feat(sms): implement SMS messaging and metered billing

Implement a complete SMS messaging system including:
- Integration with SMS Manager.cz API for sending messages.
- Metered billing via Stripe using monthly aggregate invoice items.
- Backend services for managing SMS settings, usage logging, and monthly reporting.
- Database migrations for tenant settings, usage logs, and monthly reports.
- Frontend dashboard components for SMS configuration, usage tracking, and history.
- Support for customer phone numbers in the booking flow.

Includes new migrations, backend services, and frontend UI components.

apps/backend/internal/api/server.go

@@ -3,6 +3,7 @@ package api
 import (
 	"context"
 	"errors"
+	"fmt"
 	"io"
 	"log"
 	"net/http"
@@ -19,6 +20,7 @@ import (
 	"bookra/apps/backend/internal/domain"
 	"bookra/apps/backend/internal/httpx"
 	"bookra/apps/backend/internal/notifications"
+	"bookra/apps/backend/internal/sms"
 	"bookra/apps/backend/internal/tenancy"
 
 	"github.com/getsentry/sentry-go"
@@ -36,6 +38,7 @@ type Server struct {
 	adminService        *admin.Service
 	billingService      *billing.Service
 	notificationService *notifications.Service
+	smsService          *sms.Service
 }
 
 func NewServer(cfg config.Config, pools *db.Pools) (*Server, error) {
@@ -53,6 +56,7 @@ func NewServer(cfg config.Config, pools *db.Pools) (*Server, error) {
 	catalogService := catalog.NewService(repository, billingService, notificationService)
 	authService := auth.NewService(repository, cfg.AuthJWTSecret)
 	adminService := admin.NewService(repository, cfg.AdminEmail, cfg.AdminKey)
+	smsService := sms.NewService(cfg, repository)
 	publicRateLimiter := httpx.NewRateLimiter(rate.Every(time.Second), 5)
 
 	server := &Server{
@@ -64,6 +68,7 @@ func NewServer(cfg config.Config, pools *db.Pools) (*Server, error) {
 		adminService:        adminService,
 		billingService:      billingService,
 		notificationService: notificationService,
+		smsService:          smsService,
 	}
 
 	server.router.Use(gin.Logger(), gin.Recovery(), cors.New(cors.Config{
@@ -339,6 +344,7 @@ func NewServer(cfg config.Config, pools *db.Pools) (*Server, error) {
 			LocationID     *string `json:"locationId"`
 			CustomerName   string  `json:"customerName" binding:"required"`
 			CustomerEmail  string  `json:"customerEmail" binding:"required,email"`
+			CustomerPhone  string  `json:"customerPhone"`
 			Notes          string  `json:"notes"`
 			StartsAt       string  `json:"startsAt" binding:"required"`
 			EndsAt         string  `json:"endsAt" binding:"required"`
@@ -801,6 +807,141 @@ func NewServer(cfg config.Config, pools *db.Pools) (*Server, error) {
 		c.JSON(http.StatusOK, response)
 	})
 
+	// ============================================
+	// SMS API
+	// ============================================
+	protected.GET("/sms/settings", func(c *gin.Context) {
+		membership, err := tenantService.GetTenantMembership(c.Request.Context(), auth.PrincipalFromContext(c))
+		if err != nil {
+			c.JSON(http.StatusNotFound, gin.H{"error": err.Error()})
+			return
+		}
+		settings, err := smsService.GetSettings(c.Request.Context(), membership.Tenant.ID)
+		if err != nil {
+			c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+			return
+		}
+		c.JSON(http.StatusOK, settings)
+	})
+	protected.POST("/sms/settings", func(c *gin.Context) {
+		membership, err := tenantService.GetTenantMembership(c.Request.Context(), auth.PrincipalFromContext(c))
+		if err != nil {
+			c.JSON(http.StatusNotFound, gin.H{"error": err.Error()})
+			return
+		}
+		var request domain.UpdateSMSSettingsRequest
+		if err := c.ShouldBindJSON(&request); err != nil {
+			c.JSON(http.StatusBadRequest, gin.H{"error": "invalid_request"})
+			return
+		}
+		settings, err := smsService.UpdateSettings(c.Request.Context(), membership.Tenant.ID, request)
+		if err != nil {
+			status := http.StatusInternalServerError
+			if errors.Is(err, sms.ErrSMSPlanNotAllowed) {
+				status = http.StatusForbidden
+			}
+			c.JSON(status, gin.H{"error": err.Error()})
+			return
+		}
+		c.JSON(http.StatusOK, settings)
+	})
+	protected.POST("/sms/send", func(c *gin.Context) {
+		membership, err := tenantService.GetTenantMembership(c.Request.Context(), auth.PrincipalFromContext(c))
+		if err != nil {
+			c.JSON(http.StatusNotFound, gin.H{"error": err.Error()})
+			return
+		}
+		var request domain.SendSMSRequest
+		if err := c.ShouldBindJSON(&request); err != nil {
+			c.JSON(http.StatusBadRequest, gin.H{"error": "invalid_request"})
+			return
+		}
+		response, err := smsService.SendMessage(c.Request.Context(), membership.Tenant.ID, request)
+		if err != nil {
+			status := http.StatusInternalServerError
+			switch {
+			case errors.Is(err, sms.ErrSMSNotConfigured), errors.Is(err, sms.ErrSMSNotEnabled):
+				status = http.StatusServiceUnavailable
+			case errors.Is(err, sms.ErrSMSPlanNotAllowed):
+				status = http.StatusForbidden
+			case errors.Is(err, sms.ErrSMSLimitReached):
+				status = http.StatusTooManyRequests
+			case errors.Is(err, sms.ErrSMSInvalidPhone):
+				status = http.StatusBadRequest
+			}
+			c.JSON(status, gin.H{"error": err.Error()})
+			return
+		}
+		c.JSON(http.StatusOK, response)
+	})
+	protected.GET("/sms/usage", func(c *gin.Context) {
+		membership, err := tenantService.GetTenantMembership(c.Request.Context(), auth.PrincipalFromContext(c))
+		if err != nil {
+			c.JSON(http.StatusNotFound, gin.H{"error": err.Error()})
+			return
+		}
+		yearMonth := c.Query("month")
+		if yearMonth == "" {
+			now := time.Now().UTC()
+			yearMonth = fmt.Sprintf("%04d-%02d", now.Year(), now.Month())
+		}
+		report, err := smsService.GetUsage(c.Request.Context(), membership.Tenant.ID, yearMonth)
+		if err != nil {
+			c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+			return
+		}
+		c.JSON(http.StatusOK, report)
+	})
+	protected.GET("/sms/history", func(c *gin.Context) {
+		membership, err := tenantService.GetTenantMembership(c.Request.Context(), auth.PrincipalFromContext(c))
+		if err != nil {
+			c.JSON(http.StatusNotFound, gin.H{"error": err.Error()})
+			return
+		}
+		limit := 50
+		if l, err := strconv.Atoi(c.Query("limit")); err == nil && l > 0 && l <= 100 {
+			limit = l
+		}
+		logs, err := smsService.GetUsageHistory(c.Request.Context(), membership.Tenant.ID, limit)
+		if err != nil {
+			c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+			return
+		}
+		c.JSON(http.StatusOK, gin.H{"logs": logs})
+	})
+	protected.GET("/sms/invoices", func(c *gin.Context) {
+		membership, err := tenantService.GetTenantMembership(c.Request.Context(), auth.PrincipalFromContext(c))
+		if err != nil {
+			c.JSON(http.StatusNotFound, gin.H{"error": err.Error()})
+			return
+		}
+		limit := 12
+		if l, err := strconv.Atoi(c.Query("limit")); err == nil && l > 0 && l <= 24 {
+			limit = l
+		}
+		reports, err := smsService.GetMonthlyReports(c.Request.Context(), membership.Tenant.ID, limit)
+		if err != nil {
+			c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+			return
+		}
+		c.JSON(http.StatusOK, gin.H{"reports": reports})
+	})
+
+	// Internal job endpoint for SMS monthly invoicing
+	server.router.POST("/v1/internal/jobs/sms/invoices", func(c *gin.Context) {
+		if !authorizeJobRunner(c, cfg) {
+			c.JSON(http.StatusUnauthorized, gin.H{"error": "unauthorized"})
+			return
+		}
+		yearMonth := c.Query("month")
+		response, err := smsService.GenerateMonthlyInvoices(c.Request.Context(), yearMonth, notificationService)
+		if err != nil {
+			c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+			return
+		}
+		c.JSON(http.StatusOK, response)
+	})
+
 	server.router.POST("/v1/webhooks/paddle", func(c *gin.Context) {
 		if err := billingService.HandleWebhook(c.Request.Context(), c.Request); err != nil {
 			c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})

apps/backend/internal/billing/service.go

@@ -780,6 +780,7 @@ func entitlementsForPlan(planCode string) domain.PlanEntitlements {
 			WidgetEmbedding:   true,
 			UmamiTracking:     false,
 			APIAccess:         false,
+			SMSAvailable:      false,
 		}
 	case "business":
 		// Business: Unlimited everything, API access, dedicated manager
@@ -793,6 +794,7 @@ func entitlementsForPlan(planCode string) domain.PlanEntitlements {
 			UmamiTracking:     true,
 			APIAccess:         true,
 			DedicatedManager:  true,
+			SMSAvailable:      true,
 		}
 	default:
 		// Pro: 3 locations, 10 staff, unlimited bookings, email reminders, analytics
@@ -805,6 +807,7 @@ func entitlementsForPlan(planCode string) domain.PlanEntitlements {
 			WidgetEmbedding:   true,
 			UmamiTracking:     true,
 			APIAccess:         false,
+			SMSAvailable:      true,
 		}
 	}
 }

apps/backend/internal/billing/service_test.go

@@ -52,7 +52,7 @@ func TestCreateCheckoutRequiresPaddleConfig(t *testing.T) {
 	response, err := service.CreateCheckoutSession(context.Background(), domain.Principal{
 		Subject: "demo-owner",
 		Email:   "owner@bookra.dev",
-	}, "pro", "czk")
+	}, "pro", "czk", "monthly")
 	if err != ErrPaddleNotConfigured {
 		t.Fatalf("expected ErrPaddleNotConfigured, got response=%v err=%v", response, err)
 	}
@@ -64,7 +64,7 @@ func TestCreateCheckoutReturnsLaunchPayload(t *testing.T) {
 	response, err := service.CreateCheckoutSession(context.Background(), domain.Principal{
 		Subject: "demo-owner",
 		Email:   "owner@bookra.dev",
-	}, "pro", "czk")
+	}, "pro", "czk", "monthly")
 	if err != nil {
 		t.Fatalf("create checkout: %v", err)
 	}

apps/backend/internal/bookings/service.go

@@ -122,6 +122,7 @@ func (s *Service) Create(ctx context.Context, request domain.CreateBookingReques
 
 	customerName := strings.TrimSpace(request.CustomerName)
 	customerEmail := strings.TrimSpace(request.CustomerEmail)
+	customerPhone := strings.TrimSpace(request.CustomerPhone)
 	notes := strings.TrimSpace(request.Notes)
 	if len(customerName) < 2 || len(customerName) > 120 {
 		return domain.CreateBookingResponse{}, fmt.Errorf("%w: customerName must be between 2 and 120 characters", ErrInvalidBooking)
@@ -129,6 +130,9 @@ func (s *Service) Create(ctx context.Context, request domain.CreateBookingReques
 	if _, err := mail.ParseAddress(customerEmail); err != nil {
 		return domain.CreateBookingResponse{}, fmt.Errorf("%w: customerEmail must be valid", ErrInvalidBooking)
 	}
+	if customerPhone != "" && len(customerPhone) > 30 {
+		return domain.CreateBookingResponse{}, fmt.Errorf("%w: customerPhone must be at most 30 characters", ErrInvalidBooking)
+	}
 	if len(notes) > 1000 {
 		return domain.CreateBookingResponse{}, fmt.Errorf("%w: notes must be at most 1000 characters", ErrInvalidBooking)
 	}
@@ -194,6 +198,7 @@ func (s *Service) Create(ctx context.Context, request domain.CreateBookingReques
 		BookingMode:    request.BookingMode,
 		CustomerName:   customerName,
 		CustomerEmail:  customerEmail,
+		CustomerPhone:  customerPhone,
 		StartsAt:       startsAt.UTC(),
 		EndsAt:         endsAt.UTC(),
 		Status:         status,

apps/backend/internal/config/config.go

@@ -10,64 +10,70 @@ import (
 )
 
 type Config struct {
-	Environment       string
-	Port              string
-	APIURL            string
-	FrontendURL       string
-	DatabaseURL       string
-	DatabaseDirectURL string
-	NeonAuthURL       string
-	AuthJWTSecret     string
-	JobRunnerKey      string
-	EmailFrom         string
-	SMTPHost          string
-	SMTPPort          string
-	SMTPUsername      string
-	SMTPPassword      string
-	PaddleEnvironment string
-	PaddleAPIKey      string
-	PaddleWebhookKey  string
-	PaddlePriceMatrix map[string]map[string]string
-	StripeAPIKey      string
-	StripeWebhookKey  string
-	StripePriceMatrix map[string]map[string]string
-	AdminEmail        string
-	AdminKey          string
-	UmamiAPIURL       string
-	UmamiAPIKey       string
-	SentryDSN         string
-	DemoMode          bool
+	Environment          string
+	Port                 string
+	APIURL               string
+	FrontendURL          string
+	DatabaseURL          string
+	DatabaseDirectURL    string
+	NeonAuthURL          string
+	AuthJWTSecret        string
+	JobRunnerKey         string
+	EmailFrom            string
+	SMTPHost             string
+	SMTPPort             string
+	SMTPUsername         string
+	SMTPPassword         string
+	PaddleEnvironment    string
+	PaddleAPIKey         string
+	PaddleWebhookKey     string
+	PaddlePriceMatrix    map[string]map[string]string
+	StripeAPIKey         string
+	StripeWebhookKey     string
+	StripePriceMatrix    map[string]map[string]string
+	AdminEmail           string
+	AdminKey             string
+	UmamiAPIURL          string
+	UmamiAPIKey          string
+	SentryDSN            string
+	DemoMode             bool
+	SMSManagerAPIKey     string
+	SMSManagerBaseURL    string
+	StripeSMSPriceMatrix map[string]string // currency -> price ID (czk, usd, eur, gbp, ...)
 }
 
 func Load() (Config, error) {
 	cfg := Config{
-		Environment:       valueOrDefault("BOOKRA_APP_ENV", "development"),
-		Port:              valueOrDefault("BOOKRA_API_PORT", "8080"),
-		APIURL:            valueOrDefault("BOOKRA_API_URL", "http://localhost:8080"),
-		FrontendURL:       valueOrDefault("BOOKRA_FRONTEND_URL", "http://localhost:3000"),
-		DatabaseURL:       strings.TrimSpace(os.Getenv("BOOKRA_DATABASE_URL")),
-		DatabaseDirectURL: strings.TrimSpace(os.Getenv("BOOKRA_DATABASE_DIRECT_URL")),
-		NeonAuthURL:       strings.TrimSpace(os.Getenv("BOOKRA_NEON_AUTH_URL")),
-		AuthJWTSecret:     strings.TrimSpace(os.Getenv("BOOKRA_AUTH_JWT_SECRET")),
-		JobRunnerKey:      strings.TrimSpace(os.Getenv("BOOKRA_JOB_RUNNER_KEY")),
-		EmailFrom:         valueOrDefault("BOOKRA_EMAIL_FROM", "noreply@bookra.dev"),
-		SMTPHost:          strings.TrimSpace(os.Getenv("BOOKRA_SMTP_HOST")),
-		SMTPPort:          valueOrDefault("BOOKRA_SMTP_PORT", "587"),
-		SMTPUsername:      strings.TrimSpace(os.Getenv("BOOKRA_SMTP_USERNAME")),
-		SMTPPassword:      strings.TrimSpace(os.Getenv("BOOKRA_SMTP_PASSWORD")),
-		PaddleEnvironment: normalizePaddleEnvironment(os.Getenv("BOOKRA_PADDLE_ENV")),
-		PaddleAPIKey:      strings.TrimSpace(os.Getenv("BOOKRA_PADDLE_API_KEY")),
-		PaddleWebhookKey:  strings.TrimSpace(os.Getenv("BOOKRA_PADDLE_WEBHOOK_SECRET")),
-		PaddlePriceMatrix: paddlePriceMatrixFromEnv(),
-		StripeAPIKey:      strings.TrimSpace(os.Getenv("BOOKRA_STRIPE_API_KEY")),
-		StripeWebhookKey:  strings.TrimSpace(os.Getenv("BOOKRA_STRIPE_WEBHOOK_SECRET")),
-		StripePriceMatrix: stripePriceMatrixFromEnv(),
-		AdminEmail:        strings.TrimSpace(os.Getenv("BOOKRA_ADMIN_EMAIL")),
-		AdminKey:          strings.TrimSpace(os.Getenv("BOOKRA_ADMIN_KEY")),
-		UmamiAPIURL:       strings.TrimSpace(os.Getenv("BOOKRA_UMAMI_API_URL")),
-		UmamiAPIKey:       strings.TrimSpace(os.Getenv("BOOKRA_UMAMI_API_KEY")),
-		SentryDSN:         strings.TrimSpace(os.Getenv("BOOKRA_SENTRY_DSN")),
-		DemoMode:          boolFromEnv("BOOKRA_DEMO_MODE", false),
+		Environment:          valueOrDefault("BOOKRA_APP_ENV", "development"),
+		Port:                 valueOrDefault("BOOKRA_API_PORT", "8080"),
+		APIURL:               valueOrDefault("BOOKRA_API_URL", "http://localhost:8080"),
+		FrontendURL:          valueOrDefault("BOOKRA_FRONTEND_URL", "http://localhost:3000"),
+		DatabaseURL:          strings.TrimSpace(os.Getenv("BOOKRA_DATABASE_URL")),
+		DatabaseDirectURL:    strings.TrimSpace(os.Getenv("BOOKRA_DATABASE_DIRECT_URL")),
+		NeonAuthURL:          strings.TrimSpace(os.Getenv("BOOKRA_NEON_AUTH_URL")),
+		AuthJWTSecret:        strings.TrimSpace(os.Getenv("BOOKRA_AUTH_JWT_SECRET")),
+		JobRunnerKey:         strings.TrimSpace(os.Getenv("BOOKRA_JOB_RUNNER_KEY")),
+		EmailFrom:            valueOrDefault("BOOKRA_EMAIL_FROM", "noreply@bookra.dev"),
+		SMTPHost:             strings.TrimSpace(os.Getenv("BOOKRA_SMTP_HOST")),
+		SMTPPort:             valueOrDefault("BOOKRA_SMTP_PORT", "587"),
+		SMTPUsername:         strings.TrimSpace(os.Getenv("BOOKRA_SMTP_USERNAME")),
+		SMTPPassword:         strings.TrimSpace(os.Getenv("BOOKRA_SMTP_PASSWORD")),
+		PaddleEnvironment:    normalizePaddleEnvironment(os.Getenv("BOOKRA_PADDLE_ENV")),
+		PaddleAPIKey:         strings.TrimSpace(os.Getenv("BOOKRA_PADDLE_API_KEY")),
+		PaddleWebhookKey:     strings.TrimSpace(os.Getenv("BOOKRA_PADDLE_WEBHOOK_SECRET")),
+		PaddlePriceMatrix:    paddlePriceMatrixFromEnv(),
+		StripeAPIKey:         strings.TrimSpace(os.Getenv("BOOKRA_STRIPE_API_KEY")),
+		StripeWebhookKey:     strings.TrimSpace(os.Getenv("BOOKRA_STRIPE_WEBHOOK_SECRET")),
+		StripePriceMatrix:    stripePriceMatrixFromEnv(),
+		AdminEmail:           strings.TrimSpace(os.Getenv("BOOKRA_ADMIN_EMAIL")),
+		AdminKey:             strings.TrimSpace(os.Getenv("BOOKRA_ADMIN_KEY")),
+		UmamiAPIURL:          strings.TrimSpace(os.Getenv("BOOKRA_UMAMI_API_URL")),
+		UmamiAPIKey:          strings.TrimSpace(os.Getenv("BOOKRA_UMAMI_API_KEY")),
+		SentryDSN:            strings.TrimSpace(os.Getenv("BOOKRA_SENTRY_DSN")),
+		DemoMode:             boolFromEnv("BOOKRA_DEMO_MODE", false),
+		SMSManagerAPIKey:     strings.TrimSpace(os.Getenv("BOOKRA_SMSMANAGER_API_KEY")),
+		SMSManagerBaseURL:    valueOrDefault("BOOKRA_SMSMANAGER_BASE_URL", "https://api.smsmngr.com/v2"),
+		StripeSMSPriceMatrix: smsPriceMatrixFromEnv(),
 	}
 
 	if cfg.FrontendURL == "" {
@@ -158,6 +164,25 @@ func (cfg Config) BillingWebhookConfigured() bool {
 	return cfg.StripeWebhookConfigured() || cfg.PaddleWebhookConfigured()
 }
 
+func (cfg Config) SMSConfigured() bool {
+	return strings.TrimSpace(cfg.SMSManagerAPIKey) != ""
+}
+
+func (cfg Config) StripeSMSConfigured() bool {
+	return cfg.StripeConfigured() && cfg.StripeSMSPriceMatrix["czk"] != ""
+}
+
+func (cfg Config) StripeSMSPriceID(currency string) string {
+	c := strings.ToLower(strings.TrimSpace(currency))
+	if c == "" {
+		c = "czk"
+	}
+	if id := cfg.StripeSMSPriceMatrix[c]; id != "" {
+		return id
+	}
+	return cfg.StripeSMSPriceMatrix["czk"]
+}
+
 func paddlePriceMatrixFromEnv() map[string]map[string]string {
 	matrix := map[string]map[string]string{
 		"starter":  {},
@@ -223,6 +248,15 @@ func boolFromEnv(key string, fallback bool) bool {
 	return value == "true" || value == "1" || value == "yes" || value == "on"
 }
 
+func smsPriceMatrixFromEnv() map[string]string {
+	matrix := map[string]string{}
+	for _, currency := range []string{"czk", "usd", "eur", "gbp", "pln"} {
+		upper := strings.ToUpper(currency)
+		matrix[currency] = strings.TrimSpace(os.Getenv("BOOKRA_STRIPE_SMS_" + upper + "_PRICE_ID"))
+	}
+	return matrix
+}
+
 func uniqueStrings(values []string) []string {
 	seen := map[string]struct{}{}
 	out := make([]string, 0, len(values))

apps/backend/internal/db/bookings.go

@@ -1,14 +1,14 @@
 package db
 
 import (
-"context"
-"time"
+	"context"
+	"time"
 )
 
 func (r *PGRepository) ListBookingsByTenantBetween(ctx context.Context, tenantID string, from time.Time, to time.Time) ([]BookingRecord, error) {
 	rows, err := r.pool.Query(ctx, `
 		SELECT id, tenant_id, service_id, class_session_id, staff_id, location_id,
-		       customer_name, customer_email, starts_at, ends_at, status, reference
+		       customer_name, customer_email, customer_phone, starts_at, ends_at, status, reference
 		FROM bookings
 		WHERE tenant_id = $1 AND starts_at < $3 AND ends_at > $2
 		ORDER BY starts_at ASC
@@ -30,6 +30,7 @@ func (r *PGRepository) ListBookingsByTenantBetween(ctx context.Context, tenantID
 			&record.LocationID,
 			&record.CustomerName,
 			&record.CustomerEmail,
+			&record.CustomerPhone,
 			&record.StartsAt,
 			&record.EndsAt,
 			&record.Status,
@@ -47,10 +48,10 @@ func (r *PGRepository) CreateBooking(ctx context.Context, params CreateBookingPa
 	err := r.pool.QueryRow(ctx, `
 		INSERT INTO bookings (
 			tenant_id, service_id, class_session_id, staff_id, location_id,
-			booking_mode, customer_name, customer_email, starts_at, ends_at,
+			booking_mode, customer_name, customer_email, customer_phone, starts_at, ends_at,
 			status, reference, notes
 		)
-		VALUES ($1,$2,$3,$4,$5,$6,$7,$8,$9,$10,$11,$12,$13)
+		VALUES ($1,$2,$3,$4,$5,$6,$7,$8,$9,$10,$11,$12,$13,$14)
 		RETURNING id, reference, status
 	`,
 		params.TenantID,
@@ -61,6 +62,7 @@ func (r *PGRepository) CreateBooking(ctx context.Context, params CreateBookingPa
 		params.BookingMode,
 		params.CustomerName,
 		params.CustomerEmail,
+		params.CustomerPhone,
 		params.StartsAt,
 		params.EndsAt,
 		params.Status,

apps/backend/internal/db/repository.go

@@ -86,6 +86,18 @@ type Repository interface {
 	// Working Hours
 	ListWorkingHoursByTenant(ctx context.Context, tenantID string) ([]WorkingHoursRecord, error)
 	UpdateWorkingHours(ctx context.Context, tenantID string, dayOfWeek int, params UpdateWorkingHoursParams) error
+
+	// SMS
+	GetTenantSMSSettings(ctx context.Context, tenantID string) (TenantSMSSettingsRecord, error)
+	UpsertTenantSMSSettings(ctx context.Context, params TenantSMSSettingsRecord) error
+	CreateSMSUsageLog(ctx context.Context, params SMSUsageLogRecord) (string, error)
+	GetSMSUsageThisMonth(ctx context.Context, tenantID string) (SMSUsageSummary, error)
+	GetSMSUsageForMonth(ctx context.Context, tenantID string, yearMonth string) (SMSMonthlyReportRecord, error)
+	ListSMSUsageLogs(ctx context.Context, tenantID string, limit int) ([]SMSUsageLogRecord, error)
+	ListSMSMonthlyReports(ctx context.Context, tenantID string, limit int) ([]SMSMonthlyReportRecord, error)
+	UpsertSMSMonthlyReport(ctx context.Context, params SMSMonthlyReportRecord) error
+	MarkSMSReportInvoiceSent(ctx context.Context, tenantID string, yearMonth string) error
+	ListTenantsWithSMSUsage(ctx context.Context, yearMonth string) ([]TenantRecord, error)
 }
 
 type TenantRecord struct {
@@ -124,12 +136,12 @@ type MagicLinkRecord struct {
 }
 
 type PlatformStats struct {
-	TotalTenants       int64 `json:"totalTenants"`
-	TotalUsers         int64 `json:"totalUsers"`
+	TotalTenants        int64 `json:"totalTenants"`
+	TotalUsers          int64 `json:"totalUsers"`
 	ActiveSubscriptions int64 `json:"activeSubscriptions"`
 	TrialSubscriptions  int64 `json:"trialSubscriptions"`
-	BookingsThisMonth  int64 `json:"bookingsThisMonth"`
-	RevenueThisMonth   int64 `json:"revenueThisMonthCents"`
+	BookingsThisMonth   int64 `json:"bookingsThisMonth"`
+	RevenueThisMonth    int64 `json:"revenueThisMonthCents"`
 }
 
 type AdminAuditLogParams struct {
@@ -229,6 +241,7 @@ type BookingRecord struct {
 	LocationID     *string
 	CustomerName   string
 	CustomerEmail  string
+	CustomerPhone  string
 	StartsAt       time.Time
 	EndsAt         time.Time
 	Status         string
@@ -244,6 +257,7 @@ type CreateBookingParams struct {
 	BookingMode    string
 	CustomerName   string
 	CustomerEmail  string
+	CustomerPhone  string
 	StartsAt       time.Time
 	EndsAt         time.Time
 	Status         string
@@ -414,6 +428,44 @@ type UpdateWorkingHoursParams struct {
 	IsOpen      *bool
 }
 
+// SMS Records
+type TenantSMSSettingsRecord struct {
+	TenantID                 string
+	Enabled                  bool
+	SenderName               string
+	MonthlyLimit             int
+	StripeSubscriptionItemID string
+}
+
+type SMSUsageLogRecord struct {
+	ID                string
+	TenantID          string
+	RecipientPhone    string
+	MessageBody       string
+	ExternalMessageID string
+	ExternalRequestID string
+	Status            string
+	CostCents         int
+	SentAt            time.Time
+	CreatedAt         time.Time
+}
+
+type SMSUsageSummary struct {
+	MessageCount   int
+	TotalCostCents int
+}
+
+type SMSMonthlyReportRecord struct {
+	ID              string
+	TenantID        string
+	YearMonth       string
+	MessageCount    int
+	TotalCostCents  int
+	StripeInvoiceID string
+	InvoiceSentAt   *time.Time
+	CreatedAt       time.Time
+}
+
 type PGRepository struct {
 	pool *pgxpool.Pool
 }
@@ -428,46 +480,14 @@ func NewRepository(pools *Pools, demoMode bool) Repository {
 	return NewMemoryRepository()
 }
 
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
 // ============================================
 // LOCATION / ZONE METHODS - PG REPOSITORY (STUBS)
 // ============================================
 
-
-
-
-
-
 // ============================================
 // BLOCKED DAYS METHODS - PG REPOSITORY (STUBS)
 // ============================================
 
-
-
-
-
 // ============================================
 // CUSTOMER METHODS - PG REPOSITORY (STUBS)
 // ============================================
@@ -572,11 +592,11 @@ func (r *PGRepository) GetBookingByReference(ctx context.Context, reference stri
 	var rec BookingRecord
 	err := r.pool.QueryRow(ctx, `
 		SELECT id, tenant_id, service_id, class_session_id, staff_id, location_id,
-		       customer_name, customer_email, starts_at, ends_at, status, reference
+		       customer_name, customer_email, customer_phone, starts_at, ends_at, status, reference
 		FROM bookings
 		WHERE reference = $1
 	`, reference).Scan(&rec.ID, &rec.TenantID, &rec.ServiceID, &rec.ClassSessionID, &rec.StaffID, &rec.LocationID,
-		&rec.CustomerName, &rec.CustomerEmail, &rec.StartsAt, &rec.EndsAt, &rec.Status, &rec.Reference)
+		&rec.CustomerName, &rec.CustomerEmail, &rec.CustomerPhone, &rec.StartsAt, &rec.EndsAt, &rec.Status, &rec.Reference)
 	return rec, err
 }
 
@@ -598,8 +618,6 @@ func (r *PGRepository) RescheduleBooking(ctx context.Context, bookingID string,
 // WORKING HOURS METHODS - PG REPOSITORY (STUBS)
 // ============================================
 
-
-
 type MemoryRepository struct {
 	tenant          TenantRecord
 	membership      TenantMembershipRecord
@@ -617,6 +635,9 @@ type MemoryRepository struct {
 	blockedDays     []BlockedDayRecord
 	customers       []CustomerRecord
 	workingHours    []WorkingHoursRecord
+	smsSettings     TenantSMSSettingsRecord
+	smsLogs         []SMSUsageLogRecord
+	smsReports      []SMSMonthlyReportRecord
 }
 
 func NewMemoryRepository() *MemoryRepository {

apps/backend/internal/db/sms.go

@@ -0,0 +1,280 @@
+package db
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"github.com/jackc/pgx/v5"
+)
+
+// ============================================
+// SMS SETTINGS - PG REPOSITORY
+// ============================================
+
+func (r *PGRepository) GetTenantSMSSettings(ctx context.Context, tenantID string) (TenantSMSSettingsRecord, error) {
+	var rec TenantSMSSettingsRecord
+	err := r.pool.QueryRow(ctx, `
+		SELECT tenant_id, enabled, COALESCE(sender_name, ''), COALESCE(monthly_limit, 0), COALESCE(stripe_subscription_item_id, '')
+		FROM tenant_sms_settings
+		WHERE tenant_id = $1
+	`, tenantID).Scan(&rec.TenantID, &rec.Enabled, &rec.SenderName, &rec.MonthlyLimit, &rec.StripeSubscriptionItemID)
+	if err != nil {
+		if err == pgx.ErrNoRows {
+			return TenantSMSSettingsRecord{TenantID: tenantID}, nil
+		}
+		return TenantSMSSettingsRecord{}, err
+	}
+	return rec, nil
+}
+
+func (r *PGRepository) UpsertTenantSMSSettings(ctx context.Context, params TenantSMSSettingsRecord) error {
+	_, err := r.pool.Exec(ctx, `
+		INSERT INTO tenant_sms_settings (tenant_id, enabled, sender_name, monthly_limit, stripe_subscription_item_id, updated_at)
+		VALUES ($1, $2, $3, $4, $5, now())
+		ON CONFLICT (tenant_id) DO UPDATE SET
+			enabled = EXCLUDED.enabled,
+			sender_name = EXCLUDED.sender_name,
+			monthly_limit = EXCLUDED.monthly_limit,
+			stripe_subscription_item_id = EXCLUDED.stripe_subscription_item_id,
+			updated_at = now()
+	`, params.TenantID, params.Enabled, params.SenderName, params.MonthlyLimit, params.StripeSubscriptionItemID)
+	return err
+}
+
+// ============================================
+// SMS USAGE LOGS - PG REPOSITORY
+// ============================================
+
+func (r *PGRepository) CreateSMSUsageLog(ctx context.Context, params SMSUsageLogRecord) (string, error) {
+	var id string
+	err := r.pool.QueryRow(ctx, `
+		INSERT INTO sms_usage_logs (tenant_id, recipient_phone, message_body, external_message_id, external_request_id, status, cost_cents, sent_at)
+		VALUES ($1, $2, $3, $4, $5, $6, $7, $8)
+		RETURNING id
+	`, params.TenantID, params.RecipientPhone, params.MessageBody, params.ExternalMessageID, params.ExternalRequestID, params.Status, params.CostCents, params.SentAt).Scan(&id)
+	return id, err
+}
+
+func (r *PGRepository) GetSMSUsageThisMonth(ctx context.Context, tenantID string) (SMSUsageSummary, error) {
+	var summary SMSUsageSummary
+	err := r.pool.QueryRow(ctx, `
+		SELECT COALESCE(COUNT(*), 0), COALESCE(SUM(cost_cents), 0)
+		FROM sms_usage_logs
+		WHERE tenant_id = $1 AND date_trunc('month', created_at) = date_trunc('month', now())
+	`, tenantID).Scan(&summary.MessageCount, &summary.TotalCostCents)
+	return summary, err
+}
+
+func (r *PGRepository) GetSMSUsageForMonth(ctx context.Context, tenantID string, yearMonth string) (SMSMonthlyReportRecord, error) {
+	var rec SMSMonthlyReportRecord
+	err := r.pool.QueryRow(ctx, `
+		SELECT COALESCE(COUNT(*), 0), COALESCE(SUM(cost_cents), 0)
+		FROM sms_usage_logs
+		WHERE tenant_id = $1 AND to_char(created_at, 'YYYY-MM') = $2
+	`, tenantID, yearMonth).Scan(&rec.MessageCount, &rec.TotalCostCents)
+	if err != nil {
+		return SMSMonthlyReportRecord{}, err
+	}
+	rec.TenantID = tenantID
+	rec.YearMonth = yearMonth
+	return rec, nil
+}
+
+func (r *PGRepository) ListSMSUsageLogs(ctx context.Context, tenantID string, limit int) ([]SMSUsageLogRecord, error) {
+	rows, err := r.pool.Query(ctx, `
+		SELECT id, tenant_id, recipient_phone, message_body, external_message_id, external_request_id, status, cost_cents, created_at
+		FROM sms_usage_logs
+		WHERE tenant_id = $1
+		ORDER BY created_at DESC
+		LIMIT $2
+	`, tenantID, limit)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	var records []SMSUsageLogRecord
+	for rows.Next() {
+		var rec SMSUsageLogRecord
+		if err := rows.Scan(&rec.ID, &rec.TenantID, &rec.RecipientPhone, &rec.MessageBody, &rec.ExternalMessageID, &rec.ExternalRequestID, &rec.Status, &rec.CostCents, &rec.CreatedAt); err != nil {
+			return nil, err
+		}
+		records = append(records, rec)
+	}
+	return records, rows.Err()
+}
+
+func (r *PGRepository) ListSMSMonthlyReports(ctx context.Context, tenantID string, limit int) ([]SMSMonthlyReportRecord, error) {
+	rows, err := r.pool.Query(ctx, `
+		SELECT id, tenant_id, year_month, message_count, total_cost_cents, stripe_invoice_id, invoice_sent_at, created_at
+		FROM sms_monthly_reports
+		WHERE tenant_id = $1
+		ORDER BY year_month DESC
+		LIMIT $2
+	`, tenantID, limit)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	var records []SMSMonthlyReportRecord
+	for rows.Next() {
+		var rec SMSMonthlyReportRecord
+		if err := rows.Scan(&rec.ID, &rec.TenantID, &rec.YearMonth, &rec.MessageCount, &rec.TotalCostCents, &rec.StripeInvoiceID, &rec.InvoiceSentAt, &rec.CreatedAt); err != nil {
+			return nil, err
+		}
+		records = append(records, rec)
+	}
+	return records, rows.Err()
+}
+
+func (r *PGRepository) UpsertSMSMonthlyReport(ctx context.Context, params SMSMonthlyReportRecord) error {
+	_, err := r.pool.Exec(ctx, `
+		INSERT INTO sms_monthly_reports (tenant_id, year_month, message_count, total_cost_cents, stripe_invoice_id)
+		VALUES ($1, $2, $3, $4, $5)
+		ON CONFLICT (tenant_id, year_month) DO UPDATE SET
+			message_count = EXCLUDED.message_count,
+			total_cost_cents = EXCLUDED.total_cost_cents,
+			stripe_invoice_id = EXCLUDED.stripe_invoice_id,
+			created_at = now()
+	`, params.TenantID, params.YearMonth, params.MessageCount, params.TotalCostCents, params.StripeInvoiceID)
+	return err
+}
+
+func (r *PGRepository) MarkSMSReportInvoiceSent(ctx context.Context, tenantID string, yearMonth string) error {
+	_, err := r.pool.Exec(ctx, `
+		UPDATE sms_monthly_reports
+		SET invoice_sent_at = now()
+		WHERE tenant_id = $1 AND year_month = $2
+	`, tenantID, yearMonth)
+	return err
+}
+
+func (r *PGRepository) ListTenantsWithSMSUsage(ctx context.Context, yearMonth string) ([]TenantRecord, error) {
+	rows, err := r.pool.Query(ctx, `
+		SELECT DISTINCT t.id, t.slug, t.name, t.preset, t.locale, t.timezone, t.plan_code, t.subscription_status,
+		       t.billing_provider, t.billing_customer_id, t.billing_subscription_id
+		FROM tenants t
+		JOIN tenant_sms_settings s ON s.tenant_id = t.id AND s.enabled = true
+		JOIN sms_usage_logs l ON l.tenant_id = t.id AND to_char(l.created_at, 'YYYY-MM') = $1
+	`, yearMonth)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	var records []TenantRecord
+	for rows.Next() {
+		var rec TenantRecord
+		if err := rows.Scan(&rec.ID, &rec.Slug, &rec.Name, &rec.Preset, &rec.Locale, &rec.Timezone, &rec.PlanCode, &rec.SubscriptionStatus,
+			&rec.BillingProvider, &rec.BillingCustomerID, &rec.BillingSubscription); err != nil {
+			return nil, err
+		}
+		records = append(records, rec)
+	}
+	return records, rows.Err()
+}
+
+// ============================================
+// SMS SETTINGS - MEMORY REPOSITORY
+// ============================================
+
+func (r *MemoryRepository) GetTenantSMSSettings(_ context.Context, tenantID string) (TenantSMSSettingsRecord, error) {
+	if tenantID != r.tenant.ID {
+		return TenantSMSSettingsRecord{}, pgx.ErrNoRows
+	}
+	return r.smsSettings, nil
+}
+
+func (r *MemoryRepository) UpsertTenantSMSSettings(_ context.Context, params TenantSMSSettingsRecord) error {
+	r.smsSettings = params
+	return nil
+}
+
+func (r *MemoryRepository) CreateSMSUsageLog(_ context.Context, params SMSUsageLogRecord) (string, error) {
+	params.ID = fmt.Sprintf("sms-%d", len(r.smsLogs))
+	params.CreatedAt = time.Now().UTC()
+	r.smsLogs = append([]SMSUsageLogRecord{params}, r.smsLogs...)
+	return params.ID, nil
+}
+
+func (r *MemoryRepository) GetSMSUsageThisMonth(_ context.Context, tenantID string) (SMSUsageSummary, error) {
+	if tenantID != r.tenant.ID {
+		return SMSUsageSummary{}, nil
+	}
+	now := time.Now().UTC()
+	var count, cost int
+	for _, log := range r.smsLogs {
+		if log.TenantID == tenantID && log.CreatedAt.Year() == now.Year() && log.CreatedAt.Month() == now.Month() {
+			count++
+			cost += log.CostCents
+		}
+	}
+	return SMSUsageSummary{MessageCount: count, TotalCostCents: cost}, nil
+}
+
+func (r *MemoryRepository) GetSMSUsageForMonth(_ context.Context, tenantID string, yearMonth string) (SMSMonthlyReportRecord, error) {
+	if tenantID != r.tenant.ID {
+		return SMSMonthlyReportRecord{}, nil
+	}
+	var count, cost int
+	for _, log := range r.smsLogs {
+		if log.TenantID == tenantID && log.CreatedAt.Format("2006-01") == yearMonth {
+			count++
+			cost += log.CostCents
+		}
+	}
+	return SMSMonthlyReportRecord{TenantID: tenantID, YearMonth: yearMonth, MessageCount: count, TotalCostCents: cost}, nil
+}
+
+func (r *MemoryRepository) ListSMSUsageLogs(_ context.Context, tenantID string, limit int) ([]SMSUsageLogRecord, error) {
+	if tenantID != r.tenant.ID {
+		return nil, nil
+	}
+	if limit > len(r.smsLogs) {
+		limit = len(r.smsLogs)
+	}
+	return r.smsLogs[:limit], nil
+}
+
+func (r *MemoryRepository) ListSMSMonthlyReports(_ context.Context, tenantID string, limit int) ([]SMSMonthlyReportRecord, error) {
+	if tenantID != r.tenant.ID {
+		return nil, nil
+	}
+	if limit > len(r.smsReports) {
+		limit = len(r.smsReports)
+	}
+	return r.smsReports[:limit], nil
+}
+
+func (r *MemoryRepository) UpsertSMSMonthlyReport(_ context.Context, params SMSMonthlyReportRecord) error {
+	for i, rep := range r.smsReports {
+		if rep.TenantID == params.TenantID && rep.YearMonth == params.YearMonth {
+			r.smsReports[i] = params
+			return nil
+		}
+	}
+	r.smsReports = append([]SMSMonthlyReportRecord{params}, r.smsReports...)
+	return nil
+}
+
+func (r *MemoryRepository) MarkSMSReportInvoiceSent(_ context.Context, tenantID string, yearMonth string) error {
+	now := time.Now().UTC()
+	for i, rep := range r.smsReports {
+		if rep.TenantID == tenantID && rep.YearMonth == yearMonth {
+			r.smsReports[i].InvoiceSentAt = &now
+			return nil
+		}
+	}
+	return nil
+}
+
+func (r *MemoryRepository) ListTenantsWithSMSUsage(_ context.Context, yearMonth string) ([]TenantRecord, error) {
+	for _, log := range r.smsLogs {
+		if log.TenantID == r.tenant.ID && log.CreatedAt.Format("2006-01") == yearMonth && r.smsSettings.Enabled {
+			return []TenantRecord{r.tenant}, nil
+		}
+	}
+	return nil, nil
+}

apps/backend/internal/domain/models.go

@@ -132,6 +132,7 @@ type CreateBookingRequest struct {
 	LocationID     *string `json:"locationId,omitempty"`
 	CustomerName   string  `json:"customerName"`
 	CustomerEmail  string  `json:"customerEmail"`
+	CustomerPhone  string  `json:"customerPhone,omitempty"`
 	Notes          string  `json:"notes"`
 	StartsAt       string  `json:"startsAt"`
 	EndsAt         string  `json:"endsAt"`
@@ -146,31 +147,32 @@ type CreateBookingResponse struct {
 type PlanEntitlements struct {
 	MaxLocations      int  `json:"maxLocations"`
 	MaxStaff          int  `json:"maxStaff"`
-	MaxBookingsMonth  int  `json:"maxBookingsMonth"`  // -1 = unlimited
+	MaxBookingsMonth  int  `json:"maxBookingsMonth"` // -1 = unlimited
 	EmailReminders    bool `json:"emailReminders"`
 	AdvancedReporting bool `json:"advancedReporting"`
 	WidgetEmbedding   bool `json:"widgetEmbedding"`
 	UmamiTracking     bool `json:"umamiTracking"`
 	APIAccess         bool `json:"apiAccess"`
 	DedicatedManager  bool `json:"dedicatedManager"`
+	SMSAvailable      bool `json:"smsAvailable"`
 }
 
 type PlanPricing struct {
-	MonthlyAmountCents int    `json:"monthlyAmountCents"`
-	YearlyAmountCents  int    `json:"yearlyAmountCents"`
-	MonthlyFormatted   string `json:"monthlyFormatted"`
-	YearlyFormatted    string `json:"yearlyFormatted"`
-	YearlySavings      string `json:"yearlySavings"`
-	YearlySavingsPercent int  `json:"yearlySavingsPercent"`
+	MonthlyAmountCents   int    `json:"monthlyAmountCents"`
+	YearlyAmountCents    int    `json:"yearlyAmountCents"`
+	MonthlyFormatted     string `json:"monthlyFormatted"`
+	YearlyFormatted      string `json:"yearlyFormatted"`
+	YearlySavings        string `json:"yearlySavings"`
+	YearlySavingsPercent int    `json:"yearlySavingsPercent"`
 }
 
 type PlanDisplayPrice struct {
-	Currency            string `json:"currency"`
-	AmountCents         int    `json:"amountCents"`
-	Formatted           string `json:"formatted"`
-	YearlyAmountCents   int    `json:"yearlyAmountCents,omitempty"`
-	YearlyFormatted     string `json:"yearlyFormatted,omitempty"`
-	YearlySavings       string `json:"yearlySavings,omitempty"`
+	Currency             string `json:"currency"`
+	AmountCents          int    `json:"amountCents"`
+	Formatted            string `json:"formatted"`
+	YearlyAmountCents    int    `json:"yearlyAmountCents,omitempty"`
+	YearlyFormatted      string `json:"yearlyFormatted,omitempty"`
+	YearlySavings        string `json:"yearlySavings,omitempty"`
 	YearlySavingsPercent int    `json:"yearlySavingsPercent,omitempty"`
 }
 
@@ -205,11 +207,11 @@ type CheckoutSessionRequest struct {
 
 type CheckoutLaunchResponse struct {
 	// Stripe checkout
-	CheckoutURL        string            `json:"checkoutUrl,omitempty"`
+	CheckoutURL string `json:"checkoutUrl,omitempty"`
 	// Paddle checkout
-	PriceID            string            `json:"priceId,omitempty"`
-	CustomerID         string            `json:"customerId,omitempty"`
-	CustomerEmail      string            `json:"customerEmail,omitempty"`
+	PriceID       string `json:"priceId,omitempty"`
+	CustomerID    string `json:"customerId,omitempty"`
+	CustomerEmail string `json:"customerEmail,omitempty"`
 	// Common
 	SuccessRedirectURL string            `json:"successRedirectUrl,omitempty"`
 	CancelRedirectURL  string            `json:"cancelRedirectUrl,omitempty"`
@@ -261,19 +263,19 @@ type UpdateLocationRequest struct {
 // ============================================
 
 type BlockedDay struct {
-	ID       string    `json:"id"`
-	TenantID string    `json:"tenantId"`
-	Date     time.Time `json:"date"`
-	Reason   string    `json:"reason"`
-	Type     string    `json:"type"` // full, partial
-	StaffID  *string   `json:"staffId,omitempty"`
+	ID        string    `json:"id"`
+	TenantID  string    `json:"tenantId"`
+	Date      time.Time `json:"date"`
+	Reason    string    `json:"reason"`
+	Type      string    `json:"type"` // full, partial
+	StaffID   *string   `json:"staffId,omitempty"`
 	CreatedAt time.Time `json:"createdAt"`
 }
 
 type CreateBlockedDayRequest struct {
-	Date   string `json:"date" binding:"required"` // RFC3339
-	Reason string `json:"reason" binding:"required"`
-	Type   string `json:"type" binding:"required"` // full, partial
+	Date    string  `json:"date" binding:"required"` // RFC3339
+	Reason  string  `json:"reason" binding:"required"`
+	Type    string  `json:"type" binding:"required"` // full, partial
 	StaffID *string `json:"staffId,omitempty"`
 }
 
@@ -287,32 +289,32 @@ type UpdateBlockedDayRequest struct {
 // ============================================
 
 type Customer struct {
-	ID            string    `json:"id"`
-	TenantID      string    `json:"tenantId"`
-	Name          string    `json:"name"`
-	Email         string    `json:"email"`
-	Phone         *string   `json:"phone,omitempty"`
-	Status        string    `json:"status"` // active, inactive, vip
-	BookingsCount int       `json:"bookingsCount"`
+	ID            string     `json:"id"`
+	TenantID      string     `json:"tenantId"`
+	Name          string     `json:"name"`
+	Email         string     `json:"email"`
+	Phone         *string    `json:"phone,omitempty"`
+	Status        string     `json:"status"` // active, inactive, vip
+	BookingsCount int        `json:"bookingsCount"`
 	LastBookingAt *time.Time `json:"lastBookingAt,omitempty"`
-	CreatedAt     time.Time `json:"createdAt"`
-	Notes         string    `json:"notes,omitempty"`
+	CreatedAt     time.Time  `json:"createdAt"`
+	Notes         string     `json:"notes,omitempty"`
 }
 
 type CreateCustomerRequest struct {
-	Name    string  `json:"name" binding:"required"`
-	Email   string  `json:"email" binding:"required,email"`
-	Phone   *string `json:"phone,omitempty"`
-	Status  string  `json:"status,omitempty"` // defaults to active
-	Notes   string  `json:"notes,omitempty"`
+	Name   string  `json:"name" binding:"required"`
+	Email  string  `json:"email" binding:"required,email"`
+	Phone  *string `json:"phone,omitempty"`
+	Status string  `json:"status,omitempty"` // defaults to active
+	Notes  string  `json:"notes,omitempty"`
 }
 
 type UpdateCustomerRequest struct {
-	Name    string  `json:"name,omitempty"`
-	Email   string  `json:"email,omitempty"`
-	Phone   *string `json:"phone,omitempty"`
-	Status  string  `json:"status,omitempty"`
-	Notes   string  `json:"notes,omitempty"`
+	Name   string  `json:"name,omitempty"`
+	Email  string  `json:"email,omitempty"`
+	Phone  *string `json:"phone,omitempty"`
+	Status string  `json:"status,omitempty"`
+	Notes  string  `json:"notes,omitempty"`
 }
 
 // ============================================
@@ -333,9 +335,9 @@ type CustomerBookingView struct {
 }
 
 type RescheduleBookingRequest struct {
-	NewStartsAt string  `json:"newStartsAt" binding:"required"` // RFC3339
-	NewEndsAt   string  `json:"newEndsAt" binding:"required"`   // RFC3339
-	Reason      string  `json:"reason,omitempty"`
+	NewStartsAt string `json:"newStartsAt" binding:"required"` // RFC3339
+	NewEndsAt   string `json:"newEndsAt" binding:"required"`   // RFC3339
+	Reason      string `json:"reason,omitempty"`
 }
 
 type CancelBookingRequest struct {
@@ -347,35 +349,35 @@ type CancelBookingRequest struct {
 // ============================================
 
 type AdminDashboardStats struct {
-	TotalTenants         int64 `json:"totalTenants"`
-	TotalUsers           int64 `json:"totalUsers"`
-	ActiveSubscriptions  int64 `json:"activeSubscriptions"`
-	TrialSubscriptions   int64 `json:"trialSubscriptions"`
-	BookingsThisMonth    int64 `json:"bookingsThisMonth"`
+	TotalTenants          int64 `json:"totalTenants"`
+	TotalUsers            int64 `json:"totalUsers"`
+	ActiveSubscriptions   int64 `json:"activeSubscriptions"`
+	TrialSubscriptions    int64 `json:"trialSubscriptions"`
+	BookingsThisMonth     int64 `json:"bookingsThisMonth"`
 	RevenueThisMonthCents int64 `json:"revenueThisMonthCents"`
 }
 
 type AdminTenantList struct {
-	Total    int            `json:"total"`
-	Page     int            `json:"page"`
-	PageSize int            `json:"pageSize"`
-	Tenants  []AdminTenant  `json:"tenants"`
+	Total    int           `json:"total"`
+	Page     int           `json:"page"`
+	PageSize int           `json:"pageSize"`
+	Tenants  []AdminTenant `json:"tenants"`
 }
 
 type AdminTenant struct {
-	ID                string `json:"id"`
-	Slug              string `json:"slug"`
-	Name              string `json:"name"`
-	PlanCode          string `json:"planCode"`
+	ID                 string `json:"id"`
+	Slug               string `json:"slug"`
+	Name               string `json:"name"`
+	PlanCode           string `json:"planCode"`
 	SubscriptionStatus string `json:"subscriptionStatus"`
-	BillingProvider   string `json:"billingProvider"`
+	BillingProvider    string `json:"billingProvider"`
 }
 
 type AdminUserList struct {
-	Total    int          `json:"total"`
-	Page     int          `json:"page"`
-	PageSize int          `json:"pageSize"`
-	Users    []AdminUser  `json:"users"`
+	Total    int         `json:"total"`
+	Page     int         `json:"page"`
+	PageSize int         `json:"pageSize"`
+	Users    []AdminUser `json:"users"`
 }
 
 type AdminUser struct {
@@ -421,7 +423,7 @@ type UpdateWorkingHoursRequest struct {
 type EmailTemplate struct {
 	ID        string `json:"id"`
 	TenantID  string `json:"tenantId"`
-	Type      string `json:"type"`      // booking_confirmation, reminder, cancellation, etc.
+	Type      string `json:"type"` // booking_confirmation, reminder, cancellation, etc.
 	Subject   string `json:"subject"`
 	BodyHTML  string `json:"bodyHtml"`
 	BodyText  string `json:"bodyText"`
@@ -436,14 +438,69 @@ type SendEmailRequest struct {
 }
 
 type EmailNotification struct {
-	ID        string    `json:"id"`
-	TenantID  string    `json:"tenantId"`
-	BookingID string    `json:"bookingId,omitempty"`
-	Channel   string    `json:"channel"` // email, sms
-	Type      string    `json:"type"`    // confirmation, reminder, cancellation
-	Recipient string    `json:"recipient"`
-	Status    string    `json:"status"`  // pending, sent, failed
+	ID        string     `json:"id"`
+	TenantID  string     `json:"tenantId"`
+	BookingID string     `json:"bookingId,omitempty"`
+	Channel   string     `json:"channel"` // email, sms
+	Type      string     `json:"type"`    // confirmation, reminder, cancellation
+	Recipient string     `json:"recipient"`
+	Status    string     `json:"status"` // pending, sent, failed
 	SentAt    *time.Time `json:"sentAt,omitempty"`
-	Error     string    `json:"error,omitempty"`
-	CreatedAt time.Time `json:"createdAt"`
+	Error     string     `json:"error,omitempty"`
+	CreatedAt time.Time  `json:"createdAt"`
+}
+
+// ============================================
+// SMS MODELS
+// ============================================
+
+type SMSSettings struct {
+	Enabled        bool   `json:"enabled"`
+	SenderName     string `json:"senderName,omitempty"`
+	MonthlyLimit   int    `json:"monthlyLimit,omitempty"`
+	MessagesSent   int    `json:"messagesSent"`
+	TotalCostCents int    `json:"totalCostCents"`
+	Available      bool   `json:"available"`
+}
+
+type UpdateSMSSettingsRequest struct {
+	Enabled      bool   `json:"enabled"`
+	SenderName   string `json:"senderName,omitempty"`
+	MonthlyLimit int    `json:"monthlyLimit,omitempty"`
+}
+
+type SendSMSRequest struct {
+	To   string `json:"to" binding:"required"`
+	Body string `json:"body" binding:"required,max=1000"`
+}
+
+type SendSMSResponse struct {
+	LogID     string `json:"logId"`
+	MessageID string `json:"messageId,omitempty"`
+	RequestID string `json:"requestId,omitempty"`
+	Status    string `json:"status"`
+	CostCents int    `json:"costCents"`
+}
+
+type SMSUsageLog struct {
+	ID             string    `json:"id"`
+	RecipientPhone string    `json:"recipientPhone"`
+	MessageBody    string    `json:"messageBody,omitempty"`
+	Status         string    `json:"status"`
+	CostCents      int       `json:"costCents"`
+	CreatedAt      time.Time `json:"createdAt"`
+}
+
+type SMSUsageReport struct {
+	YearMonth       string     `json:"yearMonth"`
+	MessageCount    int        `json:"messageCount"`
+	TotalCostCents  int        `json:"totalCostCents"`
+	StripeInvoiceID string     `json:"stripeInvoiceId,omitempty"`
+	InvoiceSentAt   *time.Time `json:"invoiceSentAt,omitempty"`
+}
+
+type SMSInvoiceBatchResponse struct {
+	YearMonth      string `json:"yearMonth"`
+	ProcessedCount int    `json:"processedCount"`
+	FailedCount    int    `json:"failedCount"`
 }

apps/backend/internal/notifications/email_templates.go

@@ -458,3 +458,93 @@ func RenderReminderEmail(from string, job db.ReminderJobRecord) EmailMessage {
 	}
 	return RenderEmailMessage(data)
 }
+
+// ============================================
+// SMS USAGE EMAIL TEMPLATE
+// ============================================
+
+type SMSUsageEmailData struct {
+	TenantName     string
+	TenantSlug     string
+	BusinessEmail  string
+	YearMonth      string
+	MessageCount   int
+	TotalCostCents int
+	Locale         string
+}
+
+func RenderSMSUsageEmail(data SMSUsageEmailData) EmailMessage {
+	cs := data.Locale == "cs"
+	year := data.YearMonth[:4]
+	month := data.YearMonth[5:]
+	monthLabel := month + "/" + year
+	if cs {
+		monthLabel = month + "." + year
+	}
+
+	totalFormatted := fmt.Sprintf("%.2f Kč", float64(data.TotalCostCents)/100.0)
+
+	subject := fmt.Sprintf("Bookra SMS Usage - %s (%s)", monthLabel, totalFormatted)
+	if cs {
+		subject = fmt.Sprintf("Bookra SMS Přehled - %s (%s)", monthLabel, totalFormatted)
+	}
+
+	textBody := fmt.Sprintf(
+		"SMS Usage Summary for %s\n\nPeriod: %s\nMessages sent: %d\nTotal cost: %s\n\nThis amount will be added to your next invoice.",
+		data.TenantName, monthLabel, data.MessageCount, totalFormatted,
+	)
+	if cs {
+		textBody = fmt.Sprintf(
+			"Přehled SMS pro %s\n\nObdobí: %s\nOdeslaných zpráv: %d\nCelková cena: %s\n\nTato částka bude přidána k vaší další faktuře.",
+			data.TenantName, monthLabel, data.MessageCount, totalFormatted,
+		)
+	}
+
+	htmlBody := fmt.Sprintf(`<!DOCTYPE html>
+<html>
+<head><meta charset="utf-8"><meta name="viewport" content="width=device-width,initial-scale=1"></head>
+<body style="font-family:-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,sans-serif;max-width:600px;margin:0 auto;padding:20px;color:#1f2937;">
+<div style="text-align:center;margin-bottom:24px;"><span style="font-size:32px;">📱</span></div>
+<h2 style="text-align:center;color:#1f2937;margin-bottom:16px;">%s</h2>
+<p style="color:#6b7280;text-align:center;margin-bottom:24px;">%s</p>
+<table style="width:100%%;border-collapse:collapse;margin-bottom:24px;">
+<tr style="border-bottom:1px solid #e5e7eb;">
+<td style="padding:12px 0;color:#6b7280;">%s</td>
+<td style="padding:12px 0;text-align:right;font-weight:600;">%s</td>
+</tr>
+<tr style="border-bottom:1px solid #e5e7eb;">
+<td style="padding:12px 0;color:#6b7280;">%s</td>
+<td style="padding:12px 0;text-align:right;font-weight:600;">%d</td>
+</tr>
+<tr>
+<td style="padding:12px 0;color:#1f2937;font-weight:600;">%s</td>
+<td style="padding:12px 0;text-align:right;font-weight:700;font-size:18px;">%s</td>
+</tr>
+</table>
+<p style="color:#9ca3af;font-size:14px;text-align:center;">%s</p>
+<hr style="border:none;border-top:1px solid #e5e7eb;margin:24px 0;">
+<p style="color:#9ca3af;font-size:12px;text-align:center;">Powered by <a href="https://bookra.eu" style="color:#4f46e5;">Bookra</a></p>
+</body></html>`,
+		ifCS(cs, "SMS Usage Summary", "Přehled SMS využití"),
+		fmt.Sprintf(ifCS(cs, "Your SMS usage for %s", "Vaše SMS využití za %s"), data.TenantName),
+		ifCS(cs, "Period", "Období"), monthLabel,
+		ifCS(cs, "Messages sent", "Odeslaných zpráv"), data.MessageCount,
+		ifCS(cs, "Total cost (excl. VAT)", "Celková cena (bez DPH)"), totalFormatted,
+		ifCS(cs, "This amount will be added to your next Stripe invoice.", "Tato částka bude přidána k vaší další faktuře Stripe."),
+	)
+
+	return EmailMessage{
+		From:    "",
+		To:      data.BusinessEmail,
+		Subject: subject,
+		Text:    textBody,
+		HTML:    htmlBody,
+	}
+}
+
+func ifCS(cs bool, en, csText string) string {
+	if cs {
+		return csText
+	}
+	return en
+}

apps/backend/internal/notifications/service.go

@@ -334,6 +334,14 @@ func (s *Service) SendUsageWarning(ctx context.Context, tenantID string, locatio
 	return err
 }
 
+// SendRawEmail sends a pre-built email message
+func (s *Service) SendRawEmail(ctx context.Context, msg EmailMessage) (DeliveryReceipt, error) {
+	if msg.From == "" {
+		msg.From = s.cfg.EmailFrom
+	}
+	return s.emailProvider.Send(ctx, msg)
+}
+
 func (s *Service) SendTrialEndingEmail(ctx context.Context, tenantID string, daysRemaining int) error {
 	tenant, err := s.repo.GetTenantByID(ctx, tenantID)
 	if err != nil {

apps/backend/internal/sms/billing.go

@@ -0,0 +1,80 @@
+package sms
+
+import (
+	"context"
+	"fmt"
+	"strings"
+
+	"bookra/apps/backend/internal/config"
+	"bookra/apps/backend/internal/db"
+
+	"github.com/stripe/stripe-go/v81"
+	"github.com/stripe/stripe-go/v81/invoiceitem"
+)
+
+type BillingService struct {
+	cfg         config.Config
+	repo        db.Repository
+	smsPriceIDs map[string]string // currency -> price ID
+}
+
+func NewBillingService(cfg config.Config, repo db.Repository) *BillingService {
+	return &BillingService{
+		cfg:         cfg,
+		repo:        repo,
+		smsPriceIDs: cfg.StripeSMSPriceMatrix,
+	}
+}
+
+// PriceIDForCurrency returns the Stripe price ID for SMS in the given currency
+func (b *BillingService) PriceIDForCurrency(currency string) string {
+	c := strings.ToLower(strings.TrimSpace(currency))
+	if c == "" {
+		c = "czk"
+	}
+	if id := b.smsPriceIDs[c]; id != "" {
+		return id
+	}
+	// Fallback to CZK
+	return b.smsPriceIDs["czk"]
+}
+
+// CreateMonthlyInvoiceItem creates a Stripe InvoiceItem for the total SMS usage of a month.
+// This adds a line item to the customer's next invoice — charging all messages together.
+func (b *BillingService) CreateMonthlyInvoiceItem(ctx context.Context, customerID string, currency string, yearMonth string, messageCount int, totalCents int) (string, error) {
+	if customerID == "" {
+		return "", fmt.Errorf("customer id is empty")
+	}
+
+	priceID := b.PriceIDForCurrency(currency)
+	c := strings.ToLower(strings.TrimSpace(currency))
+	if c == "" {
+		c = "czk"
+	}
+
+	// If a Stripe price is configured, use Price + Quantity for a clean invoice line
+	if priceID != "" {
+		item, err := invoiceitem.New(&stripe.InvoiceItemParams{
+			Customer:    stripe.String(customerID),
+			Price:       stripe.String(priceID),
+			Quantity:    stripe.Int64(int64(messageCount)),
+			Description: stripe.String(fmt.Sprintf("SMS Messages (%s) — %d messages", yearMonth, messageCount)),
+		})
+		if err != nil {
+			return "", fmt.Errorf("failed to create invoice item: %w", err)
+		}
+		return item.ID, nil
+	}
+
+	// Fallback: explicit amount (for dev/testing when no price configured yet)
+	item, err := invoiceitem.New(&stripe.InvoiceItemParams{
+		Customer:    stripe.String(customerID),
+		Amount:      stripe.Int64(int64(totalCents)),
+		Currency:    stripe.String(c),
+		Description: stripe.String(fmt.Sprintf("SMS Messages (%s) — %d messages", yearMonth, messageCount)),
+	})
+	if err != nil {
+		return "", fmt.Errorf("failed to create invoice item: %w", err)
+	}
+	return item.ID, nil
+}

apps/backend/internal/sms/service.go

@@ -0,0 +1,461 @@
+package sms
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"strings"
+	"time"
+
+	"bookra/apps/backend/internal/config"
+	"bookra/apps/backend/internal/db"
+	"bookra/apps/backend/internal/domain"
+	"bookra/apps/backend/internal/notifications"
+	"bookra/apps/backend/internal/shared"
+)
+
+var (
+	ErrSMSNotConfigured     = errors.New("sms is not configured")
+	ErrSMSNotEnabled        = errors.New("sms is not enabled for this tenant")
+	ErrSMSPlanNotAllowed    = errors.New("sms is only available on pro and business plans")
+	ErrSMSLimitReached      = errors.New("monthly sms limit reached")
+	ErrSMSInvalidPhone      = errors.New("invalid phone number")
+	ErrSMSMissingAPIKey     = errors.New("sms manager api key is missing")
+	ErrSMSSendFailed        = errors.New("sms send failed")
+	ErrStripeNotConfigured  = errors.New("stripe is not configured for sms billing")
+	ErrNoActiveSubscription = errors.New("no active subscription for sms billing")
+)
+
+const smsCostCents = 150 // 1.50 CZK
+
+type Service struct {
+	cfg     config.Config
+	repo    db.Repository
+	billing *BillingService
+	client  *http.Client
+	baseURL string
+	apiKey  string
+}
+
+func NewService(cfg config.Config, repo db.Repository) *Service {
+	s := &Service{
+		cfg:     cfg,
+		repo:    repo,
+		client:  &http.Client{Timeout: 15 * time.Second},
+		baseURL: strings.TrimRight(cfg.SMSManagerBaseURL, "/"),
+		apiKey:  cfg.SMSManagerAPIKey,
+	}
+	if cfg.StripeConfigured() && cfg.StripeSMSConfigured() {
+		s.billing = NewBillingService(cfg, repo)
+	}
+	return s
+}
+
+func (s *Service) Enabled() bool {
+	return s.cfg.SMSConfigured()
+}
+
+func (s *Service) IsAvailable(ctx context.Context, tenantID string) (bool, error) {
+	if !s.Enabled() {
+		return false, nil
+	}
+	settings, err := s.repo.GetTenantSMSSettings(ctx, tenantID)
+	if err != nil {
+		return false, err
+	}
+	return settings.Enabled, nil
+}
+
+func (s *Service) canUseSMS(ctx context.Context, tenantID string) error {
+	if !s.Enabled() {
+		return ErrSMSNotConfigured
+	}
+
+	tenant, err := s.repo.GetTenantByID(ctx, tenantID)
+	if err != nil {
+		return err
+	}
+
+	plan := shared.NormalizePlanCode(tenant.PlanCode)
+	if plan != "pro" && plan != "business" {
+		return ErrSMSPlanNotAllowed
+	}
+
+	if tenant.SubscriptionStatus != "active" && tenant.SubscriptionStatus != "trialing" {
+		return ErrNoActiveSubscription
+	}
+
+	settings, err := s.repo.GetTenantSMSSettings(ctx, tenantID)
+	if err != nil {
+		return err
+	}
+	if !settings.Enabled {
+		return ErrSMSNotEnabled
+	}
+
+	return nil
+}
+
+func (s *Service) GetSettings(ctx context.Context, tenantID string) (domain.SMSSettings, error) {
+	settings, err := s.repo.GetTenantSMSSettings(ctx, tenantID)
+	if err != nil {
+		return domain.SMSSettings{}, err
+	}
+
+	usage, err := s.repo.GetSMSUsageThisMonth(ctx, tenantID)
+	if err != nil {
+		return domain.SMSSettings{}, err
+	}
+
+	return domain.SMSSettings{
+		Enabled:        settings.Enabled,
+		SenderName:     settings.SenderName,
+		MonthlyLimit:   settings.MonthlyLimit,
+		MessagesSent:   usage.MessageCount,
+		TotalCostCents: usage.TotalCostCents,
+		Available:      s.Enabled(),
+	}, nil
+}
+
+func (s *Service) UpdateSettings(ctx context.Context, tenantID string, req domain.UpdateSMSSettingsRequest) (domain.SMSSettings, error) {
+	tenant, err := s.repo.GetTenantByID(ctx, tenantID)
+	if err != nil {
+		return domain.SMSSettings{}, err
+	}
+
+	plan := shared.NormalizePlanCode(tenant.PlanCode)
+	if plan != "pro" && plan != "business" {
+		return domain.SMSSettings{}, ErrSMSPlanNotAllowed
+	}
+
+	if tenant.SubscriptionStatus != "active" && tenant.SubscriptionStatus != "trialing" {
+		return domain.SMSSettings{}, ErrNoActiveSubscription
+	}
+
+	if err := s.repo.UpsertTenantSMSSettings(ctx, db.TenantSMSSettingsRecord{
+		TenantID:     tenantID,
+		Enabled:      req.Enabled,
+		SenderName:   strings.TrimSpace(req.SenderName),
+		MonthlyLimit: req.MonthlyLimit,
+	}); err != nil {
+		return domain.SMSSettings{}, err
+	}
+
+	return s.GetSettings(ctx, tenantID)
+}
+
+func (s *Service) SendMessage(ctx context.Context, tenantID string, req domain.SendSMSRequest) (domain.SendSMSResponse, error) {
+	if err := s.canUseSMS(ctx, tenantID); err != nil {
+		return domain.SendSMSResponse{}, err
+	}
+
+	phone := normalizePhone(req.To)
+	if phone == "" {
+		return domain.SendSMSResponse{}, ErrSMSInvalidPhone
+	}
+
+	// Check monthly limit
+	settings, err := s.repo.GetTenantSMSSettings(ctx, tenantID)
+	if err != nil {
+		return domain.SendSMSResponse{}, err
+	}
+	if settings.MonthlyLimit > 0 {
+		usage, err := s.repo.GetSMSUsageThisMonth(ctx, tenantID)
+		if err != nil {
+			return domain.SendSMSResponse{}, err
+		}
+		if usage.MessageCount >= settings.MonthlyLimit {
+			return domain.SendSMSResponse{}, ErrSMSLimitReached
+		}
+	}
+
+	// Send via SMS Manager
+	resp, err := s.sendToSMSManager(ctx, phone, req.Body, settings.SenderName)
+	if err != nil {
+		return domain.SendSMSResponse{}, err
+	}
+
+	// Extract message ID from accepted recipients
+	messageID := ""
+	if len(resp.Accepted) > 0 {
+		messageID = resp.Accepted[0].MessageID
+	}
+
+	// Log usage locally (Stripe billing happens once at month-end)
+	logID, err := s.repo.CreateSMSUsageLog(ctx, db.SMSUsageLogRecord{
+		TenantID:          tenantID,
+		RecipientPhone:    phone,
+		MessageBody:       req.Body,
+		ExternalMessageID: messageID,
+		ExternalRequestID: resp.RequestID,
+		Status:            "sent",
+		CostCents:         smsCostCents,
+		SentAt:            time.Now().UTC(),
+	})
+	if err != nil {
+		return domain.SendSMSResponse{}, fmt.Errorf("failed to log sms usage: %w", err)
+	}
+
+	return domain.SendSMSResponse{
+		LogID:     logID,
+		MessageID: messageID,
+		RequestID: resp.RequestID,
+		Status:    "sent",
+		CostCents: smsCostCents,
+	}, nil
+}
+
+func (s *Service) GetUsage(ctx context.Context, tenantID string, yearMonth string) (domain.SMSUsageReport, error) {
+	report, err := s.repo.GetSMSUsageForMonth(ctx, tenantID, yearMonth)
+	if err != nil {
+		return domain.SMSUsageReport{}, err
+	}
+	return domain.SMSUsageReport{
+		YearMonth:      report.YearMonth,
+		MessageCount:   report.MessageCount,
+		TotalCostCents: report.TotalCostCents,
+	}, nil
+}
+
+func (s *Service) GetUsageHistory(ctx context.Context, tenantID string, limit int) ([]domain.SMSUsageLog, error) {
+	if limit <= 0 {
+		limit = 50
+	}
+	records, err := s.repo.ListSMSUsageLogs(ctx, tenantID, limit)
+	if err != nil {
+		return nil, err
+	}
+
+	logs := make([]domain.SMSUsageLog, len(records))
+	for i, r := range records {
+		logs[i] = domain.SMSUsageLog{
+			ID:             r.ID,
+			RecipientPhone: r.RecipientPhone,
+			MessageBody:    r.MessageBody,
+			Status:         r.Status,
+			CostCents:      r.CostCents,
+			CreatedAt:      r.CreatedAt,
+		}
+	}
+	return logs, nil
+}
+
+func (s *Service) GetMonthlyReports(ctx context.Context, tenantID string, limit int) ([]domain.SMSUsageReport, error) {
+	if limit <= 0 {
+		limit = 12
+	}
+	records, err := s.repo.ListSMSMonthlyReports(ctx, tenantID, limit)
+	if err != nil {
+		return nil, err
+	}
+
+	reports := make([]domain.SMSUsageReport, len(records))
+	for i, r := range records {
+		reports[i] = domain.SMSUsageReport{
+			YearMonth:       r.YearMonth,
+			MessageCount:    r.MessageCount,
+			TotalCostCents:  r.TotalCostCents,
+			StripeInvoiceID: r.StripeInvoiceID,
+			InvoiceSentAt:   r.InvoiceSentAt,
+		}
+	}
+	return reports, nil
+}
+
+// GenerateMonthlyInvoices creates/finalizes monthly invoices for SMS usage
+func (s *Service) GenerateMonthlyInvoices(ctx context.Context, yearMonth string, notificationSvc *notifications.Service) (domain.SMSInvoiceBatchResponse, error) {
+	if yearMonth == "" {
+		now := time.Now().UTC()
+		yearMonth = fmt.Sprintf("%04d-%02d", now.Year(), now.Month())
+	}
+
+	response := domain.SMSInvoiceBatchResponse{YearMonth: yearMonth}
+
+	// Get all tenants with SMS enabled that have usage this month
+	tenants, err := s.repo.ListTenantsWithSMSUsage(ctx, yearMonth)
+	if err != nil {
+		return response, err
+	}
+
+	for _, t := range tenants {
+		report, err := s.repo.GetSMSUsageForMonth(ctx, t.ID, yearMonth)
+		if err != nil {
+			response.FailedCount++
+			continue
+		}
+
+		if report.MessageCount == 0 {
+			continue
+		}
+
+		// Create Stripe InvoiceItem for total monthly SMS usage
+		// This adds one line to the customer's next invoice: all messages together
+		stripeInvoiceItemID := ""
+		if s.billing != nil {
+			customerID := ""
+			if t.BillingCustomerID != nil {
+				customerID = *t.BillingCustomerID
+			}
+			if customerID != "" {
+				currency := "czk"
+				if t.BillingProvider != "" {
+					// Try to infer currency from billing snapshot if available
+					snap, _ := s.repo.GetSubscriptionSnapshot(ctx, t.ID)
+					if snap.Currency != "" {
+						currency = snap.Currency
+					}
+				}
+				itemID, err := s.billing.CreateMonthlyInvoiceItem(ctx, customerID, currency, yearMonth, report.MessageCount, report.TotalCostCents)
+				if err == nil {
+					stripeInvoiceItemID = itemID
+				}
+			}
+		}
+
+		if err := s.repo.UpsertSMSMonthlyReport(ctx, db.SMSMonthlyReportRecord{
+			TenantID:        t.ID,
+			YearMonth:       yearMonth,
+			MessageCount:    report.MessageCount,
+			TotalCostCents:  report.TotalCostCents,
+			StripeInvoiceID: stripeInvoiceItemID,
+		}); err != nil {
+			response.FailedCount++
+			continue
+		}
+
+		// Send usage summary email
+		if notificationSvc != nil {
+			_ = s.sendUsageSummaryEmail(ctx, t, report, notificationSvc)
+		}
+
+		response.ProcessedCount++
+	}
+
+	return response, nil
+}
+
+func (s *Service) sendUsageSummaryEmail(ctx context.Context, tenant db.TenantRecord, report db.SMSMonthlyReportRecord, svc *notifications.Service) error {
+	// Get brand profile for email styling
+	brand, _ := s.repo.GetBrandProfile(ctx, tenant.ID)
+
+	data := notifications.SMSUsageEmailData{
+		TenantName:     brand.Name,
+		TenantSlug:     tenant.Slug,
+		BusinessEmail:  "",
+		YearMonth:      report.YearMonth,
+		MessageCount:   report.MessageCount,
+		TotalCostCents: report.TotalCostCents,
+		Locale:         tenant.Locale,
+	}
+
+	// Find owner email
+	membership, err := s.repo.GetTenantMembershipByUserID(ctx, tenant.ID)
+	if err == nil {
+		user, err := s.repo.GetUserByID(ctx, membership.UserID)
+		if err == nil {
+			data.BusinessEmail = user.Email
+		}
+	}
+
+	if data.BusinessEmail == "" {
+		return errors.New("no business email found")
+	}
+
+	msg := notifications.RenderSMSUsageEmail(data)
+	_, err = svc.SendRawEmail(ctx, msg)
+	if err == nil {
+		_ = s.repo.MarkSMSReportInvoiceSent(ctx, report.TenantID, report.YearMonth)
+	}
+	return err
+}
+
+// --- SMS Manager API client ---
+
+type smsManagerMessage struct {
+	Body string `json:"body"`
+	To   []struct {
+		PhoneNumber string `json:"phone_number"`
+	} `json:"to"`
+	Tag string `json:"tag,omitempty"`
+}
+
+type smsManagerResponse struct {
+	RequestID string `json:"request_id"`
+	Accepted  []struct {
+		Key       string `json:"key"`
+		MessageID string `json:"message_id"`
+	} `json:"accepted"`
+	Rejected []struct {
+		Key     string `json:"key"`
+		Message string `json:"message,omitempty"`
+	} `json:"rejected"`
+}
+
+func (s *Service) sendToSMSManager(ctx context.Context, phone, body, senderName string) (smsManagerResponse, error) {
+	if s.apiKey == "" {
+		return smsManagerResponse{}, ErrSMSMissingAPIKey
+	}
+
+	payload := smsManagerMessage{
+		Body: body,
+		To: []struct {
+			PhoneNumber string `json:"phone_number"`
+		}{{PhoneNumber: phone}},
+		Tag: "transactional",
+	}
+
+	jsonBody, err := json.Marshal(payload)
+	if err != nil {
+		return smsManagerResponse{}, err
+	}
+
+	req, err := http.NewRequestWithContext(ctx, "POST", s.baseURL+"/message", bytes.NewReader(jsonBody))
+	if err != nil {
+		return smsManagerResponse{}, err
+	}
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("x-api-key", s.apiKey)
+
+	resp, err := s.client.Do(req)
+	if err != nil {
+		return smsManagerResponse{}, err
+	}
+	defer resp.Body.Close()
+
+	respBody, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return smsManagerResponse{}, err
+	}
+
+	if resp.StatusCode != http.StatusOK {
+		return smsManagerResponse{}, fmt.Errorf("%w: status=%d body=%s", ErrSMSSendFailed, resp.StatusCode, string(respBody))
+	}
+
+	var result smsManagerResponse
+	if err := json.Unmarshal(respBody, &result); err != nil {
+		return smsManagerResponse{}, err
+	}
+
+	if len(result.Rejected) > 0 && len(result.Accepted) == 0 {
+		return result, fmt.Errorf("%w: %v", ErrSMSSendFailed, result.Rejected)
+	}
+
+	return result, nil
+}
+
+func normalizePhone(phone string) string {
+	p := strings.TrimSpace(phone)
+	p = strings.ReplaceAll(p, " ", "")
+	p = strings.ReplaceAll(p, "-", "")
+	p = strings.TrimPrefix(p, "+")
+	p = strings.TrimPrefix(p, "00")
+	// Czech default if no country code and 9 digits
+	if len(p) == 9 {
+		p = "420" + p
+	}
+	return p
+}

apps/backend/internal/sms/service_test.go

@@ -0,0 +1,91 @@
+package sms
+
+import (
+	"context"
+	"testing"
+
+	"bookra/apps/backend/internal/config"
+	"bookra/apps/backend/internal/db"
+	"bookra/apps/backend/internal/domain"
+)
+
+func TestSMSServiceEnabled(t *testing.T) {
+	cfg := config.Config{SMSManagerAPIKey: "test-key"}
+	svc := NewService(cfg, db.NewMemoryRepository())
+	if !svc.Enabled() {
+		t.Fatal("expected SMS service to be enabled")
+	}
+}
+
+func TestSMSServiceDisabledWithoutKey(t *testing.T) {
+	cfg := config.Config{}
+	svc := NewService(cfg, db.NewMemoryRepository())
+	if svc.Enabled() {
+		t.Fatal("expected SMS service to be disabled")
+	}
+}
+
+func TestGetSettingsForNewTenant(t *testing.T) {
+	cfg := config.Config{SMSManagerAPIKey: "test-key"}
+	repo := db.NewMemoryRepository()
+	svc := NewService(cfg, repo)
+
+	ctx := context.Background()
+	// Use the default tenant ID from memory repository
+	settings, err := svc.GetSettings(ctx, "5d6b3551-0a3e-4b86-bdf0-e9df20a47148")
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if settings.Enabled {
+		t.Fatal("expected SMS to be disabled by default")
+	}
+	if !settings.Available {
+		t.Fatal("expected SMS to be available when configured")
+	}
+}
+
+func TestUpdateSettingsRequiresProOrBusiness(t *testing.T) {
+	cfg := config.Config{SMSManagerAPIKey: "test-key"}
+	repo := db.NewMemoryRepository()
+	svc := NewService(cfg, repo)
+
+	ctx := context.Background()
+	// Memory repo tenant is "pro" by default. Change to starter by modifying tenant.
+	_, err := svc.UpdateSettings(ctx, "5d6b3551-0a3e-4b86-bdf0-e9df20a47148", domain.UpdateSMSSettingsRequest{Enabled: true})
+	// The memory repo tenant is "pro", so this should succeed
+	if err != nil {
+		t.Fatalf("unexpected error for pro tenant: %v", err)
+	}
+}
+
+func TestSendMessageRequiresEnabledSMS(t *testing.T) {
+	cfg := config.Config{SMSManagerAPIKey: "test-key"}
+	repo := db.NewMemoryRepository()
+	svc := NewService(cfg, repo)
+
+	ctx := context.Background()
+	_, err := svc.SendMessage(ctx, "5d6b3551-0a3e-4b86-bdf0-e9df20a47148", domain.SendSMSRequest{To: "+420777123456", Body: "Hello"})
+	if err != ErrSMSNotEnabled {
+		t.Fatalf("expected ErrSMSNotEnabled, got: %v", err)
+	}
+}
+
+func TestNormalizePhone(t *testing.T) {
+	tests := []struct {
+		input    string
+		expected string
+	}{
+		{"+420 777 123 456", "420777123456"},
+		{"420777123456", "420777123456"},
+		{"777123456", "420777123456"},
+		{" 777-123-456 ", "420777123456"},
+		{"+49 151 12345678", "4915112345678"},
+	}
+
+	for _, tc := range tests {
+		result := normalizePhone(tc.input)
+		if result != tc.expected {
+			t.Errorf("normalizePhone(%q) = %q, want %q", tc.input, result, tc.expected)
+		}
+	}
+}

apps/backend/internal/tenancy/service.go

@@ -31,6 +31,10 @@ func NewService(repo db.Repository) *Service {
 	return &Service{repo: repo}
 }
 
+func (s *Service) GetTenantMembership(ctx context.Context, principal domain.Principal) (db.TenantMembershipRecord, error) {
+	return s.repo.GetTenantMembershipByUserID(ctx, principal.Subject)
+}
+
 func (s *Service) Bootstrap(ctx context.Context, principal domain.Principal) (domain.TenantBootstrap, error) {
 	membership, err := s.repo.GetTenantMembershipByUserID(ctx, principal.Subject)
 	if err != nil {

apps/backend/migrations/00008_sms.sql

@@ -0,0 +1,47 @@
+-- +goose Up
+CREATE TABLE IF NOT EXISTS tenant_sms_settings (
+  tenant_id uuid PRIMARY KEY REFERENCES tenants(id) ON DELETE CASCADE,
+  enabled boolean NOT NULL DEFAULT false,
+  sender_name text NOT NULL DEFAULT '',
+  monthly_limit integer,
+  stripe_subscription_item_id text,
+  created_at timestamptz NOT NULL DEFAULT now(),
+  updated_at timestamptz NOT NULL DEFAULT now()
+);
+
+CREATE TABLE IF NOT EXISTS sms_usage_logs (
+  id uuid PRIMARY KEY DEFAULT gen_random_uuid(),
+  tenant_id uuid NOT NULL REFERENCES tenants(id) ON DELETE CASCADE,
+  recipient_phone text NOT NULL,
+  message_body text NOT NULL,
+  external_message_id text,
+  external_request_id text,
+  status text NOT NULL DEFAULT 'pending',
+  cost_cents integer NOT NULL DEFAULT 150,
+  sent_at timestamptz,
+  created_at timestamptz NOT NULL DEFAULT now()
+);
+
+CREATE TABLE IF NOT EXISTS sms_monthly_reports (
+  id uuid PRIMARY KEY DEFAULT gen_random_uuid(),
+  tenant_id uuid NOT NULL REFERENCES tenants(id) ON DELETE CASCADE,
+  year_month text NOT NULL,
+  message_count integer NOT NULL DEFAULT 0,
+  total_cost_cents integer NOT NULL DEFAULT 0,
+  stripe_invoice_id text,
+  invoice_sent_at timestamptz,
+  created_at timestamptz NOT NULL DEFAULT now(),
+  UNIQUE (tenant_id, year_month)
+);
+
+CREATE INDEX IF NOT EXISTS idx_sms_usage_tenant_month ON sms_usage_logs (tenant_id, date_trunc('month', created_at));
+CREATE INDEX IF NOT EXISTS idx_sms_usage_tenant_created ON sms_usage_logs (tenant_id, created_at DESC);
+CREATE INDEX IF NOT EXISTS idx_sms_reports_tenant ON sms_monthly_reports (tenant_id, year_month DESC);
+
+-- +goose Down
+DROP INDEX IF EXISTS idx_sms_reports_tenant;
+DROP INDEX IF EXISTS idx_sms_usage_tenant_created;
+DROP INDEX IF EXISTS idx_sms_usage_tenant_month;
+DROP TABLE IF EXISTS sms_monthly_reports;
+DROP TABLE IF EXISTS sms_usage_logs;
+DROP TABLE IF EXISTS tenant_sms_settings;

apps/backend/migrations/00009_booking_phone.sql

@@ -0,0 +1,5 @@
+-- +goose Up
+ALTER TABLE bookings ADD COLUMN IF NOT EXISTS customer_phone text;
+
+-- +goose Down
+ALTER TABLE bookings DROP COLUMN IF EXISTS customer_phone;