+	}
+}
+
+// TestYooKassaPendingRefundRecordsNothing: a refund can still be canceled while pending and the
+// ledger is append-only, so the console records only a completed one. Retrying is the way out.
+func TestYooKassaPendingRefundRecordsNothing(t *testing.T) {
+	f, shop := newFakeYooKassa(t)
+	srv, pay := yookassaServer(t, shop)
+	acc := provisionAccount(t)
+	orderID, _ := fundedYooKassaOrder(t, f, srv, pay, acc)
+
+	f.refundStatus = yookassa.StatusPending
+	base := "http://admin.test/_gm/users/" + acc.String()
+	_, body := consoleDo(srv.Handler(), http.MethodPost, base+"/refund", "order_id="+orderID.String(), "http://admin.test")
+	if !strings.Contains(body, "not completed the refund yet") || !strings.Contains(body, "nothing was recorded") {
+		t.Errorf("message = %q, want it to say the refund is not final and nothing was recorded", body)
+	}
+	if got := readBalance(t, acc, "direct"); got != 100 {
+		t.Errorf("balance = %d, want 100 — chips were revoked for an unsettled refund", got)
+	}
+	if ledgerRows(t, acc, "refund") != 0 {
+		t.Error("a pending refund wrote a refund ledger row")
+	}
+
+	// Once the provider settles it, pressing again records the reversal — the idempotency key returns
+	// the same refund rather than paying twice.
+	f.refundStatus = yookassa.StatusSucceeded
+	if code, body := consoleDo(srv.Handler(), http.MethodPost, base+"/refund", "order_id="+orderID.String(), "http://admin.test"); code != http.StatusOK || !strings.Contains(body, "revoked 100 chips") {
+		t.Fatalf("retried refund = %d, body has 'revoked 100 chips' = %v", code, strings.Contains(body, "revoked 100 chips"))
+	}
+	if got := readBalance(t, acc, "direct"); got != 0 {
+		t.Errorf("balance = %d, want 0", got)
+	}
+}

backend/internal/payments/service_intake.go

@@ -113,6 +113,16 @@ func (s *Service) OrderProviderRef(ctx context.Context, orderID uuid.UUID) (Orde
 	return orderRef(o)
 }
 
+// OrderByProviderPayment reads the order a provider's payment id belongs to. It resolves a provider
+// event that names only its own payment — such as a refund notification — back to an order.
+func (s *Service) OrderByProviderPayment(ctx context.Context, provider, providerPaymentID string) (OrderRef, error) {
+	o, err := s.store.orderByProviderPayment(ctx, provider, providerPaymentID)
+	if err != nil {
+		return OrderRef{}, err
+	}
+	return orderRef(o)
+}
+
 // reconcileBatch bounds one reconcile sweep, so a backlog cannot turn a periodic tick into a long
 // run of provider calls.
 const reconcileBatch = 50

backend/internal/payments/store_intake.go

@@ -229,6 +229,29 @@ func derefString(p *string) string {
 	return *p
 }
 
+// orderByProviderPayment reads the order a provider's payment id belongs to, or ErrOrderNotFound.
+// It is how a provider event that names only its own payment — a refund notification, say — is
+// resolved back to an order.
+func (s *Store) orderByProviderPayment(ctx context.Context, provider, providerPaymentID string) (orderRow, error) {
+	if provider == "" || providerPaymentID == "" {
+		return orderRow{}, ErrOrderNotFound
+	}
+	var o model.Orders
+	err := postgres.SELECT(table.Orders.AllColumns).
+		FROM(table.Orders).
+		WHERE(table.Orders.Provider.EQ(postgres.String(provider)).
+			AND(table.Orders.ProviderPaymentID.EQ(postgres.String(providerPaymentID)))).
+		LIMIT(1).
+		QueryContext(ctx, s.db, &o)
+	if errors.Is(err, qrm.ErrNoRows) {
+		return orderRow{}, ErrOrderNotFound
+	}
+	if err != nil {
+		return orderRow{}, fmt.Errorf("payments: load order by %s payment %s: %w", provider, providerPaymentID, err)
+	}
+	return newOrderRow(o), nil
+}
+
 // attachProviderPayment records the provider's own payment id on a pending order, as soon as the
 // provider mints it. It is what later lets an unattended order be re-checked against the provider
 // and a refund address the right payment; fund overwrites it with the same value when the callback

backend/internal/server/handlers_admin_refund.go

@@ -3,6 +3,7 @@ package server
 import (
 	"context"
 	"encoding/csv"
+	"errors"
 	"fmt"
 	"strconv"
 	"strings"
@@ -71,6 +72,12 @@ func (s *Server) refundOrder(ctx context.Context, ref payments.OrderRef) (paymen
 		return s.payments.RefundOrderFull(ctx, ref.OrderID)
 	}
 	refundID, err := s.refundYooKassa(ctx, ref)
+	if errors.Is(err, errRefundNotFinal) {
+		// The money is on its way but not settled. Nothing is recorded yet; pressing again is safe —
+		// the idempotency key returns the same refund rather than paying a second time.
+		s.log.Warn("yookassa refund not final", zap.String("order", ref.OrderID.String()), zap.Error(err))
+		return payments.RefundOutcome{}, fmt.Errorf("%w — nothing was recorded; try again in a minute", err)
+	}
 	if err != nil {
 		s.log.Error("yookassa refund failed", zap.String("order", ref.OrderID.String()), zap.Error(err))
 		return payments.RefundOutcome{}, fmt.Errorf("the provider did not refund the payment, nothing was recorded: %w", err)

backend/internal/server/handlers_yookassa.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"encoding/json"
 	"errors"
+	"fmt"
 	"io"
 	"net/http"
 	"strings"
@@ -111,9 +112,11 @@ func (s *Server) handleYooKassaNotify(c *gin.Context) {
 	}
 	switch note.Event {
 	case yookassa.EventPaymentSucceeded, yookassa.EventPaymentCanceled:
+	case yookassa.EventRefundSucceeded:
+		s.handleYooKassaRefundNotification(c, note)
+		return
 	default:
-		// Refund events are informational: refunds are issued through the API, which records them
-		// synchronously. Anything else is a subscription we do not act on.
+		// A subscription we do not act on.
 		c.String(http.StatusOK, "ignored")
 		return
 	}
@@ -189,6 +192,95 @@ func (s *Server) handleYooKassaNotify(c *gin.Context) {
 	c.String(http.StatusOK, "ok")
 }
 
+// handleYooKassaRefundNotification reverses a refund the provider reports as completed. Its reason
+// for existing is the merchant cabinet: an operator can refund there, and such a refund never passes
+// through our API, so without this the money would go back while the chips stayed credited.
+//
+// As with a payment, the body is only a hint — the refund is re-read from the API before anything is
+// recorded. The reversal is idempotent on (yookassa, refund id), so the notification for a refund the
+// console already recorded reverses nothing a second time.
+func (s *Server) handleYooKassaRefundNotification(c *gin.Context, note yookassa.Notification) {
+	claimed, err := note.Refund()
+	if err != nil {
+		s.log.Warn("yookassa notify: unusable refund object", zap.Error(err))
+		c.String(http.StatusOK, "ignored")
+		return
+	}
+	ctx := c.Request.Context()
+	// The refund object names the payment, not our order, so the order is found by the payment id we
+	// recorded when the payment was minted. The claim is untrusted, but it only selects which shop's
+	// credentials perform the confirming read; the confirmed refund is then bound back to this order.
+	ref, err := s.payments.OrderByProviderPayment(ctx, providerYooKassa, claimed.PaymentID)
+	if errors.Is(err, payments.ErrOrderNotFound) {
+		s.log.Warn("yookassa refund notify: no order for the payment",
+			zap.String("payment", claimed.PaymentID), zap.String("refund", claimed.ID))
+		c.String(http.StatusOK, "ignored")
+		return
+	}
+	if err != nil {
+		s.log.Error("yookassa refund notify: order lookup failed", zap.String("payment", claimed.PaymentID), zap.Error(err))
+		c.String(http.StatusInternalServerError, "error")
+		return
+	}
+	shop, ok := s.yookassa.Shop(ref.Shop)
+	if !ok {
+		s.log.Warn("yookassa refund notify: no shop for the order's channel", zap.String("order", ref.OrderID.String()))
+		c.String(http.StatusOK, "ignored")
+		return
+	}
+	refund, err := shop.GetRefund(ctx, claimed.ID)
+	if err != nil {
+		var apiErr *yookassa.APIError
+		if errors.As(err, &apiErr) && !apiErr.Retryable() {
+			s.log.Warn("yookassa refund notify: refund not confirmed",
+				zap.String("order", ref.OrderID.String()), zap.String("refund", claimed.ID), zap.Error(err))
+			c.String(http.StatusOK, "ignored")
+			return
+		}
+		s.log.Error("yookassa refund notify: confirm failed",
+			zap.String("order", ref.OrderID.String()), zap.String("refund", claimed.ID), zap.Error(err))
+		c.String(http.StatusInternalServerError, "error")
+		return
+	}
+	if refund.Status != yookassa.StatusSucceeded || refund.PaymentID != ref.PaymentID {
+		s.log.Warn("yookassa refund notify: confirmed refund does not settle this order",
+			zap.String("order", ref.OrderID.String()), zap.String("refund", refund.ID),
+			zap.String("status", refund.Status), zap.String("refund_payment", refund.PaymentID))
+		c.String(http.StatusOK, "ignored")
+		return
+	}
+	// The reversal engine is full-refund-only by design: it revokes exactly what the pack funded and
+	// rejects any other amount. A partial refund therefore cannot be recorded without guessing how
+	// many chips it should cost, so it is left to an operator — loudly, because the money has moved.
+	paid, err := payments.ParseMoney(refund.Amount.Value, payments.Currency(refund.Amount.Currency))
+	if err != nil || paid.Currency() != ref.Amount.Currency() || paid.Minor() != ref.Amount.Minor() {
+		s.log.Error("yookassa refund notify: partial refund needs an operator; nothing was reversed",
+			zap.String("order", ref.OrderID.String()), zap.String("refund", refund.ID),
+			zap.String("refunded", refund.Amount.Value), zap.String("order_amount", ref.Amount.Major()))
+		c.String(http.StatusOK, "ignored")
+		return
+	}
+	out, err := s.payments.RefundOrderFullAs(ctx, ref.OrderID, providerYooKassa, refund.ID)
+	if err != nil {
+		if errors.Is(err, payments.ErrOrderNotPaid) {
+			s.log.Warn("yookassa refund notify: the order was never credited",
+				zap.String("order", ref.OrderID.String()), zap.String("refund", refund.ID))
+			c.String(http.StatusOK, "ignored")
+			return
+		}
+		s.log.Error("yookassa refund notify: reversal failed",
+			zap.String("order", ref.OrderID.String()), zap.String("refund", refund.ID), zap.Error(err))
+		c.String(http.StatusInternalServerError, "error")
+		return
+	}
+	if !out.AlreadyRefunded {
+		s.log.Info("yookassa refund notify: reversed a refund issued outside the console",
+			zap.String("order", ref.OrderID.String()), zap.String("refund", refund.ID),
+			zap.Int("revoked", out.Revoked), zap.Int("loss", out.Loss))
+	}
+	c.String(http.StatusOK, "ok")
+}
+
 // confirmYooKassaPayment re-reads a payment from the API — the authenticity check for the whole rail,
 // since notifications are unsigned. The shop is chosen by the shop id the payment claims to have been
 // paid to, falling back to the merchant channel recorded on the order; a claim naming a shop we do
@@ -305,9 +397,20 @@ func (s *Server) refundYooKassa(ctx context.Context, ref payments.OrderRef) (str
 	if refund.ID == "" {
 		return "", errors.New("the provider returned a refund with no id")
 	}
+	// Only a completed refund is recorded. A refund can still be canceled while pending, and the
+	// ledger is append-only, so recording early would mean revoking a customer's chips for money that
+	// then stayed with us — with no way to take the row back.
+	if refund.Status != yookassa.StatusSucceeded {
+		return "", fmt.Errorf("%w (status %s)", errRefundNotFinal, refund.Status)
+	}
 	return refund.ID, nil
 }
 
+// errRefundNotFinal reports that the provider accepted the refund but has not completed it. Retrying
+// is safe and is the way out: the idempotency key returns the same refund rather than paying twice,
+// so the operator can press again until it settles.
+var errRefundNotFinal = errors.New("the provider has not completed the refund yet")
+
 // ReconcileYooKassaOrders asks YooKassa what became of every pending order that reached its expiry
 // age while carrying a payment id, and credits the ones that were in fact paid. It is the safety net
 // for a notification that was lost for good: YooKassa redelivers for 24 hours, so a short outage

backend/internal/yookassa/notify.go

@@ -14,8 +14,9 @@ const (
 	// EventPaymentCanceled means the payment was actively declined or abandoned; nothing is credited
 	// and the payer is told the attempt failed.
 	EventPaymentCanceled = "payment.canceled"
-	// EventRefundSucceeded reports a completed refund. Refunds here are always initiated by an
-	// operator through the API, which records them synchronously, so this event is informational.
+	// EventRefundSucceeded reports a completed refund. It matters because the merchant cabinet is a
+	// second way to issue one: a refund made there never passes through our API, so without this
+	// event the money would go back while the chips stayed credited.
 	EventRefundSucceeded = "refund.succeeded"
 )
 
@@ -58,6 +59,19 @@ func (n Notification) Payment() (Payment, error) {
 	return p, nil
 }
 
+// Refund decodes the notification's object as a refund. Use it only for refund.* events; it yields
+// the refund id to re-read, never the refund state to act on.
+func (n Notification) Refund() (Refund, error) {
+	var r Refund
+	if err := json.Unmarshal(n.Object, &r); err != nil {
+		return Refund{}, fmt.Errorf("yookassa: decode notification refund: %w", err)
+	}
+	if r.ID == "" {
+		return Refund{}, fmt.Errorf("yookassa: notification refund has no id")
+	}
+	return r, nil
+}
+
 // senderPrefixes are the address ranges YooKassa delivers notifications from
 // (https://yookassa.ru/developers/using-api/webhooks). Single addresses are expressed as /32 and
 // /128 prefixes. The list is defence in depth only — the confirming GetPayment is what actually

backend/internal/yookassa/notify_test.go

@@ -88,3 +88,33 @@ func TestAllowedSenderUnmapsIPv4(t *testing.T) {
 		t.Error("an IPv4-mapped foreign sender was allowed")
 	}
 }
+
+func TestParseRefundNotification(t *testing.T) {
+	n, err := ParseNotification([]byte(`{"type":"notification","event":"refund.succeeded",
+		"object":{"id":"refund-1","status":"succeeded","payment_id":"pay-1",
+		"amount":{"value":"149.00","currency":"RUB"}}}`))
+	if err != nil {
+		t.Fatalf("parse notification: %v", err)
+	}
+	if n.Event != EventRefundSucceeded {
+		t.Errorf("event = %q, want %q", n.Event, EventRefundSucceeded)
+	}
+	r, err := n.Refund()
+	if err != nil {
+		t.Fatalf("decode notification refund: %v", err)
+	}
+	// The refund names the payment, not our order — that is how it is resolved back to one.
+	if r.ID != "refund-1" || r.PaymentID != "pay-1" {
+		t.Errorf("refund = %+v, want refund-1 for pay-1", r)
+	}
+}
+
+func TestNotificationRefundNeedsAnID(t *testing.T) {
+	n, err := ParseNotification([]byte(`{"type":"notification","event":"refund.succeeded","object":{"status":"succeeded"}}`))
+	if err != nil {
+		t.Fatalf("parse notification: %v", err)
+	}
+	if _, err := n.Refund(); err == nil {
+		t.Error("a refund object with no id was accepted")
+	}
+}

backend/internal/yookassa/yookassa.go

@@ -207,13 +207,22 @@ func (c Config) GetPayment(ctx context.Context, paymentID string) (Payment, erro
 }
 
 // CreateRefund returns money for a succeeded payment and reports the created refund. idempotenceKey
-// guards against a double refund on a retry; callers pass the order id.
+// guards against a double refund on a retry; callers pass the order id. The returned refund is not
+// necessarily final — check Status before acting on it.
 func (c Config) CreateRefund(ctx context.Context, req RefundRequest, idempotenceKey string) (Refund, error) {
 	var out Refund
 	err := c.do(ctx, http.MethodPost, "/refunds", req, idempotenceKey, &out)
 	return out, err
 }
 
+// GetRefund re-reads a refund by id. As with GetPayment this is the authenticity check: a refund
+// notification is unsigned, so only the object returned here may be acted on.
+func (c Config) GetRefund(ctx context.Context, refundID string) (Refund, error) {
+	var out Refund
+	err := c.do(ctx, http.MethodGet, "/refunds/"+url.PathEscape(refundID), nil, "", &out)
+	return out, err
+}
+
 // do performs one authenticated API call and decodes the result into out. A non-2xx answer is
 // returned as an *APIError carrying YooKassa's own error object when the body holds one.
 func (c Config) do(ctx context.Context, method, path string, body any, idempotenceKey string, out any) error {

backend/internal/yookassa/yookassa_test.go

@@ -223,3 +223,38 @@ func TestEndpointDefaultsToTheProductionAPI(t *testing.T) {
 		t.Errorf("endpoint = %q, want the trailing slash trimmed", got)
 	}
 }
+
+func TestGetRefundReadsTheObject(t *testing.T) {
+	cfg, got := fakeAPI(t, http.StatusOK, `{
+		"id":"refund-1","status":"succeeded","payment_id":"pay-1",
+		"amount":{"value":"149.00","currency":"RUB"}}`)
+
+	r, err := cfg.GetRefund(context.Background(), "refund-1")
+	if err != nil {
+		t.Fatalf("get refund: %v", err)
+	}
+	if got.method != http.MethodGet || got.path != "/refunds/refund-1" {
+		t.Errorf("request = %s %s, want GET /refunds/refund-1", got.method, got.path)
+	}
+	if r.Status != StatusSucceeded || r.PaymentID != "pay-1" {
+		t.Errorf("refund = %+v, want a succeeded refund of pay-1", r)
+	}
+}
+
+func TestCreateRefundReportsANonFinalStatus(t *testing.T) {
+	// A refund can be accepted and still be canceled later, so the caller must be able to see that it
+	// is not settled rather than treat any 200 as done.
+	cfg, _ := fakeAPI(t, http.StatusOK, `{
+		"id":"refund-1","status":"pending","payment_id":"pay-1",
+		"amount":{"value":"149.00","currency":"RUB"}}`)
+
+	r, err := cfg.CreateRefund(context.Background(), RefundRequest{
+		PaymentID: "pay-1", Amount: Amount{Value: "149.00", Currency: "RUB"},
+	}, "0197-order")
+	if err != nil {
+		t.Fatalf("create refund: %v", err)
+	}
+	if r.Status != StatusPending {
+		t.Errorf("status = %q, want pending surfaced to the caller", r.Status)
+	}
+}

deploy/.env.example

@@ -140,7 +140,8 @@ GATEWAY_VK_ID_CLIENT_SECRET=
 # to credit a live payment against it (and a test payment against a live shop).
 # Mapped in compose to BACKEND_YOOKASSA_*; Gitea TEST_/PROD_ secrets.
 # Set each shop's notification URL in its cabinet (Интеграция — HTTP-уведомления) to
-# ${PUBLIC_BASE_URL}/pay/yookassa/notify, events payment.succeeded + payment.canceled.
+# ${PUBLIC_BASE_URL}/pay/yookassa/notify, events payment.succeeded + payment.canceled +
+# refund.succeeded (the last one catches a refund issued in the cabinet, which bypasses our API).
 YOOKASSA_WEB_SHOP_ID=
 YOOKASSA_WEB_SECRET_KEY=
 YOOKASSA_WEB_TEST=

deploy/README.md

@@ -76,7 +76,7 @@ compose binds from this directory.
 | `GM_BASICAUTH_HASH` | secret | bcrypt hash gating `/_gm` (admin console + Grafana). Generate with `docker run --rm caddy:2-alpine caddy hash-password --plaintext '<pw>'`. |
 | `TELEGRAM_MINIAPP_URL` | derived | The Mini App URL the bot hands out in deep links / buttons. The deploy derives `PUBLIC_BASE_URL + /telegram/`; set it directly only for a local run (compose still `:?`-requires it). |
 | `EXPORT_SIGN_KEY` | secret | HMAC key signing the public finished-game export download URLs (`/dl/*`). Generate with `openssl rand -base64 32`. |
-| `BACKEND_YOOKASSA_{WEB,ANDROID}_SHOP_ID` | secret | YooKassa shop id for that channel of the direct RUB rail (cabinet: **Настройки — Магазин**, field `shopId`). Empty ⇒ that channel is unconfigured and order routing falls back to the **web** shop; no channel configured at all leaves the rail off. |
+| `BACKEND_YOOKASSA_{WEB,ANDROID}_SHOP_ID` | secret | YooKassa shop id for that channel of the direct RUB rail (cabinet: **Настройки — Магазин**, field `shopId`). Empty ⇒ that channel is unconfigured and order routing falls back to the **web** shop; no channel configured at all leaves the rail off. Each shop's **Интеграция — HTTP-уведомления** must point at `<PUBLIC_BASE_URL>/pay/yookassa/notify` with events `payment.succeeded`, `payment.canceled` and `refund.succeeded`. |
 | `BACKEND_YOOKASSA_{WEB,ANDROID}_SECRET_KEY` | secret | That shop's API secret key (cabinet: **Интеграция — Ключи API**). It is the password half of the HTTP Basic credentials on every API call. A shop id without a secret key is ignored. |
 | `BACKEND_YOOKASSA_{WEB,ANDROID}_TEST` | **variable** | `1` marks the credentials as a **test shop**: the intake then refuses to credit anything but a test payment (and a live shop refuses a test one). A variable, not a secret, so switching a contour between a test and a live shop is a flag flip + redeploy. |
 | `BACKEND_YOOKASSA_VAT_CODE` | **variable** | VAT rate code stamped on every fiscal receipt line (54-ФЗ tag 1199): `1` = «Без НДС» (УСН/ПСН), `4` = 20%, `11` = 22%. Defaults to `1`. A variable so a rate change needs no code change. **Confirm it with the accountant before the first real payment** — a wrong rate produces wrong receipts, not a failed payment, so it fails silently. |

deploy/docker-compose.yml

@@ -169,7 +169,8 @@ services:
       # Each shop credits the one direct wallet; a shop missing either credential drops that
       # channel (order routing falls back to the web shop), and no shop at all leaves the direct
       # order and notification endpoints unregistered. Notification URL (set per shop in the
-      # YooKassa cabinet): ${PUBLIC_BASE_URL}/pay/yookassa/notify.
+      # YooKassa cabinet): ${PUBLIC_BASE_URL}/pay/yookassa/notify — events payment.succeeded,
+      # payment.canceled and refund.succeeded.
       BACKEND_YOOKASSA_WEB_SHOP_ID: ${YOOKASSA_WEB_SHOP_ID:-}
       BACKEND_YOOKASSA_WEB_SECRET_KEY: ${YOOKASSA_WEB_SECRET_KEY:-}
       BACKEND_YOOKASSA_WEB_TEST: ${YOOKASSA_WEB_TEST:-}

docs/PAYMENTS.md

@@ -303,14 +303,28 @@ an abandoned pending) is surfaced to the user; "payment succeeded" is a hook (em
 message).
 
 **Refunds.** ToS is **non-refundable** — we do not offer refunds to the user. Refunds are
-**admin-triggered** (the E7 console), since no rail pushes an unsolicited refund. On the direct
-rail the console does the whole job in one click (D50): it calls YooKassa's refund API first
-(`POST /v3/refunds`, the order id as the `Idempotence-Key`, carrying the refund receipt of §12) and
-records the reversal only once the money has actually moved — a failed call records **nothing**, so
-the ledger can never claim a refund that did not happen. The recorded refund id is the provider's
-own, which keeps the ledger reconcilable against YooKassa's records. VK refunds are still handled by
-support and Telegram Stars refunds issued with `refundStarPayment`, both recorded by hand afterwards.
-All of them converge on one engine —
+**admin-triggered** (the E7 console). On the direct rail the console does the whole job in one click
+(D50): it calls YooKassa's refund API first (`POST /v3/refunds`, the order id as the
+`Idempotence-Key`, carrying the refund receipt of §12) and records the reversal only once the money
+has actually moved — a failed call records **nothing**, so the ledger can never claim a refund that
+did not happen. A refund is recorded **only in status `succeeded`**: one still `pending` can yet be
+canceled, and the ledger is append-only, so recording early could revoke a customer's chips for money
+that stayed with us. Pressing again is the way out — the idempotency key returns the same refund
+rather than paying twice. The recorded refund id is the provider's own, which keeps the ledger
+reconcilable against YooKassa's records.
+
+**The cabinet is a second entry point (D52).** Unlike the earlier rails, YooKassa lets an operator
+refund from the merchant cabinet, and such a refund never passes through our API — so the money would
+go back while the chips stayed credited. The `refund.succeeded` notification closes that: the refund
+is re-read from the API (the body is no more evidence than a payment notification's), bound back to
+the order through the payment id we recorded, and reversed through the same engine — idempotent on
+`(provider, refund id)`, so the notification for a refund the console already recorded reverses
+nothing twice. The engine is **full-refund-only** by design (it revokes exactly what the pack funded
+and rejects any other amount), so a **partial** refund is recorded as nothing at all and logged
+loudly for an operator: there is no non-arbitrary way to decide how many chips a part-refund costs.
+
+VK refunds are still handled by support and Telegram Stars refunds issued with `refundStarPayment`,
+both recorded by hand afterwards. All of them converge on one engine —
 the `Refund` method (`internal/payments`): it matches the paid order, appends a **refund** ledger
 row (idempotent on `(provider, provider_refund_id)` — the refund id is distinct from the fund's
 payment id, so the two rows coexist under the same partial-unique index), and **best-effort revokes

docs/PAYMENTS_DECISIONS_ru.md

@@ -309,8 +309,20 @@ web+PWA / native Android+iOS через Capacitor). Владелец (самоз
 - **D50. Возвраты на direct-рельсе — через API ЮKassa, одним действием.** Кнопка возврата в `/_gm`
   сперва двигает деньги (`POST /v3/refunds`, `Idempotence-Key` = идентификатор заказа, с чеком
   возврата) и только потом пишет реверс в журнал; неудачный вызов не пишет **ничего** — журнал не
-  может заявить о возврате, которого не было. Записывается собственный refund-id провайдера (сверка с
+  может заявить о возврате, которого не было. Реверс пишется **только при статусе `succeeded`**:
+  возврат в `pending` ещё может отмениться, а журнал только на добавление, поэтому ранняя запись
+  отобрала бы у покупателя Фишки за деньги, оставшиеся у нас; выход — нажать ещё раз, ключ
+  идемпотентности вернёт тот же возврат. Записывается собственный refund-id провайдера (сверка с
   данными ЮKassa). VK и TG Stars — как раньше: деньги руками, запись фактом.
+- **D52. Обрабатываем `refund.succeeded`: кабинет — вторая точка входа для возврата.** В отличие от
+  прежних рельсов, у ЮKassa возврат можно оформить прямо в кабинете магазина, минуя наш API, — тогда
+  деньги ушли бы назад, а Фишки остались бы начисленными, и молча. Поэтому подписываемся на событие и
+  проводим возврат тем же движком: возврат перечитывается из API (тело уведомления — не доказательство,
+  как и у платежа), привязывается к заказу через записанный идентификатор платежа, идемпотентность по
+  `(провайдер, refund-id)` делает уведомление о возврате, уже записанном консолью, пустой операцией.
+  **Частичный возврат не записываем вовсе** — движок по устройству работает только с полной суммой
+  заказа, а непроизвольного способа решить, скольких Фишек стоит часть возврата, нет; вместо записи —
+  громкий лог для оператора.
 - **D51. Фискализация — «Чеки от ЮKassa», чек отправляем из кода.** Ревизия D41: у ЮKassa нет
   кабинетного «обобщённого чека», как у Robokassa, — чек регистрируется **только если запрос его
   несёт**, поэтому itemized-код, от которого отказались в D41, возвращается в объём. Каждый платёж и
@@ -336,7 +348,7 @@ web+PWA / native Android+iOS через Capacitor). Владелец (самоз
   ведёт к пропускам. Текст — только для фиксации решённого и пояснений. Усилить
   feedback-память `prefer-interview-mode` после plan mode.
 
-## Все развилки закрыты (D1-D51)
+## Все развилки закрыты (D1-D52)
 
 Интервью завершено. Дальше — оформление документов и реализация по релизам.
 
@@ -355,6 +367,10 @@ D47-D51 — консервация Robokassa с откатом по кредам
 у ЮKassa **есть** тестовый режим (отдельный тестовый магазин со своими креды и тестовыми картами),
 поэтому весь путь проверяется на тестовом контуре без реальных денег.
 
+**Уточнение по возвратам (владелец, 2026-07-28).** D50 дополнена требованием статуса `succeeded`;
+добавлена D52 — обработка `refund.succeeded`, потому что кабинет ЮKassa позволяет вернуть деньги
+мимо нашего API. Обе правки вошли в тот же PR, что и переход на рельс.
+
 ## План внедрения (черновик PLAN.md — «слоями»)
 
 Владелец выбрал слоёную стратегию: сначала вся механика без реальных денег (обкатка

docs/PAYMENTS_ru.md

@@ -298,13 +298,28 @@ at-least-once + идемпотентный приём (дедуп по `telegram
 бота).
 
 **Возвраты.** ToS — **невозвратно**, пользователю возврат не предлагаем. Возвраты **инициирует
-админ** (консоль E7): ни один рельс не шлёт непрошеный возврат. На direct-рельсе консоль делает
-всю работу одним нажатием (D50): сперва вызывает refund-API ЮKassa (`POST /v3/refunds`,
-`Idempotence-Key` — идентификатор заказа, с чеком возврата из §12) и записывает реверс только после
-того, как деньги действительно ушли, — неудачный вызов не пишет **ничего**, поэтому журнал не может
-заявить о возврате, которого не было. Записывается собственный refund-id провайдера: по нему журнал
-сверяется с данными ЮKassa. Возвраты VK по-прежнему через поддержку, TG Stars — вызовом
-`refundStarPayment`, оба фиксируются руками после факта. Все сходятся на одном движке — метод `Refund`
+админ** (консоль E7). На direct-рельсе консоль делает всю работу одним нажатием (D50): сперва
+вызывает refund-API ЮKassa (`POST /v3/refunds`, `Idempotence-Key` — идентификатор заказа, с чеком
+возврата из §12) и записывает реверс только после того, как деньги действительно ушли, — неудачный
+вызов не пишет **ничего**, поэтому журнал не может заявить о возврате, которого не было. Возврат
+записывается **только в статусе `succeeded`**: ещё не завершённый (`pending`) может отмениться, а
+журнал только на добавление, поэтому ранняя запись отобрала бы у покупателя Фишки за деньги, оставшиеся у
+нас. Выход — нажать ещё раз: ключ идемпотентности вернёт тот же возврат, а не заплатит дважды.
+Записывается собственный refund-id провайдера: по нему журнал сверяется с данными ЮKassa.
+
+**Кабинет — вторая точка входа (D52).** В отличие от прежних рельсов, ЮKassa позволяет оформить
+возврат прямо в кабинете магазина, и такой возврат не проходит через наш API — деньги ушли бы назад,
+а Фишки остались бы начисленными. Это закрывает уведомление `refund.succeeded`: возврат
+перечитывается из API (тело уведомления — такое же не-доказательство, как и у платежа), привязывается
+к заказу через идентификатор платежа, который мы записали, и проводится тем же движком —
+идемпотентно по `(провайдер, refund-id)`, поэтому уведомление о возврате, уже записанном консолью,
+ничего не отзывает повторно. Движок по устройству работает **только с полным возвратом** (отзывает
+ровно то, что профондировал пакет, и отвергает любую другую сумму), поэтому **частичный** возврат не
+записывается вовсе и громко логируется для оператора: непроизвольного способа решить, скольких Фишек
+стоит часть возврата, нет.
+
+Возвраты VK по-прежнему через поддержку, TG Stars — вызовом `refundStarPayment`, оба фиксируются
+руками после факта. Все сходятся на одном движке — метод `Refund`
 (`internal/payments`): матчит оплаченный заказ, пишет **refund**-строку журнала (идемпотентно по
 `(provider, provider_refund_id)` — refund-id отличается от payment-id fund'а, поэтому строки
 сосуществуют под тем же partial-unique индексом) и **по возможности отзывает начисленные Фишки с