refactor(stripe): drop dead stripeKey fields and pre-call sdk params

- Drop stripe.Key write in ReconcileStale3DSOrders; wire once in api/main.go after cfg.Load so concurrent reconcilers don't
race the SDK global.
- Add empty-PI short-circuit before paymentintent.Get to bury a future regression in a slog.Warn instead of a Stripe 4xx.
- Swap fmt.Printf for slog.Warn with k/v attrs in loadAbandoned3DSThresholdMinutes so Loki sees structured fields instead of
 literal %q/%d.
- Comment the updated_at predicate (RetryAuth bumps it via GORM auto-stamp, intentional grace-window extension) + the
conditional-UPDATE/map-form choice.
- Tests: processing/requires_capture skip, unknown-status skip, stripe-error skip, empty-PI skip, full env-parse table for
loadAbandoned3DSThresholdMinutes.

api/handlers/addresses.go

@@ -42,7 +42,7 @@ func (h *AddressHandler) GetAddresses(w http.ResponseWriter, r *http.Request) {
 	var addresses []models.Address
 	db.Where("user_id = ?", userID).Order("is_default DESC, created_at DESC").Find(&addresses)
 
-	utils.RespondSuccess(w, http.StatusOK, map[string]interface{}{
+	utils.RespondSuccess(w, http.StatusOK, map[string]any{
 		"addresses": addresses,
 	})
 }
@@ -154,7 +154,7 @@ func (h *AddressHandler) CreateAddress(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	utils.RespondSuccess(w, http.StatusCreated, map[string]interface{}{
+	utils.RespondSuccess(w, http.StatusCreated, map[string]any{
 		"address": address,
 	})
 }
@@ -183,7 +183,7 @@ func (h *AddressHandler) DeleteAddress(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	utils.RespondSuccess(w, http.StatusOK, map[string]interface{}{
+	utils.RespondSuccess(w, http.StatusOK, map[string]any{
 		"message": "address successfully deleted",
 	})
 }
@@ -218,7 +218,7 @@ func (h *AddressHandler) SetDefaultAddress(w http.ResponseWriter, r *http.Reques
 		return
 	}
 
-	utils.RespondSuccess(w, http.StatusOK, map[string]interface{}{
+	utils.RespondSuccess(w, http.StatusOK, map[string]any{
 		"address": address,
 	})
 }

api/handlers/addresses_test.go

@@ -58,7 +58,7 @@ func TestGetAddressesEmpty(t *testing.T) {
 	var resp struct {
 		Success bool `json:"success"`
 		Data    struct {
-			Addresses []interface{} `json:"addresses"`
+			Addresses []any `json:"addresses"`
 		} `json:"data"`
 	}
 	if err := json.NewDecoder(w.Body).Decode(&resp); err != nil {

api/handlers/auth.go

@@ -108,7 +108,7 @@ func (h *AuthHandler) GetToken(w http.ResponseWriter, r *http.Request) {
 	}
 
 	middleware.RecordAuthAttempt("success")
-	utils.RespondSuccess(w, http.StatusOK, map[string]interface{}{
+	utils.RespondSuccess(w, http.StatusOK, map[string]any{
 		"access_token": token,
 		"token_type":   "Bearer",
 		"expires_in":   1800, // 30 minutes in seconds
@@ -146,7 +146,7 @@ func (h *AuthHandler) RegisterWithSSHKey(w http.ResponseWriter, r *http.Request)
 	}
 
 	if len(errors) > 0 {
-		utils.RespondError(w, http.StatusBadRequest, "VALIDATION_ERROR", "validation failed", map[string]interface{}{
+		utils.RespondError(w, http.StatusBadRequest, "VALIDATION_ERROR", "validation failed", map[string]any{
 			"errors": errors,
 		})
 		return
@@ -173,7 +173,7 @@ func (h *AuthHandler) RegisterWithSSHKey(w http.ResponseWriter, r *http.Request)
 		return
 	}
 
-	utils.RespondSuccess(w, http.StatusCreated, map[string]interface{}{
+	utils.RespondSuccess(w, http.StatusCreated, map[string]any{
 		"user": user.ToPublic(),
 	})
 }
@@ -195,7 +195,7 @@ func (h *AuthHandler) GetUserBySSHKey(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	utils.RespondSuccess(w, http.StatusOK, map[string]interface{}{
+	utils.RespondSuccess(w, http.StatusOK, map[string]any{
 		"user": user.ToPublic(),
 	})
 }

api/handlers/card_test.go

@@ -46,7 +46,7 @@ func TestGetCards_FiltersExpiredRows(t *testing.T) {
 		}
 	}
 
-	handler := NewCardHandler("", "")
+	handler := NewCardHandler("")
 	req := authRequest("GET", "/api/v1/cards", nil, user.ID)
 	w := httptest.NewRecorder()
 	handler.GetCards(w, req)
@@ -91,7 +91,7 @@ func TestSetDefaultCard_ExpiredReturns410(t *testing.T) {
 		t.Fatalf("seed card: %v", err)
 	}
 
-	handler := NewCardHandler("", "")
+	handler := NewCardHandler("")
 	idStr := strconv.FormatUint(uint64(card.ID), 10)
 	req := authRequest("PUT", "/api/v1/cards/"+idStr+"/default", nil, user.ID)
 	routeCtx := chi.NewRouteContext()

api/handlers/cards.go

@@ -67,13 +67,13 @@ func PayRedirect(w http.ResponseWriter, r *http.Request) {
 
 // CardHandler handles saved payment method CRUD.
 type CardHandler struct {
-	stripeKey string
-	appURL    string
+	appURL string
 }
 
-// NewCardHandler creates a new card handler with the Stripe secret key.
-func NewCardHandler(stripeSecretKey string, appURL string) *CardHandler {
-	return &CardHandler{stripeKey: stripeSecretKey, appURL: appURL}
+// NewCardHandler creates a new card handler. Stripe credentials are wired
+// once at startup via stripe.Key in api/main.go.
+func NewCardHandler(appURL string) *CardHandler {
+	return &CardHandler{appURL: appURL}
 }
 
 // GetCards returns all saved cards for the authenticated user.
@@ -89,12 +89,12 @@ func (h *CardHandler) GetCards(w http.ResponseWriter, r *http.Request) {
 		userID, time.Now(),
 	).Order("is_default DESC, created_at DESC").Find(&cards)
 
-	utils.RespondSuccess(w, http.StatusOK, map[string]interface{}{
+	utils.RespondSuccess(w, http.StatusOK, map[string]any{
 		"cards": cards,
 	})
 }
 
-// func utils.RespondError(w http.ResponseWriter, statusCode int, code string, message string, details map[string]interface{})
+// func utils.RespondError(w http.ResponseWriter, statusCode int, code string, message string, details map[string]any)
 
 // GetCard returns a single saved card by ID.
 func (h *CardHandler) GetCard(w http.ResponseWriter, r *http.Request) {
@@ -114,7 +114,7 @@ func (h *CardHandler) GetCard(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	utils.RespondSuccess(w, http.StatusOK, map[string]interface{}{
+	utils.RespondSuccess(w, http.StatusOK, map[string]any{
 		"card": card,
 	})
 }
@@ -137,7 +137,7 @@ func (h *CardHandler) SetDefaultCard(w http.ResponseWriter, r *http.Request) {
 	}
 
 	if card.IsStorageExpired(time.Now()) {
-		if err := expireStoredCard(db, &card, h.stripeKey); err != nil {
+		if err := expireStoredCard(db, &card); err != nil {
 			utils.RespondError(w, http.StatusInternalServerError, "INTERNAL_ERROR", "failed to expire card", nil)
 			return
 		}
@@ -156,7 +156,7 @@ func (h *CardHandler) SetDefaultCard(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	utils.RespondSuccess(w, http.StatusOK, map[string]interface{}{
+	utils.RespondSuccess(w, http.StatusOK, map[string]any{
 		"card": card,
 	})
 }
@@ -171,8 +171,6 @@ func (h *CardHandler) CollectCard(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	stripe.Key = h.stripeKey
-
 	if err := ensureStripeCustomer(db, &user); err != nil {
 		utils.RespondError(w, http.StatusInternalServerError, "STRIPE_ERROR", "failed to create stripe customer", nil)
 		return
@@ -197,7 +195,7 @@ func (h *CardHandler) CollectCard(w http.ResponseWriter, r *http.Request) {
 		utils.RespondError(w, http.StatusInternalServerError, "INTERNAL_ERROR", "failed to generate redirect token", nil)
 		return
 	}
-	utils.RespondSuccess(w, http.StatusOK, map[string]interface{}{
+	utils.RespondSuccess(w, http.StatusOK, map[string]any{
 		"url": fmt.Sprintf("%s/pay/%s", h.appURL, token),
 	})
 }
@@ -234,8 +232,6 @@ func (h *CardHandler) SaveCard(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	stripe.Key = h.stripeKey
-
 	// Ensure the user has a Stripe customer, creating one if needed.
 	if err := ensureStripeCustomer(db, &user); err != nil {
 		utils.RespondError(w, http.StatusInternalServerError, "STRIPE_ERROR", "failed to create stripe customer", nil)
@@ -302,7 +298,7 @@ func (h *CardHandler) SaveCard(w http.ResponseWriter, r *http.Request) {
 
 	audit.CardAdded(userID, card.ID, card.Brand, card.Last4)
 
-	utils.RespondSuccess(w, http.StatusCreated, map[string]interface{}{
+	utils.RespondSuccess(w, http.StatusCreated, map[string]any{
 		"card": card,
 	})
 }
@@ -335,7 +331,6 @@ func (h *CardHandler) DeleteCard(w http.ResponseWriter, r *http.Request) {
 
 	// Detach from Stripe (best-effort; don't block deletion on Stripe errors).
 	if len(card.StripePaymentID) >= 3 && card.StripePaymentID[:3] == "pm_" {
-		stripe.Key = h.stripeKey
 		_, _ = paymentmethod.Detach(card.StripePaymentID, &stripe.PaymentMethodDetachParams{})
 	}
 
@@ -347,7 +342,7 @@ func (h *CardHandler) DeleteCard(w http.ResponseWriter, r *http.Request) {
 
 	audit.CardDeleted(userID, card.ID)
 
-	utils.RespondSuccess(w, http.StatusOK, map[string]interface{}{
+	utils.RespondSuccess(w, http.StatusOK, map[string]any{
 		"message": "card deleted",
 	})
 }
@@ -355,8 +350,10 @@ func (h *CardHandler) DeleteCard(w http.ResponseWriter, r *http.Request) {
 // expireStoredCard removes a card whose retention deadline elapsed.
 // Local state (cart references + card row) is committed atomically;
 // Stripe detach and audit run only after the local commit so retries
-// cannot double-fire the audit event.
-func expireStoredCard(db *gorm.DB, card *models.Card, stripeKey string) error {
+// cannot double-fire the audit event. Stripe detach is gated on
+// stripe.Key being non-empty so tests (which never init the SDK key)
+// skip the real network call without an explicit flag.
+func expireStoredCard(db *gorm.DB, card *models.Card) error {
 	if err := db.Transaction(func(tx *gorm.DB) error {
 		if err := tx.Model(&models.Cart{}).Where("card_id = ? AND user_id = ?", card.ID, card.UserID).Update("card_id", nil).Error; err != nil {
 			return fmt.Errorf("failed to clear expired card from cart: %w", err)
@@ -369,8 +366,7 @@ func expireStoredCard(db *gorm.DB, card *models.Card, stripeKey string) error {
 		return err
 	}
 
-	if stripeKey != "" && strings.HasPrefix(card.StripePaymentID, "pm_") {
-		stripe.Key = stripeKey
+	if stripe.Key != "" && strings.HasPrefix(card.StripePaymentID, "pm_") {
 		if _, err := paymentmethod.Detach(card.StripePaymentID, &stripe.PaymentMethodDetachParams{}); err != nil {
 			slog.Warn("failed to detach expired card", "card_id", card.ID, "error", err)
 		}

api/handlers/cards_expire_test.go

@@ -58,7 +58,7 @@ func TestReconcileExpiredCards_RemovesPastDeadlineOnly(t *testing.T) {
 		t.Fatalf("seed cart: %v", err)
 	}
 
-	ReconcileExpiredCards("")
+	ReconcileExpiredCards()
 
 	var remaining []models.Card
 	if err := db.Where("user_id = ?", user.ID).Find(&remaining).Error; err != nil {
@@ -117,7 +117,7 @@ func TestReconcileExpiredCards_SweepsAcrossUsers(t *testing.T) {
 		}
 	}
 
-	ReconcileExpiredCards("")
+	ReconcileExpiredCards()
 
 	var count int64
 	if err := db.Model(&models.Card{}).Count(&count).Error; err != nil {

api/handlers/cart.go

@@ -25,7 +25,6 @@ import (
 )
 
 type CartHandler struct {
-	stripeKey     string
 	appURL        string
 	maxOrderCents int
 }
@@ -36,9 +35,10 @@ type CartHandler struct {
 // audit rows (audit.EventOrderRequiresAction) so the cap stays migration-free.
 const maxAuthIssuances = 4
 
-// NewCartHandler creates a new cart handler with the Stripe secret key
-func NewCartHandler(stripeSecretKey, appURL string, maxOrderCents int) *CartHandler {
-	return &CartHandler{stripeKey: stripeSecretKey, appURL: appURL, maxOrderCents: maxOrderCents}
+// NewCartHandler creates a new cart handler. Stripe credentials are wired
+// once at startup via stripe.Key in api/main.go.
+func NewCartHandler(appURL string, maxOrderCents int) *CartHandler {
+	return &CartHandler{appURL: appURL, maxOrderCents: maxOrderCents}
 }
 
 // getOrCreateCart finds the users cart or creates one.
@@ -55,18 +55,18 @@ func getOrCreateCart(ctx context.Context, userID uint) (*models.Cart, error) {
 	return &cart, nil
 }
 
-func cartResponse(ctx context.Context, cart *models.Cart) map[string]interface{} {
+func cartResponse(ctx context.Context, cart *models.Cart) map[string]any {
 	db := database.GetDB().WithContext(ctx)
 
 	var items []models.CartItem
 	db.Where("cart_id = ? AND quantity > 0", cart.ID).Preload("Coffee").Find(&items)
 
 	subtotal := 0
-	itemsData := make([]map[string]interface{}, 0, len(items))
+	itemsData := make([]map[string]any, 0, len(items))
 	for _, item := range items {
 		lineTotal := item.Coffee.Price * item.Quantity
 		subtotal += lineTotal
-		itemsData = append(itemsData, map[string]interface{}{
+		itemsData = append(itemsData, map[string]any{
 			"id":        item.ID,
 			"coffee_id": item.CoffeeID,
 			"quantity":  item.Quantity,
@@ -75,7 +75,7 @@ func cartResponse(ctx context.Context, cart *models.Cart) map[string]interface{}
 		})
 	}
 
-	return map[string]interface{}{
+	return map[string]any{
 		"items":            itemsData,
 		"subtotal":         subtotal,
 		"address_id":       cart.AddressID,
@@ -94,7 +94,7 @@ func (h *CartHandler) GetCart(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	utils.RespondSuccess(w, http.StatusOK, map[string]interface{}{
+	utils.RespondSuccess(w, http.StatusOK, map[string]any{
 		"cart": cartResponse(r.Context(), cart),
 	})
 }
@@ -157,7 +157,7 @@ func (h *CartHandler) SetItem(w http.ResponseWriter, r *http.Request) {
 		}
 	}
 
-	utils.RespondSuccess(w, http.StatusOK, map[string]interface{}{
+	utils.RespondSuccess(w, http.StatusOK, map[string]any{
 		"cart": cartResponse(r.Context(), cart),
 	})
 }
@@ -193,7 +193,7 @@ func (h *CartHandler) SetAddress(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	utils.RespondSuccess(w, http.StatusOK, map[string]interface{}{
+	utils.RespondSuccess(w, http.StatusOK, map[string]any{
 		"message": "address set",
 	})
 }
@@ -219,7 +219,7 @@ func (h *CartHandler) SetCard(w http.ResponseWriter, r *http.Request) {
 	}
 
 	if card.IsStorageExpired(time.Now()) {
-		if err := expireStoredCard(db, &card, h.stripeKey); err != nil {
+		if err := expireStoredCard(db, &card); err != nil {
 			utils.RespondError(w, http.StatusInternalServerError, "INTERNAL_ERROR", "failed to expire card", nil)
 			return
 		}
@@ -238,7 +238,7 @@ func (h *CartHandler) SetCard(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	utils.RespondSuccess(w, http.StatusOK, map[string]interface{}{
+	utils.RespondSuccess(w, http.StatusOK, map[string]any{
 		"message": "card set",
 	})
 }
@@ -258,7 +258,7 @@ func (h *CartHandler) ClearCart(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	utils.RespondSuccess(w, http.StatusOK, map[string]interface{}{
+	utils.RespondSuccess(w, http.StatusOK, map[string]any{
 		"message": "cart cleared",
 	})
 }
@@ -315,7 +315,7 @@ func (h *CartHandler) ConvertCart(w http.ResponseWriter, r *http.Request) {
 
 	if card.IsStorageExpired(time.Now()) {
 		middleware.RecordCartConversion("validation_card_expired")
-		if err := expireStoredCard(db, &card, h.stripeKey); err != nil {
+		if err := expireStoredCard(db, &card); err != nil {
 			utils.RespondError(w, http.StatusInternalServerError, "INTERNAL_ERROR", "failed to expire card", nil)
 			return
 		}
@@ -330,8 +330,6 @@ func (h *CartHandler) ConvertCart(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	stripe.Key = h.stripeKey
-
 	// Ensure the user has a Stripe customer (shared helper with cards handler).
 	if err := ensureStripeCustomer(db, &user); err != nil {
 		middleware.RecordCartConversion("stripe_customer_failed")
@@ -386,7 +384,7 @@ func (h *CartHandler) ConvertCart(w http.ResponseWriter, r *http.Request) {
 		middleware.RecordCartConversion("validation_over_limit")
 		utils.RespondError(w, http.StatusBadRequest, "CART_OVER_LIMIT",
 			fmt.Sprintf("order total must be at most $%.2f", float64(h.maxOrderCents)/100),
-			map[string]interface{}{
+			map[string]any{
 				"total_cents": total,
 				"limit_cents": h.maxOrderCents,
 			})
@@ -507,7 +505,7 @@ func (h *CartHandler) ConvertCart(w http.ResponseWriter, r *http.Request) {
 		if err := tx.Where("cart_id = ?", cart.ID).Delete(&models.CartItem{}).Error; err != nil {
 			return err
 		}
-		return tx.Model(cart).Updates(map[string]interface{}{
+		return tx.Model(cart).Updates(map[string]any{
 			"address_id": nil,
 			"card_id":    nil,
 		}).Error
@@ -534,14 +532,15 @@ func (h *CartHandler) ConvertCart(w http.ResponseWriter, r *http.Request) {
 	}
 	go notify.SlackOrderPaid(&order)
 
-	utils.RespondSuccess(w, http.StatusOK, map[string]interface{}{
+	utils.RespondSuccess(w, http.StatusOK, map[string]any{
 		"order": order,
 	})
 }
 
-// respondRequiresAction handles a PaymentIntent that needs 3DS auth
-// The order stays pending. the webhook flips it to paid once the customer
-// completes the bank-hosted challenge, the tui polls /api/v1/orders/{id}/status
+// respondRequiresAction handles a PaymentIntent that needs 3DS auth. The order
+// transitions to requires_action (see caveat #20 in sca-psd2-compliance.md);
+// the payment_intent.succeeded webhook flips it to paid once the customer
+// completes the bank-hosted challenge. The TUI polls /api/v1/orders/{id}/status.
 func (h *CartHandler) respondRequiresAction(w http.ResponseWriter, order *models.Order, paymentMethodID string, pi *stripe.PaymentIntent) {
 	db := database.GetDB()
 
@@ -568,13 +567,15 @@ func (h *CartHandler) respondRequiresAction(w http.ResponseWriter, order *models
 		return
 	}
 
-	// Persist the paymentIntent id AND reset status to pending. The
-	// payment_intent.payment_failed webhook from the initial off-session decline
-	// often arrives before this response and flips the order to failed —
-	// override it back so the 3DS-in-flight order shows the correct state.
+	// Persist the paymentIntent id AND set status to requires_action so list
+	// UIs can distinguish "charging" from "awaiting customer 3DS". The
+	// payment_intent.payment_failed webhook from the initial off-session
+	// decline often arrives before this response and flips the order to
+	// failed - override it back so the 3DS-in-flight order shows the
+	// correct state
 	if err := db.Model(order).Updates(map[string]any{
 		"stripe_payment_id": pi.ID,
-		"status":            models.OrderStatusPending,
+		"status":            models.OrderStatusRequiresAction,
 	}).Error; err != nil {
 		utils.RespondError(w, http.StatusInternalServerError, "DATABASE_ERROR", "failed to save payment id", nil)
 		return
@@ -658,10 +659,14 @@ func (h *CartHandler) RetryAuth(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	// Only pending (initial attempt mid-flight) and failed (webhook flipped it
-	// after a non-recoverable error) are retryable. paid, refundedn shipped,
-	// delivered, cancelled are terminal - refuse
-	if order.Status != models.OrderStatusPending && order.Status != models.OrderStatusFailed {
+	// Retryable source states:
+	//	pending 		- initial attempt mid-flight (pre-PI confirm page)
+	//	requires_action - customer abandoned or failed the 3DS challenge
+	//	failed 			- webhook flipped after a non-recoverable error
+	// terminal states (paid, shipped, delivered, cancelled, refunded) refuse.
+	if order.Status != models.OrderStatusPending &&
+		order.Status != models.OrderStatusRequiresAction &&
+		order.Status != models.OrderStatusFailed {
 		utils.RespondError(w, http.StatusConflict, "INVALID_STATE", "order is already finalized", nil)
 		return
 	}
@@ -699,7 +704,7 @@ func (h *CartHandler) RetryAuth(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 	if card.IsStorageExpired(time.Now()) {
-		if err := expireStoredCard(db, &card, h.stripeKey); err != nil {
+		if err := expireStoredCard(db, &card); err != nil {
 			utils.RespondError(w, http.StatusInternalServerError, "INTERNAL_ERROR", "failed to expire card", nil)
 			return
 		}
@@ -707,8 +712,6 @@ func (h *CartHandler) RetryAuth(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	stripe.Key = h.stripeKey
-
 	stripeStart := time.Now()
 	confirmed, cerr := paymentintent.Confirm(order.StripePaymentID, &stripe.PaymentIntentConfirmParams{
 		PaymentMethod: stripe.String(card.StripePaymentID),

api/handlers/cart_test.go

@@ -11,6 +11,7 @@ import (
 	"time"
 
 	"github.com/go-chi/chi/v5"
+	"github.com/stripe/stripe-go/v78"
 
 	"terminalShop/api/middleware"
 	"terminalShop/pkg/audit"
@@ -68,7 +69,7 @@ func TestGetCartEmpty(t *testing.T) {
 	defer func() { _ = os.Remove(testDB) }()
 	defer database.ResetForTesting()
 
-	handler := NewCartHandler("", "", 0)
+	handler := NewCartHandler("", 0)
 
 	req := authRequest("GET", "/api/v1/cart", nil, user.ID)
 	w := httptest.NewRecorder()
@@ -83,8 +84,8 @@ func TestGetCartEmpty(t *testing.T) {
 		Success bool `json:"success"`
 		Data    struct {
 			Cart struct {
-				Items    []interface{} `json:"items"`
-				Subtotal int           `json:"subtotal"`
+				Items    []any `json:"items"`
+				Subtotal int   `json:"subtotal"`
 			} `json:"cart"`
 		} `json:"data"`
 	}
@@ -107,10 +108,10 @@ func TestSetItemAndGetCart(t *testing.T) {
 	defer func() { _ = os.Remove(testDB) }()
 	defer database.ResetForTesting()
 
-	handler := NewCartHandler("", "", 0)
+	handler := NewCartHandler("", 0)
 
 	// Add item (CoffeeID=1, Quantity=2)
-	body, _ := json.Marshal(map[string]interface{}{
+	body, _ := json.Marshal(map[string]any{
 		"coffee_id": 1,
 		"quantity":  2,
 	})
@@ -163,16 +164,16 @@ func TestSetItemUpdateQuantity(t *testing.T) {
 	defer func() { _ = os.Remove(testDB) }()
 	defer database.ResetForTesting()
 
-	handler := NewCartHandler("", "", 0)
+	handler := NewCartHandler("", 0)
 
 	// Add item
-	body, _ := json.Marshal(map[string]interface{}{"coffee_id": 1, "quantity": 2})
+	body, _ := json.Marshal(map[string]any{"coffee_id": 1, "quantity": 2})
 	req := authRequest("PUT", "/api/v1/cart/item", body, user.ID)
 	w := httptest.NewRecorder()
 	handler.SetItem(w, req)
 
 	// Update quantity
-	body, _ = json.Marshal(map[string]interface{}{"coffee_id": 1, "quantity": 5})
+	body, _ = json.Marshal(map[string]any{"coffee_id": 1, "quantity": 5})
 	req = authRequest("PUT", "/api/v1/cart/item", body, user.ID)
 	w = httptest.NewRecorder()
 	handler.SetItem(w, req)
@@ -208,16 +209,16 @@ func TestSetItemRemove(t *testing.T) {
 	defer func() { _ = os.Remove(testDB) }()
 	defer database.ResetForTesting()
 
-	handler := NewCartHandler("", "", 0)
+	handler := NewCartHandler("", 0)
 
 	// Add item
-	body, _ := json.Marshal(map[string]interface{}{"coffee_id": 1, "quantity": 3})
+	body, _ := json.Marshal(map[string]any{"coffee_id": 1, "quantity": 3})
 	req := authRequest("PUT", "/api/v1/cart/item", body, user.ID)
 	w := httptest.NewRecorder()
 	handler.SetItem(w, req)
 
 	// Remove item (quantity 0)
-	body, _ = json.Marshal(map[string]interface{}{"coffee_id": 1, "quantity": 0})
+	body, _ = json.Marshal(map[string]any{"coffee_id": 1, "quantity": 0})
 	req = authRequest("PUT", "/api/v1/cart/item", body, user.ID)
 	w = httptest.NewRecorder()
 	handler.SetItem(w, req)
@@ -231,7 +232,7 @@ func TestSetItemRemove(t *testing.T) {
 		Success bool `json:"success"`
 		Data    struct {
 			Cart struct {
-				Items []interface{} `json:"items"`
+				Items []any `json:"items"`
 			} `json:"cart"`
 		} `json:"data"`
 	}
@@ -247,9 +248,9 @@ func TestSetItemInvalidProduct(t *testing.T) {
 	defer func() { _ = os.Remove(testDB) }()
 	defer database.ResetForTesting()
 
-	handler := NewCartHandler("", "", 0)
+	handler := NewCartHandler("", 0)
 
-	body, _ := json.Marshal(map[string]interface{}{"coffee_id": 999, "quantity": 1})
+	body, _ := json.Marshal(map[string]any{"coffee_id": 999, "quantity": 1})
 	req := authRequest("PUT", "/api/v1/cart/item", body, user.ID)
 	w := httptest.NewRecorder()
 	handler.SetItem(w, req)
@@ -264,9 +265,9 @@ func TestSetItemMissingCoffeeID(t *testing.T) {
 	defer func() { _ = os.Remove(testDB) }()
 	defer database.ResetForTesting()
 
-	handler := NewCartHandler("", "", 0)
+	handler := NewCartHandler("", 0)
 
-	body, _ := json.Marshal(map[string]interface{}{"quantity": 1})
+	body, _ := json.Marshal(map[string]any{"quantity": 1})
 	req := authRequest("PUT", "/api/v1/cart/item", body, user.ID)
 	w := httptest.NewRecorder()
 	handler.SetItem(w, req)
@@ -281,11 +282,11 @@ func TestClearCart(t *testing.T) {
 	defer func() { _ = os.Remove(testDB) }()
 	defer database.ResetForTesting()
 
-	handler := NewCartHandler("", "", 0)
+	handler := NewCartHandler("", 0)
 
 	// Add two items
 	for _, coffeeID := range []uint{1, 2} {
-		body, _ := json.Marshal(map[string]interface{}{"coffee_id": coffeeID, "quantity": 1})
+		body, _ := json.Marshal(map[string]any{"coffee_id": coffeeID, "quantity": 1})
 		req := authRequest("PUT", "/api/v1/cart/item", body, user.ID)
 		w := httptest.NewRecorder()
 		handler.SetItem(w, req)
@@ -309,7 +310,7 @@ func TestClearCart(t *testing.T) {
 		Success bool `json:"success"`
 		Data    struct {
 			Cart struct {
-				Items []interface{} `json:"items"`
+				Items []any `json:"items"`
 			} `json:"cart"`
 		} `json:"data"`
 	}
@@ -337,9 +338,9 @@ func TestSetAddress(t *testing.T) {
 	}
 	db.Create(&addr)
 
-	handler := NewCartHandler("", "", 0)
+	handler := NewCartHandler("", 0)
 
-	body, _ := json.Marshal(map[string]interface{}{"address_id": addr.ID})
+	body, _ := json.Marshal(map[string]any{"address_id": addr.ID})
 	req := authRequest("PUT", "/api/v1/cart/address", body, user.ID)
 	w := httptest.NewRecorder()
 	handler.SetAddress(w, req)
@@ -391,9 +392,9 @@ func TestSetAddressWrongUser(t *testing.T) {
 	}
 	db.Create(&addr)
 
-	handler := NewCartHandler("", "", 0)
+	handler := NewCartHandler("", 0)
 
-	body, _ := json.Marshal(map[string]interface{}{"address_id": addr.ID})
+	body, _ := json.Marshal(map[string]any{"address_id": addr.ID})
 	req := authRequest("PUT", "/api/v1/cart/address", body, user.ID)
 	w := httptest.NewRecorder()
 	handler.SetAddress(w, req)
@@ -419,9 +420,9 @@ func TestSetCard(t *testing.T) {
 	}
 	db.Create(&card)
 
-	handler := NewCartHandler("", "", 0)
+	handler := NewCartHandler("", 0)
 
-	body, _ := json.Marshal(map[string]interface{}{"card_id": card.ID})
+	body, _ := json.Marshal(map[string]any{"card_id": card.ID})
 	req := authRequest("PUT", "/api/v1/cart/card", body, user.ID)
 	w := httptest.NewRecorder()
 	handler.SetCard(w, req)
@@ -471,9 +472,9 @@ func TestSetCardWrongUser(t *testing.T) {
 	}
 	db.Create(&card)
 
-	handler := NewCartHandler("", "", 0)
+	handler := NewCartHandler("", 0)
 
-	body, _ := json.Marshal(map[string]interface{}{"card_id": card.ID})
+	body, _ := json.Marshal(map[string]any{"card_id": card.ID})
 	req := authRequest("PUT", "/api/v1/cart/card", body, user.ID)
 	w := httptest.NewRecorder()
 	handler.SetCard(w, req)
@@ -488,10 +489,10 @@ func TestConvertCartMissingAddress(t *testing.T) {
 	defer func() { _ = os.Remove(testDB) }()
 	defer database.ResetForTesting()
 
-	handler := NewCartHandler("", "", 0)
+	handler := NewCartHandler("", 0)
 
 	// Add item but no address or card
-	body, _ := json.Marshal(map[string]interface{}{"coffee_id": 1, "quantity": 1})
+	body, _ := json.Marshal(map[string]any{"coffee_id": 1, "quantity": 1})
 	req := authRequest("PUT", "/api/v1/cart/item", body, user.ID)
 	w := httptest.NewRecorder()
 	handler.SetItem(w, req)
@@ -511,18 +512,18 @@ func TestConvertCartMissingCard(t *testing.T) {
 	defer func() { _ = os.Remove(testDB) }()
 	defer database.ResetForTesting()
 
-	handler := NewCartHandler("", "", 0)
+	handler := NewCartHandler("", 0)
 	db := database.GetDB()
 
 	// Add item and address
-	body, _ := json.Marshal(map[string]interface{}{"coffee_id": 1, "quantity": 1})
+	body, _ := json.Marshal(map[string]any{"coffee_id": 1, "quantity": 1})
 	req := authRequest("PUT", "/api/v1/cart/item", body, user.ID)
 	w := httptest.NewRecorder()
 	handler.SetItem(w, req)
 
 	addr := models.Address{UserID: user.ID, Name: "Test", Street: "123 St", City: "PDX", State: "OR", Zip: "97201", Country: "US"}
 	db.Create(&addr)
-	body, _ = json.Marshal(map[string]interface{}{"address_id": addr.ID})
+	body, _ = json.Marshal(map[string]any{"address_id": addr.ID})
 	req = authRequest("PUT", "/api/v1/cart/address", body, user.ID)
 	w = httptest.NewRecorder()
 	handler.SetAddress(w, req)
@@ -542,7 +543,7 @@ func TestConvertCartEmpty(t *testing.T) {
 	defer func() { _ = os.Remove(testDB) }()
 	defer database.ResetForTesting()
 
-	handler := NewCartHandler("", "", 0)
+	handler := NewCartHandler("", 0)
 
 	// Empty cart convert
 	req := authRequest("POST", "/api/v1/cart/convert", nil, user.ID)
@@ -559,11 +560,11 @@ func TestMultipleItems(t *testing.T) {
 	defer func() { _ = os.Remove(testDB) }()
 	defer database.ResetForTesting()
 
-	handler := NewCartHandler("", "", 0)
+	handler := NewCartHandler("", 0)
 
 	// Add three different items
 	for i := uint(1); i <= 3; i++ {
-		body, _ := json.Marshal(map[string]interface{}{"coffee_id": i, "quantity": int(i)})
+		body, _ := json.Marshal(map[string]any{"coffee_id": i, "quantity": int(i)})
 		req := authRequest("PUT", "/api/v1/cart/item", body, user.ID)
 		w := httptest.NewRecorder()
 		handler.SetItem(w, req)
@@ -581,8 +582,8 @@ func TestMultipleItems(t *testing.T) {
 		Success bool `json:"success"`
 		Data    struct {
 			Cart struct {
-				Items    []interface{} `json:"items"`
-				Subtotal int           `json:"subtotal"`
+				Items    []any `json:"items"`
+				Subtotal int   `json:"subtotal"`
 			} `json:"cart"`
 		} `json:"data"`
 	}
@@ -608,19 +609,19 @@ func TestCartIsolation(t *testing.T) {
 	}
 	db.Create(&user2)
 
-	handler := NewCartHandler("", "", 0)
+	handler := NewCartHandler("", 0)
 	r := chi.NewRouter()
 	r.Put("/cart/item", handler.SetItem)
 	r.Get("/cart", handler.GetCart)
 
 	// User 1 adds item
-	body, _ := json.Marshal(map[string]interface{}{"coffee_id": 1, "quantity": 5})
+	body, _ := json.Marshal(map[string]any{"coffee_id": 1, "quantity": 5})
 	req := authRequest("PUT", "/cart/item", body, user1.ID)
 	w := httptest.NewRecorder()
 	r.ServeHTTP(w, req)
 
 	// User 2 adds different item
-	body, _ = json.Marshal(map[string]interface{}{"coffee_id": 2, "quantity": 3})
+	body, _ = json.Marshal(map[string]any{"coffee_id": 2, "quantity": 3})
 	req = authRequest("PUT", "/cart/item", body, user2.ID)
 	w = httptest.NewRecorder()
 	r.ServeHTTP(w, req)
@@ -709,9 +710,17 @@ func TestConvertCartLimit(t *testing.T) {
 				t.Fatalf("seed card: %v", err)
 			}
 
-			handler := NewCartHandler("", "", tc.capCents)
+			// Pin coffee_id=4's price so cart-cap math stays stable across
+			// seed-price changes. The cap test is about (price * quantity)
+			// vs cap, not which coffee or what the menu currently charges.
+			const pinnedPrice = 500
+			if err := db.Model(&models.Coffee{}).Where("id = ?", 4).Update("price", pinnedPrice).Error; err != nil {
+				t.Fatalf("pin coffee price: %v", err)
+			}
 
-			body, _ := json.Marshal(map[string]interface{}{"coffee_id": 4, "quantity": tc.quantity})
+			handler := NewCartHandler("", tc.capCents)
+
+			body, _ := json.Marshal(map[string]any{"coffee_id": 4, "quantity": tc.quantity})
 			req := authRequest("PUT", "/api/v1/cart/item", body, user.ID)
 			w := httptest.NewRecorder()
 			handler.SetItem(w, req)
@@ -720,7 +729,7 @@ func TestConvertCartLimit(t *testing.T) {
 			}
 
 			// set address
-			body, _ = json.Marshal(map[string]interface{}{"address_id": addr.ID})
+			body, _ = json.Marshal(map[string]any{"address_id": addr.ID})
 			req = authRequest("PUT", "/api/v1/cart/address", body, user.ID)
 			w = httptest.NewRecorder()
 			handler.SetAddress(w, req)
@@ -729,7 +738,7 @@ func TestConvertCartLimit(t *testing.T) {
 			}
 
 			// set card
-			body, _ = json.Marshal(map[string]interface{}{"card_id": card.ID})
+			body, _ = json.Marshal(map[string]any{"card_id": card.ID})
 			req = authRequest("PUT", "/api/v1/cart/card", body, user.ID)
 			w = httptest.NewRecorder()
 			handler.SetCard(w, req)
@@ -745,9 +754,9 @@ func TestConvertCartLimit(t *testing.T) {
 			var resp struct {
 				Success bool `json:"success"`
 				Error   struct {
-					Code    string                 `json:"code"`
-					Message string                 `json:"message"`
-					Details map[string]interface{} `json:"details"`
+					Code    string         `json:"code"`
+					Message string         `json:"message"`
+					Details map[string]any `json:"details"`
 				} `json:"error"`
 			}
 			_ = json.NewDecoder(w.Body).Decode(&resp)
@@ -760,8 +769,8 @@ func TestConvertCartLimit(t *testing.T) {
 				if got, _ := resp.Error.Details["limit_cents"].(float64); int(got) != tc.capCents {
 					t.Errorf("limit_cents in details: want %d, got %v", tc.capCents, resp.Error.Details["limit_cents"])
 				}
-				if got, _ := resp.Error.Details["total_cents"].(float64); int(got) != tc.quantity*500 {
-					t.Errorf("total_cents in details: want %d, got %v", tc.quantity*500, resp.Error.Details["total_cents"])
+				if got, _ := resp.Error.Details["total_cents"].(float64); int(got) != tc.quantity*pinnedPrice {
+					t.Errorf("total_cents in details: want %d, got %v", tc.quantity*pinnedPrice, resp.Error.Details["total_cents"])
 				}
 			}
 		})
@@ -786,8 +795,8 @@ func TestSetCard_ExpiredReturns410(t *testing.T) {
 		t.Fatalf("seed card: %v", err)
 	}
 
-	handler := NewCartHandler("", "", 0)
-	body, _ := json.Marshal(map[string]interface{}{"card_id": card.ID})
+	handler := NewCartHandler("", 0)
+	body, _ := json.Marshal(map[string]any{"card_id": card.ID})
 	req := authRequest("PUT", "/api/v1/cart/card", body, user.ID)
 	w := httptest.NewRecorder()
 	handler.SetCard(w, req)
@@ -824,20 +833,20 @@ func TestConvertCart_ExpiredReturns410(t *testing.T) {
 
 	db := database.GetDB()
 
-	body, _ := json.Marshal(map[string]interface{}{"coffee_id": 1, "quantity": 1})
+	body, _ := json.Marshal(map[string]any{"coffee_id": 1, "quantity": 1})
 	req := authRequest("PUT", "/api/v1/vart/item", body, user.ID)
 	w := httptest.NewRecorder()
-	NewCartHandler("", "", 0).SetItem(w, req)
+	NewCartHandler("", 0).SetItem(w, req)
 
 	addr := models.Address{
 		UserID: user.ID, Name: "Test", Street: "123 St",
 		City: "PDX", State: "OR", Zip: "97201", Country: "US",
 	}
 	db.Create(&addr)
-	body, _ = json.Marshal(map[string]interface{}{"address_id": addr.ID})
+	body, _ = json.Marshal(map[string]any{"address_id": addr.ID})
 	req = authRequest("PUT", "/api/v1/cart/address", body, user.ID)
 	w = httptest.NewRecorder()
-	NewCartHandler("", "", 0).SetAddress(w, req)
+	NewCartHandler("", 0).SetAddress(w, req)
 
 	past := time.Now().Add(-1 * time.Hour)
 	card := models.Card{
@@ -853,7 +862,7 @@ func TestConvertCart_ExpiredReturns410(t *testing.T) {
 
 	req = authRequest("POST", "/api/v1/cart/convert", nil, user.ID)
 	w = httptest.NewRecorder()
-	NewCartHandler("", "", 0).ConvertCart(w, req)
+	NewCartHandler("", 0).ConvertCart(w, req)
 
 	if w.Code != http.StatusGone {
 		t.Fatalf("want 410, got %d, body: %s", w.Code, w.Body.String())
@@ -875,8 +884,9 @@ func TestConvertCart_ExpiredReturns410(t *testing.T) {
 // succeeded) hit the live Stripe API and aren't covered here — see
 // sca-psd2-compliance.md "Test plan" for manual coverage with the
 // 4000 0027 6000 3184 test card. Caveat #14 in that doc still applies:
-// NewCartHandler takes 3 args and the seeded user must have a non-empty
-// StripeCustomerID so the Convert/Retry paths stay hermetic.
+// NewCartHandler takes 2 args (appURL, maxOrderCents) and the seeded user
+// must have a non-empty StripeCustomerID so the Convert/Retry paths stay
+// hermetic.
 func TestRetryAuth(t *testing.T) {
 	cases := []struct {
 		name        string
@@ -911,6 +921,12 @@ func TestRetryAuth(t *testing.T) {
 			seedPayment: "pi_test_refunded", seedEvents: 1,
 			wantStatus: http.StatusConflict, wantErrCode: "INVALID_STATE",
 		},
+		{
+			name:        "requires_action honors retry cap",
+			ownedByUser: true, seedStatus: models.OrderStatusRequiresAction,
+			seedPayment: "pi_test_req_action_cap", seedEvents: maxAuthIssuances,
+			wantStatus: http.StatusTooManyRequests, wantErrCode: "RETRY_LIMIT",
+		},
 		{
 			name:        "retry cap reached returns 429",
 			ownedByUser: true, seedStatus: models.OrderStatusFailed,
@@ -977,7 +993,7 @@ func TestRetryAuth(t *testing.T) {
 				}
 			}
 
-			handler := NewCartHandler("", "http://localhost", 0)
+			handler := NewCartHandler("http://localhost", 0)
 			req := orderRequest("POST",
 				fmt.Sprintf("/api/v1/orders/%d/retry-auth", order.ID), nil, user.ID, fmt.Sprintf("%d", order.ID))
 			w := httptest.NewRecorder()
@@ -1005,7 +1021,7 @@ func TestRetryAuth_OrderNotFound(t *testing.T) {
 	defer func() { _ = os.Remove(testDB) }()
 	defer database.ResetForTesting()
 
-	handler := NewCartHandler("", "http://localhost", 0)
+	handler := NewCartHandler("http://localhost", 0)
 	req := orderRequest("POST", "/api/v1/orders/9999/retry-auth", nil, user.ID, "9999")
 	w := httptest.NewRecorder()
 	handler.RetryAuth(w, req)
@@ -1014,3 +1030,137 @@ func TestRetryAuth_OrderNotFound(t *testing.T) {
 		t.Fatalf("want 404, got %d body=%s", w.Code, w.Body.String())
 	}
 }
+
+func TestRespondRequiresAction_SetStatusRequiresAction(t *testing.T) {
+	testDB, user := setupCartTestDB(t)
+	defer func() { _ = os.Remove(testDB) }()
+	defer database.ResetForTesting()
+
+	db := database.GetDB()
+	card := models.Card{
+		UserID: user.ID, StripePaymentID: "pm_test_req_action",
+		Last4: "4242", Brand: "Visa", ExpMonth: 12, ExpYear: 2030,
+	}
+	if err := db.Create(&card).Error; err != nil {
+		t.Fatalf("seed card: %v", err)
+	}
+
+	order := models.Order{
+		UserID: user.ID, CardID: card.ID,
+		Status:   models.OrderStatusPending,
+		Subtotal: 500, Total: 500,
+		ShippingName: "Test", ShippingStreet: "1 Main St",
+		ShippingCity: "PDX", ShippingState: "OR",
+		ShippingZip: "97201", ShippingCountry: "US",
+	}
+	if err := db.Create(&order).Error; err != nil {
+		t.Fatalf("seed order: %v", err)
+	}
+
+	pi := &stripe.PaymentIntent{
+		ID: "pi_test_action_set",
+		NextAction: &stripe.PaymentIntentNextAction{
+			RedirectToURL: &stripe.PaymentIntentNextActionRedirectToURL{
+				URL: "https://hooks.stripe.com/redirect/test/test_3ds",
+			},
+		},
+	}
+
+	handler := NewCartHandler("http://localhost", 0)
+	w := httptest.NewRecorder()
+	handler.respondRequiresAction(w, &order, card.StripePaymentID, pi)
+
+	if w.Code != http.StatusAccepted {
+		t.Fatalf("want 202, got %d body=%s", w.Code, w.Body.String())
+	}
+
+	var resp struct {
+		Data struct {
+			OrderID         uint   `json:"order_id"`
+			PaymentIntentID string `json:"payment_intent_id"`
+			Status          string `json:"status"`
+			RedirectURL     string `json:"redirect_url"`
+		} `json:"data"`
+	}
+	if err := json.NewDecoder(w.Body).Decode(&resp); err != nil {
+		t.Fatalf("decode response: %v", err)
+	}
+	if resp.Data.Status != "requires_action" {
+		t.Fatalf("response status: %q, got %q", "requires_action", resp.Data.Status)
+	}
+	if resp.Data.RedirectURL == "" {
+		t.Fatalf("expected redirect url, got empty")
+	}
+	if resp.Data.PaymentIntentID != pi.ID {
+		t.Fatalf("payment intent id: want %q, got %q", pi.ID, resp.Data.PaymentIntentID)
+	}
+
+	var reloaded models.Order
+	if err := db.First(&reloaded, order.ID).Error; err != nil {
+		t.Fatalf("reload order: %v", err)
+	}
+	if reloaded.Status != models.OrderStatusRequiresAction {
+		t.Fatalf("order.Status: want %q, got %q", models.OrderStatusRequiresAction, reloaded.Status)
+	}
+	if reloaded.StripePaymentID != pi.ID {
+		t.Fatalf("order.StripePaymentID: want %q, got %q", pi.ID, reloaded.StripePaymentID)
+	}
+}
+
+// TestRespondRequiresAction_OverridesFailedFromWebhookRace simulates the race
+// described in sca-psd2-compliance.md note #3 / caveat #4: the
+// payment_intent.payment_failed webhook arrives BEFORE respondRequiresAction
+// returns and flips the row to OrderStatusFailed. The helper must override
+// that back to OrderStatusRequiresAction so the in-flight 3DS state surfaces
+// correctly to the TUI.
+func TestRespondRequiresAction_OverridesFailedFromWebhookRace(t *testing.T) {
+	testDB, user := setupCartTestDB(t)
+	defer func() { _ = os.Remove(testDB) }()
+	defer database.ResetForTesting()
+
+	db := database.GetDB()
+	card := models.Card{
+		UserID: user.ID, StripePaymentID: "pm_test_race",
+		Last4: "4242", Brand: "Visa", ExpMonth: 12, ExpYear: 2030,
+	}
+	if err := db.Create(&card).Error; err != nil {
+		t.Fatalf("seed card: %v", err)
+	}
+
+	order := models.Order{
+		UserID: user.ID, CardID: card.ID,
+		Status:   models.OrderStatusFailed,
+		Subtotal: 500, Total: 500,
+		ShippingName: "Test", ShippingStreet: "1 Main St",
+		ShippingCity: "PDX", ShippingState: "OR",
+		ShippingZip: "97201", ShippingCountry: "US",
+	}
+	if err := db.Create(&order).Error; err != nil {
+		t.Fatalf("seed order: %v", err)
+	}
+
+	pi := &stripe.PaymentIntent{
+		ID: "pi_test_race",
+		NextAction: &stripe.PaymentIntentNextAction{
+			RedirectToURL: &stripe.PaymentIntentNextActionRedirectToURL{
+				URL: "https://hooks.stripe.com/redirect/test_race",
+			},
+		},
+	}
+
+	handler := NewCartHandler("http://localhost", 0)
+	w := httptest.NewRecorder()
+	handler.respondRequiresAction(w, &order, card.StripePaymentID, pi)
+
+	if w.Code != http.StatusAccepted {
+		t.Fatalf("want 202, got %d body=%s", w.Code, w.Body.String())
+	}
+
+	var reloaded models.Order
+	if err := db.First(&reloaded, order.ID).Error; err != nil {
+		t.Fatalf("reload order: %v", err)
+	}
+	if reloaded.Status != models.OrderStatusRequiresAction {
+		t.Fatalf("override failed: want %q, got %q", models.OrderStatusRequiresAction, reloaded.Status)
+	}
+}

api/handlers/orders.go

@@ -28,7 +28,6 @@ import (
 )
 
 type OrderHandler struct {
-	stripeKey           string
 	bringAPIUID         string
 	bringAPIKey         string
 	bringCustomerNumber string
@@ -44,9 +43,10 @@ type refundRequestPayload struct {
 // repeated submissions from spamming the operator's Slack channel.
 const refundRequestCooldown = 15 * time.Minute
 
-func NewOrderHandler(stripeSecretKey, bringAPIUID, bringAPIKey, bringCustomerNumber string) *OrderHandler {
+// NewOrderHandler creates an order handler. Stripe credentials are wired
+// once at startup via stripe.Key in api/main.go.
+func NewOrderHandler(bringAPIUID, bringAPIKey, bringCustomerNumber string) *OrderHandler {
 	return &OrderHandler{
-		stripeKey:           stripeSecretKey,
 		bringAPIUID:         bringAPIUID,
 		bringAPIKey:         bringAPIKey,
 		bringCustomerNumber: bringCustomerNumber,
@@ -200,8 +200,6 @@ func (h *OrderHandler) RefundOrder(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	stripe.Key = h.stripeKey
-
 	rf, err := refund.New(&stripe.RefundParams{
 		PaymentIntent: stripe.String(order.StripePaymentID),
 	})
@@ -221,7 +219,7 @@ func (h *OrderHandler) RefundOrder(w http.ResponseWriter, r *http.Request) {
 
 	audit.OrderRefunded(userID, order.ID, order.Total, rf.ID)
 
-	utils.RespondSuccess(w, http.StatusOK, map[string]interface{}{
+	utils.RespondSuccess(w, http.StatusOK, map[string]any{
 		"refund_id": rf.ID,
 		"status":    "refunded",
 	})
@@ -287,7 +285,7 @@ func (h *OrderHandler) UpdateTracking(w http.ResponseWriter, r *http.Request) {
 
 	audit.OrderShipped(order.UserID, order.ID, req.Carrier, req.TrackingNumber)
 
-	utils.RespondSuccess(w, http.StatusOK, map[string]interface{}{
+	utils.RespondSuccess(w, http.StatusOK, map[string]any{
 		"order_id":        order.ID,
 		"carrier":         req.Carrier,
 		"tracking_number": req.TrackingNumber,

api/handlers/orders_test.go

@@ -60,7 +60,7 @@ func contextWithRoute(ctx context.Context, routeCtx *chi.Context) context.Contex
 func TestCreateRefundRequestRequiresMessageForOther(t *testing.T) {
 	user := setupOrderTestDB(t)
 
-	handler := NewOrderHandler("", "", "", "")
+	handler := NewOrderHandler("", "", "")
 	body := []byte(`{"reason":"Other","message":"   "}`)
 	req := orderRequest("POST", "/api/v1/orders/1/refund-request", body, user.ID, "1")
 	w := httptest.NewRecorder()
@@ -100,7 +100,7 @@ func TestCreateRefundRequestRejectsInvalidOrderState(t *testing.T) {
 		t.Fatalf("failed to create order: %v", err)
 	}
 
-	handler := NewOrderHandler("", "", "", "")
+	handler := NewOrderHandler("", "", "")
 	body := []byte(`{"reason":"Quality issue","message":""}`)
 	req := orderRequest("POST", "/api/v1/orders/1/refund-request", body, user.ID, fmt.Sprintf("%d", order.ID))
 	w := httptest.NewRecorder()
@@ -142,7 +142,7 @@ func TestCreateRefundRequestEnforcesCooldown(t *testing.T) {
 		t.Fatalf("failed to create order: %v", err)
 	}
 
-	handler := NewOrderHandler("", "", "", "")
+	handler := NewOrderHandler("", "", "")
 	body := []byte(`{"reason":"Quality issue","message":""}`)
 	req := orderRequest("POST", "/api/v1/orders/1/refund-request", body, user.ID, fmt.Sprintf("%d", order.ID))
 	w := httptest.NewRecorder()

api/handlers/products.go

@@ -30,7 +30,7 @@ func (h *ProductHandler) GetProducts(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	utils.RespondSuccess(w, http.StatusOK, map[string]interface{}{
+	utils.RespondSuccess(w, http.StatusOK, map[string]any{
 		"products": products,
 	})
 }
@@ -53,7 +53,7 @@ func (h *ProductHandler) GetProduct(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	utils.RespondSuccess(w, http.StatusOK, map[string]interface{}{
+	utils.RespondSuccess(w, http.StatusOK, map[string]any{
 		"product": product,
 	})
 }

api/handlers/reconcile.go

@@ -5,6 +5,7 @@ import (
 	"log/slog"
 	"time"
 
+	"terminalShop/pkg/audit"
 	"terminalShop/pkg/database"
 	"terminalShop/pkg/models"
 	"terminalShop/pkg/notify"
@@ -14,14 +15,18 @@ import (
 	"gorm.io/gorm"
 )
 
+// paymentIntentGetFn lets tests stub the Stripe Get call without spinning
+// up an httptest backend. Production callers go straight through to the
+// real paymentintent.Get.
+var paymentIntentGetFn = paymentintent.Get
+
 func reconcileLog() *slog.Logger { return slog.With("component", "reconcile") }
 
 // ReconcileOrders finds pending orders with no Stripe ID older than 10 minutes
 // and checks whether Stripe has a succeeded PaymentIntent for them. This fixes
 // the case where the server crashed after charging but before the DB transaction
 // completed.
-func ReconcileOrders(stripeKey string) {
-	stripe.Key = stripeKey
+func ReconcileOrders() {
 	db := database.GetDB()
 
 	var orders []models.Order
@@ -49,7 +54,7 @@ func ReconcileOrders(stripeKey string) {
 				"order_id", order.ID, "pi", pi.ID)
 
 			txErr := db.Transaction(func(tx *gorm.DB) error {
-				if err := tx.Model(&order).Updates(map[string]interface{}{
+				if err := tx.Model(&order).Updates(map[string]any{
 					"status":            models.OrderStatusPaid,
 					"stripe_payment_id": pi.ID,
 				}).Error; err != nil {
@@ -62,7 +67,7 @@ func ReconcileOrders(stripeKey string) {
 				if err := tx.Where("cart_id = ?", cart.ID).Delete(&models.CartItem{}).Error; err != nil {
 					return err
 				}
-				return tx.Model(&cart).Updates(map[string]interface{}{
+				return tx.Model(&cart).Updates(map[string]any{
 					"address_id": nil,
 					"card_id":    nil,
 				}).Error
@@ -77,11 +82,103 @@ func ReconcileOrders(stripeKey string) {
 	}
 }
 
+// ReconcileStale3DSOrders flips requires_action orders that have been
+// awaiting the customer's 3DS challenge longer than threshold to failed,
+// after re-checking the PaymentIntent with Stripe so a late
+// payment_intent.succeeded webhook is respected. Deliberately separate
+// from ReconcileOrders: the empty-PI predicate there is load-bearing for
+// the crash-mid-create case (see sca-psd2-compliance.md caveat #20).
+// stripe.Key is wired once at startup in api/main.go.
+func ReconcileStale3DSOrders(threshold time.Duration) {
+	db := database.GetDB()
+
+	var orders []models.Order
+	// Predicate keys off updated_at, not created_at: respondRequiresAction
+	// and RetryAuth both bump updated_at via GORM auto-stamping, so every
+	// customer-driven retry extends the grace window. Intentional - sweeping
+	// a row the customer just re-armed would race the new challenge.
+	cutoff := time.Now().Add(-threshold)
+	if err := db.Where("status = ? AND updated_at < ?",
+		models.OrderStatusRequiresAction, cutoff).Find(&orders).Error; err != nil {
+		reconcileLog().Error("stale 3ds scan failed", "error", err)
+		return
+	}
+	if len(orders) == 0 {
+		return
+	}
+
+	reconcileLog().Info("checking stale requires_action orders", "count", len(orders))
+
+	for i := range orders {
+		order := &orders[i]
+		if order.StripePaymentID == "" {
+			// respondRequiresAction writes stripe_payment_id and status in
+			// one UPDATE so this should be unreachable; guard anyway so a
+			// future regression noisily logs instead of 4xx'ing Stripe.
+			reconcileLog().Warn("requires_action row missing PI id; skipping", "order_id", order.ID)
+			continue
+		}
+		actual, err := paymentIntentGetFn(order.StripePaymentID, nil)
+		if err != nil {
+			reconcileLog().Error("stripe get failed",
+				"order_id", order.ID, "pi", order.StripePaymentID, "error", err)
+			continue
+		}
+		switch actual.Status {
+		case stripe.PaymentIntentStatusSucceeded:
+			// Stripe says paid but our row still says requires_action, the
+			// payment_intent.succeeded webhook has not landed yet (or was
+			//  dropped). Defer to handlePaymentIntentsucceeded; it owns the
+			// paid transition + cart cleanup atomically. The next sweep
+			// tick re-checks and surfaces the dropped webhook if it persists
+			reconcileLog().Warn("stripe reports succeeded for requires_action row; deferring to webhook",
+				"order_id", order.ID, "pi", order.StripePaymentID)
+		case stripe.PaymentIntentStatusProcessing,
+			stripe.PaymentIntentStatusRequiresCapture:
+			reconcileLog().Info("payment intent still transitioning; skipping",
+				"order_id", order.ID, "pi", order.StripePaymentID, "stripe_status", string(actual.Status))
+		case stripe.PaymentIntentStatusRequiresAction,
+			stripe.PaymentIntentStatusRequiresPaymentMethod,
+			stripe.PaymentIntentStatusRequiresConfirmation,
+			stripe.PaymentIntentStatusCanceled:
+			flipStale3DSToFailed(db, order, string(actual.Status))
+		default:
+			reconcileLog().Warn("unrecognized stripe status; skipping",
+				"order_id", order.ID, "pi", order.StripePaymentID, "stripe_status", string(actual.Status))
+		}
+	}
+}
+
+// flipStale3DSToFailed transitions a single stale requires_action row
+// to failed. The UPDATE is conditional on status = requires_action so a
+// payment_intent.succeeded webhook that landed between the stripe get and
+// this write (caveat #20 race) wins and we silently no-op
+func flipStale3DSToFailed(db *gorm.DB, order *models.Order, stripeStatus string) {
+	// Map form so the single-field UPDATE is explicit at the call site.
+	// GORM still auto-stamps updated_at; the row exits the sweep predicate
+	// naturally on the next tick because status no longer matches anyway.
+	res := db.Model(&models.Order{}).
+		Where("id = ? AND status = ?", order.ID, models.OrderStatusRequiresAction).
+		Updates(map[string]any{"status": models.OrderStatusFailed})
+	if res.Error != nil {
+		reconcileLog().Error("flip stale 3ds failed", "order_id", order.ID, "error", res.Error)
+		return
+	}
+	if res.RowsAffected == 0 {
+		reconcileLog().Info("stale 3ds row already transitioned; sweep no-op",
+			"order_id", order.ID)
+		return
+	}
+	audit.Order3DSAbandoned(order.UserID, order.ID, order.StripePaymentID)
+	reconcileLog().Info("3ds abandoned order flipped to failed",
+		"order_id", order.ID, "pi", order.StripePaymentID, "stripe_status", stripeStatus)
+}
+
 // ReconcileExpiredCards removes saved cards whose retention deadline elapsed.
 // Read paths filter out expired rows so users never see them; this job drives
 // the Stripe detach + audit + physical row delete out of band so request
 // handlers never block on Stripe API calls during a card sweep.
-func ReconcileExpiredCards(stripeKey string) {
+func ReconcileExpiredCards() {
 	db := database.GetDB()
 
 	var cards []models.Card
@@ -98,7 +195,7 @@ func ReconcileExpiredCards(stripeKey string) {
 
 	reconcileLog().Info("expiring inactive saved cards", "count", len(cards))
 	for i := range cards {
-		if err := expireStoredCard(db, &cards[i], stripeKey); err != nil {
+		if err := expireStoredCard(db, &cards[i]); err != nil {
 			reconcileLog().Error("expire card failed", "card_id", cards[i].ID, "error", err)
 		}
 	}

api/handlers/reconcile_test.go

@@ -0,0 +1,429 @@
+package handlers
+
+import (
+	"fmt"
+	"os"
+	"testing"
+	"time"
+
+	"github.com/stripe/stripe-go/v78"
+
+	"terminalShop/pkg/audit"
+	"terminalShop/pkg/database"
+	"terminalShop/pkg/models"
+)
+
+// TestReconcileStale3DSOrders_FlipsAbandonedToFailed verifies the predicate
+// and Stripe-Get branching: a row past the threshold whose PaymentIntent
+// Stripe still reports as requires_payment_method (the customer never
+// completed the challenge) transitions to failed and emits the new
+// order_3ds_abandoned audit row.
+func TestReconcileStale3DSOrders_FlipsAbandonedToFailed(t *testing.T) {
+	testDB, user := setupCartTestDB(t)
+	defer func() { _ = os.Remove(testDB) }()
+	defer database.ResetForTesting()
+
+	db := database.GetDB()
+	audit.SetDB(db)
+	defer audit.SetDB(nil)
+
+	order := seedRequiresActionOrder(t, user.ID, "pi_stale_abandoned",
+		time.Now().Add(-1*time.Hour))
+
+	orig := paymentIntentGetFn
+	defer func() { paymentIntentGetFn = orig }()
+	paymentIntentGetFn = func(id string, _ *stripe.PaymentIntentParams) (*stripe.PaymentIntent, error) {
+		return &stripe.PaymentIntent{
+			ID:     id,
+			Status: stripe.PaymentIntentStatusRequiresPaymentMethod,
+		}, nil
+	}
+
+	ReconcileStale3DSOrders(30 * time.Minute)
+
+	var reloaded models.Order
+	if err := db.First(&reloaded, order.ID).Error; err != nil {
+		t.Fatalf("reload order: %v", err)
+	}
+	if reloaded.Status != models.OrderStatusFailed {
+		t.Fatalf("status: want %q, got %q", models.OrderStatusFailed, reloaded.Status)
+	}
+
+	var events []models.OrderEvent
+	if err := db.Where("order_id = ? AND type = ?",
+		order.ID, audit.EventOrder3DSAbandoned).Find(&events).Error; err != nil {
+		t.Fatalf("list events: %v", err)
+	}
+	if len(events) != 1 {
+		t.Fatalf("want 1 order_3ds_abandoned audit row, got %d", len(events))
+	}
+}
+
+// TestReconcileStale3DSOrders_SkipsRecent verifies the threshold predicate
+// excludes rows still within the grace window. A fresh requires_action row
+// must not even reach the Stripe Get call.
+func TestReconcileStale3DSOrders_SkipsRecent(t *testing.T) {
+	testDB, user := setupCartTestDB(t)
+	defer func() { _ = os.Remove(testDB) }()
+	defer database.ResetForTesting()
+
+	db := database.GetDB()
+	audit.SetDB(db)
+	defer audit.SetDB(nil)
+
+	order := seedRequiresActionOrder(t, user.ID, "pi_fresh_3ds",
+		time.Now().Add(-5*time.Minute))
+
+	called := false
+	orig := paymentIntentGetFn
+	defer func() { paymentIntentGetFn = orig }()
+	paymentIntentGetFn = func(id string, _ *stripe.PaymentIntentParams) (*stripe.PaymentIntent, error) {
+		called = true
+		return &stripe.PaymentIntent{
+			ID:     id,
+			Status: stripe.PaymentIntentStatusRequiresPaymentMethod,
+		}, nil
+	}
+
+	ReconcileStale3DSOrders(30 * time.Minute)
+
+	if called {
+		t.Fatalf("stripe Get called for in-window row")
+	}
+	var reloaded models.Order
+	if err := db.First(&reloaded, order.ID).Error; err != nil {
+		t.Fatalf("reload: %v", err)
+	}
+	if reloaded.Status != models.OrderStatusRequiresAction {
+		t.Fatalf("status changed unexpectedly: %q", reloaded.Status)
+	}
+}
+
+// TestReconcileStale3DSOrders_SkipsWhenStripeSaysSucceeded covers the
+// webhook-race guard from caveat #20. If Stripe-side already says succeeded,
+// the sweep must defer to handlePaymentIntentSucceeded rather than overwrite
+// the authoritative end state.
+func TestReconcileStale3DSOrders_SkipsWhenStripeSaysSucceeded(t *testing.T) {
+	testDB, user := setupCartTestDB(t)
+	defer func() { _ = os.Remove(testDB) }()
+	defer database.ResetForTesting()
+
+	db := database.GetDB()
+	audit.SetDB(db)
+	defer audit.SetDB(nil)
+
+	order := seedRequiresActionOrder(t, user.ID, "pi_succeeded_late_webhook",
+		time.Now().Add(-1*time.Hour))
+
+	orig := paymentIntentGetFn
+	defer func() { paymentIntentGetFn = orig }()
+	paymentIntentGetFn = func(id string, _ *stripe.PaymentIntentParams) (*stripe.PaymentIntent, error) {
+		return &stripe.PaymentIntent{
+			ID:     id,
+			Status: stripe.PaymentIntentStatusSucceeded,
+		}, nil
+	}
+
+	ReconcileStale3DSOrders(30 * time.Minute)
+
+	var reloaded models.Order
+	if err := db.First(&reloaded, order.ID).Error; err != nil {
+		t.Fatalf("reload: %v", err)
+	}
+	if reloaded.Status != models.OrderStatusRequiresAction {
+		t.Fatalf("must defer to webhook on succeeded; got %q", reloaded.Status)
+	}
+}
+
+// TestReconcileStale3DSOrders_GuardsAgainstWebhookRace covers the conditional
+// UPDATE. If the row flipped to paid between the Stripe Get and the flip,
+// the WHERE status = requires_action clause prevents clobber.
+func TestReconcileStale3DSOrders_GuardsAgainstWebhookRace(t *testing.T) {
+	testDB, user := setupCartTestDB(t)
+	defer func() { _ = os.Remove(testDB) }()
+	defer database.ResetForTesting()
+
+	db := database.GetDB()
+	audit.SetDB(db)
+	defer audit.SetDB(nil)
+
+	order := seedRequiresActionOrder(t, user.ID, "pi_race_paid",
+		time.Now().Add(-1*time.Hour))
+
+	orig := paymentIntentGetFn
+	defer func() { paymentIntentGetFn = orig }()
+	paymentIntentGetFn = func(id string, _ *stripe.PaymentIntentParams) (*stripe.PaymentIntent, error) {
+		db.Model(&models.Order{}).Where("id = ?", order.ID).
+			Update("status", models.OrderStatusPaid)
+		return &stripe.PaymentIntent{
+			ID:     id,
+			Status: stripe.PaymentIntentStatusRequiresPaymentMethod,
+		}, nil
+	}
+
+	ReconcileStale3DSOrders(30 * time.Minute)
+
+	var reloaded models.Order
+	if err := db.First(&reloaded, order.ID).Error; err != nil {
+		t.Fatalf("reload: %v", err)
+	}
+	if reloaded.Status != models.OrderStatusPaid {
+		t.Fatalf("conditional update must preserve paid; got %q", reloaded.Status)
+	}
+}
+
+// TestReconcileStale3DSOrders_FlipsCanceledPI covers the canceled-PI branch:
+// Stripe-terminal-canceled maps to OrderStatusFailed (matches RetryAuth's
+// existing precedent — see api/handlers/cart.go RetryAuth canceled branch).
+func TestReconcileStale3DSOrders_FlipsCanceledPI(t *testing.T) {
+	testDB, user := setupCartTestDB(t)
+	defer func() { _ = os.Remove(testDB) }()
+	defer database.ResetForTesting()
+
+	db := database.GetDB()
+	audit.SetDB(db)
+	defer audit.SetDB(nil)
+
+	order := seedRequiresActionOrder(t, user.ID, "pi_canceled_stale",
+		time.Now().Add(-1*time.Hour))
+
+	orig := paymentIntentGetFn
+	defer func() { paymentIntentGetFn = orig }()
+	paymentIntentGetFn = func(id string, _ *stripe.PaymentIntentParams) (*stripe.PaymentIntent, error) {
+		return &stripe.PaymentIntent{
+			ID:     id,
+			Status: stripe.PaymentIntentStatusCanceled,
+		}, nil
+	}
+
+	ReconcileStale3DSOrders(30 * time.Minute)
+
+	var reloaded models.Order
+	if err := db.First(&reloaded, order.ID).Error; err != nil {
+		t.Fatalf("reload: %v", err)
+	}
+	if reloaded.Status != models.OrderStatusFailed {
+		t.Fatalf("canceled PI must flip to failed; got %q", reloaded.Status)
+	}
+}
+
+// TestReconcileStale3DSOrders_DoesNotConsumeRetryCap regression-tests the
+// caveat #17 decoupling: the new sweep emits EventOrder3DSAbandoned, never
+// EventOrderRequiresAction, so a swept-then-stuck order does not silently
+// shrink the retry ceiling for any future user-driven retry attempts.
+func TestReconcileStale3DSOrders_DoesNotConsumeRetryCap(t *testing.T) {
+	testDB, user := setupCartTestDB(t)
+	defer func() { _ = os.Remove(testDB) }()
+	defer database.ResetForTesting()
+
+	db := database.GetDB()
+	audit.SetDB(db)
+	defer audit.SetDB(nil)
+
+	order := seedRequiresActionOrder(t, user.ID, "pi_decoupled_cap",
+		time.Now().Add(-1*time.Hour))
+
+	orig := paymentIntentGetFn
+	defer func() { paymentIntentGetFn = orig }()
+	paymentIntentGetFn = func(id string, _ *stripe.PaymentIntentParams) (*stripe.PaymentIntent, error) {
+		return &stripe.PaymentIntent{
+			ID:     id,
+			Status: stripe.PaymentIntentStatusRequiresPaymentMethod,
+		}, nil
+	}
+
+	ReconcileStale3DSOrders(30 * time.Minute)
+
+	var retryCount int64
+	if err := db.Model(&models.OrderEvent{}).
+		Where("order_id = ? AND type = ?", order.ID, audit.EventOrderRequiresAction).
+		Count(&retryCount).Error; err != nil {
+		t.Fatalf("count retry events: %v", err)
+	}
+	if retryCount != 0 {
+		t.Fatalf("sweep must not emit EventOrderRequiresAction; got %d", retryCount)
+	}
+}
+
+// TestReconcileStale3DSOrders_SkipsTransitioningStatuses covers the
+// processing and requires_capture branches: Stripe still owns the PI's
+// next move, so the sweep must not flip even past the threshold.
+func TestReconcileStale3DSOrders_SkipsTransitioningStatuses(t *testing.T) {
+	cases := []struct {
+		name   string
+		status stripe.PaymentIntentStatus
+	}{
+		{"processing", stripe.PaymentIntentStatusProcessing},
+		{"requires_capture", stripe.PaymentIntentStatusRequiresCapture},
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			testDB, user := setupCartTestDB(t)
+			defer func() { _ = os.Remove(testDB) }()
+			defer database.ResetForTesting()
+
+			db := database.GetDB()
+			audit.SetDB(db)
+			defer audit.SetDB(nil)
+
+			order := seedRequiresActionOrder(t, user.ID,
+				"pi_transitioning_"+tc.name, time.Now().Add(-1*time.Hour))
+
+			orig := paymentIntentGetFn
+			defer func() { paymentIntentGetFn = orig }()
+			paymentIntentGetFn = func(id string, _ *stripe.PaymentIntentParams) (*stripe.PaymentIntent, error) {
+				return &stripe.PaymentIntent{ID: id, Status: tc.status}, nil
+			}
+
+			ReconcileStale3DSOrders(30 * time.Minute)
+
+			var reloaded models.Order
+			if err := db.First(&reloaded, order.ID).Error; err != nil {
+				t.Fatalf("reload: %v", err)
+			}
+			if reloaded.Status != models.OrderStatusRequiresAction {
+				t.Fatalf("%s must stay requires_action; got %q", tc.name, reloaded.Status)
+			}
+		})
+	}
+}
+
+// TestReconcileStale3DSOrders_SkipsUnknownStatus covers the switch's default
+// arm: an unrecognized Stripe status logs and skips rather than guessing a
+// transition. Defends against new PI statuses appearing in future SDKs.
+func TestReconcileStale3DSOrders_SkipsUnknownStatus(t *testing.T) {
+	testDB, user := setupCartTestDB(t)
+	defer func() { _ = os.Remove(testDB) }()
+	defer database.ResetForTesting()
+
+	db := database.GetDB()
+	audit.SetDB(db)
+	defer audit.SetDB(nil)
+
+	order := seedRequiresActionOrder(t, user.ID, "pi_unknown_status",
+		time.Now().Add(-1*time.Hour))
+
+	orig := paymentIntentGetFn
+	defer func() { paymentIntentGetFn = orig }()
+	paymentIntentGetFn = func(id string, _ *stripe.PaymentIntentParams) (*stripe.PaymentIntent, error) {
+		return &stripe.PaymentIntent{
+			ID:     id,
+			Status: stripe.PaymentIntentStatus("some_new_future_status"),
+		}, nil
+	}
+
+	ReconcileStale3DSOrders(30 * time.Minute)
+
+	var reloaded models.Order
+	if err := db.First(&reloaded, order.ID).Error; err != nil {
+		t.Fatalf("reload: %v", err)
+	}
+	if reloaded.Status != models.OrderStatusRequiresAction {
+		t.Fatalf("unknown status must not flip; got %q", reloaded.Status)
+	}
+}
+
+// TestReconcileStale3DSOrders_SkipsOnStripeError verifies a Stripe Get
+// failure logs and leaves the row alone. Transient network errors must not
+// look like an abandoned 3DS.
+func TestReconcileStale3DSOrders_SkipsOnStripeError(t *testing.T) {
+	testDB, user := setupCartTestDB(t)
+	defer func() { _ = os.Remove(testDB) }()
+	defer database.ResetForTesting()
+
+	db := database.GetDB()
+	audit.SetDB(db)
+	defer audit.SetDB(nil)
+
+	order := seedRequiresActionOrder(t, user.ID, "pi_stripe_error",
+		time.Now().Add(-1*time.Hour))
+
+	orig := paymentIntentGetFn
+	defer func() { paymentIntentGetFn = orig }()
+	paymentIntentGetFn = func(_ string, _ *stripe.PaymentIntentParams) (*stripe.PaymentIntent, error) {
+		return nil, fmt.Errorf("simulated stripe outage")
+	}
+
+	ReconcileStale3DSOrders(30 * time.Minute)
+
+	var reloaded models.Order
+	if err := db.First(&reloaded, order.ID).Error; err != nil {
+		t.Fatalf("reload: %v", err)
+	}
+	if reloaded.Status != models.OrderStatusRequiresAction {
+		t.Fatalf("stripe error must not flip; got %q", reloaded.Status)
+	}
+}
+
+// TestReconcileStale3DSOrders_SkipsEmptyPaymentIntentID guards the
+// defensive empty-PI short-circuit: even past the threshold, a row missing
+// stripe_payment_id must not reach paymentintent.Get (which would 4xx).
+func TestReconcileStale3DSOrders_SkipsEmptyPaymentIntentID(t *testing.T) {
+	testDB, user := setupCartTestDB(t)
+	defer func() { _ = os.Remove(testDB) }()
+	defer database.ResetForTesting()
+
+	db := database.GetDB()
+	audit.SetDB(db)
+	defer audit.SetDB(nil)
+
+	order := seedRequiresActionOrder(t, user.ID, "pi_will_be_blanked",
+		time.Now().Add(-1*time.Hour))
+	if err := db.Model(&order).UpdateColumn("stripe_payment_id", "").Error; err != nil {
+		t.Fatalf("blank PI id: %v", err)
+	}
+
+	called := false
+	orig := paymentIntentGetFn
+	defer func() { paymentIntentGetFn = orig }()
+	paymentIntentGetFn = func(_ string, _ *stripe.PaymentIntentParams) (*stripe.PaymentIntent, error) {
+		called = true
+		return &stripe.PaymentIntent{Status: stripe.PaymentIntentStatusRequiresPaymentMethod}, nil
+	}
+
+	ReconcileStale3DSOrders(30 * time.Minute)
+
+	if called {
+		t.Fatalf("stripe Get called for empty-PI row")
+	}
+	var reloaded models.Order
+	if err := db.First(&reloaded, order.ID).Error; err != nil {
+		t.Fatalf("reload: %v", err)
+	}
+	if reloaded.Status != models.OrderStatusRequiresAction {
+		t.Fatalf("empty-PI guard must leave status alone; got %q", reloaded.Status)
+	}
+}
+
+// seedRequiresActionOrder inserts a card + order pair in the requires_action
+// state. updatedAt is forced via UpdateColumn so GORM's auto-stamping of
+// UpdatedAt on Create does not bump the row out of the sweep predicate.
+func seedRequiresActionOrder(t *testing.T, userID uint, piID string, updatedAt time.Time) models.Order {
+	t.Helper()
+	db := database.GetDB()
+	card := models.Card{
+		UserID:          userID,
+		StripePaymentID: "pm_test_" + piID,
+		Last4:           "4242", Brand: "Visa",
+		ExpMonth: 12, ExpYear: 2030,
+	}
+	if err := db.Create(&card).Error; err != nil {
+		t.Fatalf("seed card: %v", err)
+	}
+	order := models.Order{
+		UserID: userID, CardID: card.ID,
+		StripePaymentID: piID,
+		Status:          models.OrderStatusRequiresAction,
+		Subtotal:        500, Total: 500,
+		ShippingName: "Test", ShippingStreet: "1 Main St",
+		ShippingCity: "PDX", ShippingState: "OR",
+		ShippingZip: "97201", ShippingCountry: "US",
+	}
+	if err := db.Create(&order).Error; err != nil {
+		t.Fatalf("seed order: %v", err)
+	}
+	if err := db.Model(&order).UpdateColumn("updated_at", updatedAt).Error; err != nil {
+		t.Fatalf("backdate updated_at: %v", err)
+	}
+	return order
+}

api/handlers/view.go

@@ -54,7 +54,7 @@ func (h *ViewHandler) GetViewInit(w http.ResponseWriter, r *http.Request) {
 		db.Where("cart_id = ? AND quantity > 0", cart.ID).Preload("Coffee").Find(&cartItems)
 	}
 
-	utils.RespondSuccess(w, http.StatusOK, map[string]interface{}{
+	utils.RespondSuccess(w, http.StatusOK, map[string]any{
 		"user":      user.ToPublic(),
 		"products":  products,
 		"cart":      cartItems,

api/handlers/webhook.go

@@ -28,13 +28,13 @@ func webhookLog() *slog.Logger { return slog.With("component", "webhook") }
 // WebhookHandler handles inbound Stripe webhook events.
 type WebhookHandler struct {
 	webhookSecret string
-	stripeKey     string
 	shippoSecret  string
 }
 
-// NewWebhookHandler creates a new webhook handler.
-func NewWebhookHandler(webhookSecret, stripeKey, shippoSecret string) *WebhookHandler {
-	return &WebhookHandler{webhookSecret: webhookSecret, stripeKey: stripeKey, shippoSecret: shippoSecret}
+// NewWebhookHandler creates a new webhook handler. Stripe credentials are
+// wired once at startup via stripe.Key in api/main.go.
+func NewWebhookHandler(webhookSecret, shippoSecret string) *WebhookHandler {
+	return &WebhookHandler{webhookSecret: webhookSecret, shippoSecret: shippoSecret}
 }
 
 // HandleStripe validates the Stripe signature and routes the event.
@@ -125,7 +125,7 @@ func (h *WebhookHandler) handlePaymentIntentSucceeded(ctx context.Context, event
 	}
 
 	txErr := db.Transaction(func(tx *gorm.DB) error {
-		if err := tx.Model(&order).Updates(map[string]interface{}{
+		if err := tx.Model(&order).Updates(map[string]any{
 			"status":            models.OrderStatusPaid,
 			"stripe_payment_id": pi.ID,
 		}).Error; err != nil {
@@ -139,7 +139,7 @@ func (h *WebhookHandler) handlePaymentIntentSucceeded(ctx context.Context, event
 		if err := tx.Where("cart_id = ?", cart.ID).Delete(&models.CartItem{}).Error; err != nil {
 			return fmt.Errorf("failed to delete cart item: %w", err)
 		}
-		return tx.Model(&cart).Updates(map[string]interface{}{
+		return tx.Model(&cart).Updates(map[string]any{
 			"address_id": nil,
 			"card_id":    nil,
 		}).Error
@@ -184,7 +184,7 @@ func (h *WebhookHandler) handlePaymentIntentFailed(ctx context.Context, event st
 	}
 
 	db := database.GetDB().WithContext(ctx)
-	if err := db.Model(&models.Order{}).Where("id = ? AND status = ?", orderIDStr, models.OrderStatusPending).
+	if err := db.Model(&models.Order{}).Where("id = ? AND status IN (?, ?)", orderIDStr, models.OrderStatusPending, models.OrderStatusRequiresAction).
 		Update("status", models.OrderStatusFailed).Error; err != nil {
 		webhookLog().Error("failed to mark order failed", "order_id", orderIDStr, "error", err)
 	}
@@ -212,8 +212,6 @@ func (h *WebhookHandler) handleCheckoutSessionCompleted(ctx context.Context, eve
 		return
 	}
 
-	stripe.Key = h.stripeKey
-
 	si, err := setupintent.Get(sess.SetupIntent.ID, nil)
 	if err != nil {
 		webhookLog().Error("failed to get setup intent", "setup_intent", sess.SetupIntent.ID, "error", err)

api/handlers/webhook_test.go

@@ -0,0 +1,224 @@
+package handlers
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"os"
+	"testing"
+
+	"github.com/stripe/stripe-go/v78"
+
+	"terminalShop/pkg/database"
+	"terminalShop/pkg/models"
+)
+
+// buildPaymentFailedEvent constructs a stripe.Event whose Data.Raw decodes to
+// a PaymentIntent referencing the given order via metadata. errCode is set on
+// last_payment_error to drive the authentication_required short-circuit
+// branch in handlePaymentIntentFailed (pass "" to omit the error block).
+func buildPaymentFailedEvent(t *testing.T, piID string, orderID uint, errCode string) stripe.Event {
+	t.Helper()
+	pi := map[string]any{
+		"id":       piID,
+		"metadata": map[string]string{"order_id": fmt.Sprintf("%d", orderID)},
+	}
+	if errCode != "" {
+		pi["last_payment_error"] = map[string]any{"code": errCode}
+	}
+	raw, err := json.Marshal(pi)
+	if err != nil {
+		t.Fatalf("marshal pi: %v", err)
+	}
+	return stripe.Event{
+		Type: "payment_intent.payment_failed",
+		Data: &stripe.EventData{Raw: raw},
+	}
+}
+
+func seedOrderForWebhook(t *testing.T, userID uint, status models.OrderStatus, piID string) models.Order {
+	t.Helper()
+	db := database.GetDB()
+	card := models.Card{
+		UserID:          userID,
+		StripePaymentID: fmt.Sprintf("pm_test_%s", piID),
+		Last4:           "4242", Brand: "Visa", ExpMonth: 12, ExpYear: 2030,
+	}
+	if err := db.Create(&card).Error; err != nil {
+		t.Fatalf("seed card: %v", err)
+	}
+	order := models.Order{
+		UserID: userID, CardID: card.ID,
+		StripePaymentID: piID,
+		Status:          status,
+		Subtotal:        500, Total: 500,
+		ShippingName: "Test", ShippingStreet: "1 Main St",
+		ShippingCity: "PDX", ShippingState: "OR",
+		ShippingZip: "97201", ShippingCountry: "US",
+	}
+	if err := db.Create(&order).Error; err != nil {
+		t.Fatalf("seed order: %v", err)
+	}
+	return order
+}
+
+// TestHandlePaymentIntentFailed_RequiresActionFlipsToFailed verifies the
+// widened predicate (IN (pending, requires_action)) catches a row in the new
+// requires_action state. Without this case, a card_declined webhook arriving
+// after respondRequiresAction wrote requires_action would leave the row
+// stuck forever.
+func TestHandlePaymentIntentFailed_RequiresActionFlipsToFailed(t *testing.T) {
+	testDB, user := setupCartTestDB(t)
+	defer func() { _ = os.Remove(testDB) }()
+	defer database.ResetForTesting()
+
+	order := seedOrderForWebhook(t, user.ID, models.OrderStatusRequiresAction, "pi_test_req_action_failed")
+
+	h := NewWebhookHandler("", "")
+	evt := buildPaymentFailedEvent(t, order.StripePaymentID, order.ID, "card_declined")
+	h.handlePaymentIntentFailed(context.Background(), evt)
+
+	db := database.GetDB()
+	var reloaded models.Order
+	if err := db.First(&reloaded, order.ID).Error; err != nil {
+		t.Fatalf("reload order: %v", err)
+	}
+	if reloaded.Status != models.OrderStatusFailed {
+		t.Fatalf("status: want %q, got %q", models.OrderStatusFailed, reloaded.Status)
+	}
+}
+
+// TestHandlePaymentIntentFailed_RequiresActionAuthRequiredShortCircuits
+// verifies the existing short-circuit (note #3 in sca-psd2-compliance.md)
+// still fires when the row is in requires_action and the error code is
+// authentication_required. Without the short-circuit, the recovery flow
+// would race the webhook and surface a momentarily-failed state to the TUI.
+func TestHandlePaymentIntentFailed_RequiresActionAuthRequiredShortCircuits(t *testing.T) {
+	testDB, user := setupCartTestDB(t)
+	defer func() { _ = os.Remove(testDB) }()
+	defer database.ResetForTesting()
+
+	order := seedOrderForWebhook(t, user.ID, models.OrderStatusRequiresAction, "pi_test_req_action_authreq")
+
+	h := NewWebhookHandler("", "")
+	evt := buildPaymentFailedEvent(t, order.StripePaymentID, order.ID, "authentication_required")
+	h.handlePaymentIntentFailed(context.Background(), evt)
+
+	db := database.GetDB()
+	var reloaded models.Order
+	if err := db.First(&reloaded, order.ID).Error; err != nil {
+		t.Fatalf("reload order: %v", err)
+	}
+	if reloaded.Status != models.OrderStatusRequiresAction {
+		t.Fatalf("auth_required must not flip requires_action; got %q", reloaded.Status)
+	}
+}
+
+// TestHandlePaymentIntentFailed_PendingStillFlips guards the pre-existing
+// pending -> failed transition against a regression where the widened
+// predicate accidentally dropped pending from the source set.
+func TestHandlePaymentIntentFailed_PendingStillFlips(t *testing.T) {
+	testDB, user := setupCartTestDB(t)
+	defer func() { _ = os.Remove(testDB) }()
+	defer database.ResetForTesting()
+
+	order := seedOrderForWebhook(t, user.ID, models.OrderStatusPending, "pi_test_pending_failed")
+
+	h := NewWebhookHandler("", "")
+	evt := buildPaymentFailedEvent(t, order.StripePaymentID, order.ID, "card_declined")
+	h.handlePaymentIntentFailed(context.Background(), evt)
+
+	db := database.GetDB()
+	var reloaded models.Order
+	if err := db.First(&reloaded, order.ID).Error; err != nil {
+		t.Fatalf("reload order: %v", err)
+	}
+	if reloaded.Status != models.OrderStatusFailed {
+		t.Fatalf("status: want %q, got %q", models.OrderStatusFailed, reloaded.Status)
+	}
+}
+
+// TestHandlePaymentIntentFailed_PaidNotTouched locks the upper boundary of
+// the predicate: a paid row must NEVER be flipped to failed by a stale
+// payment_failed webhook. Without this guard, a future maintainer could
+// widen the IN clause to include paid (e.g. for some refund-retry flow)
+// and silently break idempotency.
+func TestHandlePaymentIntentFailed_PaidNotTouched(t *testing.T) {
+	testDB, user := setupCartTestDB(t)
+	defer func() { _ = os.Remove(testDB) }()
+	defer database.ResetForTesting()
+
+	order := seedOrderForWebhook(t, user.ID, models.OrderStatusPaid, "pi_test_paid_untouched")
+
+	h := NewWebhookHandler("", "")
+	evt := buildPaymentFailedEvent(t, order.StripePaymentID, order.ID, "card_declined")
+	h.handlePaymentIntentFailed(context.Background(), evt)
+
+	db := database.GetDB()
+	var reloaded models.Order
+	if err := db.First(&reloaded, order.ID).Error; err != nil {
+		t.Fatalf("reload order: %v", err)
+	}
+	if reloaded.Status != models.OrderStatusPaid {
+		t.Fatalf("paid order was modified by payment_failed webhook: got %q", reloaded.Status)
+	}
+}
+
+// TestHandlePaymentIntentFailed_MissingMetadataNoOp covers the no-order
+// short-circuit so the test file exercises every early-return branch in
+// handlePaymentIntentFailed touched by the predicate work.
+func TestHandlePaymentIntentFailed_MissingMetadataNoOp(t *testing.T) {
+	testDB, _ := setupCartTestDB(t)
+	defer func() { _ = os.Remove(testDB) }()
+	defer database.ResetForTesting()
+
+	pi := map[string]any{"id": "pi_test_no_meta"}
+	raw, err := json.Marshal(pi)
+	if err != nil {
+		t.Fatalf("marshal pi: %v", err)
+	}
+	evt := stripe.Event{
+		Type: "payment_intent.payment_failed",
+		Data: &stripe.EventData{Raw: raw},
+	}
+
+	h := NewWebhookHandler("", "")
+	h.handlePaymentIntentFailed(context.Background(), evt) // must not panic
+}
+
+func TestHandlePaymentIntentSucceeded_RequiresActionFlipsToPaid(t *testing.T) {
+	testDB, user := setupCartTestDB(t)
+	defer func() { _ = os.Remove(testDB) }()
+	defer database.ResetForTesting()
+
+	order := seedOrderForWebhook(t, user.ID, models.OrderStatusRequiresAction, "pi_test_req_action_paid")
+
+	pi := map[string]any{
+		"id":       order.StripePaymentID,
+		"amount":   order.Total,
+		"metadata": map[string]string{"order_id": fmt.Sprintf("%d", order.ID)},
+	}
+	raw, err := json.Marshal(pi)
+	if err != nil {
+		t.Fatalf("marshal pi: %v", err)
+	}
+	evt := stripe.Event{
+		Type: "payment_intent.succeeded",
+		Data: &stripe.EventData{Raw: raw},
+	}
+
+	h := NewWebhookHandler("", "")
+	h.handlePaymentIntentSucceeded(context.Background(), evt)
+
+	db := database.GetDB()
+	var reloaded models.Order
+	if err := db.First(&reloaded, order.ID).Error; err != nil {
+		t.Fatalf("reload order: %v", err)
+	}
+	if reloaded.Status != models.OrderStatusPaid {
+		t.Fatalf("status: want %q, got %q", models.OrderStatusPaid, reloaded.Status)
+	}
+	if reloaded.StripePaymentID != order.StripePaymentID {
+		t.Fatalf("stripe_payment_id: want %q, got %q", order.StripePaymentID, reloaded.StripePaymentID)
+	}
+}

api/main.go

@@ -19,6 +19,8 @@ import (
 	"terminalShop/pkg/database"
 	"terminalShop/pkg/observability"
 	"terminalShop/pkg/stripeclient"
+
+	"github.com/stripe/stripe-go/v78"
 )
 
 const version = "v0.1.0"
@@ -49,6 +51,12 @@ func main() {
 	}
 	audit.SetDB(db)
 
+	// wire the stripe SDK's package-level key once at startup so concurrent
+	// reconcilers and the request path don't race on stripe.Key writes.
+	// NOTE: assumes single-process — if you ever embed both the SSH and API
+	// binaries together, the last writer wins and one of them silently breaks.
+	stripe.Key = cfg.StripeSecretKey
+
 	// Seed database with initial data
 	if err := database.Seed(db); err != nil {
 		log.Fatalf("Failed to seed database: %v", err)
@@ -71,7 +79,7 @@ func main() {
 	jwtManager := auth.NewJWTManager(cfg.JWTSecret, 30*time.Minute)
 
 	// Setup routes
-	router := routes.SetupRoutes(version, cfg.StripeSecretKey, cfg.StripeWebhookSecret, jwtManager, cfg.AuthFingerprintKey, cfg.ShippoAPIKey, cfg.BringAPIUID, cfg.BringAPIKey, cfg.BringCustomerNumber, cfg.ShippoWebhookSecret, cfg.AppURL, cfg.SlackSigningSecret, cfg.AdminAPIKey, cfg.APIPort, cfg.MaxOrderCents)
+	router := routes.SetupRoutes(version, cfg.StripeWebhookSecret, jwtManager, cfg.AuthFingerprintKey, cfg.ShippoAPIKey, cfg.BringAPIUID, cfg.BringAPIKey, cfg.BringCustomerNumber, cfg.ShippoWebhookSecret, cfg.AppURL, cfg.SlackSigningSecret, cfg.AdminAPIKey, cfg.APIPort, cfg.MaxOrderCents)
 
 	// Create HTTP server
 	server := &http.Server{
@@ -106,7 +114,7 @@ func main() {
 		for {
 			select {
 			case <-ticker.C:
-				handlers.ReconcileOrders(cfg.StripeSecretKey)
+				handlers.ReconcileOrders()
 			case <-ctx.Done():
 				return
 			}
@@ -137,7 +145,21 @@ func main() {
 		for {
 			select {
 			case <-ticker.C:
-				handlers.ReconcileExpiredCards(cfg.StripeSecretKey)
+				handlers.ReconcileExpiredCards()
+			case <-ctx.Done():
+				return
+			}
+		}
+	}()
+
+	go func() {
+		ticker := time.NewTicker(15 * time.Minute)
+		defer ticker.Stop()
+		threshold := time.Duration(cfg.Abandoned3DSThresholdMinutes) * time.Minute
+		for {
+			select {
+			case <-ticker.C:
+				handlers.ReconcileStale3DSOrders(threshold)
 			case <-ctx.Done():
 				return
 			}

api/routes/routes.go

@@ -16,7 +16,6 @@ import (
 // SetupRoutes configures all API routes
 func SetupRoutes(
 	version string,
-	stripeSecretKey string,
 	stripeWebhookSecret string,
 	jwtManager *auth.JWTManager,
 	authFingerprintKey string,
@@ -47,12 +46,12 @@ func SetupRoutes(
 	healthHandler := handlers.NewHealthHandler(version)
 	productHandler := handlers.NewProductHandler()
 	authHandler := handlers.NewAuthHandler(jwtManager, authFingerprintKey)
-	cartHandler := handlers.NewCartHandler(stripeSecretKey, appURL, maxOrderCents)
-	cardHandler := handlers.NewCardHandler(stripeSecretKey, appURL)
-	orderHandler := handlers.NewOrderHandler(stripeSecretKey, bringAPIUID, bringAPIKey, bringCustomerNumber)
+	cartHandler := handlers.NewCartHandler(appURL, maxOrderCents)
+	cardHandler := handlers.NewCardHandler(appURL)
+	orderHandler := handlers.NewOrderHandler(bringAPIUID, bringAPIKey, bringCustomerNumber)
 	addressHandler := handlers.NewAddressHandler(shippoAPIKey, bringAPIUID, bringAPIKey)
 	viewHandler := handlers.NewViewHandler()
-	webhookHandler := handlers.NewWebhookHandler(stripeWebhookSecret, stripeSecretKey, shippoWebhookSecret)
+	webhookHandler := handlers.NewWebhookHandler(stripeWebhookSecret, shippoWebhookSecret)
 	slackHandler := handlers.NewSlackHandler(slackSigningSecret, adminAPIKey, apiPort, shippoWebhookSecret)
 
 	// Short payment redirect and success page — no auth required.

main.go

@@ -15,6 +15,7 @@ import (
 	"charm.land/wish/v2/bubbletea"
 	"charm.land/wish/v2/logging"
 	"github.com/charmbracelet/ssh"
+	"github.com/stripe/stripe-go/v78"
 
 	"terminalShop/pkg/auth"
 	"terminalShop/pkg/config"
@@ -31,7 +32,6 @@ func listenHost() string {
 var (
 	apiURL             string
 	authFingerprintKey string
-	stripePublicKey    string
 )
 
 func teaHandler(s ssh.Session) (tea.Model, []tea.ProgramOption) {
@@ -43,7 +43,7 @@ func teaHandler(s ssh.Session) (tea.Model, []tea.ProgramOption) {
 		pubKeyStr = auth.FormatSSHPublicKey(pubKey)
 	}
 
-	m := tui.NewModelWithAuth(fingerprint, pubKeyStr, apiURL, authFingerprintKey, stripePublicKey)
+	m := tui.NewModelWithAuth(fingerprint, pubKeyStr, apiURL, authFingerprintKey)
 	return m, nil
 }
 
@@ -57,7 +57,15 @@ func main() {
 	// Set API URL and auth key from config for TUI connections
 	apiURL = cfg.APIURL
 	authFingerprintKey = cfg.AuthFingerprintKey
-	stripePublicKey = cfg.StripePublicKey
+
+	// Wire the publishable key into stripe-go's package-level global once.
+	// TUI uses the legacy Tokens API (stripetoken.New) which accepts the
+	// publishable key; per-session writes would race across concurrent SSH
+	// sessions even though they'd all write the same value.
+	// NOTE: assumes single-process — if you ever embed both the SSH and API
+	// binaries together, the last writer wins and one of them silently breaks.
+	stripe.Key = cfg.StripePublicKey
+
 	log.Printf("TUI will connect to API at: %s", apiURL)
 
 	// Create SSH server

pkg/api/client.go

@@ -104,16 +104,16 @@ func (c *Client) RefreshToken(fingerprint, clientSecret string) (string, error)
 
 // APIResponse represents the standard API response format
 type APIResponse struct {
-	Success bool                   `json:"success"`
-	Data    map[string]interface{} `json:"data"`
-	Error   *APIError              `json:"error,omitempty"`
+	Success bool           `json:"success"`
+	Data    map[string]any `json:"data"`
+	Error   *APIError      `json:"error,omitempty"`
 }
 
 // APIError represents an error from the API
 type APIError struct {
-	Code    string                 `json:"code"`
-	Message string                 `json:"message"`
-	Details map[string]interface{} `json:"details,omitempty"`
+	Code    string         `json:"code"`
+	Message string         `json:"message"`
+	Details map[string]any `json:"details,omitempty"`
 }
 
 // ProductsResponse represents the products API response
@@ -339,7 +339,7 @@ func (c *Client) GetCart() (*CartData, error) {
 func (c *Client) SetCartItem(coffeeID uint, quantity int) (*CartData, error) {
 	url := fmt.Sprintf("%s/api/v1/cart/item", c.BaseURL)
 
-	body := map[string]interface{}{
+	body := map[string]any{
 		"coffee_id": coffeeID,
 		"quantity":  quantity,
 	}
@@ -379,7 +379,7 @@ func (c *Client) SetCartItem(coffeeID uint, quantity int) (*CartData, error) {
 func (c *Client) SetCartAddress(addressID uint) error {
 	url := fmt.Sprintf("%s/api/v1/cart/address", c.BaseURL)
 
-	body := map[string]interface{}{
+	body := map[string]any{
 		"address_id": addressID,
 	}
 	jsonData, err := json.Marshal(body)
@@ -418,7 +418,7 @@ func (c *Client) SetCartAddress(addressID uint) error {
 func (c *Client) SetCartCard(cardID uint) error {
 	url := fmt.Sprintf("%s/api/v1/cart/card", c.BaseURL)
 
-	body := map[string]interface{}{
+	body := map[string]any{
 		"card_id": cardID,
 	}
 	jsonData, err := json.Marshal(body)

pkg/audit/audit.go

@@ -14,10 +14,16 @@ import (
 )
 
 // EventOrderRequiresAction is the audit event-type string emitted whenever a
-// PaymentIntent is pushed into requires_action. explored so cart-flow handler
+// PaymentIntent is pushed into requires_action. Exposed so cart-flow handler
 // can count retry attempts without hardcoding the string literal.
 const EventOrderRequiresAction = "order_requires_action"
 
+// EventOrder3DSAbandoned is the audit event-type string emitted by the
+// abandoned-3DS sweep when it flips a stale requires_action row to failed.
+// Distinct from EventOrderRequiresAction (caveat #17) so the retry-cap count
+// stays decoupled from sweep activity
+const EventOrder3DSAbandoned = "order_3ds_abandoned"
+
 type eventType string
 
 const (
@@ -29,6 +35,7 @@ const (
 	eventOrderShipped           eventType = "order_shipped"
 	eventOrderFailed            eventType = "order_failed"
 	eventOrderRequiresAction    eventType = EventOrderRequiresAction
+	eventOrder3DSAbandoned      eventType = EventOrder3DSAbandoned
 	eventOrderRefunded          eventType = "order_refunded"
 	eventPaymentCritical        eventType = "payment_critical"
 	eventLabelPurchased         eventType = "label_purchased"
@@ -328,3 +335,17 @@ func OrderRequiresAction(userID, orderID uint, paymentIntentID string) {
 	slog.Info("audit", e.attrs()...)
 	persist(orderID, eventOrderRequiresAction, e)
 }
+
+// Order3DSAbandoned records the abandoned-3DS sweep flipping a stale
+// requires_action row to failed because Stripe still reports the underlying
+// PaymentIntent as outstanding past the sweep threshold.
+func Order3DSAbandoned(userID, orderID uint, paymentIntentID string) {
+	e := event{
+		Event:    eventOrder3DSAbandoned,
+		UserID:   userID,
+		OrderID:  orderID,
+		StripeID: paymentIntentID,
+	}
+	slog.Info("audit", e.attrs()...)
+	persist(orderID, eventOrder3DSAbandoned, e)
+}

pkg/auth/jwt.go

@@ -53,7 +53,7 @@ func (m *JWTManager) GenerateToken(userID uint, email, username string) (string,
 
 // ValidateToken validates a JWT token and returns the claims
 func (m *JWTManager) ValidateToken(tokenString string) (*Claims, error) {
-	token, err := jwt.ParseWithClaims(tokenString, &Claims{}, func(token *jwt.Token) (interface{}, error) {
+	token, err := jwt.ParseWithClaims(tokenString, &Claims{}, func(token *jwt.Token) (any, error) {
 		// Verify signing method
 		if _, ok := token.Method.(*jwt.SigningMethodHMAC); !ok {
 			return nil, fmt.Errorf("unexpected signing method: %v", token.Header["alg"])

pkg/config/config.go

@@ -3,6 +3,7 @@ package config
 import (
 	"errors"
 	"fmt"
+	"log/slog"
 	"net/url"
 	"os"
 	"strconv"
@@ -13,25 +14,26 @@ import (
 
 // Config holds all application configuration
 type Config struct {
-	APIPort             string
-	APIURL              string
-	AppURL              string
-	SSHPort             string
-	Environment         string
-	DatabaseURL         string
-	JWTSecret           string
-	StripeSecretKey     string
-	StripePublicKey     string
-	StripeWebhookSecret string
-	ShippoAPIKey        string
-	AuthFingerprintKey  string
-	BringAPIUID         string
-	BringAPIKey         string
-	BringCustomerNumber string
-	ShippoWebhookSecret string
-	SlackSigningSecret  string
-	AdminAPIKey         string
-	MaxOrderCents       int
+	APIPort                      string
+	APIURL                       string
+	AppURL                       string
+	SSHPort                      string
+	Environment                  string
+	DatabaseURL                  string
+	JWTSecret                    string
+	StripeSecretKey              string
+	StripePublicKey              string
+	StripeWebhookSecret          string
+	ShippoAPIKey                 string
+	AuthFingerprintKey           string
+	BringAPIUID                  string
+	BringAPIKey                  string
+	BringCustomerNumber          string
+	ShippoWebhookSecret          string
+	SlackSigningSecret           string
+	AdminAPIKey                  string
+	MaxOrderCents                int
+	Abandoned3DSThresholdMinutes int
 }
 
 // Load reads configuration from environment variables and validates required secrets.
@@ -50,25 +52,26 @@ func Load() (*Config, error) {
 	apiPort := getEnvOrDefault("API_PORT", "8080")
 	apiURL := getEnvOrDefault("API_URL", fmt.Sprintf("http://localhost:%s", apiPort))
 	cfg := &Config{
-		APIPort:             apiPort,
-		APIURL:              apiURL,
-		AppURL:              getEnvOrDefault("APP_URL", apiURL),
-		SSHPort:             getEnvOrDefault("SSH_PORT", "23457"),
-		Environment:         getEnvOrDefault("ENVIRONMENT", "development"),
-		DatabaseURL:         getEnvOrDefault("DATABASE_URL", "terminalshop.db"),
-		JWTSecret:           os.Getenv("JWT_SECRET"),
-		StripeSecretKey:     os.Getenv("STRIPE_SECRET_KEY"),
-		StripePublicKey:     os.Getenv("STRIPE_PUBLIC_KEY"),
-		StripeWebhookSecret: os.Getenv("STRIPE_WEBHOOK_SECRET"),
-		ShippoAPIKey:        os.Getenv("SHIPPO_API_KEY"),
-		AuthFingerprintKey:  os.Getenv("AUTH_FINGERPRINT_KEY"),
-		BringAPIUID:         os.Getenv("BRING_API_UID"),
-		BringAPIKey:         os.Getenv("BRING_API_KEY"),
-		BringCustomerNumber: os.Getenv("BRING_CUSTOMER_NUMBER"),
-		ShippoWebhookSecret: os.Getenv("SHIPPO_WEBHOOK_SECRET"),
-		SlackSigningSecret:  os.Getenv("SLACK_SIGNING_SECRET"),
-		AdminAPIKey:         os.Getenv("ADMIN_API_KEY"),
-		MaxOrderCents:       loadMaxOrderCents(),
+		APIPort:                      apiPort,
+		APIURL:                       apiURL,
+		AppURL:                       getEnvOrDefault("APP_URL", apiURL),
+		SSHPort:                      getEnvOrDefault("SSH_PORT", "23457"),
+		Environment:                  getEnvOrDefault("ENVIRONMENT", "development"),
+		DatabaseURL:                  getEnvOrDefault("DATABASE_URL", "terminalshop.db"),
+		JWTSecret:                    os.Getenv("JWT_SECRET"),
+		StripeSecretKey:              os.Getenv("STRIPE_SECRET_KEY"),
+		StripePublicKey:              os.Getenv("STRIPE_PUBLIC_KEY"),
+		StripeWebhookSecret:          os.Getenv("STRIPE_WEBHOOK_SECRET"),
+		ShippoAPIKey:                 os.Getenv("SHIPPO_API_KEY"),
+		AuthFingerprintKey:           os.Getenv("AUTH_FINGERPRINT_KEY"),
+		BringAPIUID:                  os.Getenv("BRING_API_UID"),
+		BringAPIKey:                  os.Getenv("BRING_API_KEY"),
+		BringCustomerNumber:          os.Getenv("BRING_CUSTOMER_NUMBER"),
+		ShippoWebhookSecret:          os.Getenv("SHIPPO_WEBHOOK_SECRET"),
+		SlackSigningSecret:           os.Getenv("SLACK_SIGNING_SECRET"),
+		AdminAPIKey:                  os.Getenv("ADMIN_API_KEY"),
+		MaxOrderCents:                loadMaxOrderCents(),
+		Abandoned3DSThresholdMinutes: loadAbandoned3DSThresholdMinutes(),
 	}
 
 	if err := cfg.validate(); err != nil {
@@ -150,3 +153,26 @@ func loadMaxOrderCents() int {
 	}
 	return n
 }
+
+// loadAbandoned3DSThresholdMinutes read ABANDONED_3DS_THRESHOLD_MINUTES.
+// The abandoned-3DS sweep only flips requires_action rows whose updated_at iconfigs
+// older than this many minutes. Default 30 min. Values below 1 fall back to
+// the default so a typo cannot collapse the grace window the TUI polls inside.
+func loadAbandoned3DSThresholdMinutes() int {
+	const defaultMinutes = 30
+	raw := os.Getenv("ABANDONED_3DS_THRESHOLD_MINUTES")
+	if raw == "" {
+		return defaultMinutes
+	}
+	n, err := strconv.Atoi(raw)
+	if err != nil || n < 1 {
+		slog.Warn("invalid ABANDONED_3DS_THRESHOLD_MINUTES, falling back",
+			"raw", raw, "default", defaultMinutes)
+		return defaultMinutes
+	}
+	if n < 10 {
+		slog.Warn("ABANDONED_3DS_THRESHOLD_MINUTES below 10 may race in-flight 3ds challenges",
+			"value", n)
+	}
+	return n
+}

pkg/config/config_test.go

@@ -1,16 +1,30 @@
 package config
 
 import (
+	"io"
+	"log/slog"
+	"os"
 	"testing"
 )
 
+// TestMain silences the package's slog warnings so the negative/garbage
+// env-var cases plus the sub-10 valid-minimum case don't spam test output.
+// The actual fall-back behavior is still asserted via the case tables.
+func TestMain(m *testing.M) {
+	prev := slog.Default()
+	slog.SetDefault(slog.New(slog.NewTextHandler(io.Discard, nil)))
+	code := m.Run()
+	slog.SetDefault(prev)
+	os.Exit(code)
+}
+
 func TestLoadMaxOrderCents(t *testing.T) {
 	cases := []struct {
 		name string
 		env  string // "" means unset
 		want int
 	}{
-		{"unset uses default", "", 20000},
+		{"empty falls back to default", "", 20000},
 		{"explicit zero disables", "0", 0},
 		{"valid override", "50000", 50000},
 		{"negative falls back to default", "-1", 20000},
@@ -32,3 +46,33 @@ func TestLoadMaxOrderCents(t *testing.T) {
 		})
 	}
 }
+
+// TestLoadAbandoned3DSThresholdMinutes covers the env-parsing surface for
+// the sweep threshold. Zero and negative fall back to the default (unlike
+// MaxOrderCents where zero is a deliberate off-switch) because a zero
+// threshold would sweep every requires_action row on the first tick and
+// race the customer's in-progress challenge.
+func TestLoadAbandoned3DSThresholdMinutes(t *testing.T) {
+	cases := []struct {
+		name string
+		env  string // "" means unset
+		want int
+	}{
+		{"empty falls back to default", "", 30},
+		{"valid override", "45", 45},
+		{"zero falls back to default", "0", 30},
+		{"negative falls back to default", "-5", 30},
+		{"garbage falls back to default", "half an hour", 30},
+		{"valid minimum (warns)", "1", 1},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Setenv("ABANDONED_3DS_THRESHOLD_MINUTES", tc.env)
+			got := loadAbandoned3DSThresholdMinutes()
+			if got != tc.want {
+				t.Errorf("loadAbandoned3DSThresholdMinutes() = %d, want %d", got, tc.want)
+			}
+		})
+	}
+}

pkg/database/seed.go

@@ -4,8 +4,9 @@ import (
 	"fmt"
 	"log"
 
-	"gorm.io/gorm"
 	"terminalShop/pkg/models"
+
+	"gorm.io/gorm"
 )
 
 // Seed populates the database with initial data
@@ -27,7 +28,7 @@ func Seed(db *gorm.DB) error {
 			RoastType:   "Dark Roast",
 			Ounces:      2,
 			BeanType:    "Arabica",
-			Price:       350, // $3.50
+			Price:       1800, // $18.00
 			Color:       "#8B4513",
 			Description: "Bold and intense coffee with a rich crema",
 		},
@@ -36,7 +37,7 @@ func Seed(db *gorm.DB) error {
 			RoastType:   "Medium Roast",
 			Ounces:      8,
 			BeanType:    "Arabica",
-			Price:       400, // $4.00
+			Price:       2200, // $22.00
 			Color:       "#A0522D",
 			Description: "Smooth and balanced espresso diluted with hot water",
 		},
@@ -45,7 +46,7 @@ func Seed(db *gorm.DB) error {
 			RoastType:   "Medium Roast",
 			Ounces:      6,
 			BeanType:    "Arabica",
-			Price:       450, // $4.50
+			Price:       2200, // $22.00
 			Color:       "#C4A574",
 			Description: "Espresso with steamed milk and a thick layer of foam",
 		},
@@ -54,7 +55,7 @@ func Seed(db *gorm.DB) error {
 			RoastType:   "Medium Roast",
 			Ounces:      12,
 			BeanType:    "Arabica",
-			Price:       500, // $5.00
+			Price:       2500, // $25.00
 			Color:       "#D2B48C",
 			Description: "Creamy espresso with plenty of steamed milk and a touch of foam",
 		},
@@ -63,7 +64,7 @@ func Seed(db *gorm.DB) error {
 			RoastType:   "Dark Roast",
 			Ounces:      12,
 			BeanType:    "Arabica",
-			Price:       550, // $5.50
+			Price:       3000, // $30.00
 			Color:       "#8B4513",
 			Description: "Chocolate and espresso combined with steamed milk. Sweet and indulgent.",
 		},
@@ -72,7 +73,7 @@ func Seed(db *gorm.DB) error {
 			RoastType:   "Dark Roast",
 			Ounces:      3,
 			BeanType:    "Robusta Blend",
-			Price:       425, // $4.25
+			Price:       1800, // $18.00
 			Color:       "#DAA520",
 			Description: "Espresso 'marked' with a dollop of foamed milk. Small but mighty, like a tiny caffeinated warrior.",
 		},

pkg/models/order.go

@@ -10,13 +10,14 @@ import (
 type OrderStatus string
 
 const (
-	OrderStatusPending   OrderStatus = "pending"
-	OrderStatusPaid      OrderStatus = "paid"
-	OrderStatusShipped   OrderStatus = "shipped"
-	OrderStatusDelivered OrderStatus = "delivered"
-	OrderStatusCancelled OrderStatus = "cancelled"
-	OrderStatusRefunded  OrderStatus = "refunded"
-	OrderStatusFailed    OrderStatus = "failed"
+	OrderStatusPending        OrderStatus = "pending"
+	OrderStatusRequiresAction OrderStatus = "requires_action"
+	OrderStatusPaid           OrderStatus = "paid"
+	OrderStatusShipped        OrderStatus = "shipped"
+	OrderStatusDelivered      OrderStatus = "delivered"
+	OrderStatusCancelled      OrderStatus = "cancelled"
+	OrderStatusRefunded       OrderStatus = "refunded"
+	OrderStatusFailed         OrderStatus = "failed"
 )
 
 type TrackingStatus string

pkg/models/order_display.go

@@ -35,6 +35,8 @@ func (order *Order) DisplayState() string {
 	switch order.Status {
 	case OrderStatusPending:
 		return "Awaiting payment"
+	case OrderStatusRequiresAction:
+		return "Awaiting authentication"
 	case OrderStatusPaid:
 		if order.TrackingNumber == "" {
 			return "Paid * awaiting label"
@@ -77,6 +79,8 @@ func (order *Order) DisplayKind() DisplayKind {
 	switch order.Status {
 	case OrderStatusPending:
 		return DisplayKindNeutral
+	case OrderStatusRequiresAction:
+		return DisplayKindNeutral
 	case OrderStatusPaid:
 		return DisplayKindAccent
 	case OrderStatusShipped:

pkg/models/order_display_test.go

@@ -14,6 +14,7 @@ func TestOrderDisplayState(t *testing.T) {
 		kind  DisplayKind
 	}{
 		{"pending", Order{Status: OrderStatusPending}, "Awaiting payment", DisplayKindNeutral},
+		{"requires_action", Order{Status: OrderStatusRequiresAction}, "Awaiting authentication", DisplayKindNeutral},
 		{"paid no tracking", Order{Status: OrderStatusPaid}, "Paid * awaiting label", DisplayKindAccent},
 		{"paid with tracking, no event", Order{Status: OrderStatusPaid, TrackingNumber: "12999"}, "Paid", DisplayKindAccent},
 		{"Paid pre-transit", Order{Status: OrderStatusPaid, TrackingNumber: "12999", TrackingStatus: TrackingStatusPreTransit}, "Paid * ready to ship", DisplayKindAccent},

pkg/tui/model.go

@@ -75,7 +75,6 @@ type Model struct {
 	Fingerprint        string
 	AccessToken        string
 	AuthFingerprintKey string // shared secret for /auth/token refresh
-	StripePublicKey    string
 
 	// One-shop auth command - capture pubKeyStr in closure, not stored on Model
 	authCmd tea.Cmd
@@ -736,7 +735,6 @@ func (m Model) saveCardOnlyCmd(form PaymentFormCompleteMsg) tea.Cmd {
 		if m.APIClient == nil {
 			return CardSavedForReviewMsg{Err: fmt.Errorf("API client not available")}
 		}
-		stripe.Key = m.StripePublicKey
 		tok, err := stripetoken.New(&stripe.TokenParams{
 			Card: &stripe.CardParams{
 				Name:       stripe.String(form.CardName),
@@ -905,11 +903,12 @@ func NewModel(username string) Model {
 }
 
 // NewModelWithAuth creates a new model with user authentication context.
-func NewModelWithAuth(fingerprint string, pubKeyStr string, apiURL string, clientSecret string, stripePublicKey string) Model {
+// The publishable Stripe key is wired into stripe.Key once at startup in
+// the SSH binary's main, so it is not threaded through here.
+func NewModelWithAuth(fingerprint string, pubKeyStr string, apiURL string, clientSecret string) Model {
 	m := NewModel("")
 	m.Fingerprint = fingerprint
 	m.AuthFingerprintKey = clientSecret
-	m.StripePublicKey = stripePublicKey
 	m.currentPage = splashPage
 	if apiURL != "" {
 		m.APIClient = api.NewClient(apiURL, "")

pkg/utils/response.go

@@ -8,8 +8,8 @@ import (
 
 // SuccessResponse represents a successful API response
 type SuccessResponse struct {
-	Success bool        `json:"success"`
-	Data    interface{} `json:"data"`
+	Success bool `json:"success"`
+	Data    any  `json:"data"`
 }
 
 // ErrorResponse represents an error API response
@@ -20,13 +20,13 @@ type ErrorResponse struct {
 
 // Error contains error details
 type Error struct {
-	Code    string                 `json:"code"`
-	Message string                 `json:"message"`
-	Details map[string]interface{} `json:"details,omitempty"`
+	Code    string         `json:"code"`
+	Message string         `json:"message"`
+	Details map[string]any `json:"details,omitempty"`
 }
 
 // RespondSuccess sends a successful JSON response
-func RespondSuccess(w http.ResponseWriter, statusCode int, data interface{}) {
+func RespondSuccess(w http.ResponseWriter, statusCode int, data any) {
 	w.Header().Set("Content-Type", "application/json")
 	w.WriteHeader(statusCode)
 
@@ -39,7 +39,7 @@ func RespondSuccess(w http.ResponseWriter, statusCode int, data interface{}) {
 }
 
 // RespondError sends an error JSON response
-func RespondError(w http.ResponseWriter, statusCode int, code, message string, details map[string]interface{}) {
+func RespondError(w http.ResponseWriter, statusCode int, code, message string, details map[string]any) {
 	w.Header().Set("Content-Type", "application/json")
 	w.WriteHeader(statusCode)