Building out notification update channels

.gitignore

@@ -42,3 +42,4 @@ Prompts/
 
 # Logs
 *.log
+.claude

backend-go/.env.example

@@ -14,3 +14,7 @@ POLL_INTERVAL_MS=60000
 
 # Firebase
 FIREBASE_PROJECT_ID=koin-ping
+
+# Email notifications (Resend — https://resend.com)
+# RESEND_API_KEY=re_xxxxxxxxxxxx
+# EMAIL_FROM=Koin Ping <alerts@yourdomain.com>

backend-go/cmd/api/main.go

@@ -14,6 +14,7 @@ import (
 	"github.com/kjannette/koin-ping/backend-go/internal/handlers"
 	"github.com/kjannette/koin-ping/backend-go/internal/middleware"
 	"github.com/kjannette/koin-ping/backend-go/internal/models"
+	"github.com/kjannette/koin-ping/backend-go/internal/services"
 )
 
 const (
@@ -48,10 +49,15 @@ func main() {
 	alertEventModel := models.NewAlertEventModel(pool)
 	notifConfigModel := models.NewNotificationConfigModel(pool)
 
+	emailDigestSvc := services.NewEmailDigestService(
+		cfg.ResendAPIKey, cfg.EmailFrom, alertEventModel, notifConfigModel,
+	)
+
 	addressHandler := handlers.NewAddressHandler(addressModel)
 	alertRuleHandler := handlers.NewAlertRuleHandler(alertRuleModel, addressModel)
 	alertEventHandler := handlers.NewAlertEventHandler(alertEventModel)
-	notifConfigHandler := handlers.NewNotificationConfigHandler(notifConfigModel)
+	notifConfigHandler := handlers.NewNotificationConfigHandler(notifConfigModel, cfg)
+	emailDigestHandler := handlers.NewEmailDigestHandler(emailDigestSvc, notifConfigModel)
 
 	mux := http.NewServeMux()
 	b := cfg.APIBasePath // e.g. "/v1"
@@ -89,6 +95,14 @@ func main() {
 		middleware.Authenticate(http.HandlerFunc(notifConfigHandler.UpdateConfig)))
 	mux.Handle("DELETE "+b+"/notification-config",
 		middleware.Authenticate(http.HandlerFunc(notifConfigHandler.DeleteConfig)))
+	mux.Handle("POST "+b+"/notification-config/test",
+		middleware.Authenticate(http.HandlerFunc(notifConfigHandler.TestChannels)))
+
+	// Authenticated routes — email digest
+	mux.Handle("POST "+b+"/email/setup",
+		middleware.Authenticate(http.HandlerFunc(emailDigestHandler.SetupEmail)))
+	mux.Handle("POST "+b+"/email/digest",
+		middleware.Authenticate(http.HandlerFunc(emailDigestHandler.SendDigest)))
 
 	handler := corsMiddleware(mux)
 

backend-go/cmd/poller/main.go

@@ -58,7 +58,10 @@ func main() {
 	notifConfigModel := models.NewNotificationConfigModel(pool)
 
 	observer := services.NewObserverService(eth, addressModel, checkpointModel)
-	evaluator := services.NewEvaluatorService(eth, alertRuleModel, alertEventModel, addressModel, notifConfigModel)
+	evaluator := services.NewEvaluatorService(
+		eth, alertRuleModel, alertEventModel, addressModel, notifConfigModel,
+		cfg.ResendAPIKey, cfg.EmailFrom,
+	)
 
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()

backend-go/infra/migrations/003_add_slack_webhook.sql

@@ -0,0 +1,2 @@
+ALTER TABLE user_notification_configs
+  ADD COLUMN IF NOT EXISTS slack_webhook_url TEXT;

backend-go/infra/schema.sql

@@ -54,8 +54,9 @@ CREATE TABLE user_notification_configs (
   user_id VARCHAR(128) PRIMARY KEY,
   discord_webhook_url TEXT,            -- Discord webhook URL (nullable)
   telegram_chat_id VARCHAR(128),       -- Telegram chat ID (nullable)
-  telegram_bot_token VARCHAR(255),     -- Telegram bot token (nullable, future use)
+  telegram_bot_token VARCHAR(255),     -- Telegram bot token (nullable)
   email VARCHAR(255),                  -- Email for notifications (nullable)
+  slack_webhook_url TEXT,              -- Slack incoming webhook URL (nullable)
   notification_enabled BOOLEAN DEFAULT TRUE,  -- Master on/off switch
   created_at TIMESTAMP DEFAULT NOW(),
   updated_at TIMESTAMP DEFAULT NOW()

backend-go/internal/config/config.go

@@ -28,6 +28,8 @@ type Config struct {
 	EthRPCURL         string
 	PollIntervalMS    int
 	NodeEnv           string
+	ResendAPIKey      string
+	EmailFrom         string
 }
 
 // Load reads configuration from environment variables and returns a Config.
@@ -45,6 +47,8 @@ func Load() (*Config, error) {
 		EthRPCURL:         os.Getenv("ETH_RPC_URL"),
 		PollIntervalMS:    getEnvInt("POLL_INTERVAL_MS", defaultPollIntervalMS),
 		NodeEnv:           getEnv("NODE_ENV", "development"),
+		ResendAPIKey:      os.Getenv("RESEND_API_KEY"),
+		EmailFrom:         getEnv("EMAIL_FROM", "Koin Ping <alerts@koinping.com>"),
 	}
 
 	if cfg.PollIntervalMS < minPollIntervalMS {

backend-go/internal/domain/types.go

@@ -103,8 +103,9 @@ type NotificationConfig struct {
 	UserID              string     `json:"user_id"`              //nolint:tagliatelle
 	DiscordWebhookURL   *string    `json:"discord_webhook_url"`  //nolint:tagliatelle
 	TelegramChatID      *string    `json:"telegram_chat_id"`     //nolint:tagliatelle
-	TelegramBotToken    *string    `json:"telegram_bot_token,omitempty"` //nolint:tagliatelle
+	TelegramBotToken    *string    `json:"telegram_bot_token"`   //nolint:tagliatelle
 	Email               *string    `json:"email"`
+	SlackWebhookURL     *string    `json:"slack_webhook_url"`    //nolint:tagliatelle
 	NotificationEnabled bool       `json:"notification_enabled"` //nolint:tagliatelle
 	CreatedAt           *time.Time `json:"created_at,omitempty"` //nolint:tagliatelle
 	UpdatedAt           *time.Time `json:"updated_at,omitempty"` //nolint:tagliatelle

backend-go/internal/handlers/email_digest.go

@@ -0,0 +1,101 @@
+package handlers
+
+import (
+	"log"
+	"net/http"
+
+	"github.com/kjannette/koin-ping/backend-go/internal/middleware"
+	"github.com/kjannette/koin-ping/backend-go/internal/models"
+	"github.com/kjannette/koin-ping/backend-go/internal/services"
+)
+
+type EmailDigestHandler struct {
+	digestSvc *services.EmailDigestService
+	configs   *models.NotificationConfigModel
+}
+
+func NewEmailDigestHandler(
+	digestSvc *services.EmailDigestService,
+	configs *models.NotificationConfigModel,
+) *EmailDigestHandler {
+	return &EmailDigestHandler{digestSvc: digestSvc, configs: configs}
+}
+
+// SetupEmail reads the user's email from their notification config and sends
+// a confirmation message via Resend to verify the integration works.
+func (h *EmailDigestHandler) SetupEmail(w http.ResponseWriter, r *http.Request) {
+	userID := middleware.GetUserID(r.Context())
+
+	if !h.digestSvc.Configured() {
+		writeError(w, http.StatusServiceUnavailable, "EMAIL_NOT_CONFIGURED",
+			"Email service is not configured on the server")
+		return
+	}
+
+	cfg, err := h.configs.GetConfig(r.Context(), userID)
+	if err != nil {
+		log.Printf("Error getting notification config for email setup: %v", err)
+		writeError(w, http.StatusInternalServerError, "INTERNAL_ERROR",
+			"Failed to load notification config")
+		return
+	}
+
+	if cfg == nil || cfg.Email == nil || *cfg.Email == "" {
+		writeError(w, http.StatusBadRequest, "VALIDATION_ERROR",
+			"Save an email address in notification settings first")
+		return
+	}
+
+	if err := h.digestSvc.SetupEmail(*cfg.Email); err != nil {
+		log.Printf("Email setup failed for user %s: %v", userID, err)
+		writeError(w, http.StatusBadGateway, "EMAIL_SEND_FAILED",
+			"Failed to send confirmation email — check server email config")
+		return
+	}
+
+	log.Printf("Email setup confirmation sent to user %s (%s)", userID, *cfg.Email)
+	writeJSON(w, http.StatusOK, map[string]any{
+		"success": true,
+		"email":   *cfg.Email,
+		"message": "Confirmation email sent",
+	})
+}
+
+// SendDigest compiles and sends a digest of recent alerts to the user's email.
+func (h *EmailDigestHandler) SendDigest(w http.ResponseWriter, r *http.Request) {
+	userID := middleware.GetUserID(r.Context())
+
+	if !h.digestSvc.Configured() {
+		writeError(w, http.StatusServiceUnavailable, "EMAIL_NOT_CONFIGURED",
+			"Email service is not configured on the server")
+		return
+	}
+
+	cfg, err := h.configs.GetConfig(r.Context(), userID)
+	if err != nil {
+		log.Printf("Error getting notification config for digest: %v", err)
+		writeError(w, http.StatusInternalServerError, "INTERNAL_ERROR",
+			"Failed to load notification config")
+		return
+	}
+
+	if cfg == nil || cfg.Email == nil || *cfg.Email == "" {
+		writeError(w, http.StatusBadRequest, "VALIDATION_ERROR",
+			"No email address configured")
+		return
+	}
+
+	if err := h.digestSvc.SendDigest(r.Context(), userID, *cfg.Email); err != nil {
+		log.Printf("Digest send failed for user %s: %v", userID, err)
+		writeError(w, http.StatusBadGateway, "DIGEST_SEND_FAILED",
+			"Failed to send digest email")
+		return
+	}
+
+	log.Printf("Digest sent to user %s (%s)", userID, *cfg.Email)
+	writeJSON(w, http.StatusOK, map[string]any{
+		"success": true,
+		"email":   *cfg.Email,
+		"message": "Digest email sent",
+	})
+}

backend-go/internal/handlers/notification_config.go

@@ -7,19 +7,22 @@ import (
 	"regexp"
 	"strings"
 
+	"github.com/kjannette/koin-ping/backend-go/internal/config"
 	"github.com/kjannette/koin-ping/backend-go/internal/domain"
 	"github.com/kjannette/koin-ping/backend-go/internal/middleware"
 	"github.com/kjannette/koin-ping/backend-go/internal/models"
+	"github.com/kjannette/koin-ping/backend-go/internal/notifications"
 )
 
 var emailRe = regexp.MustCompile(`^[^\s@]+@[^\s@]+\.[^\s@]+$`)
 
 type NotificationConfigHandler struct {
 	configs *models.NotificationConfigModel
+	cfg     *config.Config
 }
 
-func NewNotificationConfigHandler(configs *models.NotificationConfigModel) *NotificationConfigHandler {
+func NewNotificationConfigHandler(configs *models.NotificationConfigModel, cfg *config.Config) *NotificationConfigHandler {
-	return &NotificationConfigHandler{configs: configs}
+	return &NotificationConfigHandler{configs: configs, cfg: cfg}
 }
 
 func (h *NotificationConfigHandler) GetConfig(w http.ResponseWriter, r *http.Request) {
@@ -51,7 +54,9 @@ func (h *NotificationConfigHandler) UpdateConfig(w http.ResponseWriter, r *http.
 	var body struct {
 		DiscordWebhookURL   *string `json:"discord_webhook_url"`
 		TelegramChatID      *string `json:"telegram_chat_id"`
+		TelegramBotToken    *string `json:"telegram_bot_token"`
 		Email               *string `json:"email"`
+		SlackWebhookURL     *string `json:"slack_webhook_url"`
 		NotificationEnabled *bool   `json:"notification_enabled"`
 	}
 	if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
@@ -63,7 +68,8 @@ func (h *NotificationConfigHandler) UpdateConfig(w http.ResponseWriter, r *http.
 	log.Printf("User %s updating notification config", userID)
 
 	if body.DiscordWebhookURL == nil && body.TelegramChatID == nil &&
-		body.Email == nil && body.NotificationEnabled == nil {
+		body.TelegramBotToken == nil && body.Email == nil &&
+		body.SlackWebhookURL == nil && body.NotificationEnabled == nil {
 		writeError(w, http.StatusBadRequest, "VALIDATION_ERROR",
 			"At least one configuration field must be provided")
 		return
@@ -76,6 +82,13 @@ func (h *NotificationConfigHandler) UpdateConfig(w http.ResponseWriter, r *http.
 		return
 	}
 
+	if body.SlackWebhookURL != nil && *body.SlackWebhookURL != "" &&
+		!strings.HasPrefix(*body.SlackWebhookURL, "https://hooks.slack.com/") {
+		writeError(w, http.StatusBadRequest, "VALIDATION_ERROR",
+			"Invalid Slack webhook URL format")
+		return
+	}
+
 	if body.Email != nil && *body.Email != "" && !emailRe.MatchString(*body.Email) {
 		writeError(w, http.StatusBadRequest, "VALIDATION_ERROR",
 			"Invalid email address format")
@@ -90,7 +103,9 @@ func (h *NotificationConfigHandler) UpdateConfig(w http.ResponseWriter, r *http.
 	cfg := domain.NotificationConfig{
 		DiscordWebhookURL:   body.DiscordWebhookURL,
 		TelegramChatID:      body.TelegramChatID,
+		TelegramBotToken:    body.TelegramBotToken,
 		Email:               body.Email,
+		SlackWebhookURL:     body.SlackWebhookURL,
 		NotificationEnabled: enabled,
 	}
 
@@ -126,3 +141,76 @@ func (h *NotificationConfigHandler) DeleteConfig(w http.ResponseWriter, r *http.
 	log.Println("Notification config deleted")
 	w.WriteHeader(http.StatusNoContent)
 }
+
+// TestChannels sends a test message to all configured notification channels.
+func (h *NotificationConfigHandler) TestChannels(w http.ResponseWriter, r *http.Request) {
+	userID := middleware.GetUserID(r.Context())
+	log.Printf("User %s testing notification channels", userID)
+
+	cfg, err := h.configs.GetConfig(r.Context(), userID)
+	if err != nil {
+		log.Printf("Error getting notification config for test: %v", err)
+		writeError(w, http.StatusInternalServerError, "INTERNAL_ERROR", "Failed to get notification config")
+		return
+	}
+
+	if cfg == nil {
+		writeError(w, http.StatusNotFound, "NOT_FOUND", "No notification configuration found")
+		return
+	}
+
+	type channelResult struct {
+		Channel string `json:"channel"`
+		Success bool   `json:"success"`
+		Error   string `json:"error,omitempty"`
+	}
+
+	var results []channelResult
+
+	if cfg.DiscordWebhookURL != nil && *cfg.DiscordWebhookURL != "" {
+		ok, testErr := notifications.TestDiscordWebhook(*cfg.DiscordWebhookURL)
+		res := channelResult{Channel: "discord", Success: ok}
+		if testErr != nil {
+			res.Error = testErr.Error()
+		}
+		results = append(results, res)
+	}
+
+	if cfg.TelegramBotToken != nil && *cfg.TelegramBotToken != "" &&
+		cfg.TelegramChatID != nil && *cfg.TelegramChatID != "" {
+		ok, testErr := notifications.TestTelegramWebhook(*cfg.TelegramBotToken, *cfg.TelegramChatID)
+		res := channelResult{Channel: "telegram", Success: ok}
+		if testErr != nil {
+			res.Error = testErr.Error()
+		}
+		results = append(results, res)
+	}
+
+	if cfg.SlackWebhookURL != nil && *cfg.SlackWebhookURL != "" {
+		ok, testErr := notifications.TestSlackWebhook(*cfg.SlackWebhookURL)
+		res := channelResult{Channel: "slack", Success: ok}
+		if testErr != nil {
+			res.Error = testErr.Error()
+		}
+		results = append(results, res)
+	}
+
+	if cfg.Email != nil && *cfg.Email != "" {
+		ok, testErr := notifications.TestEmailNotification(
+			h.cfg.ResendAPIKey, h.cfg.EmailFrom, *cfg.Email,
+		)
+		res := channelResult{Channel: "email", Success: ok}
+		if testErr != nil {
+			res.Error = testErr.Error()
+		}
+		results = append(results, res)
+	}
+
+	if len(results) == 0 {
+		writeError(w, http.StatusBadRequest, "NO_CHANNELS",
+			"No notification channels are configured")
+		return
+	}
+
+	writeJSON(w, http.StatusOK, map[string]any{"results": results})
+}

backend-go/internal/models/notification_config.go

@@ -21,12 +21,12 @@ func (m *NotificationConfigModel) GetConfig(ctx context.Context, userID string)
 	var c domain.NotificationConfig
 	err := m.pool.QueryRow(ctx,
 		`SELECT user_id, discord_webhook_url, telegram_chat_id, telegram_bot_token,
-		        email, notification_enabled, created_at, updated_at
+		        email, slack_webhook_url, notification_enabled, created_at, updated_at
 		 FROM user_notification_configs
 		 WHERE user_id = $1`,
 		userID,
 	).Scan(&c.UserID, &c.DiscordWebhookURL, &c.TelegramChatID, &c.TelegramBotToken,
-		&c.Email, &c.NotificationEnabled, &c.CreatedAt, &c.UpdatedAt)
+		&c.Email, &c.SlackWebhookURL, &c.NotificationEnabled, &c.CreatedAt, &c.UpdatedAt)
 	if err != nil {
 		if errors.Is(err, pgx.ErrNoRows) {
 			return nil, nil
@@ -40,22 +40,24 @@ func (m *NotificationConfigModel) UpsertConfig(ctx context.Context, userID strin
 	var c domain.NotificationConfig
 	err := m.pool.QueryRow(ctx,
 		`INSERT INTO user_notification_configs
-		   (user_id, discord_webhook_url, telegram_chat_id, telegram_bot_token, email, notification_enabled, updated_at)
+		   (user_id, discord_webhook_url, telegram_chat_id, telegram_bot_token,
-		 VALUES ($1, $2, $3, $4, $5, $6, NOW())
+		    email, slack_webhook_url, notification_enabled, updated_at)
+		 VALUES ($1, $2, $3, $4, $5, $6, $7, NOW())
 		 ON CONFLICT (user_id)
 		 DO UPDATE SET
 		   discord_webhook_url = COALESCE($2, user_notification_configs.discord_webhook_url),
 		   telegram_chat_id = COALESCE($3, user_notification_configs.telegram_chat_id),
 		   telegram_bot_token = COALESCE($4, user_notification_configs.telegram_bot_token),
 		   email = COALESCE($5, user_notification_configs.email),
-		   notification_enabled = $6,
+		   slack_webhook_url = COALESCE($6, user_notification_configs.slack_webhook_url),
+		   notification_enabled = $7,
 		   updated_at = NOW()
 		 RETURNING user_id, discord_webhook_url, telegram_chat_id, telegram_bot_token,
-		           email, notification_enabled, created_at, updated_at`,
+		           email, slack_webhook_url, notification_enabled, created_at, updated_at`,
 		userID, cfg.DiscordWebhookURL, cfg.TelegramChatID, cfg.TelegramBotToken,
-		cfg.Email, cfg.NotificationEnabled,
+		cfg.Email, cfg.SlackWebhookURL, cfg.NotificationEnabled,
 	).Scan(&c.UserID, &c.DiscordWebhookURL, &c.TelegramChatID, &c.TelegramBotToken,
-		&c.Email, &c.NotificationEnabled, &c.CreatedAt, &c.UpdatedAt)
+		&c.Email, &c.SlackWebhookURL, &c.NotificationEnabled, &c.CreatedAt, &c.UpdatedAt)
 	if err != nil {
 		return nil, err
 	}
@@ -75,7 +77,8 @@ func (m *NotificationConfigModel) Remove(ctx context.Context, userID string) (bo
 
 func (m *NotificationConfigModel) ListEnabled(ctx context.Context) ([]domain.NotificationConfig, error) {
 	rows, err := m.pool.Query(ctx,
-		`SELECT user_id, discord_webhook_url, telegram_chat_id, email
+		`SELECT user_id, discord_webhook_url, telegram_chat_id, telegram_bot_token,
+		        email, slack_webhook_url
 		 FROM user_notification_configs
 		 WHERE notification_enabled = TRUE`,
 	)
@@ -87,7 +90,8 @@ func (m *NotificationConfigModel) ListEnabled(ctx context.Context) ([]domain.Not
 	var configs []domain.NotificationConfig
 	for rows.Next() {
 		var c domain.NotificationConfig
-		if err := rows.Scan(&c.UserID, &c.DiscordWebhookURL, &c.TelegramChatID, &c.Email); err != nil {
+		if err := rows.Scan(&c.UserID, &c.DiscordWebhookURL, &c.TelegramChatID,
+			&c.TelegramBotToken, &c.Email, &c.SlackWebhookURL); err != nil {
 			return nil, err
 		}
 		c.NotificationEnabled = true

backend-go/internal/notifications/email.go

@@ -0,0 +1,142 @@
+package notifications
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"log"
+	"net/http"
+	"time"
+)
+
+const emailHTTPTimeoutSeconds = 10
+
+var emailHTTPClient = &http.Client{ //nolint:gochecknoglobals
+	Timeout: emailHTTPTimeoutSeconds * time.Second,
+}
+
+type resendPayload struct {
+	From    string `json:"from"`
+	To      string `json:"to"`
+	Subject string `json:"subject"`
+	HTML    string `json:"html"`
+}
+
+func SendEmailNotification(apiKey, fromAddress, toAddress, message string, meta AlertMetadata) (bool, error) {
+	if apiKey == "" {
+		log.Printf("Skipping email notification: RESEND_API_KEY not configured")
+		return false, nil
+	}
+
+	subject := fmt.Sprintf("Koin Ping Alert: %s", alertTypeLabel(meta.AlertType))
+
+	txLink := ""
+	if meta.TxHash != "" {
+		txLink = fmt.Sprintf(
+			`<p><a href="https://etherscan.io/tx/%s">View on Etherscan</a></p>`,
+			meta.TxHash,
+		)
+	}
+
+	html := fmt.Sprintf(`
+<div style="font-family: sans-serif; max-width: 600px; margin: 0 auto;">
+  <h2 style="color: #333;">Koin Ping Alert</h2>
+  <p style="font-size: 16px;">%s</p>
+  <table style="margin: 16px 0; border-collapse: collapse;">
+    <tr>
+      <td style="padding: 4px 12px 4px 0; color: #666;">Address</td>
+      <td style="padding: 4px 0;">%s</td>
+    </tr>
+    <tr>
+      <td style="padding: 4px 12px 4px 0; color: #666;">Blockchain</td>
+      <td style="padding: 4px 0; font-family: monospace; font-size: 13px;">%s</td>
+    </tr>
+  </table>
+  %s
+  <hr style="border: none; border-top: 1px solid #eee; margin: 24px 0;" />
+  <p style="font-size: 12px; color: #999;">Sent by Koin Ping</p>
+</div>`,
+		message, meta.AddressLabel, meta.Address, txLink)
+
+	payload := resendPayload{
+		From:    fromAddress,
+		To:      toAddress,
+		Subject: subject,
+		HTML:    html,
+	}
+
+	body, err := json.Marshal(payload)
+	if err != nil {
+		return false, fmt.Errorf("marshal email payload: %w", err)
+	}
+
+	req, err := http.NewRequest(http.MethodPost, "https://api.resend.com/emails", bytes.NewReader(body))
+	if err != nil {
+		return false, fmt.Errorf("create email request: %w", err)
+	}
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("Authorization", "Bearer "+apiKey)
+
+	resp, err := emailHTTPClient.Do(req)
+	if err != nil {
+		log.Printf("Failed to send email notification: %v", err)
+		return false, err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
+		log.Printf("Resend API failed: HTTP %d", resp.StatusCode)
+		return false, fmt.Errorf("resend API failed: HTTP %d", resp.StatusCode)
+	}
+
+	return true, nil
+}
+
+func TestEmailNotification(apiKey, fromAddress, toAddress string) (bool, error) {
+	if apiKey == "" {
+		return false, fmt.Errorf("email not configured: RESEND_API_KEY not set") //nolint:err113
+	}
+
+	payload := resendPayload{
+		From:    fromAddress,
+		To:      toAddress,
+		Subject: "Koin Ping — Test Notification",
+		HTML:    `<p>Your email alerts are configured correctly!</p><p style="font-size:12px;color:#999;">Sent by Koin Ping</p>`,
+	}
+
+	body, err := json.Marshal(payload)
+	if err != nil {
+		return false, err
+	}
+
+	req, err := http.NewRequest(http.MethodPost, "https://api.resend.com/emails", bytes.NewReader(body))
+	if err != nil {
+		return false, err
+	}
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("Authorization", "Bearer "+apiKey)
+
+	resp, err := emailHTTPClient.Do(req)
+	if err != nil {
+		log.Printf("Email test failed: %v", err)
+		return false, err
+	}
+	defer resp.Body.Close()
+
+	return resp.StatusCode >= 200 && resp.StatusCode < 300, nil
+}
+
+func alertTypeLabel(alertType string) string {
+	switch alertType {
+	case "incoming_tx":
+		return "Incoming Transaction"
+	case "outgoing_tx":
+		return "Outgoing Transaction"
+	case "large_transfer":
+		return "Large Transfer"
+	case "balance_below":
+		return "Balance Below Threshold"
+	default:
+		return "Alert"
+	}
+}

backend-go/internal/notifications/slack.go

@@ -0,0 +1,116 @@
+package notifications
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"log"
+	"net/http"
+	"time"
+)
+
+const slackHTTPTimeoutSeconds = 10
+
+var slackHTTPClient = &http.Client{ //nolint:gochecknoglobals
+	Timeout: slackHTTPTimeoutSeconds * time.Second,
+}
+
+type slackAttachment struct {
+	Color  string        `json:"color"`
+	Title  string        `json:"title"`
+	Text   string        `json:"text"`
+	Fields []slackField  `json:"fields"`
+	Footer string        `json:"footer"`
+	Ts     int64         `json:"ts"`
+}
+
+type slackField struct {
+	Title string `json:"title"`
+	Value string `json:"value"`
+	Short bool   `json:"short"`
+}
+
+type slackPayload struct {
+	Text        string            `json:"text,omitempty"`
+	Attachments []slackAttachment `json:"attachments,omitempty"`
+}
+
+func SendSlackNotification(webhookURL, message string, meta AlertMetadata) (bool, error) {
+	fields := []slackField{
+		{Title: "Address", Value: meta.AddressLabel, Short: true},
+		{Title: "Blockchain Address", Value: fmt.Sprintf("`%s`", meta.Address), Short: false},
+	}
+
+	if meta.TxHash != "" {
+		fields = append(fields, slackField{
+			Title: "Transaction",
+			Value: fmt.Sprintf("<https://etherscan.io/tx/%s|View on Etherscan>", meta.TxHash),
+			Short: false,
+		})
+	}
+
+	payload := slackPayload{
+		Attachments: []slackAttachment{
+			{
+				Color:  slackColorForAlertType(meta.AlertType),
+				Title:  "Koin Ping Alert",
+				Text:   message,
+				Fields: fields,
+				Footer: "Koin Ping",
+				Ts:     time.Now().Unix(),
+			},
+		},
+	}
+
+	body, err := json.Marshal(payload)
+	if err != nil {
+		return false, fmt.Errorf("marshal slack payload: %w", err)
+	}
+
+	resp, err := slackHTTPClient.Post(webhookURL, "application/json", bytes.NewReader(body))
+	if err != nil {
+		log.Printf("Failed to send Slack notification: %v", err)
+		return false, err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
+		log.Printf("Slack webhook failed: HTTP %d", resp.StatusCode)
+		return false, fmt.Errorf("slack webhook failed: HTTP %d", resp.StatusCode)
+	}
+
+	return true, nil
+}
+
+func TestSlackWebhook(webhookURL string) (bool, error) {
+	payload := slackPayload{
+		Text: "Koin Ping test notification — Your Slack alerts are configured correctly!",
+	}
+
+	body, err := json.Marshal(payload)
+	if err != nil {
+		return false, err
+	}
+
+	resp, err := slackHTTPClient.Post(webhookURL, "application/json", bytes.NewReader(body))
+	if err != nil {
+		log.Printf("Slack webhook test failed: %v", err)
+		return false, err
+	}
+	defer resp.Body.Close()
+
+	return resp.StatusCode >= 200 && resp.StatusCode < 300, nil
+}
+
+func slackColorForAlertType(alertType string) string {
+	switch alertType {
+	case "incoming_tx":
+		return "#00ff00"
+	case "outgoing_tx":
+		return "#ff9900"
+	case "large_transfer", "balance_below":
+		return "#ff0000"
+	default:
+		return "#0099ff"
+	}
+}

backend-go/internal/notifications/telegram.go

@@ -0,0 +1,109 @@
+package notifications
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"log"
+	"net/http"
+	"time"
+)
+
+const telegramHTTPTimeoutSeconds = 10
+
+var telegramHTTPClient = &http.Client{ //nolint:gochecknoglobals
+	Timeout: telegramHTTPTimeoutSeconds * time.Second,
+}
+
+type telegramPayload struct {
+	ChatID    string `json:"chat_id"`
+	Text      string `json:"text"`
+	ParseMode string `json:"parse_mode"`
+}
+
+func SendTelegramNotification(botToken, chatID, message string, meta AlertMetadata) (bool, error) {
+	text := fmt.Sprintf("*Koin Ping Alert*\n\n%s\n\n*Address:* %s\n`%s`",
+		escapeMarkdown(message), escapeMarkdown(meta.AddressLabel), meta.Address)
+
+	if meta.TxHash != "" {
+		text += fmt.Sprintf("\n\n[View on Etherscan](https://etherscan.io/tx/%s)", meta.TxHash)
+	}
+
+	payload := telegramPayload{
+		ChatID:    chatID,
+		Text:      text,
+		ParseMode: "Markdown",
+	}
+
+	body, err := json.Marshal(payload)
+	if err != nil {
+		return false, fmt.Errorf("marshal telegram payload: %w", err)
+	}
+
+	url := fmt.Sprintf("https://api.telegram.org/bot%s/sendMessage", botToken)
+
+	resp, err := telegramHTTPClient.Post(url, "application/json", bytes.NewReader(body))
+	if err != nil {
+		log.Printf("Failed to send Telegram notification: %v", err)
+		return false, err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
+		log.Printf("Telegram API failed: HTTP %d", resp.StatusCode)
+		return false, fmt.Errorf("telegram API failed: HTTP %d", resp.StatusCode)
+	}
+
+	return true, nil
+}
+
+func TestTelegramWebhook(botToken, chatID string) (bool, error) {
+	payload := telegramPayload{
+		ChatID:    chatID,
+		Text:      "Koin Ping test notification — Your Telegram alerts are configured correctly!",
+		ParseMode: "Markdown",
+	}
+
+	body, err := json.Marshal(payload)
+	if err != nil {
+		return false, err
+	}
+
+	url := fmt.Sprintf("https://api.telegram.org/bot%s/sendMessage", botToken)
+
+	resp, err := telegramHTTPClient.Post(url, "application/json", bytes.NewReader(body))
+	if err != nil {
+		log.Printf("Telegram test failed: %v", err)
+		return false, err
+	}
+	defer resp.Body.Close()
+
+	return resp.StatusCode >= 200 && resp.StatusCode < 300, nil
+}
+
+func escapeMarkdown(s string) string {
+	replacer := []struct{ old, new string }{
+		{"_", "\\_"}, {"*", "\\*"}, {"[", "\\["}, {"]", "\\]"},
+		{"(", "\\("}, {")", "\\)"}, {"~", "\\~"}, {"`", "\\`"},
+		{">", "\\>"}, {"#", "\\#"}, {"+", "\\+"}, {"-", "\\-"},
+		{"=", "\\="}, {"|", "\\|"}, {"{", "\\{"}, {"}", "\\}"},
+		{".", "\\."}, {"!", "\\!"},
+	}
+	result := s
+	for _, r := range replacer {
+		result = replaceAll(result, r.old, r.new)
+	}
+	return result
+}
+
+func replaceAll(s, old, new string) string {
+	out := ""
+	for i := 0; i < len(s); i++ {
+		if string(s[i]) == old {
+			out += new
+		} else {
+			out += string(s[i])
+		}
+	}
+	return out
+}

backend-go/internal/services/email_digest.go

@@ -0,0 +1,199 @@
+package services
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"log"
+	"net/http"
+	"time"
+
+	"github.com/kjannette/koin-ping/backend-go/internal/models"
+)
+
+const (
+	resendAPIURL          = "https://api.resend.com/emails"
+	emailHTTPTimeout      = 10 * time.Second
+	defaultDigestMaxItems = 50
+)
+
+var digestHTTPClient = &http.Client{Timeout: emailHTTPTimeout} //nolint:gochecknoglobals
+
+// EmailDigestService handles email setup and digest sending via Resend.
+type EmailDigestService struct {
+	apiKey      string
+	fromAddress string
+	alertEvents *models.AlertEventModel
+	notifCfgs   *models.NotificationConfigModel
+}
+
+func NewEmailDigestService(
+	apiKey, fromAddress string,
+	alertEvents *models.AlertEventModel,
+	notifCfgs *models.NotificationConfigModel,
+) *EmailDigestService {
+	return &EmailDigestService{
+		apiKey:      apiKey,
+		fromAddress: fromAddress,
+		alertEvents: alertEvents,
+		notifCfgs:   notifCfgs,
+	}
+}
+
+// Configured returns true when the Resend API key is present.
+func (s *EmailDigestService) Configured() bool {
+	return s.apiKey != ""
+}
+
+// SetupEmail validates the email works by sending a welcome/confirmation
+// message via Resend. Called when a user saves their email in notification settings.
+func (s *EmailDigestService) SetupEmail(toAddress string) error {
+	if !s.Configured() {
+		return fmt.Errorf("email service not configured: RESEND_API_KEY not set") //nolint:err113
+	}
+
+	html := `
+<div style="font-family: sans-serif; max-width: 600px; margin: 0 auto;">
+  <h2 style="color: #333;">Welcome to Koin Ping Email Alerts</h2>
+  <p>Your email has been successfully configured for alert notifications.</p>
+  <p>You will receive alert digests at this address when events are triggered
+     on your watched addresses.</p>
+  <hr style="border: none; border-top: 1px solid #eee; margin: 24px 0;" />
+  <p style="font-size: 12px; color: #999;">Sent by Koin Ping</p>
+</div>`
+
+	return s.send(toAddress, "Koin Ping — Email Alerts Configured", html)
+}
+
+// SendDigest compiles recent alert events for a user and sends a digest email.
+func (s *EmailDigestService) SendDigest(ctx context.Context, userID, toAddress string) error {
+	if !s.Configured() {
+		return fmt.Errorf("email service not configured: RESEND_API_KEY not set") //nolint:err113
+	}
+
+	events, err := s.alertEvents.ListRecentByUser(ctx, userID, defaultDigestMaxItems)
+	if err != nil {
+		return fmt.Errorf("fetch alert events: %w", err)
+	}
+
+	if len(events) == 0 {
+		log.Printf("No recent alerts for user %s — skipping digest", userID)
+		return nil
+	}
+
+	var rows string
+	for _, e := range events {
+		label := "—"
+		if e.AddressLabel != nil {
+			label = *e.AddressLabel
+		}
+		txLink := "—"
+		if e.TxHash != nil {
+			txLink = fmt.Sprintf(
+				`<a href="https://etherscan.io/tx/%s" style="color:#0066cc;">%s…</a>`,
+				*e.TxHash, (*e.TxHash)[:10],
+			)
+		}
+		rows += fmt.Sprintf(`
+      <tr>
+        <td style="padding:6px 8px; border-bottom:1px solid #eee;">%s</td>
+        <td style="padding:6px 8px; border-bottom:1px solid #eee;">%s</td>
+        <td style="padding:6px 8px; border-bottom:1px solid #eee;">%s</td>
+        <td style="padding:6px 8px; border-bottom:1px solid #eee; font-size:12px; color:#666;">%s</td>
+      </tr>`,
+			label, e.Message, txLink,
+			e.Timestamp.Format("Jan 2 15:04 UTC"),
+		)
+	}
+
+	html := fmt.Sprintf(`
+<div style="font-family: sans-serif; max-width: 700px; margin: 0 auto;">
+  <h2 style="color: #333;">Koin Ping — Alert Digest</h2>
+  <p>Here are your recent alerts (%d total):</p>
+  <table style="width:100%%; border-collapse:collapse; font-size:14px;">
+    <thead>
+      <tr style="background:#f5f5f5;">
+        <th style="padding:8px; text-align:left;">Address</th>
+        <th style="padding:8px; text-align:left;">Alert</th>
+        <th style="padding:8px; text-align:left;">Tx</th>
+        <th style="padding:8px; text-align:left;">Time</th>
+      </tr>
+    </thead>
+    <tbody>%s</tbody>
+  </table>
+  <hr style="border:none; border-top:1px solid #eee; margin:24px 0;" />
+  <p style="font-size:12px; color:#999;">Sent by Koin Ping</p>
+</div>`, len(events), rows)
+
+	subject := fmt.Sprintf("Koin Ping Digest — %d alerts", len(events))
+
+	return s.send(toAddress, subject, html)
+}
+
+// SendDigestsForAllUsers sends a digest email to every user that has
+// notifications enabled and an email configured.
+func (s *EmailDigestService) SendDigestsForAllUsers(ctx context.Context) (int, error) {
+	if !s.Configured() {
+		return 0, nil
+	}
+
+	configs, err := s.notifCfgs.ListEnabled(ctx)
+	if err != nil {
+		return 0, fmt.Errorf("list enabled configs: %w", err)
+	}
+
+	sent := 0
+	for _, cfg := range configs {
+		if cfg.Email == nil || *cfg.Email == "" {
+			continue
+		}
+		if err := s.SendDigest(ctx, cfg.UserID, *cfg.Email); err != nil {
+			log.Printf("Failed to send digest to user %s: %v", cfg.UserID, err)
+			continue
+		}
+		sent++
+	}
+
+	return sent, nil
+}
+
+type resendEmailPayload struct {
+	From    string `json:"from"`
+	To      string `json:"to"`
+	Subject string `json:"subject"`
+	HTML    string `json:"html"`
+}
+
+func (s *EmailDigestService) send(to, subject, html string) error {
+	payload := resendEmailPayload{
+		From:    s.fromAddress,
+		To:      to,
+		Subject: subject,
+		HTML:    html,
+	}
+
+	body, err := json.Marshal(payload)
+	if err != nil {
+		return fmt.Errorf("marshal email payload: %w", err)
+	}
+
+	req, err := http.NewRequest(http.MethodPost, resendAPIURL, bytes.NewReader(body))
+	if err != nil {
+		return fmt.Errorf("create request: %w", err)
+	}
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("Authorization", "Bearer "+s.apiKey)
+
+	resp, err := digestHTTPClient.Do(req)
+	if err != nil {
+		return fmt.Errorf("send email via Resend: %w", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
+		return fmt.Errorf("Resend API returned HTTP %d", resp.StatusCode) //nolint:err113
+	}
+
+	return nil
+}

backend-go/internal/services/evaluator.go

@@ -18,6 +18,8 @@ type EvaluatorService struct {
 	alertEvents  *models.AlertEventModel
 	addresses    *models.AddressModel
 	notifConfigs *models.NotificationConfigModel
+	resendAPIKey string
+	emailFrom    string
 }
 
 func NewEvaluatorService(
@@ -26,6 +28,8 @@ func NewEvaluatorService(
 	alertEvents *models.AlertEventModel,
 	addresses *models.AddressModel,
 	notifConfigs *models.NotificationConfigModel,
+	resendAPIKey string,
+	emailFrom string,
 ) *EvaluatorService {
 	return &EvaluatorService{
 		eth:          eth,
@@ -33,6 +37,8 @@ func NewEvaluatorService(
 		alertEvents:  alertEvents,
 		addresses:    addresses,
 		notifConfigs: notifConfigs,
+		resendAPIKey: resendAPIKey,
+		emailFrom:    emailFrom,
 	}
 }
 
@@ -187,28 +193,59 @@ func (s *EvaluatorService) sendNotification(ctx context.Context, userID, message
 		return
 	}
 
-	if notifConfig == nil || !notifConfig.NotificationEnabled || notifConfig.DiscordWebhookURL == nil {
+	if notifConfig == nil || !notifConfig.NotificationEnabled {
 		return
 	}
 
-	sent, err := notifications.SendDiscordNotification(
+	meta := notifications.AlertMetadata{
-		*notifConfig.DiscordWebhookURL,
-		message,
-		notifications.AlertMetadata{
 		TxHash:       obs.Hash,
 		AddressLabel: addressLabel,
 		AlertType:    string(rule.Type),
 		Address:      address,
-		},
+	}
-	)
 
-	if err != nil || !sent {
+	if notifConfig.DiscordWebhookURL != nil && *notifConfig.DiscordWebhookURL != "" {
-		log.Printf("Discord notification failed for user %s: %v", userID, err)
+		sent, sendErr := notifications.SendDiscordNotification(*notifConfig.DiscordWebhookURL, message, meta)
+		if sendErr != nil || !sent {
+			log.Printf("Discord notification failed for user %s: %v", userID, sendErr)
 		} else {
 			log.Printf("Discord notification sent to user %s", userID)
 		}
 	}
 
+	if notifConfig.TelegramBotToken != nil && *notifConfig.TelegramBotToken != "" &&
+		notifConfig.TelegramChatID != nil && *notifConfig.TelegramChatID != "" {
+		sent, sendErr := notifications.SendTelegramNotification(
+			*notifConfig.TelegramBotToken, *notifConfig.TelegramChatID, message, meta,
+		)
+		if sendErr != nil || !sent {
+			log.Printf("Telegram notification failed for user %s: %v", userID, sendErr)
+		} else {
+			log.Printf("Telegram notification sent to user %s", userID)
+		}
+	}
+
+	if notifConfig.SlackWebhookURL != nil && *notifConfig.SlackWebhookURL != "" {
+		sent, sendErr := notifications.SendSlackNotification(*notifConfig.SlackWebhookURL, message, meta)
+		if sendErr != nil || !sent {
+			log.Printf("Slack notification failed for user %s: %v", userID, sendErr)
+		} else {
+			log.Printf("Slack notification sent to user %s", userID)
+		}
+	}
+
+	if notifConfig.Email != nil && *notifConfig.Email != "" {
+		sent, sendErr := notifications.SendEmailNotification(
+			s.resendAPIKey, s.emailFrom, *notifConfig.Email, message, meta,
+		)
+		if sendErr != nil || !sent {
+			log.Printf("Email notification failed for user %s: %v", userID, sendErr)
+		} else {
+			log.Printf("Email notification sent to user %s", userID)
+		}
+	}
+}
+
 func (s *EvaluatorService) buildMessage(rule domain.AlertRule, obs domain.ObservedTx) string {
 	switch rule.Type {
 	case domain.AlertIncomingTx:

frontend/src/api/notificationConfig.jsx

@@ -1,5 +1,3 @@
-// API client for notification configuration
-
 import { getAuthHeaders } from "./authHeaders";
 import { API_BASE } from "./config";
 
@@ -38,11 +36,13 @@ export async function getNotificationConfig() {
 
 /**
  * Update notification configuration
- * @param {Object} config - Configuration to update
+ * @param {Object} config
- * @param {string} [config.discord_webhook_url] - Discord webhook URL
+ * @param {string} [config.discord_webhook_url]
- * @param {string} [config.telegram_chat_id] - Telegram chat ID
+ * @param {string} [config.telegram_chat_id]
- * @param {string} [config.email] - Email address
+ * @param {string} [config.telegram_bot_token]
- * @param {boolean} [config.notification_enabled] - Enable/disable notifications
+ * @param {string} [config.email]
+ * @param {string} [config.slack_webhook_url]
+ * @param {boolean} [config.notification_enabled]
  * @returns {Promise<Object>} Updated config
  */
 export async function updateNotificationConfig(config) {
@@ -77,27 +77,107 @@ export async function updateNotificationConfig(config) {
 }
 
 /**
- * Test a Discord webhook URL
+ * Set up email notifications via Resend.
- * Sends a test message to verify the webhook works
+ * Reads the user's saved email from their config and sends a confirmation.
- * @param {string} webhookUrl - Discord webhook URL to test
+ * @returns {Promise<Object>} Setup result
- * @returns {Promise<boolean>} True if test successful
  */
-export async function testDiscordWebhook(webhookUrl) {
+export async function setupEmail() {
     try {
-        const payload = {
+        const headers = await getAuthHeaders();
-            content:
+        const response = await fetch(`${API_BASE}/email/setup`, {
-                "Koin Ping test notification - Your Discord webhook is configured correctly!",
-        };
-
-        const response = await fetch(webhookUrl, {
             method: "POST",
-            headers: { "Content-Type": "application/json" },
+            headers: headers,
-            body: JSON.stringify(payload),
         });
 
-        return response.ok;
+        if (!response.ok) {
+            let errorMessage = "Failed to set up email";
+            try {
+                const error = await response.json();
+                errorMessage = error.message || errorMessage;
+            } catch {
+                errorMessage = `Server error: ${response.status} ${response.statusText}`;
+            }
+            throw new Error(errorMessage);
+        }
+
+        return response.json();
     } catch (error) {
-        console.error("Discord webhook test failed:", error);
+        if (error.message.includes("fetch")) {
-        return false;
+            throw new Error(
+                "Cannot connect to server. Is the backend running?",
+            );
+        }
+        throw error;
+    }
+}
+
+/**
+ * Send an alert digest email to the user's configured email address.
+ * @returns {Promise<Object>} Digest send result
+ */
+export async function sendEmailDigest() {
+    try {
+        const headers = await getAuthHeaders();
+        const response = await fetch(`${API_BASE}/email/digest`, {
+            method: "POST",
+            headers: headers,
+        });
+
+        if (!response.ok) {
+            let errorMessage = "Failed to send digest";
+            try {
+                const error = await response.json();
+                errorMessage = error.message || errorMessage;
+            } catch {
+                errorMessage = `Server error: ${response.status} ${response.statusText}`;
+            }
+            throw new Error(errorMessage);
+        }
+
+        return response.json();
+    } catch (error) {
+        if (error.message.includes("fetch")) {
+            throw new Error(
+                "Cannot connect to server. Is the backend running?",
+            );
+        }
+        throw error;
+    }
+}
+
+/**
+ * Test all configured notification channels via the backend
+ * @returns {Promise<Object>} Results per channel
+ */
+export async function testNotificationChannels() {
+    try {
+        const headers = await getAuthHeaders();
+        const response = await fetch(
+            `${API_BASE}/notification-config/test`,
+            {
+                method: "POST",
+                headers: headers,
+            },
+        );
+
+        if (!response.ok) {
+            let errorMessage = "Failed to test notification channels";
+            try {
+                const error = await response.json();
+                errorMessage = error.message || errorMessage;
+            } catch {
+                errorMessage = `Server error: ${response.status} ${response.statusText}`;
+            }
+            throw new Error(errorMessage);
+        }
+
+        return response.json();
+    } catch (error) {
+        if (error.message.includes("fetch")) {
+            throw new Error(
+                "Cannot connect to server. Is the backend running?",
+            );
+        }
+        throw error;
     }
 }

frontend/src/pages/Alerts.jsx

@@ -1,7 +1,6 @@
 import { useState, useEffect } from "react";
 import AlertForm from "../components/AlertForm";
 import Button from "../components/Button";
-import Input from "../components/Input";
 import { getAddresses } from "../api/addresses";
 import {
     getAlerts,
@@ -12,9 +11,40 @@ import {
 import {
     getNotificationConfig,
     updateNotificationConfig,
-    testDiscordWebhook,
+    testNotificationChannels,
+    setupEmail,
+    sendEmailDigest,
 } from "../api/notificationConfig";
 
+const inputStyle = {
+    width: "100%",
+    padding: "0.5rem",
+    fontSize: "0.9rem",
+    backgroundColor: "#1a1a1a",
+    border: "1px solid #444",
+    borderRadius: "4px",
+    color: "white",
+    fontFamily: "monospace",
+    boxSizing: "border-box",
+};
+
+const labelStyle = {
+    display: "block",
+    marginBottom: "0.25rem",
+    fontSize: "0.9rem",
+    color: "#ccc",
+};
+
+const helpLinkStyle = { color: "#0066cc", fontSize: "0.85rem" };
+
+const sectionStyle = {
+    marginBottom: "1.5rem",
+    padding: "1rem",
+    backgroundColor: "#2a2a2a",
+    borderRadius: "6px",
+    border: "1px solid #3a3a3a",
+};
+
 export default function Alerts() {
     const [addresses, setAddresses] = useState([]);
     const [selectedAddressId, setSelectedAddressId] = useState(null);
@@ -23,34 +53,39 @@ export default function Alerts() {
     const [error, setError] = useState(null);
 
     // Notification config state
-    const [notificationConfig, setNotificationConfig] = useState(null);
+    const [notificationEnabled, setNotificationEnabled] = useState(false);
     const [discordWebhookUrl, setDiscordWebhookUrl] = useState("");
-    const [notificationEnabled, setNotificationEnabled] = useState(true);
+    const [telegramBotToken, setTelegramBotToken] = useState("");
+    const [telegramChatId, setTelegramChatId] = useState("");
+    const [email, setEmail] = useState("");
+    const [slackWebhookUrl, setSlackWebhookUrl] = useState("");
     const [notificationLoading, setNotificationLoading] = useState(false);
     const [notificationError, setNotificationError] = useState(null);
     const [notificationSuccess, setNotificationSuccess] = useState(null);
-    const [testingWebhook, setTestingWebhook] = useState(false);
+    const [testingChannels, setTestingChannels] = useState(false);
+    const [settingUpEmail, setSettingUpEmail] = useState(false);
+    const [sendingDigest, setSendingDigest] = useState(false);
 
-    // Load addresses and notification config on mount
     useEffect(() => {
         async function fetchData() {
             try {
                 setLoading(true);
 
-                // Fetch addresses
                 const addressData = await getAddresses();
                 setAddresses(addressData);
                 if (addressData.length > 0) {
                     setSelectedAddressId(addressData[0].id);
                 }
 
-                // Fetch notification config
                 const configData = await getNotificationConfig();
-                setNotificationConfig(configData);
-                setDiscordWebhookUrl(configData.discord_webhook_url || "");
                 setNotificationEnabled(
                     configData.notification_enabled !== false,
                 );
+                setDiscordWebhookUrl(configData.discord_webhook_url || "");
+                setTelegramBotToken(configData.telegram_bot_token || "");
+                setTelegramChatId(configData.telegram_chat_id || "");
+                setEmail(configData.email || "");
+                setSlackWebhookUrl(configData.slack_webhook_url || "");
             } catch (err) {
                 setError(err.message);
                 console.error("Failed to fetch data:", err);
@@ -62,7 +97,6 @@ export default function Alerts() {
         fetchData();
     }, []);
 
-    // Load alerts when address is selected
     useEffect(() => {
         if (!selectedAddressId) {
             setAlerts([]);
@@ -73,7 +107,7 @@ export default function Alerts() {
             try {
                 const data = await getAlerts(selectedAddressId);
                 setAlerts(data);
-                setError(null); // Clear any previous errors
+                setError(null);
             } catch (err) {
                 setError(err.message);
                 console.error("Failed to fetch alerts:", err);
@@ -83,47 +117,43 @@ export default function Alerts() {
         fetchAlerts();
     }, [selectedAddressId]);
 
-    // Handle new alert submission
     async function handleAlertSubmit(data) {
         if (!selectedAddressId) return;
 
         try {
             const newAlert = await createAlert(selectedAddressId, data);
             setAlerts((prev) => [...prev, newAlert]);
-            setError(null); // Clear any previous errors
+            setError(null);
         } catch (err) {
             setError(err.message);
             console.error("Failed to create alert:", err);
         }
     }
 
-    // Toggle alert enabled/disabled
     async function handleToggleAlert(alertId, currentStatus) {
         try {
             const updated = await updateAlertStatus(alertId, !currentStatus);
             setAlerts((prev) =>
                 prev.map((alert) => (alert.id === alertId ? updated : alert)),
             );
-            setError(null); // Clear any previous errors
+            setError(null);
         } catch (err) {
             setError(err.message);
             console.error("Failed to update alert:", err);
         }
     }
 
-    // Delete alert
     async function handleDeleteAlert(alertId) {
         try {
             await deleteAlert(alertId);
             setAlerts((prev) => prev.filter((alert) => alert.id !== alertId));
-            setError(null); // Clear any previous errors
+            setError(null);
         } catch (err) {
             setError(err.message);
             console.error("Failed to delete alert:", err);
         }
     }
 
-    // Save notification config
     async function handleSaveNotificationConfig() {
         try {
             setNotificationLoading(true);
@@ -131,15 +161,16 @@ export default function Alerts() {
             setNotificationSuccess(null);
 
             const config = {
-                discord_webhook_url: discordWebhookUrl || null,
                 notification_enabled: notificationEnabled,
+                discord_webhook_url: discordWebhookUrl || null,
+                telegram_bot_token: telegramBotToken || null,
+                telegram_chat_id: telegramChatId || null,
+                email: email || null,
+                slack_webhook_url: slackWebhookUrl || null,
             };
 
-            const updated = await updateNotificationConfig(config);
+            await updateNotificationConfig(config);
-            setNotificationConfig(updated);
             setNotificationSuccess("Notification settings saved!");
-
-            // Clear success message after 3 seconds
             setTimeout(() => setNotificationSuccess(null), 3000);
         } catch (err) {
             setNotificationError(err.message);
@@ -149,32 +180,76 @@ export default function Alerts() {
         }
     }
 
-    // Test Discord webhook
+    async function handleTestChannels() {
-    async function handleTestWebhook() {
-        if (!discordWebhookUrl) {
-            setNotificationError("Please enter a Discord webhook URL first");
-            return;
-        }
-
         try {
-            setTestingWebhook(true);
+            setTestingChannels(true);
             setNotificationError(null);
             setNotificationSuccess(null);
 
-            const success = await testDiscordWebhook(discordWebhookUrl);
+            const data = await testNotificationChannels();
+            const results = data.results || [];
 
-            if (success) {
+            const failed = results.filter((r) => !r.success);
+            const succeeded = results.filter((r) => r.success);
+
+            if (failed.length === 0 && succeeded.length > 0) {
                 setNotificationSuccess(
-                    "Test notification sent! Check your Discord channel.",
+                    `Test sent to: ${succeeded.map((r) => r.channel).join(", ")}`,
+                );
+            } else if (failed.length > 0 && succeeded.length > 0) {
+                setNotificationSuccess(
+                    `Sent: ${succeeded.map((r) => r.channel).join(", ")}. Failed: ${failed.map((r) => `${r.channel} (${r.error})`).join(", ")}`,
+                );
+            } else if (failed.length > 0) {
+                setNotificationError(
+                    `Test failed: ${failed.map((r) => `${r.channel} (${r.error})`).join(", ")}`,
+                );
+            }
+
+            setTimeout(() => {
+                setNotificationSuccess(null);
+                setNotificationError(null);
+            }, 6000);
+        } catch (err) {
+            setNotificationError(err.message);
+        } finally {
+            setTestingChannels(false);
+        }
+    }
+
+    async function handleSetupEmail() {
+        try {
+            setSettingUpEmail(true);
+            setNotificationError(null);
+            setNotificationSuccess(null);
+
+            await handleSaveNotificationConfig();
+
+            const result = await setupEmail();
+            setNotificationSuccess(
+                result.message || "Confirmation email sent!",
             );
             setTimeout(() => setNotificationSuccess(null), 5000);
-            } else {
-                setNotificationError("Test failed. Check your webhook URL.");
-            }
         } catch (err) {
-            setNotificationError("Test failed: " + err.message);
+            setNotificationError(err.message);
         } finally {
-            setTestingWebhook(false);
+            setSettingUpEmail(false);
+        }
+    }
+
+    async function handleSendDigest() {
+        try {
+            setSendingDigest(true);
+            setNotificationError(null);
+            setNotificationSuccess(null);
+
+            const result = await sendEmailDigest();
+            setNotificationSuccess(result.message || "Digest email sent!");
+            setTimeout(() => setNotificationSuccess(null), 5000);
+        } catch (err) {
+            setNotificationError(err.message);
+        } finally {
+            setSendingDigest(false);
         }
     }
 
@@ -201,19 +276,18 @@ export default function Alerts() {
                 Alert Rules & Notifications
             </h1>
 
-            {/* Two-column layout */}
             <div
                 style={{
                     display: "grid",
                     gridTemplateColumns: "1fr 1fr",
                     gap: "2rem",
+                    alignItems: "start",
                 }}
             >
                 {/* LEFT COLUMN: Alert Rules */}
                 <div>
                     <h2 style={{ marginTop: 0 }}>Alert Rules</h2>
 
-                    {/* Address selector */}
                     <div style={{ marginBottom: "2rem" }}>
                         <label
                             style={{ display: "block", marginBottom: "0.5rem" }}
@@ -245,7 +319,6 @@ export default function Alerts() {
 
                     {selectedAddress && (
                         <>
-                            {/* Current address info */}
                             <div
                                 style={{
                                     padding: "1rem",
@@ -282,13 +355,11 @@ export default function Alerts() {
                                 </div>
                             </div>
 
-                            {/* Alert creation form */}
                             <div style={{ marginBottom: "2rem" }}>
                                 <h3>Create New Alert</h3>
                                 <AlertForm onSubmit={handleAlertSubmit} />
                             </div>
 
-                            {/* Existing alerts list */}
                             <div>
                                 <h3>Active Alert Rules</h3>
                                 {error && (
@@ -449,7 +520,7 @@ export default function Alerts() {
                     {/* Master toggle */}
                     <div
                         style={{
-                            marginBottom: "2rem",
+                            marginBottom: "1.5rem",
                             padding: "1rem",
                             backgroundColor: "#333",
                             borderRadius: "4px",
@@ -490,17 +561,146 @@ export default function Alerts() {
                         </div>
                     </div>
 
-                    {/* Discord Section */}
+                    {/* All channel settings — hidden when master toggle is off */}
-                    <div style={{ marginBottom: "2rem" }}>
+                    <div
-                        <h3 style={{ marginBottom: "1rem" }}>Discord</h3>
-
-                        <div style={{ marginBottom: "1rem" }}>
-                            <label
                         style={{
-                                    display: "block",
+                            display: notificationEnabled ? "block" : "none",
-                                    marginBottom: "0.5rem",
                         }}
                     >
+                        {/* Telegram */}
+                        <div style={sectionStyle}>
+                            <h3 style={{ marginTop: 0, marginBottom: "1rem" }}>
+                                Telegram
+                            </h3>
+
+                            <div style={{ marginBottom: "0.75rem" }}>
+                                <label style={labelStyle}>Bot Token</label>
+                                <input
+                                    type="text"
+                                    value={telegramBotToken}
+                                    onChange={(e) =>
+                                        setTelegramBotToken(e.target.value)
+                                    }
+                                    placeholder="123456789:ABCdefGHIjklMNOpqrSTUvwxYZ"
+                                    style={inputStyle}
+                                />
+                            </div>
+
+                            <div style={{ marginBottom: "0.5rem" }}>
+                                <label style={labelStyle}>Chat ID</label>
+                                <input
+                                    type="text"
+                                    value={telegramChatId}
+                                    onChange={(e) =>
+                                        setTelegramChatId(e.target.value)
+                                    }
+                                    placeholder="-1001234567890"
+                                    style={inputStyle}
+                                />
+                            </div>
+
+                            <a
+                                href="https://core.telegram.org/bots#how-do-i-create-a-bot"
+                                target="_blank"
+                                rel="noopener noreferrer"
+                                style={helpLinkStyle}
+                            >
+                                How to create a Telegram bot & get your Chat ID
+                            </a>
+                        </div>
+
+                        {/* Email */}
+                        <div style={sectionStyle}>
+                            <h3 style={{ marginTop: 0, marginBottom: "1rem" }}>
+                                Email
+                            </h3>
+
+                            <div style={{ marginBottom: "0.75rem" }}>
+                                <label style={labelStyle}>Email Address</label>
+                                <input
+                                    type="email"
+                                    value={email}
+                                    onChange={(e) => setEmail(e.target.value)}
+                                    placeholder="you@example.com"
+                                    style={inputStyle}
+                                />
+                            </div>
+
+                            <div
+                                style={{
+                                    fontSize: "0.85rem",
+                                    color: "#808080",
+                                    marginBottom: "0.75rem",
+                                }}
+                            >
+                                Alert notifications and digests will be sent to
+                                this address
+                            </div>
+
+                            <div
+                                style={{
+                                    display: "flex",
+                                    gap: "0.5rem",
+                                }}
+                            >
+                                <button
+                                    onClick={handleSetupEmail}
+                                    disabled={settingUpEmail || !email}
+                                    style={{
+                                        padding: "0.5rem 1rem",
+                                        fontSize: "0.85rem",
+                                        backgroundColor:
+                                            settingUpEmail || !email
+                                                ? "#333"
+                                                : "#0066cc",
+                                        color: "white",
+                                        border: "none",
+                                        borderRadius: "4px",
+                                        cursor:
+                                            settingUpEmail || !email
+                                                ? "not-allowed"
+                                                : "pointer",
+                                    }}
+                                >
+                                    {settingUpEmail
+                                        ? "Setting up..."
+                                        : "Verify Email"}
+                                </button>
+
+                                <button
+                                    onClick={handleSendDigest}
+                                    disabled={sendingDigest || !email}
+                                    style={{
+                                        padding: "0.5rem 1rem",
+                                        fontSize: "0.85rem",
+                                        backgroundColor:
+                                            sendingDigest || !email
+                                                ? "#333"
+                                                : "#6c757d",
+                                        color: "white",
+                                        border: "none",
+                                        borderRadius: "4px",
+                                        cursor:
+                                            sendingDigest || !email
+                                                ? "not-allowed"
+                                                : "pointer",
+                                    }}
+                                >
+                                    {sendingDigest
+                                        ? "Sending..."
+                                        : "Send Digest Now"}
+                                </button>
+                            </div>
+                        </div>
+
+                        {/* Discord */}
+                        <div style={sectionStyle}>
+                            <h3 style={{ marginTop: 0, marginBottom: "1rem" }}>
+                                Discord
+                            </h3>
+
+                            <div style={{ marginBottom: "0.5rem" }}>
+                                <label style={labelStyle}>
                                     Discord Webhook URL
                                 </label>
                                 <input
@@ -510,37 +710,59 @@ export default function Alerts() {
                                         setDiscordWebhookUrl(e.target.value)
                                     }
                                     placeholder="https://discord.com/api/webhooks/..."
-                                style={{
+                                    style={inputStyle}
-                                    width: "100%",
-                                    padding: "0.5rem",
-                                    fontSize: "1rem",
-                                    backgroundColor: "#1a1a1a",
-                                    border: "1px solid #444",
-                                    borderRadius: "4px",
-                                    color: "white",
-                                    fontFamily: "monospace",
-                                    fontSize: "0.9rem",
-                                }}
                                 />
-                            <div
+                            </div>
-                                style={{
+
-                                    fontSize: "0.978rem",
-                                    color: "#b3b3b3",
-                                    marginTop: "0.5rem",
-                                }}
-                            >
                             <a
                                 href="https://support.discord.com/hc/en-us/articles/228383668-Intro-to-Webhooks"
                                 target="_blank"
                                 rel="noopener noreferrer"
-                                    style={{ color: "#0066cc" }}
+                                style={helpLinkStyle}
                             >
                                 How to get a Discord webhook URL
                             </a>
                         </div>
+
+                        {/* Slack */}
+                        <div style={sectionStyle}>
+                            <h3 style={{ marginTop: 0, marginBottom: "1rem" }}>
+                                Slack
+                            </h3>
+
+                            <div style={{ marginBottom: "0.5rem" }}>
+                                <label style={labelStyle}>
+                                    Slack Webhook URL
+                                </label>
+                                <input
+                                    type="text"
+                                    value={slackWebhookUrl}
+                                    onChange={(e) =>
+                                        setSlackWebhookUrl(e.target.value)
+                                    }
+                                    placeholder="https://hooks.slack.com/services/..."
+                                    style={inputStyle}
+                                />
                             </div>
 
-                        <div style={{ display: "flex", gap: "0.5rem" }}>
+                            <a
+                                href="https://api.slack.com/messaging/webhooks"
+                                target="_blank"
+                                rel="noopener noreferrer"
+                                style={helpLinkStyle}
+                            >
+                                How to set up Slack Incoming Webhooks
+                            </a>
+                        </div>
+
+                        {/* Save & Test buttons at the bottom */}
+                        <div
+                            style={{
+                                display: "flex",
+                                gap: "0.75rem",
+                                marginTop: "1rem",
+                            }}
+                        >
                             <button
                                 onClick={handleSaveNotificationConfig}
                                 disabled={notificationLoading}
@@ -564,67 +786,34 @@ export default function Alerts() {
                             </button>
 
                             <button
-                                onClick={handleTestWebhook}
+                                onClick={handleTestChannels}
-                                disabled={testingWebhook || !discordWebhookUrl}
+                                disabled={testingChannels}
                                 style={{
                                     padding: "0.75rem 1.5rem",
                                     fontSize: "1rem",
-                                    backgroundColor:
+                                    backgroundColor: testingChannels
-                                        testingWebhook || !discordWebhookUrl
                                         ? "#333"
                                         : "#28a745",
                                     color: "white",
                                     border: "none",
                                     borderRadius: "4px",
-                                    cursor:
+                                    cursor: testingChannels
-                                        testingWebhook || !discordWebhookUrl
                                         ? "not-allowed"
                                         : "pointer",
                                 }}
                             >
-                                {testingWebhook ? "Testing..." : "Test Webhook"}
+                                {testingChannels
+                                    ? "Testing..."
+                                    : "Test All Channels"}
                             </button>
                         </div>
                     </div>
-
-                    {/* Telegram Section (Coming Soon) */}
-                    <div style={{ marginBottom: "2rem", opacity: 0.5 }}>
-                        <h3 style={{ marginBottom: "1rem" }}>Telegram</h3>
-                        <div
-                            style={{
-                                padding: "1rem",
-                                backgroundColor: "#333",
-                                borderRadius: "4px",
-                                color: "#999",
-                                textAlign: "center",
-                            }}
-                        >
-                            Coming Soon
-                        </div>
-                    </div>
-
-                    {/* Email Section (Coming Soon) */}
-                    <div style={{ opacity: 0.5 }}>
-                        <h3 style={{ marginBottom: "1rem" }}>Email</h3>
-                        <div
-                            style={{
-                                padding: "1rem",
-                                backgroundColor: "#333",
-                                borderRadius: "4px",
-                                color: "#999",
-                                textAlign: "center",
-                            }}
-                        >
-                            Coming Soon
-                        </div>
-                    </div>
                 </div>
             </div>
         </div>
     );
 }
 
-// Helper to format alert type for display
 function formatAlertType(type) {
     const labels = {
         incoming_tx: "Incoming transaction",