Merge pull request 'feat(payments): Telegram Stars payment rail' (#226) from feature/payment-intake-tg-stars into development

The wallet order flow plus the Telegram Stars openInvoice / VK order-box launch
and the per-button in-flight state ride the always-loaded Wallet screen, which
crossed the 123 KB gzip ceiling. Bump to 125 (matching the established
feature-driven budget history in the comment) with ~2 KB of headroom.

.gitea/workflows/ci.yaml

@@ -366,6 +366,13 @@ jobs:
           SMTP_RELAY_HOST: ${{ vars.SMTP_RELAY_HOST }}
           SMTP_RELAY_PORT: ${{ vars.SMTP_RELAY_PORT }}
           SMTP_RELAY_TLS: ${{ vars.SMTP_RELAY_TLS }}
+          # Direct-rail (Robokassa) sandbox intake on the contour: the test shop's merchant login +
+          # Password1/Password2. IsTest is forced to 1 below so the contour can never take real money
+          # (independent of the shop's own mode). Empty login leaves the direct rail off.
+          ROBOKASSA_MERCHANT_LOGIN: ${{ secrets.TEST_BACKEND_ROBOKASSA_MERCHANT_LOGIN }}
+          ROBOKASSA_PASSWORD1: ${{ secrets.TEST_BACKEND_ROBOKASSA_PASSWORD1 }}
+          ROBOKASSA_PASSWORD2: ${{ secrets.TEST_BACKEND_ROBOKASSA_PASSWORD2 }}
+          ROBOKASSA_TEST: "1"
           SMTP_RELAY_FROM: ${{ vars.TEST_SMTP_RELAY_FROM }}
           # Operator alerts: backend admin emails (new feedback / complaints) + Grafana
           # infra alerts. Distinct senders + recipients; Grafana uses the relay's STARTTLS
@@ -497,6 +504,38 @@ jobs:
           docker logs --tail 50 scrabble-backend || true
           exit 1
 
+      - name: Probe the /offer/ public offer page is served
+        run: |
+          set -u
+          # /offer/ is a static page baked into the landing image (rendered from
+          # ui/legal/offer_ru.md). If the landing Caddyfile stops routing it, the request
+          # silently falls through to the landing shell (also 200) — so assert offer-specific
+          # content, never just the status.
+          out="$(docker run --rm --network edge alpine:3.20 wget -q -O - http://scrabble/offer/ 2>&1 || true)"
+          if echo "$out" | grep -q "290210610742"; then
+            echo "ok: /offer/ serves the public offer page"
+          else
+            echo "FAIL: /offer/ did not serve the offer page (fell through to the landing shell?)"
+            docker logs --tail 50 scrabble-landing || true
+            exit 1
+          fi
+
+      - name: Probe the /pay/ callback route reaches the gateway
+        run: |
+          set -u
+          # /pay/robokassa/result must reach the gateway, not fall to the landing catch-all. An
+          # unsigned probe is rejected downstream, so the gateway answers a 4xx/5xx (never a 200 or
+          # a 404 landing.html), which proves the edge route is wired.
+          out="$(docker run --rm --network edge alpine:3.20 wget -S -q -O /dev/null http://scrabble/pay/robokassa/result 2>&1 || true)"
+          echo "$out" | grep -E "HTTP/" || true
+          if echo "$out" | grep -qE "HTTP/1\.1 (4|5)[0-9][0-9]"; then
+            echo "ok: /pay/ reaches the gateway (non-landing response)"
+          else
+            echo "FAIL: /pay/robokassa/result did not reach the gateway (landing catch-all?)"
+            docker logs --tail 50 scrabble-gateway || true
+            exit 1
+          fi
+
       - name: Probe the /dict edge route reaches the gateway
         run: |
           set -u

PLAN.md

@@ -33,8 +33,8 @@ status — without re-deriving decisions.
 | E1 | Trusted platform signal | 1 | DONE |
 | E2 | Currency + benefit core | 1 | DONE |
 | E3 | Wallet UI | 1 | DONE |
-| E4 | Durability (PITR) | 2 | WIP |
+| E4 | Durability (PITR) | 2 | DONE |
-| E5 | Payment intake | 2 | TODO |
+| E5 | Payment intake | 2 | WIP |
 | E6 | Ads | 2 | TODO |
 | E7 | Admin & reports | 2 | TODO |
 | E8 | Guest limits | — | TODO |
@@ -446,8 +446,8 @@ noun agreement). Svelte whitespace/`$state` naming gotchas apply.
 
 ## E4 — Durability (PITR)
 
-**Status:** WIP — repo artifacts landed; **prod arming pending** (owner-coordinated, before
+**Status:** DONE — armed + restore-drilled on prod (v1.13.0, 2026-07-09). · **Release 2** ·
-E5). · **Release 2** · depends on: E0 (schema exists) · mechanics: PAYMENTS §14 (D4).
+depends on: E0 (schema exists) · mechanics: PAYMENTS §14 (D4).
 
 **Goal.** Continuous WAL archiving with point-in-time recovery, armed **before the first
 real money** is accepted (E5 prod). Protects both money and game data.
@@ -479,30 +479,63 @@ real money** is accepted (E5 prod). Protects both money and game data.
   `-n backend`, silently excluding `payments`); manual-restore runbook updated.
 - Full PITR runbook + arming sequence + recorded assessment in `deploy/README.md`.
 
-**Prod arming (SEPARATE — owner-coordinated, before E5; NOT the artifacts PR).** Owner creates
+**Prod arming (completed 2026-07-09 with the v1.13.0 release).** Owner created the Selectel S3
-the Selectel S3 bucket + the `PROD_PGBACKREST_*` secrets/variables (incl. `ARCHIVE_MODE=on`);
+bucket (`erudite`, ru-6) + the `PROD_PGBACKREST_*` secrets/variables (incl. `ARCHIVE_MODE=on`);
-then promote `development → master` → `prod-deploy` (archive_mode on behind the maintenance
+promoted `development → master` → `prod-deploy` (archive_mode on behind the maintenance window),
-window), `pgbackrest stanza-create` + first base backup + `check`, re-run Ansible with
+then `stanza-create` + first base backup (31.9 MB cluster → 3.7 MB in the repo) + `check`, the
-`-e pitr_enabled=true`, and run the restore drill on an isolated one-shot target. Exact steps:
+Ansible `-e pitr_enabled=true` timer, and a restore drill on an isolated one-shot target (data
-`deploy/README.md` (point-in-time recovery — arming).
+intact, then wiped). Exact steps: `deploy/README.md` (point-in-time recovery — arming).
 
 **Tests.** Restore drill on an isolated one-shot instance (base + WAL → target timestamp),
 recorded in `deploy/README.md`. No app-level tests. Local verification: `docker compose config`
 valid + the custom PG image builds (archiving inert on the contour).
 
-**Done-criteria.** Artifacts merged with archiving inert. **Fully done** at arming: WAL
+**Done-criteria (met).** WAL archiving live on prod PG (v1.13.0); a restore verified on an
-archiving live on prod PG; a timed restore verified; cost + perf assessment reviewed; runbook
+isolated one-shot target; cost + perf assessment reviewed; runbook current in
-current in `deploy/README.md`.
+`deploy/README.md`.
 
 **Notes/risks.** The repository **cipher passphrase is unrecoverable if lost** — stored apart
-from the S3 keys. Enabling `archive_mode` restarts postgres (rides the prod-deploy maintenance
+from the S3 keys. Manual/timer pgBackRest runs use `docker exec -u postgres … --pg1-user=scrabble`
-window). Migrations stay expand-contract so image rollback remains DB-safe alongside PITR.
+(docker exec is root; the DB superuser role is `scrabble`, not `postgres`) — the systemd timer
++ the runbook carry this. Enabling `archive_mode` restarts postgres (rode the prod-deploy
+maintenance window). Migrations stay expand-contract so image rollback remains DB-safe with PITR.
 
 ---
 
 ## E5 — Payment intake
 
-**Status:** TODO · **Release 2** · depends on: E0, E1, E2, E4 · mechanics: PAYMENTS §9, §12.
+**Status:** WIP · **Release 2** · depends on: E0, E1, E2, E4 · mechanics: PAYMENTS §9, §12.
+
+**Delivery & baked decisions.** Shipped as a linear PR stack (owner's choice), Robokassa first.
+Resolved: match the order by a Robokassa **`Shp_order`** custom parameter, not the numeric `InvId`
+(an order id is a uuid); idempotency key = the order id (`provider_payment_id = order_id`); the НПД
+receipt is formed **shop-side in the Robokassa cabinet**, so no `Receipt` parameter is sent; a
+chargeback **never drives the balance negative** (D27 stands, `balances_chips_chk` kept), so E5 is
+**schema-free** (no migration, no contour wipe). Delivered on `feature/payment-intake-robokassa`:
+the offer page (`/offer/`), the order/`fund` engine (idempotent, honours an expired order), the
+`internal/robokassa` adapter, the `POST /wallet/order` + internal Result-callback handlers (a D36
+confirmed-email gate on `direct`), the pending reaper, the `wallet.order` edge wire + the public
+`/pay/*` routes, the Wallet purchase CTA, the contour deploy env (IsTest forced), and the
+`payment_events` dispatcher — an in-app wallet-refresh push (KindNotification `"payment"`) with a
+self-closing provider-return page (the payment opens in a separate window) and a return-focus
+refetch fallback. The **VK Votes rail** is delivered too: the client opens
+`VKWebAppShowOrderBox({item: order_id})`; a two-phase signed server callback (`get_item` → the pack
+title + vote price; a chargeable `order_status_change` → the same `Fund` with source=`vk`, idempotent
+on VK's own order id) is verified at the gateway with the app protected key (`GATEWAY_VK_APP_SECRET`,
+already deployed) and proxied to the backend intake. The **Telegram Stars rail** is delivered on
+`feature/payment-intake-tg-stars`: only the bot reaches Telegram, so the **invoice is minted by the
+bot** — on the `wallet.order` path the gateway sends a new `CreateInvoice` command over the reverse
+bot-link and the bot returns the `createInvoiceLink` (XTR) in its Ack, handed to the client's
+`WebApp.openInvoice`. The bot answers `pre_checkout_query` via a new bot→gateway **`ValidatePreCheckout`**
+unary (backed by the backend: the order must exist, be still creditable and **not already paid** — the
+reusable-invoice double-pay guard — with a matching amount); the decline reason is localised to the
+order account's language. A completed `successful_payment` is persisted to a pure-Go **SQLite outbox**
+(`modernc.org/sqlite`) then forwarded by a new bot→gateway **`ForwardPayment`** unary into the same
+`Fund` (source=`telegram`, idempotent on `telegram_payment_charge_id`, honours an expired order),
+re-driven at startup and every 30 s. The rail is wired by `TELEGRAM_STARS_OUTBOX_DIR` (defaults to the
+bot `/data` volume) but stays **inert until a chip pack carries an XTR price**, so seeding a Stars price
+in the admin is the go-live. Remaining: refunds; and hiding the ad banner on a no-ads purchase (a
+spend-path `NotifyBanner`, deferred with the owner's agreement).
 
 **Goal.** Accept real money on all three rails into the payments domain: order-flow,
 verified provider callbacks, idempotency, the TG bot SQLite outbox, the event dispatcher,
@@ -525,12 +558,14 @@ receipts, and refunds.
 
 **TG bot outbox (`platform/telegram/`).**
 
-- The bot receives `successful_payment` (and `pre_checkout_query`) via Bot API. Add a
+- The bot receives `successful_payment` (and `pre_checkout_query`) via Bot API. A **SQLite**
-  **SQLite** store on the bot's disk: on receipt, persist → ack the Telegram update → forward
+  store on the bot's disk (`internal/outbox`): on receipt, persist → forward over the reverse
-  to a backend payments-intake endpoint (internal, authenticated over the existing reverse
+  mTLS bot-link to the **gateway** (a `ForwardPayment` unary; the bot cannot dial the backend
-  mTLS bot-link) → on backend ack, mark `forwarded`. Retries with backoff; re-drive
+  directly) → the gateway proxies to the backend payments-intake REST → on a durable response,
-  undelivered on restart. Backend intake dedups by `telegram_payment_charge_id`.
+  mark `forwarded`. Re-drive undelivered on startup and on a 30 s tick. Backend intake dedups by
-- Provide the invoice creation path (Stars) from the Mini App via the bot as needed.
+  `telegram_payment_charge_id`.
+- Invoice creation (Stars) is minted by the bot (`createInvoiceLink`, XTR) on the gateway's
+  `CreateInvoice` bot-link command, returned to the Mini App as the `openInvoice` link.
 
 **Events & notifications.**
 

backend/cmd/backend/main.go

@@ -308,6 +308,7 @@ func run(ctx context.Context, cfg config.Config, logger *zap.Logger) error {
 		Notifier:      hub,
 		ExportSignKey: cfg.ExportSignKey,
 		Renderer:      renderer,
+		Robokassa:     cfg.Robokassa,
 	})
 	pushSrv := pushgrpc.NewServer(cfg.GRPCAddr, hub, logger)
 
@@ -316,6 +317,13 @@ func run(ctx context.Context, cfg config.Config, logger *zap.Logger) error {
 	logger.Info("servers starting",
 		zap.String("http_addr", cfg.HTTPAddr),
 		zap.String("grpc_addr", cfg.GRPCAddr))
+	// Sweep expired pending payment orders on a cadence (cosmetic hygiene; a late valid callback
+	// still credits). Runs until ctx is cancelled.
+	go runOrderReaper(ctx, paymentsSvc, logger)
+	// Deliver pending payment_events to connected clients as an in-app wallet-refresh push (the
+	// credit already landed in the ledger; a return-focus poll is the client-side fallback).
+	go runPaymentDispatcher(ctx, paymentsSvc, hub, logger)
+
 	errc := make(chan error, 2)
 	go func() { errc <- pushSrv.Run(ctx) }()
 	go func() { errc <- srv.Run(ctx) }()
@@ -325,6 +333,52 @@ func run(ctx context.Context, cfg config.Config, logger *zap.Logger) error {
 	return err
 }
 
+// runOrderReaper periodically expires pending payment orders past their configured lifetime, until
+// ctx is cancelled. Expiry is cosmetic: a later valid provider callback still credits an expired
+// order.
+func runOrderReaper(ctx context.Context, p *payments.Service, log *zap.Logger) {
+	t := time.NewTicker(5 * time.Minute)
+	defer t.Stop()
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case <-t.C:
+			if n, err := p.ExpireOrders(ctx); err != nil {
+				log.Warn("order reaper: sweep failed", zap.Error(err))
+			} else if n > 0 {
+				log.Info("order reaper: expired pending orders", zap.Int("count", n))
+			}
+		}
+	}
+}
+
+// runPaymentDispatcher delivers pending payment_events to connected clients as a wallet-refresh
+// signal (KindNotification / "payment"), marking each delivered, until ctx is cancelled. The credit
+// already committed to the ledger; this is only the in-app push so an open wallet updates in place.
+func runPaymentDispatcher(ctx context.Context, p *payments.Service, pub notify.Publisher, log *zap.Logger) {
+	t := time.NewTicker(3 * time.Second)
+	defer t.Stop()
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case <-t.C:
+			evs, err := p.UndispatchedEvents(ctx, 50)
+			if err != nil {
+				log.Warn("payment dispatcher: read failed", zap.Error(err))
+				continue
+			}
+			for _, e := range evs {
+				pub.Publish(notify.Notification(e.AccountID, notify.NotifyPayment))
+				if err := p.MarkEventDispatched(ctx, e.EventID); err != nil {
+					log.Warn("payment dispatcher: mark failed", zap.String("event", e.EventID.String()), zap.Error(err))
+				}
+			}
+		}
+	}
+}
+
 // newMailer builds the confirm-code mailer: an SMTP relay when a host is
 // configured, otherwise the development log mailer (the code is logged, not sent).
 func newMailer(cfg account.SMTPConfig, logger *zap.Logger) account.Mailer {

backend/internal/account/account.go

@@ -393,6 +393,21 @@ func (s *Store) Identities(ctx context.Context, accountID uuid.UUID) ([]Identity
 	return out, nil
 }
 
+// HasConfirmedEmail reports whether the account owns a confirmed email identity — the direct-rail
+// recovery anchor a first purchase requires (D36).
+func (s *Store) HasConfirmedEmail(ctx context.Context, accountID uuid.UUID) (bool, error) {
+	ids, err := s.Identities(ctx, accountID)
+	if err != nil {
+		return false, err
+	}
+	for _, id := range ids {
+		if id.Kind == "email" && id.Confirmed {
+			return true, nil
+		}
+	}
+	return false, nil
+}
+
 // ListAccounts returns accounts for the admin user list, newest first, paginated
 // by limit and offset.
 func (s *Store) ListAccounts(ctx context.Context, limit, offset int) ([]Account, error) {

backend/internal/config/config.go

@@ -14,6 +14,7 @@ import (
 	"scrabble/backend/internal/lobby"
 	"scrabble/backend/internal/postgres"
 	"scrabble/backend/internal/ratewatch"
+	"scrabble/backend/internal/robokassa"
 	"scrabble/backend/internal/robot"
 	"scrabble/backend/internal/telemetry"
 )
@@ -64,6 +65,9 @@ type Config struct {
 	// RendererURL is the base URL of the internal image-render sidecar (e.g.
 	// http://renderer:8090). Empty disables the PNG export artifact.
 	RendererURL string
+	// Robokassa configures the direct-rail (RUB) payment provider. An empty MerchantLogin
+	// leaves the direct order and Result-callback endpoints unregistered.
+	Robokassa robokassa.Config
 }
 
 // Defaults applied when the corresponding environment variable is unset.
@@ -153,6 +157,13 @@ func Load() (Config, error) {
 		AdminTo:   os.Getenv("BACKEND_ADMIN_EMAIL"),
 	}
 
+	robo := robokassa.Config{
+		MerchantLogin: os.Getenv("BACKEND_ROBOKASSA_MERCHANT_LOGIN"),
+		Password1:     os.Getenv("BACKEND_ROBOKASSA_PASSWORD1"),
+		Password2:     os.Getenv("BACKEND_ROBOKASSA_PASSWORD2"),
+		IsTest:        os.Getenv("BACKEND_ROBOKASSA_TEST") == "1",
+	}
+
 	c := Config{
 		HTTPAddr:          envOr("BACKEND_HTTP_ADDR", defaultHTTPAddr),
 		GRPCAddr:          envOr("BACKEND_GRPC_ADDR", defaultGRPCAddr),
@@ -170,6 +181,7 @@ func Load() (Config, error) {
 		GuestRetention:    guestRetention,
 		ExportSignKey:     os.Getenv("BACKEND_EXPORT_SIGN_KEY"),
 		RendererURL:       os.Getenv("BACKEND_RENDERER_URL"),
+		Robokassa:         robo,
 	}
 	if err := c.validate(); err != nil {
 		return Config{}, err
@@ -222,6 +234,9 @@ func (c Config) validate() error {
 			return fmt.Errorf("config: BACKEND_PUBLIC_BASE_URL %q must be an absolute URL (scheme://host)", c.PublicBaseURL)
 		}
 	}
+	if c.Robokassa.MerchantLogin != "" && (c.Robokassa.Password1 == "" || c.Robokassa.Password2 == "") {
+		return fmt.Errorf("config: BACKEND_ROBOKASSA_PASSWORD1 and BACKEND_ROBOKASSA_PASSWORD2 must be set when BACKEND_ROBOKASSA_MERCHANT_LOGIN is")
+	}
 	return nil
 }
 

backend/internal/inttest/payments_intake_test.go

@@ -0,0 +1,328 @@
+//go:build integration
+
+package inttest
+
+import (
+	"context"
+	"errors"
+	"testing"
+
+	"github.com/google/uuid"
+
+	"scrabble/backend/internal/payments"
+)
+
+// orderStatus reads an order's status.
+func orderStatus(t *testing.T, orderID uuid.UUID) string {
+	t.Helper()
+	var status string
+	if err := testDB.QueryRowContext(context.Background(),
+		`SELECT status FROM payments.orders WHERE order_id=$1`, orderID).Scan(&status); err != nil {
+		t.Fatalf("read order status: %v", err)
+	}
+	return status
+}
+
+// TestPaymentsOrderFundCreditsOnce verifies the intake path over Postgres: creating an order then
+// funding it credits the funded segment exactly once, and a replayed callback (the same order)
+// credits nothing more — the ledger idempotency index holds.
+func TestPaymentsOrderFundCreditsOnce(t *testing.T) {
+	ctx := context.Background()
+	svc := newPaymentsService()
+	acc := uuid.New()
+	prod := seedPackProduct(t, 100, methodPrice{method: "direct", currency: "RUB", amount: 14900}) // 149.00 RUB funds 100 chips
+
+	res, err := svc.CreateOrder(ctx, acc, payments.NewContext("direct", "web"), []payments.Source{payments.SourceDirect}, prod, "robokassa")
+	if err != nil {
+		t.Fatalf("create order: %v", err)
+	}
+	if res.Amount.Minor() != 14900 || res.Amount.Currency() != payments.CurrencyRUB {
+		t.Fatalf("order amount = %s, want 149.00 RUB", res.Amount)
+	}
+	if orderStatus(t, res.OrderID) != "pending" {
+		t.Errorf("new order status = %s, want pending", orderStatus(t, res.OrderID))
+	}
+
+	paid, _ := payments.MoneyFromMinor(14900, payments.CurrencyRUB)
+	out, err := svc.Fund(ctx, res.OrderID, "robokassa", res.OrderID.String(), paid)
+	if err != nil {
+		t.Fatalf("fund: %v", err)
+	}
+	if out.AlreadyCredited || out.Chips != 100 || out.Source != payments.SourceDirect {
+		t.Fatalf("fund outcome = %+v, want 100 chips to direct, not already-credited", out)
+	}
+	if got := readBalance(t, acc, "direct"); got != 100 {
+		t.Errorf("balance after fund = %d, want 100", got)
+	}
+	if ledgerRows(t, acc, "fund") != 1 {
+		t.Errorf("fund ledger rows = %d, want 1", ledgerRows(t, acc, "fund"))
+	}
+	if orderStatus(t, res.OrderID) != "paid" {
+		t.Errorf("order status after fund = %s, want paid", orderStatus(t, res.OrderID))
+	}
+
+	// A replayed callback for the same order is rejected by the unique index: no second credit.
+	out2, err := svc.Fund(ctx, res.OrderID, "robokassa", res.OrderID.String(), paid)
+	if err != nil {
+		t.Fatalf("duplicate fund: %v", err)
+	}
+	if !out2.AlreadyCredited {
+		t.Error("duplicate callback not flagged AlreadyCredited")
+	}
+	if got := readBalance(t, acc, "direct"); got != 100 {
+		t.Errorf("balance after duplicate = %d, want 100 (credited once)", got)
+	}
+	if ledgerRows(t, acc, "fund") != 1 {
+		t.Error("duplicate callback wrote a second fund ledger row")
+	}
+}
+
+// TestPaymentsVKOrderFundCredits exercises the VK Votes rail over Postgres: a VK order prices the
+// pack in votes; the get_item lookup returns its title and vote price; a chargeable
+// order_status_change credits the vk segment exactly once (idempotent on VK's own order id).
+func TestPaymentsVKOrderFundCredits(t *testing.T) {
+	ctx := context.Background()
+	svc := newPaymentsService()
+	acc := uuid.New()
+	prod := seedPackProduct(t, 200, methodPrice{method: "vk", currency: "VOTE", amount: 30})
+
+	res, err := svc.CreateOrder(ctx, acc, payments.NewContext("vk", "web"), []payments.Source{payments.SourceVK}, prod, "vk")
+	if err != nil {
+		t.Fatalf("create vk order: %v", err)
+	}
+	if res.Amount.Currency() != payments.CurrencyVote || res.Amount.Minor() != 30 {
+		t.Fatalf("vk order amount = %s, want 30 VOTE", res.Amount)
+	}
+
+	// get_item phase: title + vote price.
+	title, amount, err := svc.OrderItem(ctx, res.OrderID)
+	if err != nil {
+		t.Fatalf("order item: %v", err)
+	}
+	if title == "" || amount.Minor() != 30 || amount.Currency() != payments.CurrencyVote {
+		t.Errorf("order item = %q / %s, want a title + 30 VOTE", title, amount)
+	}
+
+	// order_status_change phase: VK's own order id is the idempotency key.
+	paid, _ := payments.MoneyFromMinor(30, payments.CurrencyVote)
+	out, err := svc.Fund(ctx, res.OrderID, "vk", "vk-order-777", paid)
+	if err != nil {
+		t.Fatalf("vk fund: %v", err)
+	}
+	if out.AlreadyCredited || out.Chips != 200 || out.Source != payments.SourceVK {
+		t.Fatalf("vk fund outcome = %+v, want 200 chips credited to vk", out)
+	}
+	if got := readBalance(t, acc, "vk"); got != 200 {
+		t.Errorf("vk balance after fund = %d, want 200", got)
+	}
+
+	// A duplicate VK callback (same VK order id) credits nothing more.
+	out2, err := svc.Fund(ctx, res.OrderID, "vk", "vk-order-777", paid)
+	if err != nil {
+		t.Fatalf("duplicate vk fund: %v", err)
+	}
+	if !out2.AlreadyCredited {
+		t.Error("duplicate VK callback not flagged AlreadyCredited")
+	}
+	if got := readBalance(t, acc, "vk"); got != 200 {
+		t.Errorf("vk balance after duplicate = %d, want 200 (credited once)", got)
+	}
+}
+
+// TestPaymentsTelegramStarsRail exercises the Telegram Stars rail over Postgres: an order prices the
+// pack in whole stars (XTR); a pre_checkout on the pending order is approved; the forwarded payment
+// credits the telegram segment exactly once (idempotent on the Telegram charge id); and a
+// pre_checkout after the order is paid is declined (a reusable invoice link paid twice).
+func TestPaymentsTelegramStarsRail(t *testing.T) {
+	ctx := context.Background()
+	svc := newPaymentsService()
+	acc := uuid.New()
+	prod := seedPackProduct(t, 50, methodPrice{method: "telegram", currency: "XTR", amount: 40}) // 40 stars fund 50 chips
+
+	res, err := svc.CreateOrder(ctx, acc, payments.NewContext("telegram", "android"), []payments.Source{payments.SourceTelegram}, prod, "telegram")
+	if err != nil {
+		t.Fatalf("create telegram order: %v", err)
+	}
+	if res.Amount.Currency() != payments.CurrencyStar || res.Amount.Minor() != 40 {
+		t.Fatalf("telegram order amount = %s, want 40 XTR", res.Amount)
+	}
+
+	// pre_checkout on the pending order: approved, and it reports the account for reason localisation.
+	starAmt, _ := payments.MoneyFromMinor(40, payments.CurrencyStar)
+	pc, err := svc.ValidatePreCheckout(ctx, res.OrderID, starAmt)
+	if err != nil {
+		t.Fatalf("pre_checkout: %v", err)
+	}
+	if !pc.OK || pc.AccountID != acc {
+		t.Fatalf("pre_checkout = %+v, want approved for account %s", pc, acc)
+	}
+
+	// The forwarded successful_payment credits once, idempotent on the Telegram charge id.
+	out, err := svc.Fund(ctx, res.OrderID, "telegram", "tg-charge-1", starAmt)
+	if err != nil {
+		t.Fatalf("telegram fund: %v", err)
+	}
+	if out.AlreadyCredited || out.Chips != 50 || out.Source != payments.SourceTelegram {
+		t.Fatalf("telegram fund outcome = %+v, want 50 chips credited to telegram", out)
+	}
+	if got := readBalance(t, acc, "telegram"); got != 50 {
+		t.Errorf("telegram balance after fund = %d, want 50", got)
+	}
+
+	// A retried forward (same charge id, e.g. a lost ack) credits nothing more.
+	out2, err := svc.Fund(ctx, res.OrderID, "telegram", "tg-charge-1", starAmt)
+	if err != nil {
+		t.Fatalf("duplicate telegram fund: %v", err)
+	}
+	if !out2.AlreadyCredited {
+		t.Error("retried forward not flagged AlreadyCredited")
+	}
+	if got := readBalance(t, acc, "telegram"); got != 50 {
+		t.Errorf("telegram balance after retry = %d, want 50 (credited once)", got)
+	}
+
+	// pre_checkout after the order is paid: declined (the reusable-link double-pay guard).
+	pc2, err := svc.ValidatePreCheckout(ctx, res.OrderID, starAmt)
+	if err != nil {
+		t.Fatalf("pre_checkout after paid: %v", err)
+	}
+	if pc2.OK || pc2.Reason != payments.PreCheckoutAlreadyPaid {
+		t.Errorf("pre_checkout after paid = %+v, want a decline with already_paid", pc2)
+	}
+}
+
+// TestPaymentsTelegramPreCheckoutDeclines covers the pre_checkout decline reasons: an unknown order
+// and an amount that no longer matches.
+func TestPaymentsTelegramPreCheckoutDeclines(t *testing.T) {
+	ctx := context.Background()
+	svc := newPaymentsService()
+	starAmt, _ := payments.MoneyFromMinor(40, payments.CurrencyStar)
+
+	// An unknown order id declines as gone, with no account to localise against.
+	pc, err := svc.ValidatePreCheckout(ctx, uuid.New(), starAmt)
+	if err != nil {
+		t.Fatalf("pre_checkout unknown: %v", err)
+	}
+	if pc.OK || pc.Reason != payments.PreCheckoutGone || pc.AccountID != (uuid.UUID{}) {
+		t.Errorf("pre_checkout unknown = %+v, want a gone decline with no account", pc)
+	}
+
+	// A pending order validated at the wrong amount declines as price-changed.
+	acc := uuid.New()
+	prod := seedPackProduct(t, 100, methodPrice{method: "telegram", currency: "XTR", amount: 80})
+	res, err := svc.CreateOrder(ctx, acc, payments.NewContext("telegram", "android"), []payments.Source{payments.SourceTelegram}, prod, "telegram")
+	if err != nil {
+		t.Fatalf("create telegram order: %v", err)
+	}
+	wrong, _ := payments.MoneyFromMinor(40, payments.CurrencyStar)
+	pc2, err := svc.ValidatePreCheckout(ctx, res.OrderID, wrong)
+	if err != nil {
+		t.Fatalf("pre_checkout mismatch: %v", err)
+	}
+	if pc2.OK || pc2.Reason != payments.PreCheckoutPriceChanged {
+		t.Errorf("pre_checkout mismatch = %+v, want a price_changed decline", pc2)
+	}
+}
+
+// TestPaymentsFundAmountMismatch verifies a callback whose paid amount does not match the order is
+// refused and credits nothing (§9: verify the amount after matching by order id).
+func TestPaymentsFundAmountMismatch(t *testing.T) {
+	ctx := context.Background()
+	svc := newPaymentsService()
+	acc := uuid.New()
+	prod := seedPackProduct(t, 100, methodPrice{method: "direct", currency: "RUB", amount: 14900})
+
+	res, err := svc.CreateOrder(ctx, acc, payments.NewContext("direct", "web"), []payments.Source{payments.SourceDirect}, prod, "robokassa")
+	if err != nil {
+		t.Fatalf("create order: %v", err)
+	}
+	underpaid, _ := payments.MoneyFromMinor(100, payments.CurrencyRUB)
+	if _, err := svc.Fund(ctx, res.OrderID, "robokassa", res.OrderID.String(), underpaid); !errors.Is(err, payments.ErrAmountMismatch) {
+		t.Fatalf("fund = %v, want ErrAmountMismatch", err)
+	}
+	if got := readBalance(t, acc, "direct"); got != 0 {
+		t.Errorf("balance = %d, want 0 (nothing credited on mismatch)", got)
+	}
+	if ledgerRows(t, acc, "fund") != 0 {
+		t.Error("fund ledger row written on an amount mismatch")
+	}
+}
+
+// TestPaymentsEventDispatchDrain verifies the payment_events dispatcher queue: a recorded event is
+// returned as undispatched until marked, then drops out (so the dispatcher delivers it once).
+func TestPaymentsEventDispatchDrain(t *testing.T) {
+	ctx := context.Background()
+	svc := newPaymentsService()
+	acc := uuid.New()
+	if err := svc.RecordPaymentEvent(ctx, acc, nil, "succeeded", []byte(`{"chips":10,"source":"direct"}`)); err != nil {
+		t.Fatalf("record event: %v", err)
+	}
+
+	// testDB is shared, so filter the queue to our account.
+	find := func() *payments.PaymentEvent {
+		evs, err := svc.UndispatchedEvents(ctx, 100)
+		if err != nil {
+			t.Fatalf("undispatched: %v", err)
+		}
+		for i := range evs {
+			if evs[i].AccountID == acc {
+				return &evs[i]
+			}
+		}
+		return nil
+	}
+
+	mine := find()
+	if mine == nil {
+		t.Fatal("recorded event not in the undispatched queue")
+	}
+	if mine.Type != "succeeded" {
+		t.Errorf("event type = %s, want succeeded", mine.Type)
+	}
+	if err := svc.MarkEventDispatched(ctx, mine.EventID); err != nil {
+		t.Fatalf("mark dispatched: %v", err)
+	}
+	if find() != nil {
+		t.Error("event still undispatched after MarkEventDispatched")
+	}
+}
+
+// TestPaymentsExpiredOrderStillCredits verifies an expired pending order is still honoured by a
+// later valid callback (§9/D23: expiry is cosmetic, the money is real).
+func TestPaymentsExpiredOrderStillCredits(t *testing.T) {
+	ctx := context.Background()
+	svc := newPaymentsService()
+	acc := uuid.New()
+	prod := seedPackProduct(t, 100, methodPrice{method: "direct", currency: "RUB", amount: 14900})
+
+	res, err := svc.CreateOrder(ctx, acc, payments.NewContext("direct", "web"), []payments.Source{payments.SourceDirect}, prod, "robokassa")
+	if err != nil {
+		t.Fatalf("create order: %v", err)
+	}
+	// Age the order well past the configured TTL, then sweep it to expired.
+	if _, err := testDB.ExecContext(ctx,
+		`UPDATE payments.orders SET created_at = now() - interval '1 day' WHERE order_id=$1`, res.OrderID); err != nil {
+		t.Fatalf("age order: %v", err)
+	}
+	if n, err := svc.ExpireOrders(ctx); err != nil || n < 1 {
+		t.Fatalf("expire orders = %d (err %v), want at least 1", n, err)
+	}
+	if orderStatus(t, res.OrderID) != "expired" {
+		t.Fatalf("order status = %s, want expired before the late callback", orderStatus(t, res.OrderID))
+	}
+
+	paid, _ := payments.MoneyFromMinor(14900, payments.CurrencyRUB)
+	out, err := svc.Fund(ctx, res.OrderID, "robokassa", res.OrderID.String(), paid)
+	if err != nil {
+		t.Fatalf("fund after expiry: %v", err)
+	}
+	if out.AlreadyCredited || out.Chips != 100 {
+		t.Fatalf("fund outcome = %+v, want a fresh 100-chip credit", out)
+	}
+	if got := readBalance(t, acc, "direct"); got != 100 {
+		t.Errorf("balance = %d, want 100 (expired order honoured)", got)
+	}
+	if orderStatus(t, res.OrderID) != "paid" {
+		t.Errorf("order status = %s, want paid after the honoured callback", orderStatus(t, res.OrderID))
+	}
+}

backend/internal/notify/notify.go

@@ -73,6 +73,10 @@ const (
 	// (e.g. an email was confirmed via the one-tap deeplink opened in another browser),
 	// so it re-fetches profile.get. It carries no payload. In-app only.
 	NotifyProfile = "profile"
+	// NotifyPayment tells the client that the viewer's wallet changed from a payment-intake event
+	// (a credit or a refund), so it re-fetches the wallet in place. It carries no payload. In-app
+	// only; the payment_events dispatcher emits it after the crediting transaction commits.
+	NotifyPayment = "payment"
 	// NotifyUserBlocked confirms to the blocker that a per-user block took effect,
 	// carrying the blocked account, so every one of the blocker's sessions updates the
 	// in-game block/add-friend controls and the struck name in place. It is delivered

backend/internal/payments/payments.go

@@ -147,12 +147,13 @@ func (m Money) Cmp(o Money) (int, error) {
 	}
 }
 
-// String renders the amount as "<value> <currency>", with the currency's
+// Major renders the amount as a decimal string without the currency, with the currency's
-// fractional digits and no floating point (e.g. "149.50 RUB", "250 XTR").
+// fractional digits and no floating point (e.g. "149.50", "250") — the form a provider's amount
-func (m Money) String() string {
+// field (Robokassa OutSum) takes.
+func (m Money) Major() string {
 	scale := m.currency.minorPerUnit()
 	if scale == 1 {
-		return fmt.Sprintf("%d %s", m.minor, m.currency)
+		return fmt.Sprintf("%d", m.minor)
 	}
 	neg := m.minor < 0
 	abs := m.minor
@@ -167,5 +168,10 @@ func (m Money) String() string {
 	if neg {
 		sign = "-"
 	}
-	return fmt.Sprintf("%s%d.%0*d %s", sign, abs/scale, width, abs%scale, m.currency)
+	return fmt.Sprintf("%s%d.%0*d", sign, abs/scale, width, abs%scale)
+}
+
+// String renders the amount as "<value> <currency>" (e.g. "149.50 RUB", "250 XTR").
+func (m Money) String() string {
+	return m.Major() + " " + string(m.currency)
 }

backend/internal/payments/service_intake.go

@@ -0,0 +1,153 @@
+package payments
+
+import (
+	"context"
+	"errors"
+	"fmt"
+
+	"github.com/google/uuid"
+)
+
+// OrderResult is what CreateOrder returns to the transport: the created order id and the details a
+// provider launch payload needs — the amount to charge and a human title for the payment.
+type OrderResult struct {
+	OrderID uuid.UUID
+	Amount  Money
+	Title   string
+}
+
+// CreateOrder opens a pending order to fund a chip pack in the execution context's payment method,
+// tagged with the provider that will settle it. It gate-checks the context (trusted, not the
+// VK-iOS spend freeze) and that the method's funding segment is attached, prices the pack in the
+// method's currency, then writes the order. The caller enforces any account-level precondition
+// (e.g. the direct email anchor, D36) before calling — payments holds no cross-schema identity
+// knowledge.
+func (s *Service) CreateOrder(ctx context.Context, accountID uuid.UUID, cxt Context, present []Source, productID uuid.UUID, provider string) (OrderResult, error) {
+	if !cxt.Trusted() || cxt.vkFrozen() {
+		return OrderResult{}, ErrUntrusted
+	}
+	method := cxt.Kind
+	if !has(present, method) {
+		return OrderResult{}, ErrUntrusted // the funding segment is not attached to the account
+	}
+	pack, err := s.store.loadPackForOrder(ctx, productID, method)
+	if err != nil {
+		return OrderResult{}, err
+	}
+	orderID, err := uuid.NewV7()
+	if err != nil {
+		return OrderResult{}, fmt.Errorf("payments: order id: %w", err)
+	}
+	o := newOrder{
+		orderID:   orderID,
+		accountID: accountID,
+		platform:  string(method),
+		productID: productID,
+		amount:    pack.price,
+		origin:    method,
+		provider:  provider,
+	}
+	if err := s.store.createOrder(ctx, o, s.clock()); err != nil {
+		return OrderResult{}, err
+	}
+	return OrderResult{OrderID: orderID, Amount: pack.price, Title: pack.title}, nil
+}
+
+// OrderItem returns a pending order's human title and the amount it charges, in the order's own
+// currency — the details a provider's item-lookup phase needs (VK's get_item). It reads the order
+// and the pack title, honouring the pack even if it was later deactivated (mirrors Fund).
+func (s *Service) OrderItem(ctx context.Context, orderID uuid.UUID) (title string, amount Money, err error) {
+	ord, err := s.store.orderByID(ctx, orderID)
+	if err != nil {
+		return "", Money{}, err
+	}
+	_, title, err = s.store.packForCredit(ctx, ord.productID)
+	if err != nil {
+		return "", Money{}, err
+	}
+	amount, err = MoneyFromMinor(ord.expectedAmount, Currency(ord.currency))
+	if err != nil {
+		return "", Money{}, err
+	}
+	return title, amount, nil
+}
+
+// Fund credits a paid order into its funded segment exactly once, from a verified provider callback
+// — the single writer for every rail. It matches the order, verifies the paid amount, appends the
+// fund ledger row (idempotent on (provider, provider_payment_id)), credits the balance and marks
+// the order paid. A duplicate callback returns AlreadyCredited without a second credit; a valid
+// callback is honoured even on an expired order (§9/D23).
+func (s *Service) Fund(ctx context.Context, orderID uuid.UUID, provider, providerPaymentID string, paid Money) (FundOutcome, error) {
+	return s.store.fund(ctx, orderID, provider, providerPaymentID, paid, s.clock())
+}
+
+// Pre-checkout decline reason codes. They are language-neutral: the transport layer localises them
+// to the order account's preferred language before showing the payer (the reason is displayed in the
+// Telegram payment sheet).
+const (
+	// PreCheckoutGone means no order matches — an unknown or stale invoice payload.
+	PreCheckoutGone = "order_gone"
+	// PreCheckoutAlreadyPaid means the order is already paid (a reusable invoice link paid twice).
+	PreCheckoutAlreadyPaid = "already_paid"
+	// PreCheckoutPriceChanged means the amount or currency no longer matches the order.
+	PreCheckoutPriceChanged = "price_changed"
+)
+
+// PreCheckoutOutcome is the pre-charge validation of a Telegram Stars order. OK approves the charge;
+// otherwise Reason is a decline reason code the transport localises. AccountID is the order's account
+// (for localising the reason to its preferred language); it is the zero UUID when the order is unknown.
+type PreCheckoutOutcome struct {
+	OK        bool
+	Reason    string
+	AccountID uuid.UUID
+}
+
+// ValidatePreCheckout answers whether a Stars pre_checkout_query for orderID paying amount may be
+// approved, before any star is charged. It approves an order that exists, is not already paid (a
+// reusable invoice link paid a second time is refused here) and whose expected amount and currency
+// match the invoice. A pending or honoured-expired order is approved — a late credit is honoured
+// (§9/D23). A missing order or a mismatch is a clean decline with a reason code, not an error.
+func (s *Service) ValidatePreCheckout(ctx context.Context, orderID uuid.UUID, amount Money) (PreCheckoutOutcome, error) {
+	ord, err := s.store.orderByID(ctx, orderID)
+	if errors.Is(err, ErrOrderNotFound) {
+		return PreCheckoutOutcome{OK: false, Reason: PreCheckoutGone}, nil
+	}
+	if err != nil {
+		return PreCheckoutOutcome{}, err
+	}
+	if ord.status == "paid" {
+		return PreCheckoutOutcome{OK: false, Reason: PreCheckoutAlreadyPaid, AccountID: ord.accountID}, nil
+	}
+	if amount.Currency() != Currency(ord.currency) || amount.Minor() != ord.expectedAmount {
+		return PreCheckoutOutcome{OK: false, Reason: PreCheckoutPriceChanged, AccountID: ord.accountID}, nil
+	}
+	return PreCheckoutOutcome{OK: true, AccountID: ord.accountID}, nil
+}
+
+// ExpireOrders marks pending orders older than the configured lifetime as expired, returning how
+// many were swept. It backs the periodic pending reaper; expiry is cosmetic (a late valid callback
+// still credits — see Fund).
+func (s *Service) ExpireOrders(ctx context.Context) (int, error) {
+	ttl, err := s.store.orderTTL(ctx)
+	if err != nil {
+		return 0, err
+	}
+	return s.store.expirePending(ctx, ttl, s.clock())
+}
+
+// RecordPaymentEvent appends a payment lifecycle event (succeeded/failed/refunded) for the
+// dispatcher to deliver to the user (live stream, botlink or email).
+func (s *Service) RecordPaymentEvent(ctx context.Context, accountID uuid.UUID, orderID *uuid.UUID, eventType string, payload []byte) error {
+	return s.store.insertPaymentEvent(ctx, accountID, orderID, eventType, payload, s.clock())
+}
+
+// UndispatchedEvents returns up to limit payment events awaiting delivery. The dispatcher drains
+// them and marks each delivered via MarkEventDispatched.
+func (s *Service) UndispatchedEvents(ctx context.Context, limit int) ([]PaymentEvent, error) {
+	return s.store.undispatchedEvents(ctx, limit)
+}
+
+// MarkEventDispatched stamps a payment event as delivered so it is not re-sent.
+func (s *Service) MarkEventDispatched(ctx context.Context, eventID uuid.UUID) error {
+	return s.store.markEventDispatched(ctx, eventID, s.clock())
+}

backend/internal/payments/service_intake_test.go

@@ -0,0 +1,42 @@
+package payments
+
+import (
+	"context"
+	"errors"
+	"testing"
+	"time"
+
+	"github.com/google/uuid"
+)
+
+// gateOnlyService builds a Service with a fixed clock and no store, usable only for the CreateOrder
+// gate rejections that return before any store access.
+func gateOnlyService() *Service {
+	return &Service{clock: func() time.Time { return time.Unix(0, 0).UTC() }}
+}
+
+// TestCreateOrderGateRejections checks that CreateOrder fails closed — before touching the store —
+// on an untrusted platform, the VK-iOS spend freeze, and a method whose funding segment the account
+// does not hold.
+func TestCreateOrderGateRejections(t *testing.T) {
+	ctx := context.Background()
+	acc, prod := uuid.New(), uuid.New()
+	present := []Source{SourceDirect, SourceVK}
+
+	cases := []struct {
+		name string
+		cxt  Context
+	}{
+		{"untrusted context", Context{}},
+		{"vk-ios spend freeze", Context{Kind: SourceVK, Subtype: SubtypeIOS}},
+		{"method segment not attached", Context{Kind: SourceTelegram}},
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			_, err := gateOnlyService().CreateOrder(ctx, acc, tc.cxt, present, prod, "robokassa")
+			if !errors.Is(err, ErrUntrusted) {
+				t.Fatalf("CreateOrder(%s) = %v, want ErrUntrusted", tc.name, err)
+			}
+		})
+	}
+}

backend/internal/payments/store_intake.go

@@ -0,0 +1,381 @@
+package payments
+
+import (
+	"context"
+	"database/sql"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"time"
+
+	"github.com/go-jet/jet/v2/postgres"
+	"github.com/go-jet/jet/v2/qrm"
+	"github.com/google/uuid"
+	"github.com/jackc/pgx/v5/pgconn"
+
+	"scrabble/backend/internal/postgres/jet/payments/model"
+	"scrabble/backend/internal/postgres/jet/payments/table"
+)
+
+// Intake errors surfaced by the order-flow and external-credit (fund) path.
+var (
+	// ErrNotAPack means the product is not a fundable chip pack in the requested method: it
+	// carries no chips atom, or no price for that payment method.
+	ErrNotAPack = errors.New("payments: product is not a chip pack for this method")
+	// ErrOrderNotFound means no order matches the id (an unknown or forged callback reference).
+	ErrOrderNotFound = errors.New("payments: order not found")
+	// ErrAmountMismatch means the callback's paid amount or currency does not match the order's
+	// expected amount — the credit is refused (§9: verify amount after matching by order id).
+	ErrAmountMismatch = errors.New("payments: paid amount does not match the order")
+)
+
+// errAlreadyCredited is the internal sentinel that unwinds the fund transaction when the ledger's
+// (provider, provider_payment_id) unique index rejects a duplicate callback. It is not surfaced:
+// a replayed callback is a success that credits nothing.
+var errAlreadyCredited = errors.New("payments: already credited")
+
+// packInfo is a chip pack resolved for an order: the product, the chips it funds and its price in
+// the requested payment method's currency.
+type packInfo struct {
+	productID uuid.UUID
+	title     string
+	chips     int
+	price     Money
+}
+
+// packChips returns the quantity of the chips atom a product carries, or 0 if it has none (which
+// marks it as a value, not a fundable pack).
+func (s *Store) packChips(ctx context.Context, productID uuid.UUID) (int, error) {
+	var item model.ProductItem
+	err := postgres.SELECT(table.ProductItem.AllColumns).
+		FROM(table.ProductItem).
+		WHERE(table.ProductItem.ProductID.EQ(postgres.UUID(productID)).
+			AND(table.ProductItem.AtomType.EQ(postgres.String(atomChips)))).
+		LIMIT(1).
+		QueryContext(ctx, s.db, &item)
+	if errors.Is(err, qrm.ErrNoRows) {
+		return 0, nil
+	}
+	if err != nil {
+		return 0, fmt.Errorf("payments: load pack chips %s: %w", productID, err)
+	}
+	return int(item.Quantity), nil
+}
+
+// loadPackForOrder resolves an active chip pack for a new order in the given payment method: an
+// active product carrying a chips atom and a price row for the method (its currency and amount are
+// the order's expected amount). It rejects a missing/deactivated product (ErrProductNotFound) and
+// a product that is not a pack for the method (ErrNotAPack).
+func (s *Store) loadPackForOrder(ctx context.Context, productID uuid.UUID, method Source) (packInfo, error) {
+	var p model.Product
+	err := postgres.SELECT(table.Product.AllColumns).
+		FROM(table.Product).
+		WHERE(table.Product.ProductID.EQ(postgres.UUID(productID))).
+		LIMIT(1).
+		QueryContext(ctx, s.db, &p)
+	if errors.Is(err, qrm.ErrNoRows) || (err == nil && !p.Active) {
+		return packInfo{}, ErrProductNotFound
+	}
+	if err != nil {
+		return packInfo{}, fmt.Errorf("payments: load product %s: %w", productID, err)
+	}
+
+	chips, err := s.packChips(ctx, productID)
+	if err != nil {
+		return packInfo{}, err
+	}
+	if chips <= 0 {
+		return packInfo{}, ErrNotAPack
+	}
+
+	var price model.ProductPrice
+	err = postgres.SELECT(table.ProductPrice.AllColumns).
+		FROM(table.ProductPrice).
+		WHERE(table.ProductPrice.ProductID.EQ(postgres.UUID(productID)).
+			AND(table.ProductPrice.Method.EQ(postgres.String(string(method))))).
+		LIMIT(1).
+		QueryContext(ctx, s.db, &price)
+	if errors.Is(err, qrm.ErrNoRows) {
+		return packInfo{}, ErrNotAPack
+	}
+	if err != nil {
+		return packInfo{}, fmt.Errorf("payments: load pack price %s: %w", productID, err)
+	}
+	money, err := MoneyFromMinor(price.Amount, Currency(price.Currency))
+	if err != nil {
+		return packInfo{}, err
+	}
+	return packInfo{productID: productID, title: p.Title, chips: chips, price: money}, nil
+}
+
+// packForCredit resolves the chips and title of an ordered pack at credit time, ignoring the
+// product's active flag: the money is real, so an order is honoured even if the pack was
+// deactivated after it was placed (§9/D23).
+func (s *Store) packForCredit(ctx context.Context, productID uuid.UUID) (chips int, title string, err error) {
+	var p model.Product
+	e := postgres.SELECT(table.Product.Title).
+		FROM(table.Product).
+		WHERE(table.Product.ProductID.EQ(postgres.UUID(productID))).
+		LIMIT(1).
+		QueryContext(ctx, s.db, &p)
+	if errors.Is(e, qrm.ErrNoRows) {
+		return 0, "", ErrProductNotFound
+	}
+	if e != nil {
+		return 0, "", fmt.Errorf("payments: load product %s: %w", productID, e)
+	}
+	chips, err = s.packChips(ctx, productID)
+	if err != nil {
+		return 0, "", err
+	}
+	if chips <= 0 {
+		return 0, "", ErrNotAPack
+	}
+	return chips, p.Title, nil
+}
+
+// newOrder is the intent a CreateOrder writes: a pending order for a pack, priced in the method's
+// currency, tagged with the provider that will settle it.
+type newOrder struct {
+	orderID   uuid.UUID
+	accountID uuid.UUID
+	platform  string
+	productID uuid.UUID
+	amount    Money
+	origin    Source
+	provider  string
+}
+
+// createOrder inserts a pending order.
+func (s *Store) createOrder(ctx context.Context, o newOrder, now time.Time) error {
+	stmt := table.Orders.INSERT(
+		table.Orders.OrderID, table.Orders.AccountID, table.Orders.Platform,
+		table.Orders.ProductID, table.Orders.ExpectedAmount, table.Orders.Currency,
+		table.Orders.Origin, table.Orders.Status, table.Orders.Provider,
+		table.Orders.CreatedAt, table.Orders.UpdatedAt,
+	).VALUES(
+		o.orderID, o.accountID, o.platform,
+		o.productID, o.amount.Minor(), string(o.amount.Currency()),
+		string(o.origin), "pending", o.provider,
+		now, now,
+	)
+	if _, err := stmt.ExecContext(ctx, s.db); err != nil {
+		return fmt.Errorf("payments: create order: %w", err)
+	}
+	return nil
+}
+
+// orderRow is a stored order read back for the intake path.
+type orderRow struct {
+	orderID        uuid.UUID
+	accountID      uuid.UUID
+	productID      uuid.UUID
+	expectedAmount int64
+	currency       string
+	origin         string
+	status         string
+}
+
+// orderByID reads an order, or ErrOrderNotFound.
+func (s *Store) orderByID(ctx context.Context, orderID uuid.UUID) (orderRow, error) {
+	var o model.Orders
+	err := postgres.SELECT(table.Orders.AllColumns).
+		FROM(table.Orders).
+		WHERE(table.Orders.OrderID.EQ(postgres.UUID(orderID))).
+		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 %s: %w", orderID, err)
+	}
+	return orderRow{
+		orderID:        o.OrderID,
+		accountID:      o.AccountID,
+		productID:      o.ProductID,
+		expectedAmount: o.ExpectedAmount,
+		currency:       o.Currency,
+		origin:         o.Origin,
+		status:         o.Status,
+	}, nil
+}
+
+// FundOutcome reports the result of an intake credit: whose balance, which segment and how many
+// chips were credited, and whether the callback was a duplicate that credited nothing.
+type FundOutcome struct {
+	AccountID       uuid.UUID
+	Source          Source
+	Chips           int
+	AlreadyCredited bool
+}
+
+// fund credits a paid order exactly once: it matches the order, verifies the amount, then in one
+// transaction appends a fund ledger row (idempotent on the (provider, provider_payment_id) unique
+// index), credits the funded segment's balance and marks the order paid. A duplicate callback is
+// rejected by the unique index and returns AlreadyCredited with no error and no second credit. A
+// valid callback is honoured even on an expired order (§9/D23). The read cache is invalidated after
+// the commit, since the credit runs outside any request the payments package owns.
+func (s *Store) fund(ctx context.Context, orderID uuid.UUID, provider, providerPaymentID string, paid Money, now time.Time) (FundOutcome, error) {
+	ord, err := s.orderByID(ctx, orderID)
+	if err != nil {
+		return FundOutcome{}, err
+	}
+	if paid.Currency() != Currency(ord.currency) || paid.Minor() != ord.expectedAmount {
+		return FundOutcome{}, ErrAmountMismatch
+	}
+	chips, title, err := s.packForCredit(ctx, ord.productID)
+	if err != nil {
+		return FundOutcome{}, err
+	}
+	snapshot, err := marshalFundSnapshot(ord.productID, title, chips, paid)
+	if err != nil {
+		return FundOutcome{}, err
+	}
+
+	src := Source(ord.origin)
+	outcome := FundOutcome{AccountID: ord.accountID, Source: src, Chips: chips}
+	pv, pp := provider, providerPaymentID
+	productID := ord.productID
+	err = withTx(ctx, s.db, func(tx *sql.Tx) error {
+		if e := insertLedgerTx(ctx, tx, ord.accountID, "fund", &src, &src, chips, &productID, &orderID, &pv, &pp, snapshot, now); e != nil {
+			if isUniqueViolation(e) {
+				outcome.AlreadyCredited = true
+				return errAlreadyCredited
+			}
+			return e
+		}
+		if _, e := tx.ExecContext(ctx,
+			`INSERT INTO payments.balances (account_id, source, chips, updated_at)
+			 VALUES ($1, $2, $3, now())
+			 ON CONFLICT (account_id, source) DO UPDATE
+			   SET chips = payments.balances.chips + EXCLUDED.chips, updated_at = now()`,
+			ord.accountID, string(src), chips); e != nil {
+			return fmt.Errorf("payments: credit balance %s: %w", src, e)
+		}
+		if _, e := tx.ExecContext(ctx,
+			`UPDATE payments.orders SET status = 'paid', provider = $2, provider_payment_id = $3, updated_at = now()
+			 WHERE order_id = $1`,
+			orderID, provider, providerPaymentID); e != nil {
+			return fmt.Errorf("payments: mark order paid: %w", e)
+		}
+		return nil
+	})
+	if err != nil {
+		if errors.Is(err, errAlreadyCredited) {
+			return outcome, nil
+		}
+		return FundOutcome{}, err
+	}
+	s.cache.invalidate(ord.accountID)
+	return outcome, nil
+}
+
+// insertPaymentEvent appends an undispatched lifecycle event (succeeded/failed/refunded) for the
+// dispatcher to deliver. orderID and payload (a jsonb detail blob) are optional.
+func (s *Store) insertPaymentEvent(ctx context.Context, accountID uuid.UUID, orderID *uuid.UUID, eventType string, payload []byte, now time.Time) error {
+	id, err := uuid.NewV7()
+	if err != nil {
+		return fmt.Errorf("payments: event id: %w", err)
+	}
+	var pl any = postgres.NULL
+	if payload != nil {
+		pl = string(payload)
+	}
+	stmt := table.PaymentEvents.INSERT(
+		table.PaymentEvents.EventID, table.PaymentEvents.AccountID, table.PaymentEvents.OrderID,
+		table.PaymentEvents.Type, table.PaymentEvents.Payload, table.PaymentEvents.CreatedAt,
+	).VALUES(id, accountID, uuidOrNull(orderID), eventType, pl, now)
+	if _, err := stmt.ExecContext(ctx, s.db); err != nil {
+		return fmt.Errorf("payments: insert %s event: %w", eventType, err)
+	}
+	return nil
+}
+
+// PaymentEvent is an undispatched lifecycle event the dispatcher delivers to an account.
+type PaymentEvent struct {
+	EventID   uuid.UUID
+	AccountID uuid.UUID
+	Type      string
+}
+
+// undispatchedEvents reads up to limit payment events not yet delivered, oldest first.
+func (s *Store) undispatchedEvents(ctx context.Context, limit int) ([]PaymentEvent, error) {
+	rows, err := s.db.QueryContext(ctx,
+		`SELECT event_id, account_id, type FROM payments.payment_events
+		 WHERE dispatched_at IS NULL ORDER BY created_at LIMIT $1`, limit)
+	if err != nil {
+		return nil, fmt.Errorf("payments: read undispatched events: %w", err)
+	}
+	defer rows.Close()
+	var out []PaymentEvent
+	for rows.Next() {
+		var e PaymentEvent
+		if err := rows.Scan(&e.EventID, &e.AccountID, &e.Type); err != nil {
+			return nil, fmt.Errorf("payments: scan event: %w", err)
+		}
+		out = append(out, e)
+	}
+	return out, rows.Err()
+}
+
+// markEventDispatched stamps an event as delivered so it is not re-sent.
+func (s *Store) markEventDispatched(ctx context.Context, eventID uuid.UUID, now time.Time) error {
+	if _, err := s.db.ExecContext(ctx,
+		`UPDATE payments.payment_events SET dispatched_at = $2 WHERE event_id = $1`, eventID, now); err != nil {
+		return fmt.Errorf("payments: mark event dispatched: %w", err)
+	}
+	return nil
+}
+
+// orderTTL reads the configured pending-order lifetime in whole seconds.
+func (s *Store) orderTTL(ctx context.Context) (int, error) {
+	var cfg model.Config
+	if err := postgres.SELECT(table.Config.OrderTTLSeconds).
+		FROM(table.Config).
+		LIMIT(1).
+		QueryContext(ctx, s.db, &cfg); err != nil {
+		return 0, fmt.Errorf("payments: read order ttl: %w", err)
+	}
+	return int(cfg.OrderTTLSeconds), nil
+}
+
+// expirePending marks every pending order older than ttlSeconds as expired, returning how many.
+// Expiry is cosmetic DB hygiene: a later valid callback still credits an expired order (§9/D23).
+func (s *Store) expirePending(ctx context.Context, ttlSeconds int, now time.Time) (int, error) {
+	cutoff := now.Add(-time.Duration(ttlSeconds) * time.Second)
+	res, err := table.Orders.
+		UPDATE(table.Orders.Status, table.Orders.UpdatedAt).
+		SET(postgres.String("expired"), postgres.TimestampzT(now)).
+		WHERE(table.Orders.Status.EQ(postgres.String("pending")).
+			AND(table.Orders.CreatedAt.LT(postgres.TimestampzT(cutoff)))).
+		ExecContext(ctx, s.db)
+	if err != nil {
+		return 0, fmt.Errorf("payments: expire pending orders: %w", err)
+	}
+	n, _ := res.RowsAffected()
+	return int(n), nil
+}
+
+// marshalFundSnapshot records what a fund credited (the pack, chips and paid amount) on the ledger
+// row, so history stays independent of later catalog edits (§7/D34).
+func marshalFundSnapshot(productID uuid.UUID, title string, chips int, paid Money) ([]byte, error) {
+	b, err := json.Marshal(struct {
+		ProductID string `json:"product_id"`
+		Title     string `json:"title,omitempty"`
+		Chips     int    `json:"chips"`
+		Amount    int64  `json:"amount_minor"`
+		Currency  string `json:"currency"`
+	}{productID.String(), title, chips, paid.Minor(), string(paid.Currency())})
+	if err != nil {
+		return nil, fmt.Errorf("payments: marshal fund snapshot: %w", err)
+	}
+	return b, nil
+}
+
+// isUniqueViolation reports whether err is a PostgreSQL unique-constraint violation (SQLSTATE
+// 23505) — here, a duplicate provider callback hitting the ledger idempotency index.
+func isUniqueViolation(err error) bool {
+	var pgErr *pgconn.PgError
+	return errors.As(err, &pgErr) && pgErr.Code == "23505"
+}

backend/internal/payments/store_wallet.go

@@ -230,8 +230,11 @@ func applyBenefitTx(ctx context.Context, tx *sql.Tx, accountID uuid.UUID, origin
 	return nil
 }
 
-// insertLedgerTx appends one append-only ledger row inside tx.
+// insertLedgerTx appends one append-only ledger row inside tx. orderID, provider and
-func insertLedgerTx(ctx context.Context, tx *sql.Tx, accountID uuid.UUID, kind string, source, origin *Source, chipsDelta int, productID *uuid.UUID, snapshot []byte, now time.Time) error {
+// providerPaymentID are set only on an intake credit (fund/refund) and are nil for a
+// spend/admin_grant; a non-nil (provider, providerPaymentID) pair is guarded by the partial
+// unique index, so a duplicate provider callback fails here (the idempotency key).
+func insertLedgerTx(ctx context.Context, tx *sql.Tx, accountID uuid.UUID, kind string, source, origin *Source, chipsDelta int, productID, orderID *uuid.UUID, provider, providerPaymentID *string, snapshot []byte, now time.Time) error {
 	id, err := uuid.NewV7()
 	if err != nil {
 		return fmt.Errorf("payments: ledger id: %w", err)
@@ -246,11 +249,13 @@ func insertLedgerTx(ctx context.Context, tx *sql.Tx, accountID uuid.UUID, kind s
 	stmt := table.Ledger.INSERT(
 		table.Ledger.LedgerID, table.Ledger.AccountID, table.Ledger.Kind,
 		table.Ledger.Source, table.Ledger.Origin, table.Ledger.ChipsDelta,
-		table.Ledger.ProductID, table.Ledger.Snapshot, table.Ledger.CreatedAt,
+		table.Ledger.ProductID, table.Ledger.OrderID, table.Ledger.Provider,
+		table.Ledger.ProviderPaymentID, table.Ledger.Snapshot, table.Ledger.CreatedAt,
 	).VALUES(
 		id, accountID, kind,
 		sourceOrNull(source), sourceOrNull(origin), int32(chipsDelta),
-		uuidOrNull(productID), snap, now,
+		uuidOrNull(productID), uuidOrNull(orderID), stringOrNull(provider),
+		stringOrNull(providerPaymentID), snap, now,
 	)
 	if _, err := stmt.ExecContext(ctx, tx); err != nil {
 		return fmt.Errorf("payments: insert %s ledger: %w", kind, err)
@@ -278,7 +283,7 @@ func (s *Store) spend(ctx context.Context, accountID uuid.UUID, draws []sourceAm
 				return ErrInsufficientChips
 			}
 			src := dr.source
-			if err := insertLedgerTx(ctx, tx, accountID, "spend", &src, &origin, -dr.amount, &productID, snapshot, now); err != nil {
+			if err := insertLedgerTx(ctx, tx, accountID, "spend", &src, &origin, -dr.amount, &productID, nil, nil, nil, snapshot, now); err != nil {
 				return err
 			}
 		}
@@ -295,7 +300,7 @@ func (s *Store) spend(ctx context.Context, accountID uuid.UUID, draws []sourceAm
 // the chosen origin, in one transaction — a zero-price sale of a value.
 func (s *Store) grant(ctx context.Context, accountID uuid.UUID, origin Source, d benefitDelta, snapshot []byte, now time.Time) error {
 	err := withTx(ctx, s.db, func(tx *sql.Tx) error {
-		if err := insertLedgerTx(ctx, tx, accountID, "admin_grant", nil, &origin, 0, nil, snapshot, now); err != nil {
+		if err := insertLedgerTx(ctx, tx, accountID, "admin_grant", nil, &origin, 0, nil, nil, nil, nil, snapshot, now); err != nil {
 			return err
 		}
 		return applyBenefitTx(ctx, tx, accountID, origin, d, now)
@@ -419,3 +424,11 @@ func uuidOrNull(id *uuid.UUID) postgres.Expression {
 	}
 	return postgres.UUID(*id)
 }
+
+// stringOrNull renders an optional string as a SQL string or NULL.
+func stringOrNull(s *string) postgres.Expression {
+	if s == nil {
+		return postgres.NULL
+	}
+	return postgres.String(*s)
+}

backend/internal/robokassa/robokassa.go

@@ -0,0 +1,104 @@
+// Package robokassa builds and verifies Robokassa direct-rail (RUB) payments: it forms the signed
+// hosted-payment URL a client is sent to, and verifies the Result-URL server callback that credits
+// an order. It is pure provider glue — no database, no payments-domain coupling — so the payments
+// domain stays provider-agnostic and this layer is unit-testable in isolation.
+//
+// The order is threaded through Robokassa's custom-parameter channel as Shp_order=<order id> (echoed
+// back in the callback and bound into the signature), not the numeric InvId, because an order id is
+// a uuid; InvId is sent as 0. Idempotency is therefore keyed on the order id at the credit site.
+// Signatures use SHA-256 (configured to match the shop's technical settings); the shop's test mode
+// is carried by IsTest.
+package robokassa
+
+import (
+	"crypto/sha256"
+	"encoding/hex"
+	"net/url"
+	"sort"
+	"strings"
+
+	"github.com/google/uuid"
+)
+
+// payEndpoint is Robokassa's hosted payment page; the signed query sends the client there.
+const payEndpoint = "https://auth.robokassa.ru/Merchant/Index.aspx"
+
+// Config is a Robokassa shop's credentials. Password1 signs the outgoing payment request;
+// Password2 signs (and so verifies) the incoming Result callback. IsTest adds IsTest=1 so the shop's
+// test mode simulates payments without money movement.
+type Config struct {
+	MerchantLogin string
+	Password1     string
+	Password2     string
+	IsTest        bool
+}
+
+// PaymentURL builds the signed hosted-payment URL for an order: amount is the OutSum decimal string
+// (roubles, e.g. "149.00"), description is the human payment purpose. The order id rides as
+// Shp_order and is bound into the SHA-256 signature; InvId is 0 (unused).
+func (c Config) PaymentURL(orderID uuid.UUID, amount, description string) string {
+	q := url.Values{}
+	q.Set("Shp_order", orderID.String())
+	// Signature base: MerchantLogin:OutSum:InvId:Password1[:Shp_key=value...sorted].
+	base := c.MerchantLogin + ":" + amount + ":0:" + c.Password1 + shpSuffix(q)
+
+	q.Set("MerchantLogin", c.MerchantLogin)
+	q.Set("OutSum", amount)
+	q.Set("InvId", "0")
+	q.Set("Description", description)
+	q.Set("SignatureValue", sign(base))
+	if c.IsTest {
+		q.Set("IsTest", "1")
+	}
+	return payEndpoint + "?" + q.Encode()
+}
+
+// VerifyResult verifies a Result-URL callback and extracts the order it credits. It recomputes the
+// SHA-256 signature OutSum:InvId:Password2[:Shp_...sorted] over the callback's own fields and
+// compares it (case-insensitively) with SignatureValue. On success it returns the order id (from
+// Shp_order) and the raw OutSum string the caller re-checks against the order amount; on any
+// missing field, a signature mismatch or an unparseable order id it returns ok=false.
+func (c Config) VerifyResult(v url.Values) (orderID uuid.UUID, outSum string, ok bool) {
+	outSum = v.Get("OutSum")
+	sig := v.Get("SignatureValue")
+	order := v.Get("Shp_order")
+	if outSum == "" || sig == "" || order == "" {
+		return uuid.Nil, "", false
+	}
+	// Robokassa signs with the InvId it returns in the callback; recompute with that same value.
+	base := outSum + ":" + v.Get("InvId") + ":" + c.Password2 + shpSuffix(v)
+	if !strings.EqualFold(sign(base), sig) {
+		return uuid.Nil, "", false
+	}
+	id, err := uuid.Parse(order)
+	if err != nil {
+		return uuid.Nil, "", false
+	}
+	return id, outSum, true
+}
+
+// shpSuffix renders the Shp_ custom parameters of v as Robokassa binds them into a signature:
+// every Shp_-prefixed key, sorted alphabetically, appended as ":key=value".
+func shpSuffix(v url.Values) string {
+	var keys []string
+	for k := range v {
+		if strings.HasPrefix(k, "Shp_") {
+			keys = append(keys, k)
+		}
+	}
+	sort.Strings(keys)
+	var b strings.Builder
+	for _, k := range keys {
+		b.WriteString(":")
+		b.WriteString(k)
+		b.WriteString("=")
+		b.WriteString(v.Get(k))
+	}
+	return b.String()
+}
+
+// sign returns the lowercase hex SHA-256 of s, the hash Robokassa compares against SignatureValue.
+func sign(s string) string {
+	sum := sha256.Sum256([]byte(s))
+	return hex.EncodeToString(sum[:])
+}

backend/internal/robokassa/robokassa_test.go

@@ -0,0 +1,85 @@
+package robokassa
+
+import (
+	"net/url"
+	"strings"
+	"testing"
+
+	"github.com/google/uuid"
+)
+
+func testCfg() Config {
+	return Config{MerchantLogin: "shop", Password1: "p1", Password2: "p2", IsTest: true}
+}
+
+// resultSig computes the Pass2 Result signature Robokassa would send for a callback carrying only
+// Shp_order — the fixture the verifier must accept.
+func resultSig(pass2, outSum, invID string, orderID uuid.UUID) string {
+	return sign(outSum + ":" + invID + ":" + pass2 + ":Shp_order=" + orderID.String())
+}
+
+func TestPaymentURL(t *testing.T) {
+	cfg := testCfg()
+	id := uuid.New()
+	u, err := url.Parse(cfg.PaymentURL(id, "149.00", "10 chips"))
+	if err != nil {
+		t.Fatalf("parse payment url: %v", err)
+	}
+	q := u.Query()
+	if got := q.Get("OutSum"); got != "149.00" {
+		t.Errorf("OutSum = %q, want 149.00", got)
+	}
+	if got := q.Get("InvId"); got != "0" {
+		t.Errorf("InvId = %q, want 0 (unused)", got)
+	}
+	if got := q.Get("Shp_order"); got != id.String() {
+		t.Errorf("Shp_order = %q, want the order id", got)
+	}
+	if got := q.Get("IsTest"); got != "1" {
+		t.Errorf("IsTest = %q, want 1 (test shop)", got)
+	}
+	want := sign("shop:149.00:0:p1:Shp_order=" + id.String())
+	if got := q.Get("SignatureValue"); got != want {
+		t.Errorf("SignatureValue = %q, want %q", got, want)
+	}
+}
+
+func TestVerifyResult(t *testing.T) {
+	cfg := testCfg()
+	id := uuid.New()
+
+	valid := func() url.Values {
+		v := url.Values{}
+		v.Set("OutSum", "149.00")
+		v.Set("InvId", "0")
+		v.Set("Shp_order", id.String())
+		// Robokassa sends the hash uppercase; the verifier must be case-insensitive.
+		v.Set("SignatureValue", strings.ToUpper(resultSig("p2", "149.00", "0", id)))
+		return v
+	}
+
+	gotID, gotSum, ok := cfg.VerifyResult(valid())
+	if !ok || gotID != id || gotSum != "149.00" {
+		t.Fatalf("VerifyResult(valid) = %v/%q/%v, want %v/149.00/true", gotID, gotSum, ok, id)
+	}
+
+	// A tampered amount breaks the signature.
+	tampered := valid()
+	tampered.Set("OutSum", "1.00")
+	if _, _, ok := cfg.VerifyResult(tampered); ok {
+		t.Error("VerifyResult accepted a tampered amount")
+	}
+
+	// The wrong Password2 (a forged callback) does not verify.
+	wrongPass := Config{MerchantLogin: "shop", Password1: "p1", Password2: "other"}
+	if _, _, ok := wrongPass.VerifyResult(valid()); ok {
+		t.Error("VerifyResult accepted a signature under the wrong password")
+	}
+
+	// A missing Shp_order is rejected (no order to credit).
+	noOrder := valid()
+	noOrder.Del("Shp_order")
+	if _, _, ok := cfg.VerifyResult(noOrder); ok {
+		t.Error("VerifyResult accepted a callback with no order")
+	}
+}

backend/internal/server/handlers.go

@@ -73,6 +73,21 @@ func (s *Server) registerRoutes() {
 		u.GET("/wallet/catalog", s.handleWalletCatalog)
 		u.POST("/wallet/buy", s.handleWalletBuy)
 	}
+	if s.payments != nil {
+		// The money order endpoint dispatches by rail (direct → Robokassa, vk → VK); an
+		// unsupported or unconfigured rail returns 501 from the handler. The provider callbacks are
+		// gateway-only (the single writer): the VK payment callback (both phases handled here), and
+		// the Robokassa Result callback when a merchant is configured.
+		u.POST("/wallet/order", s.handleWalletOrder)
+		s.internal.POST("/payments/vk/callback", s.handleVKCallback)
+		// The Telegram Stars rail: the bot forwards a pre_checkout validation and a completed
+		// payment over the reverse bot-link; the gateway proxies both onto these gateway-only routes.
+		s.internal.POST("/payments/telegram/precheckout", s.handleTelegramPreCheckout)
+		s.internal.POST("/payments/telegram/payment", s.handleTelegramPayment)
+		if s.robokassa.MerchantLogin != "" {
+			s.internal.POST("/payments/robokassa/result", s.handleRobokassaResult)
+		}
+	}
 	if s.links != nil {
 		// Account linking & merge. The request step always mails a code;
 		// a required merge is revealed only after the code is verified, and the
@@ -266,6 +281,8 @@ func statusForError(err error) (int, string) {
 		return http.StatusNotFound, "product_not_found"
 	case errors.Is(err, payments.ErrNotAValue):
 		return http.StatusBadRequest, "not_a_value"
+	case errors.Is(err, payments.ErrNotAPack):
+		return http.StatusBadRequest, "not_a_pack"
 	case errors.Is(err, account.ErrInvalidEmail):
 		return http.StatusBadRequest, "invalid_email"
 	case errors.Is(err, account.ErrCodeMismatch), errors.Is(err, account.ErrCodeExpired),

backend/internal/server/handlers_intake.go

@@ -0,0 +1,399 @@
+package server
+
+import (
+	"encoding/json"
+	"errors"
+	"net/http"
+	"net/url"
+	"strconv"
+
+	"github.com/gin-gonic/gin"
+	"github.com/google/uuid"
+	"go.uber.org/zap"
+
+	"scrabble/backend/internal/payments"
+)
+
+// Ledger/order provider tags per rail.
+const (
+	providerRobokassa = "robokassa" // the direct (RUB) rail
+	providerVK        = "vk"        // the VK Votes rail
+	providerTelegram  = "telegram"  // the Telegram Stars (XTR) rail
+)
+
+// walletOrderRequest is the POST body of a chip-pack purchase: the pack to fund.
+type walletOrderRequest struct {
+	ProductID string `json:"product_id"`
+}
+
+// walletOrderResponse returns the created order id and the rail's launch details. RedirectURL is
+// the provider's hosted-payment URL for the direct rail (empty for VK/Telegram, which settle
+// in-app). Rail names the settling rail so the gateway knows how to launch it; for the Telegram
+// Stars rail the gateway mints the invoice link from InvoiceTitle and InvoiceAmount (whole stars)
+// via the bot and returns it in RedirectURL.
+type walletOrderResponse struct {
+	OrderID       string `json:"order_id"`
+	RedirectURL   string `json:"redirect_url"`
+	Rail          string `json:"rail"`
+	InvoiceTitle  string `json:"invoice_title,omitempty"`
+	InvoiceAmount int64  `json:"invoice_amount,omitempty"`
+}
+
+// handleWalletOrder opens a pending order to fund a chip pack and returns the rail's launch
+// details for the client: the Robokassa hosted-payment URL (direct), the order id for
+// VKWebAppShowOrderBox (VK), or the pack title and star amount the gateway mints into a Stars
+// invoice link (Telegram). It enforces the wallet gate and, on the direct rail, D36 (a purchase
+// requires a confirmed email anchor). No chips are credited here — only later, by the verified
+// provider callback.
+func (s *Server) handleWalletOrder(c *gin.Context) {
+	uid, ok := userID(c)
+	if !ok {
+		return
+	}
+	var req walletOrderRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		c.AbortWithStatusJSON(http.StatusBadRequest, errorResponse{Error: errorBody{Code: "invalid_request", Message: "invalid request body"}})
+		return
+	}
+	productID, err := uuid.Parse(req.ProductID)
+	if err != nil {
+		c.AbortWithStatusJSON(http.StatusBadRequest, errorResponse{Error: errorBody{Code: "invalid_request", Message: "invalid product id"}})
+		return
+	}
+	ctx := c.Request.Context()
+	cxt, present, err := s.walletGate(ctx, uid)
+	if err != nil {
+		s.abortErr(c, err)
+		return
+	}
+	switch cxt.Kind {
+	case payments.SourceDirect:
+		if s.robokassa.MerchantLogin == "" {
+			c.AbortWithStatusJSON(http.StatusNotImplemented, errorResponse{Error: errorBody{Code: "rail_unavailable", Message: "this payment method is not available"}})
+			return
+		}
+		// D36: a direct purchase requires a confirmed email anchor.
+		hasEmail, err := s.accounts.HasConfirmedEmail(ctx, uid)
+		if err != nil {
+			s.abortErr(c, err)
+			return
+		}
+		if !hasEmail {
+			c.AbortWithStatusJSON(http.StatusForbidden, errorResponse{Error: errorBody{Code: "email_required", Message: "confirm your email before making a purchase"}})
+			return
+		}
+		res, err := s.payments.CreateOrder(ctx, uid, cxt, present, productID, providerRobokassa)
+		if err != nil {
+			s.abortErr(c, err)
+			return
+		}
+		c.JSON(http.StatusOK, walletOrderResponse{
+			OrderID:     res.OrderID.String(),
+			RedirectURL: s.robokassa.PaymentURL(res.OrderID, res.Amount.Major(), res.Title),
+			Rail:        providerRobokassa,
+		})
+	case payments.SourceVK:
+		res, err := s.payments.CreateOrder(ctx, uid, cxt, present, productID, providerVK)
+		if err != nil {
+			s.abortErr(c, err)
+			return
+		}
+		// The client passes the order id to VKWebAppShowOrderBox as the item; there is no redirect.
+		c.JSON(http.StatusOK, walletOrderResponse{OrderID: res.OrderID.String(), Rail: providerVK})
+	case payments.SourceTelegram:
+		res, err := s.payments.CreateOrder(ctx, uid, cxt, present, productID, providerTelegram)
+		if err != nil {
+			s.abortErr(c, err)
+			return
+		}
+		// The gateway mints the Stars invoice link from the title and amount via the bot (only
+		// the bot reaches Telegram) and returns it to the client as RedirectURL; the amount is in
+		// whole stars (the XTR minor unit is the star). No chips are credited until the verified
+		// successful_payment is forwarded back through the bot.
+		c.JSON(http.StatusOK, walletOrderResponse{
+			OrderID:       res.OrderID.String(),
+			Rail:          providerTelegram,
+			InvoiceTitle:  res.Title,
+			InvoiceAmount: res.Amount.Minor(),
+		})
+	default:
+		c.AbortWithStatusJSON(http.StatusNotImplemented, errorResponse{Error: errorBody{Code: "rail_unavailable", Message: "this payment method is not available yet"}})
+	}
+}
+
+// handleRobokassaResult is the verified Robokassa Result callback, reached only through the gateway
+// (which forwards the provider's form parameters as a JSON object on the internal, gateway-only
+// route). It verifies the Password2 signature, credits the matched order exactly once (idempotent,
+// and honoured even if the order expired), records a succeeded event, and answers Robokassa's
+// expected "OK<InvId>". A duplicate callback credits nothing but still answers OK.
+func (s *Server) handleRobokassaResult(c *gin.Context) {
+	var params map[string]string
+	if err := c.ShouldBindJSON(&params); err != nil {
+		c.String(http.StatusBadRequest, "bad request")
+		return
+	}
+	v := url.Values{}
+	for k, val := range params {
+		v.Set(k, val)
+	}
+	orderID, outSum, ok := s.robokassa.VerifyResult(v)
+	if !ok {
+		s.log.Warn("robokassa result: bad signature")
+		c.String(http.StatusBadRequest, "bad sign")
+		return
+	}
+	paid, err := payments.ParseMoney(outSum, payments.CurrencyRUB)
+	if err != nil {
+		c.String(http.StatusBadRequest, "bad amount")
+		return
+	}
+	ctx := c.Request.Context()
+	outcome, err := s.payments.Fund(ctx, orderID, providerRobokassa, orderID.String(), paid)
+	if err != nil {
+		if errors.Is(err, payments.ErrOrderNotFound) || errors.Is(err, payments.ErrAmountMismatch) ||
+			errors.Is(err, payments.ErrNotAPack) || errors.Is(err, payments.ErrProductNotFound) {
+			s.log.Warn("robokassa result rejected", zap.String("order", orderID.String()), zap.Error(err))
+			c.String(http.StatusBadRequest, "rejected")
+			return
+		}
+		s.log.Error("robokassa fund failed", zap.String("order", orderID.String()), zap.Error(err))
+		c.String(http.StatusInternalServerError, "error")
+		return
+	}
+	if !outcome.AlreadyCredited {
+		payload, _ := json.Marshal(map[string]any{"chips": outcome.Chips, "source": string(outcome.Source)})
+		if err := s.payments.RecordPaymentEvent(ctx, outcome.AccountID, &orderID, "succeeded", payload); err != nil {
+			s.log.Error("record payment event failed", zap.String("order", orderID.String()), zap.Error(err))
+		}
+	}
+	// The gateway echoes response verbatim to Robokassa, which requires the body "OK<InvId>".
+	c.JSON(http.StatusOK, gin.H{"response": "OK" + v.Get("InvId")})
+}
+
+// vkErrorResponse builds VK's error envelope for a payment callback.
+func vkErrorResponse(code int, msg string, critical bool) gin.H {
+	return gin.H{"error": gin.H{"error_code": code, "error_msg": msg, "critical": critical}}
+}
+
+// handleVKCallback is the VK Mini Apps payment callback, reached only through the gateway (which
+// verifies the VK signature and forwards the provider's parameters as a JSON object on the internal
+// route). It answers VK's two phases: get_item returns the ordered pack's title and vote price; a
+// chargeable order_status_change credits the matched order exactly once (idempotent on VK's order
+// id) and records a succeeded event. Both phases use VK's response envelope; the _test variants are
+// the sandbox notifications and are handled identically.
+func (s *Server) handleVKCallback(c *gin.Context) {
+	var params map[string]string
+	if err := c.ShouldBindJSON(&params); err != nil {
+		c.JSON(http.StatusOK, vkErrorResponse(1, "bad request", true))
+		return
+	}
+	ctx := c.Request.Context()
+	switch params["notification_type"] {
+	case "get_item", "get_item_test":
+		orderID, err := uuid.Parse(params["item"])
+		if err != nil {
+			c.JSON(http.StatusOK, vkErrorResponse(20, "item not available", true))
+			return
+		}
+		title, amount, err := s.payments.OrderItem(ctx, orderID)
+		if err != nil {
+			s.log.Warn("vk get_item lookup failed", zap.String("order", orderID.String()), zap.Error(err))
+			c.JSON(http.StatusOK, vkErrorResponse(20, "item not available", true))
+			return
+		}
+		c.JSON(http.StatusOK, gin.H{"response": gin.H{
+			"item_id": orderID.String(),
+			"title":   title,
+			"price":   amount.Minor(),
+		}})
+	case "order_status_change", "order_status_change_test":
+		if params["status"] != "chargeable" {
+			c.JSON(http.StatusOK, vkErrorResponse(100, "unsupported status", false))
+			return
+		}
+		orderID, err := uuid.Parse(params["item"])
+		if err != nil {
+			c.JSON(http.StatusOK, vkErrorResponse(20, "item not available", true))
+			return
+		}
+		price, err := strconv.ParseInt(params["item_price"], 10, 64)
+		if err != nil {
+			c.JSON(http.StatusOK, vkErrorResponse(100, "bad price", false))
+			return
+		}
+		paid, err := payments.MoneyFromMinor(price, payments.CurrencyVote)
+		if err != nil {
+			c.JSON(http.StatusOK, vkErrorResponse(100, "bad price", false))
+			return
+		}
+		vkOrderID := params["order_id"]
+		outcome, err := s.payments.Fund(ctx, orderID, providerVK, vkOrderID, paid)
+		if err != nil {
+			if errors.Is(err, payments.ErrOrderNotFound) || errors.Is(err, payments.ErrAmountMismatch) ||
+				errors.Is(err, payments.ErrNotAPack) || errors.Is(err, payments.ErrProductNotFound) {
+				s.log.Warn("vk order rejected", zap.String("order", orderID.String()), zap.Error(err))
+				c.JSON(http.StatusOK, vkErrorResponse(100, "cannot process the order", false))
+				return
+			}
+			s.log.Error("vk fund failed", zap.String("order", orderID.String()), zap.Error(err))
+			c.JSON(http.StatusOK, vkErrorResponse(100, "internal error", false))
+			return
+		}
+		if !outcome.AlreadyCredited {
+			payload, _ := json.Marshal(map[string]any{"chips": outcome.Chips, "source": string(outcome.Source)})
+			if err := s.payments.RecordPaymentEvent(ctx, outcome.AccountID, &orderID, "succeeded", payload); err != nil {
+				s.log.Error("record vk payment event failed", zap.String("order", orderID.String()), zap.Error(err))
+			}
+		}
+		// Echo VK's own order id; app_order_id is optional and our order id is a uuid, so omit it.
+		appOrderID, _ := strconv.ParseInt(vkOrderID, 10, 64)
+		c.JSON(http.StatusOK, gin.H{"response": gin.H{"order_id": appOrderID}})
+	default:
+		c.JSON(http.StatusOK, vkErrorResponse(100, "unknown notification", false))
+	}
+}
+
+// telegramPreCheckoutRequest is the bot's pre_checkout validation, forwarded through the gateway:
+// the order in the invoice payload and the amount and currency Telegram is about to charge.
+type telegramPreCheckoutRequest struct {
+	OrderID  string `json:"order_id"`
+	Amount   int64  `json:"amount"`
+	Currency string `json:"currency"`
+}
+
+// telegramPreCheckoutResponse tells the bot whether to approve the pre_checkout_query; Reason is a
+// short message the bot surfaces to the payer on a decline.
+type telegramPreCheckoutResponse struct {
+	OK     bool   `json:"ok"`
+	Reason string `json:"reason,omitempty"`
+}
+
+// handleTelegramPreCheckout validates a Telegram Stars pre_checkout_query before the charge,
+// reached only through the gateway (the bot's ValidatePreCheckout, forwarded on the internal
+// route). It approves an order that exists, is not already paid (a reusable invoice link paid twice
+// is refused here, before any star moves) and whose amount and currency match. A malformed
+// reference is a decline, not an error.
+func (s *Server) handleTelegramPreCheckout(c *gin.Context) {
+	var req telegramPreCheckoutRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		abortBadRequest(c, "invalid request body")
+		return
+	}
+	ctx := c.Request.Context()
+	orderID, err := uuid.Parse(req.OrderID)
+	if err != nil {
+		c.JSON(http.StatusOK, telegramPreCheckoutResponse{OK: false, Reason: telegramDeclineText(payments.PreCheckoutGone, "")})
+		return
+	}
+	amount, err := payments.MoneyFromMinor(req.Amount, payments.Currency(req.Currency))
+	if err != nil {
+		c.JSON(http.StatusOK, telegramPreCheckoutResponse{OK: false, Reason: telegramDeclineText(payments.PreCheckoutGone, "")})
+		return
+	}
+	out, err := s.payments.ValidatePreCheckout(ctx, orderID, amount)
+	if err != nil {
+		s.log.Error("telegram pre_checkout validate failed", zap.String("order", orderID.String()), zap.Error(err))
+		c.AbortWithStatusJSON(http.StatusInternalServerError, errorResponse{Error: errorBody{Code: "internal", Message: "internal error"}})
+		return
+	}
+	reason := ""
+	if !out.OK {
+		// Localise the decline to the order account's preferred language (the reason shows in the
+		// Telegram payment sheet). An unknown order has no account, so it falls back to English.
+		lang := ""
+		if s.accounts != nil && out.AccountID != (uuid.UUID{}) {
+			if acc, aerr := s.accounts.GetByID(ctx, out.AccountID); aerr == nil {
+				lang = acc.PreferredLanguage
+			}
+		}
+		reason = telegramDeclineText(out.Reason, lang)
+	}
+	c.JSON(http.StatusOK, telegramPreCheckoutResponse{OK: out.OK, Reason: reason})
+}
+
+// telegramDeclineText renders a pre-checkout decline reason code in the payer's language (ru or
+// anything else falls back to English), for display in the Telegram payment sheet.
+func telegramDeclineText(code, lang string) string {
+	ru := lang == "ru"
+	switch code {
+	case payments.PreCheckoutAlreadyPaid:
+		if ru {
+			return "Этот заказ уже оплачен."
+		}
+		return "This order has already been paid."
+	case payments.PreCheckoutPriceChanged:
+		if ru {
+			return "Цена изменилась — начните покупку заново."
+		}
+		return "The price has changed; please start the purchase again."
+	default:
+		if ru {
+			return "Этот заказ больше недоступен."
+		}
+		return "This order is no longer available."
+	}
+}
+
+// telegramPaymentRequest is a completed Stars payment forwarded from the bot's outbox through the
+// gateway: the order, the Telegram charge id (the idempotency key), the stars paid, and the payer.
+type telegramPaymentRequest struct {
+	OrderID                 string `json:"order_id"`
+	TelegramPaymentChargeID string `json:"telegram_payment_charge_id"`
+	Amount                  int64  `json:"amount"`
+	TelegramUserID          int64  `json:"telegram_user_id"`
+}
+
+// telegramPaymentResponse reports the durable outcome to the bot: Credited is true once the order
+// is credited (or already was). A false with a 200 means the payment was recorded but not creditable
+// (the bot drops it); a 5xx means a transient failure the bot retries.
+type telegramPaymentResponse struct {
+	Credited bool `json:"credited"`
+}
+
+// handleTelegramPayment credits a completed Telegram Stars payment, reached only through the gateway
+// (the bot's ForwardPayment, forwarded on the internal route). It credits the matched order exactly
+// once (idempotent on the Telegram charge id, honoured even if the order expired) and records a
+// succeeded event. A permanent rejection (unknown order, amount mismatch) is answered 200 with
+// Credited=false so the bot stops retrying a payment it cannot place; a transient failure is a 5xx
+// the bot retries.
+func (s *Server) handleTelegramPayment(c *gin.Context) {
+	var req telegramPaymentRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		abortBadRequest(c, "invalid request body")
+		return
+	}
+	orderID, err := uuid.Parse(req.OrderID)
+	if err != nil {
+		s.log.Warn("telegram payment: bad order id", zap.String("charge", req.TelegramPaymentChargeID))
+		c.JSON(http.StatusOK, telegramPaymentResponse{Credited: false})
+		return
+	}
+	paid, err := payments.MoneyFromMinor(req.Amount, payments.CurrencyStar)
+	if err != nil {
+		c.JSON(http.StatusOK, telegramPaymentResponse{Credited: false})
+		return
+	}
+	ctx := c.Request.Context()
+	outcome, err := s.payments.Fund(ctx, orderID, providerTelegram, req.TelegramPaymentChargeID, paid)
+	if err != nil {
+		if errors.Is(err, payments.ErrOrderNotFound) || errors.Is(err, payments.ErrAmountMismatch) ||
+			errors.Is(err, payments.ErrNotAPack) || errors.Is(err, payments.ErrProductNotFound) {
+			// The star charge already happened but the order cannot be placed; record it loudly for
+			// an operator and tell the bot to stop retrying (an operator refunds or credits by hand).
+			s.log.Error("telegram payment rejected (charge taken, not credited)",
+				zap.String("order", orderID.String()), zap.String("charge", req.TelegramPaymentChargeID), zap.Error(err))
+			c.JSON(http.StatusOK, telegramPaymentResponse{Credited: false})
+			return
+		}
+		s.log.Error("telegram fund failed", zap.String("order", orderID.String()), zap.Error(err))
+		c.AbortWithStatusJSON(http.StatusInternalServerError, errorResponse{Error: errorBody{Code: "internal", Message: "internal error"}})
+		return
+	}
+	if !outcome.AlreadyCredited {
+		payload, _ := json.Marshal(map[string]any{"chips": outcome.Chips, "source": string(outcome.Source)})
+		if err := s.payments.RecordPaymentEvent(ctx, outcome.AccountID, &orderID, "succeeded", payload); err != nil {
+			s.log.Error("record telegram payment event failed", zap.String("order", orderID.String()), zap.Error(err))
+		}
+	}
+	c.JSON(http.StatusOK, telegramPaymentResponse{Credited: true})
+}

backend/internal/server/server.go

@@ -31,6 +31,7 @@ import (
 	"scrabble/backend/internal/payments"
 	"scrabble/backend/internal/ratewatch"
 	"scrabble/backend/internal/render"
+	"scrabble/backend/internal/robokassa"
 	"scrabble/backend/internal/session"
 	"scrabble/backend/internal/social"
 	"scrabble/backend/internal/telemetry"
@@ -109,6 +110,9 @@ type Deps struct {
 	// Renderer is the image-render sidecar client for the PNG export artifact. A
 	// nil Renderer makes the PNG download answer 404 (the GCG artifact still works).
 	Renderer *render.Client
+	// Robokassa configures the direct-rail (RUB) provider; an empty MerchantLogin leaves the
+	// order and Result-callback endpoints unregistered.
+	Robokassa robokassa.Config
 }
 
 // Server owns the gin engine, the underlying HTTP server and the readiness
@@ -136,6 +140,7 @@ type Server struct {
 	banview     *banview.View
 	ads         *ads.Service
 	payments    *payments.Service
+	robokassa   robokassa.Config
 	notifier    notify.Publisher
 	console     *adminconsole.Renderer
 	exportKey   []byte
@@ -189,6 +194,7 @@ func New(addr string, deps Deps) *Server {
 		banview:       deps.BanView,
 		ads:           deps.Ads,
 		payments:      deps.Payments,
+		robokassa:     deps.Robokassa,
 		notifier:      notifier,
 		renderer:      deps.Renderer,
 		http:          &http.Server{Addr: addr, Handler: engine},

deploy/README.md

@@ -236,6 +236,7 @@ The main host archives Postgres continuously with **pgBackRest** to **Selectel S
 (encrypted at rest, path-style addressing) so the database can be restored to any moment —
 protecting the money ledger and the game state against corruption or host loss. It is the
 primary recovery path; the migration-window `pg_dump` above is the secondary net.
+**Live on the prod main host since v1.13.0** (armed + restore-drilled 2026-07-09).
 
 **Shape.** A daily full **base backup** (a systemd timer on the main host, `04:00`) plus
 **continuous WAL** archived by Postgres `archive_command` (a segment is forced at least every
@@ -258,8 +259,9 @@ absent/NaN-safe, so they stay quiet until archiving is armed.
 `pg_stat_wal`: WAL is generated at **~0.77 MB/day** and the database is **~9.6 MB**. At
 30-day retention on Selectel S3 (~2 ₽/GB·month) the archive is **under ~0.3 GB → well under
 1 ₽/month** (compression halves it again); request volume is trivial. Performance impact is
-**negligible**: archive-push moves tiny compressed segments, and the daily full base backup
+**negligible**: archive-push moves tiny compressed segments, and the daily full base backup is
-is a ~10 MB, sub-second job on the 2 vCPU host. Revisit both if traffic grows ~100× (watch
+small (the whole cluster is ~32 MB → ~3.7 MB compressed in the repo) and checkpoint-bound
+(~1.5 min wall, minimal CPU/I-O) on the 2 vCPU host. Revisit if traffic grows ~100× (watch
 `node_exporter` during a base backup).
 
 **Arming (owner-coordinated, once, before real payments).** Ships disarmed; to turn it on:
@@ -276,14 +278,22 @@ is a ~10 MB, sub-second job on the 2 vCPU host. Revisit both if traffic grows ~1
 2. Promote `development → master`, tag, and run **prod-deploy**. The roll recreates postgres
    with `archive_mode=on` behind the maintenance page. (Archive pushes fail harmlessly for the
    minute until step 3 creates the repository — the WAL is retained, not lost.)
-3. On the main host, create the repository, take the first base backup, and verify:
+3. On the main host, create the repository, verify archiving, take the first base backup. Run
+   pgBackRest **as the `postgres` OS user** (`-u postgres` — lock-dir/PGDATA consistency with
+   `archive-push`) and connect to the DB **as the superuser role** (`--pg1-user=scrabble`, the
+   `POSTGRES_USER`, not `postgres`); it inherits the container's `PGBACKREST_*` env:
    ```sh
-   docker exec scrabble-postgres pgbackrest --stanza=scrabble stanza-create
+   docker exec -u postgres scrabble-postgres pgbackrest --stanza=scrabble --pg1-user=scrabble stanza-create
-   docker exec scrabble-postgres pgbackrest --stanza=scrabble --type=full backup
+   docker exec -u postgres scrabble-postgres pgbackrest --stanza=scrabble --pg1-user=scrabble check
-   docker exec scrabble-postgres pgbackrest --stanza=scrabble check
+   docker exec -u postgres scrabble-postgres pgbackrest --stanza=scrabble --pg1-user=scrabble --type=full backup
+   docker exec -u postgres scrabble-postgres pgbackrest --stanza=scrabble info   # (info takes no --pg1-user)
    ```
-4. Enable the daily timer: `ansible-playbook site.yml -e pitr_enabled=true` (installs + starts
+   The few `archive-push` failures logged between `archive_mode=on` and `stanza-create` are the
-   `pgbackrest-backup.timer` on the main host).
+   expected transient (WAL retained, not lost); clear the counter afterwards with
+   `docker exec -u postgres scrabble-postgres psql -U scrabble -d scrabble -c "SELECT pg_stat_reset_shared('archiver');"`
+   so it does not trip the failing-archive alert.
+4. Enable the daily timer: `ansible-playbook site.yml --limit main -e pitr_enabled=true`
+   (installs + starts `pgbackrest-backup.timer` on the main host).
 5. Confirm in Grafana that the two archiving alerts are green (`last_archive_age` now tracks a
    real number, `failed_count` flat).
 
@@ -292,17 +302,26 @@ an **isolated, one-shot** target (a throwaway VM or a container with no ingress)
 the matching Postgres major, an empty `PGDATA`, and the same `PGBACKREST_*` environment:
 
 ```sh
-pgbackrest --stanza=scrabble --type=time "--target=YYYY-MM-DD HH:MM:SS+00" --delta restore
+# Throwaway container from the DB image (carries pgBackRest), the live PGBACKREST_* env, an
-# start Postgres; it replays WAL to the target; then verify a known row / the ledger tail
+# empty PGDATA and no app network; restore, recover, verify, then wipe (-v drops the data).
+IMG=$(docker inspect -f '{{.Config.Image}}' scrabble-postgres)
+docker exec scrabble-postgres env | grep '^PGBACKREST_' > /tmp/drill.env; echo POSTGRES_PASSWORD=drill >> /tmp/drill.env
+docker run -d --name pitr-drill --env-file /tmp/drill.env --entrypoint sleep "$IMG" infinity
+docker exec pitr-drill sh -c 'rm -rf /var/lib/postgresql/data/*; chown -R postgres:postgres /var/lib/postgresql/data; chmod 700 /var/lib/postgresql/data'
+# --type=immediate = to the base backup's consistency point; --type=time "--target=<ts>" for PITR
+docker exec -u postgres pitr-drill pgbackrest --stanza=scrabble --pg1-path=/var/lib/postgresql/data --type=immediate restore
+docker exec -u postgres pitr-drill pg_ctl -D /var/lib/postgresql/data -w start
+docker exec -u postgres pitr-drill psql -U scrabble -d scrabble -c "SELECT count(*) FROM backend.accounts;"  # verify data intact
+docker rm -fv pitr-drill; rm -f /tmp/drill.env   # wipe the restored real data
 ```
 
 The target holds **real money + personal data** while it exists — keep it network-isolated and
 **destroy it (wipe `PGDATA` + the instance) afterwards**. Record each drill (date, target
 timestamp, outcome) here:
 
-| Date | Target timestamp | Result |
+| Date | Target | Result |
 | --- | --- | --- |
-| _pending first arming_ | — | — |
+| 2026-07-09 | latest (`--type=immediate`) | PASS — v1.13.0 arming: 31.9 MB cluster restored from the encrypted S3 repo (3.7 MB compressed), recovered to consistency, `backend.accounts` intact; drill instance wiped. |
 
 **bot-link cert rotation:** regenerate (`deploy/gen-certs.sh /tmp/c --force`), reset the
 five `PROD_BOTLINK_*` secrets from `/tmp/c`, and re-run the workflow — both hosts redeploy

deploy/ansible/roles/main/templates/pgbackrest-backup.service.j2

@@ -10,6 +10,8 @@ Requires=docker.service
 
 [Service]
 Type=oneshot
-# docker exec runs as the image's postgres user and inherits the container's PGBACKREST_*
+# docker exec defaults to root, so run as the postgres OS user (-u postgres) for lock-dir and
-# environment (the S3 repository + cipher), so no repository config is needed on the host.
+# PGDATA consistency with archive-push, and connect to the database as the superuser role via
-ExecStart=/usr/bin/docker exec scrabble-postgres pgbackrest --stanza=scrabble --type=full backup
+# --pg1-user: that role is the POSTGRES_USER (scrabble), not "postgres". It inherits the
+# container's PGBACKREST_* environment (the S3 repository + cipher), so no host-side config.
+ExecStart=/usr/bin/docker exec -u postgres scrabble-postgres pgbackrest --stanza=scrabble --pg1-user=scrabble --type=full backup

deploy/caddy/Caddyfile

@@ -86,7 +86,7 @@
 	# The game SPA and the Connect edge are served by the gateway. Strip any
 	# client-supplied X-Scrabble-Honeypot here so the gateway only ever honours the
 	# tag the honeypot block sets below (a client cannot self-tag a real request).
-	@gateway path /app /app/* /telegram /telegram/* /vk /vk/* /dict/* /dl/* /metrics/* /telemetry/* /scrabble.edge.v1.Gateway/*
+	@gateway path /app /app/* /telegram /telegram/* /vk /vk/* /dict/* /dl/* /pay/* /metrics/* /telemetry/* /scrabble.edge.v1.Gateway/*
 	handle @gateway {
 		reverse_proxy gateway:8081 {
 			header_up -X-Scrabble-Honeypot

deploy/docker-compose.bot.yml

@@ -28,6 +28,10 @@ services:
       # the manage-topics and delete-messages rights.
       TELEGRAM_SUPPORT_CHAT_ID: ${TELEGRAM_SUPPORT_CHAT_ID:-}
       TELEGRAM_SUPPORT_STATE_DIR: /data
+      # The Telegram Stars payment outbox (shares the bot-state volume). A writable dir enables the
+      # Stars rail; empty disables it. The rail stays inert until a chip pack carries an XTR (Stars)
+      # price, so it is safe to leave on — seeding a Stars price in the admin is the real go-live.
+      TELEGRAM_STARS_OUTBOX_DIR: ${TELEGRAM_STARS_OUTBOX_DIR:-/data}
       TELEGRAM_PROMO_BOT_TOKEN: ${TELEGRAM_PROMO_BOT_TOKEN:-}
       TELEGRAM_BOT_USERNAME: ${TELEGRAM_BOT_USERNAME:-}
       TELEGRAM_BOT_LINK: ${TELEGRAM_BOT_LINK:-}

deploy/docker-compose.yml

@@ -161,6 +161,13 @@ services:
       # recipient(s) (comma-separated allowed). Both empty disables the alert worker.
       BACKEND_SMTP_ADMIN_FROM: ${SMTP_RELAY_ADMIN_FROM:-}
       BACKEND_ADMIN_EMAIL: ${ADMIN_EMAIL:-}
+      # Direct-rail (Robokassa) payment intake: the merchant login + Password1/Password2 and the
+      # test-mode flag (deploy env: TEST_/PROD_BACKEND_ROBOKASSA_*). An empty login leaves the
+      # direct order and Result-callback endpoints unregistered (the rail is off).
+      BACKEND_ROBOKASSA_MERCHANT_LOGIN: ${ROBOKASSA_MERCHANT_LOGIN:-}
+      BACKEND_ROBOKASSA_PASSWORD1: ${ROBOKASSA_PASSWORD1:-}
+      BACKEND_ROBOKASSA_PASSWORD2: ${ROBOKASSA_PASSWORD2:-}
+      BACKEND_ROBOKASSA_TEST: ${ROBOKASSA_TEST:-}
     # The dictionary lives on a named volume seeded from the image on first boot
     # (the image's /opt/dawg is owned by the nonroot UID, which the fresh volume
     # inherits). The admin console writes new version subdirectories here, and the
@@ -378,6 +385,10 @@ services:
       # set the bot must be an admin there with the manage-topics and delete-messages rights.
       TELEGRAM_SUPPORT_CHAT_ID: ${TELEGRAM_SUPPORT_CHAT_ID:-}
       TELEGRAM_SUPPORT_STATE_DIR: /data
+      # The Telegram Stars payment outbox (shares the bot-state volume). A writable dir enables the
+      # Stars rail (pre_checkout + successful_payment + the durable outbox); empty disables it. The
+      # rail stays inert until a chip pack carries an XTR (Stars) price, so it is safe to leave on.
+      TELEGRAM_STARS_OUTBOX_DIR: ${TELEGRAM_STARS_OUTBOX_DIR:-/data}
       # The optional standalone promo bot (its own token) answering /start with a button
       # into the main bot's app. Empty disables it; when set it needs the main bot's
       # @username and the Mini App link (reused from the UI's VITE_TELEGRAM_LINK).

deploy/landing/Caddyfile

@@ -18,10 +18,25 @@
 	@shell not path /assets/*
 	header @shell Cache-Control "no-cache"
 
+	# The static public offer page, rendered from ui/legal/offer_ru.md at build
+	# time into dist/offer/index.html (vite emit-offer plugin). Served with its own
+	# index so /offer/ resolves to /srv/offer/index.html rather than falling to the
+	# landing shell below (whose index is landing.html). A bare /offer redirects in.
+	handle /offer {
+		redir * /offer/ permanent
+	}
+	handle /offer/* {
+		file_server {
+			index index.html
+		}
+	}
+
 	# An unknown path falls back to the landing shell (the gateway's old "/"
 	# behaviour); "/" itself resolves through the index below.
+	handle {
 		try_files {path} /landing.html
 		file_server {
 			index landing.html
 		}
 	}
+}

docs/ARCHITECTURE.md

@@ -971,7 +971,13 @@ the console; the backend calls them on the **gateway's bot-link relay**, which f
 to the bot and **awaits its delivery ack** (so the console still reports delivered/not). Beyond
 messages the same bot-link carries a **chat-gate control path** — a `ChatGate` command sets a user's
 write access in the moderated discussion chat and the bot's unary `ResolveChatEligibility` resolves a
-joiner's eligibility (neither renders a message; see *Moderated discussion chat* below). An optional
+joiner's eligibility (neither renders a message; see *Moderated discussion chat* below). It also
+carries the **Telegram Stars payment path** (§payments): a `CreateInvoice` command has the bot mint a
+`createInvoiceLink` (XTR) and return it in the Ack; the bot's unary `ValidatePreCheckout` gates a
+`pre_checkout_query` against the intake (declining an already-paid reusable invoice before the
+charge); and its unary `ForwardPayment` delivers a completed `successful_payment` — durably queued in
+a bot-side **SQLite outbox** (`platform/telegram/internal/outbox`, re-driven on restart) — which the
+gateway proxies to the backend intake, credited once (idempotent on `telegram_payment_charge_id`). An optional
 **standalone promo bot** runs in the bot container (`TELEGRAM_PROMO_BOT_TOKEN`): a second bot
 answering `/start` with a URL button into the **main** bot's Mini App (`?startapp`, since a `web_app`
 button would sign initData with the promo token); it is self-contained — no bot-link, no gateway.
@@ -1328,7 +1334,8 @@ in-compose **caddy** is the contour's edge: it owns a single `/_gm` Basic-Auth a
 routes `/_gm/grafana/*` to **Grafana** (anonymous-admin, so the one shared login gates
 it with no per-user Grafana accounts) and the rest of `/_gm/*` to the backend-rendered
 **admin console**; `/app/`, `/telegram/`, `/vk/` and the Connect path go to the gateway; the
-catch-all — notably the landing at `/` — goes to the landing container. The
+catch-all — notably the landing at `/`, plus the static public offer at `/offer/`
+(rendered from `ui/legal/offer_ru.md` at build time) — goes to the landing container. The
 **Telegram validator** runs as a separate container with **no public ingress**,
 answering only internal gRPC (HMAC, no Telegram egress). The **Telegram bot** holds
 no inbound port either: it dials the gateway's **bot-link** (mTLS) and egresses to

docs/PAYMENTS.md

@@ -219,12 +219,21 @@ the amount, credits, marks `paid`. **Idempotency:** dedup by `(provider, provide
 valid callback is **always** honoured, even on an expired order (`expired` ≠ cancellation —
 the money is real, the chips are owed). The user sees only successful purchases.
 
-**TG bot outbox.** `successful_payment` reaches the bot only (Bot API, not the Mini App), and
+**TG Stars.** Only the **bot** reaches Telegram, so the whole rail funnels through the reverse
-the bot host is weak and can lose connectivity, so the bot is a durable link. Store-and-
+mTLS **bot-link** (bot ↔ gateway; the bot cannot dial the backend). The invoice is minted by the
-forward on **SQLite** on the bot's disk: receive → store → ack the Telegram update → forward
+bot: on the order path the gateway sends a `CreateInvoice` command and the bot returns a
-to payments (idempotent, dedup by `telegram_payment_charge_id`) → ack → mark `forwarded`.
+`createInvoiceLink` (XTR) in its Ack, which the Mini App opens with `WebApp.openInvoice`. Before any
-Retries with backoff; re-drives undelivered on restart. At-least-once delivery + idempotent
+star moves the bot answers `pre_checkout_query` via a bot→gateway `ValidatePreCheckout` unary
-intake = credited exactly once.
+(backed by the intake): approve only if the order exists, is still creditable and is **not already
+paid** — a Stars invoice link is reusable, so this gate is the one place a repeat payment is stopped
+before the charge; the decline reason is localised to the order account's language.
+
+`successful_payment` reaches the bot only (Bot API, not the Mini App), and the bot host is weak and
+can lose connectivity, so the bot is a durable link. Store-and-forward on **SQLite** on the bot's
+disk (`internal/outbox`): persist on receipt (idempotent on `telegram_payment_charge_id`) → forward
+over the bot-link (a `ForwardPayment` unary; the gateway proxies to the intake) → on a durable
+response, mark `forwarded`. Re-drives undelivered on restart and on a periodic tick. At-least-once
+delivery + idempotent intake (dedup by `telegram_payment_charge_id`) = credited exactly once.
 
 **Events.** The payments domain writes `payment_events` (succeeded / failed / refunded); a
 dispatcher fans out over channels — the live gRPC stream if the user is in-app, else the

docs/PAYMENTS_ru.md

@@ -220,12 +220,22 @@ provider_payment_id)`.
 Валидный колбэк исполняется **всегда**, даже на истёкшем заказе (`expired` ≠ отмена —
 деньги реальны, Фишки должны быть выданы). Пользователь видит только успешные покупки.
 
-**Outbox TG-бота.** `successful_payment` приходит только боту (Bot API, не Mini App), а
+**TG Stars.** До Telegram дотягивается только **бот**, поэтому весь рельс идёт через обратный
-хост бота слабый и может терять связь, поэтому бот — durable-звено. Store-and-forward на
+mTLS **bot-link** (бот ↔ gateway; напрямую к бэкенду бот не ходит). Инвойс создаёт бот: на пути
-**SQLite** на диске бота: получил → сохранил → подтвердил апдейт Telegram → форвардит в
+заказа gateway шлёт команду `CreateInvoice`, а бот возвращает `createInvoiceLink` (XTR) в Ack,
-платёжный домен (идемпотентно, дедуп по `telegram_payment_charge_id`) → ack → пометил
+который Mini App открывает через `WebApp.openInvoice`. До списания звёзд бот отвечает на
-`forwarded`. Ретраи с backoff; дореталивает недоставленное при рестарте. Доставка
+`pre_checkout_query` через унарный вызов бот→gateway `ValidatePreCheckout` (за ним — приём): одобрить,
-at-least-once + идемпотентный приём = начисление ровно один раз.
+только если заказ существует, ещё оплачиваем и **не оплачен ранее** — ссылка Stars-инвойса
+переиспользуема, так что этот гейт — единственное место, где повторная оплата отсекается **до**
+списания; текст отказа локализован в язык аккаунта заказа.
+
+**Outbox TG-бота.** `successful_payment` приходит только боту (Bot API, не Mini App), а хост бота
+слабый и может терять связь, поэтому бот — durable-звено. Store-and-forward на **SQLite** на диске
+бота (`internal/outbox`): сохранил при получении (идемпотентно по `telegram_payment_charge_id`) →
+форвардит по bot-link (унарный `ForwardPayment`; gateway проксирует в приём) → при durable-ответе
+пометил `forwarded`. Дореталивает недоставленное при рестарте и по периодическому тику. Доставка
+at-least-once + идемпотентный приём (дедуп по `telegram_payment_charge_id`) = начисление ровно один
+раз.
 
 **События.** Платёжный домен пишет `payment_events` (succeeded / failed / refunded);
 диспетчер рассылает по каналам — live gRPC-стрим, если пользователь в аппе, иначе

gateway/cmd/gateway/main.go

@@ -153,6 +153,16 @@ func run(ctx context.Context, cfg config.Config, logger *zap.Logger) error {
 				r, rerr := backend.ChatEligibility(ctx, externalID)
 				return r.Registered, r.Eligible, rerr
 			})
+		// The Telegram Stars payment bridge rides the same bot-link: the bot validates each
+		// pre_checkout and forwards each completed payment through these, backed by the backend intake.
+		botHub.SetPaymentBridge(
+			func(ctx context.Context, orderID string, amount int64, currency string) (bool, string, error) {
+				return backend.ValidatePreCheckout(ctx, orderID, amount, currency)
+			},
+			func(ctx context.Context, orderID, chargeID string, amount, telegramUserID int64) (bool, error) {
+				return backend.TelegramPayment(ctx, orderID, chargeID, amount, telegramUserID)
+			},
+		)
 		tlsCfg, terr := mtls.ServerConfig(cfg.BotLink.CertFile, cfg.BotLink.KeyFile, cfg.BotLink.CAFile)
 		if terr != nil {
 			return terr
@@ -199,7 +209,12 @@ func run(ctx context.Context, cfg config.Config, logger *zap.Logger) error {
 		vkidExchanger = vkid.New(cfg.VKID.AppID, cfg.VKID.ClientSecret, cfg.VKID.RedirectURI)
 		logger.Info("vk id web login enabled")
 	}
-	registry := transcode.NewRegistry(backend, validator, transcode.WithVKAuth(cfg.VKAppSecret), transcode.WithVKLink(vkidExchanger))
+	regOpts := []transcode.Option{transcode.WithVKAuth(cfg.VKAppSecret), transcode.WithVKLink(vkidExchanger)}
+	if botHub != nil {
+		// A Telegram-context wallet order mints its Stars invoice link through the connected bot.
+		regOpts = append(regOpts, transcode.WithTelegramStars(botHub))
+	}
+	registry := transcode.NewRegistry(backend, validator, regOpts...)
 	edge := connectsrv.NewServer(connectsrv.Deps{
 		Registry:     registry,
 		Sessions:     sessions,
@@ -208,6 +223,7 @@ func run(ctx context.Context, cfg config.Config, logger *zap.Logger) error {
 		Tracker:      tracker,
 		Banlist:      banlist,
 		Honeytoken:   cfg.Abuse.Honeytoken,
+		VKAppSecret:  cfg.VKAppSecret,
 		Hub:          hub,
 		RateLimit:    cfg.RateLimit,
 		Heartbeat:    cfg.PushHeartbeatInterval,

gateway/internal/backendclient/api.go

@@ -396,6 +396,89 @@ func (c *Client) WalletBuy(ctx context.Context, userID, productID string) (Walle
 	return out, err
 }
 
+// walletOrderBody is the POST body of an order: the chip pack to fund.
+type walletOrderBody struct {
+	ProductID string `json:"product_id"`
+}
+
+// WalletOrderResp is a created order: its id and the rail's launch details. RedirectURL is the
+// provider's hosted-payment URL (direct); Rail names the settling rail; for the Telegram Stars rail
+// InvoiceTitle and InvoiceAmount (whole stars) are the invoice the gateway mints via the bot.
+type WalletOrderResp struct {
+	OrderID       string `json:"order_id"`
+	RedirectURL   string `json:"redirect_url"`
+	Rail          string `json:"rail"`
+	InvoiceTitle  string `json:"invoice_title"`
+	InvoiceAmount int64  `json:"invoice_amount"`
+}
+
+// WalletOrder opens a pending order to fund a chip pack and returns the rail's launch details.
+func (c *Client) WalletOrder(ctx context.Context, userID, productID string) (WalletOrderResp, error) {
+	var out WalletOrderResp
+	err := c.do(ctx, http.MethodPost, "/api/v1/user/wallet/order", userID, "", walletOrderBody{ProductID: productID}, &out)
+	return out, err
+}
+
+// preCheckoutResp is the backend intake's pre_checkout answer.
+type preCheckoutResp struct {
+	OK     bool   `json:"ok"`
+	Reason string `json:"reason"`
+}
+
+// ValidatePreCheckout asks the backend intake whether a Telegram Stars pre_checkout_query for
+// orderID paying amount in currency may be approved, before the charge. It returns the approval and
+// a short decline reason for the payer. It backs the bot's pre_checkout gate through the bot-link.
+func (c *Client) ValidatePreCheckout(ctx context.Context, orderID string, amount int64, currency string) (bool, string, error) {
+	var out preCheckoutResp
+	err := c.do(ctx, http.MethodPost, "/api/v1/internal/payments/telegram/precheckout", "", "",
+		map[string]any{"order_id": orderID, "amount": amount, "currency": currency}, &out)
+	return out.OK, out.Reason, err
+}
+
+// telegramPaymentResp is the backend intake's credit outcome.
+type telegramPaymentResp struct {
+	Credited bool `json:"credited"`
+}
+
+// TelegramPayment forwards a completed Telegram Stars payment from the bot's outbox to the backend
+// intake, which credits the order idempotently on chargeID. It reports whether the order was
+// credited (or already had been); a transport error is a transient failure the bot retries.
+func (c *Client) TelegramPayment(ctx context.Context, orderID, chargeID string, amount, telegramUserID int64) (bool, error) {
+	var out telegramPaymentResp
+	err := c.do(ctx, http.MethodPost, "/api/v1/internal/payments/telegram/payment", "", "",
+		map[string]any{
+			"order_id":                   orderID,
+			"telegram_payment_charge_id": chargeID,
+			"amount":                     amount,
+			"telegram_user_id":           telegramUserID,
+		}, &out)
+	return out.Credited, err
+}
+
+// robokassaResultResp is the backend intake's reply: the body to echo back to Robokassa.
+type robokassaResultResp struct {
+	Response string `json:"response"`
+}
+
+// RobokassaResult forwards a Robokassa Result callback's parameters to the backend intake (the
+// single writer, which verifies the signature and credits) and returns the body to echo to
+// Robokassa ("OK<InvId>"). params carries the provider's raw form fields.
+func (c *Client) RobokassaResult(ctx context.Context, params map[string]string) (string, error) {
+	var out robokassaResultResp
+	err := c.do(ctx, http.MethodPost, "/api/v1/internal/payments/robokassa/result", "", "", params, &out)
+	return out.Response, err
+}
+
+// VKCallback forwards a gateway-verified VK payment callback's parameters to the backend intake and
+// returns the backend's raw VK response envelope (`{"response":…}` or `{"error":…}`) for the gateway
+// to relay to VK verbatim. The backend answers 200 in every case (VK's protocol), so a transport
+// error here is a genuine proxy failure.
+func (c *Client) VKCallback(ctx context.Context, params map[string]string) (json.RawMessage, error) {
+	var out json.RawMessage
+	err := c.do(ctx, http.MethodPost, "/api/v1/internal/payments/vk/callback", "", "", params, &out)
+	return out, err
+}
+
 // CatalogAtomResp is one atom line of a storefront product: the value type it grants and quantity.
 type CatalogAtomResp struct {
 	AtomType string `json:"atom_type"`

gateway/internal/botlink/command.go

@@ -48,3 +48,18 @@ func ChatGateCommand(externalID string, allow bool) *botlinkv1.Command {
 		}},
 	}
 }
+
+// CreateInvoiceCommand builds a Telegram Stars invoice-mint command: the bot calls
+// createInvoiceLink (in XTR) with the given title and description, the order id as the
+// payload (echoed by Telegram in pre_checkout and successful_payment) and amountStars whole
+// stars, and returns the link in its Ack result.
+func CreateInvoiceCommand(title, description, orderID string, amountStars int64) *botlinkv1.Command {
+	return &botlinkv1.Command{
+		Payload: &botlinkv1.Command_CreateInvoice{CreateInvoice: &botlinkv1.CreateInvoiceCommand{
+			Title:       title,
+			Description: description,
+			Payload:     orderID,
+			Amount:      amountStars,
+		}},
+	}
+}

gateway/internal/botlink/hub.go

@@ -13,6 +13,7 @@ import (
 	"strconv"
 	"sync"
 	"sync/atomic"
+	"time"
 
 	"go.opentelemetry.io/otel/attribute"
 	"go.opentelemetry.io/otel/metric"
@@ -31,6 +32,11 @@ var ErrNoBot = errors.New("botlink: no bot connected")
 // (at-most-once under backpressure).
 const outboundBuffer = 64
 
+// invoiceMintTimeout bounds one synchronous invoice-mint round-trip (the gateway commands the bot
+// and awaits the Ack carrying the createInvoiceLink result), so a hung or slow bot cannot stall the
+// caller's wallet-order request indefinitely.
+const invoiceMintTimeout = 15 * time.Second
+
 // EligibilityResolver answers a Telegram identity's moderated-chat write eligibility
 // for the bot's join-time ResolveChatEligibility query: registered reports whether the
 // identity maps to an account, eligible is the final gate the bot acts on (registered
@@ -38,6 +44,17 @@ const outboundBuffer = 64
 // chat-access endpoint.
 type EligibilityResolver func(ctx context.Context, externalID string) (registered, eligible bool, err error)
 
+// PreCheckoutResolver validates a Telegram Stars pre_checkout_query for the bot's
+// ValidatePreCheckout query: it answers whether the order may still be charged (ok) and, when not,
+// a short reason to show the payer. The gateway backs it with the backend intake.
+type PreCheckoutResolver func(ctx context.Context, orderID string, amount int64, currency string) (ok bool, reason string, err error)
+
+// PaymentForwarder delivers a completed Telegram Stars payment for the bot's ForwardPayment call:
+// it credits the order through the backend intake and reports whether it was credited (or already
+// had been). A non-nil error is a transient failure the bot retries. The gateway backs it with the
+// backend intake.
+type PaymentForwarder func(ctx context.Context, orderID, chargeID string, amount, telegramUserID int64) (credited bool, err error)
+
 // Hub registers connected bots and routes send commands to them. A single bot is
 // expected today; the registry already holds a set so adding more later needs no
 // rewrite.
@@ -46,6 +63,10 @@ type Hub struct {
 
 	log         *zap.Logger
 	eligibility EligibilityResolver
+	// precheck and forward back the Telegram Stars payment RPCs; nil until SetPaymentBridge wires
+	// them, in which case the RPCs report Unavailable. Set once before the gRPC server serves.
+	precheck PreCheckoutResolver
+	forward  PaymentForwarder
 
 	mu      sync.Mutex
 	links   map[*link]struct{}
@@ -147,6 +168,105 @@ func (h *Hub) ResolveChatEligibility(ctx context.Context, req *botlinkv1.ChatEli
 	return &botlinkv1.ChatEligibilityResponse{Registered: registered, Eligible: eligible}, nil
 }
 
+// SetPaymentBridge wires the Telegram Stars payment resolvers, backing ValidatePreCheckout and
+// ForwardPayment. It must be called before the gRPC server starts serving (the fields are read
+// without a lock, relying on that happens-before). A nil resolver leaves its RPC reporting
+// Unavailable.
+func (h *Hub) SetPaymentBridge(precheck PreCheckoutResolver, forward PaymentForwarder) {
+	h.precheck = precheck
+	h.forward = forward
+}
+
+// ValidatePreCheckout serves the bot's pre_checkout validation over the same mTLS channel: it
+// delegates to the configured resolver (the backend intake) and returns whether the order may be
+// charged. A resolver failure maps to Internal, which the bot treats as a decline (fail-closed).
+func (h *Hub) ValidatePreCheckout(ctx context.Context, req *botlinkv1.PreCheckoutRequest) (*botlinkv1.PreCheckoutResponse, error) {
+	if h.precheck == nil {
+		return nil, status.Error(codes.Unavailable, "payment bridge not configured")
+	}
+	ok, reason, err := h.precheck(ctx, req.GetOrderId(), req.GetAmount(), req.GetCurrency())
+	if err != nil {
+		h.log.Warn("validate pre_checkout failed", zap.String("order", req.GetOrderId()), zap.Error(err))
+		return nil, status.Error(codes.Internal, "validate pre_checkout")
+	}
+	return &botlinkv1.PreCheckoutResponse{Ok: ok, Reason: reason}, nil
+}
+
+// ForwardPayment serves the bot's completed-payment delivery: it credits the order through the
+// configured forwarder (the backend intake) and reports the durable outcome. A forwarder failure
+// maps to Internal, which the bot treats as transient and retries; a clean response (credited true
+// or false) lets the bot forget the outbox row.
+func (h *Hub) ForwardPayment(ctx context.Context, req *botlinkv1.ForwardPaymentRequest) (*botlinkv1.ForwardPaymentResponse, error) {
+	if h.forward == nil {
+		return nil, status.Error(codes.Unavailable, "payment bridge not configured")
+	}
+	credited, err := h.forward(ctx, req.GetOrderId(), req.GetTelegramPaymentChargeId(), req.GetAmount(), req.GetTelegramUserId())
+	if err != nil {
+		h.log.Warn("forward telegram payment failed", zap.String("order", req.GetOrderId()), zap.Error(err))
+		return nil, status.Error(codes.Internal, "forward payment")
+	}
+	return &botlinkv1.ForwardPaymentResponse{Credited: credited}, nil
+}
+
+// MintInvoice commands the connected bot to mint a Telegram Stars invoice link for the order and
+// returns the link. It is a bounded, synchronous round-trip (invoiceMintTimeout): no bot connected
+// returns ErrNoBot, and a bot error or an empty link is an error the caller surfaces as a failed
+// order launch.
+func (h *Hub) MintInvoice(ctx context.Context, title, description, orderID string, amountStars int64) (string, error) {
+	cctx, cancel := context.WithTimeout(ctx, invoiceMintTimeout)
+	defer cancel()
+	ack, err := h.sendAwaitAck(cctx, CreateInvoiceCommand(title, description, orderID, amountStars))
+	if err != nil {
+		return "", err
+	}
+	if ack.GetResult() == "" {
+		return "", errors.New("botlink: bot returned an empty invoice link")
+	}
+	return ack.GetResult(), nil
+}
+
+// sendAwaitAck enqueues a command and waits for the bot's full Ack (or ctx). It mirrors SendAwait
+// but returns the Ack — the invoice-mint path needs its result field — and reports ctx expiry as an
+// error rather than a not-delivered, since a timed-out mint has no link to return.
+func (h *Hub) sendAwaitAck(ctx context.Context, cmd *botlinkv1.Command) (*botlinkv1.Ack, error) {
+	l, ok := h.pick()
+	if !ok {
+		h.count("dropped")
+		return nil, ErrNoBot
+	}
+	id := h.nextID()
+	cmd.CommandId = id
+	ackc := make(chan *botlinkv1.Ack, 1)
+	h.mu.Lock()
+	h.pending[id] = ackc
+	h.mu.Unlock()
+	defer func() {
+		h.mu.Lock()
+		delete(h.pending, id)
+		h.mu.Unlock()
+	}()
+
+	select {
+	case l.out <- &botlinkv1.ToBot{Command: cmd}:
+	case <-ctx.Done():
+		h.count("dropped")
+		return nil, ctx.Err()
+	}
+
+	select {
+	case ack := <-ackc:
+		if e := ack.GetError(); e != "" {
+			h.count("error")
+			return nil, errors.New(e)
+		}
+		h.count(deliveredLabel(ack.GetDelivered()))
+		return ack, nil
+	case <-ctx.Done():
+		h.count("error")
+		return nil, ctx.Err()
+	}
+}
+
 // register adds a connected bot.
 func (h *Hub) register(l *link) {
 	h.mu.Lock()

gateway/internal/connectsrv/server.go

@@ -31,6 +31,7 @@ import (
 	"scrabble/gateway/internal/ratelimit"
 	"scrabble/gateway/internal/session"
 	"scrabble/gateway/internal/transcode"
+	"scrabble/gateway/internal/vkpay"
 	"scrabble/gateway/internal/webui"
 	edgev1 "scrabble/gateway/proto/edge/v1"
 	"scrabble/gateway/proto/edge/v1/edgev1connect"
@@ -77,6 +78,7 @@ type Server struct {
 	tracker     *ratelimit.Tracker
 	banlist     *ratelimit.Banlist
 	honeytoken  string
+	vkAppSecret string
 	hub         *push.Hub
 	heartbeat   time.Duration
 	log         *zap.Logger
@@ -110,6 +112,9 @@ type Deps struct {
 	// Honeytoken, when non-empty, is the planted bearer value whose presentation
 	// bans the caller and raises a high-severity alarm.
 	Honeytoken string
+	// VKAppSecret is the VK Mini App protected key; it verifies the VK payment callback signature
+	// (the same key the launch-signature auth uses). Empty leaves the VK callback rejecting.
+	VKAppSecret string
 	Hub         *push.Hub
 	RateLimit   config.RateLimitConfig
 	Heartbeat   time.Duration
@@ -151,6 +156,7 @@ func NewServer(d Deps) *Server {
 		registry:     d.Registry,
 		sessions:     d.Sessions,
 		backend:      d.Backend,
+		vkAppSecret:  d.VKAppSecret,
 		limiter:      limiter,
 		tracker:      tracker,
 		banlist:      banlist,
@@ -196,6 +202,12 @@ func (s *Server) HTTPHandler() http.Handler {
 	// through this session-gated route (not public); see dictBytesHandler.
 	mux.Handle("/dict/", s.dictBytesHandler())
 	mux.Handle("/dl/", s.exportDownloadHandler())
+	// Direct-rail (Robokassa) return + callback routes: the server Result callback (the single
+	// crediting signal, proxied to the backend intake) and the browser Success/Fail redirects.
+	mux.Handle("/pay/robokassa/result", s.robokassaResultHandler())
+	mux.Handle("/pay/vk/callback", s.vkCallbackHandler())
+	mux.Handle("/pay/robokassa/success", s.robokassaReturnHandler("Оплата принята."))
+	mux.Handle("/pay/robokassa/fail", s.robokassaReturnHandler("Оплата не завершена."))
 	// The client posts its local-move-preview adoption telemetry here (session-gated).
 	mux.Handle("/metrics/local-eval", s.localEvalMetricsHandler())
 	// The index.html boot guard beacons here when it turns a client away on the unsupported-engine
@@ -482,6 +494,102 @@ func (s *Server) exportDownloadHandler() http.Handler {
 	})
 }
 
+// robokassaResultHandler proxies the Robokassa Result callback to the backend intake (the single
+// writer). It rate-limits per IP, forwards the provider's form parameters, and echoes the backend's
+// "OK<InvId>" to Robokassa on success; any error tells Robokassa the notification was not accepted,
+// so it retries. The gateway does not verify the signature — the backend holds the secret.
+func (s *Server) robokassaResultHandler() http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if s.backend == nil {
+			http.NotFound(w, r)
+			return
+		}
+		ip := peerIP(r.RemoteAddr, r.Header)
+		if !s.limiter.Allow("public:"+ip, s.publicPolicy) {
+			s.noteRateLimited(r.Context(), classPublic, ip, "robokassa-result")
+			http.Error(w, "rate limited", http.StatusTooManyRequests)
+			return
+		}
+		if err := r.ParseForm(); err != nil {
+			http.Error(w, "bad request", http.StatusBadRequest)
+			return
+		}
+		params := make(map[string]string, len(r.Form))
+		for k := range r.Form {
+			params[k] = r.Form.Get(k)
+		}
+		resp, err := s.backend.RobokassaResult(r.Context(), params)
+		if err != nil {
+			s.log.Warn("robokassa result proxy failed", zap.Error(err))
+			http.Error(w, "not accepted", http.StatusBadGateway)
+			return
+		}
+		w.Header().Set("Content-Type", "text/plain; charset=utf-8")
+		_, _ = w.Write([]byte(resp))
+	})
+}
+
+// vkCallbackHandler proxies a VK Mini Apps payment callback to the backend intake. It rate-limits
+// per IP, verifies the VK signature with the app's protected key (the backend holds no VK secret),
+// forwards the provider's parameters, and relays the backend's VK response envelope. A missing or
+// bad signature is rejected before reaching the backend.
+func (s *Server) vkCallbackHandler() http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if s.backend == nil {
+			http.NotFound(w, r)
+			return
+		}
+		ip := peerIP(r.RemoteAddr, r.Header)
+		if !s.limiter.Allow("public:"+ip, s.publicPolicy) {
+			s.noteRateLimited(r.Context(), classPublic, ip, "vk-callback")
+			http.Error(w, "rate limited", http.StatusTooManyRequests)
+			return
+		}
+		if err := r.ParseForm(); err != nil {
+			http.Error(w, "bad request", http.StatusBadRequest)
+			return
+		}
+		params := make(map[string]string, len(r.Form))
+		for k := range r.Form {
+			params[k] = r.Form.Get(k)
+		}
+		if !vkpay.Verify(params, s.vkAppSecret) {
+			s.log.Warn("vk callback: bad signature")
+			http.Error(w, "bad signature", http.StatusForbidden)
+			return
+		}
+		resp, err := s.backend.VKCallback(r.Context(), params)
+		if err != nil {
+			s.log.Warn("vk callback proxy failed", zap.Error(err))
+			http.Error(w, "bad gateway", http.StatusBadGateway)
+			return
+		}
+		w.Header().Set("Content-Type", "application/json; charset=utf-8")
+		_, _ = w.Write(resp)
+	})
+}
+
+// robokassaReturnHandler serves a minimal self-closing page for Robokassa's Success/Fail browser
+// return. The payment opens in a separate window, so on return this closes that window and drops the
+// customer back into the live app (never a cold app start); a link is the fallback if the window
+// cannot self-close. The credit rides the server Result callback, never this redirect — the wallet
+// updates in place from the payment push, with a return-focus refetch as the fallback.
+func (s *Server) robokassaReturnHandler(message string) http.Handler {
+	page := []byte(`<!doctype html>
+<html lang="ru"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1"><title>Оплата</title></head>
+<body style="font-family: system-ui, sans-serif; text-align: center; padding: 48px 20px; color: #1a1c20">
+<p style="font-size: 1.1rem">` + message + `</p>
+<p style="color: #5b6472">Можно закрыть это окно и вернуться в приложение.</p>
+<p><a href="/app/">Открыть приложение</a></p>
+<script>setTimeout(function () { try { window.close(); } catch (e) {} }, 1200);</script>
+</body></html>`)
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "text/html; charset=utf-8")
+		w.Header().Set("Cache-Control", "no-store")
+		_, _ = w.Write(page)
+	})
+}
+
 func (s *Server) dictBytesHandler() http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		if s.backend == nil {

gateway/internal/transcode/encode.go

@@ -37,6 +37,19 @@ func encodeAck(ok bool) []byte {
 	return b.FinishedBytes()
 }
 
+// encodeWalletOrder builds a WalletOrderResponse payload: the created order id and the provider
+// launch URL the client opens.
+func encodeWalletOrder(o backendclient.WalletOrderResp) []byte {
+	b := flatbuffers.NewBuilder(128)
+	oid := b.CreateString(o.OrderID)
+	url := b.CreateString(o.RedirectURL)
+	fb.WalletOrderResponseStart(b)
+	fb.WalletOrderResponseAddOrderId(b, oid)
+	fb.WalletOrderResponseAddRedirectUrl(b, url)
+	b.Finish(fb.WalletOrderResponseEnd(b))
+	return b.FinishedBytes()
+}
+
 // encodeDeleteRequestResult builds an AccountDeleteRequestResult payload reporting which
 // deletion step-up the account uses ("email" | "phrase").
 func encodeDeleteRequestResult(method string) []byte {

gateway/internal/transcode/transcode.go

@@ -55,6 +55,7 @@ const (
 	MsgWalletGet            = "wallet.get"
 	MsgWalletCatalog        = "wallet.catalog"
 	MsgWalletBuy            = "wallet.buy"
+	MsgWalletOrder          = "wallet.order"
 )
 
 // Request is one decoded Execute call.
@@ -111,6 +112,7 @@ func NewRegistry(backend *backendclient.Client, tg TelegramValidator, opts ...Op
 	r.ops[MsgWalletGet] = Op{Handler: walletHandler(backend), Auth: true}
 	r.ops[MsgWalletCatalog] = Op{Handler: walletCatalogHandler(backend), Auth: true}
 	r.ops[MsgWalletBuy] = Op{Handler: walletBuyHandler(backend), Auth: true}
+	r.ops[MsgWalletOrder] = Op{Handler: walletOrderHandler(backend, nil), Auth: true}
 	r.ops[MsgBlockStatus] = Op{Handler: blockStatusHandler(backend), Auth: true}
 	r.ops[MsgGameSubmitPlay] = Op{Handler: submitPlayHandler(backend), Auth: true}
 	r.ops[MsgGameState] = Op{Handler: gameStateHandler(backend), Auth: true}
@@ -168,6 +170,17 @@ func WithVKLink(ex VKIDExchanger) Option {
 	}
 }
 
+// WithTelegramStars re-registers the wallet.order op with a Telegram Stars invoice minter (the
+// bot-link), so a Telegram-context order mints its Stars invoice link through the bot. A nil minter
+// is a no-op, leaving the default (Stars-unavailable) handler in place.
+func WithTelegramStars(minter InvoiceMinter) Option {
+	return func(r *Registry, backend *backendclient.Client) {
+		if minter != nil {
+			r.ops[MsgWalletOrder] = Op{Handler: walletOrderHandler(backend, minter), Auth: true}
+		}
+	}
+}
+
 // Lookup returns the operation for messageType, and whether it is registered.
 func (r *Registry) Lookup(messageType string) (Op, bool) {
 	op, ok := r.ops[messageType]
@@ -331,6 +344,41 @@ func walletBuyHandler(backend *backendclient.Client) Handler {
 	}
 }
 
+// InvoiceMinter mints a Telegram Stars invoice link for a created order via the bot (only the bot
+// reaches Telegram). The gateway bot-link Hub implements it; it is nil where the bot-link is off,
+// which leaves the Telegram rail unavailable.
+type InvoiceMinter interface {
+	MintInvoice(ctx context.Context, title, description, orderID string, amountStars int64) (string, error)
+}
+
+// errTelegramStarsUnavailable is returned when a Telegram Stars order is requested but no invoice
+// minter (the bot-link) is wired — the rail is not available on this gateway.
+var errTelegramStarsUnavailable = errors.New("telegram stars rail unavailable")
+
+func walletOrderHandler(backend *backendclient.Client, minter InvoiceMinter) Handler {
+	return func(ctx context.Context, req Request) ([]byte, error) {
+		in := fb.GetRootAsWalletOrderRequest(req.Payload, 0)
+		o, err := backend.WalletOrder(ctx, req.UserID, string(in.ProductId()))
+		if err != nil {
+			return nil, err
+		}
+		// Telegram Stars: mint the invoice link here via the bot-link and return it to the client
+		// as the redirect URL it opens with WebApp.openInvoice. The title doubles as the invoice
+		// description (both are required and the pack title is the whole product).
+		if o.Rail == "telegram" {
+			if minter == nil {
+				return nil, errTelegramStarsUnavailable
+			}
+			link, merr := minter.MintInvoice(ctx, o.InvoiceTitle, o.InvoiceTitle, o.OrderID, o.InvoiceAmount)
+			if merr != nil {
+				return nil, merr
+			}
+			o.RedirectURL = link
+		}
+		return encodeWalletOrder(o), nil
+	}
+}
+
 func blockStatusHandler(backend *backendclient.Client) Handler {
 	return func(ctx context.Context, req Request) ([]byte, error) {
 		bs, err := backend.BlockStatus(ctx, req.UserID)

gateway/internal/vkpay/vkpay.go

@@ -0,0 +1,40 @@
+// Package vkpay verifies VK Mini Apps payment ("голоса") callback signatures. VK signs each
+// payment notification (get_item / order_status_change) and expects the receiving server to verify
+// it with the app's secret before acting. The signature is MD5 — mandated by VK's payment protocol,
+// not a security choice on our part — so this package uses crypto/md5 deliberately.
+package vkpay
+
+import (
+	"crypto/md5"
+	"encoding/hex"
+	"sort"
+	"strings"
+)
+
+// Verify reports whether params carry a valid VK payment signature under secret. VK computes the
+// signature as the MD5 of the sig-excluded parameters, sorted alphabetically by name and
+// concatenated as key=value with no separators, with the app secret appended. The comparison is
+// case-insensitive over the hex digest.
+func Verify(params map[string]string, secret string) bool {
+	got := params["sig"]
+	if got == "" || secret == "" {
+		return false
+	}
+	keys := make([]string, 0, len(params))
+	for k := range params {
+		if k == "sig" {
+			continue
+		}
+		keys = append(keys, k)
+	}
+	sort.Strings(keys)
+	var b strings.Builder
+	for _, k := range keys {
+		b.WriteString(k)
+		b.WriteString("=")
+		b.WriteString(params[k])
+	}
+	b.WriteString(secret)
+	sum := md5.Sum([]byte(b.String()))
+	return strings.EqualFold(hex.EncodeToString(sum[:]), got)
+}

gateway/internal/vkpay/vkpay_test.go

@@ -0,0 +1,74 @@
+package vkpay
+
+import (
+	"crypto/md5"
+	"encoding/hex"
+	"maps"
+	"sort"
+	"strings"
+	"testing"
+)
+
+// vkSig computes a valid VK signature the way VK does, for the fixtures (sig excluded, sorted
+// key=value concatenation, secret appended, MD5 hex).
+func vkSig(params map[string]string, secret string) string {
+	keys := make([]string, 0, len(params))
+	for k := range params {
+		if k == "sig" {
+			continue
+		}
+		keys = append(keys, k)
+	}
+	sort.Strings(keys)
+	var b strings.Builder
+	for _, k := range keys {
+		b.WriteString(k + "=" + params[k])
+	}
+	b.WriteString(secret)
+	sum := md5.Sum([]byte(b.String()))
+	return hex.EncodeToString(sum[:])
+}
+
+func clone(m map[string]string) map[string]string {
+	out := make(map[string]string, len(m))
+	maps.Copy(out, m)
+	return out
+}
+
+func TestVerify(t *testing.T) {
+	const secret = "app_secret"
+	base := map[string]string{
+		"notification_type": "order_status_change",
+		"app_id":            "123",
+		"user_id":           "456",
+		"receiver_id":       "456",
+		"order_id":          "789",
+		"date":              "1700000000",
+		"status":            "chargeable",
+		"item":              "019f47a0-6f9e-7000-8000-000000000000",
+		"item_price":        "10",
+	}
+	valid := clone(base)
+	// VK sends the digest uppercase; the verifier must accept it case-insensitively.
+	valid["sig"] = strings.ToUpper(vkSig(base, secret))
+
+	if !Verify(valid, secret) {
+		t.Fatal("valid VK signature rejected")
+	}
+
+	tampered := clone(valid)
+	tampered["item_price"] = "1"
+	if Verify(tampered, secret) {
+		t.Error("accepted a tampered amount")
+	}
+
+	if Verify(valid, "wrong-secret") {
+		t.Error("accepted under the wrong secret")
+	}
+
+	noSig := clone(valid)
+	delete(noSig, "sig")
+	if Verify(noSig, secret) {
+		t.Error("accepted a callback with no signature")
+	}
+}

go.work.sum

@@ -73,10 +73,12 @@ github.com/golang-sql/sqlexp v0.1.0/go.mod h1:J4ad9Vo8ZCWQ2GMrC4UCQy1JpCbwU9m3EO
 github.com/golang/glog v1.2.5 h1:DrW6hGnjIhtvhOIiAKT6Psh/Kd/ldepEa81DKeiRJ5I=
 github.com/golang/glog v1.2.5/go.mod h1:6AhwSGph0fcJtXVM/PEHPqZlFeoLxhs7/t5UDAwmO+w=
 github.com/golang/protobuf v1.5.0/go.mod h1:FsONVRAS9T7sI+LIUmWTfcYkHO4aIWwzhcaSAoJOfIk=
+github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
 github.com/google/gofuzz v1.0.0 h1:A8PeW59pxE9IoFRqBp37U+mSNaQoZ46F1f0f863XSXw=
 github.com/google/pprof v0.0.0-20211214055906-6f57359322fd h1:1FjCyPC+syAzJ5/2S8fqdZK1R22vvA0J7JZKcuOIQ7Y=
 github.com/google/pprof v0.0.0-20211214055906-6f57359322fd/go.mod h1:KgnwoLYCZ8IQu3XUZ8Nc/bM9CCZFOyjUNOSygVozoDg=
 github.com/google/renameio v0.1.0 h1:GOZbcHa3HfsPKPlmyPyN2KEohoMXOhdMbHrvbpl2QaA=
+github.com/hashicorp/golang-lru/v2 v2.0.7/go.mod h1:QeFd9opnmA6QUJc5vARoKUSoFhyfM2/ZepoAG6RGpeM=
 github.com/iliadenisov/alphabet v1.1.0 h1:d87N7Rmpjj9FgL7bvEaqLdaIaNch2hC6HvkbKGhn7Hk=
 github.com/iliadenisov/alphabet v1.1.0/go.mod h1:h6BhDBiJBLhMEb5XfsqJXZop3hhwXaD8lc5yf38Baqw=
 github.com/iliadenisov/dafsa v1.1.0 h1:NV1ZOstMdHXI/cCyAZKOD3qnKLoYdMUunA0+Baj7vR4=
@@ -95,6 +97,7 @@ github.com/klauspost/compress v1.17.6/go.mod h1:/dCuZOvVtNoHsyb+cuJD3itjs3NbnF6K
 github.com/konsorten/go-windows-terminal-sequences v1.0.2 h1:DB17ag19krx9CFsz4o3enTrPXyIXCl+2iCXH/aMAp9s=
 github.com/kr/pty v1.1.8 h1:AkaSdXYQOWeaO3neb8EM634ahkXXe3jYbVh/F9lq+GI=
 github.com/mattn/go-colorable v0.1.6 h1:6Su7aK7lXmJ/U79bYtBjLNaha4Fs1Rg9plHpcH+vvnE=
+github.com/mattn/go-isatty v0.0.20/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y=
 github.com/mattn/go-sqlite3 v1.14.28 h1:ThEiQrnbtumT+QMknw63Befp/ce/nUPgBPMlRFEum7A=
 github.com/mattn/go-sqlite3 v1.14.28/go.mod h1:Uh1q+B4BYcTPb+yiD3kU8Ct7aC0hY9fxUwlHK0RXw+Y=
 github.com/mfridman/xflag v0.1.0 h1:TWZrZwG1QklFX5S4j1vxfF1sZbZeZSGofMwPMLAF29M=
@@ -146,8 +149,6 @@ github.com/volatiletech/randomize v0.0.1 h1:eE5yajattWqTB2/eN8df4dw+8jwAzBtbdo5s
 github.com/volatiletech/randomize v0.0.1/go.mod h1:GN3U0QYqfZ9FOJ67bzax1cqZ5q2xuj2mXrXBjWaRTlY=
 github.com/volatiletech/strmangle v0.0.1 h1:UKQoHmY6be/R3tSvD2nQYrH41k43OJkidwEiC74KIzk=
 github.com/volatiletech/strmangle v0.0.1/go.mod h1:F6RA6IkB5vq0yTG4GQ0UsbbRcl3ni9P76i+JrTBKFFg=
-github.com/wneessen/go-mail v0.7.3 h1:g3DravXC5SMlVdboFrQA8Jx95A8sOzoBeS5F+vzNRK0=
-github.com/wneessen/go-mail v0.7.3/go.mod h1:QGhBX0yNbc1J+Mkjcu7z2rpj4B4l+BmDY8gYznPC9sk=
 github.com/xdg-go/pbkdf2 v1.0.0 h1:Su7DPu48wXMwC3bs7MCNG+z4FhcyEuz5dlvchbq0B0c=
 github.com/xdg-go/pbkdf2 v1.0.0/go.mod h1:jrpuAogTd400dnrH08LKmI/xc1MbPOebTwRqcT5RDeI=
 github.com/xdg-go/scram v1.2.0 h1:bYKF2AEwG5rqd1BumT4gAnvwU/M9nBp2pTSxeZw7Wvs=
@@ -176,6 +177,7 @@ golang.org/x/exp v0.0.0-20260410095643-746e56fc9e2f h1:W3F4c+6OLc6H2lb//N1q4WpJk
 golang.org/x/exp v0.0.0-20260410095643-746e56fc9e2f/go.mod h1:J1xhfL/vlindoeF/aINzNzt2Bket5bjo9sdOYzOsU80=
 golang.org/x/lint v0.0.0-20190930215403-16217165b5de h1:5hukYrvBGR8/eNkX5mdUezrA6JiaEZDtJb9Ei+1LlBs=
 golang.org/x/mod v0.32.0/go.mod h1:SgipZ/3h2Ci89DlEtEXWUk/HteuRin+HHhN+WbNhguU=
+golang.org/x/mod v0.33.0/go.mod h1:swjeQEj+6r7fODbD2cqrnje9PnziFuw4bmLbBZFrQ5w=
 golang.org/x/mod v0.34.0 h1:xIHgNUUnW6sYkcM5Jleh05DvLOtwc6RitGHbDk4akRI=
 golang.org/x/mod v0.34.0/go.mod h1:ykgH52iCZe79kzLLMhyCUzhMci+nQj+0XkbXpNYtVjY=
 golang.org/x/mod v0.35.0/go.mod h1:+GwiRhIInF8wPm+4AoT6L0FA1QWAad3OMdTRx4tFYlU=
@@ -183,10 +185,14 @@ golang.org/x/oauth2 v0.34.0/go.mod h1:lzm5WQJQwKZ3nwavOZ3IS5Aulzxi68dUSgRHujetwE
 golang.org/x/oauth2 v0.35.0 h1:Mv2mzuHuZuY2+bkyWXIHMfhNdJAdwW3FuWeCPYN5GVQ=
 golang.org/x/oauth2 v0.35.0/go.mod h1:lzm5WQJQwKZ3nwavOZ3IS5Aulzxi68dUSgRHujetwEA=
 golang.org/x/sync v0.19.0/go.mod h1:9KTHXmSnoGruLpwFjVSX0lNNA75CykiMECbovNTZqGI=
+golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.28.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/sys v0.41.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
+golang.org/x/telemetry v0.0.0-20260409153401-be6f6cb8b1fa/go.mod h1:kHjTxDEnAu6/Nl9lDkzjWpR+bmKfxeiRuSDlsMb70gE=
 golang.org/x/term v0.40.0/go.mod h1:w2P8uVp06p2iyKKuvXIm7N/y0UCRt3UfJTfZ7oOpglM=
-golang.org/x/text v0.37.0/go.mod h1:a5sjxXGs9hsn/AJVwuElvCAo9v8QYLzvavO5z2PiM38=
 golang.org/x/time v0.11.0/go.mod h1:CDIdPxbZBQxdj6cxyCIdrNogrJKMJ7pr37NYpMcMDSg=
 golang.org/x/tools v0.41.0/go.mod h1:XSY6eDqxVNiYgezAVqqCeihT4j1U2CCsqvH3WhQpnlg=
+golang.org/x/tools v0.42.0/go.mod h1:Ma6lCIwGZvHK6XtgbswSoWroEkhugApmsXyrUmBhfr0=
 golang.org/x/tools v0.43.0 h1:12BdW9CeB3Z+J/I/wj34VMl8X+fEXBxVR90JeMX5E7s=
 golang.org/x/tools v0.43.0/go.mod h1:uHkMso649BX2cZK6+RpuIPXS3ho2hZo4FVwfoy1vIk0=
 golang.org/x/tools v0.44.0/go.mod h1:KA0AfVErSdxRZIsOVipbv3rQhVXTnlU6UhKxHd1seDI=
@@ -200,6 +206,17 @@ gopkg.in/yaml.v2 v2.2.2 h1:ZCJp+EgiOT7lHqUV2J862kp8Qj64Jo6az82+3Td9dZw=
 honnef.co/go/tools v0.0.1-2019.2.3 h1:3JgtbtFHMiCmsznwGVTUWbgGov+pVqnlf1dEJTNAXeM=
 howett.net/plist v1.0.1 h1:37GdZ8tP09Q35o9ych3ehygcsL+HqKSwzctveSlarvM=
 howett.net/plist v1.0.1/go.mod h1:lqaXoTrLY4hg8tnEzNru53gicrbv7rrk+2xJA/7hw9g=
+modernc.org/cc/v4 v4.28.1/go.mod h1:OnovgIhbbMXMu1aISnJ0wvVD1KnW+cAUJkIrAWh+kVI=
+modernc.org/ccgo/v4 v4.33.0/go.mod h1:+RhXBoRYzRwaH21mV/aj6XvQRDtfjcZfAlPMsQo8CR0=
+modernc.org/fileutil v1.4.0/go.mod h1:EqdKFDxiByqxLk8ozOxObDSfcVOv/54xDs/DUHdvCUU=
+modernc.org/gc/v2 v2.6.5/go.mod h1:YgIahr1ypgfe7chRuJi2gD7DBQiKSLMPgBQe9oIiito=
+modernc.org/gc/v3 v3.1.2/go.mod h1:HFK/6AGESC7Ex+EZJhJ2Gni6cTaYpSMmU/cT9RmlfYY=
+modernc.org/goabi0 v0.2.0/go.mod h1:CEFRnnJhKvWT1c1JTI3Avm+tgOWbkOu5oPA8eH8LnMI=
+modernc.org/libc v1.72.0/go.mod h1:tTU8DL8A+XLVkEY3x5E/tO7s2Q/q42EtnNWda/L5QhQ=
+modernc.org/opt v0.2.0/go.mod h1:03fq9lsNfvkYSfxrfUhZCWPk1lm4cq4N+Bh//bEtgns=
+modernc.org/sortutil v1.2.1/go.mod h1:7ZI3a3REbai7gzCLcotuw9AC4VZVpYMjDzETGsSMqJE=
+modernc.org/strutil v1.2.1/go.mod h1:EHkiggD70koQxjVdSBM3JKM7k6L0FbGE5eymy9i3B9A=
+modernc.org/token v1.1.0/go.mod h1:UGzOrNV1mAFSEB63lOFHIpNRUVMvYTc6yu1SMY/XTDM=
 mvdan.cc/xurls/v2 v2.6.0 h1:3NTZpeTxYVWNSokW3MKeyVkz/j7uYXYiMtXRUfmjbgI=
 mvdan.cc/xurls/v2 v2.6.0/go.mod h1:bCvEZ1XvdA6wDnxY7jPPjEmigDtvtvPXAD/Exa9IMSk=
 rsc.io/pdf v0.1.1 h1:k1MczvYDUvJBe93bYd7wrZLLUEcLZAuF824/I4e5Xr4=

pkg/fbs/scrabble.fbs

@@ -873,6 +873,18 @@ table WalletBuyRequest {
   product_id:string;
 }
 
+// WalletOrderRequest opens a money order to fund a chip pack: the pack to buy.
+table WalletOrderRequest {
+  product_id:string;
+}
+
+// WalletOrderResponse returns the created order id and the provider launch URL the client opens
+// (the Robokassa hosted-payment page); chips are credited later, by the verified server callback.
+table WalletOrderResponse {
+  order_id:string;
+  redirect_url:string;
+}
+
 // CatalogAtom is one atom line of a storefront product: the base value type it grants
 // ("chips"/"hints"/"noads_days"/"tournament") and how many of it the product carries.
 table CatalogAtom {

pkg/fbs/scrabblefb/WalletOrderRequest.go

@@ -0,0 +1,60 @@
+// Code generated by the FlatBuffers compiler. DO NOT EDIT.
+
+package scrabblefb
+
+import (
+	flatbuffers "github.com/google/flatbuffers/go"
+)
+
+type WalletOrderRequest struct {
+	_tab flatbuffers.Table
+}
+
+func GetRootAsWalletOrderRequest(buf []byte, offset flatbuffers.UOffsetT) *WalletOrderRequest {
+	n := flatbuffers.GetUOffsetT(buf[offset:])
+	x := &WalletOrderRequest{}
+	x.Init(buf, n+offset)
+	return x
+}
+
+func FinishWalletOrderRequestBuffer(builder *flatbuffers.Builder, offset flatbuffers.UOffsetT) {
+	builder.Finish(offset)
+}
+
+func GetSizePrefixedRootAsWalletOrderRequest(buf []byte, offset flatbuffers.UOffsetT) *WalletOrderRequest {
+	n := flatbuffers.GetUOffsetT(buf[offset+flatbuffers.SizeUint32:])
+	x := &WalletOrderRequest{}
+	x.Init(buf, n+offset+flatbuffers.SizeUint32)
+	return x
+}
+
+func FinishSizePrefixedWalletOrderRequestBuffer(builder *flatbuffers.Builder, offset flatbuffers.UOffsetT) {
+	builder.FinishSizePrefixed(offset)
+}
+
+func (rcv *WalletOrderRequest) Init(buf []byte, i flatbuffers.UOffsetT) {
+	rcv._tab.Bytes = buf
+	rcv._tab.Pos = i
+}
+
+func (rcv *WalletOrderRequest) Table() flatbuffers.Table {
+	return rcv._tab
+}
+
+func (rcv *WalletOrderRequest) ProductId() []byte {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(4))
+	if o != 0 {
+		return rcv._tab.ByteVector(o + rcv._tab.Pos)
+	}
+	return nil
+}
+
+func WalletOrderRequestStart(builder *flatbuffers.Builder) {
+	builder.StartObject(1)
+}
+func WalletOrderRequestAddProductId(builder *flatbuffers.Builder, productId flatbuffers.UOffsetT) {
+	builder.PrependUOffsetTSlot(0, flatbuffers.UOffsetT(productId), 0)
+}
+func WalletOrderRequestEnd(builder *flatbuffers.Builder) flatbuffers.UOffsetT {
+	return builder.EndObject()
+}

pkg/fbs/scrabblefb/WalletOrderResponse.go

@@ -0,0 +1,71 @@
+// Code generated by the FlatBuffers compiler. DO NOT EDIT.
+
+package scrabblefb
+
+import (
+	flatbuffers "github.com/google/flatbuffers/go"
+)
+
+type WalletOrderResponse struct {
+	_tab flatbuffers.Table
+}
+
+func GetRootAsWalletOrderResponse(buf []byte, offset flatbuffers.UOffsetT) *WalletOrderResponse {
+	n := flatbuffers.GetUOffsetT(buf[offset:])
+	x := &WalletOrderResponse{}
+	x.Init(buf, n+offset)
+	return x
+}
+
+func FinishWalletOrderResponseBuffer(builder *flatbuffers.Builder, offset flatbuffers.UOffsetT) {
+	builder.Finish(offset)
+}
+
+func GetSizePrefixedRootAsWalletOrderResponse(buf []byte, offset flatbuffers.UOffsetT) *WalletOrderResponse {
+	n := flatbuffers.GetUOffsetT(buf[offset+flatbuffers.SizeUint32:])
+	x := &WalletOrderResponse{}
+	x.Init(buf, n+offset+flatbuffers.SizeUint32)
+	return x
+}
+
+func FinishSizePrefixedWalletOrderResponseBuffer(builder *flatbuffers.Builder, offset flatbuffers.UOffsetT) {
+	builder.FinishSizePrefixed(offset)
+}
+
+func (rcv *WalletOrderResponse) Init(buf []byte, i flatbuffers.UOffsetT) {
+	rcv._tab.Bytes = buf
+	rcv._tab.Pos = i
+}
+
+func (rcv *WalletOrderResponse) Table() flatbuffers.Table {
+	return rcv._tab
+}
+
+func (rcv *WalletOrderResponse) OrderId() []byte {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(4))
+	if o != 0 {
+		return rcv._tab.ByteVector(o + rcv._tab.Pos)
+	}
+	return nil
+}
+
+func (rcv *WalletOrderResponse) RedirectUrl() []byte {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(6))
+	if o != 0 {
+		return rcv._tab.ByteVector(o + rcv._tab.Pos)
+	}
+	return nil
+}
+
+func WalletOrderResponseStart(builder *flatbuffers.Builder) {
+	builder.StartObject(2)
+}
+func WalletOrderResponseAddOrderId(builder *flatbuffers.Builder, orderId flatbuffers.UOffsetT) {
+	builder.PrependUOffsetTSlot(0, flatbuffers.UOffsetT(orderId), 0)
+}
+func WalletOrderResponseAddRedirectUrl(builder *flatbuffers.Builder, redirectUrl flatbuffers.UOffsetT) {
+	builder.PrependUOffsetTSlot(1, flatbuffers.UOffsetT(redirectUrl), 0)
+}
+func WalletOrderResponseEnd(builder *flatbuffers.Builder) flatbuffers.UOffsetT {
+	return builder.EndObject()
+}

pkg/proto/botlink/v1/botlink.pb.go

@@ -225,6 +225,7 @@ type Command struct {
 	//	*Command_SendToUser
 	//	*Command_SendToChannel
 	//	*Command_ChatGate
+	//	*Command_CreateInvoice
 	Payload       isCommand_Payload `protobuf_oneof:"payload"`
 	unknownFields protoimpl.UnknownFields
 	sizeCache     protoimpl.SizeCache
@@ -310,6 +311,15 @@ func (x *Command) GetChatGate() *ChatGateCommand {
 	return nil
 }
 
+func (x *Command) GetCreateInvoice() *CreateInvoiceCommand {
+	if x != nil {
+		if x, ok := x.Payload.(*Command_CreateInvoice); ok {
+			return x.CreateInvoice
+		}
+	}
+	return nil
+}
+
 type isCommand_Payload interface {
 	isCommand_Payload()
 }
@@ -330,6 +340,10 @@ type Command_ChatGate struct {
 	ChatGate *ChatGateCommand `protobuf:"bytes,5,opt,name=chat_gate,json=chatGate,proto3,oneof"`
 }
 
+type Command_CreateInvoice struct {
+	CreateInvoice *CreateInvoiceCommand `protobuf:"bytes,6,opt,name=create_invoice,json=createInvoice,proto3,oneof"`
+}
+
 func (*Command_Notify) isCommand_Payload() {}
 
 func (*Command_SendToUser) isCommand_Payload() {}
@@ -338,15 +352,20 @@ func (*Command_SendToChannel) isCommand_Payload() {}
 
 func (*Command_ChatGate) isCommand_Payload() {}
 
+func (*Command_CreateInvoice) isCommand_Payload() {}
+
 // Ack reports the outcome of the Command with command_id. delivered mirrors the
 // connector delivery semantics (false when the kind is not rendered out-of-app, the
 // user never started the bot, or no channel is configured); error carries an
-// unexpected transport/render failure, distinct from a clean not-delivered.
+// unexpected transport/render failure, distinct from a clean not-delivered. result
+// carries a command's return value when it has one (the created invoice link for a
+// create_invoice command); it is empty otherwise.
 type Ack struct {
 	state         protoimpl.MessageState `protogen:"open.v1"`
 	CommandId     string                 `protobuf:"bytes,1,opt,name=command_id,json=commandId,proto3" json:"command_id,omitempty"`
 	Delivered     bool                   `protobuf:"varint,2,opt,name=delivered,proto3" json:"delivered,omitempty"`
 	Error         string                 `protobuf:"bytes,3,opt,name=error,proto3" json:"error,omitempty"`
+	Result        string                 `protobuf:"bytes,4,opt,name=result,proto3" json:"result,omitempty"`
 	unknownFields protoimpl.UnknownFields
 	sizeCache     protoimpl.SizeCache
 }
@@ -402,6 +421,13 @@ func (x *Ack) GetError() string {
 	return ""
 }
 
+func (x *Ack) GetResult() string {
+	if x != nil {
+		return x.Result
+	}
+	return ""
+}
+
 // ChatGateCommand sets a Telegram user's write access in the moderated discussion
 // chat. external_id is the user's Telegram identity (as in the backend identities
 // table); allow grants the right to write when true and revokes it when false. The
@@ -562,6 +588,314 @@ func (x *ChatEligibilityResponse) GetEligible() bool {
 	return false
 }
 
+// CreateInvoiceCommand asks the bot to mint a Telegram Stars invoice link for a
+// pending order (createInvoiceLink in XTR). payload is the order id, which Telegram
+// echoes back in the pre_checkout_query and the successful_payment; amount is the
+// price in whole stars; title and description are shown on the invoice. The bot
+// returns the link in its Ack result.
+type CreateInvoiceCommand struct {
+	state         protoimpl.MessageState `protogen:"open.v1"`
+	Title         string                 `protobuf:"bytes,1,opt,name=title,proto3" json:"title,omitempty"`
+	Description   string                 `protobuf:"bytes,2,opt,name=description,proto3" json:"description,omitempty"`
+	Payload       string                 `protobuf:"bytes,3,opt,name=payload,proto3" json:"payload,omitempty"`
+	Amount        int64                  `protobuf:"varint,4,opt,name=amount,proto3" json:"amount,omitempty"`
+	unknownFields protoimpl.UnknownFields
+	sizeCache     protoimpl.SizeCache
+}
+
+func (x *CreateInvoiceCommand) Reset() {
+	*x = CreateInvoiceCommand{}
+	mi := &file_botlink_v1_botlink_proto_msgTypes[8]
+	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+	ms.StoreMessageInfo(mi)
+}
+
+func (x *CreateInvoiceCommand) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*CreateInvoiceCommand) ProtoMessage() {}
+
+func (x *CreateInvoiceCommand) ProtoReflect() protoreflect.Message {
+	mi := &file_botlink_v1_botlink_proto_msgTypes[8]
+	if x != nil {
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		if ms.LoadMessageInfo() == nil {
+			ms.StoreMessageInfo(mi)
+		}
+		return ms
+	}
+	return mi.MessageOf(x)
+}
+
+// Deprecated: Use CreateInvoiceCommand.ProtoReflect.Descriptor instead.
+func (*CreateInvoiceCommand) Descriptor() ([]byte, []int) {
+	return file_botlink_v1_botlink_proto_rawDescGZIP(), []int{8}
+}
+
+func (x *CreateInvoiceCommand) GetTitle() string {
+	if x != nil {
+		return x.Title
+	}
+	return ""
+}
+
+func (x *CreateInvoiceCommand) GetDescription() string {
+	if x != nil {
+		return x.Description
+	}
+	return ""
+}
+
+func (x *CreateInvoiceCommand) GetPayload() string {
+	if x != nil {
+		return x.Payload
+	}
+	return ""
+}
+
+func (x *CreateInvoiceCommand) GetAmount() int64 {
+	if x != nil {
+		return x.Amount
+	}
+	return 0
+}
+
+// PreCheckoutRequest asks whether a Stars pre_checkout_query for order_id at amount
+// (whole stars) in currency may be approved before the charge.
+type PreCheckoutRequest struct {
+	state         protoimpl.MessageState `protogen:"open.v1"`
+	OrderId       string                 `protobuf:"bytes,1,opt,name=order_id,json=orderId,proto3" json:"order_id,omitempty"`
+	Amount        int64                  `protobuf:"varint,2,opt,name=amount,proto3" json:"amount,omitempty"`
+	Currency      string                 `protobuf:"bytes,3,opt,name=currency,proto3" json:"currency,omitempty"`
+	unknownFields protoimpl.UnknownFields
+	sizeCache     protoimpl.SizeCache
+}
+
+func (x *PreCheckoutRequest) Reset() {
+	*x = PreCheckoutRequest{}
+	mi := &file_botlink_v1_botlink_proto_msgTypes[9]
+	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+	ms.StoreMessageInfo(mi)
+}
+
+func (x *PreCheckoutRequest) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*PreCheckoutRequest) ProtoMessage() {}
+
+func (x *PreCheckoutRequest) ProtoReflect() protoreflect.Message {
+	mi := &file_botlink_v1_botlink_proto_msgTypes[9]
+	if x != nil {
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		if ms.LoadMessageInfo() == nil {
+			ms.StoreMessageInfo(mi)
+		}
+		return ms
+	}
+	return mi.MessageOf(x)
+}
+
+// Deprecated: Use PreCheckoutRequest.ProtoReflect.Descriptor instead.
+func (*PreCheckoutRequest) Descriptor() ([]byte, []int) {
+	return file_botlink_v1_botlink_proto_rawDescGZIP(), []int{9}
+}
+
+func (x *PreCheckoutRequest) GetOrderId() string {
+	if x != nil {
+		return x.OrderId
+	}
+	return ""
+}
+
+func (x *PreCheckoutRequest) GetAmount() int64 {
+	if x != nil {
+		return x.Amount
+	}
+	return 0
+}
+
+func (x *PreCheckoutRequest) GetCurrency() string {
+	if x != nil {
+		return x.Currency
+	}
+	return ""
+}
+
+// PreCheckoutResponse is the approval answer. ok approves the charge; reason carries a
+// short user-facing decline message when ok is false.
+type PreCheckoutResponse struct {
+	state         protoimpl.MessageState `protogen:"open.v1"`
+	Ok            bool                   `protobuf:"varint,1,opt,name=ok,proto3" json:"ok,omitempty"`
+	Reason        string                 `protobuf:"bytes,2,opt,name=reason,proto3" json:"reason,omitempty"`
+	unknownFields protoimpl.UnknownFields
+	sizeCache     protoimpl.SizeCache
+}
+
+func (x *PreCheckoutResponse) Reset() {
+	*x = PreCheckoutResponse{}
+	mi := &file_botlink_v1_botlink_proto_msgTypes[10]
+	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+	ms.StoreMessageInfo(mi)
+}
+
+func (x *PreCheckoutResponse) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*PreCheckoutResponse) ProtoMessage() {}
+
+func (x *PreCheckoutResponse) ProtoReflect() protoreflect.Message {
+	mi := &file_botlink_v1_botlink_proto_msgTypes[10]
+	if x != nil {
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		if ms.LoadMessageInfo() == nil {
+			ms.StoreMessageInfo(mi)
+		}
+		return ms
+	}
+	return mi.MessageOf(x)
+}
+
+// Deprecated: Use PreCheckoutResponse.ProtoReflect.Descriptor instead.
+func (*PreCheckoutResponse) Descriptor() ([]byte, []int) {
+	return file_botlink_v1_botlink_proto_rawDescGZIP(), []int{10}
+}
+
+func (x *PreCheckoutResponse) GetOk() bool {
+	if x != nil {
+		return x.Ok
+	}
+	return false
+}
+
+func (x *PreCheckoutResponse) GetReason() string {
+	if x != nil {
+		return x.Reason
+	}
+	return ""
+}
+
+// ForwardPaymentRequest carries a completed Stars payment: order_id from the invoice
+// payload, the Telegram charge id (the idempotency key), the amount in whole stars,
+// and the payer's Telegram user id.
+type ForwardPaymentRequest struct {
+	state                   protoimpl.MessageState `protogen:"open.v1"`
+	OrderId                 string                 `protobuf:"bytes,1,opt,name=order_id,json=orderId,proto3" json:"order_id,omitempty"`
+	TelegramPaymentChargeId string                 `protobuf:"bytes,2,opt,name=telegram_payment_charge_id,json=telegramPaymentChargeId,proto3" json:"telegram_payment_charge_id,omitempty"`
+	Amount                  int64                  `protobuf:"varint,3,opt,name=amount,proto3" json:"amount,omitempty"`
+	TelegramUserId          int64                  `protobuf:"varint,4,opt,name=telegram_user_id,json=telegramUserId,proto3" json:"telegram_user_id,omitempty"`
+	unknownFields           protoimpl.UnknownFields
+	sizeCache               protoimpl.SizeCache
+}
+
+func (x *ForwardPaymentRequest) Reset() {
+	*x = ForwardPaymentRequest{}
+	mi := &file_botlink_v1_botlink_proto_msgTypes[11]
+	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+	ms.StoreMessageInfo(mi)
+}
+
+func (x *ForwardPaymentRequest) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*ForwardPaymentRequest) ProtoMessage() {}
+
+func (x *ForwardPaymentRequest) ProtoReflect() protoreflect.Message {
+	mi := &file_botlink_v1_botlink_proto_msgTypes[11]
+	if x != nil {
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		if ms.LoadMessageInfo() == nil {
+			ms.StoreMessageInfo(mi)
+		}
+		return ms
+	}
+	return mi.MessageOf(x)
+}
+
+// Deprecated: Use ForwardPaymentRequest.ProtoReflect.Descriptor instead.
+func (*ForwardPaymentRequest) Descriptor() ([]byte, []int) {
+	return file_botlink_v1_botlink_proto_rawDescGZIP(), []int{11}
+}
+
+func (x *ForwardPaymentRequest) GetOrderId() string {
+	if x != nil {
+		return x.OrderId
+	}
+	return ""
+}
+
+func (x *ForwardPaymentRequest) GetTelegramPaymentChargeId() string {
+	if x != nil {
+		return x.TelegramPaymentChargeId
+	}
+	return ""
+}
+
+func (x *ForwardPaymentRequest) GetAmount() int64 {
+	if x != nil {
+		return x.Amount
+	}
+	return 0
+}
+
+func (x *ForwardPaymentRequest) GetTelegramUserId() int64 {
+	if x != nil {
+		return x.TelegramUserId
+	}
+	return 0
+}
+
+// ForwardPaymentResponse reports the durable outcome. credited is true when the order
+// was credited (or already had been); false means the payment was recorded but could
+// not be matched to a creditable order (an operator follows up). Either way the bot
+// may forget the outbox row — only a transport error triggers a retry.
+type ForwardPaymentResponse struct {
+	state         protoimpl.MessageState `protogen:"open.v1"`
+	Credited      bool                   `protobuf:"varint,1,opt,name=credited,proto3" json:"credited,omitempty"`
+	unknownFields protoimpl.UnknownFields
+	sizeCache     protoimpl.SizeCache
+}
+
+func (x *ForwardPaymentResponse) Reset() {
+	*x = ForwardPaymentResponse{}
+	mi := &file_botlink_v1_botlink_proto_msgTypes[12]
+	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+	ms.StoreMessageInfo(mi)
+}
+
+func (x *ForwardPaymentResponse) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*ForwardPaymentResponse) ProtoMessage() {}
+
+func (x *ForwardPaymentResponse) ProtoReflect() protoreflect.Message {
+	mi := &file_botlink_v1_botlink_proto_msgTypes[12]
+	if x != nil {
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		if ms.LoadMessageInfo() == nil {
+			ms.StoreMessageInfo(mi)
+		}
+		return ms
+	}
+	return mi.MessageOf(x)
+}
+
+// Deprecated: Use ForwardPaymentResponse.ProtoReflect.Descriptor instead.
+func (*ForwardPaymentResponse) Descriptor() ([]byte, []int) {
+	return file_botlink_v1_botlink_proto_rawDescGZIP(), []int{12}
+}
+
+func (x *ForwardPaymentResponse) GetCredited() bool {
+	if x != nil {
+		return x.Credited
+	}
+	return false
+}
+
 var File_botlink_v1_botlink_proto protoreflect.FileDescriptor
 
 const file_botlink_v1_botlink_proto_rawDesc = "" +
@@ -576,7 +910,7 @@ const file_botlink_v1_botlink_proto_rawDesc = "" +
 	"\x05Hello\x12\x1f\n" +
 	"\vinstance_id\x18\x01 \x01(\tR\n" +
 	"instanceId\x12!\n" +
-	"\fowns_updates\x18\x02 \x01(\bR\vownsUpdates\"\xde\x02\n" +
+	"\fowns_updates\x18\x02 \x01(\bR\vownsUpdates\"\xb2\x03\n" +
 	"\aCommand\x12\x1d\n" +
 	"\n" +
 	"command_id\x18\x01 \x01(\tR\tcommandId\x12=\n" +
@@ -584,13 +918,15 @@ const file_botlink_v1_botlink_proto_rawDesc = "" +
 	"\fsend_to_user\x18\x03 \x01(\v2'.scrabble.telegram.v1.SendToUserRequestH\x00R\n" +
 	"sendToUser\x12X\n" +
 	"\x0fsend_to_channel\x18\x04 \x01(\v2..scrabble.telegram.v1.SendToGameChannelRequestH\x00R\rsendToChannel\x12C\n" +
-	"\tchat_gate\x18\x05 \x01(\v2$.scrabble.botlink.v1.ChatGateCommandH\x00R\bchatGateB\t\n" +
+	"\tchat_gate\x18\x05 \x01(\v2$.scrabble.botlink.v1.ChatGateCommandH\x00R\bchatGate\x12R\n" +
-	"\apayload\"X\n" +
+	"\x0ecreate_invoice\x18\x06 \x01(\v2).scrabble.botlink.v1.CreateInvoiceCommandH\x00R\rcreateInvoiceB\t\n" +
+	"\apayload\"p\n" +
 	"\x03Ack\x12\x1d\n" +
 	"\n" +
 	"command_id\x18\x01 \x01(\tR\tcommandId\x12\x1c\n" +
 	"\tdelivered\x18\x02 \x01(\bR\tdelivered\x12\x14\n" +
-	"\x05error\x18\x03 \x01(\tR\x05error\"H\n" +
+	"\x05error\x18\x03 \x01(\tR\x05error\x12\x16\n" +
+	"\x06result\x18\x04 \x01(\tR\x06result\"H\n" +
 	"\x0fChatGateCommand\x12\x1f\n" +
 	"\vexternal_id\x18\x01 \x01(\tR\n" +
 	"externalId\x12\x14\n" +
@@ -602,10 +938,31 @@ const file_botlink_v1_botlink_proto_rawDesc = "" +
 	"\n" +
 	"registered\x18\x01 \x01(\bR\n" +
 	"registered\x12\x1a\n" +
-	"\beligible\x18\x02 \x01(\bR\beligible2\xc4\x01\n" +
+	"\beligible\x18\x02 \x01(\bR\beligible\"\x80\x01\n" +
+	"\x14CreateInvoiceCommand\x12\x14\n" +
+	"\x05title\x18\x01 \x01(\tR\x05title\x12 \n" +
+	"\vdescription\x18\x02 \x01(\tR\vdescription\x12\x18\n" +
+	"\apayload\x18\x03 \x01(\tR\apayload\x12\x16\n" +
+	"\x06amount\x18\x04 \x01(\x03R\x06amount\"c\n" +
+	"\x12PreCheckoutRequest\x12\x19\n" +
+	"\border_id\x18\x01 \x01(\tR\aorderId\x12\x16\n" +
+	"\x06amount\x18\x02 \x01(\x03R\x06amount\x12\x1a\n" +
+	"\bcurrency\x18\x03 \x01(\tR\bcurrency\"=\n" +
+	"\x13PreCheckoutResponse\x12\x0e\n" +
+	"\x02ok\x18\x01 \x01(\bR\x02ok\x12\x16\n" +
+	"\x06reason\x18\x02 \x01(\tR\x06reason\"\xb1\x01\n" +
+	"\x15ForwardPaymentRequest\x12\x19\n" +
+	"\border_id\x18\x01 \x01(\tR\aorderId\x12;\n" +
+	"\x1atelegram_payment_charge_id\x18\x02 \x01(\tR\x17telegramPaymentChargeId\x12\x16\n" +
+	"\x06amount\x18\x03 \x01(\x03R\x06amount\x12(\n" +
+	"\x10telegram_user_id\x18\x04 \x01(\x03R\x0etelegramUserId\"4\n" +
+	"\x16ForwardPaymentResponse\x12\x1a\n" +
+	"\bcredited\x18\x01 \x01(\bR\bcredited2\x99\x03\n" +
 	"\aBotLink\x12D\n" +
 	"\x04Link\x12\x1c.scrabble.botlink.v1.FromBot\x1a\x1a.scrabble.botlink.v1.ToBot(\x010\x01\x12s\n" +
-	"\x16ResolveChatEligibility\x12+.scrabble.botlink.v1.ChatEligibilityRequest\x1a,.scrabble.botlink.v1.ChatEligibilityResponseB)Z'scrabble/pkg/proto/botlink/v1;botlinkv1b\x06proto3"
+	"\x16ResolveChatEligibility\x12+.scrabble.botlink.v1.ChatEligibilityRequest\x1a,.scrabble.botlink.v1.ChatEligibilityResponse\x12h\n" +
+	"\x13ValidatePreCheckout\x12'.scrabble.botlink.v1.PreCheckoutRequest\x1a(.scrabble.botlink.v1.PreCheckoutResponse\x12i\n" +
+	"\x0eForwardPayment\x12*.scrabble.botlink.v1.ForwardPaymentRequest\x1a+.scrabble.botlink.v1.ForwardPaymentResponseB)Z'scrabble/pkg/proto/botlink/v1;botlinkv1b\x06proto3"
 
 var (
 	file_botlink_v1_botlink_proto_rawDescOnce sync.Once
@@ -619,7 +976,7 @@ func file_botlink_v1_botlink_proto_rawDescGZIP() []byte {
 	return file_botlink_v1_botlink_proto_rawDescData
 }
 
-var file_botlink_v1_botlink_proto_msgTypes = make([]protoimpl.MessageInfo, 8)
+var file_botlink_v1_botlink_proto_msgTypes = make([]protoimpl.MessageInfo, 13)
 var file_botlink_v1_botlink_proto_goTypes = []any{
 	(*FromBot)(nil),                     // 0: scrabble.botlink.v1.FromBot
 	(*ToBot)(nil),                       // 1: scrabble.botlink.v1.ToBot
@@ -629,27 +986,37 @@ var file_botlink_v1_botlink_proto_goTypes = []any{
 	(*ChatGateCommand)(nil),             // 5: scrabble.botlink.v1.ChatGateCommand
 	(*ChatEligibilityRequest)(nil),      // 6: scrabble.botlink.v1.ChatEligibilityRequest
 	(*ChatEligibilityResponse)(nil),     // 7: scrabble.botlink.v1.ChatEligibilityResponse
-	(*v1.NotifyRequest)(nil),            // 8: scrabble.telegram.v1.NotifyRequest
+	(*CreateInvoiceCommand)(nil),        // 8: scrabble.botlink.v1.CreateInvoiceCommand
-	(*v1.SendToUserRequest)(nil),        // 9: scrabble.telegram.v1.SendToUserRequest
+	(*PreCheckoutRequest)(nil),          // 9: scrabble.botlink.v1.PreCheckoutRequest
-	(*v1.SendToGameChannelRequest)(nil), // 10: scrabble.telegram.v1.SendToGameChannelRequest
+	(*PreCheckoutResponse)(nil),         // 10: scrabble.botlink.v1.PreCheckoutResponse
+	(*ForwardPaymentRequest)(nil),       // 11: scrabble.botlink.v1.ForwardPaymentRequest
+	(*ForwardPaymentResponse)(nil),      // 12: scrabble.botlink.v1.ForwardPaymentResponse
+	(*v1.NotifyRequest)(nil),            // 13: scrabble.telegram.v1.NotifyRequest
+	(*v1.SendToUserRequest)(nil),        // 14: scrabble.telegram.v1.SendToUserRequest
+	(*v1.SendToGameChannelRequest)(nil), // 15: scrabble.telegram.v1.SendToGameChannelRequest
 }
 var file_botlink_v1_botlink_proto_depIdxs = []int32{
 	2,  // 0: scrabble.botlink.v1.FromBot.hello:type_name -> scrabble.botlink.v1.Hello
 	4,  // 1: scrabble.botlink.v1.FromBot.ack:type_name -> scrabble.botlink.v1.Ack
 	3,  // 2: scrabble.botlink.v1.ToBot.command:type_name -> scrabble.botlink.v1.Command
-	8,  // 3: scrabble.botlink.v1.Command.notify:type_name -> scrabble.telegram.v1.NotifyRequest
+	13, // 3: scrabble.botlink.v1.Command.notify:type_name -> scrabble.telegram.v1.NotifyRequest
-	9,  // 4: scrabble.botlink.v1.Command.send_to_user:type_name -> scrabble.telegram.v1.SendToUserRequest
+	14, // 4: scrabble.botlink.v1.Command.send_to_user:type_name -> scrabble.telegram.v1.SendToUserRequest
-	10, // 5: scrabble.botlink.v1.Command.send_to_channel:type_name -> scrabble.telegram.v1.SendToGameChannelRequest
+	15, // 5: scrabble.botlink.v1.Command.send_to_channel:type_name -> scrabble.telegram.v1.SendToGameChannelRequest
 	5,  // 6: scrabble.botlink.v1.Command.chat_gate:type_name -> scrabble.botlink.v1.ChatGateCommand
-	0,  // 7: scrabble.botlink.v1.BotLink.Link:input_type -> scrabble.botlink.v1.FromBot
+	8,  // 7: scrabble.botlink.v1.Command.create_invoice:type_name -> scrabble.botlink.v1.CreateInvoiceCommand
-	6,  // 8: scrabble.botlink.v1.BotLink.ResolveChatEligibility:input_type -> scrabble.botlink.v1.ChatEligibilityRequest
+	0,  // 8: scrabble.botlink.v1.BotLink.Link:input_type -> scrabble.botlink.v1.FromBot
-	1,  // 9: scrabble.botlink.v1.BotLink.Link:output_type -> scrabble.botlink.v1.ToBot
+	6,  // 9: scrabble.botlink.v1.BotLink.ResolveChatEligibility:input_type -> scrabble.botlink.v1.ChatEligibilityRequest
-	7,  // 10: scrabble.botlink.v1.BotLink.ResolveChatEligibility:output_type -> scrabble.botlink.v1.ChatEligibilityResponse
+	9,  // 10: scrabble.botlink.v1.BotLink.ValidatePreCheckout:input_type -> scrabble.botlink.v1.PreCheckoutRequest
-	9,  // [9:11] is the sub-list for method output_type
+	11, // 11: scrabble.botlink.v1.BotLink.ForwardPayment:input_type -> scrabble.botlink.v1.ForwardPaymentRequest
-	7,  // [7:9] is the sub-list for method input_type
+	1,  // 12: scrabble.botlink.v1.BotLink.Link:output_type -> scrabble.botlink.v1.ToBot
-	7,  // [7:7] is the sub-list for extension type_name
+	7,  // 13: scrabble.botlink.v1.BotLink.ResolveChatEligibility:output_type -> scrabble.botlink.v1.ChatEligibilityResponse
-	7,  // [7:7] is the sub-list for extension extendee
+	10, // 14: scrabble.botlink.v1.BotLink.ValidatePreCheckout:output_type -> scrabble.botlink.v1.PreCheckoutResponse
-	0,  // [0:7] is the sub-list for field type_name
+	12, // 15: scrabble.botlink.v1.BotLink.ForwardPayment:output_type -> scrabble.botlink.v1.ForwardPaymentResponse
+	12, // [12:16] is the sub-list for method output_type
+	8,  // [8:12] is the sub-list for method input_type
+	8,  // [8:8] is the sub-list for extension type_name
+	8,  // [8:8] is the sub-list for extension extendee
+	0,  // [0:8] is the sub-list for field type_name
 }
 
 func init() { file_botlink_v1_botlink_proto_init() }
@@ -666,6 +1033,7 @@ func file_botlink_v1_botlink_proto_init() {
 		(*Command_SendToUser)(nil),
 		(*Command_SendToChannel)(nil),
 		(*Command_ChatGate)(nil),
+		(*Command_CreateInvoice)(nil),
 	}
 	type x struct{}
 	out := protoimpl.TypeBuilder{
@@ -673,7 +1041,7 @@ func file_botlink_v1_botlink_proto_init() {
 			GoPackagePath: reflect.TypeOf(x{}).PkgPath(),
 			RawDescriptor: unsafe.Slice(unsafe.StringData(file_botlink_v1_botlink_proto_rawDesc), len(file_botlink_v1_botlink_proto_rawDesc)),
 			NumEnums:      0,
-			NumMessages:   8,
+			NumMessages:   13,
 			NumExtensions: 0,
 			NumServices:   1,
 		},

pkg/proto/botlink/v1/botlink.proto

@@ -27,6 +27,24 @@ service BotLink {
   // same mTLS channel when a user joins the chat, to decide whether to grant the
   // write permission. Delivery of the answer is request/response (not best-effort).
   rpc ResolveChatEligibility(ChatEligibilityRequest) returns (ChatEligibilityResponse);
+
+  // ValidatePreCheckout answers whether a Telegram Stars pre_checkout_query may be
+  // approved before any star is charged: the order in the invoice payload exists, is
+  // still creditable (pending or an honoured-expired order, never one already paid),
+  // and its amount and currency match the invoice. The bot calls it on every
+  // pre_checkout_query and approves only on ok; a not-ok answer or a channel failure
+  // declines the charge (fail-closed). Reusable Stars invoice links make this gate the
+  // one place a repeat payment is stopped before money moves. Request/response.
+  rpc ValidatePreCheckout(PreCheckoutRequest) returns (PreCheckoutResponse);
+
+  // ForwardPayment delivers a completed Telegram Stars payment from the bot's durable
+  // outbox to the gateway for crediting. The bot calls it (retrying until it gets a
+  // response) after Telegram confirms the payment; the gateway forwards it to the
+  // backend intake, which credits the order once, idempotent on
+  // telegram_payment_charge_id. A response means the payment was durably handled
+  // (credited, or recorded as unmatched) and the bot may forget the outbox row; a
+  // transport error leaves the row for a later retry. Request/response.
+  rpc ForwardPayment(ForwardPaymentRequest) returns (ForwardPaymentResponse);
 }
 
 // FromBot is a message the bot sends to the gateway: the opening Hello, then one
@@ -61,17 +79,21 @@ message Command {
     scrabble.telegram.v1.SendToUserRequest send_to_user = 3;
     scrabble.telegram.v1.SendToGameChannelRequest send_to_channel = 4;
     ChatGateCommand chat_gate = 5;
+    CreateInvoiceCommand create_invoice = 6;
   }
 }
 
 // Ack reports the outcome of the Command with command_id. delivered mirrors the
 // connector delivery semantics (false when the kind is not rendered out-of-app, the
 // user never started the bot, or no channel is configured); error carries an
-// unexpected transport/render failure, distinct from a clean not-delivered.
+// unexpected transport/render failure, distinct from a clean not-delivered. result
+// carries a command's return value when it has one (the created invoice link for a
+// create_invoice command); it is empty otherwise.
 message Ack {
   string command_id = 1;
   bool delivered = 2;
   string error = 3;
+  string result = 4;
 }
 
 // ChatGateCommand sets a Telegram user's write access in the moderated discussion
@@ -99,3 +121,48 @@ message ChatEligibilityResponse {
   bool registered = 1;
   bool eligible = 2;
 }
+
+// CreateInvoiceCommand asks the bot to mint a Telegram Stars invoice link for a
+// pending order (createInvoiceLink in XTR). payload is the order id, which Telegram
+// echoes back in the pre_checkout_query and the successful_payment; amount is the
+// price in whole stars; title and description are shown on the invoice. The bot
+// returns the link in its Ack result.
+message CreateInvoiceCommand {
+  string title = 1;
+  string description = 2;
+  string payload = 3;
+  int64 amount = 4;
+}
+
+// PreCheckoutRequest asks whether a Stars pre_checkout_query for order_id at amount
+// (whole stars) in currency may be approved before the charge.
+message PreCheckoutRequest {
+  string order_id = 1;
+  int64 amount = 2;
+  string currency = 3;
+}
+
+// PreCheckoutResponse is the approval answer. ok approves the charge; reason carries a
+// short user-facing decline message when ok is false.
+message PreCheckoutResponse {
+  bool ok = 1;
+  string reason = 2;
+}
+
+// ForwardPaymentRequest carries a completed Stars payment: order_id from the invoice
+// payload, the Telegram charge id (the idempotency key), the amount in whole stars,
+// and the payer's Telegram user id.
+message ForwardPaymentRequest {
+  string order_id = 1;
+  string telegram_payment_charge_id = 2;
+  int64 amount = 3;
+  int64 telegram_user_id = 4;
+}
+
+// ForwardPaymentResponse reports the durable outcome. credited is true when the order
+// was credited (or already had been); false means the payment was recorded but could
+// not be matched to a creditable order (an operator follows up). Either way the bot
+// may forget the outbox row — only a transport error triggers a retry.
+message ForwardPaymentResponse {
+  bool credited = 1;
+}

pkg/proto/botlink/v1/botlink_grpc.pb.go

@@ -28,6 +28,8 @@ const _ = grpc.SupportPackageIsVersion9
 const (
 	BotLink_Link_FullMethodName                   = "/scrabble.botlink.v1.BotLink/Link"
 	BotLink_ResolveChatEligibility_FullMethodName = "/scrabble.botlink.v1.BotLink/ResolveChatEligibility"
+	BotLink_ValidatePreCheckout_FullMethodName    = "/scrabble.botlink.v1.BotLink/ValidatePreCheckout"
+	BotLink_ForwardPayment_FullMethodName         = "/scrabble.botlink.v1.BotLink/ForwardPayment"
 )
 
 // BotLinkClient is the client API for BotLink service.
@@ -48,6 +50,22 @@ type BotLinkClient interface {
 	// same mTLS channel when a user joins the chat, to decide whether to grant the
 	// write permission. Delivery of the answer is request/response (not best-effort).
 	ResolveChatEligibility(ctx context.Context, in *ChatEligibilityRequest, opts ...grpc.CallOption) (*ChatEligibilityResponse, error)
+	// ValidatePreCheckout answers whether a Telegram Stars pre_checkout_query may be
+	// approved before any star is charged: the order in the invoice payload exists, is
+	// still creditable (pending or an honoured-expired order, never one already paid),
+	// and its amount and currency match the invoice. The bot calls it on every
+	// pre_checkout_query and approves only on ok; a not-ok answer or a channel failure
+	// declines the charge (fail-closed). Reusable Stars invoice links make this gate the
+	// one place a repeat payment is stopped before money moves. Request/response.
+	ValidatePreCheckout(ctx context.Context, in *PreCheckoutRequest, opts ...grpc.CallOption) (*PreCheckoutResponse, error)
+	// ForwardPayment delivers a completed Telegram Stars payment from the bot's durable
+	// outbox to the gateway for crediting. The bot calls it (retrying until it gets a
+	// response) after Telegram confirms the payment; the gateway forwards it to the
+	// backend intake, which credits the order once, idempotent on
+	// telegram_payment_charge_id. A response means the payment was durably handled
+	// (credited, or recorded as unmatched) and the bot may forget the outbox row; a
+	// transport error leaves the row for a later retry. Request/response.
+	ForwardPayment(ctx context.Context, in *ForwardPaymentRequest, opts ...grpc.CallOption) (*ForwardPaymentResponse, error)
 }
 
 type botLinkClient struct {
@@ -81,6 +99,26 @@ func (c *botLinkClient) ResolveChatEligibility(ctx context.Context, in *ChatElig
 	return out, nil
 }
 
+func (c *botLinkClient) ValidatePreCheckout(ctx context.Context, in *PreCheckoutRequest, opts ...grpc.CallOption) (*PreCheckoutResponse, error) {
+	cOpts := append([]grpc.CallOption{grpc.StaticMethod()}, opts...)
+	out := new(PreCheckoutResponse)
+	err := c.cc.Invoke(ctx, BotLink_ValidatePreCheckout_FullMethodName, in, out, cOpts...)
+	if err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
+func (c *botLinkClient) ForwardPayment(ctx context.Context, in *ForwardPaymentRequest, opts ...grpc.CallOption) (*ForwardPaymentResponse, error) {
+	cOpts := append([]grpc.CallOption{grpc.StaticMethod()}, opts...)
+	out := new(ForwardPaymentResponse)
+	err := c.cc.Invoke(ctx, BotLink_ForwardPayment_FullMethodName, in, out, cOpts...)
+	if err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
 // BotLinkServer is the server API for BotLink service.
 // All implementations must embed UnimplementedBotLinkServer
 // for forward compatibility.
@@ -99,6 +137,22 @@ type BotLinkServer interface {
 	// same mTLS channel when a user joins the chat, to decide whether to grant the
 	// write permission. Delivery of the answer is request/response (not best-effort).
 	ResolveChatEligibility(context.Context, *ChatEligibilityRequest) (*ChatEligibilityResponse, error)
+	// ValidatePreCheckout answers whether a Telegram Stars pre_checkout_query may be
+	// approved before any star is charged: the order in the invoice payload exists, is
+	// still creditable (pending or an honoured-expired order, never one already paid),
+	// and its amount and currency match the invoice. The bot calls it on every
+	// pre_checkout_query and approves only on ok; a not-ok answer or a channel failure
+	// declines the charge (fail-closed). Reusable Stars invoice links make this gate the
+	// one place a repeat payment is stopped before money moves. Request/response.
+	ValidatePreCheckout(context.Context, *PreCheckoutRequest) (*PreCheckoutResponse, error)
+	// ForwardPayment delivers a completed Telegram Stars payment from the bot's durable
+	// outbox to the gateway for crediting. The bot calls it (retrying until it gets a
+	// response) after Telegram confirms the payment; the gateway forwards it to the
+	// backend intake, which credits the order once, idempotent on
+	// telegram_payment_charge_id. A response means the payment was durably handled
+	// (credited, or recorded as unmatched) and the bot may forget the outbox row; a
+	// transport error leaves the row for a later retry. Request/response.
+	ForwardPayment(context.Context, *ForwardPaymentRequest) (*ForwardPaymentResponse, error)
 	mustEmbedUnimplementedBotLinkServer()
 }
 
@@ -115,6 +169,12 @@ func (UnimplementedBotLinkServer) Link(grpc.BidiStreamingServer[FromBot, ToBot])
 func (UnimplementedBotLinkServer) ResolveChatEligibility(context.Context, *ChatEligibilityRequest) (*ChatEligibilityResponse, error) {
 	return nil, status.Errorf(codes.Unimplemented, "method ResolveChatEligibility not implemented")
 }
+func (UnimplementedBotLinkServer) ValidatePreCheckout(context.Context, *PreCheckoutRequest) (*PreCheckoutResponse, error) {
+	return nil, status.Errorf(codes.Unimplemented, "method ValidatePreCheckout not implemented")
+}
+func (UnimplementedBotLinkServer) ForwardPayment(context.Context, *ForwardPaymentRequest) (*ForwardPaymentResponse, error) {
+	return nil, status.Errorf(codes.Unimplemented, "method ForwardPayment not implemented")
+}
 func (UnimplementedBotLinkServer) mustEmbedUnimplementedBotLinkServer() {}
 func (UnimplementedBotLinkServer) testEmbeddedByValue()                 {}
 
@@ -161,6 +221,42 @@ func _BotLink_ResolveChatEligibility_Handler(srv interface{}, ctx context.Contex
 	return interceptor(ctx, in, info, handler)
 }
 
+func _BotLink_ValidatePreCheckout_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
+	in := new(PreCheckoutRequest)
+	if err := dec(in); err != nil {
+		return nil, err
+	}
+	if interceptor == nil {
+		return srv.(BotLinkServer).ValidatePreCheckout(ctx, in)
+	}
+	info := &grpc.UnaryServerInfo{
+		Server:     srv,
+		FullMethod: BotLink_ValidatePreCheckout_FullMethodName,
+	}
+	handler := func(ctx context.Context, req interface{}) (interface{}, error) {
+		return srv.(BotLinkServer).ValidatePreCheckout(ctx, req.(*PreCheckoutRequest))
+	}
+	return interceptor(ctx, in, info, handler)
+}
+
+func _BotLink_ForwardPayment_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
+	in := new(ForwardPaymentRequest)
+	if err := dec(in); err != nil {
+		return nil, err
+	}
+	if interceptor == nil {
+		return srv.(BotLinkServer).ForwardPayment(ctx, in)
+	}
+	info := &grpc.UnaryServerInfo{
+		Server:     srv,
+		FullMethod: BotLink_ForwardPayment_FullMethodName,
+	}
+	handler := func(ctx context.Context, req interface{}) (interface{}, error) {
+		return srv.(BotLinkServer).ForwardPayment(ctx, req.(*ForwardPaymentRequest))
+	}
+	return interceptor(ctx, in, info, handler)
+}
+
 // BotLink_ServiceDesc is the grpc.ServiceDesc for BotLink service.
 // It's only intended for direct use with grpc.RegisterService,
 // and not to be introspected or modified (even as a copy)
@@ -172,6 +268,14 @@ var BotLink_ServiceDesc = grpc.ServiceDesc{
 			MethodName: "ResolveChatEligibility",
 			Handler:    _BotLink_ResolveChatEligibility_Handler,
 		},
+		{
+			MethodName: "ValidatePreCheckout",
+			Handler:    _BotLink_ValidatePreCheckout_Handler,
+		},
+		{
+			MethodName: "ForwardPayment",
+			Handler:    _BotLink_ForwardPayment_Handler,
+		},
 	},
 	Streams: []grpc.StreamDesc{
 		{

platform/telegram/README.md

@@ -91,6 +91,16 @@ Telegram identity to an account from a browser. Both map a rejection to gRPC
   the seeded Mini App rather than the bot profile.
 - **Rate limiting.** Outbound sends are throttled (`TELEGRAM_SEND_RATE_PER_SECOND`,
   default 25) to respect the Bot API flood limits.
+- **Payments (Telegram Stars).** When `TELEGRAM_STARS_OUTBOX_DIR` is set (default `/data`), the
+  bot handles the Stars rail. Only the bot reaches Telegram, so it mints the invoice on a
+  `CreateInvoice` bot-link command (`createInvoiceLink`, XTR — the link goes back to the Mini App
+  for `WebApp.openInvoice`); it gates each `pre_checkout_query` through the bot-link
+  (`ValidatePreCheckout`, backed by the backend intake — declining an already-paid reusable
+  invoice before the charge); and it records each `successful_payment` in a durable **SQLite
+  outbox** (`internal/outbox`, `stars.db` on the writable volume) before forwarding it over the
+  bot-link (`ForwardPayment`). The outbox is re-driven on startup and every 30 s, so a gateway or
+  backend outage never loses a paid order; crediting is idempotent on `telegram_payment_charge_id`.
+  The rail stays inert until a chip pack carries an XTR price (seeded in the admin).
 
 The send commands address a recipient by the identity `external_id` (as in the backend
 `identities` table), so a future VK / MAX bot reuses them; only the validator's initData
@@ -104,9 +114,11 @@ parsing is Telegram-specific.
   gateway also implements `SendToUser` / `SendToGameChannel` as the backend's admin
   relay.
 - `pkg/proto/botlink/v1`, service `BotLink` — the reverse bidi stream the **bot** dials
-  on the gateway (`Hello` / `Command` / `Ack`), now also carrying a `ChatGateCommand` (set
+  on the gateway (`Hello` / `Command` / `Ack`), carrying a `ChatGateCommand` (set a user's
-  a user's chat write access) and a unary `ResolveChatEligibility` (the bot's join-time
+  chat write access) and a `CreateInvoiceCommand` (mint a Stars invoice link, returned in the
-  query) over the same mTLS channel. Generated Go is committed under `pkg`.
+  Ack result), plus unary `ResolveChatEligibility` (the bot's join-time query),
+  `ValidatePreCheckout` and `ForwardPayment` (the Stars rail) over the same mTLS channel.
+  Generated Go is committed under `pkg`.
 
 ## Deep-link scheme
 
@@ -153,6 +165,7 @@ Bot (`cmd/bot`):
 | `TELEGRAM_CHAT_ID` | — | the moderated discussion chat id (a channel's linked group); empty disables chat gating |
 | `TELEGRAM_SUPPORT_CHAT_ID` | — | the support relay's forum supergroup id (topic per user); empty disables the relay |
 | `TELEGRAM_SUPPORT_STATE_DIR` | `/data` | directory for the support relay's JSON state (a writable volume) |
+| `TELEGRAM_STARS_OUTBOX_DIR` | `/data` | directory for the Telegram Stars payment outbox (`stars.db`, a writable volume); empty disables the Stars rail |
 | `TELEGRAM_PROMO_BOT_TOKEN` | — | the optional standalone promo bot's token; empty disables it |
 | `TELEGRAM_BOT_USERNAME` | — | the main bot's @username without the @ (promo message); required when the promo bot runs |
 | `TELEGRAM_BOT_LINK` | — | the main bot's Mini App link for the promo button (the UI's `VITE_TELEGRAM_LINK`); required when the promo bot runs |

platform/telegram/cmd/bot/main.go

@@ -23,6 +23,7 @@ import (
 	"scrabble/platform/telegram/internal/bot"
 	"scrabble/platform/telegram/internal/botlink"
 	"scrabble/platform/telegram/internal/config"
+	"scrabble/platform/telegram/internal/outbox"
 	"scrabble/platform/telegram/internal/promobot"
 	"scrabble/platform/telegram/internal/support"
 )
@@ -90,11 +91,24 @@ func run(ctx context.Context, cfg config.BotConfig, logger *zap.Logger) error {
 		GameChannelID:     cfg.GameChannelID,
 		SupportChatID:     cfg.SupportChatID,
 		SupportStore:      supportStore,
+		AcceptPayments:    cfg.StarsOutboxDir != "",
 	}, logger)
 	if err != nil {
 		return err
 	}
 
+	// The Telegram Stars payment outbox: a durable SQLite store on the bot host's writable volume.
+	// Opened when the rail is enabled; a failure to open is fatal, since accepting Stars without a
+	// durable outbox would risk losing a paid-for order.
+	var paymentOutbox *outbox.Store
+	if cfg.StarsOutboxDir != "" {
+		paymentOutbox, err = outbox.Open(filepath.Join(cfg.StarsOutboxDir, "stars.db"))
+		if err != nil {
+			return err
+		}
+		defer func() { _ = paymentOutbox.Close() }()
+	}
+
 	tlsCfg, err := mtls.ClientConfig(cfg.BotLink.CertFile, cfg.BotLink.KeyFile, cfg.BotLink.CAFile, cfg.BotLink.ServerName)
 	if err != nil {
 		return err
@@ -115,6 +129,12 @@ func run(ctx context.Context, cfg config.BotConfig, logger *zap.Logger) error {
 	// the bot after the client is built — the late binding that breaks the bot <->
 	// client construction cycle.
 	b.SetEligibilityResolver(client.ResolveChatEligibility)
+	// The Telegram Stars payment path rides the same bot-link: pre_checkout validation and
+	// completed-payment forwarding, backed by the durable outbox — wired here for the same
+	// late-binding reason.
+	if paymentOutbox != nil {
+		b.SetPaymentHandlers(client.ValidatePreCheckout, client.ForwardPayment, paymentOutbox)
+	}
 
 	// The optional standalone promo bot: a second bot (its own token) that only answers
 	// /start with a button opening the main bot's Mini App. It is self-contained — no
@@ -160,6 +180,11 @@ func run(ctx context.Context, cfg config.BotConfig, logger *zap.Logger) error {
 			logger.Error("bot-link client stopped", zap.Error(err))
 		}
 	})
+	// Re-drive the Stars payment outbox: at startup (recovering payments left by a restart or a past
+	// outage) and periodically thereafter.
+	if paymentOutbox != nil {
+		wg.Go(func() { b.RunPaymentDrainer(ctx) })
+	}
 	// The promo bot runs its own getUpdates long-poll on its own token (no 409 with
 	// the main bot's lease).
 	if promo != nil {

platform/telegram/go.mod

@@ -12,3 +12,16 @@ require (
 	google.golang.org/protobuf v1.36.11
 	scrabble/pkg v0.0.0
 )
+
+require (
+	github.com/dustin/go-humanize v1.0.1 // indirect
+	github.com/google/uuid v1.6.0 // indirect
+	github.com/mattn/go-isatty v0.0.20 // indirect
+	github.com/ncruces/go-strftime v1.0.0 // indirect
+	github.com/remyoudompheng/bigfft v0.0.0-20230129092748-24d4a6f8daec // indirect
+	golang.org/x/sys v0.43.0 // indirect
+	modernc.org/libc v1.72.0 // indirect
+	modernc.org/mathutil v1.7.1 // indirect
+	modernc.org/memory v1.11.0 // indirect
+	modernc.org/sqlite v1.49.1 // indirect
+)

platform/telegram/internal/bot/bot.go

@@ -16,6 +16,7 @@ import (
 	"go.uber.org/zap"
 	"golang.org/x/time/rate"
 
+	"scrabble/platform/telegram/internal/outbox"
 	"scrabble/platform/telegram/internal/support"
 )
 
@@ -49,6 +50,10 @@ type Config struct {
 	// SupportStore persists the support relay's state (topic mapping, block list,
 	// relayed message ids); required when SupportChatID is set, ignored otherwise.
 	SupportStore *support.Store
+	// AcceptPayments enables the Telegram Stars rail: the bot then subscribes to
+	// pre_checkout_query updates and handles pre_checkout / successful_payment. The runtime
+	// dependencies (the validator, forwarder and outbox) are wired with SetPaymentHandlers.
+	AcceptPayments bool
 }
 
 // EligibilityResolver answers whether the Telegram user identified by externalID
@@ -91,6 +96,12 @@ type Bot struct {
 	supportLocks *keyedMutex
 	// admins caches the support chat's administrator ids (who may reply and act).
 	admins *adminCache
+	// precheck validates a Stars pre_checkout order and forward delivers a completed payment; both
+	// are late-bound (SetPaymentHandlers) over the bot-link, which is built after the bot. outbox
+	// durably records completed payments before they are forwarded. All nil when the Stars rail is off.
+	precheck PreCheckoutValidator
+	forward  PaymentForwarder
+	outbox   *outbox.Store
 }
 
 // New builds the bot wrapper, registering the /start handler and a default handler
@@ -123,9 +134,10 @@ func New(cfg Config, log *zap.Logger) (*Bot, error) {
 		// callback handler by their "sup:" data prefix.
 		opts = append(opts, tgbot.WithCallbackQueryDataHandler(supportCallbackPrefix, tgbot.MatchTypePrefix, t.handleSupportCallback))
 	}
-	// Allowed updates default to "all except chat_member". Specify an explicit set only
+	// Allowed updates default to "all except chat_member" (which already includes
-	// when we need chat_member (moderated chat) — and then re-add callback_query (which
+	// pre_checkout_query and message-borne successful_payment). Specify an explicit set only when we
-	// the explicit set would otherwise drop) when the support relay needs it.
+	// need chat_member (moderated chat) — and then re-add callback_query and, for the Stars rail,
+	// pre_checkout_query, which the explicit set would otherwise drop.
 	if cfg.ChatID != 0 {
 		allowed := tgbot.AllowedUpdates{
 			models.AllowedUpdateMessage,
@@ -135,6 +147,9 @@ func New(cfg Config, log *zap.Logger) (*Bot, error) {
 		if t.supportEnabled() {
 			allowed = append(allowed, models.AllowedUpdateCallbackQuery)
 		}
+		if cfg.AcceptPayments {
+			allowed = append(allowed, models.AllowedUpdatePreCheckoutQuery)
+		}
 		opts = append(opts, tgbot.WithAllowedUpdates(allowed))
 	}
 	if cfg.TestEnv {
@@ -346,6 +361,17 @@ func (t *Bot) handleUpdate(ctx context.Context, api *tgbot.Bot, update *models.U
 		t.handleChatMember(ctx, update.ChatMember)
 		return
 	}
+	// Telegram Stars: the pre_checkout gate (validated against the backend) and the completed
+	// payment (persisted to the outbox and forwarded) — before the support relay, so a payment
+	// message is never mistaken for a support DM or given a launch reply.
+	if update.PreCheckoutQuery != nil {
+		t.handlePreCheckout(ctx, update.PreCheckoutQuery)
+		return
+	}
+	if update.Message != nil && update.Message.SuccessfulPayment != nil {
+		t.handleSuccessfulPayment(ctx, update.Message)
+		return
+	}
 	// Support relay (when enabled): a non-/start message — /start has its own handler —
 	// is either an operator's reply in the support chat or a user's direct message to
 	// relay. Everything else falls through to the Mini App launch reply.

platform/telegram/internal/bot/payments.go

@@ -0,0 +1,166 @@
+package bot
+
+import (
+	"context"
+	"time"
+
+	tgbot "github.com/go-telegram/bot"
+	"github.com/go-telegram/bot/models"
+	"go.uber.org/zap"
+
+	"scrabble/platform/telegram/internal/outbox"
+)
+
+// starsCurrency is the Telegram Stars currency code for createInvoiceLink and the invoice line.
+const starsCurrency = "XTR"
+
+// paymentDrainInterval is how often the bot re-drives undelivered outbox payments (the backstop for a
+// gateway or backend outage, and the restart re-drive); the happy path forwards immediately on receipt.
+const paymentDrainInterval = 30 * time.Second
+
+// PreCheckoutValidator validates a Stars pre_checkout order over the bot-link and returns whether it
+// may be charged plus a short, already-localised decline reason for the payer. The bot-link client
+// backs it.
+type PreCheckoutValidator func(ctx context.Context, orderID string, amount int64, currency string) (ok bool, reason string, err error)
+
+// PaymentForwarder delivers a completed Stars payment over the bot-link for crediting and reports
+// whether it was credited (or already had been). A non-nil error is transient and retried. The
+// bot-link client backs it.
+type PaymentForwarder func(ctx context.Context, orderID, chargeID string, amount, telegramUserID int64) (credited bool, err error)
+
+// SetPaymentHandlers wires the Telegram Stars runtime dependencies after construction: the
+// pre_checkout validator and payment forwarder (both over the bot-link, built after the bot) and the
+// durable outbox. It is the late binding that breaks the bot <-> bot-link construction cycle.
+func (t *Bot) SetPaymentHandlers(precheck PreCheckoutValidator, forward PaymentForwarder, store *outbox.Store) {
+	t.precheck = precheck
+	t.forward = forward
+	t.outbox = store
+}
+
+// CreateInvoiceLink mints a Telegram Stars invoice link (XTR) for amountStars, tagged with payload
+// (the order id, echoed back in pre_checkout and successful_payment), and returns the link. The
+// provider token is empty for Stars. Only the bot reaches Telegram, so the gateway calls this over
+// the bot-link on the wallet-order path.
+func (t *Bot) CreateInvoiceLink(ctx context.Context, title, description, payload string, amountStars int64) (string, error) {
+	return t.api.CreateInvoiceLink(ctx, &tgbot.CreateInvoiceLinkParams{
+		Title:       title,
+		Description: description,
+		Payload:     payload,
+		Currency:    starsCurrency,
+		Prices:      []models.LabeledPrice{{Label: title, Amount: int(amountStars)}},
+	})
+}
+
+// handlePreCheckout answers a Stars pre_checkout_query. It validates the order against the backend
+// (over the bot-link) and approves only on a positive answer; a not-ok answer or a validation
+// failure declines the charge (fail-closed), before any star moves. The decline reason from the
+// backend is already localised to the payer's account language.
+func (t *Bot) handlePreCheckout(ctx context.Context, q *models.PreCheckoutQuery) {
+	ok, reason := false, ""
+	if t.precheck == nil {
+		t.log.Warn("pre_checkout received but the validator is not wired; declining", zap.String("order", q.InvoicePayload))
+		reason = fallbackDeclineText(q.From)
+	} else if v, r, err := t.precheck(ctx, q.InvoicePayload, int64(q.TotalAmount), q.Currency); err != nil {
+		t.log.Warn("pre_checkout validation failed; declining", zap.String("order", q.InvoicePayload), zap.Error(err))
+		reason = fallbackDeclineText(q.From)
+	} else {
+		ok, reason = v, r
+	}
+	params := &tgbot.AnswerPreCheckoutQueryParams{PreCheckoutQueryID: q.ID, OK: ok}
+	if !ok {
+		params.ErrorMessage = reason
+	}
+	if _, err := t.api.AnswerPreCheckoutQuery(ctx, params); err != nil {
+		t.log.Warn("answer pre_checkout failed", zap.String("order", q.InvoicePayload), zap.Error(err))
+	}
+}
+
+// handleSuccessfulPayment records a completed Stars payment in the durable outbox and forwards it to
+// the gateway. Persisting first is the durability point: a crash before forwarding still re-drives
+// the payment on restart. The immediate forward is best-effort; the periodic drainer covers a
+// gateway or backend outage.
+func (t *Bot) handleSuccessfulPayment(ctx context.Context, msg *models.Message) {
+	sp := msg.SuccessfulPayment
+	if t.outbox == nil {
+		t.log.Error("successful_payment received but the outbox is not wired; the payment is at risk",
+			zap.String("charge", sp.TelegramPaymentChargeID))
+		return
+	}
+	var tgUserID int64
+	if msg.From != nil {
+		tgUserID = msg.From.ID
+	}
+	rec := outbox.Record{
+		ChargeID: sp.TelegramPaymentChargeID,
+		OrderID:  sp.InvoicePayload,
+		Amount:   int64(sp.TotalAmount),
+		UserID:   tgUserID,
+	}
+	if err := t.outbox.Add(ctx, rec); err != nil {
+		t.log.Error("outbox persist failed; the drainer cannot recover this payment",
+			zap.String("charge", rec.ChargeID), zap.Error(err))
+		return
+	}
+	t.log.Info("stars payment received", zap.String("charge", rec.ChargeID), zap.String("order", rec.OrderID))
+	t.forwardOne(ctx, rec)
+}
+
+// RunPaymentDrainer re-drives undelivered outbox payments: once at startup (recovering any left by a
+// restart or a past outage) and then on paymentDrainInterval, until ctx is cancelled. It is a no-op
+// when the Stars rail is not wired.
+func (t *Bot) RunPaymentDrainer(ctx context.Context) {
+	if t.outbox == nil || t.forward == nil {
+		return
+	}
+	t.drainOutbox(ctx)
+	ticker := time.NewTicker(paymentDrainInterval)
+	defer ticker.Stop()
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case <-ticker.C:
+			t.drainOutbox(ctx)
+		}
+	}
+}
+
+// drainOutbox forwards a batch of pending payments to the gateway.
+func (t *Bot) drainOutbox(ctx context.Context) {
+	recs, err := t.outbox.Pending(ctx, 50)
+	if err != nil {
+		t.log.Warn("outbox drain read failed", zap.Error(err))
+		return
+	}
+	for _, rec := range recs {
+		t.forwardOne(ctx, rec)
+	}
+}
+
+// forwardOne delivers one payment to the gateway and, on a durable response (credited or not), marks
+// it forwarded so it is not re-sent. A transport error leaves the row for the next drain. Crediting is
+// idempotent at the backend, so a re-forward after a lost ack never double-credits.
+func (t *Bot) forwardOne(ctx context.Context, rec outbox.Record) {
+	if t.forward == nil {
+		return
+	}
+	credited, err := t.forward(ctx, rec.OrderID, rec.ChargeID, rec.Amount, rec.UserID)
+	if err != nil {
+		t.log.Warn("forward payment failed; will retry", zap.String("charge", rec.ChargeID), zap.Error(err))
+		return
+	}
+	if err := t.outbox.MarkForwarded(ctx, rec.ChargeID); err != nil {
+		t.log.Error("mark forwarded failed", zap.String("charge", rec.ChargeID), zap.Error(err))
+		return
+	}
+	t.log.Info("stars payment forwarded", zap.String("charge", rec.ChargeID), zap.String("order", rec.OrderID), zap.Bool("credited", credited))
+}
+
+// fallbackDeclineText is the pre_checkout decline message used only when the backend cannot be
+// reached to form a localised one; it falls back to the payer's Telegram client language.
+func fallbackDeclineText(from *models.User) string {
+	if from != nil && from.LanguageCode == "ru" {
+		return "Оплата временно недоступна. Попробуйте позже."
+	}
+	return "Payment is temporarily unavailable. Please try again later."
+}

platform/telegram/internal/botlink/client.go

@@ -83,6 +83,34 @@ func (c *Client) ResolveChatEligibility(ctx context.Context, externalID string)
 	return resp.GetEligible(), nil
 }
 
+// ValidatePreCheckout asks the gateway whether a Telegram Stars pre_checkout_query for orderID
+// paying amount in currency may be approved, before the charge. The bot calls it on every
+// pre_checkout_query over the same mTLS connection and approves only on ok; the reason is a short
+// decline message (already localised by the backend) to show the payer.
+func (c *Client) ValidatePreCheckout(ctx context.Context, orderID string, amount int64, currency string) (ok bool, reason string, err error) {
+	resp, err := c.client.ValidatePreCheckout(ctx, &botlinkv1.PreCheckoutRequest{OrderId: orderID, Amount: amount, Currency: currency})
+	if err != nil {
+		return false, "", err
+	}
+	return resp.GetOk(), resp.GetReason(), nil
+}
+
+// ForwardPayment delivers a completed Stars payment to the gateway for crediting. The bot calls it
+// from the outbox drain; it reports whether the order was credited (or already had been). A non-nil
+// error is a transient failure the bot retries.
+func (c *Client) ForwardPayment(ctx context.Context, orderID, chargeID string, amount, telegramUserID int64) (credited bool, err error) {
+	resp, err := c.client.ForwardPayment(ctx, &botlinkv1.ForwardPaymentRequest{
+		OrderId:                 orderID,
+		TelegramPaymentChargeId: chargeID,
+		Amount:                  amount,
+		TelegramUserId:          telegramUserID,
+	})
+	if err != nil {
+		return false, err
+	}
+	return resp.GetCredited(), nil
+}
+
 // Run keeps the bot-link command stream open, re-opening it after each break, until
 // ctx is cancelled. The gRPC connection auto-reconnects the transport underneath.
 func (c *Client) Run(ctx context.Context) error {
@@ -121,8 +149,8 @@ func (c *Client) serve(ctx context.Context, client botlinkv1.BotLinkClient) erro
 		if cmd == nil {
 			continue
 		}
-		delivered, herr := c.exec.Handle(ctx, cmd)
+		delivered, result, herr := c.exec.Handle(ctx, cmd)
-		ack := &botlinkv1.Ack{CommandId: cmd.GetCommandId(), Delivered: delivered}
+		ack := &botlinkv1.Ack{CommandId: cmd.GetCommandId(), Delivered: delivered, Result: result}
 		if herr != nil {
 			ack.Error = herr.Error()
 		}

platform/telegram/internal/botlink/executor.go

@@ -27,6 +27,10 @@ type Sender interface {
 	// chat, but only when they are currently in it; it reports whether a restriction
 	// was applied.
 	ApplyChatGate(ctx context.Context, userID int64, allow bool) (bool, error)
+	// CreateInvoiceLink mints a Telegram Stars invoice link (XTR) for amountStars, tagged
+	// with payload (the order id, echoed back in pre_checkout and successful_payment), and
+	// returns the link.
+	CreateInvoiceLink(ctx context.Context, title, description, payload string, amountStars int64) (string, error)
 }
 
 // Executor turns a bot-link Command into a Bot API send. The delivered flag mirrors
@@ -48,22 +52,42 @@ func NewExecutor(sender Sender, channelID int64, log *zap.Logger) *Executor {
 	return &Executor{sender: sender, channelID: channelID, log: log}
 }
 
-// Handle dispatches one command to the matching Bot API send.
+// Handle dispatches one command to the matching Bot API call. It returns whether the command was
-func (e *Executor) Handle(ctx context.Context, cmd *botlinkv1.Command) (bool, error) {
+// delivered, an optional result string (the created invoice link for a create_invoice command; empty
+// otherwise), and an error for an unexpected or malformed failure.
+func (e *Executor) Handle(ctx context.Context, cmd *botlinkv1.Command) (bool, string, error) {
 	switch p := cmd.GetPayload().(type) {
 	case *botlinkv1.Command_Notify:
-		return e.notify(ctx, p.Notify)
+		d, err := e.notify(ctx, p.Notify)
+		return d, "", err
 	case *botlinkv1.Command_SendToUser:
-		return e.sendToUser(ctx, p.SendToUser)
+		d, err := e.sendToUser(ctx, p.SendToUser)
+		return d, "", err
 	case *botlinkv1.Command_SendToChannel:
-		return e.sendToChannel(ctx, p.SendToChannel)
+		d, err := e.sendToChannel(ctx, p.SendToChannel)
+		return d, "", err
 	case *botlinkv1.Command_ChatGate:
-		return e.chatGate(ctx, p.ChatGate)
+		d, err := e.chatGate(ctx, p.ChatGate)
+		return d, "", err
+	case *botlinkv1.Command_CreateInvoice:
+		return e.createInvoice(ctx, p.CreateInvoice)
 	default:
-		return false, fmt.Errorf("botlink: empty command")
+		return false, "", fmt.Errorf("botlink: empty command")
 	}
 }
 
+// createInvoice mints a Telegram Stars invoice link for the order and returns it in the Ack result.
+// A Bot API failure is a hard error carried back in the Ack, so the gateway's synchronous mint fails
+// (rather than returning an empty link).
+func (e *Executor) createInvoice(ctx context.Context, req *botlinkv1.CreateInvoiceCommand) (bool, string, error) {
+	link, err := e.sender.CreateInvoiceLink(ctx, req.GetTitle(), req.GetDescription(), req.GetPayload(), req.GetAmount())
+	if err != nil {
+		e.log.Warn("create invoice link failed", zap.String("order", req.GetPayload()), zap.Error(err))
+		return false, "", err
+	}
+	return true, link, nil
+}
+
 // chatGate applies a chat-gate command: it parses the target Telegram user id and
 // sets their write access in the moderated chat (a no-op when they are not in it). A
 // Bot API failure is logged and reported as not-delivered, not a hard error.

platform/telegram/internal/botlink/executor_test.go

@@ -16,6 +16,8 @@ type fakeSender struct {
 	notify      []notifyCall
 	text        []textCall
 	gate        []gateCall
+	invoice     []invoiceCall
+	invoiceLink string // CreateInvoiceLink's returned link
 	applied     bool   // ApplyChatGate's reported result
 	err         error
 }
@@ -32,6 +34,10 @@ type gateCall struct {
 	userID int64
 	allow  bool
 }
+type invoiceCall struct {
+	title, description, payload string
+	amount                      int64
+}
 
 func (f *fakeSender) Notify(_ context.Context, chatID int64, text, buttonText, startParam string) error {
 	f.notify = append(f.notify, notifyCall{chatID, text, buttonText, startParam})
@@ -48,6 +54,11 @@ func (f *fakeSender) ApplyChatGate(_ context.Context, userID int64, allow bool)
 	return f.applied, f.err
 }
 
+func (f *fakeSender) CreateInvoiceLink(_ context.Context, title, description, payload string, amountStars int64) (string, error) {
+	f.invoice = append(f.invoice, invoiceCall{title, description, payload, amountStars})
+	return f.invoiceLink, f.err
+}
+
 func yourTurnPayload(gameID string) []byte {
 	b := flatbuffers.NewBuilder(0)
 	gid := b.CreateString(gameID)
@@ -67,7 +78,7 @@ func TestExecutorNotifyDelivers(t *testing.T) {
 	const gameID = "7c9e6679-7425-40de-944b-e07fc1f90ae7"
 	sender := &fakeSender{}
 	exec := NewExecutor(sender, 0, nil)
-	delivered, err := exec.Handle(context.Background(), notifyCmd("12345", "your_turn", yourTurnPayload(gameID), "en"))
+	delivered, _, err := exec.Handle(context.Background(), notifyCmd("12345", "your_turn", yourTurnPayload(gameID), "en"))
 	if err != nil {
 		t.Fatalf("handle: %v", err)
 	}
@@ -85,7 +96,7 @@ func TestExecutorNotifyDelivers(t *testing.T) {
 func TestExecutorNotifySkipsUnrenderedKind(t *testing.T) {
 	sender := &fakeSender{}
 	exec := NewExecutor(sender, 0, nil)
-	delivered, err := exec.Handle(context.Background(), notifyCmd("12345", "opponent_moved", nil, "en"))
+	delivered, _, err := exec.Handle(context.Background(), notifyCmd("12345", "opponent_moved", nil, "en"))
 	if err != nil {
 		t.Fatalf("handle: %v", err)
 	}
@@ -99,7 +110,7 @@ func TestExecutorNotifySkipsUnrenderedKind(t *testing.T) {
 
 func TestExecutorNotifyInvalidExternalID(t *testing.T) {
 	exec := NewExecutor(&fakeSender{}, 0, nil)
-	if _, err := exec.Handle(context.Background(), notifyCmd("not-a-number", "your_turn", yourTurnPayload("g"), "en")); err == nil {
+	if _, _, err := exec.Handle(context.Background(), notifyCmd("not-a-number", "your_turn", yourTurnPayload("g"), "en")); err == nil {
 		t.Error("expected an error for a non-numeric external_id")
 	}
 }
@@ -108,7 +119,7 @@ func TestExecutorSendToUser(t *testing.T) {
 	sender := &fakeSender{}
 	exec := NewExecutor(sender, 0, nil)
 	cmd := &botlinkv1.Command{Payload: &botlinkv1.Command_SendToUser{SendToUser: &telegramv1.SendToUserRequest{ExternalId: "999", Text: "hi"}}}
-	delivered, err := exec.Handle(context.Background(), cmd)
+	delivered, _, err := exec.Handle(context.Background(), cmd)
 	if err != nil {
 		t.Fatalf("handle: %v", err)
 	}
@@ -126,7 +137,7 @@ func chatGateCmd(externalID string, allow bool) *botlinkv1.Command {
 func TestExecutorChatGateApplied(t *testing.T) {
 	sender := &fakeSender{applied: true}
 	exec := NewExecutor(sender, 0, nil)
-	delivered, err := exec.Handle(context.Background(), chatGateCmd("777", true))
+	delivered, _, err := exec.Handle(context.Background(), chatGateCmd("777", true))
 	if err != nil {
 		t.Fatalf("handle: %v", err)
 	}
@@ -138,7 +149,7 @@ func TestExecutorChatGateApplied(t *testing.T) {
 func TestExecutorChatGateNotInChat(t *testing.T) {
 	sender := &fakeSender{applied: false} // user not in the chat
 	exec := NewExecutor(sender, 0, nil)
-	delivered, err := exec.Handle(context.Background(), chatGateCmd("888", false))
+	delivered, _, err := exec.Handle(context.Background(), chatGateCmd("888", false))
 	if err != nil {
 		t.Fatalf("handle: %v", err)
 	}
@@ -152,24 +163,53 @@ func TestExecutorChatGateNotInChat(t *testing.T) {
 
 func TestExecutorChatGateInvalidExternalID(t *testing.T) {
 	exec := NewExecutor(&fakeSender{}, 0, nil)
-	if _, err := exec.Handle(context.Background(), chatGateCmd("not-a-number", true)); err == nil {
+	if _, _, err := exec.Handle(context.Background(), chatGateCmd("not-a-number", true)); err == nil {
 		t.Error("expected an error for a non-numeric external_id")
 	}
 }
 
+func TestExecutorCreateInvoice(t *testing.T) {
+	sender := &fakeSender{invoiceLink: "https://t.me/$abc"}
+	exec := NewExecutor(sender, 0, nil)
+	cmd := &botlinkv1.Command{Payload: &botlinkv1.Command_CreateInvoice{CreateInvoice: &botlinkv1.CreateInvoiceCommand{
+		Title: "50 chips", Description: "50 chips", Payload: "order-1", Amount: 40,
+	}}}
+	delivered, result, err := exec.Handle(context.Background(), cmd)
+	if err != nil {
+		t.Fatalf("handle: %v", err)
+	}
+	if !delivered || result != "https://t.me/$abc" {
+		t.Errorf("create invoice = %v / %q, want true / the link", delivered, result)
+	}
+	if len(sender.invoice) != 1 || sender.invoice[0].payload != "order-1" || sender.invoice[0].amount != 40 {
+		t.Errorf("invoice calls = %+v", sender.invoice)
+	}
+}
+
+func TestExecutorCreateInvoiceError(t *testing.T) {
+	sender := &fakeSender{err: context.DeadlineExceeded}
+	exec := NewExecutor(sender, 0, nil)
+	cmd := &botlinkv1.Command{Payload: &botlinkv1.Command_CreateInvoice{CreateInvoice: &botlinkv1.CreateInvoiceCommand{
+		Title: "x", Description: "x", Payload: "order-2", Amount: 10,
+	}}}
+	if _, _, err := exec.Handle(context.Background(), cmd); err == nil {
+		t.Error("expected an error when minting the invoice fails")
+	}
+}
+
 func TestExecutorSendToChannel(t *testing.T) {
 	channelCmd := &botlinkv1.Command{Payload: &botlinkv1.Command_SendToChannel{SendToChannel: &telegramv1.SendToGameChannelRequest{Text: "news"}}}
 
 	t.Run("unconfigured", func(t *testing.T) {
 		exec := NewExecutor(&fakeSender{}, 0, nil)
-		if _, err := exec.Handle(context.Background(), channelCmd); err == nil {
+		if _, _, err := exec.Handle(context.Background(), channelCmd); err == nil {
 			t.Error("expected an error when no channel is configured")
 		}
 	})
 	t.Run("configured", func(t *testing.T) {
 		sender := &fakeSender{}
 		exec := NewExecutor(sender, 555, nil)
-		delivered, err := exec.Handle(context.Background(), channelCmd)
+		delivered, _, err := exec.Handle(context.Background(), channelCmd)
 		if err != nil {
 			t.Fatalf("handle: %v", err)
 		}

platform/telegram/internal/config/config.go

@@ -52,6 +52,11 @@ type BotConfig struct {
 	// (TELEGRAM_SUPPORT_STATE_DIR, default /data). It must be writable by the
 	// container user (UID 65532) and backed by a persistent volume.
 	SupportStateDir string
+	// StarsOutboxDir is the directory holding the Telegram Stars payment outbox SQLite file
+	// (TELEGRAM_STARS_OUTBOX_DIR, optional; empty disables the Stars rail). It must be writable by
+	// the container user (UID 65532) and backed by a persistent volume — a lost outbox loses any
+	// payment not yet forwarded to the gateway.
+	StarsOutboxDir string
 	// PromoBotToken is the API token of the optional standalone promo bot run in this
 	// container — a second bot whose only job is to answer /start with a button that
 	// opens the main bot's Mini App (TELEGRAM_PROMO_BOT_TOKEN, optional; empty disables
@@ -157,6 +162,7 @@ func LoadBot() (BotConfig, error) {
 		BotLinkURL:        os.Getenv("TELEGRAM_BOT_LINK"),
 		PromoStartParam:   envOr("TELEGRAM_PROMO_START_PARAM", defaultPromoStartParam),
 		SupportStateDir:   envOr("TELEGRAM_SUPPORT_STATE_DIR", "/data"),
+		StarsOutboxDir:    os.Getenv("TELEGRAM_STARS_OUTBOX_DIR"),
 		LogLevel:          envOr("TELEGRAM_LOG_LEVEL", "info"),
 		BotLink: BotLinkClientConfig{
 			GatewayAddr: os.Getenv("TELEGRAM_GATEWAY_ADDR"),

platform/telegram/internal/outbox/store.go

@@ -0,0 +1,104 @@
+// Package outbox is the Telegram Stars payment outbox: a small SQLite store on the bot host's
+// writable volume that durably records each completed Stars payment the moment Telegram delivers it,
+// so a gateway or backend outage cannot lose it. The bot forwards pending rows to the gateway and
+// marks them delivered; rows still undelivered are re-driven on restart. It is pure-Go SQLite
+// (modernc.org/sqlite, no CGO) so it runs on the distroless image.
+package outbox
+
+import (
+	"context"
+	"database/sql"
+	"fmt"
+	"time"
+
+	_ "modernc.org/sqlite"
+)
+
+// Record is one completed Stars payment awaiting delivery to the gateway.
+type Record struct {
+	// ChargeID is the telegram_payment_charge_id — the primary key here and the credit idempotency
+	// key at the backend, so a re-delivered or retried payment is never credited twice.
+	ChargeID string
+	// OrderID is the invoice payload (our order id) the payment settles.
+	OrderID string
+	// Amount is the stars paid (the XTR minor unit is the whole star).
+	Amount int64
+	// UserID is the payer's Telegram user id.
+	UserID int64
+}
+
+// Store is the SQLite-backed payment outbox.
+type Store struct {
+	db *sql.DB
+}
+
+// Open opens (creating if absent) the outbox database at path and ensures its schema. The parent
+// directory must exist and be writable by the container user.
+func Open(path string) (*Store, error) {
+	db, err := sql.Open("sqlite", path)
+	if err != nil {
+		return nil, fmt.Errorf("outbox: open %s: %w", path, err)
+	}
+	// A single connection serialises writes and sidesteps SQLite's "database is locked" under the
+	// bot's low, bursty payment volume.
+	db.SetMaxOpenConns(1)
+	if _, err := db.Exec(`CREATE TABLE IF NOT EXISTS stars_payments (
+		charge_id  TEXT PRIMARY KEY,
+		order_id   TEXT NOT NULL,
+		amount     INTEGER NOT NULL,
+		user_id    INTEGER NOT NULL,
+		created_at INTEGER NOT NULL,
+		forwarded  INTEGER NOT NULL DEFAULT 0
+	)`); err != nil {
+		_ = db.Close()
+		return nil, fmt.Errorf("outbox: init schema: %w", err)
+	}
+	return &Store{db: db}, nil
+}
+
+// Close closes the database.
+func (s *Store) Close() error { return s.db.Close() }
+
+// Add records a completed payment. It is idempotent on the charge id: a payment Telegram re-delivers
+// (or one already recorded and forwarded) is ignored, so it is never forwarded — and credited —
+// twice.
+func (s *Store) Add(ctx context.Context, r Record) error {
+	_, err := s.db.ExecContext(ctx,
+		`INSERT INTO stars_payments (charge_id, order_id, amount, user_id, created_at, forwarded)
+		 VALUES (?, ?, ?, ?, ?, 0)
+		 ON CONFLICT(charge_id) DO NOTHING`,
+		r.ChargeID, r.OrderID, r.Amount, r.UserID, time.Now().Unix())
+	if err != nil {
+		return fmt.Errorf("outbox: add %s: %w", r.ChargeID, err)
+	}
+	return nil
+}
+
+// Pending returns up to limit payments not yet forwarded, oldest first.
+func (s *Store) Pending(ctx context.Context, limit int) ([]Record, error) {
+	rows, err := s.db.QueryContext(ctx,
+		`SELECT charge_id, order_id, amount, user_id FROM stars_payments
+		 WHERE forwarded = 0 ORDER BY created_at LIMIT ?`, limit)
+	if err != nil {
+		return nil, fmt.Errorf("outbox: read pending: %w", err)
+	}
+	defer rows.Close()
+	var out []Record
+	for rows.Next() {
+		var r Record
+		if err := rows.Scan(&r.ChargeID, &r.OrderID, &r.Amount, &r.UserID); err != nil {
+			return nil, fmt.Errorf("outbox: scan: %w", err)
+		}
+		out = append(out, r)
+	}
+	return out, rows.Err()
+}
+
+// MarkForwarded flags a payment as delivered so it is not forwarded again.
+func (s *Store) MarkForwarded(ctx context.Context, chargeID string) error {
+	if _, err := s.db.ExecContext(ctx,
+		`UPDATE stars_payments SET forwarded = 1 WHERE charge_id = ?`, chargeID); err != nil {
+		return fmt.Errorf("outbox: mark forwarded %s: %w", chargeID, err)
+	}
+	return nil
+}

platform/telegram/internal/outbox/store_test.go

@@ -0,0 +1,124 @@
+package outbox
+
+import (
+	"context"
+	"path/filepath"
+	"testing"
+)
+
+// openTemp opens a fresh outbox in a temp dir.
+func openTemp(t *testing.T) *Store {
+	t.Helper()
+	s, err := Open(filepath.Join(t.TempDir(), "stars.db"))
+	if err != nil {
+		t.Fatalf("open: %v", err)
+	}
+	t.Cleanup(func() { _ = s.Close() })
+	return s
+}
+
+func TestOutboxAddPendingMark(t *testing.T) {
+	ctx := context.Background()
+	s := openTemp(t)
+
+	rec := Record{ChargeID: "ch1", OrderID: "ord1", Amount: 40, UserID: 777}
+	if err := s.Add(ctx, rec); err != nil {
+		t.Fatalf("add: %v", err)
+	}
+	pending, err := s.Pending(ctx, 10)
+	if err != nil {
+		t.Fatalf("pending: %v", err)
+	}
+	if len(pending) != 1 || pending[0] != rec {
+		t.Fatalf("pending = %+v, want [%+v]", pending, rec)
+	}
+
+	if err := s.MarkForwarded(ctx, "ch1"); err != nil {
+		t.Fatalf("mark: %v", err)
+	}
+	pending, err = s.Pending(ctx, 10)
+	if err != nil {
+		t.Fatalf("pending after mark: %v", err)
+	}
+	if len(pending) != 0 {
+		t.Fatalf("pending after mark = %+v, want empty", pending)
+	}
+}
+
+func TestOutboxAddIdempotent(t *testing.T) {
+	ctx := context.Background()
+	s := openTemp(t)
+
+	rec := Record{ChargeID: "dup", OrderID: "ord1", Amount: 80, UserID: 1}
+	if err := s.Add(ctx, rec); err != nil {
+		t.Fatalf("add 1: %v", err)
+	}
+	// A re-delivered payment (same charge id) must not add a second row, even with different fields.
+	if err := s.Add(ctx, Record{ChargeID: "dup", OrderID: "other", Amount: 999, UserID: 2}); err != nil {
+		t.Fatalf("add 2: %v", err)
+	}
+	pending, err := s.Pending(ctx, 10)
+	if err != nil {
+		t.Fatalf("pending: %v", err)
+	}
+	if len(pending) != 1 || pending[0] != rec {
+		t.Fatalf("pending = %+v, want the single original row", pending)
+	}
+}
+
+func TestOutboxAddIgnoresForwarded(t *testing.T) {
+	ctx := context.Background()
+	s := openTemp(t)
+
+	rec := Record{ChargeID: "ch", OrderID: "o", Amount: 40, UserID: 5}
+	if err := s.Add(ctx, rec); err != nil {
+		t.Fatalf("add: %v", err)
+	}
+	if err := s.MarkForwarded(ctx, "ch"); err != nil {
+		t.Fatalf("mark: %v", err)
+	}
+	// A re-delivery after forwarding must not resurrect the row as pending (no double credit).
+	if err := s.Add(ctx, rec); err != nil {
+		t.Fatalf("re-add: %v", err)
+	}
+	pending, err := s.Pending(ctx, 10)
+	if err != nil {
+		t.Fatalf("pending: %v", err)
+	}
+	if len(pending) != 0 {
+		t.Fatalf("pending = %+v, want empty (already forwarded)", pending)
+	}
+}
+
+// TestOutboxReopenReDrives proves a restart re-drives undelivered payments: a payment persisted but
+// not marked forwarded is still pending after the store is reopened from the same file.
+func TestOutboxReopenReDrives(t *testing.T) {
+	ctx := context.Background()
+	dir := t.TempDir()
+	path := filepath.Join(dir, "stars.db")
+
+	s, err := Open(path)
+	if err != nil {
+		t.Fatalf("open: %v", err)
+	}
+	rec := Record{ChargeID: "persist", OrderID: "o1", Amount: 40, UserID: 9}
+	if err := s.Add(ctx, rec); err != nil {
+		t.Fatalf("add: %v", err)
+	}
+	if err := s.Close(); err != nil {
+		t.Fatalf("close: %v", err)
+	}
+
+	reopened, err := Open(path)
+	if err != nil {
+		t.Fatalf("reopen: %v", err)
+	}
+	defer func() { _ = reopened.Close() }()
+	pending, err := reopened.Pending(ctx, 10)
+	if err != nil {
+		t.Fatalf("pending: %v", err)
+	}
+	if len(pending) != 1 || pending[0] != rec {
+		t.Fatalf("pending after reopen = %+v, want the undelivered payment", pending)
+	}
+}

ui/e2e/landing.spec.ts

@@ -58,3 +58,14 @@ test('the landing shows a web-version entry linking /app/, with a caption', asyn
   expect(await web.getAttribute('href')).toContain('/app/');
   await expect(page.getByText('Веб-версия')).toBeVisible();
 });
+
+// The footer carries a public-offer link to the static /offer/ page (rendered from
+// ui/legal/offer_ru.md at build; the legal document a purchase accepts).
+test('the landing footer links to the public offer at /offer/', async ({ page }) => {
+  await page.goto('/landing.html');
+  await expect(page.getByText(/Играй в «Эрудита»/)).toBeVisible(); // Russian by default
+
+  const offer = page.getByRole('link', { name: 'Публичная оферта' });
+  await expect(offer).toBeVisible();
+  expect(await offer.getAttribute('href')).toBe('/offer/');
+});

ui/e2e/wallet.spec.ts

@@ -37,8 +37,27 @@ test('wallet: balances, benefits and the storefront render for a durable account
   await expect(page.getByTestId('product')).toHaveCount(3);
   const pack = page.locator('[data-kind="pack"]');
   await expect(pack).toContainText('₽');
-  // The pack purchase (money intake) is not wired yet, so its action is the disabled 'Soon'.
+  // The pack purchase is wired to money intake: an enabled Buy action, with the public-offer link.
-  await expect(pack.getByRole('button', { name: 'Soon' })).toBeDisabled();
+  await expect(pack.getByTestId('buy-pack')).toBeEnabled();
+  await expect(page.getByTestId('offer')).toContainText('Public offer');
+});
+
+test('wallet: buying a chip pack opens the provider payment page', async ({ page }) => {
+  await loginLobby(page);
+  await openWallet(page);
+
+  // The purchase opens the provider's hosted-payment page in a new tab (window.open); capture it.
+  await page.evaluate(() => {
+    (window as { __opened?: string }).__opened = '';
+    window.open = ((u: string) => {
+      (window as { __opened?: string }).__opened = u;
+      return null;
+    }) as typeof window.open;
+  });
+  await page.locator('[data-kind="pack"]').getByTestId('buy-pack').click();
+  await expect
+    .poll(() => page.evaluate(() => (window as { __opened?: string }).__opened))
+    .toContain('robokassa');
 });
 
 test('wallet: the tab sits between Friends and About', async ({ page }) => {

ui/legal/offer_ru.md

@@ -0,0 +1,145 @@
+# Публичная оферта
+
+Публичная оферта о заключении договора купли-продажи.
+
+## 1. Общие положения
+
+В настоящей Публичной оферте содержатся условия заключения Договора купли-продажи (далее по тексту — «Договор купли-продажи» и/или «Договор»). Настоящей офертой признается предложение, адресованное одному или нескольким конкретным лицам, которое достаточно определенно и выражает намерение лица, сделавшего предложение, считать себя заключившим Договор с адресатом, которым будет принято предложение.
+
+Совершение указанных в настоящей Оферте действий является подтверждением согласия обеих Сторон заключить Договор купли-продажи на условиях, в порядке и объеме, изложенных в настоящей Оферте.
+
+Нижеизложенный текст Публичной оферты является официальным публичным предложением Продавца, адресованный заинтересованному кругу лиц заключить Договор купли-продажи в соответствии с положениями пункта 2 статьи 437 Гражданского кодекса РФ.
+
+Договор купли-продажи считается заключенным и приобретает силу с момента совершения Сторонами действий, предусмотренных в настоящей Оферте, и, означающих безоговорочное, а также полное принятие всех условий настоящей Оферты без каких-либо изъятий или ограничений на условиях присоединения.
+
+### Термины и определения
+
+**Договор** — текст настоящей Оферты с Приложениями, являющимися неотъемлемой частью настоящей Оферты, акцептованный Покупателем путем совершения конклюдентных действий, предусмотренных настоящей Офертой.
+
+**Конклюдентные действия** — это поведение, которое выражает согласие с предложением контрагента заключить, изменить или расторгнуть договор. Действия состоят в полном или частичном выполнении условий, которые предложил контрагент.
+
+**Сайт Продавца в сети «Интернет»** — совокупность программ для электронных вычислительных машин и иной информации, содержащейся в информационной системе, доступ к которой обеспечивается посредством сети «Интернет» по доменному имени и сетевому адресу: `erudit-game.ru`.
+
+**Стороны Договора (Стороны)** — Продавец и Покупатель.
+
+**Товар** — товаром по договору купли-продажи могут быть любые вещи с соблюдением правил, предусмотренных статьей 129 Гражданского кодекса РФ.
+
+## 2. Предмет Договора
+
+**2.1.** По настоящему Договору Продавец обязуется передать вещь (Товар) в собственность Покупателя, а Покупатель обязуется принять Товар и уплатить за него определенную денежную сумму.
+
+**2.2.** Наименование, количество, а также ассортимент Товара, его стоимость, порядок доставки и иные условия определяются на основании сведений Продавца при оформлении заявки Покупателем, либо устанавливаются на сайте Продавца в сети «Интернет» `erudit-game.ru`.
+
+**2.3.** Акцепт настоящей Оферты выражается в совершении конклюдентных действий, в частности:
+
+- действиях, связанных с регистрацией учетной записи на Сайте Продавца в сети «Интернет» при наличии необходимости регистрации учетной записи;
+- путем составления и заполнения заявки на оформление заказа Товара;
+- путем сообщения требуемых для заключения Договора сведений по телефону, электронной почте, указанными на сайте Продавца в сети «Интернет», в том числе, при обратном звонке Продавца по заявке Покупателя;
+- оплаты Товара Покупателем.
+
+Данный перечень не является исчерпывающим, могут быть и другие действия, которые ясно выражают намерение лица принять предложение контрагента.
+
+## 3. Права и обязанности Сторон
+
+### 3.1. Права и обязанности Продавца
+
+**3.1.1.** Продавец вправе требовать оплаты Товаров и их доставки в порядке и на условиях, предусмотренных Договором;
+
+**3.1.2.** Отказать в заключении Договора на основании настоящей Оферты Покупателю в случае его недобросовестного поведения, в частности, в случае:
+
+- более 2 (Двух) отказов от Товаров надлежащего качества в течение года;
+- предоставления заведомо недостоверной персональной информации;
+- возврата испорченного Покупателем Товара или Товара, бывшего в употреблении;
+- иных случаях недобросовестного поведения, свидетельствующих о заключении Покупателем Договора с целью злоупотребления правами, и отсутствия обычной экономической цели Договора — приобретения Товара.
+
+**3.1.3.** Продавец обязуется передать Покупателю Товар надлежащего качества и в надлежащей упаковке;
+
+**3.1.4.** Передать Товар свободным от прав третьих лиц;
+
+**3.1.5.** Организовать доставку Товаров Покупателю;
+
+**3.1.6.** Предоставить Покупателю всю необходимую информацию в соответствии с требованиями действующего законодательства РФ и настоящей Оферты;
+
+### 3.2. Права и обязанности Покупателя
+
+**3.2.1.** Покупатель вправе требовать передачи Товара в порядке и на условиях, предусмотренных Договором.
+
+**3.2.2.** Требовать предоставления всей необходимой информации в соответствии с требованиями действующего законодательства РФ и настоящей Оферты;
+
+**3.2.3.** Отказаться от Товара по основаниям, предусмотренным Договором и действующим законодательством Российской Федерации.
+
+**3.2.4.** Покупатель обязуется предоставить Продавцу достоверную информацию, необходимую для надлежащего исполнения Договора;
+
+**3.2.5.** Принять и оплатить Товар в соответствии с условиями Договора;
+
+**3.2.6.** Покупатель гарантирует, что все условия Договора ему понятны; Покупатель принимает условия без оговорок, а также в полном объеме.
+
+## 4. Цена и порядок расчетов
+
+**4.1.** Стоимость, а также порядок оплаты Товара определяется на основании сведений Продавца при оформлении заявки Покупателем, либо устанавливаются на сайте Продавца в сети «Интернет»: `erudit-game.ru`.
+
+**4.2.** Все расчеты по Договору производятся в безналичном порядке.
+
+## 5. Обмен и возврат Товара
+
+**5.1.** Покупатель вправе осуществить возврат (обмен) Продавцу Товара, приобретенный дистанционным способом, за исключением перечня товаров, не подлежащих обмену и возврату согласно действующему законодательству Российской Федерации. Условия, сроки и порядок возврата Товара надлежащего и ненадлежащего качества установлены в соответствии с Гражданским кодексом РФ, Закона РФ от 07.02.1992 N 2300-1 «О защите прав потребителей», Правил, утвержденных Постановлением Правительства РФ от 31.12.2020 N 2463.
+
+**5.2.** Требование Покупателя об обмене либо о возврате Товара рассматривается индивидуально при условии неиспользования приобретенного товара и наличии уважительных причин (технический сбой, ошибка в описании товара).
+
+## 6. Конфиденциальность и безопасность
+
+**6.1.** При реализации настоящего Договора Стороны обеспечивают конфиденциальность и безопасность персональных данных в соответствии с актуальной редакцией ФЗ от 27.07.2006 г. № 152-ФЗ «О персональных данных» и ФЗ от 27.07.2006 г. № 149-ФЗ «Об информации, информационных технологиях и о защите информации».
+
+**6.2.** Стороны обязуются сохранять конфиденциальность информации, полученной в ходе исполнения настоящего Договора, и принять все возможные меры, чтобы предохранить полученную информацию от разглашения.
+
+**6.3.** Под конфиденциальной информацией понимается любая информация, передаваемая Продавцом и Покупателем в процессе реализации Договора и подлежащая защите, исключения указаны ниже.
+
+**6.4.** Такая информация может содержаться в предоставляемых Продавцом локальных нормативных актах, договорах, письмах, отчетах, аналитических материалах, результатах исследований, схемах, графиках, спецификациях и других документах, оформленных как на бумажных, так и на электронных носителях.
+
+## 7. Форс-мажор
+
+**7.1.** Стороны освобождаются от ответственности за неисполнение или ненадлежащее исполнение обязательств по Договору, если надлежащее исполнение оказалось невозможным вследствие непреодолимой силы, то есть чрезвычайных и непредотвратимых при данных условиях обстоятельств, под которыми понимаются: запретные действия властей, эпидемии, блокада, эмбарго, землетрясения, наводнения, пожары или другие стихийные бедствия.
+
+**7.2.** В случае наступления этих обстоятельств Сторона обязана в течение 30 (Тридцати) рабочих дней уведомить об этом другую Сторону.
+
+**7.3.** Документ, выданный уполномоченным государственным органом, является достаточным подтверждением наличия и продолжительности действия непреодолимой силы.
+
+**7.4.** Если обстоятельства непреодолимой силы продолжают действовать более 60 (Шестидесяти) рабочих дней, то каждая Сторона вправе отказаться от настоящего Договора в одностороннем порядке.
+
+## 8. Ответственность Сторон
+
+**8.1.** В случае неисполнения и/или ненадлежащего исполнения своих обязательств по Договору, Стороны несут ответственность в соответствии с условиями настоящей Оферты.
+
+**8.2.** Сторона, не исполнившая или ненадлежащим образом исполнившая обязательства по Договору, обязана возместить другой Стороне причиненные такими нарушениями убытки.
+
+## 9. Срок действия настоящей Оферты
+
+**9.1.** Оферта вступает в силу с момента размещения на Сайте Продавца и действует до момента её отзыва Продавцом.
+
+**9.2.** Продавец оставляет за собой право внести изменения в условия Оферты и/или отозвать Оферту в любой момент по своему усмотрению. Сведения об изменении или отзыве Оферты доводятся до Покупателя по выбору Продавца посредством размещения на сайте Продавца в сети «Интернет», в Личном кабинете Покупателя, либо путем направления соответствующего уведомления на электронный или почтовый адрес, указанный Покупателем при заключении Договора или в ходе его исполнения.
+
+**9.3.** Договор вступает в силу с момента Акцепта условий настоящей Оферты Покупателем и действует до полного исполнения Сторонами обязательств по Договору.
+
+**9.4.** Изменения, внесенные Продавцом в Договор и опубликованные на сайте в форме актуализированной Оферты, считаются принятыми Покупателем в полном объеме.
+
+## 10. Дополнительные условия
+
+**10.1.** Договор, его заключение и исполнение регулируется действующим законодательством Российской Федерации. Все вопросы, не урегулированные настоящей Офертой или урегулированные не полностью, регулируются в соответствии с материальным правом Российской Федерации.
+
+**10.2.** В случае возникновения спора, который может возникнуть между Сторонами в ходе исполнения ими своих обязательств по Договору, заключенному на условиях настоящей Оферты, Стороны обязаны урегулировать спор мирным путем до начала судебного разбирательства.
+
+Судебное разбирательство осуществляется в соответствии с законодательством Российской Федерации.
+
+Споры или разногласия, по которым Стороны не достигли договоренности, подлежат разрешению в соответствии с законодательством РФ. Досудебный порядок урегулирования спора является обязательным.
+
+**10.3.** В качестве языка Договора, заключаемого на условиях настоящей Оферты, а также языка, используемого при любом взаимодействии Сторон (включая ведение переписки, предоставление требований / уведомлений / разъяснений, предоставление документов и т. д.), Стороны определили русский язык.
+
+**10.4.** Все документы, подлежащие предоставлению в соответствии с условиями настоящей Оферты, должны быть составлены на русском языке либо иметь перевод на русский язык, удостоверенный в установленном порядке.
+
+**10.5.** Бездействие одной из Сторон в случае нарушения условий настоящей Оферты не лишает права заинтересованной Стороны осуществлять защиту своих интересов позднее, а также не означает отказа от своих прав в случае совершения одной из Сторон подобных либо сходных нарушений в будущем.
+
+**10.6.** Если на Сайте Продавца в сети «Интернет» есть ссылки на другие веб-сайты и материалы третьих лиц, такие ссылки размещены исключительно в целях информирования, и Продавец не имеет контроля в отношении содержания таких сайтов или материалов. Продавец не несет ответственность за любые убытки или ущерб, которые могут возникнуть в результате использования таких ссылок.
+
+## 11. Реквизиты Продавца
+
+Денисов Илья Аркадьевич, ИНН 290210610742.

ui/package.json

@@ -28,6 +28,7 @@
     "@sveltejs/vite-plugin-svelte": "^5.0.0",
     "@types/node": "^22.10.0",
     "core-js-bundle": "^3.49.0",
+    "marked": "^18.0.5",
     "svelte": "^5.15.0",
     "svelte-check": "^4.1.0",
     "typescript": "^5.7.0",

ui/pnpm-lock.yaml

@@ -39,6 +39,9 @@ importers:
       core-js-bundle:
         specifier: ^3.49.0
         version: 3.49.0
+      marked:
+        specifier: ^18.0.5
+        version: 18.0.5
       svelte:
         specifier: ^5.15.0
         version: 5.56.0
@@ -1628,6 +1631,11 @@ packages:
   magic-string@0.30.21:
     resolution: {integrity: sha512-vd2F4YUyEXKGcLHoq+TEyCjxueSeHnFxyyjNp80yg0XV4vUhnDer/lvvlqM/arB5bXQN5K2/3oinyCRyx8T2CQ==}
 
+  marked@18.0.5:
+    resolution: {integrity: sha512-S6GcvALHg6K4ohtu4E7x0a1AqhAjp6cV8KhLSyN9qVapnzJkusVBxZRcIU9AeYsbe6P1hKDusSbEOzGyyuce6w==}
+    engines: {node: '>= 20'}
+    hasBin: true
+
   math-intrinsics@1.1.0:
     resolution: {integrity: sha512-/IXtbwEk5HTPyEwyKX6hGkYXxM9nbj64B+ilVJnC/R6B0pH5G4V3b0pVbL7DBj4tkhBAppbQUlf6F6Xl9LHu1g==}
     engines: {node: '>= 0.4'}
@@ -3877,6 +3885,8 @@ snapshots:
     dependencies:
       '@jridgewell/sourcemap-codec': 1.5.5
 
+  marked@18.0.5: {}
+
   math-intrinsics@1.1.0: {}
 
   minimatch@10.2.5:

ui/scripts/bundle-size.mjs

@@ -28,9 +28,11 @@ const DIST = 'dist';
 // live in the always-loaded New Game / Game / Lobby screens (the offline engine and the tiny PIN
 // hashing stay in lazy chunks / are negligible), then to 123 for the Wallet section — its screen,
 // storefront logic and the catalog codec load with the always-mounted settings hub (its i18n lands
-// in the shared chunk). The heavy parts — the dict loader, the move generator and the preload
+// in the shared chunk) — and to 125 for the payment intake rails: the wallet order flow, the
+// Telegram Stars openInvoice / VK order-box launch and the per-button in-flight state ride the same
+// always-loaded Wallet screen. The heavy parts — the dict loader, the move generator and the preload
 // orchestration — still stay in lazy chunks. Scoped CSS lands in the CSS chunk, not this JS budget.
-const BUDGET = { app: 123, shared: 30, landing: 5 };
+const BUDGET = { app: 125, shared: 30, landing: 5 };
 
 // gzipped returns the gzipped byte size of a built asset, or 0 when the reference is not a
 // local file (e.g. the Telegram SDK loaded from a CDN) or is missing.

ui/src/Landing.svelte

@@ -123,7 +123,10 @@
     </div>
   </section>
 
-  <footer class="ft">{t('about.version', { v: __APP_VERSION__ })}</footer>
+  <footer class="ft">
+    <a class="offer" href="/offer/">{t('landing.offer')}</a>
+    <span>{t('about.version', { v: __APP_VERSION__ })}</span>
+  </footer>
 </main>
 
 <style>
@@ -275,8 +278,18 @@
   }
   .ft {
     margin-top: auto;
+    display: flex;
+    flex-direction: column;
+    align-items: center;
+    gap: 6px;
     text-align: center;
     color: var(--text-muted);
     font-size: 0.8rem;
   }
+  .ft .offer {
+    color: inherit;
+  }
+  .ft .offer:hover {
+    color: var(--accent);
+  }
 </style>

ui/src/gen/fbs/scrabblefb.ts

@@ -86,6 +86,8 @@ export { UpdateProfileRequest } from './scrabblefb/update-profile-request.js';
 export { VKLoginRequest } from './scrabblefb/vklogin-request.js';
 export { Wallet } from './scrabblefb/wallet.js';
 export { WalletBuyRequest } from './scrabblefb/wallet-buy-request.js';
+export { WalletOrderRequest } from './scrabblefb/wallet-order-request.js';
+export { WalletOrderResponse } from './scrabblefb/wallet-order-response.js';
 export { WalletSegment } from './scrabblefb/wallet-segment.js';
 export { WordCheckResult } from './scrabblefb/word-check-result.js';
 export { YourTurnEvent } from './scrabblefb/your-turn-event.js';

ui/src/gen/fbs/scrabblefb/wallet-order-request.ts

@@ -0,0 +1,48 @@
+// automatically generated by the FlatBuffers compiler, do not modify
+
+import * as flatbuffers from 'flatbuffers';
+
+export class WalletOrderRequest {
+  bb: flatbuffers.ByteBuffer|null = null;
+  bb_pos = 0;
+  __init(i:number, bb:flatbuffers.ByteBuffer):WalletOrderRequest {
+  this.bb_pos = i;
+  this.bb = bb;
+  return this;
+}
+
+static getRootAsWalletOrderRequest(bb:flatbuffers.ByteBuffer, obj?:WalletOrderRequest):WalletOrderRequest {
+  return (obj || new WalletOrderRequest()).__init(bb.readInt32(bb.position()) + bb.position(), bb);
+}
+
+static getSizePrefixedRootAsWalletOrderRequest(bb:flatbuffers.ByteBuffer, obj?:WalletOrderRequest):WalletOrderRequest {
+  bb.setPosition(bb.position() + flatbuffers.SIZE_PREFIX_LENGTH);
+  return (obj || new WalletOrderRequest()).__init(bb.readInt32(bb.position()) + bb.position(), bb);
+}
+
+productId():string|null
+productId(optionalEncoding:flatbuffers.Encoding):string|Uint8Array|null
+productId(optionalEncoding?:any):string|Uint8Array|null {
+  const offset = this.bb!.__offset(this.bb_pos, 4);
+  return offset ? this.bb!.__string(this.bb_pos + offset, optionalEncoding) : null;
+}
+
+static startWalletOrderRequest(builder:flatbuffers.Builder) {
+  builder.startObject(1);
+}
+
+static addProductId(builder:flatbuffers.Builder, productIdOffset:flatbuffers.Offset) {
+  builder.addFieldOffset(0, productIdOffset, 0);
+}
+
+static endWalletOrderRequest(builder:flatbuffers.Builder):flatbuffers.Offset {
+  const offset = builder.endObject();
+  return offset;
+}
+
+static createWalletOrderRequest(builder:flatbuffers.Builder, productIdOffset:flatbuffers.Offset):flatbuffers.Offset {
+  WalletOrderRequest.startWalletOrderRequest(builder);
+  WalletOrderRequest.addProductId(builder, productIdOffset);
+  return WalletOrderRequest.endWalletOrderRequest(builder);
+}
+}

ui/src/gen/fbs/scrabblefb/wallet-order-response.ts

@@ -0,0 +1,60 @@
+// automatically generated by the FlatBuffers compiler, do not modify
+
+import * as flatbuffers from 'flatbuffers';
+
+export class WalletOrderResponse {
+  bb: flatbuffers.ByteBuffer|null = null;
+  bb_pos = 0;
+  __init(i:number, bb:flatbuffers.ByteBuffer):WalletOrderResponse {
+  this.bb_pos = i;
+  this.bb = bb;
+  return this;
+}
+
+static getRootAsWalletOrderResponse(bb:flatbuffers.ByteBuffer, obj?:WalletOrderResponse):WalletOrderResponse {
+  return (obj || new WalletOrderResponse()).__init(bb.readInt32(bb.position()) + bb.position(), bb);
+}
+
+static getSizePrefixedRootAsWalletOrderResponse(bb:flatbuffers.ByteBuffer, obj?:WalletOrderResponse):WalletOrderResponse {
+  bb.setPosition(bb.position() + flatbuffers.SIZE_PREFIX_LENGTH);
+  return (obj || new WalletOrderResponse()).__init(bb.readInt32(bb.position()) + bb.position(), bb);
+}
+
+orderId():string|null
+orderId(optionalEncoding:flatbuffers.Encoding):string|Uint8Array|null
+orderId(optionalEncoding?:any):string|Uint8Array|null {
+  const offset = this.bb!.__offset(this.bb_pos, 4);
+  return offset ? this.bb!.__string(this.bb_pos + offset, optionalEncoding) : null;
+}
+
+redirectUrl():string|null
+redirectUrl(optionalEncoding:flatbuffers.Encoding):string|Uint8Array|null
+redirectUrl(optionalEncoding?:any):string|Uint8Array|null {
+  const offset = this.bb!.__offset(this.bb_pos, 6);
+  return offset ? this.bb!.__string(this.bb_pos + offset, optionalEncoding) : null;
+}
+
+static startWalletOrderResponse(builder:flatbuffers.Builder) {
+  builder.startObject(2);
+}
+
+static addOrderId(builder:flatbuffers.Builder, orderIdOffset:flatbuffers.Offset) {
+  builder.addFieldOffset(0, orderIdOffset, 0);
+}
+
+static addRedirectUrl(builder:flatbuffers.Builder, redirectUrlOffset:flatbuffers.Offset) {
+  builder.addFieldOffset(1, redirectUrlOffset, 0);
+}
+
+static endWalletOrderResponse(builder:flatbuffers.Builder):flatbuffers.Offset {
+  const offset = builder.endObject();
+  return offset;
+}
+
+static createWalletOrderResponse(builder:flatbuffers.Builder, orderIdOffset:flatbuffers.Offset, redirectUrlOffset:flatbuffers.Offset):flatbuffers.Offset {
+  WalletOrderResponse.startWalletOrderResponse(builder);
+  WalletOrderResponse.addOrderId(builder, orderIdOffset);
+  WalletOrderResponse.addRedirectUrl(builder, redirectUrlOffset);
+  return WalletOrderResponse.endWalletOrderResponse(builder);
+}
+}

ui/src/lib/app.svelte.ts

@@ -137,6 +137,9 @@ export const app = $state<{
   /** Whether an operator feedback reply awaits the player, for the lobby ⚙️ badge (combined
    *  with friend requests) and the Settings → Info badge. */
   feedbackReplyUnread: boolean;
+  /** A monotone counter bumped when a payment-intake push signals the wallet changed; an open
+   *  Wallet screen watches it and re-fetches in place. */
+  walletRefresh: number;
   /** Whether to show the "outdated invite link" notice: set when a Telegram deep-link friend
    *  code is already used/expired, so the visitor lands in the lobby with a gentle pointer to
    *  the bot instead of a scary error on the Friends screen. */
@@ -175,6 +178,7 @@ export const app = $state<{
   chatUnread: {},
   messageUnread: {},
   feedbackReplyUnread: false,
+  walletRefresh: 0,
   staleInvite: false,
   welcomeRedeem: false,
   resync: 0,
@@ -439,6 +443,12 @@ function openStream(): void {
         if (e.sub === 'profile') {
           void refreshProfile();
         }
+        // A payment-intake event credited (or refunded) the viewer's wallet: bump the signal an
+        // open Wallet screen watches, so it re-fetches in place (the return-focus poll is the
+        // fallback when the live stream is down).
+        if (e.sub === 'payment') {
+          app.walletRefresh++;
+        }
         void refreshNotifications();
       }
     },

ui/src/lib/client.ts

@@ -35,6 +35,7 @@ import type {
   Variant,
   WordCheckResult,
   Wallet,
+  WalletOrder,
   Catalog,
 } from './model';
 
@@ -147,6 +148,9 @@ export interface GatewayClient {
   /** walletBuy spends chips on a chip-priced value and returns the updated wallet. Gate-checked
    *  server-side: an untrusted/frozen context or an insufficient balance is refused. */
   walletBuy(productId: string): Promise<Wallet>;
+  /** walletOrder opens a money order to fund a chip pack and returns the provider launch URL the
+   *  client opens; chips are credited later, by the verified server callback. Direct rail only. */
+  walletOrder(productId: string): Promise<WalletOrder>;
 
   // --- friends ---
   friendsList(): Promise<AccountRef[]>;

ui/src/lib/codec.test.ts

@@ -17,6 +17,8 @@ import {
   decodeWallet,
   decodeCatalog,
   encodeWalletBuy,
+  encodeWalletOrder,
+  decodeWalletOrder,
   decodeSession,
   decodeFeedbackState,
   decodeFeedbackUnread,
@@ -73,6 +75,25 @@ describe('codec', () => {
     expect(w.hints).toBe(5);
   });
 
+  it('round-trips the wallet order request and response', () => {
+    // order request: pack id survives the wire
+    const req = fb.WalletOrderRequest.getRootAsWalletOrderRequest(new ByteBuffer(encodeWalletOrder('pack-7')));
+    expect(req.productId()).toBe('pack-7');
+
+    // order response: the created id and the provider launch URL decode back
+    const b = new Builder(64);
+    const oid = b.createString('order-123');
+    const url = b.createString('https://pay.example/abc');
+    fb.WalletOrderResponse.startWalletOrderResponse(b);
+    fb.WalletOrderResponse.addOrderId(b, oid);
+    fb.WalletOrderResponse.addRedirectUrl(b, url);
+    b.finish(fb.WalletOrderResponse.endWalletOrderResponse(b));
+
+    const order = decodeWalletOrder(b.asUint8Array());
+    expect(order.orderId).toBe('order-123');
+    expect(order.redirectUrl).toBe('https://pay.example/abc');
+  });
+
   it('round-trips the catalog view (value + pack)', () => {
     const b = new Builder(256);
 

ui/src/lib/codec.ts

@@ -39,6 +39,7 @@ import type {
   MoveResult,
   Profile,
   Wallet,
+  WalletOrder,
   WalletSegment,
   Catalog,
   CatalogProduct,
@@ -373,6 +374,15 @@ export function encodeWalletBuy(productId: string): Uint8Array {
   return finish(b, fb.WalletBuyRequest.endWalletBuyRequest(b));
 }
 
+// encodeWalletOrder wraps the pack id for a money order (POST /user/wallet/order).
+export function encodeWalletOrder(productId: string): Uint8Array {
+  const b = new Builder(64);
+  const pid = b.createString(productId);
+  fb.WalletOrderRequest.startWalletOrderRequest(b);
+  fb.WalletOrderRequest.addProductId(b, pid);
+  return finish(b, fb.WalletOrderRequest.endWalletOrderRequest(b));
+}
+
 // decodeWallet reads the wallet payload: the context-visible chip segments and the
 // context-applicable benefits.
 export function decodeWallet(buf: Uint8Array): Wallet {
@@ -391,6 +401,12 @@ export function decodeWallet(buf: Uint8Array): Wallet {
   };
 }
 
+// decodeWalletOrder reads the created order: its id and the provider launch URL the client opens.
+export function decodeWalletOrder(buf: Uint8Array): WalletOrder {
+  const o = fb.WalletOrderResponse.getRootAsWalletOrderResponse(new ByteBuffer(buf));
+  return { orderId: s(o.orderId()), redirectUrl: s(o.redirectUrl()) };
+}
+
 // decodeCatalog reads the storefront payload: the context-visible products, each a chip-priced
 // value or a chip pack priced in the context's payment method, with its atom composition.
 export function decodeCatalog(buf: Uint8Array): Catalog {

ui/src/lib/i18n/en.ts

@@ -242,7 +242,11 @@ export const en = {
   'wallet.store': 'Store',
   'wallet.empty': 'The store is empty for now',
   'wallet.buy': 'Buy',
-  'wallet.soon': 'Soon',
+  'wallet.offer': 'Public offer',
+  'wallet.platformNoBuy': 'Purchases are not available on this platform',
+  'wallet.iosBlockedPre': 'Purchases on iOS are prohibited by Apple policy. Try the ',
+  'wallet.iosBlockedLink': 'other version',
+  'wallet.iosBlockedPost': ' of the game.',
   'wallet.gpStub': 'To buy chips, install the RuStore build.',
   'wallet.cur.RUB': '₽',
   'wallet.cur.VOTE': 'votes',
@@ -275,6 +279,7 @@ export const en = {
   'landing.captionTelegram': 'Telegram',
   'landing.captionVK': 'VK',
   'landing.captionWeb': 'Web',
+  'landing.offer': 'Public offer',
 
   'install.title': 'Install the app',
   'install.subtitle': 'Put the app icon on your desktop (home screen) to open the game in one tap.',

ui/src/lib/i18n/ru.ts

@@ -242,7 +242,11 @@ export const ru: Record<MessageKey, string> = {
   'wallet.store': 'Магазин',
   'wallet.empty': 'Магазин пока пуст',
   'wallet.buy': 'Купить',
-  'wallet.soon': 'Скоро',
+  'wallet.offer': 'Публичная оферта',
+  'wallet.platformNoBuy': 'На данной платформе покупки невозможны',
+  'wallet.iosBlockedPre': 'Покупки на iOS запрещены политикой Apple. Попробуйте воспользоваться ',
+  'wallet.iosBlockedLink': 'другой версией',
+  'wallet.iosBlockedPost': ' игры.',
   'wallet.gpStub': 'Чтобы покупать фишки, установите версию из RuStore.',
   'wallet.cur.RUB': '₽',
   'wallet.cur.VOTE': 'голосов',
@@ -275,6 +279,7 @@ export const ru: Record<MessageKey, string> = {
   'landing.captionTelegram': 'Telegram',
   'landing.captionVK': 'VK',
   'landing.captionWeb': 'Веб-версия',
+  'landing.offer': 'Публичная оферта',
 
   'install.title': 'Установить приложение',
   'install.subtitle': 'Поместите иконку приложения на рабочий стол (домашний экран), чтобы открывать игру одним нажатием.',

ui/src/lib/mock/client.ts

@@ -41,6 +41,7 @@ import type {
   Variant,
   WordCheckResult,
   Wallet,
+  WalletOrder,
   Catalog,
 } from '../model';
 import { valueForLetter } from '../alphabet';
@@ -225,6 +226,14 @@ export class MockGateway implements GatewayClient {
     }
     return this.cloneWallet();
   }
+
+  async walletOrder(productId: string): Promise<WalletOrder> {
+    const p = this.mockCatalog.products.find((x) => x.productId === productId);
+    if (!p || p.kind !== 'pack') throw new GatewayError('not_a_pack');
+    // No real provider in mock: return a stub launch URL so the e2e can assert the purchase reaches
+    // the provider hand-off without leaving the app.
+    return { orderId: 'mock-order-' + productId, redirectUrl: 'https://mock.local/robokassa?order=' + productId };
+  }
   private cloneWallet(): Wallet {
     return {
       segments: this.mockWallet.segments.map((s) => ({ ...s })),

ui/src/lib/model.ts

@@ -172,6 +172,14 @@ export interface Wallet {
 
 /** One atom line of a storefront product: the base value type it grants ("chips"/"hints"/
  *  "noads_days"/"tournament") and how many of it the product carries. */
+// WalletOrder is a created money order to fund a chip pack: its id and the provider launch URL the
+// client opens (the Robokassa hosted-payment page). Chips arrive later, by the verified server
+// callback.
+export interface WalletOrder {
+  orderId: string;
+  redirectUrl: string;
+}
+
 export interface CatalogAtom {
   atomType: string;
   quantity: number;

ui/src/lib/offer.test.ts

@@ -0,0 +1,23 @@
+import { describe, it, expect } from 'vitest';
+import { renderOfferHtml } from './offer';
+
+describe('renderOfferHtml', () => {
+  it('wraps rendered markdown in a standalone Russian HTML document', () => {
+    const html = renderOfferHtml('# Публичная оферта\n\nо заключении договора купли-продажи');
+    expect(html).toContain('<!doctype html>');
+    expect(html).toContain('lang="ru"');
+    expect(html).toContain('<title>Публичная оферта — Эрудит</title>');
+    // The markdown heading is rendered, not left as literal source.
+    expect(html).toContain('<h1>Публичная оферта</h1>');
+    expect(html).not.toContain('# Публичная оферта');
+    // A back link to the landing root is always present.
+    expect(html).toContain('href="/"');
+  });
+
+  it('renders headings, bold clause numbers and lists', () => {
+    const html = renderOfferHtml('## 2. Предмет\n\n**2.1.** Текст пункта.\n\n- первый\n- второй');
+    expect(html).toContain('<h2>2. Предмет</h2>');
+    expect(html).toContain('<strong>2.1.</strong>');
+    expect(html).toContain('<li>первый</li>');
+  });
+});

ui/src/lib/offer.ts

@@ -0,0 +1,93 @@
+import { marked } from 'marked';
+
+/**
+ * renderOfferHtml renders the public-offer markdown source into a standalone,
+ * self-contained HTML document served statically at `/offer/`. The build emits
+ * the result as `dist/offer/index.html` (see the `emit-offer` plugin in
+ * `vite.config.ts`), which the landing container serves.
+ *
+ * The input `markdown` is trusted repository content (the owner-edited
+ * `ui/legal/offer_ru.md`), not user input, so the rendered HTML is deliberately
+ * not sanitised. The page carries its own minimal light/dark styling so it needs
+ * neither the app bundle nor `app.css`.
+ */
+export function renderOfferHtml(markdown: string): string {
+  const body = marked.parse(markdown, { async: false }) as string;
+  return `<!doctype html>
+<html lang="ru">
+  <head>
+    <meta charset="UTF-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1" />
+    <title>Публичная оферта — Эрудит</title>
+    <link rel="canonical" href="https://erudit-game.ru/offer/" />
+    <meta name="theme-color" media="(prefers-color-scheme: light)" content="#f3f4f6" />
+    <meta name="theme-color" media="(prefers-color-scheme: dark)" content="#0f1115" />
+    <style>
+      :root {
+        color-scheme: light dark;
+        --bg: #ffffff;
+        --text: #1a1c20;
+        --accent: #2563eb;
+        --rule: #e5e7eb;
+      }
+      @media (prefers-color-scheme: dark) {
+        :root {
+          --bg: #0f1115;
+          --text: #e7e9ee;
+          --accent: #6ea8fe;
+          --rule: #242832;
+        }
+      }
+      * {
+        box-sizing: border-box;
+      }
+      body {
+        margin: 0;
+        background: var(--bg);
+        color: var(--text);
+        font: 16px/1.6 system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif;
+      }
+      main {
+        max-width: 760px;
+        margin: 0 auto;
+        padding: 24px 20px 64px;
+      }
+      a {
+        color: var(--accent);
+      }
+      .back {
+        display: inline-block;
+        margin-bottom: 20px;
+        text-decoration: none;
+      }
+      h1 {
+        font-size: 1.6rem;
+        text-align: center;
+      }
+      h2 {
+        font-size: 1.2rem;
+        margin-top: 2em;
+        padding-top: 1em;
+        border-top: 1px solid var(--rule);
+      }
+      h3 {
+        font-size: 1.05rem;
+        margin-top: 1.5em;
+      }
+      ul {
+        padding-left: 1.25em;
+      }
+      li {
+        margin: 0.25em 0;
+      }
+    </style>
+  </head>
+  <body>
+    <main>
+      <a class="back" href="/">← На главную</a>
+      ${body}
+    </main>
+  </body>
+</html>
+`;
+}

ui/src/lib/telegram.ts

@@ -39,6 +39,7 @@ interface TelegramWebApp {
   close?: () => void;
   openTelegramLink?: (url: string) => void;
   openLink?: (url: string) => void;
+  openInvoice?: (url: string, callback?: (status: string) => void) => void;
   onEvent?: (event: string, handler: () => void) => void;
   setHeaderColor?: (color: string) => void;
   setBackgroundColor?: (color: string) => void;
@@ -170,6 +171,20 @@ export function telegramOpenLink(url: string): boolean {
   return true;
 }
 
+/**
+ * telegramOpenInvoice opens a Telegram Stars invoice inside the Mini App (WebApp.openInvoice) and
+ * calls onStatus with the outcome ('paid' | 'cancelled' | 'failed' | 'pending'). Returns false
+ * outside Telegram or when the SDK lacks the method. The invoice url is the createInvoiceLink the
+ * bot minted for the order; the chips are credited server-side by the forwarded payment, so 'paid'
+ * only signals to refresh the wallet — the live push is the authoritative update.
+ */
+export function telegramOpenInvoice(url: string, onStatus?: (status: string) => void): boolean {
+  const w = webApp();
+  if (!w?.openInvoice) return false;
+  w.openInvoice(url, onStatus);
+  return true;
+}
+
 /**
  * telegramOpenExternalLink opens an arbitrary external URL through the Mini App SDK's openLink,
  * so Telegram opens it directly in its in-app browser instead of the WebView's generic "open

ui/src/lib/transport.ts

@@ -237,6 +237,9 @@ export function createTransport(baseUrl: string): GatewayClient {
     async walletBuy(productId: string) {
       return codec.decodeWallet(await exec('wallet.buy', codec.encodeWalletBuy(productId)));
     },
+    async walletOrder(productId: string) {
+      return codec.decodeWalletOrder(await exec('wallet.order', codec.encodeWalletOrder(productId)));
+    },
 
     async friendsList() {
       return codec.decodeFriendList(await exec('friends.list', codec.empty()));

ui/src/lib/vk.ts

@@ -182,6 +182,21 @@ export async function vkShowImages(url: string): Promise<boolean> {
   }
 }
 
+/**
+ * vkShowOrderBox opens VK's payment box for a "голоса" item purchase; item is the order id the
+ * backend created (VK echoes it to our payment callback, which credits). Resolves true when the
+ * payment completes, false on cancel/failure or outside VK. The chips are credited by the server
+ * callback, so the wallet refreshes from the payment push regardless of this result.
+ */
+export async function vkShowOrderBox(item: string): Promise<boolean> {
+  try {
+    await (await bridge()).send('VKWebAppShowOrderBox', { type: 'item', item });
+    return true;
+  } catch {
+    return false;
+  }
+}
+
 /**
  * vkDownloadFile downloads url as filename through the VK client (VKWebAppDownloadFile) —
  * the mobile in-app file delivery, where the webview ignores <a download>. Resolves false

ui/src/screens/Wallet.svelte

@@ -1,11 +1,15 @@
 <script lang="ts">
   import { onMount } from 'svelte';
   import Modal from '../components/Modal.svelte';
-  import { handleError } from '../lib/app.svelte';
+  import { app, handleError, showToast } from '../lib/app.svelte';
   import { gateway } from '../lib/gateway';
+  import { normalizeSubtype } from '../lib/platform';
   import { t, i18n, type MessageKey } from '../lib/i18n/index.svelte';
   import { executionContext, formatAmount, needsWebSpendWarning, type SpendContext } from '../lib/wallet';
   import { isGooglePlayBuild } from '../lib/distribution';
+  import { onExternalLinkClick, openExternalUrl } from '../lib/links';
+  import { vkPlatform, vkShowOrderBox } from '../lib/vk';
+  import { telegramOpenInvoice } from '../lib/telegram';
   import type { Wallet, Catalog, CatalogProduct } from '../lib/model';
 
   // The Wallet section: the context-visible chip balances, the active benefits, and the storefront.
@@ -17,12 +21,22 @@
   let wallet = $state<Wallet | null>(null);
   let catalog = $state<Catalog | null>(null);
   let loading = $state(true);
-  let busy = $state(false);
+  // The product whose purchase is in flight, or null. It both guards against a concurrent purchase
+  // (busy) and scopes the pressed/dimmed visual to the tapped button — not every buy button.
+  let busyId = $state<string | null>(null);
+  const busy = $derived(busyId !== null);
   // The value awaiting a web-spend warning confirmation (a spend that would draw vk/tg chips).
   let warnProduct = $state<CatalogProduct | null>(null);
 
   const context: SpendContext = executionContext();
   const gpBuild = isGooglePlayBuild();
+  // Money purchases are not permitted inside the VK iOS app (Apple ToS); the pack CTA is shown
+  // muted and taps explain why, rather than hiding the storefront. VK's device family is not on the
+  // client platformSubtype (server-derived) — read it from the signed vk_platform launch param.
+  const purchaseBlocked = context === 'vk' && normalizeSubtype(vkPlatform()) === 'ios';
+  // The "other version" link points at this deployment's own site root (the landing lists every
+  // platform), so it follows prod vs the contour without a hardcoded host.
+  const siteRoot = typeof location !== 'undefined' ? `${location.origin}/` : '/';
 
   const values = $derived(catalog?.products.filter((p) => p.kind === 'value') ?? []);
   const packs = $derived(catalog?.products.filter((p) => p.kind === 'pack') ?? []);
@@ -38,7 +52,26 @@
       loading = false;
     }
   }
-  onMount(load);
+  onMount(() => {
+    void load();
+    // Fallback to the payment push: re-fetch when the tab regains focus, i.e. the user returned
+    // from the provider's payment window.
+    const onVisible = () => {
+      if (!document.hidden) void load();
+    };
+    document.addEventListener('visibilitychange', onVisible);
+    return () => document.removeEventListener('visibilitychange', onVisible);
+  });
+
+  // Main path: a payment-intake push bumps app.walletRefresh; re-fetch in place when it changes
+  // (a credit landed while the screen is open).
+  let seenRefresh = app.walletRefresh;
+  $effect(() => {
+    if (app.walletRefresh !== seenRefresh) {
+      seenRefresh = app.walletRefresh;
+      void load();
+    }
+  });
 
   function sourceLabel(source: string): string {
     return t(`wallet.source.${source}` as MessageKey);
@@ -69,13 +102,42 @@
   async function doBuy(p: CatalogProduct) {
     warnProduct = null;
     if (busy) return;
-    busy = true;
+    busyId = p.productId;
     try {
       wallet = await gateway.walletBuy(p.productId);
     } catch (e) {
       handleError(e);
     } finally {
-      busy = false;
+      busyId = null;
+    }
+  }
+
+  // onOrder funds a chip pack with money: it opens a pending order and sends the player to the
+  // provider's hosted-payment page. The chips are credited later, by the verified server callback;
+  // paying accepts the public offer (linked below the packs).
+  async function onOrder(p: CatalogProduct) {
+    if (busy) return;
+    busyId = p.productId;
+    try {
+      const order = await gateway.walletOrder(p.productId);
+      if (context === 'vk') {
+        // VK settles the payment in-app via the bridge; the chips arrive on the server callback.
+        await vkShowOrderBox(order.orderId);
+      } else if (context === 'telegram') {
+        // Telegram Stars: the bot minted an invoice link (returned as redirectUrl); open it in-app.
+        // The chips are credited server-side by the forwarded payment and arrive on the live push;
+        // refresh on 'paid' as a fallback. Outside a Stars-capable client, fall back to the link.
+        const opened = telegramOpenInvoice(order.redirectUrl, (status) => {
+          if (status === 'paid') void load();
+        });
+        if (!opened) openExternalUrl(order.redirectUrl);
+      } else {
+        openExternalUrl(order.redirectUrl);
+      }
+    } catch (e) {
+      handleError(e);
+    } finally {
+      busyId = null;
     }
   }
 </script>
@@ -105,11 +167,17 @@
 
   <section>
     <h3>{t('wallet.store')}</h3>
+    {#if purchaseBlocked}
+      <!-- prettier-ignore -->
+      <p class="ios-note" data-testid="ios-note">{t('wallet.iosBlockedPre')}<a href={siteRoot} target="_blank" rel="noopener noreferrer" onclick={onExternalLinkClick}>{t('wallet.iosBlockedLink')}</a>{t('wallet.iosBlockedPost')}</p>
+    {/if}
     {#each values as p (p.productId)}
       <div class="row product" data-testid="product" data-kind="value" data-pid={p.productId}>
         <span class="name">{p.title}</span>
         <span class="price">🪙 {p.chips}</span>
-        <button class="buy" data-testid="buy" disabled={busy} onclick={() => onBuy(p)}>{t('wallet.buy')}</button>
+        <button class="buy" class:working={busyId === p.productId} data-testid="buy" disabled={busy} onclick={() => onBuy(p)}
+          >{t('wallet.buy')}</button
+        >
       </div>
     {/each}
 
@@ -120,9 +188,24 @@
         <div class="row product" data-testid="product" data-kind="pack" data-pid={p.productId}>
           <span class="name">{p.title}</span>
           <span class="price">{formatAmount(p.moneyAmount, p.moneyCurrency)}&nbsp;{currencyLabel(p.moneyCurrency)}</span>
-          <button class="buy" disabled>{t('wallet.soon')}</button>
+          <button
+            class="buy"
+            class:blocked={purchaseBlocked}
+            class:working={busyId === p.productId}
+            data-testid="buy-pack"
+            disabled={busy}
+            onclick={() => {
+              if (purchaseBlocked) showToast(t('wallet.platformNoBuy'));
+              else void onOrder(p);
+            }}>{t('wallet.buy')}</button
+          >
         </div>
       {/each}
+      {#if packs.length > 0}
+        <p class="offer" data-testid="offer">
+          <a href="/offer/" target="_blank" rel="noopener noreferrer">{t('wallet.offer')}</a>
+        </p>
+      {/if}
     {/if}
 
     {#if !loading && values.length === 0 && (gpBuild || packs.length === 0)}
@@ -194,9 +277,25 @@
     cursor: pointer;
   }
   .buy:disabled {
-    opacity: 0.5;
     cursor: default;
   }
+  /* The dimmed look is scoped: the tapped button while its purchase is in flight (working), or a
+     blocked pack on VK iOS — never every buy button at once when one purchase is busy. */
+  .buy.blocked,
+  .buy.working {
+    opacity: 0.5;
+  }
+  .ios-note {
+    margin: 0 0 4px;
+    padding: 8px 12px;
+    color: var(--text-muted);
+    font-size: 0.85rem;
+    border: 1px dashed var(--border);
+    border-radius: var(--radius-sm);
+  }
+  .ios-note a {
+    color: var(--accent);
+  }
   .empty,
   .stub {
     margin: 0;
@@ -207,6 +306,14 @@
     border: 1px dashed var(--border);
     border-radius: var(--radius-sm);
   }
+  .offer {
+    margin: 2px 0 0;
+    text-align: center;
+    font-size: 0.85rem;
+  }
+  .offer a {
+    color: var(--text-muted);
+  }
   .warn-body {
     margin: 0 0 14px;
   }

ui/tsconfig.node.json

@@ -8,5 +8,5 @@
     "skipLibCheck": true,
     "types": ["node"]
   },
-  "include": ["vite.config.ts"]
+  "include": ["vite.config.ts", "src/lib/offer.ts"]
 }

ui/vite.config.ts

@@ -3,6 +3,7 @@ import { resolve } from 'node:path';
 import { defineConfig, type Plugin } from 'vite';
 import { svelte } from '@sveltejs/vite-plugin-svelte';
 import { VitePWA } from 'vite-plugin-pwa';
+import { renderOfferHtml } from './src/lib/offer';
 
 /**
  * injectBootVersion stamps the app version into index.html's boot-capability guard, replacing its
@@ -38,6 +39,22 @@ function emitPolyfills(): Plugin {
   };
 }
 
+/**
+ * emitOffer renders the public offer markdown (legal/offer_ru.md) to a standalone
+ * static page and emits it as dist/offer/index.html, which the landing container
+ * serves at /offer/ (deploy/landing/Caddyfile). The markdown is the owner-editable
+ * source of truth, so the page is regenerated from it on every build.
+ */
+function emitOffer(): Plugin {
+  return {
+    name: 'emit-offer',
+    generateBundle() {
+      const md = readFileSync(resolve(import.meta.dirname, 'legal/offer_ru.md'), 'utf8');
+      this.emitFile({ type: 'asset', fileName: 'offer/index.html', source: renderOfferHtml(md) });
+    },
+  };
+}
+
 // The edge Connect service is scrabble.edge.v1.Gateway; the gateway serves it over
 // h2c on :8081 by default. In dev we proxy the RPC path so the browser (which can
 // not speak h2c directly) talks to the dev server on the same origin. In `mock`
@@ -60,6 +77,7 @@ export default defineConfig(({ mode }) => ({
   plugins: [
     svelte(),
     emitPolyfills(),
+    emitOffer(),
     injectBootVersion(),
     // App-shell precache for the offline mode: a custom (injectManifest) service worker precaches
     // index.html + the hashed assets so the installed web PWA cold-launches with no network. It