diff --git a/server/internal/api/types.go b/server/internal/api/types.go
index acc5a4e..21ba151 100644
--- a/server/internal/api/types.go
+++ b/server/internal/api/types.go
@@ -198,6 +198,21 @@ type VisitRow struct {
 	Similarity float64        `json:"similarity,omitempty"`
 	Quality    float64        `json:"quality,omitempty"`
 	Attributes map[string]any `json:"attributes,omitempty"`
+
+	// What they bought on that visit, if anything. Attached here because
+	// "when was this customer last in" and "did they buy" are one question
+	// staff ask in one breath, and answering it used to mean two calls and a
+	// join in the client.
+	//
+	// Spend and Currency are omitted when a single visit somehow holds more
+	// than one currency: adding rupees to dollars produces something that
+	// looks like money and is not, and Purchases still says a sale happened.
+	// A purchase with no visit_id is not here at all - it belongs to the
+	// customer rather than to a moment - and is listed by
+	// GET /api/sales?customer=V-42.
+	Purchases int     `json:"purchases,omitempty"`
+	Spend     float64 `json:"spend,omitempty"`
+	Currency  string  `json:"currency,omitempty"`
 }
 
 type Profile struct {
diff --git a/server/internal/store/api_admin_monitor_live_test.go b/server/internal/store/api_admin_monitor_live_test.go
index 47ca749..6888c35 100644
--- a/server/internal/store/api_admin_monitor_live_test.go
+++ b/server/internal/store/api_admin_monitor_live_test.go
@@ -3,6 +3,7 @@ package store
 import (
 	"context"
 	"testing"
+	"time"
 )
 
 // A malformed identifier must MISS, never error.
@@ -55,3 +56,113 @@ func TestLiveMalformedIdentifiersMissRatherThanError(t *testing.T) {
 		t.Errorf("Sale(not-a-uuid) matched %q", s.ID)
 	}
 }
+
+// A customer's history carries what they bought on each visit.
+//
+// Live, because the whole risk is in the SQL: a plain join onto purchases
+// would return a visit TWICE when it holds two sales, making a customer look
+// like they came more often than they did. The LATERAL aggregate is what
+// prevents that, and an in-memory fake asserting on it would only be checking
+// the fake.
+func TestLiveTwoSalesOnOneVisitDoNotDuplicateTheVisit(t *testing.T) {
+	st := liveStore(t)
+	ctx := context.Background()
+
+	clientID, siteID, visitorID, visitID := seedVisitWithSales(t, st, 2)
+
+	rows, err := st.VisitorHistory(ctx, clientID, visitorID, 50)
+	if err != nil {
+		t.Fatal(err)
+	}
+	seen := 0
+	for _, r := range rows {
+		if r.ID != visitID {
+			continue
+		}
+		seen++
+		if r.Purchases != 2 {
+			t.Errorf("purchases = %d, want 2", r.Purchases)
+		}
+		if r.Spend != 300 || r.Currency != "INR" {
+			t.Errorf("spend = %v %s, want 300 INR", r.Spend, r.Currency)
+		}
+	}
+	if seen != 1 {
+		t.Fatalf("the visit appears %d times, want exactly 1 - two sales on one "+
+			"visit must not make a customer look like two visits", seen)
+	}
+	_ = siteID
+}
+
+// Mixed currencies on one visit report the count and NO figure. Adding rupees
+// to dollars produces something that looks like money and is not.
+func TestLiveMixedCurrenciesOnOneVisitReportNoTotal(t *testing.T) {
+	st := liveStore(t)
+	ctx := context.Background()
+
+	clientID, _, visitorID, visitID := seedVisitWithSales(t, st, 0)
+	seedSale(t, st, clientID, visitID, visitorID, 100, "INR")
+	seedSale(t, st, clientID, visitID, visitorID, 50, "USD")
+
+	rows, err := st.VisitorHistory(ctx, clientID, visitorID, 50)
+	if err != nil {
+		t.Fatal(err)
+	}
+	for _, r := range rows {
+		if r.ID != visitID {
+			continue
+		}
+		if r.Purchases != 2 {
+			t.Errorf("purchases = %d, want 2 - the sales still happened", r.Purchases)
+		}
+		if r.Spend != 0 || r.Currency != "" {
+			t.Errorf("spend = %v %q, want no figure for mixed currencies",
+				r.Spend, r.Currency)
+		}
+	}
+}
+
+// seedVisitWithSales makes one tenant, one customer, one visit, and `sales`
+// purchases of 150 INR each against that visit.
+func seedVisitWithSales(t *testing.T, st *Store, sales int) (clientID, siteID, visitorID, visitID string) {
+	t.Helper()
+	clientID, siteID = seedTenant(t, st, "hist"+stamp(), 0, false)
+	ctx := context.Background()
+	at := time.Date(2026, 9, 3, 11, 0, 0, 0, time.UTC)
+
+	if err := st.pool.QueryRow(ctx, `
+		INSERT INTO visitors (client_id, number, label, first_seen_at)
+		VALUES ($1::uuid, 1, 'Visitor 1', $2) RETURNING id::text`,
+		clientID, at).Scan(&visitorID); err != nil {
+		t.Fatalf("seed visitor: %v", err)
+	}
+	if err := st.pool.QueryRow(ctx, `
+		INSERT INTO visits (client_id, site_id, visitor_id, source_event_id,
+		                    occurred_at, camera_id, is_new_visitor)
+		VALUES ($1::uuid, $2::uuid, $3::uuid, 'hist-e1', $4, 'door', true)
+		RETURNING id::text`,
+		clientID, siteID, visitorID, at).Scan(&visitID); err != nil {
+		t.Fatalf("seed visit: %v", err)
+	}
+	for i := 0; i < sales; i++ {
+		seedSale(t, st, clientID, visitID, visitorID, 150, "INR")
+	}
+	return clientID, siteID, visitorID, visitID
+}
+
+func seedSale(t *testing.T, st *Store, clientID, visitID, visitorID string,
+	amount float64, currency string) {
+	t.Helper()
+	var siteID string
+	if err := st.pool.QueryRow(context.Background(),
+		`SELECT site_id::text FROM visits WHERE id = $1::uuid`, visitID).Scan(&siteID); err != nil {
+		t.Fatalf("site of visit: %v", err)
+	}
+	if _, err := st.pool.Exec(context.Background(), `
+		INSERT INTO purchases (client_id, site_id, visitor_id, visit_id,
+		                       amount, currency, occurred_at)
+		VALUES ($1::uuid, $2::uuid, $3::uuid, $4::uuid, $5, $6, now())`,
+		clientID, siteID, visitorID, visitID, amount, currency); err != nil {
+		t.Fatalf("seed sale: %v", err)
+	}
+}
diff --git a/server/internal/store/api_people.go b/server/internal/store/api_people.go
index 20f5dba..1e211e7 100644
--- a/server/internal/store/api_people.go
+++ b/server/internal/store/api_people.go
@@ -94,9 +94,19 @@ func (s *Store) VisitorHistory(ctx context.Context, clientID, visitorID string,
 
 	rows, err := s.pool.Query(ctx, `
 		SELECT vi.id::text, vi.occurred_at, si.name, vi.camera_id,
-		       vi.is_new_visitor, vi.similarity, vi.quality, vi.attributes
+		       vi.is_new_visitor, vi.similarity, vi.quality, vi.attributes,
+		       pu.n, pu.total, pu.cur, pu.currencies
 		FROM visits vi
 		JOIN sites si ON si.id = vi.site_id
+		-- LATERAL rather than a join onto purchases directly: two sales on one
+		-- visit would otherwise return that visit twice and the customer would
+		-- appear to have been in more often than they were.
+		LEFT JOIN LATERAL (
+		  SELECT count(*) AS n, sum(p.amount) AS total,
+		         max(p.currency) AS cur, count(DISTINCT p.currency) AS currencies
+		  FROM purchases p
+		  WHERE p.visit_id = vi.id AND p.client_id = vi.client_id
+		) pu ON true
 		WHERE vi.client_id = $1 AND vi.visitor_id = $2::uuid
 		ORDER BY vi.occurred_at DESC
 		LIMIT $3`, clientID, visitorID, limit)
@@ -109,11 +119,20 @@ func (s *Store) VisitorHistory(ctx context.Context, clientID, visitorID string,
 	for rows.Next() {
 		var v api.VisitRow
 		var at time.Time
-		var sim, qual *float64
+		var sim, qual, total *float64
+		var nPurchases, nCurrencies int
+		var cur *string
 		if err := rows.Scan(&v.ID, &at, &v.Site, &v.CameraID, &v.IsNew,
-			&sim, &qual, &v.Attributes); err != nil {
+			&sim, &qual, &v.Attributes,
+			&nPurchases, &total, &cur, &nCurrencies); err != nil {
 			return nil, err
 		}
+		v.Purchases = nPurchases
+		// One currency or none. Mixed is left as a count with no figure
+		// rather than a sum that means nothing.
+		if nCurrencies == 1 && total != nil && cur != nil {
+			v.Spend, v.Currency = *total, *cur
+		}
 		v.OccurredAt = at.UTC().Format(time.RFC3339)
 		if sim != nil {
 			v.Similarity = *sim