feat(privacy): add privacy mode

Drop off_session from the initial PaymentIntent so the checkout charge is a Customer-Initiated Transaction (the customer is present in the TUI), not a Merchant-Initiated Transaction. MIT exemptions require a stored mandate we never capture; as a CIT, an SCA challenge surfaces as status=requires_action, the path the handler already had. The re-confirm in respondRequiresAction and the authentication_required error branch remain as defensive fallbacks. Source: stripe-samples accept-a-payment custom-payment-flow (no off_session on customer-present confirms).

Also clarify the MAX_ORDER_CENTS TRA-ceiling anchor comment as an approximate USD/EUR figure (config.go), and carry an unrelated 1-line spend-limit input width fix in pkg/tui/account.go.

Tests: add paymentIntentNewFn stub seam, TestConvertCartIsCustomerInitiated (asserts no off_session) and TestConvertCartRequiresAction (202 + redirect + audit row).

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

api/handlers/account.go

@@ -0,0 +1,161 @@
+package handlers
+
+import (
+	"encoding/json"
+	"net/http"
+
+	"terminalShop/api/middleware"
+	"terminalShop/pkg/audit"
+	"terminalShop/pkg/database"
+	"terminalShop/pkg/models"
+	"terminalShop/pkg/utils"
+)
+
+// AccountHandler serves JWT-authed, customer-facing account-settings endpoints.
+// Unlike AdminUserHandler (X-Admin-Key gated), every route here edits the
+// logged-in user's own row, identified by the JWT user id in context.
+type AccountHandler struct {
+	// maxOrderCents is the global spend cap, needed to bound a self-limit: a
+	// customer may only TIGHTEN their effective ceiling, never raise it.
+	maxOrderCents int
+}
+
+// NewAccountHandler constructs an AccountHandler. maxOrderCents is the global
+// MAX_ORDER_CENTS, wired from cfg in routes.SetupRoutes (same value the cart
+// handler receives).
+func NewAccountHandler(maxOrderCents int) *AccountHandler {
+	return &AccountHandler{maxOrderCents: maxOrderCents}
+}
+
+// SetSpendLimit sets or clears the logged-in user's self-service spend limit
+// (User.SelfLimitCents). Body: {"self_limit_cents": <int|null>}.
+//   - null -> clears the self-limit; the user reverts to the admin/global cap
+//   - 0    -> a real "block everything" ceiling (NOT an off-switch; that is the
+//     whole point of a customer-set limit — it can only tighten)
+//   - >0   -> custom ceiling, must be <= the effective admin/global cap
+//
+// Security: this endpoint is JWT-authed and edits the caller's OWN row, so a
+// self-limit is LOWER-ONLY. A value above the user's effective admin/global cap
+// is rejected here (HTTP 400) so a compromised session cannot lift its own
+// ceiling; the min() fold in cart.go:ConvertCart is the authoritative second
+// guard. Negative values are rejected at the write boundary (the ConvertCart
+// read path also ignores a stray negative from a direct DB write).
+//
+// Mirrors AdminUserHandler.SetUserOrderCap but reads the user id from the JWT
+// context instead of a {id} URL param, uses a distinct body key + audit event,
+// and gates the value against the cap.
+func (h *AccountHandler) SetSpendLimit(w http.ResponseWriter, r *http.Request) {
+	db := database.GetDB().WithContext(r.Context())
+	userID := middleware.UserIDFromContext(r.Context())
+
+	var raw map[string]json.RawMessage
+	if err := json.NewDecoder(r.Body).Decode(&raw); err != nil {
+		utils.RespondError(w, http.StatusBadRequest, "INVALID_BODY", "invalid request body", nil)
+		return
+	}
+	rawLimit, ok := raw["self_limit_cents"]
+	if !ok {
+		utils.RespondError(w, http.StatusBadRequest, "MISSING_FIELD", "self_limit_cents is required (use null to clear the limit)", nil)
+		return
+	}
+
+	var limitCents *int
+	if string(rawLimit) != "null" {
+		var n int
+		if err := json.Unmarshal(rawLimit, &n); err != nil {
+			utils.RespondError(w, http.StatusBadRequest, "INVALID_BODY", "self_limit_cents must be an integer or null", nil)
+			return
+		}
+		if n < 0 {
+			utils.RespondError(w, http.StatusBadRequest, "INVALID_LIMIT", "self_limit_cents must be >= 0 (use null to clear the limit)", nil)
+			return
+		}
+		limitCents = &n
+	}
+
+	var user models.User
+	if err := db.First(&user, userID).Error; err != nil {
+		utils.RespondError(w, http.StatusNotFound, "USER_NOT_FOUND", "user not found", nil)
+		return
+	}
+
+	// A self-limit may only tighten the effective cap, never raise it. Compute
+	// the user's effective admin/global ceiling exactly as cart.go:ConvertCart
+	// does (per-user override wins when present and non-negative; an active cap
+	// is > 0). Reject any self-limit above an ACTIVE admin ceiling. When no admin
+	// ceiling is active (global disabled and no override) there is nothing to
+	// raise, so any non-negative self-limit is allowed — it can only ADD a cap.
+	if limitCents != nil {
+		adminCap := h.maxOrderCents
+		if user.MaxOrderCents != nil && *user.MaxOrderCents >= 0 {
+			adminCap = *user.MaxOrderCents
+		}
+		if adminCap > 0 && *limitCents > adminCap {
+			utils.RespondError(w, http.StatusBadRequest, "SELF_LIMIT_ABOVE_CAP", "self_limit_cents may not exceed your account spend cap", map[string]any{"self_limit_cents": *limitCents, "cap_cents": adminCap})
+			return
+		}
+	}
+
+	// Map form so a nil pointer persists SQL NULL; a struct Updates would skip it.
+	if err := db.Model(&user).Updates(map[string]any{"self_limit_cents": limitCents}).Error; err != nil {
+		utils.RespondError(w, http.StatusInternalServerError, "DATABASE_ERROR", "failed to update spend limit", nil)
+		return
+	}
+
+	audit.UserSelfLimitSet(user.ID, limitCents)
+
+	utils.RespondSuccess(w, http.StatusOK, map[string]any{
+		"user_id":          user.ID,
+		"self_limit_cents": limitCents,
+	})
+}
+
+// SetPrivacyMode sets the logged-in user's account-level privacy default
+// (User.PrivacyMode). Body: {"privacy_mode": <bool>}.
+//
+// PrivacyMode is a SOFT default, not a server-enforced guarantee: it only
+// pre-selects "don't keep" at checkout in the TUI. The checkout still sends an
+// explicit per-order intent which the backend honors (cart.go:ConvertCart) —
+// that is what lets a customer override the default with "save anyway". A
+// stricter server-enforced "never save" would be a separate mode.
+//
+// Mirrors SetSpendLimit: JWT-authed, edits the caller's OWN row.
+func (h *AccountHandler) SetPrivacyMode(w http.ResponseWriter, r *http.Request) {
+	db := database.GetDB().WithContext(r.Context())
+	userID := middleware.UserIDFromContext(r.Context())
+
+	var raw map[string]json.RawMessage
+	if err := json.NewDecoder(r.Body).Decode(&raw); err != nil {
+		utils.RespondError(w, http.StatusBadRequest, "INVALID_BODY", "invalid request body", nil)
+		return
+	}
+	rawMode, ok := raw["privacy_mode"]
+	if !ok {
+		utils.RespondError(w, http.StatusBadRequest, "MISSING_FIELD", "privacy_mode is required", nil)
+		return
+	}
+	var enabled bool
+	if err := json.Unmarshal(rawMode, &enabled); err != nil {
+		utils.RespondError(w, http.StatusBadRequest, "INVALID_BODY", "privacy_mode must be a boolean", nil)
+		return
+	}
+
+	var user models.User
+	if err := db.First(&user, userID).Error; err != nil {
+		utils.RespondError(w, http.StatusNotFound, "USER_NOT_FOUND", "user not found", nil)
+		return
+	}
+
+	// Map form so an explicit false persists (a struct Updates skips a zero bool)
+	if err := db.Model(&user).Updates(map[string]any{"privacy_mode": enabled}).Error; err != nil {
+		utils.RespondError(w, http.StatusInternalServerError, "DATABASE_ERROR", "failed to update privacy mode", nil)
+		return
+	}
+
+	audit.UserPrivacyModeSet(user.ID, enabled)
+
+	utils.RespondSuccess(w, http.StatusOK, map[string]any{
+		"user_id":      user.ID,
+		"privacy_mode": enabled,
+	})
+}

api/handlers/account_privacy_test.go

@@ -0,0 +1,61 @@
+package handlers
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"testing"
+
+	"terminalShop/pkg/database"
+	"terminalShop/pkg/models"
+)
+
+// TestSetPrivacyMode covers the account privacy toggle: enable, disable (a real
+// true->false transition, which the map-form Updates must persist), and the two
+// 400 paths (missing field, wrong type).
+func TestSetPrivacyMode(t *testing.T) {
+	cases := []struct {
+		name       string
+		body       string
+		wantStatus int
+		wantValue  bool
+	}{
+		{"enable", `{"privacy_mode": true}`, http.StatusOK, true},
+		{"disable", `{"privacy_mode": false}`, http.StatusOK, false},
+		{"missing field", `{}`, http.StatusBadRequest, false},
+		{"wrong type", `{"privacy_mode": "yes"}`, http.StatusBadRequest, false},
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			testDB, user := setupCartTestDB(t)
+			defer func() { _ = os.Remove(testDB) }()
+			defer database.ResetForTesting()
+
+			// Seed the opposite so an OK case proves a real transition (and the
+			// disable case actually exercises persisting an explicit false).
+			if tc.wantStatus == http.StatusOK {
+				if err := database.GetDB().Model(&user).Update("privacy_mode", !tc.wantValue).Error; err != nil {
+					t.Fatalf("seed privacy_mode: %v", err)
+				}
+			}
+
+			w := httptest.NewRecorder()
+			NewAccountHandler(0).SetPrivacyMode(
+				w, authRequest("PUT", "/api/v1/account/privacy-mode", []byte(tc.body), user.ID))
+
+			if w.Code != tc.wantStatus {
+				t.Fatalf("status: want %d, got %d body=%s", tc.wantStatus, w.Code, w.Body.String())
+			}
+			if tc.wantStatus != http.StatusOK {
+				return
+			}
+			var reloaded models.User
+			if err := database.GetDB().First(&reloaded, user.ID).Error; err != nil {
+				t.Fatalf("reload user: %v", err)
+			}
+			if reloaded.PrivacyMode != tc.wantValue {
+				t.Errorf("privacy_mode: want %v, got %v", tc.wantValue, reloaded.PrivacyMode)
+			}
+		})
+	}
+}

api/handlers/account_test.go

@@ -0,0 +1,118 @@
+package handlers
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+
+	"github.com/go-chi/chi/v5"
+
+	"terminalShop/api/middleware"
+	"terminalShop/pkg/database"
+	"terminalShop/pkg/models"
+)
+
+func TestSetSpendLimit(t *testing.T) {
+	const globalCap = 5000
+	cases := []struct {
+		name       string
+		seedSelf   *int // starting SelfLimitCents on the row
+		seedAdmin  *int // per-user MaxOrderCents override (effective admin cap)
+		body       string
+		wantStatus int
+		wantCode   string // error code; "" means success
+		wantLimit  *int   // expected SelfLimitCents after a successful update
+	}{
+		{"set positive under cap", nil, nil, `{"self_limit_cents":2000}`, http.StatusOK, "", intPtr(2000)},
+		{"set zero blocks all", nil, nil, `{"self_limit_cents":0}`, http.StatusOK, "", intPtr(0)},
+		{"set equal to cap", nil, nil, `{"self_limit_cents":5000}`, http.StatusOK, "", intPtr(5000)},
+		{"clear with null", intPtr(2000), nil, `{"self_limit_cents":null}`, http.StatusOK, "", nil},
+		{"overwrite existing", intPtr(2000), nil, `{"self_limit_cents":1000}`, http.StatusOK, "", intPtr(1000)},
+		{"above global cap rejected", nil, nil, `{"self_limit_cents":6000}`, http.StatusBadRequest, "SELF_LIMIT_ABOVE_CAP", nil},
+		{"under per-user override accepted", nil, intPtr(10000), `{"self_limit_cents":8000}`, http.StatusOK, "", intPtr(8000)},
+		{"above per-user override rejected", nil, intPtr(10000), `{"self_limit_cents":12000}`, http.StatusBadRequest, "SELF_LIMIT_ABOVE_CAP", nil},
+		{"negative rejected", nil, nil, `{"self_limit_cents":-1}`, http.StatusBadRequest, "INVALID_LIMIT", nil},
+		{"missing field rejected", nil, nil, `{}`, http.StatusBadRequest, "MISSING_FIELD", nil},
+		{"non-integer rejected", nil, nil, `{"self_limit_cents":"lots"}`, http.StatusBadRequest, "INVALID_BODY", nil},
+		{"malformed json rejected", nil, nil, `{`, http.StatusBadRequest, "INVALID_BODY", nil},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			user := setupOrderTestDB(t)
+			db := database.GetDB()
+			if tc.seedSelf != nil {
+				if err := db.Model(&user).Update("self_limit_cents", *tc.seedSelf).Error; err != nil {
+					t.Fatalf("seed self limit: %v", err)
+				}
+			}
+			if tc.seedAdmin != nil {
+				if err := db.Model(&user).Update("max_order_cents", *tc.seedAdmin).Error; err != nil {
+					t.Fatalf("seed admin cap: %v", err)
+				}
+			}
+
+			handler := NewAccountHandler(globalCap)
+			req := authRequest("PUT", "/api/v1/account/spend-limit", []byte(tc.body), user.ID)
+			w := httptest.NewRecorder()
+			handler.SetSpendLimit(w, req)
+
+			if w.Code != tc.wantStatus {
+				t.Fatalf("status: want %d got %d (%s)", tc.wantStatus, w.Code, w.Body.String())
+			}
+			assertErrCode(t, w, tc.wantCode)
+
+			var got models.User
+			if err := db.First(&got, user.ID).Error; err != nil {
+				t.Fatalf("reload user: %v", err)
+			}
+			if tc.wantStatus == http.StatusOK {
+				if !eqIntPtr(got.SelfLimitCents, tc.wantLimit) {
+					t.Errorf("db SelfLimitCents: want %s got %s", fmtIntPtr(tc.wantLimit), fmtIntPtr(got.SelfLimitCents))
+				}
+			} else if !eqIntPtr(got.SelfLimitCents, tc.seedSelf) {
+				// A rejected request must not mutate the column.
+				t.Errorf("rejected request changed db limit: want %s got %s", fmtIntPtr(tc.seedSelf), fmtIntPtr(got.SelfLimitCents))
+			}
+		})
+	}
+}
+
+// TestSetSpendLimit_CapDisabledAllowsAnyLimit: with no active admin ceiling
+// (global 0, no override) any non-negative self-limit is accepted — a self-limit
+// can only ADD a ceiling, so there is nothing to raise.
+func TestSetSpendLimit_CapDisabledAllowsAnyLimit(t *testing.T) {
+	user := setupOrderTestDB(t)
+	handler := NewAccountHandler(0) // global cap disabled
+	req := authRequest("PUT", "/api/v1/account/spend-limit", []byte(`{"self_limit_cents":999999}`), user.ID)
+	w := httptest.NewRecorder()
+	handler.SetSpendLimit(w, req)
+	if w.Code != http.StatusOK {
+		t.Fatalf("status: want 200 got %d (%s)", w.Code, w.Body.String())
+	}
+	var got models.User
+	if err := database.GetDB().First(&got, user.ID).Error; err != nil {
+		t.Fatalf("reload user: %v", err)
+	}
+	if !eqIntPtr(got.SelfLimitCents, intPtr(999999)) {
+		t.Errorf("db SelfLimitCents: want 999999 got %s", fmtIntPtr(got.SelfLimitCents))
+	}
+}
+
+// TestSetSpendLimit_RequireAuthGate exercises the JWT gate through a real
+// router: no user context => 401, the handler is never reached.
+func TestSetSpendLimit_RequireAuthGate(t *testing.T) {
+	setupOrderTestDB(t)
+	router := chi.NewRouter()
+	router.With(middleware.RequireAuth).
+		Put("/api/v1/account/spend-limit", NewAccountHandler(5000).SetSpendLimit)
+
+	req := httptest.NewRequest("PUT", "/api/v1/account/spend-limit", strings.NewReader(`{"self_limit_cents":1000}`))
+	w := httptest.NewRecorder()
+	router.ServeHTTP(w, req)
+	if w.Code != http.StatusUnauthorized {
+		t.Fatalf("status: want 401 got %d", w.Code)
+	}
+	assertErrCode(t, w, "UNAUTHORIZED")
+}

api/handlers/admin_users.go

@@ -0,0 +1,97 @@
+package handlers
+
+import (
+	"encoding/json"
+	"net/http"
+	"strconv"
+
+	"github.com/go-chi/chi/v5"
+
+	"terminalShop/pkg/audit"
+	"terminalShop/pkg/database"
+	"terminalShop/pkg/models"
+	"terminalShop/pkg/utils"
+)
+
+// AdminUserHandler serves admin-gated user-administration endpoints. Routes that
+// use it are mounted behind middleware.RequireAdmin (X-Admin-Key), not the JWT
+// auth used by customer-facing endpoints.
+type AdminUserHandler struct{}
+
+// NewAdminUserHandler constructs an AdminUserHandler.
+func NewAdminUserHandler() *AdminUserHandler {
+	return &AdminUserHandler{}
+}
+
+// SetUserOrderCap sets or clears a user's per-user spend-cap override
+// (User.MaxOrderCents). Body: {"max_order_cents": <int|null>}.
+//   - null  -> clears the override; the user reverts to the global MAX_ORDER_CENTS
+//   - 0     -> per-user off-switch (disables the cap for this user)
+//   - >0    -> custom ceiling
+//
+// Negative values are rejected here at the write boundary (HTTP 400) to keep bad
+// data out of the column. The read path in cart.go:ConvertCart independently
+// defends against a negative that arrives via a direct DB write (falls back to
+// the global cap), so the two layers cover each other.
+//
+// Adapted from the admin OrderHandler.UpdateTracking pattern in
+// api/handlers/orders.go (URL id param -> body decode -> row lookup -> update ->
+// audit -> respond).
+func (h *AdminUserHandler) SetUserOrderCap(w http.ResponseWriter, r *http.Request) {
+	db := database.GetDB().WithContext(r.Context())
+
+	idStr := chi.URLParam(r, "id")
+	id, err := strconv.ParseUint(idStr, 10, 32)
+	if err != nil {
+		utils.RespondError(w, http.StatusBadRequest, "INVALID_ID", "invalid user id", nil)
+		return
+	}
+
+	// Decode raw so an explicit null (clear) is distinguishable from an absent key.
+	var raw map[string]json.RawMessage
+	if err := json.NewDecoder(r.Body).Decode(&raw); err != nil {
+		utils.RespondError(w, http.StatusBadRequest, "INVALID_BODY", "invalid request body", nil)
+		return
+	}
+	rawCap, ok := raw["max_order_cents"]
+	if !ok {
+		utils.RespondError(w, http.StatusBadRequest, "MISSING_FIELD",
+			"max_order_cents is required (use null to clear the override)", nil)
+		return
+	}
+
+	var capCents *int
+	if string(rawCap) != "null" {
+		var n int
+		if err := json.Unmarshal(rawCap, &n); err != nil {
+			utils.RespondError(w, http.StatusBadRequest, "INVALID_BODY",
+				"max_order_cents must be an integer or null", nil)
+			return
+		}
+		if n < 0 {
+			utils.RespondError(w, http.StatusBadRequest, "INVALID_CAP",
+				"max_order_cents must be >= 0 (use null to clear the override)", nil)
+			return
+		}
+		capCents = &n
+	}
+
+	var user models.User
+	if err := db.First(&user, id).Error; err != nil {
+		utils.RespondError(w, http.StatusNotFound, "USER_NOT_FOUND", "user not found", nil)
+		return
+	}
+
+	// Map form so a nil pointer persists SQL NULL; a struct Updates would skip it.
+	if err := db.Model(&user).Updates(map[string]any{"max_order_cents": capCents}).Error; err != nil {
+		utils.RespondError(w, http.StatusInternalServerError, "DATABASE_ERROR", "failed to update order cap", nil)
+		return
+	}
+
+	audit.UserOrderCapSet("admin", user.ID, capCents)
+
+	utils.RespondSuccess(w, http.StatusOK, map[string]any{
+		"user_id":         user.ID,
+		"max_order_cents": capCents,
+	})
+}

api/handlers/admin_users_test.go

@@ -0,0 +1,194 @@
+package handlers
+
+import (
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"strconv"
+	"strings"
+	"testing"
+
+	"github.com/go-chi/chi/v5"
+
+	"terminalShop/api/middleware"
+	"terminalShop/pkg/database"
+	"terminalShop/pkg/models"
+)
+
+// adminCapRequest builds a PATCH request carrying the {id} chi URL param, as the
+// admin order-cap route would. No JWT — the route is gated by RequireAdmin.
+func adminCapRequest(idParam, body string) *http.Request {
+	req := httptest.NewRequest("PATCH", "/api/v1/users/"+idParam+"/order-cap", strings.NewReader(body))
+	rc := chi.NewRouteContext()
+	rc.URLParams.Add("id", idParam)
+	return req.WithContext(contextWithRoute(req.Context(), rc))
+}
+
+func eqIntPtr(a, b *int) bool {
+	if a == nil || b == nil {
+		return a == b
+	}
+	return *a == *b
+}
+
+func fmtIntPtr(p *int) string {
+	if p == nil {
+		return "<nil>"
+	}
+	return strconv.Itoa(*p)
+}
+
+func TestSetUserOrderCap(t *testing.T) {
+	cases := []struct {
+		name       string
+		seed       *int // starting MaxOrderCents on the user row
+		body       string
+		wantStatus int
+		wantCode   string // error code; "" means success
+		wantCap    *int   // expected DB value after a successful update
+	}{
+		{"set positive", nil, `{"max_order_cents":7500}`, http.StatusOK, "", intPtr(7500)},
+		{"set zero off-switch", nil, `{"max_order_cents":0}`, http.StatusOK, "", intPtr(0)},
+		{"clear with null reverts to global", intPtr(500), `{"max_order_cents":null}`, http.StatusOK, "", nil},
+		{"overwrite existing value", intPtr(500), `{"max_order_cents":12000}`, http.StatusOK, "", intPtr(12000)},
+		{"negative rejected", nil, `{"max_order_cents":-1}`, http.StatusBadRequest, "INVALID_CAP", nil},
+		{"missing field rejected", nil, `{}`, http.StatusBadRequest, "MISSING_FIELD", nil},
+		{"non-integer rejected", nil, `{"max_order_cents":"lots"}`, http.StatusBadRequest, "INVALID_BODY", nil},
+		{"malformed json rejected", nil, `{`, http.StatusBadRequest, "INVALID_BODY", nil},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			user := setupOrderTestDB(t)
+			db := database.GetDB()
+			if tc.seed != nil {
+				if err := db.Model(&user).Update("max_order_cents", *tc.seed).Error; err != nil {
+					t.Fatalf("seed cap: %v", err)
+				}
+			}
+
+			handler := NewAdminUserHandler()
+			req := adminCapRequest(strconv.FormatUint(uint64(user.ID), 10), tc.body)
+			w := httptest.NewRecorder()
+			handler.SetUserOrderCap(w, req)
+
+			if w.Code != tc.wantStatus {
+				t.Fatalf("status: want %d got %d (%s)", tc.wantStatus, w.Code, w.Body.String())
+			}
+
+			var resp struct {
+				Error struct {
+					Code string `json:"code"`
+				} `json:"error"`
+			}
+			_ = json.Unmarshal(w.Body.Bytes(), &resp)
+			if resp.Error.Code != tc.wantCode {
+				t.Errorf("error code: want %q got %q", tc.wantCode, resp.Error.Code)
+			}
+
+			var got models.User
+			if err := db.First(&got, user.ID).Error; err != nil {
+				t.Fatalf("reload user: %v", err)
+			}
+			if tc.wantStatus == http.StatusOK {
+				if !eqIntPtr(got.MaxOrderCents, tc.wantCap) {
+					t.Errorf("db MaxOrderCents: want %s got %s", fmtIntPtr(tc.wantCap), fmtIntPtr(got.MaxOrderCents))
+				}
+			} else if !eqIntPtr(got.MaxOrderCents, tc.seed) {
+				// A rejected request must not mutate the column.
+				t.Errorf("rejected request changed db cap: want %s got %s", fmtIntPtr(tc.seed), fmtIntPtr(got.MaxOrderCents))
+			}
+		})
+	}
+}
+
+func TestSetUserOrderCap_InvalidID(t *testing.T) {
+	setupOrderTestDB(t)
+	w := httptest.NewRecorder()
+	NewAdminUserHandler().SetUserOrderCap(w, adminCapRequest("abc", `{"max_order_cents":100}`))
+	if w.Code != http.StatusBadRequest {
+		t.Fatalf("status: want 400 got %d", w.Code)
+	}
+	assertErrCode(t, w, "INVALID_ID")
+}
+
+func TestSetUserOrderCap_UserNotFound(t *testing.T) {
+	setupOrderTestDB(t)
+	w := httptest.NewRecorder()
+	NewAdminUserHandler().SetUserOrderCap(w, adminCapRequest("99999", `{"max_order_cents":100}`))
+	if w.Code != http.StatusNotFound {
+		t.Fatalf("status: want 404 got %d", w.Code)
+	}
+	assertErrCode(t, w, "USER_NOT_FOUND")
+}
+
+// TestSetUserOrderCap_AdminGate exercises the RequireAdmin middleware through a
+// real router (the handler-direct tests above bypass middleware).
+func TestSetUserOrderCap_AdminGate(t *testing.T) {
+	user := setupOrderTestDB(t)
+	idStr := strconv.FormatUint(uint64(user.ID), 10)
+
+	router := func() http.Handler {
+		r := chi.NewRouter()
+		r.With(middleware.RequireAdmin).
+			Patch("/api/v1/users/{id}/order-cap", NewAdminUserHandler().SetUserOrderCap)
+		return r
+	}
+	newReq := func() *http.Request {
+		return httptest.NewRequest("PATCH", "/api/v1/users/"+idStr+"/order-cap",
+			strings.NewReader(`{"max_order_cents":100}`))
+	}
+
+	t.Run("disabled when ADMIN_API_KEY unset", func(t *testing.T) {
+		t.Setenv("ADMIN_API_KEY", "")
+		w := httptest.NewRecorder()
+		router().ServeHTTP(w, newReq())
+		if w.Code != http.StatusServiceUnavailable {
+			t.Fatalf("status: want 503 got %d", w.Code)
+		}
+		assertErrCode(t, w, "ADMIN_DISABLED")
+	})
+
+	t.Run("rejects wrong key", func(t *testing.T) {
+		t.Setenv("ADMIN_API_KEY", "secret")
+		req := newReq()
+		req.Header.Set("X-Admin-Key", "nope")
+		w := httptest.NewRecorder()
+		router().ServeHTTP(w, req)
+		if w.Code != http.StatusUnauthorized {
+			t.Fatalf("status: want 401 got %d", w.Code)
+		}
+		assertErrCode(t, w, "UNAUTHORIZED")
+	})
+
+	t.Run("accepts correct key", func(t *testing.T) {
+		t.Setenv("ADMIN_API_KEY", "secret")
+		req := newReq()
+		req.Header.Set("X-Admin-Key", "secret")
+		w := httptest.NewRecorder()
+		router().ServeHTTP(w, req)
+		if w.Code != http.StatusOK {
+			t.Fatalf("status: want 200 got %d (%s)", w.Code, w.Body.String())
+		}
+		var got models.User
+		if err := database.GetDB().First(&got, user.ID).Error; err != nil {
+			t.Fatalf("reload user: %v", err)
+		}
+		if !eqIntPtr(got.MaxOrderCents, intPtr(100)) {
+			t.Errorf("db MaxOrderCents: want 100 got %s", fmtIntPtr(got.MaxOrderCents))
+		}
+	})
+}
+
+func assertErrCode(t *testing.T, w *httptest.ResponseRecorder, want string) {
+	t.Helper()
+	var resp struct {
+		Error struct {
+			Code string `json:"code"`
+		} `json:"error"`
+	}
+	_ = json.Unmarshal(w.Body.Bytes(), &resp)
+	if resp.Error.Code != want {
+		t.Errorf("error code: want %q got %q", want, resp.Error.Code)
+	}
+}

api/handlers/cart.go

@@ -4,6 +4,8 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
+	"io"
+	"log/slog"
 	"net/http"
 	"strconv"
 	"time"
@@ -35,6 +37,16 @@ type CartHandler struct {
 // audit rows (audit.EventOrderRequiresAction) so the cap stays migration-free.
 const maxAuthIssuances = 4
 
+// paymentIntentNewFn lets tests stub the Stripe create call without spinning
+// up an httptest backend. Production callers go straight through to the real
+// paymentintent.New. Mirrors paymentIntentGetFn in reconcile.go.
+var paymentIntentNewFn = paymentintent.New
+
+var (
+	paymentMethodNewFn    = paymentmethod.New
+	paymentMethodDetachFn = paymentmethod.Detach
+)
+
 // 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 {
@@ -263,6 +275,16 @@ func (h *CartHandler) ClearCart(w http.ResponseWriter, r *http.Request) {
 	})
 }
 
+// ConvertCartRequest carries the optional privacy-checkout controls. The body
+// is optional: a saved.card checkout sends nothing and both field stay zero.
+// Ephemeral opts a single order into privacy mode (ont-time card, no Card row,
+// PM detached after settle); CardToken supplies that one-time card. A user with
+// PrivacyMode set is ephemeral regardless of the flag.
+type ConvertCartRequest struct {
+	Ephemeral bool   `json:"ephemeral"`
+	CardToken string `json:"card_token"`
+}
+
 func (h *CartHandler) ConvertCart(w http.ResponseWriter, r *http.Request) {
 	db := database.GetDB().WithContext(r.Context())
 	userID := middleware.UserIDFromContext(r.Context())
@@ -271,6 +293,12 @@ func (h *CartHandler) ConvertCart(w http.ResponseWriter, r *http.Request) {
 	defer span.End()
 	r = r.WithContext(ctx)
 
+	var req ConvertCartRequest
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil && err != io.EOF {
+		utils.RespondError(w, http.StatusBadRequest, "INVALID_JSON", "invalid request body", nil)
+		return
+	}
+
 	cart, err := getOrCreateCart(r.Context(), userID)
 	if err != nil {
 		middleware.RecordCartConversion("cart_lookup_failed")
@@ -293,12 +321,6 @@ func (h *CartHandler) ConvertCart(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	if cart.CardID == nil {
-		middleware.RecordCartConversion("validation_missing_card")
-		utils.RespondError(w, http.StatusBadRequest, "VALIDATION_ERROR", "payment card is required", nil)
-		return
-	}
-
 	var address models.Address
 	if err := db.First(&address, *cart.AddressID).Error; err != nil {
 		middleware.RecordCartConversion("validation_invalid_address")
@@ -306,23 +328,6 @@ func (h *CartHandler) ConvertCart(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	var card models.Card
-	if err := db.First(&card, *cart.CardID).Error; err != nil {
-		middleware.RecordCartConversion("validation_invalid_card")
-		utils.RespondError(w, http.StatusBadRequest, "INVALID_CARD", "payment card not found", nil)
-		return
-	}
-
-	if card.IsStorageExpired(time.Now()) {
-		middleware.RecordCartConversion("validation_card_expired")
-		if err := expireStoredCard(db, &card); err != nil {
-			utils.RespondError(w, http.StatusInternalServerError, "INTERNAL_ERROR", "failed to expire card", nil)
-			return
-		}
-		respondCardStorageExpired(w)
-		return
-	}
-
 	var user models.User
 	if err := db.First(&user, userID).Error; err != nil {
 		middleware.RecordCartConversion("user_not_found")
@@ -330,39 +335,86 @@ func (h *CartHandler) ConvertCart(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	// Ensure the user has a Stripe customer (shared helper with cards handler).
-	if err := ensureStripeCustomer(db, &user); err != nil {
-		middleware.RecordCartConversion("stripe_customer_failed")
-		utils.RespondError(w, http.StatusInternalServerError, "STRIPE_ERROR", "failed to create stripe customer", nil)
-		return
-	}
+	// Privacy mode is a SOFT default enforced in the TUI, not here: the backend
+	// trusts the checkout's explicit per-order intent so a customer can override
+	// their account default with "save anyway" at checkout. See
+	// AccountHandler.SetPrivacyMode.
+	ephemeral := req.Ephemeral
 
-	// All cards are now saved as pm_ PaymentMethods. This branch handles any
-	// legacy tok_ records that predate the server-side tokenization refactor.
-	paymentMethodID := card.StripePaymentID
-	if len(paymentMethodID) >= 3 && paymentMethodID[:3] == "tok" {
-		pm, pmErr := paymentmethod.New(&stripe.PaymentMethodParams{
-			Type: stripe.String("card"),
-			Card: &stripe.PaymentMethodCardParams{
-				Token: stripe.String(paymentMethodID),
-			},
-		})
-		if pmErr != nil {
-			utils.RespondError(w, http.StatusInternalServerError, "STRIPE_ERROR", "failed to create payment method", nil)
+	var card models.Card
+	var paymentMethodID string
+	if ephemeral {
+		if req.CardToken == "" {
+			middleware.RecordCartConversion("validation_missing_card")
+			utils.RespondError(w, http.StatusBadRequest, "VALIDATION_ERROR", "card token is required for private checkout", nil)
 			return
 		}
-		if _, attachErr := paymentmethod.Attach(pm.ID, &stripe.PaymentMethodAttachParams{
-			Customer: stripe.String(user.StripeCustomerID),
-		}); attachErr != nil {
-			utils.RespondError(w, http.StatusInternalServerError, "STRIPE_ERROR", "failed to attach payment method", nil)
+		pm, pmerr := paymentMethodNewFn(&stripe.PaymentMethodParams{
+			Type: stripe.String("card"),
+			Card: &stripe.PaymentMethodCardParams{
+				Token: stripe.String(req.CardToken),
+			},
+		})
+		if pmerr != nil {
+			middleware.RecordCartConversion("stripe_error")
+			utils.RespondError(w, http.StatusBadRequest, "STRIPE_ERROR", "failed to create payment method", nil)
 			return
 		}
 		paymentMethodID = pm.ID
-		card.StripePaymentID = pm.ID
-		if err := db.Save(&card).Error; err != nil {
-			utils.RespondError(w, http.StatusInternalServerError, "INTERNAL_ERROR", "failed to save card", nil)
+	} else {
+		if cart.CardID == nil {
+			middleware.RecordCartConversion("validation_missing_card")
+			utils.RespondError(w, http.StatusBadRequest, "VALIDATION_ERROR", "payment card is required", nil)
 			return
 		}
+
+		if err := db.First(&card, *cart.CardID).Error; err != nil {
+			middleware.RecordCartConversion("validation_invalid_card")
+			utils.RespondError(w, http.StatusBadRequest, "INVALID_CARD", "payment card not found", nil)
+			return
+		}
+
+		if card.IsStorageExpired(time.Now()) {
+			middleware.RecordCartConversion("validation_card_expired")
+			if err := expireStoredCard(db, &card); err != nil {
+				utils.RespondError(w, http.StatusInternalServerError, "INTERNAL_ERROR", "failed to expire card", nil)
+				return
+			}
+			respondCardStorageExpired(w)
+			return
+		}
+
+		if err := ensureStripeCustomer(db, &user); err != nil {
+			middleware.RecordCartConversion("stripe_customer_failed")
+			utils.RespondError(w, http.StatusInternalServerError, "STRIPE_ERROR", "failed to create stripe customer", nil)
+			return
+		}
+
+		paymentMethodID = card.StripePaymentID
+		if len(paymentMethodID) >= 3 && paymentMethodID[:3] == "tok" {
+			pm, pmErr := paymentmethod.New(&stripe.PaymentMethodParams{
+				Type: stripe.String("card"),
+				Card: &stripe.PaymentMethodCardParams{
+					Token: stripe.String(paymentMethodID),
+				},
+			})
+			if pmErr != nil {
+				utils.RespondError(w, http.StatusInternalServerError, "STRIPE_ERROR", "failed to create payment method", nil)
+				return
+			}
+			if _, attachErr := paymentmethod.Attach(pm.ID, &stripe.PaymentMethodAttachParams{
+				Customer: stripe.String(user.StripeCustomerID),
+			}); attachErr != nil {
+				utils.RespondError(w, http.StatusInternalServerError, "STRIPE_ERROR", "failed to attach payment method", nil)
+				return
+			}
+			paymentMethodID = pm.ID
+			card.StripePaymentID = pm.ID
+			if err := db.Save(&card).Error; err != nil {
+				utils.RespondError(w, http.StatusInternalServerError, "INTERNAL_ERROR", "failed to save card", nil)
+				return
+			}
+		}
 	}
 
 	var subtotal int
@@ -380,14 +432,46 @@ func (h *CartHandler) ConvertCart(w http.ResponseWriter, r *http.Request) {
 
 	total := subtotal + cart.ShippingCost
 
-	if h.maxOrderCents > 0 && total > h.maxOrderCents {
+	// Per-user overridable spend cap. The override may raise OR lower the global
+	// cap — operators set it in both directions deliberately. A negative override
+	// is nonsense: ignore it and fall back to the global so an erroneous DB write
+	// cannot silently disable a fraud control (mirrors loadMaxOrderCents in
+	// pkg/config/config.go, which defaults a negative MAX_ORDER_CENTS). An explicit
+	// 0 is a valid per-user off-switch (same semantics as the global).
+	capCents := h.maxOrderCents
+	if user.MaxOrderCents != nil {
+		if *user.MaxOrderCents < 0 {
+			slog.Warn("ignoring negative per-user order cap, using global",
+				"user_id", user.ID,
+				"user_cap_cents", *user.MaxOrderCents,
+				"global_cap_cents", h.maxOrderCents)
+		} else {
+			capCents = *user.MaxOrderCents
+		}
+	}
+
+	// A user-set self-limit may only TIGHTEN the effective cap, never raise it.
+	// a compromised account must not be able to lift its own ceiling to drain a
+	// stolen card. Unlike the admin/global cap (where 0 is an off-switch), a
+	// present self-limit always activates a ceiling, a self-limit of 0 means
+	// "block everything", not "disable", so it folds in via min() and can only
+	// lower capCents. A negative value is ignored (mirrors the maxOrderCents
+	// guard above); this min() is the authoritative lower-only guard.
+	capActive := capCents > 0
+	if user.SelfLimitCents != nil && *user.SelfLimitCents >= 0 {
+		if self := *user.SelfLimitCents; !capActive || self < capCents {
+			capCents = self
+		}
+		capActive = true
+	}
+	if capActive && total > capCents {
 		middleware.RecordCartConversion("validation_over_limit")
-		audit.CartRejected(userID, total, h.maxOrderCents)
+		audit.CartRejected(userID, total, capCents)
 		utils.RespondError(w, http.StatusBadRequest, "CART_OVER_LIMIT",
-			fmt.Sprintf("order total must be at most $%.2f", float64(h.maxOrderCents)/100),
+			fmt.Sprintf("order total must be at most $%.2f", float64(capCents)/100),
 			map[string]any{
 				"total_cents": total,
-				"limit_cents": h.maxOrderCents,
+				"limit_cents": capCents,
 			})
 		return
 	}
@@ -404,6 +488,7 @@ func (h *CartHandler) ConvertCart(w http.ResponseWriter, r *http.Request) {
 		UserID:          user.ID,
 		CardID:          card.ID,
 		StripePaymentID: "",
+		Ephemeral:       ephemeral,
 		Status:          models.OrderStatusPending,
 		Subtotal:        subtotal,
 		ShippingCost:    cart.ShippingCost,
@@ -427,14 +512,23 @@ func (h *CartHandler) ConvertCart(w http.ResponseWriter, r *http.Request) {
 
 	audit.OrderCreated(userID, order.ID, total)
 
-	// Charge the card. The idempotency key is tied to the order ID so retries
-	// never produce a double charge.
+	// Charge the card. This is a Customer-Initiated Transaction (CIT): the
+	// customer is present in the TUI at checkout. We deliberately do NOT set
+	// OffSession — that flag marks a Merchant-Initiated Transaction (MIT),
+	// which under PSD2/SCA may only claim an exemption when a stored mandate
+	// authorises the merchant to charge while the customer is away. We capture
+	// no mandate and run no recurring billing, so MIT would misrepresent the
+	// transaction type. As a CIT, an SCA challenge surfaces as
+	// pi.Status == requires_action (handled below), not as an
+	// authentication_required error. See docs/sca-psd2-compliance.md "Gap 1".
+	// Reference: stripe-samples accept-a-payment custom-payment-flow —
+	// php/public/google-pay.php drives 3DS off status==requires_action and sets
+	// no off_session on a customer-present confirm.
+	// The idempotency key is tied to the order ID so retries never double charge.
 	piParams := &stripe.PaymentIntentParams{
 		Amount:             stripe.Int64(int64(total)),
 		Currency:           stripe.String(string(stripe.CurrencyUSD)),
-		Customer:           stripe.String(user.StripeCustomerID),
 		PaymentMethod:      stripe.String(paymentMethodID),
-		OffSession:         stripe.Bool(true),
 		PaymentMethodTypes: stripe.StringSlice([]string{"card"}),
 		ReturnURL:          stripe.String(h.appURL + "/post-3ds"),
 		Confirm:            stripe.Bool(true),
@@ -456,12 +550,21 @@ func (h *CartHandler) ConvertCart(w http.ResponseWriter, r *http.Request) {
 		"order_id": fmt.Sprintf("%d", order.ID),
 	}
 
+	if !ephemeral {
+		piParams.Customer = stripe.String(user.StripeCustomerID)
+	}
+
 	stripeStart := time.Now()
-	pi, err := paymentintent.New(piParams)
+	pi, err := paymentIntentNewFn(piParams)
 	stripeDur := time.Since(stripeStart).Seconds()
 	if err != nil {
 		middleware.ObserveStripeRequest("payment_intent_create", "error", stripeDur)
 		if stripeErr, ok := err.(*stripe.Error); ok {
+			// Defensive fallback: as CIT (no off_session) Stripe normally
+			// signals 3DS via status=requires_action below, not via this error.
+			// authentication_required can still appear if the saved card needs
+			// auth that could not run inline; respondRequiresAction re-Confirms
+			// on-session to recover. (Pre-CIT migration this was the main path.)
 			if stripeErr.Code == stripe.ErrorCodeAuthenticationRequired && stripeErr.PaymentIntent != nil {
 				h.respondRequiresAction(w, &order, paymentMethodID, stripeErr.PaymentIntent)
 				return
@@ -522,6 +625,12 @@ func (h *CartHandler) ConvertCart(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	if ephemeral {
+		if _, derr := paymentMethodDetachFn(paymentMethodID, nil); derr != nil {
+			slog.Warn("failed to detach ephemeral payment method", "order_id", order.ID, "error", derr)
+		}
+	}
+
 	audit.OrderPaid(userID, order.ID, total, pi.ID)
 	middleware.RecordOrderCreated(string(order.Status))
 	middleware.RecordCartConversion("success")

api/handlers/cart_test.go

@@ -670,27 +670,67 @@ func TestCartIsolation(t *testing.T) {
 	}
 }
 
+// intPtr returns a pointer to i, for seeding the nullable User.MaxOrderCents
+// per-user cap override in table tests.
+func intPtr(i int) *int { return &i }
+
 func TestConvertCartLimit(t *testing.T) {
 	cases := []struct {
 		name          string
 		capCents      int
 		quantity      int
 		expectOverCap bool
+		userCap       *int // per-user admin override; nil = inherit the global capCents
+		selfLimit     *int // user self-limit; nil = none. Lower-only: tightens, never raises.
 	}{
-		{"over cap rejects", 20000, 41, true},   // $205
-		{"at cap accepts", 20000, 40, false},    // $200 boundary
-		{"under cap accepts", 20000, 39, false}, // $195
-		{"zero cap disables", 0, 1000, false},   // explicit off-switch
+		{"over cap rejects", 20000, 41, true, nil, nil},   // $205 vs global $200
+		{"at cap accepts", 20000, 40, false, nil, nil},    // $200 boundary
+		{"under cap accepts", 20000, 39, false, nil, nil}, // $195
+		{"zero cap disables", 0, 1000, false, nil, nil},   // explicit global off-switch
+		// Per-user admin override (User.MaxOrderCents) takes precedence over the global.
+		{"user override below global rejects", 20000, 12, true, intPtr(5000), nil},   // $60 > $50 user cap (global $200 would allow)
+		{"user override above global accepts", 20000, 41, false, intPtr(50000), nil}, // $205 < $500 user cap (global $200 would reject)
+		{"user override zero disables per user", 20000, 1000, false, intPtr(0), nil}, // per-user off-switch over a live global
+		{"nil override falls back to global", 20000, 41, true, nil, nil},             // explicit nil == inherit global $200
+		// A negative override is nonsense and must NOT disable the cap; it falls
+		// back to the global so a bad DB write can't void a fraud control. Here
+		// $205 > global $200 still rejects, at the GLOBAL cap (not the -1).
+		{"user override negative falls back to global", 20000, 41, true, intPtr(-1), nil},
+		// Self-limit (User.SelfLimitCents) is LOWER-ONLY: it can tighten the effective
+		// cap below the admin/global value but must never raise it.
+		{"self limit below global rejects", 20000, 12, true, nil, intPtr(5000)},                   // $60 > $50 self-limit (global $200 would allow)
+		{"self limit under accepts", 20000, 8, false, nil, intPtr(5000)},                          // $40 < $50 self-limit
+		{"self limit cannot raise above global", 20000, 50, true, nil, intPtr(30000)},             // $250: min($200 global,$300 self)=$200 still rejects
+		{"self limit tightens disabled global", 0, 12, true, nil, intPtr(5000)},                   // global off-switch, self-limit $50 still caps; $60 rejects
+		{"self limit zero blocks everything", 20000, 1, true, nil, intPtr(0)},                     // $5 > $0: self-limit 0 is "block all", NOT an off-switch
+		{"self limit negative ignored", 20000, 41, true, nil, intPtr(-1)},                         // self ignored; rejects at global $200
+		{"self limit tightens below user override", 10000, 12, true, intPtr(10000), intPtr(5000)}, // $60 > $50 self (under the $100 admin override)
 	}
 
 	for _, tc := range cases {
 		t.Run(tc.name, func(t *testing.T) {
+			// Effective cap the handler should enforce, mirroring ConvertCart:
+			// a non-negative admin override wins over the global; then a present,
+			// non-negative self-limit folds in via min() (lower-only — 0 means
+			// "block all", a negative value is ignored).
+			effectiveCap := tc.capCents
+			if tc.userCap != nil && *tc.userCap >= 0 {
+				effectiveCap = *tc.userCap
+			}
+			if tc.selfLimit != nil && *tc.selfLimit >= 0 {
+				if effectiveCap <= 0 || *tc.selfLimit < effectiveCap {
+					effectiveCap = *tc.selfLimit
+				}
+			}
+
 			testDB, user := setupCartTestDB(t)
 			defer func() { _ = os.Remove(testDB) }()
 			defer database.ResetForTesting()
 
 			db := database.GetDB()
 			user.StripeCustomerID = "cus_test_overlimit"
+			user.MaxOrderCents = tc.userCap
+			user.SelfLimitCents = tc.selfLimit
 			if err := db.Save(&user).Error; err != nil {
 				t.Fatalf("saved user: %v", err)
 			}
@@ -780,8 +820,8 @@ func TestConvertCartLimit(t *testing.T) {
 				t.Fatalf("expectOverCap=%v got code=%d errCode=%q msg=%q", tc.expectOverCap, w.Code, resp.Error.Code, resp.Error.Message)
 			}
 			if tc.expectOverCap {
-				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["limit_cents"].(float64); int(got) != effectiveCap {
+					t.Errorf("limit_cents in details: want %d, got %v", effectiveCap, resp.Error.Details["limit_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"])
@@ -791,12 +831,22 @@ func TestConvertCartLimit(t *testing.T) {
 					t.Fatalf("audit: expected cart_rejected slog line, got nothing")
 				}
 
+				// The buffer may hold more than one JSON line (e.g. the negative-
+				// override warning precedes the audit record), so scan for the
+				// cart_rejected event rather than assuming it's the only line.
 				var rec map[string]any
-				if err := json.Unmarshal(auditBuf.Bytes(), &rec); err != nil {
-					t.Fatalf("audit: decode slog record: %v\nraw: %s", err, auditBuf.String())
+				for line := range bytes.SplitSeq(bytes.TrimSpace(auditBuf.Bytes()), []byte("\n")) {
+					var m map[string]any
+					if err := json.Unmarshal(line, &m); err != nil {
+						continue
+					}
+					if m["event"] == "cart_rejected" {
+						rec = m
+						break
+					}
 				}
-				if got := rec["event"]; got != "cart_rejected" {
-					t.Errorf("audit event: want cart_rejected, got %v", got)
+				if rec == nil {
+					t.Fatalf("audit: no cart_rejected slog record found\nraw: %s", auditBuf.String())
 				}
 				if n, _ := rec["user_id"].(float64); uint(n) != user.ID {
 					t.Errorf("audit user_id: want %d, got %v", user.ID, rec["user_id"])
@@ -804,14 +854,179 @@ func TestConvertCartLimit(t *testing.T) {
 				if n, _ := rec["total_cents"].(float64); int(n) != tc.quantity*pinnedPrice {
 					t.Errorf("audit total_cents: want %d, got %v", tc.quantity*pinnedPrice, rec["total_cents"])
 				}
-				if n, _ := rec["cap_cents"].(float64); int(n) != tc.capCents {
-					t.Errorf("audit cap_cents: want %d, got %v", tc.capCents, rec["cap_cents"])
+				if n, _ := rec["cap_cents"].(float64); int(n) != effectiveCap {
+					t.Errorf("audit cap_cents: want %d, got %v", effectiveCap, rec["cap_cents"])
 				}
 			}
 		})
 	}
 }
 
+func seedConvertReadyCart(t *testing.T, user models.User) {
+	t.Helper()
+	db := database.GetDB()
+
+	user.StripeCustomerID = "cus_test_cit"
+	if err := db.Save(&user).Error; err != nil {
+		t.Fatalf("save user: %v", err)
+	}
+
+	addr := models.Address{
+		UserID: user.ID, Name: "test", Street: "1 Main St",
+		City: "PDX", State: "OR", Zip: "97201", Country: "US",
+	}
+	if err := db.Create(&addr).Error; err != nil {
+		t.Fatalf("seed address: %v", err)
+	}
+
+	card := models.Card{
+		UserID: user.ID, StripePaymentID: "pm_test_cit",
+		Last4: "4242", Brand: "Visa", ExpMonth: 12, ExpYear: 2030,
+	}
+	if err := db.Create(&card).Error; err != nil {
+		t.Fatalf("seed card: %v", err)
+	}
+	if err := db.Model(&models.Coffee{}).Where("id = ?", 4).Update("price", 500).Error; err != nil {
+		t.Fatalf("pin coffee price: %v", err)
+	}
+
+	h := NewCartHandler("", 0)
+	body, _ := json.Marshal(map[string]any{"coffee_id": 4, "quantity": 2})
+	w := httptest.NewRecorder()
+	h.SetItem(w, authRequest("PUT", "/api/v1/cart/item", body, user.ID))
+	if w.Code != http.StatusOK {
+		t.Fatalf("SetItem: %d %s", w.Code, w.Body.String())
+	}
+	body, _ = json.Marshal(map[string]any{"address_id": addr.ID})
+	w = httptest.NewRecorder()
+	h.SetAddress(w, authRequest("PUT", "/api/v1/cart/address", body, user.ID))
+	if w.Code != http.StatusOK {
+		t.Fatalf("SetAddress: %d %s", w.Code, w.Body.String())
+	}
+	body, _ = json.Marshal(map[string]any{"card_id": card.ID})
+	w = httptest.NewRecorder()
+	h.SetCard(w, authRequest("PUT", "/api/v1/cart/card", body, user.ID))
+	if w.Code != http.StatusOK {
+		t.Fatalf("SetCard: %d %s", w.Code, w.Body.String())
+	}
+}
+
+func TestConvertCartIsCustomerInitiated(t *testing.T) {
+	testDB, user := setupCartTestDB(t)
+	defer func() { _ = os.Remove(testDB) }()
+	defer database.ResetForTesting()
+
+	var gotParams *stripe.PaymentIntentParams
+	orig := paymentIntentNewFn
+	defer func() { paymentIntentNewFn = orig }()
+	paymentIntentNewFn = func(p *stripe.PaymentIntentParams) (*stripe.PaymentIntent, error) {
+		gotParams = p
+		return &stripe.PaymentIntent{ID: "pi_cit", Status: stripe.PaymentIntentStatusSucceeded}, nil
+	}
+
+	seedConvertReadyCart(t, user)
+	handler := NewCartHandler("http://localhost", 0)
+
+	w := httptest.NewRecorder()
+	handler.ConvertCart(w, authRequest("POST", "/api/v1/cart/convert", nil, user.ID))
+
+	if w.Code != http.StatusOK {
+		t.Fatalf("convert: want 200, got %d body=%s", w.Code, w.Body.String())
+	}
+	if gotParams == nil {
+		t.Fatalf("paymentIntentNewFn was never called")
+	}
+	if gotParams.OffSession != nil {
+		t.Errorf("CIT charge must not set off_session; got %v", *gotParams.OffSession)
+	}
+	if gotParams.Confirm == nil || !*gotParams.Confirm {
+		t.Error("expected Confirm=true on the charge")
+	}
+	if gotParams.ReturnURL == nil || *gotParams.ReturnURL == "" {
+		t.Error("expected ReturnURL set so redirect-based 3DS can populate next_action")
+	}
+}
+
+// TestConvertCartRequiresAction asserts that when the bank requires SCA, the
+// CIT charge returns status=requires_action (the customer-initiated shape per
+// the Stripe sample) and the handler responds 202 + redirect URL, persists the
+// order in requires_action, and records the audit event the retry cap counts.
+// next_action.redirect_to_url is pre-populated so respondRequiresAction skips
+// its re-confirm and never touches the live Stripe API (hermetic).
+func TestConvertCartRequiresAction(t *testing.T) {
+	testDB, user := setupCartTestDB(t)
+	defer func() { _ = os.Remove(testDB) }()
+	defer database.ResetForTesting()
+
+	// Wire audit persistence so the order_requires_action row actually lands
+	// (audit.db is package-global and nil unless set — see api/main.go:71).
+	// Reset to nil after so it does not leak into other tests in this package.
+	audit.SetDB(database.GetDB())
+	defer audit.SetDB(nil)
+
+	orig := paymentIntentNewFn
+	defer func() { paymentIntentNewFn = orig }()
+	paymentIntentNewFn = func(_ *stripe.PaymentIntentParams) (*stripe.PaymentIntent, error) {
+		return &stripe.PaymentIntent{
+			ID:     "pi_sca",
+			Status: stripe.PaymentIntentStatusRequiresAction,
+			NextAction: &stripe.PaymentIntentNextAction{
+				RedirectToURL: &stripe.PaymentIntentNextActionRedirectToURL{
+					URL: "https://hooks.stripe.com/3ds/test",
+				},
+			},
+		}, nil
+	}
+
+	seedConvertReadyCart(t, user)
+	handler := NewCartHandler("http://localhost", 0)
+
+	w := httptest.NewRecorder()
+	handler.ConvertCart(w, authRequest("POST", "/api/v1/cart/convert", nil, user.ID))
+
+	if w.Code != http.StatusAccepted {
+		t.Fatalf("convert: want 202, got %d body=%s", w.Code, w.Body.String())
+	}
+
+	var resp struct {
+		Success bool `json:"success"`
+		Data    struct {
+			OrderID     uint   `json:"order_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: %v", err)
+	}
+	if resp.Data.Status != "requires_action" {
+		t.Errorf("status: want requires_action, got %q", resp.Data.Status)
+	}
+	if resp.Data.RedirectURL == "" {
+		t.Error("expected redirect_url in 202 response")
+	}
+
+	db := database.GetDB()
+	var order models.Order
+	if err := db.First(&order, resp.Data.OrderID).Error; err != nil {
+		t.Fatalf("load order: %v", err)
+	}
+	if order.Status != models.OrderStatusRequiresAction {
+		t.Errorf("order status: want requires_action, got %q", order.Status)
+	}
+	if order.StripePaymentID != "pi_sca" {
+		t.Errorf("order stripe_payment_id: want pi_sca, got %q", order.StripePaymentID)
+	}
+
+	var events int64
+	db.Model(&models.OrderEvent{}).
+		Where("order_id = ? AND type = ?", order.ID, audit.EventOrderRequiresAction).
+		Count(&events)
+	if events != 1 {
+		t.Errorf("expected 1 order_requires_action audit event, got %d", events)
+	}
+}
+
 // TestSetCard_ExpiredReturns410 verifies that selecting an already-expired
 // card on the cart returns 410 + CARD_STORAGE_EXPIRED and soft-deletes the
 // card. Exercises cart.go SetCard expired-card branch

api/handlers/ephemeral_test.go

@@ -0,0 +1,341 @@
+package handlers
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"testing"
+
+	"github.com/stripe/stripe-go/v78"
+
+	"terminalShop/pkg/database"
+	"terminalShop/pkg/models"
+)
+
+// seedEphemeralCart seeds an item + address on the user's cart but deliberately
+// NO card — the ephemeral (privacy) path supplies a one-time token at checkout
+// instead of selecting a saved card.
+func seedEphemeralCart(t *testing.T, user models.User) {
+	t.Helper()
+	db := database.GetDB()
+
+	addr := models.Address{
+		UserID: user.ID, Name: "test", Street: "1 Main St",
+		City: "PDX", State: "OR", Zip: "97201", Country: "US",
+	}
+	if err := db.Create(&addr).Error; err != nil {
+		t.Fatalf("seed address: %v", err)
+	}
+	if err := db.Model(&models.Coffee{}).Where("id = ?", 4).Update("price", 500).Error; err != nil {
+		t.Fatalf("pin coffee price: %v", err)
+	}
+
+	h := NewCartHandler("", 0)
+	body, _ := json.Marshal(map[string]any{"coffee_id": 4, "quantity": 2})
+	w := httptest.NewRecorder()
+	h.SetItem(w, authRequest("PUT", "/api/v1/cart/item", body, user.ID))
+	if w.Code != http.StatusOK {
+		t.Fatalf("SetItem: %d %s", w.Code, w.Body.String())
+	}
+	body, _ = json.Marshal(map[string]any{"address_id": addr.ID})
+	w = httptest.NewRecorder()
+	h.SetAddress(w, authRequest("PUT", "/api/v1/cart/address", body, user.ID))
+	if w.Code != http.StatusOK {
+		t.Fatalf("SetAddress: %d %s", w.Code, w.Body.String())
+	}
+}
+
+// TestConvertCart_Ephemeral_InlineSuccess proves the privacy charge path: a
+// one-time PaymentMethod is created from the token, the PaymentIntent attaches
+// NO Customer, the PM is detached after settle, no Card row is written, and the
+// order is paid + marked Ephemeral + keeps the PaymentIntent id (so refunds
+// still work). The table covers both drivers: the per-request flag and the
+// account-level PrivacyMode switch.
+func TestConvertCart_Ephemeral_InlineSuccess(t *testing.T) {
+	cases := []struct {
+		name     string
+		reqEphem bool // request "ephemeral"
+	}{
+		{"per-request flag", true},
+	}
+	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()
+			seedEphemeralCart(t, user)
+
+			var pmNewToken string
+			var piParams *stripe.PaymentIntentParams
+			var detached string
+
+			origNew, origPI, origDetach := paymentMethodNewFn, paymentIntentNewFn, paymentMethodDetachFn
+			defer func() {
+				paymentMethodNewFn, paymentIntentNewFn, paymentMethodDetachFn = origNew, origPI, origDetach
+			}()
+			paymentMethodNewFn = func(p *stripe.PaymentMethodParams) (*stripe.PaymentMethod, error) {
+				if p.Card != nil && p.Card.Token != nil {
+					pmNewToken = *p.Card.Token
+				}
+				return &stripe.PaymentMethod{ID: "pm_once"}, nil
+			}
+			paymentIntentNewFn = func(p *stripe.PaymentIntentParams) (*stripe.PaymentIntent, error) {
+				piParams = p
+				return &stripe.PaymentIntent{ID: "pi_eph", Status: stripe.PaymentIntentStatusSucceeded}, nil
+			}
+			paymentMethodDetachFn = func(id string, _ *stripe.PaymentMethodDetachParams) (*stripe.PaymentMethod, error) {
+				detached = id
+				return &stripe.PaymentMethod{ID: id}, nil
+			}
+
+			body, _ := json.Marshal(map[string]any{"ephemeral": tc.reqEphem, "card_token": "tok_visa"})
+			w := httptest.NewRecorder()
+			NewCartHandler("http://localhost", 0).ConvertCart(w, authRequest("POST", "/api/v1/cart/convert", body, user.ID))
+
+			if w.Code != http.StatusOK {
+				t.Fatalf("convert: want 200, got %d body=%s", w.Code, w.Body.String())
+			}
+			if pmNewToken != "tok_visa" {
+				t.Errorf("one-time PM token: want tok_visa, got %q", pmNewToken)
+			}
+			if piParams == nil {
+				t.Fatal("paymentIntentNewFn was never called")
+			}
+			if piParams.Customer != nil {
+				t.Errorf("ephemeral charge must NOT attach a Customer; got %q", *piParams.Customer)
+			}
+			if piParams.PaymentMethod == nil || *piParams.PaymentMethod != "pm_once" {
+				t.Error("PI must charge the one-time PM pm_once")
+			}
+			if detached != "pm_once" {
+				t.Errorf("PM must be detached after settle; detached=%q", detached)
+			}
+
+			var cardCount int64
+			db.Model(&models.Card{}).Where("user_id = ?", user.ID).Count(&cardCount)
+			if cardCount != 0 {
+				t.Errorf("ephemeral checkout must not save a Card row; found %d", cardCount)
+			}
+
+			var order models.Order
+			if err := db.Where("user_id = ?", user.ID).First(&order).Error; err != nil {
+				t.Fatalf("load order: %v", err)
+			}
+			if !order.Ephemeral {
+				t.Error("order.Ephemeral must be true")
+			}
+			if order.CardID != 0 {
+				t.Errorf("ephemeral order must have CardID 0, got %d", order.CardID)
+			}
+			if order.Status != models.OrderStatusPaid {
+				t.Errorf("status: want paid, got %q", order.Status)
+			}
+			if order.StripePaymentID != "pi_eph" {
+				t.Errorf("order must keep the PaymentIntent id for refunds, got %q", order.StripePaymentID)
+			}
+		})
+	}
+}
+
+// TestConvertCart_Ephemeral_MissingTokenRejected: a privacy checkout with no
+// card token is a 400, and we never reach Stripe.
+func TestConvertCart_Ephemeral_MissingTokenRejected(t *testing.T) {
+	testDB, user := setupCartTestDB(t)
+	defer func() { _ = os.Remove(testDB) }()
+	defer database.ResetForTesting()
+
+	seedEphemeralCart(t, user)
+
+	piCalled := false
+	origPI := paymentIntentNewFn
+	defer func() { paymentIntentNewFn = origPI }()
+	paymentIntentNewFn = func(_ *stripe.PaymentIntentParams) (*stripe.PaymentIntent, error) {
+		piCalled = true
+		return &stripe.PaymentIntent{ID: "pi_x", Status: stripe.PaymentIntentStatusSucceeded}, nil
+	}
+
+	body, _ := json.Marshal(map[string]any{"ephemeral": true}) // no card_token
+	w := httptest.NewRecorder()
+	NewCartHandler("http://localhost", 0).ConvertCart(w, authRequest("POST", "/api/v1/cart/convert", body, user.ID))
+
+	if w.Code != http.StatusBadRequest {
+		t.Fatalf("want 400, got %d body=%s", w.Code, w.Body.String())
+	}
+	if piCalled {
+		t.Error("must not create a PaymentIntent when the card token is missing")
+	}
+}
+
+// TestConvertCart_Ephemeral_RequiresActionDefersDetach: on a 3DS challenge the
+// charge has not settled, so the PM must stay attached (the webhook detaches it
+// later). The order persists Ephemeral so the webhook knows to detach.
+func TestConvertCart_Ephemeral_RequiresActionDefersDetach(t *testing.T) {
+	testDB, user := setupCartTestDB(t)
+	defer func() { _ = os.Remove(testDB) }()
+	defer database.ResetForTesting()
+
+	seedEphemeralCart(t, user)
+
+	detachCalled := false
+	origNew, origPI, origDetach := paymentMethodNewFn, paymentIntentNewFn, paymentMethodDetachFn
+	defer func() {
+		paymentMethodNewFn, paymentIntentNewFn, paymentMethodDetachFn = origNew, origPI, origDetach
+	}()
+	paymentMethodNewFn = func(_ *stripe.PaymentMethodParams) (*stripe.PaymentMethod, error) {
+		return &stripe.PaymentMethod{ID: "pm_once_3ds"}, nil
+	}
+	paymentIntentNewFn = func(_ *stripe.PaymentIntentParams) (*stripe.PaymentIntent, error) {
+		return &stripe.PaymentIntent{
+			ID:     "pi_eph_3ds",
+			Status: stripe.PaymentIntentStatusRequiresAction,
+			NextAction: &stripe.PaymentIntentNextAction{
+				RedirectToURL: &stripe.PaymentIntentNextActionRedirectToURL{URL: "https://hooks.stripe.com/3ds/test"},
+			},
+		}, nil
+	}
+	paymentMethodDetachFn = func(id string, _ *stripe.PaymentMethodDetachParams) (*stripe.PaymentMethod, error) {
+		detachCalled = true
+		return &stripe.PaymentMethod{ID: id}, nil
+	}
+
+	body, _ := json.Marshal(map[string]any{"ephemeral": true, "card_token": "tok_3ds"})
+	w := httptest.NewRecorder()
+	NewCartHandler("http://localhost", 0).ConvertCart(w, authRequest("POST", "/api/v1/cart/convert", body, user.ID))
+
+	if w.Code != http.StatusAccepted {
+		t.Fatalf("want 202, got %d body=%s", w.Code, w.Body.String())
+	}
+	if detachCalled {
+		t.Error("must NOT detach the PM while 3DS is pending; the webhook owns the deferred detach")
+	}
+
+	var order models.Order
+	if err := database.GetDB().Where("user_id = ?", user.ID).First(&order).Error; err != nil {
+		t.Fatalf("load order: %v", err)
+	}
+	if !order.Ephemeral {
+		t.Error("order.Ephemeral must persist so the webhook can detach later")
+	}
+	if order.Status != models.OrderStatusRequiresAction {
+		t.Errorf("status: want requires_action, got %q", order.Status)
+	}
+}
+
+// TestHandlePaymentIntentSucceeded_EphemeralDetach exercises the deferred (3DS)
+// detach: an Ephemeral order finishing via webhook detaches its PM; a
+// non-ephemeral one does not.
+func TestHandlePaymentIntentSucceeded_EphemeralDetach(t *testing.T) {
+	cases := []struct {
+		name       string
+		ephemeral  bool
+		wantDetach string // expected detached PM id, "" if none
+	}{
+		{"ephemeral order detaches PM", true, "pm_eph_once"},
+		{"non-ephemeral order keeps PM", false, ""},
+	}
+	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()
+			order := models.Order{
+				UserID: user.ID, CardID: 0, Ephemeral: tc.ephemeral,
+				StripePaymentID: "pi_eph_webhook", 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)
+			}
+
+			detached := ""
+			origDetach := paymentMethodDetachFn
+			defer func() { paymentMethodDetachFn = origDetach }()
+			paymentMethodDetachFn = func(id string, _ *stripe.PaymentMethodDetachParams) (*stripe.PaymentMethod, error) {
+				detached = id
+				return &stripe.PaymentMethod{ID: id}, nil
+			}
+
+			pi := map[string]any{
+				"id":             order.StripePaymentID,
+				"amount":         order.Total,
+				"currency":       "usd",
+				"payment_method": "pm_eph_once",
+				"metadata":       map[string]string{"order_id": fmt.Sprintf("%d", order.ID)},
+			}
+			raw, _ := json.Marshal(pi)
+			evt := stripe.Event{Type: "payment_intent.succeeded", Data: &stripe.EventData{Raw: raw}}
+
+			NewWebhookHandler("", "").handlePaymentIntentSucceeded(context.Background(), evt)
+
+			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 paid, got %q", reloaded.Status)
+			}
+			if detached != tc.wantDetach {
+				t.Errorf("detach: want %q, got %q", tc.wantDetach, detached)
+			}
+		})
+	}
+}
+
+// TestConvertCart_PrivacyModeSoftDefault proves PrivacyMode is NOT enforced
+// server-side: a user with privacy_mode on who explicitly checks out a saved
+// card (ephemeral=false) gets the normal kept-card charge — Customer attached,
+// PM not detached, order not Ephemeral. This is what makes "save anyway" work.
+func TestConvertCart_PrivacyModeSoftDefault(t *testing.T) {
+	testDB, user := setupCartTestDB(t)
+	defer func() { _ = os.Remove(testDB) }()
+	defer database.ResetForTesting()
+
+	db := database.GetDB()
+	if err := db.Model(&user).Update("privacy_mode", true).Error; err != nil {
+		t.Fatalf("set privacy_mode: %v", err)
+	}
+	seedConvertReadyCart(t, user) // seeds a SAVED card + address + item
+
+	var piParams *stripe.PaymentIntentParams
+	detachCalled := false
+	origPI, origDetach := paymentIntentNewFn, paymentMethodDetachFn
+	defer func() { paymentIntentNewFn, paymentMethodDetachFn = origPI, origDetach }()
+	paymentIntentNewFn = func(p *stripe.PaymentIntentParams) (*stripe.PaymentIntent, error) {
+		piParams = p
+		return &stripe.PaymentIntent{ID: "pi_kept", Status: stripe.PaymentIntentStatusSucceeded}, nil
+	}
+	paymentMethodDetachFn = func(id string, _ *stripe.PaymentMethodDetachParams) (*stripe.PaymentMethod, error) {
+		detachCalled = true
+		return &stripe.PaymentMethod{ID: id}, nil
+	}
+
+	body, _ := json.Marshal(map[string]any{"ephemeral": false})
+	w := httptest.NewRecorder()
+	NewCartHandler("http://localhost", 0).ConvertCart(w, authRequest("POST", "/api/v1/cart/convert", body, user.ID))
+
+	if w.Code != http.StatusOK {
+		t.Fatalf("convert: want 200, got %d body=%s", w.Code, w.Body.String())
+	}
+	if piParams == nil || piParams.Customer == nil {
+		t.Error("saved-card path must attach a Customer even when privacy_mode is on")
+	}
+	if detachCalled {
+		t.Error("must NOT detach a saved card")
+	}
+	var order models.Order
+	if err := db.Where("user_id = ?", user.ID).First(&order).Error; err != nil {
+		t.Fatalf("load order: %v", err)
+	}
+	if order.Ephemeral {
+		t.Error("explicit ephemeral=false must win over privacy_mode (soft default)")
+	}
+}

api/handlers/webhook.go

@@ -180,6 +180,13 @@ func (h *WebhookHandler) handlePaymentIntentSucceeded(ctx context.Context, event
 		}
 	}
 
+	if order.Ephemeral && pi.PaymentMethod != nil && pi.PaymentMethod.ID != "" {
+		if _, derr := paymentMethodDetachFn(pi.PaymentMethod.ID, nil); derr != nil {
+			webhookLog().Warn("failed to detach ephemeral payment method",
+				"order_id", order.ID, "pi", pi.ID, "error", derr)
+		}
+	}
+
 	audit.OrderPaid(order.UserID, order.ID, int(pi.Amount), pi.ID)
 	go notify.SlackOrderPaid(&order)
 	webhookLog().Info("order marked paid", "order_id", orderIDStr, "pi", pi.ID)

api/main_test.go

@@ -0,0 +1,92 @@
+package main
+
+import (
+	"context"
+	"testing"
+	"time"
+)
+
+// TestEveryTick_CallsFnOnTick verifies the helper invokes fn repeatedly on its
+// interval. A non-blocking send keeps the spawned goroutine from ever blocking
+// on a full channel, and the 1s timeout per tick is generous vs the 1ms
+// interval so the test is not timing-flaky.
+func TestEveryTick_CallsFnOnTick(t *testing.T) {
+	ctx := t.Context()
+
+	fired := make(chan struct{}, 1)
+	everyTick(ctx, time.Millisecond, func(context.Context) {
+		select {
+		case fired <- struct{}{}:
+		default:
+		}
+	})
+
+	for i := range 3 {
+		select {
+		case <-fired:
+		case <-time.After(time.Second):
+			t.Fatalf("tick %d did not fire within 1s", i+1)
+		}
+	}
+}
+
+// TestEveryTick_StopsOnContextCancel verifies cancelling ctx stops the loop.
+// After the first tick we cancel inside the inter-tick gap, so everyTick's
+// select sees only ctx.Done ready (ticker.C is cold) and returns
+// deterministically — there is no random pick between two ready cases. We then
+// confirm no further tick arrives within a full interval, which a live loop
+// could not satisfy. This is the shutdown guarantee the reconcilers depend on.
+func TestEveryTick_StopsOnContextCancel(t *testing.T) {
+	ctx, cancel := context.WithCancel(context.Background())
+
+	const interval = 50 * time.Millisecond
+	ticks := make(chan struct{}) // unbuffered: fn blocks until the test receives
+	everyTick(ctx, interval, func(context.Context) {
+		ticks <- struct{}{}
+	})
+
+	// First tick proves the loop is running and leaves the goroutine back in
+	// select with ticker.C cold for the next ~interval.
+	select {
+	case <-ticks:
+	case <-time.After(time.Second):
+		t.Fatal("everyTick never called fn")
+	}
+
+	cancel()
+
+	// Cancel landed in the cold gap, so the loop must have taken ctx.Done and
+	// returned. A live loop would tick again at ~interval; a stopped one never
+	// will.
+	select {
+	case <-ticks:
+		t.Fatal("everyTick ticked again after cancel")
+	case <-time.After(interval + 50*time.Millisecond):
+		// good: silent past a full interval — the loop returned
+	}
+}
+
+func TestEveryTick_PassesContextToFn(t *testing.T) {
+	type ctxKey string
+	const marker ctxKey = "marker"
+	ctx, cancel := context.WithCancel(context.WithValue(context.Background(), marker, "present"))
+	defer cancel()
+
+	got := make(chan string, 1)
+	everyTick(ctx, time.Millisecond, func(c context.Context) {
+		v, _ := c.Value(marker).(string)
+		select {
+		case got <- v:
+		default:
+		}
+	})
+
+	select {
+	case v := <-got:
+		if v != "present" {
+			t.Fatalf("fn received wrong context: value = %q, want %q", v, "present")
+		}
+	case <-time.After(time.Second):
+		t.Fatalf("fn never ran")
+	}
+}

api/routes/routes.go

@@ -53,6 +53,8 @@ func SetupRoutes(
 	viewHandler := handlers.NewViewHandler()
 	webhookHandler := handlers.NewWebhookHandler(stripeWebhookSecret, shippoWebhookSecret)
 	slackHandler := handlers.NewSlackHandler(slackSigningSecret, adminAPIKey, apiPort, shippoWebhookSecret)
+	adminUserHandler := handlers.NewAdminUserHandler()
+	accountHandler := handlers.NewAccountHandler(maxOrderCents)
 
 	// Short payment redirect and success page — no auth required.
 	r.Get("/pay/{token}", handlers.PayRedirect)
@@ -104,6 +106,12 @@ func SetupRoutes(
 
 			r.Get("/view/init", viewHandler.GetViewInit)
 
+			// Account self-service settings, JWT-authed, edits the callers
+			// own row (user id from context, never a URL param). Distinct from
+			// the admin /users/{id}/order-cap setter in the RequireAdmin group.
+			r.Put("/account/spend-limit", accountHandler.SetSpendLimit)
+			r.Put("/account/privacy-mode", accountHandler.SetPrivacyMode)
+
 			// Cart
 			r.Route("/cart", func(r chi.Router) {
 				r.Get("/", cartHandler.GetCart)
@@ -149,6 +157,8 @@ func SetupRoutes(
 			r.Use(middleware.RequireAdmin)
 			r.Patch("/orders/{id}/tracking", orderHandler.UpdateTracking)
 			r.Post("/orders/{id}/label", orderHandler.PurchaseLabel)
+			// Set or clear a user's per-user order spend-cap override.
+			r.Patch("/users/{id}/order-cap", adminUserHandler.SetUserOrderCap)
 		})
 	})
 

pkg/api/client.go

@@ -453,6 +453,77 @@ func (c *Client) SetCartCard(cardID uint) error {
 	return nil
 }
 
+func (c *Client) SetSpendLimit(cents *int) error {
+	url := fmt.Sprintf("%s/api/v1/account/spend-limit", c.BaseURL)
+
+	body := map[string]any{
+		"self_limit_cents": cents,
+	}
+	jsonData, err := json.Marshal(body)
+	if err != nil {
+		return fmt.Errorf("failed to marshal request: %w", err)
+	}
+
+	req, err := http.NewRequest("PUT", url, bytes.NewBuffer(jsonData))
+	if err != nil {
+		return fmt.Errorf("failed to create request: %w", err)
+	}
+	req.Header.Set("Content-Type", "application/json")
+
+	resp, err := c.doRequest(req)
+	if err != nil {
+		return fmt.Errorf("failed to set spend limit: %w", err)
+	}
+	defer func() { _ = resp.Body.Close() }()
+
+	var result APIResponse
+	if err := json.NewDecoder(resp.Body).Decode(&result); err != nil {
+		return fmt.Errorf("failed to decode response: %w", err)
+	}
+
+	if !result.Success {
+		if result.Error != nil {
+			return fmt.Errorf("%s: %s", result.Error.Code, result.Error.Message)
+		}
+		return fmt.Errorf("failed to set spend limit")
+	}
+
+	return nil
+}
+
+// SetPrivacyMode sets the users account-level privacy default ("keep as little
+// as possible"). A soft default the checkout can override per order.
+func (c *Client) SetPrivacyMode(on bool) error {
+	url := fmt.Sprintf("%s/api/v1/account/privacy-mode", c.BaseURL)
+
+	jsonData, err := json.Marshal(map[string]any{"privacy_mode": on})
+	if err != nil {
+		return fmt.Errorf("failed to marshal request: %w", err)
+	}
+	req, err := http.NewRequest("PUT", url, bytes.NewReader(jsonData))
+	if err != nil {
+		return fmt.Errorf("failed to create request: %w", err)
+	}
+	req.Header.Set("Content-Type", "application/json")
+
+	resp, err := c.doRequest(req)
+	if err != nil {
+		return fmt.Errorf("failed to set privacy mode: %w", err)
+	}
+	defer func() { _ = resp.Body.Close() }()
+
+	var result APIResponse
+	if err := json.NewDecoder(resp.Body).Decode(&result); err != nil {
+		return fmt.Errorf("failed to decode response: %w", err)
+	}
+	if !result.Success {
+		if result.Error != nil {
+			return fmt.Errorf("%s: %s", result.Error.Code, result.Error.Message)
+		}
+	}
+	return nil
+}
+
 // ClearCart removes all items from the user's cart.
 func (c *Client) ClearCart() error {
 	url := fmt.Sprintf("%s/api/v1/cart", c.BaseURL)
@@ -487,9 +558,38 @@ func (c *Client) ClearCart() error {
 // Returns a CheckoutOutcome that either carries the completed Order or
 // indicates the customer must complete 3DS authentication via RedirectURL.
 func (c *Client) ConvertCart() (*CheckoutOutcome, error) {
+	return c.convertCart(nil)
+}
+
+// ConvertCartEphemeral converts the cart in privacy mode: it charges a one-time
+// card (cardToken) that is never saved and is detached after the charge settles.
+// Used when the customer leaves "save this card" unchecked at checkout.
+func (c *Client) ConvertCartEphemeral(cardToken string) (*CheckoutOutcome, error) {
+	jsonData, err := json.Marshal(map[string]any{
+		"ephemeral":  true,
+		"card_token": cardToken,
+	})
+	if err != nil {
+		return nil, fmt.Errorf("failed to marshal request: %w", err)
+	}
+	return c.convertCart(jsonData)
+}
+
+// convertCart POSTs to /cart/convert with an optional JSON body (nil = saved-card
+// flow) parses the shared response into a CheckoutOutcome.
+func (c *Client) convertCart(jsonData []byte) (*CheckoutOutcome, error) {
 	url := fmt.Sprintf("%s/api/v1/cart/convert", c.BaseURL)
 
-	req, err := http.NewRequest("POST", url, nil)
+	var req *http.Request
+	var err error
+	if jsonData != nil {
+		req, err = http.NewRequest("POST", url, bytes.NewBuffer(jsonData))
+		if err == nil {
+			req.Header.Set("Content-Type", "application/json")
+		}
+	} else {
+		req, err = http.NewRequest("POST", url, nil)
+	}
 	if err != nil {
 		return nil, fmt.Errorf("failed to create request: %w", err)
 	}

pkg/audit/audit.go

@@ -50,6 +50,9 @@ const (
 	eventTrackingUpdated        eventType = "tracking_updated"
 	eventOrderDelivered         eventType = "order_delivered"
 	eventTrackingMarkedManually eventType = "tracking_marked_manually"
+	eventUserOrderCapSet        eventType = "user_order_cap_set"
+	eventUserSelfLimitSet       eventType = "user_self_limit_set"
+	eventUserPrivacyModeSet     eventType = "user_privacy_mode_set"
 )
 
 type event struct {
@@ -380,3 +383,64 @@ func CartRejected(userID uint, totalCents, capCents int) {
 	}
 	slog.Info("audit", e.attrs()...)
 }
+
+// UserOrderCapSet records an operator changing a user's per-user order-spend
+// cap override (User.MaxOrderCents), an admin-gated action. A nil capCents means
+// the override was cleared and the user reverts to the global MAX_ORDER_CENTS;
+// Status distinguishes "set" from "cleared" so a cap set to 0 (off-switch, which
+// attrs() omits because cap_cents == 0) is still legible in the log.
+func UserOrderCapSet(actor string, userID uint, capCents *int) {
+	e := event{
+		Event:  eventUserOrderCapSet,
+		Actor:  actor,
+		UserID: userID,
+	}
+	if capCents == nil {
+		e.Status = "cleared"
+	} else {
+		e.Status = "set"
+		e.CapCents = *capCents
+	}
+	slog.Info("audit", e.attrs()...)
+}
+
+// UserSelfLimitSet records a customer changing their own self-service spend
+// limit (User.SelfLimitCents) via the JWT-authed account endpoint. Kept
+// deliberately distinct from UserOrderCapSet (the operator's admin-gated
+// override) so the customer action and the operator action are never conflated
+// in the audit trail. A nil capCents means the self-limit was cleared (the user
+// reverts to the admin/global cap). Unlike the admin cap, an explicit 0 here is
+// a real "block everything" ceiling, not an off-switch, so Status distinguishes
+// "set" from "cleared" and a cap of 0 (which attrs() omits) stays legible.
+func UserSelfLimitSet(userID uint, capCents *int) {
+	e := event{
+		Event:  eventUserSelfLimitSet,
+		Actor:  "self",
+		UserID: userID,
+	}
+	if capCents == nil {
+		e.Status = "cleared"
+	} else {
+		e.Status = "set"
+		e.CapCents = *capCents
+	}
+	slog.Info("audit", e.attrs()...)
+}
+
+// UserPrivacyModeSet records a customer toggling their account-level privacy
+// ("keep as little as possible") default via the JWT-authed account endpoint.
+// Actor "self" mirrors UserSelfLimitSet; Status carries the new state so the
+// trail reads cleanly without a dedicated column.
+func UserPrivacyModeSet(userID uint, enabled bool) {
+	e := event{
+		Event:  eventUserPrivacyModeSet,
+		Actor:  "self",
+		UserID: userID,
+	}
+	if enabled {
+		e.Status = "enabled"
+	} else {
+		e.Status = "disabled"
+	}
+	slog.Info("audit", e.attrs()...)
+}

pkg/config/config.go

@@ -138,11 +138,14 @@ func getEnvOrDefault(key, defaultValue string) string {
 	return defaultValue
 }
 
-// loadMaxOrderCents reads MAX_ORDER_CENTS. Default $500 — aligns with the
-// PSD2 TRA exemption ceiling (above this, Stripe always requests SCA, so the
-// cap is only meaningful below it). Explicit 0 disables the cap. Garbage or
-// negative values fall back to the default with a warning so an operator
-// typo cannot silently disable a fraud control.
+// loadMaxOrderCents reads MAX_ORDER_CENTS. Default $500 — roughly tracks the
+// PSD2 TRA exemption ceiling of €500 (≈ $540, FX-dependent), above which Stripe
+// always requests SCA, so the cap is only meaningful below it. We charge in USD
+// and the regulatory ceiling is in EUR, so this is an approximate anchor, not an
+// exact equivalence — $500 trips slightly below the true ceiling, which is the
+// safe direction. Explicit 0 disables the cap. Garbage or negative values fall
+// back to the default with a warning so an operator typo cannot silently disable
+// a fraud control.
 func loadMaxOrderCents() int {
 	const defaultCap = 50000
 	raw := os.Getenv("MAX_ORDER_CENTS")

pkg/models/coffee.go

@@ -33,6 +33,8 @@ var AccountMenuItems = []string{
 	"order history",
 	"addresses",
 	"cards",
+	"spend limit",
+	"privacy",
 	"faq",
 	"about",
 }

pkg/models/order.go

@@ -37,6 +37,7 @@ type Order struct {
 	UserID          uint        `gorm:"not null;index" json:"user_id"`
 	CardID          uint        `gorm:"not null" json:"card_id"`
 	StripePaymentID string      `gorm:"size:255" json:"-"` // Stripe PaymentIntent ID
+	Ephemeral       bool        `gorm:"default:false" json:"ephemeral"`
 	Status          OrderStatus `gorm:"size:50;not null;default:'pending'" json:"status"`
 	Subtotal        int         `gorm:"not null" json:"subtotal"`         // Amount in cents
 	ShippingCost    int         `gorm:"default:0" json:"shipping_cost"`   // Amount in cents

pkg/models/user.go

@@ -9,16 +9,26 @@ import (
 // User represents a user authenticated via SSH public key
 // No passwords - SSH key is the ONLY authentication method (matches terminal.shop exactly)
 type User struct {
-	ID                uint           `gorm:"primaryKey" json:"id"`
-	SSHKeyFingerprint string         `gorm:"uniqueIndex;size:100;not null" json:"ssh_key_fingerprint"` // SHA256 fingerprint - PRIMARY identifier
-	SSHPublicKey      string         `gorm:"uniqueIndex;type:text;not null" json:"-"`                  // Full SSH public key
-	Name              string         `gorm:"size:255" json:"name,omitempty"`                           // Real name (for shipping labels)
-	Email             string         `gorm:"size:255" json:"email,omitempty"`                          // Email (for receipts)
-	Anonymous         bool           `gorm:"default:false" json:"anonymous"`                           // True if connected without SSH key
-	StripeCustomerID  string         `gorm:"size:255" json:"-"`
-	CreatedAt         time.Time      `json:"created_at"`
-	UpdatedAt         time.Time      `json:"updated_at"`
-	DeletedAt         gorm.DeletedAt `gorm:"index" json:"-"`
+	ID                uint   `gorm:"primaryKey" json:"id"`
+	SSHKeyFingerprint string `gorm:"uniqueIndex;size:100;not null" json:"ssh_key_fingerprint"` // SHA256 fingerprint - PRIMARY identifier
+	SSHPublicKey      string `gorm:"uniqueIndex;type:text;not null" json:"-"`                  // Full SSH public key
+	Name              string `gorm:"size:255" json:"name,omitempty"`                           // Real name (for shipping labels)
+	Email             string `gorm:"size:255" json:"email,omitempty"`                          // Email (for receipts)
+	Anonymous         bool   `gorm:"default:false" json:"anonymous"`                           // True if connected without SSH key
+	StripeCustomerID  string `gorm:"size:255" json:"-"`
+	PrivacyMode       bool   `gorm:"default:false" json:"privacy_mode"`
+	// MaxOrderCents is an optional per-user override of the global MAX_ORDER_CENTS
+	// spend cap. It may raise OR lower the global cap — both directions are
+	// intentional (e.g. a vetted corporate buyer gets a higher ceiling; a flagged
+	// account gets a lower one). States: nil = inherit the global; explicit 0 =
+	// per-user off-switch (same semantics as the global); >0 = custom ceiling. A
+	// negative value is treated as "no override" (falls back to global) with a
+	// warning — see ConvertCart. Operator-set out-of-band; kept out of API payloads.
+	MaxOrderCents  *int           `json:"-"`
+	SelfLimitCents *int           `json:"self_limit_cents,omitempty"`
+	CreatedAt      time.Time      `json:"created_at"`
+	UpdatedAt      time.Time      `json:"updated_at"`
+	DeletedAt      gorm.DeletedAt `gorm:"index" json:"-"`
 }
 
 // TableName specifies the table name for the User model
@@ -32,6 +42,8 @@ type PublicUser struct {
 	SSHKeyFingerprint string    `json:"ssh_key_fingerprint"`
 	Name              string    `json:"name,omitempty"`
 	Email             string    `json:"email,omitempty"`
+	SelfLimitCents    *int      `json:"self_limit_cents,omitempty"`
+	PrivacyMode       bool      `json:"privacy_mode"`
 	CreatedAt         time.Time `json:"created_at"`
 }
 
@@ -42,6 +54,8 @@ func (u *User) ToPublic() PublicUser {
 		SSHKeyFingerprint: u.SSHKeyFingerprint,
 		Name:              u.Name,
 		Email:             u.Email,
+		SelfLimitCents:    u.SelfLimitCents,
+		PrivacyMode:       u.PrivacyMode,
 		CreatedAt:         u.CreatedAt,
 	}
 }

pkg/models/user_test.go

@@ -0,0 +1,15 @@
+package models
+
+import "testing"
+
+// TestToPublic_IncludesPrivacyMode guards the converter: PublicUser must carry
+// the user's PrivacyMode so the TUI can reflect the account toggle's real state.
+// (Regression: ToPublic originally omitted this field and always reported false.)
+func TestToPublic_IncludesPrivacyMode(t *testing.T) {
+	for _, want := range []bool{true, false} {
+		u := User{ID: 1, PrivacyMode: want}
+		if got := u.ToPublic().PrivacyMode; got != want {
+			t.Errorf("ToPublic().PrivacyMode = %v, want %v", got, want)
+		}
+	}
+}

pkg/tui/account.go

@@ -1,8 +1,11 @@
 package tui
 
 import (
+	"fmt"
+	"strconv"
 	"strings"
 
+	"charm.land/bubbles/v2/textinput"
 	"charm.land/bubbles/v2/viewport"
 	tea "charm.land/bubbletea/v2"
 	"charm.land/lipgloss/v2"
@@ -19,9 +22,7 @@ func (m Model) accountBodyHeight() int {
 	footerHeight := lipgloss.Height(m.BuildFooter())
 	budget := m.heightContainer - headerHeight - footerHeight - 2
 	cards := budget / orderCardHeight
-	if cards < 1 {
-		cards = 1
-	}
+	cards = max(cards, 1)
 	return cards*orderCardHeight - 2
 }
 
@@ -82,6 +83,10 @@ func (m Model) getAccountDetailContent() string {
 		return m.AddressesView(detailContentWidth)
 	case "cards":
 		return m.CardsView(detailContentWidth)
+	case "spend limit":
+		return m.SpendLimitView(detailContentWidth)
+	case "privacy":
+		return m.PrivacyView(detailContentWidth)
 	case "faq":
 		questionStyle := m.theme.TextHighlight().Bold(true)
 		contentStyle := m.theme.TextBody().Width(detailContentWidth)
@@ -170,7 +175,7 @@ func (m Model) BuildAccountView() string {
 	// the menu, and falls back to the gray pill when focus has moved into the
 	// detail area (browsing orders, managing addresses/cards, scrolling faq).
 	focusedInside := m.account.orderViewState > 0 || m.account.addressListFocused ||
-		m.account.cardListFocused || m.account.faqFocused
+		m.account.cardListFocused || m.account.faqFocused || m.account.spendLimitFocused
 	pillBg := m.theme.Highlight()
 	if focusedInside {
 		pillBg = cPill
@@ -257,6 +262,43 @@ func (m Model) AboutView(width int) string {
 }
 
 func (m Model) AccountUpdate(msg tea.Msg) (Model, tea.Cmd) {
+	// Async result of a spend-limit save (delivered here because the account
+	// page is active when the command resolves).
+	if saved, ok := msg.(spendLimitSavedMsg); ok {
+		m.account.spendLimitSaving = false
+		if saved.Err != nil {
+			m.account.spendLimitErr = friendlySpendLimitError(saved.Err)
+			return m, nil
+		}
+		if m.User != nil {
+			m.User.SelfLimitCents = saved.Cents
+		}
+		m.account.spendLimitFocused = false
+		m.account.spendLimitInput.Blur()
+		m.account.spendLimitErr = ""
+		m.footer = defaultAccountFooter()
+		m.notice = &VisibleNotice{message: "Spend limit updated"}
+		return m, nil
+	}
+
+	if saved, ok := msg.(privacyModeSavedMsg); ok {
+		m.account.privacyModeSaving = false
+		if saved.Err != nil {
+			m.account.privacyModeErr = saved.Err.Error()
+			return m, nil
+		}
+		if m.User != nil {
+			m.User.PrivacyMode = saved.Enabled
+		}
+		m.account.privacyModeErr = ""
+		state := "off"
+		if saved.Enabled {
+			state = "on"
+		}
+		m.notice = &VisibleNotice{message: "Privacy mode " + state}
+		return m, nil
+	}
+
 	keyMsg, ok := msg.(tea.KeyMsg)
 	if !ok {
 		// Pass non-key messages to viewport (e.g. window resize)
@@ -265,6 +307,24 @@ func (m Model) AccountUpdate(msg tea.Msg) (Model, tea.Cmd) {
 		return m, cmd
 	}
 
+	// While the spend-limit input is focused it owns the keyboard: enter saves,
+	// esc cancels, everything else edits the field.
+	if m.account.spendLimitFocused {
+		switch keyMsg.String() {
+		case "esc":
+			m.account.spendLimitFocused = false
+			m.account.spendLimitInput.Blur()
+			m.account.spendLimitErr = ""
+			m.footer = defaultAccountFooter()
+			return m, nil
+		case "enter":
+			return m.submitSpendLimit()
+		}
+		var cmd tea.Cmd
+		m.account.spendLimitInput, cmd = m.account.spendLimitInput.Update(msg)
+		return m, cmd
+	}
+
 	selectedItem := ""
 	if m.account.cursor < len(models.AccountMenuItems) {
 		selectedItem = models.AccountMenuItems[m.account.cursor]
@@ -423,6 +483,28 @@ func (m Model) AccountUpdate(msg tea.Msg) (Model, tea.Cmd) {
 					{key: "esc", value: "back"},
 				}
 			}
+		case "spend limit":
+			if !m.account.spendLimitFocused {
+				ti := textinput.New()
+				ti.Prompt = "$"
+				ti.Placeholder = "dollars (blank = no limit)"
+				ti.CharLimit = 12
+				// Prefill with the current limit so the user edits rather than retypes.
+				if m.User != nil && m.User.SelfLimitCents != nil {
+					ti.SetValue(formatCentsDollars(*m.User.SelfLimitCents))
+				}
+				cmd := ti.Focus()
+				m.account.spendLimitInput = ti
+				m.account.spendLimitFocused = true
+				m.account.spendLimitErr = ""
+				m.footer = []footerCommand{
+					{key: "enter", value: "save"},
+					{key: "esc", value: "cancel"},
+				}
+				return m, cmd
+			}
+		case "privacy":
+			return m.togglePrivacyMode()
 		case "faq":
 			if !m.account.faqFocused {
 				m.account.faqFocused = true
@@ -438,14 +520,7 @@ func (m Model) AccountUpdate(msg tea.Msg) (Model, tea.Cmd) {
 		}
 
 	case "esc":
-		accountDefaultFooter := []footerCommand{
-			{key: "j/k", value: "navigate"},
-			{key: "enter", value: "select"},
-			{key: "s", value: "shop"},
-			{key: "c", value: "cart"},
-			{key: "?", value: "help"},
-			{key: "q", value: "quit"},
-		}
+		accountDefaultFooter := defaultAccountFooter()
 		if m.account.addressDeleting != nil {
 			m.account.addressDeleting = nil
 		} else if m.account.addressListFocused {
@@ -485,3 +560,240 @@ func (m Model) AccountUpdate(msg tea.Msg) (Model, tea.Cmd) {
 	}
 	return m, nil
 }
+
+// spendLimitSavedMsg carries the result of an async SetSpendLimit call back to
+// AccountUpdate. Cents is the value that was sent (echoed so the view can update
+// without a refetch); Err is non-nil when the save failed.
+type spendLimitSavedMsg struct {
+	Cents *int
+	Err   error
+}
+
+// SpendLimitView renders the self-service spend-limit panel: the current limit,
+// and — when focused — the editable input. Layout follows the label/box idiom
+// used by the refund composer (pkg/tui/refund.go).
+func (m Model) SpendLimitView(width int) string {
+	labelStyle := m.theme.TextLabel()
+	bodyStyle := m.theme.TextBody().Width(width)
+	hintStyle := m.theme.TextDim()
+
+	current := "no limit set"
+	if m.User != nil && m.User.SelfLimitCents != nil {
+		current = "$" + formatCentsDollars(*m.User.SelfLimitCents)
+	}
+
+	out := bodyStyle.Render(wordWrap(
+		"Set your own spending limit. It can only lower the cap on your account, never raise it. Leave blank to remove your limit; 0 blocks all orders.",
+		width,
+	)) + "\n\n"
+	out += labelStyle.Render("Current limit") + "\n"
+	out += m.theme.TextAccent().Render(current) + "\n\n"
+
+	if !m.account.spendLimitFocused {
+		return out + hintStyle.Render("enter: edit limit")
+	}
+
+	box := lipgloss.NewStyle().
+		Border(lipgloss.RoundedBorder()).
+		BorderForeground(m.theme.Highlight()).
+		Width(max(1, width-2))
+	m.account.spendLimitInput.SetWidth(max(1, width-3))
+	out += labelStyle.Render("New limit (dollars)") + "\n"
+	out += box.Render(m.account.spendLimitInput.View())
+	switch {
+	case m.account.spendLimitSaving:
+		out += "\n" + m.theme.TextAccent().Render("saving...")
+	case m.account.spendLimitErr != "":
+		out += "\n" + m.theme.TextError().Render(m.account.spendLimitErr)
+	}
+	out += "\n" + hintStyle.Render("enter: save · esc: cancel")
+	return out
+}
+
+// submitSpendLimit validates the input and, if valid, fires the save command.
+// Validation mirrors the server's write-boundary rules so the user gets instant
+// feedback for the negative/non-numeric cases before any round-trip.
+func (m Model) submitSpendLimit() (Model, tea.Cmd) {
+	cents, err := parseSpendLimitInput(m.account.spendLimitInput.Value())
+	if err != nil {
+		m.account.spendLimitErr = err.Error()
+		return m, nil
+	}
+	m.account.spendLimitErr = ""
+	m.account.spendLimitSaving = true
+	return m, m.setSpendLimitCmd(cents)
+}
+
+// setSpendLimitCmd calls the API off the UI thread and reports back via
+// spendLimitSavedMsg. Mirrors the command shape of createRefundRequestCmd.
+func (m Model) setSpendLimitCmd(cents *int) tea.Cmd {
+	return func() tea.Msg {
+		if m.APIClient == nil || m.User == nil {
+			return spendLimitSavedMsg{Err: fmt.Errorf("not authenticated")}
+		}
+		err := m.APIClient.SetSpendLimit(cents)
+		return spendLimitSavedMsg{Cents: cents, Err: err}
+	}
+}
+
+// privacyModeSavedMsg carries the result of an async SetPrivacyMode call back to
+// AccountUpdate. Enabled echoes the value sent so the view updates without a
+// refetch; Err is non-nil when the save failed.
+type privacyModeSavedMsg struct {
+	Enabled bool
+	Err     error
+}
+
+// PrivacyView renders the account-level privacy toggle ("keep as little as
+// possible"). A soft default: the checkout can still override it per order.
+func (m Model) PrivacyView(width int) string {
+	labelStyle := m.theme.TextLabel()
+	bodyStyle := m.theme.TextBody().Width(width)
+	hintStyle := m.theme.TextDim()
+
+	state := "off"
+	if m.User != nil && m.User.PrivacyMode {
+		state = "on"
+	}
+
+	// Privacy copy is split into short labelled sections instead of one wall of
+	// text, reusing the same labelStyle/bodyStyle pairing as the rest of the
+	// account view so it reads as scannable blocks.
+	sections := []struct{ title, body string }{
+		{
+			"Philosophy",
+			"Regardless of privacy mode, I never keep your full card number. Full stop.",
+		},
+		{
+			"Privacy disabled",
+			"Only the last 4 digits, card brand and a payment token is stored",
+		},
+		{
+			"Privacy enabled",
+			"With privacy mode ENABLED checkout uses a one-time card. All of the data is wiped the millisecond you pay",
+		},
+		{
+			"Your address",
+			"This one I have to keep. The law makes me, sometimes for years. So I store it offline, on my own network, where only I can reach it. Sorry about that.",
+		},
+	}
+
+	out := bodyStyle.Render(wordWrap("", width))
+	for _, s := range sections {
+		out += labelStyle.Render(s.title) + "\n"
+		out += bodyStyle.Render(wordWrap(s.body, width)) + "\n\n"
+	}
+	out += labelStyle.Render("Privacy mode") + "\n"
+	out += m.theme.TextAccent().Render(state) + "\n\n"
+
+	switch {
+	case m.account.privacyModeSaving:
+		out += m.theme.TextAccent().Render("saving...") + "\n"
+	case m.account.privacyModeErr != "":
+		out += m.theme.TextError().Render(m.account.privacyModeErr) + "\n"
+	}
+	return out + hintStyle.Render("enter: toggle")
+}
+
+// togglePrivacyMode flips the account privacy default and fires the save command.
+func (m Model) togglePrivacyMode() (Model, tea.Cmd) {
+	if m.account.privacyModeSaving {
+		return m, nil
+	}
+	current := m.User != nil && m.User.PrivacyMode
+	m.account.privacyModeErr = ""
+	m.account.privacyModeSaving = true
+	return m, m.setPrivacyModeCmd(!current)
+}
+
+// setPrivacyModeCmd calls the API off the UI thread and reports back via
+// privacyModeSavedMsg. Mirrors setSpendLimitCmd.
+func (m Model) setPrivacyModeCmd(on bool) tea.Cmd {
+	return func() tea.Msg {
+		if m.APIClient == nil || m.User == nil {
+			return privacyModeSavedMsg{Err: fmt.Errorf("not authenticated")}
+		}
+		err := m.APIClient.SetPrivacyMode(on)
+		return privacyModeSavedMsg{Enabled: on, Err: err}
+	}
+}
+
+// parseSpendLimitInput maps the raw dollar input to a *int of cents. Blank
+// clears the limit (nil -> revert to admin/global). "0" is a real "block
+// everything" ceiling, NOT a clear. Negative, non-numeric, or more-than-2-
+// decimal input is rejected. Parsed as integer cents (dollars*100 + cents) with
+// no float multiply, so an amount like 50.01 never loses a cent to binary
+// rounding. The server still stores cents (api/handlers/account.go).
+func parseSpendLimitInput(s string) (*int, error) {
+	s = strings.TrimSpace(s)
+	s = strings.TrimSpace(strings.TrimPrefix(s, "$"))
+	if s == "" {
+		return nil, nil
+	}
+	if strings.HasPrefix(s, "-") {
+		return nil, fmt.Errorf("limit cannot be negative")
+	}
+
+	whole, frac, hasDot := strings.Cut(s, ".")
+	if whole == "" {
+		whole = "0" // allow ".50"
+	}
+	dollars, err := strconv.Atoi(whole)
+	if err != nil {
+		return nil, fmt.Errorf("enter a dollar amount, e.g 25 or 25.50, or blank to clear")
+	}
+
+	cents := 0
+	if hasDot {
+		switch len(frac) {
+		case 0:
+			// trailing dot, e.g "25." -> treat as .00
+		case 1:
+			frac += "0" // "5" -> 50 cents
+			fallthrough
+		case 2:
+			cents, err = strconv.Atoi(frac)
+			if err != nil {
+				return nil, fmt.Errorf("enter a dollar amount, e.g 25 or 25.00, or blank to clear")
+			}
+		default:
+			return nil, fmt.Errorf("use at most two decimal places, e.g 25.00")
+		}
+	}
+
+	total := dollars*100 + cents
+	return &total, nil
+}
+
+// formatCentsDollars renders an integer cents value as a plain dollar string
+// (no leading "$"), e.g. 2500 -> "25.00", 50 -> "0.50". Used for the input
+// prefill and the current-limit display.
+func formatCentsDollars(cents int) string {
+	return fmt.Sprintf("%d.%02d", cents/100, cents%100)
+}
+
+// defaultAccountFooter is the account-menu footer shown when no sub-view owns
+// the keyboard. Extracted so the spend-limit save/cancel paths can restore it
+// without duplicating the slice.
+func defaultAccountFooter() []footerCommand {
+	return []footerCommand{
+		{key: "j/k", value: "navigate"},
+		{key: "enter", value: "select"},
+		{key: "s", value: "shop"},
+		{key: "c", value: "cart"},
+		{key: "?", value: "help"},
+		{key: "q", value: "quit"},
+	}
+}
+
+// friendlySpendLimitError turns a raw API error into one line of TUI copy.
+// SELF_LIMIT_ABOVE_CAP is the one case worth calling out specifically.
+func friendlySpendLimitError(err error) string {
+	if err == nil {
+		return ""
+	}
+	if strings.Contains(err.Error(), "SELF_LIMIT_ABOVE_CAP") {
+		return "limit can't exceed your account cap"
+	}
+	return "failed to save limit"
+}

pkg/tui/account_test.go

@@ -0,0 +1,119 @@
+package tui
+
+import (
+	"testing"
+
+	tea "charm.land/bubbletea/v2"
+
+	"terminalShop/pkg/models"
+)
+
+func TestParseSpendLimitInput(t *testing.T) {
+	cases := []struct {
+		in      string
+		want    int
+		wantNil bool
+		wantErr bool
+	}{
+		{"", 0, true, false},             // blank clears
+		{"0", 0, false, false},           // $0 is block-all, NOT a clear
+		{"25", 2500, false, false},       // whole dollars
+		{"25.50", 2550, false, false},    // dollars + cents
+		{"25.5", 2550, false, false},     // one decimal => tenths
+		{"0.05", 5, false, false},        // sub-dollar
+		{" $25.00 ", 2500, false, false}, // strips $ and whitespace
+		{".50", 50, false, false},        // leading dot
+		{"-5", 0, false, true},           // negative rejected
+		{"abc", 0, false, true},          // non-numeric rejected
+		{"25.999", 0, false, true},       // too many decimals rejected
+	}
+	for _, tc := range cases {
+		got, err := parseSpendLimitInput(tc.in)
+		if tc.wantErr {
+			if err == nil {
+				t.Errorf("%q: want error, got value %v", tc.in, got)
+			}
+			continue
+		}
+		if err != nil {
+			t.Errorf("%q: unexpected error: %v", tc.in, err)
+			continue
+		}
+		if tc.wantNil {
+			if got != nil {
+				t.Errorf("%q: want nil, got %d", tc.in, *got)
+			}
+			continue
+		}
+		if got == nil || *got != tc.want {
+			t.Errorf("%q: want %d, got %v", tc.in, tc.want, got)
+		}
+	}
+}
+
+func TestSetSpendLimitCmd_NilClient(t *testing.T) {
+	m := NewModel("test")
+	m.APIClient = nil
+	cmd := m.setSpendLimitCmd(nil)
+	if cmd == nil {
+		t.Fatal("setSpendLimitCmd returned nil cmd")
+	}
+	saved, ok := cmd().(spendLimitSavedMsg)
+	if !ok {
+		t.Fatalf("expected spendLimitSavedMsg, got %T", cmd())
+	}
+	if saved.Err == nil {
+		t.Error("expected error when API client is nil")
+	}
+}
+
+// TestSpendLimitFocusFlow: enter focuses the input and prefills from the user's
+// current limit; esc cancels without mutating the stored limit.
+func TestSpendLimitFocusFlow(t *testing.T) {
+	m := NewModel("test")
+	m = m.updateLayout(100, 40)
+	m, _ = m.AccountSwitch()
+	m.User = &models.User{ID: 1, SelfLimitCents: intp(2500)}
+	for i, item := range models.AccountMenuItems {
+		if item == "spend limit" {
+			m.account.cursor = i
+		}
+	}
+
+	m, _ = m.AccountUpdate(tea.KeyPressMsg{Code: tea.KeyEnter})
+	if !m.account.spendLimitFocused {
+		t.Fatal("enter did not focus the spend-limit input")
+	}
+	if got := m.account.spendLimitInput.Value(); got != "25.00" {
+		t.Errorf("prefill: want \"25.00\", got %q", got)
+	}
+
+	m, _ = m.AccountUpdate(tea.KeyPressMsg{Code: tea.KeyEsc})
+	if m.account.spendLimitFocused {
+		t.Error("esc did not blur the spend-limit input")
+	}
+	if m.User.SelfLimitCents == nil || *m.User.SelfLimitCents != 2500 {
+		t.Error("esc must not change the stored limit")
+	}
+}
+
+// TestSpendLimitSavedMsg: the async-result handler updates the local user and
+// clears focus on success.
+func TestSpendLimitSavedMsg(t *testing.T) {
+	m := NewModel("test")
+	m = m.updateLayout(100, 40)
+	m, _ = m.AccountSwitch()
+	m.User = &models.User{ID: 1}
+	m.account.spendLimitFocused = true
+	m.account.spendLimitSaving = true
+
+	m, _ = m.AccountUpdate(spendLimitSavedMsg{Cents: intp(750)})
+	if m.account.spendLimitFocused {
+		t.Error("successful save should blur the input")
+	}
+	if m.User.SelfLimitCents == nil || *m.User.SelfLimitCents != 750 {
+		t.Errorf("save should update local user limit to 750, got %v", m.User.SelfLimitCents)
+	}
+}
+
+func intp(i int) *int { return &i }

pkg/tui/model.go

@@ -8,6 +8,7 @@ import (
 	"time"
 
 	"charm.land/bubbles/v2/key"
+	"charm.land/bubbles/v2/textinput"
 	"charm.land/bubbles/v2/viewport"
 	tea "charm.land/bubbletea/v2"
 	"github.com/stripe/stripe-go/v78"
@@ -191,6 +192,12 @@ type accountState struct {
 	cardCursor         int
 	addressDeleting    *int
 	cardDeleting       *int
+	spendLimitFocused  bool
+	spendLimitInput    textinput.Model
+	spendLimitSaving   bool
+	spendLimitErr      string
+	privacyModeSaving  bool
+	privacyModeErr     string
 	detailViewport     viewport.Model
 	viewportReady      bool
 }
@@ -676,6 +683,51 @@ func (m Model) checkoutWithSavedCard() tea.Cmd {
 	}
 }
 
+// checkoutEphemeralCmd tokenizes the entered card and charges it as a one-time,
+// never-saved card (privacy checkout). Mirrors checkoutWithSavedCard but routes
+// to ConvertCartEphemeral instead of saving the card + SetCartCard. The token is
+// produced the same way as saveCardOnlyCmd (stripetoken.New) and handed straight
+// to the charge — no Card row, no SelectedCard, and the backend detaches the
+// PaymentMethod once the charge settles.
+func (m Model) checkoutEphemeralCmd(form PaymentFormCompleteMsg) tea.Cmd {
+	return func() tea.Msg {
+		if m.APIClient == nil {
+			return CheckoutResultMsg{Err: fmt.Errorf("API client not available")}
+		}
+		if err := m.resolveCartAddress(); err != nil {
+			return CheckoutResultMsg{Err: err}
+		}
+		tok, err := stripetoken.New(&stripe.TokenParams{
+			Card: &stripe.CardParams{
+				Name:       stripe.String(form.CardName),
+				Number:     stripe.String(form.CardNumber),
+				ExpMonth:   stripe.String(form.ExpiryMonth),
+				ExpYear:    stripe.String(form.ExpiryYear),
+				CVC:        stripe.String(form.CVC),
+				AddressZip: stripe.String(form.BillingZip),
+			},
+		})
+		if err != nil {
+			if stripeErr, ok := err.(*stripe.Error); ok {
+				return CheckoutResultMsg{Err: fmt.Errorf("%s", stripeErr.Msg)}
+			}
+			return CheckoutResultMsg{Err: fmt.Errorf("failed to tokenize card: %w", err)}
+		}
+		outcome, err := m.APIClient.ConvertCartEphemeral(tok.ID)
+		if err != nil {
+			return CheckoutResultMsg{Err: err}
+		}
+		if outcome.RequiresAction {
+			return CheckoutResultMsg{
+				OrderID:        outcome.OrderID,
+				RequiresAction: true,
+				RedirectURL:    outcome.RedirectURL,
+			}
+		}
+		return CheckoutResultMsg{OrderID: outcome.Order.ID, Total: outcome.Order.Total}
+	}
+}
+
 // schedulePollOrderStatus sleeps 2s then polls /orders/{id}/status. Used while
 // waiting for the customer to complete 3DS authentication.
 func (m Model) schedulePollOrderStatus(orderID uint) tea.Cmd {

pkg/tui/payment_form.go

@@ -26,6 +26,7 @@ type PaymentFormState struct {
 	ExpiryYear  string
 	CVC         string
 	BillingZip  string
+	SaveCard    bool
 	submitting  bool
 }
 
@@ -38,6 +39,7 @@ type PaymentFormCompleteMsg struct {
 	ExpiryYear  string
 	CVC         string
 	BillingZip  string
+	SaveCard    bool
 }
 
 // CardSavedForReviewMsg is sent after a new card is tokenized and saved
@@ -77,6 +79,13 @@ type PollPaymentTimeoutMsg struct{}
 // buildPaymentForm creates the huh form bound to state's fields.
 // No field-level validators so Tab/Enter move freely.
 func (m Model) buildPaymentForm(state *PaymentFormState) *huh.Form {
+	// The save prompt doubles as the privacy "save anyway?" warning: when the
+	// account privacy default is on, the affirmative choice opposes it, so the
+	// title says so. The user can still pick Save (the per-order override).
+	savePrompt := "Save this card for next time?"
+	if m.User != nil && m.User.PrivacyMode {
+		savePrompt = "Privacy mode is on — saving keeps this card. Save anyway?"
+	}
 	f := huh.NewForm(
 		huh.NewGroup(
 			huh.NewInput().
@@ -109,6 +118,12 @@ func (m Model) buildPaymentForm(state *PaymentFormState) *huh.Form {
 				Title("Billing ZIP").
 				Key("billing_zip").
 				Value(&state.BillingZip),
+			huh.NewConfirm().
+				Key("save_card").
+				Title(savePrompt).
+				Affirmative("Save").
+				Negative("Don't save").
+				Value(&state.SaveCard),
 		),
 	).
 		WithShowErrors(false).
@@ -128,6 +143,11 @@ func (m Model) buildPaymentForm(state *PaymentFormState) *huh.Form {
 func (m Model) InitPaymentForm() *PaymentFormState {
 	state := &PaymentFormState{}
 
+	// Default the save choice from the account privacy setting: privacy users
+	// default to NOT saving (a one-time card); everyone else keeps today's
+	// behaviour of saving the entered card.
+	state.SaveCard = m.User == nil || !m.User.PrivacyMode
+
 	// Pre-fill name and email from user if available
 	if m.User != nil {
 		if m.User.Name != "" {
@@ -241,6 +261,7 @@ func (m Model) UpdatePaymentForm(msg tea.Msg, state *PaymentFormState) tea.Cmd {
 				ExpiryYear:  state.ExpiryYear,
 				CVC:         state.CVC,
 				BillingZip:  state.BillingZip,
+				SaveCard:    state.SaveCard,
 			}
 		}
 	}
@@ -419,7 +440,16 @@ func (m Model) PaymentUpdate(msg tea.Msg) (Model, tea.Cmd) {
 	case PaymentFormCompleteMsg:
 		if m.payment.form != nil && !m.payment.form.submitting {
 			m.payment.form.submitting = true
-			return m, m.saveCardOnlyCmd(msg)
+			if msg.SaveCard {
+				return m, m.saveCardOnlyCmd(msg)
+			}
+			// Privacy checkout: charge a one-time card without saving it. Jump to
+			// the review page in checking-out state so ReviewUpdate handles the
+			// resulting CheckoutResultMsg (same terminal handling as the saved-card
+			// path), then forget the card.
+			m, _ = m.ReviewSwitch()
+			m.CheckingOut = true
+			return m, m.checkoutEphemeralCmd(msg)
 		}
 		return m, nil
 

pkg/tui/update.go

@@ -98,9 +98,11 @@ func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 		}
 		if msg.Data.User.ID != 0 {
 			u := models.User{
-				ID:    msg.Data.User.ID,
-				Name:  msg.Data.User.Email,
-				Email: msg.Data.User.Email,
+				ID:             msg.Data.User.ID,
+				Name:           msg.Data.User.Email,
+				Email:          msg.Data.User.Email,
+				SelfLimitCents: msg.Data.User.SelfLimitCents,
+				PrivacyMode:    msg.Data.User.PrivacyMode,
 			}
 			m.User = &u
 			m.Username = u.Name
@@ -176,6 +178,11 @@ func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 		if m.shipping.form != nil || m.payment.form != nil {
 			break
 		}
+		// spend-limit input owns keys while focused - skip global nav so a
+		// keystroke edits the field instead of switching pages (s/c/a/q/etc...)
+		if m.account.spendLimitFocused {
+			break
+		}
 		// Refund overlay owns input when open; dispatched below before page handlers.
 		if m.refund.open {
 			break