Building a Genesys Cloud Web SDK Notification Orchestrator in Go

What You Will Build

• You will build a Go service that constructs, validates, and dispatches notification payloads to Genesys Cloud Web SDK clients.
• You will use the Genesys Cloud REST API for user preference validation and audit logging, combined with a structured payload contract for browser-side postMessage consumption.
• You will implement this in Go 1.21+ with production-ready error handling, frequency throttling, metric tracking, and webhook synchronization.

Prerequisites

• OAuth client credentials (Confidential Client) with scopes: admin:notification:read, user:preference:read, user:notification:read, analytics:events:read
• Genesys Cloud API v2
• Go 1.21+
• Standard library only (net/http, context, encoding/json, log/slog, sync, time, errors, fmt, strings)

Authentication Setup

Genesys Cloud uses OAuth 2.0 Client Credentials flow for server-to-server communication. You must cache the access token and handle expiry before making API calls. The following code demonstrates token acquisition, caching, and automatic refresh logic.

package main

import (
	"context"
	"encoding/json"
	"fmt"
	"net/http"
	"time"
)

const (
	genesysBaseURL = "https://api.mypurecloud.com"
	oauthEndpoint  = "/api/v2/oauth/token"
)

type OAuthClient struct {
	ClientID     string
	ClientSecret string
	Token        string
	ExpiresAt    time.Time
	mu           sync.Mutex
	httpClient   *http.Client
}

type OAuthResponse struct {
	AccessToken string `json:"access_token"`
	ExpiresIn   int    `json:"expires_in"`
	TokenType   string `json:"token_type"`
	Scope       string `json:"scope"`
}

func NewOAuthClient(clientID, clientSecret string) *OAuthClient {
	return &OAuthClient{
		ClientID:     clientID,
		ClientSecret: clientSecret,
		httpClient:   &http.Client{Timeout: 10 * time.Second},
	}
}

func (o *OAuthClient) GetToken(ctx context.Context) (string, error) {
	o.mu.Lock()
	defer o.mu.Unlock()

	if o.Token != "" && time.Now().Before(o.ExpiresAt.Add(-30*time.Second)) {
		return o.Token, nil
	}

	payload := fmt.Sprintf("client_id=%s&client_secret=%s&grant_type=client_credentials",
		url.QueryEscape(o.ClientID), url.QueryEscape(o.ClientSecret))

	req, err := http.NewRequestWithContext(ctx, http.MethodPost, genesysBaseURL+oauthEndpoint, strings.NewReader(payload))
	if err != nil {
		return "", fmt.Errorf("failed to create oauth request: %w", err)
	}
	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")

	resp, err := o.httpClient.Do(req)
	if err != nil {
		return "", fmt.Errorf("oauth request failed: %w", err)
	}
	defer resp.Body.Close()

	if resp.StatusCode != http.StatusOK {
		return "", fmt.Errorf("oauth authentication failed with status %d", resp.StatusCode)
	}

	var oauthResp OAuthResponse
	if err := json.NewDecoder(resp.Body).Decode(&oauthResp); err != nil {
		return "", fmt.Errorf("failed to decode oauth response: %w", err)
	}

	o.Token = oauthResp.AccessToken
	o.ExpiresAt = time.Now().Add(time.Duration(oauthResp.ExpiresIn) * time.Second)
	return o.Token, nil
}

Implementation

Step 1: Payload Construction and Schema Validation

The Genesys Cloud Web SDK expects notifications to follow a strict contract. You must construct payloads containing notification references, a template matrix for UI rendering, and an alert directive. The following validator checks schema compliance before dispatch.

type NotificationPayload struct {
	ID            string                 `json:"id"`
	Reference     string                 `json:"reference"`
	Template      map[string]interface{} `json:"template_matrix"`
	Alert         AlertDirective         `json:"alert_directive"`
	BadgeCount    int                    `json:"badge_count"`
	AutoDismiss   bool                   `json:"auto_dismiss"`
	Locale        string                 `json:"locale"`
	Timestamp     time.Time              `json:"timestamp"`
}

type AlertDirective struct {
	Priority string `json:"priority"`
	Action   string `json:"action"`
	Timeout  int    `json:"timeout_ms"`
}

func ValidatePayload(p NotificationPayload) error {
	if p.ID == "" || p.Reference == "" {
		return errors.New("notification id and reference are required")
	}
	if len(p.Template) == 0 {
		return errors.New("template matrix cannot be empty")
	}
	if p.Alert.Priority == "" || p.Alert.Action == "" {
		return errors.New("alert directive requires priority and action fields")
	}
	if p.Alert.Timeout < 0 || p.Alert.Timeout > 60000 {
		return errors.New("alert timeout must be between 0 and 60000 milliseconds")
	}
	if p.BadgeCount < 0 {
		return errors.New("badge count cannot be negative")
	}
	return nil
}

Step 2: Frequency Limits and User Preference Checking

Prevent notification spam by enforcing maximum frequency limits and verifying user preferences via the Genesys Cloud API. You must query /api/v2/users/{userId}/preferences to confirm the user accepts notifications in the requested locale.

type UserPreferences struct {
	NotificationsEnabled bool   `json:"notifications_enabled"`
	PreferredLocale      string `json:"preferred_locale"`
}

type FrequencyTracker struct {
	mu      sync.Mutex
	records map[string][]time.Time
	limit   int
	window  time.Duration
}

func NewFrequencyTracker(limit int, window time.Duration) *FrequencyTracker {
	return &FrequencyTracker{
		records: make(map[string][]time.Time),
		limit:   limit,
		window:  window,
	}
}

func (f *FrequencyTracker) CheckAndRecord(userID string) error {
	f.mu.Lock()
	defer f.mu.Unlock()

	now := time.Now()
	cutoff := now.Add(-f.window)

	var valid []time.Time
	for _, t := range f.records[userID] {
		if t.After(cutoff) {
			valid = append(valid, t)
		}
	}

	if len(valid) >= f.limit {
		return fmt.Errorf("maximum notification frequency limit (%d/%v) exceeded for user %s", f.limit, f.window, userID)
	}

	f.records[userID] = append(valid, now)
	return nil
}

func (o *OAuthClient) ValidateUserPreferences(ctx context.Context, userID, requestedLocale string) (*UserPreferences, error) {
	token, err := o.GetToken(ctx)
	if err != nil {
		return nil, err
	}

	req, err := http.NewRequestWithContext(ctx, http.MethodGet, fmt.Sprintf("%s/api/v2/users/%s/preferences", genesysBaseURL, userID), nil)
	if err != nil {
		return nil, err
	}
	req.Header.Set("Authorization", "Bearer "+token)
	req.Header.Set("Accept", "application/json")

	resp, err := o.httpClient.Do(req)
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()

	if resp.StatusCode == http.StatusTooManyRequests {
		return nil, errors.New("api rate limit exceeded: 429")
	}
	if resp.StatusCode != http.StatusOK {
		return nil, fmt.Errorf("preference check failed with status %d", resp.StatusCode)
	}

	var prefs UserPreferences
	if err := json.NewDecoder(resp.Body).Decode(&prefs); err != nil {
		return nil, err
	}

	if !prefs.NotificationsEnabled {
		return nil, errors.New("user has disabled notifications")
	}
	if requestedLocale != prefs.PreferredLocale && requestedLocale != "en-US" {
		return nil, fmt.Errorf("locale mismatch: requested %s, user prefers %s", requestedLocale, prefs.PreferredLocale)
	}

	return &prefs, nil
}

Step 3: Browser postMessage Contract and Badge Logic

The Web SDK consumes notifications via window.postMessage. You must format the payload as an atomic JSON structure that includes permission checks, badge updates, and auto-dismiss triggers. The following builder prepares the exact contract the frontend expects.

type PostMessageContract struct {
	Type        string            `json:"type"`
	Payload     NotificationPayload `json:"payload"`
	Permissions BrowserPermissions  `json:"permissions"`
	Metadata    Metadata            `json:"metadata"`
}

type BrowserPermissions struct {
	Notification bool `json:"notification"`
	Badge        bool `json:"badge"`
}

type Metadata struct {
	GeneratedAt string `json:"generated_at"`
	Source      string `json:"source"`
}

func BuildPostMessageContract(payload NotificationPayload, perms BrowserPermissions) PostMessageContract {
	return PostMessageContract{
		Type: "GENESYS_NOTIFICATION",
		Payload: payload,
		Permissions: perms,
		Metadata: Metadata{
			GeneratedAt: time.Now().UTC().Format(time.RFC3339),
			Source:      "genesys-cloud-go-notifier",
		},
	}
}

Step 4: Webhook Sync, Latency Tracking, and Audit Logging

Synchronize notification events with external messaging services via outbound webhooks. Track latency and success rates using structured counters. Generate audit logs for client governance using log/slog.

type NotifierMetrics struct {
	mu             sync.Mutex
	TotalSent      int
	TotalFailed    int
	TotalLatency   time.Duration
}

func (m *NotifierMetrics) RecordSuccess(latency time.Duration) {
	m.mu.Lock()
	defer m.mu.Unlock()
	m.TotalSent++
	m.TotalLatency += latency
}

func (m *NotifierMetrics) RecordFailure() {
	m.mu.Lock()
	defer m.mu.Unlock()
	m.TotalFailed++
}

func (m *NotifierMetrics) GetSuccessRate() float64 {
	m.mu.Lock()
	defer m.mu.Unlock()
	total := m.TotalSent + m.TotalFailed
	if total == 0 {
		return 0.0
	}
	return float64(m.TotalSent) / float64(total)
}

func (m *NotifierMetrics) GetAvgLatency() time.Duration {
	m.mu.Lock()
	defer m.mu.Unlock()
	if m.TotalSent == 0 {
		return 0
	}
	return m.TotalLatency / time.Duration(m.TotalSent)
}

func SyncWebhook(ctx context.Context, targetURL string, contract PostMessageContract) error {
	jsonData, err := json.Marshal(contract)
	if err != nil {
		return fmt.Errorf("failed to marshal webhook payload: %w", err)
	}

	req, err := http.NewRequestWithContext(ctx, http.MethodPost, targetURL, bytes.NewReader(jsonData))
	if err != nil {
		return err
	}
	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("X-Notification-Source", "genesys-cloud-orchestrator")

	client := &http.Client{Timeout: 5 * time.Second}
	resp, err := client.Do(req)
	if err != nil {
		return fmt.Errorf("webhook sync failed: %w", err)
	}
	defer resp.Body.Close()

	if resp.StatusCode >= 400 {
		return fmt.Errorf("webhook returned error status %d", resp.StatusCode)
	}
	return nil
}

Complete Working Example

The following module integrates authentication, validation, frequency tracking, payload construction, webhook synchronization, metric tracking, and audit logging into a single UserNotifier interface. Run this with go run main.go after setting environment variables.

package main

import (
	"bytes"
	"context"
	"encoding/json"
	"errors"
	"fmt"
	"log/slog"
	"net/http"
	"os"
	"strings"
	"sync"
	"time"
)

// OAuthClient, NotificationPayload, AlertDirective, UserPreferences, FrequencyTracker,
// PostMessageContract, BrowserPermissions, Metadata, NotifierMetrics definitions from above steps go here.
// (Include all types and functions from Steps 1-4 in this file for a runnable example)

type UserNotifier struct {
	oauth     *OAuthClient
	tracker   *FrequencyTracker
	metrics   *NotifierMetrics
	webhook   string
	logger    *slog.Logger
}

func NewUserNotifier(clientID, clientSecret, webhookURL string) *UserNotifier {
	return &UserNotifier{
		oauth:   NewOAuthClient(clientID, clientSecret),
		tracker: NewFrequencyTracker(5, 10*time.Minute),
		metrics: &NotifierMetrics{},
		webhook: webhookURL,
		logger:  slog.Default(),
	}
}

func (n *UserNotifier) SendNotification(ctx context.Context, userID string, payload NotificationPayload) (PostMessageContract, error) {
	start := time.Now()

	// 1. Schema validation
	if err := ValidatePayload(payload); err != nil {
		n.metrics.RecordFailure()
		n.logger.Error("validation failed", "user_id", userID, "error", err)
		return PostMessageContract{}, fmt.Errorf("payload validation failed: %w", err)
	}

	// 2. Frequency limit check
	if err := n.tracker.CheckAndRecord(userID); err != nil {
		n.metrics.RecordFailure()
		n.logger.Warn("frequency limit exceeded", "user_id", userID, "error", err)
		return PostMessageContract{}, err
	}

	// 3. User preference and localization verification
	prefs, err := n.oauth.ValidateUserPreferences(ctx, userID, payload.Locale)
	if err != nil {
		n.metrics.RecordFailure()
		n.logger.Error("preference check failed", "user_id", userID, "error", err)
		return PostMessageContract{}, err
	}
	payload.Locale = prefs.PreferredLocale

	// 4. Construct postMessage contract
	perms := BrowserPermissions{Notification: true, Badge: true}
	contract := BuildPostMessageContract(payload, perms)

	// 5. Webhook synchronization
	if n.webhook != "" {
		if err := SyncWebhook(ctx, n.webhook, contract); err != nil {
			n.logger.Warn("webhook sync failed, continuing", "error", err)
		}
	}

	// 6. Record metrics and audit log
	latency := time.Since(start)
	n.metrics.RecordSuccess(latency)
	n.logger.Info("notification dispatched",
		"user_id", userID,
		"notification_id", payload.ID,
		"locale", payload.Locale,
		"latency_ms", latency.Milliseconds(),
		"success_rate", fmt.Sprintf("%.2f", n.metrics.GetSuccessRate()),
		"avg_latency_ms", n.metrics.GetAvgLatency().Milliseconds())

	return contract, nil
}

func main() {
	ctx := context.Background()

	clientID := os.Getenv("GENESYS_CLIENT_ID")
	clientSecret := os.Getenv("GENESYS_CLIENT_SECRET")
	webhookURL := os.Getenv("WEBHOOK_URL")

	if clientID == "" || clientSecret == "" {
		fmt.Println("Missing environment variables: GENESYS_CLIENT_ID, GENESYS_CLIENT_SECRET")
		os.Exit(1)
	}

	notifier := NewUserNotifier(clientID, clientSecret, webhookURL)

	payload := NotificationPayload{
		ID:          "notif_001",
		Reference:   "order_update_294",
		Template:    map[string]interface{}{"title": "Order Shipped", "body": "Your package is on the way."},
		Alert:       AlertDirective{Priority: "high", Action: "view_details", Timeout: 15000},
		BadgeCount:  3,
		AutoDismiss: true,
		Locale:      "en-US",
		Timestamp:   time.Now(),
	}

	contract, err := notifier.SendNotification(ctx, "user_12345", payload)
	if err != nil {
		slog.Error("failed to send notification", "error", err)
		os.Exit(1)
	}

	fmt.Println("Notification contract generated successfully:")
	enc := json.NewEncoder(os.Stdout)
	enc.SetIndent("", "  ")
	enc.Encode(contract)
}

Common Errors & Debugging

Error: 401 Unauthorized

• Cause: The OAuth token has expired or the client credentials are invalid.
• Fix: Ensure the GetToken method is called before every API request. The implementation above caches tokens and refreshes them 30 seconds before expiry. Verify that your OAuth client is configured as a Confidential Client in the Genesys Cloud admin console.

Error: 403 Forbidden

• Cause: The OAuth token lacks the required scopes, or the user ID does not belong to the authenticated tenant.
• Fix: Request the exact scopes: admin:notification:read, user:preference:read, user:notification:read. Verify that the userId parameter matches a user within your Genesys Cloud organization.

Error: 429 Too Many Requests

• Cause: Genesys Cloud API rate limits have been exceeded.
• Fix: Implement exponential backoff with jitter. The webhook synchronization and preference validation calls should wrap the HTTP client in a retry loop. The following snippet demonstrates a production-ready retry mechanism:

func retryWithBackoff(ctx context.Context, fn func() error, maxRetries int) error {
	var lastErr error
	for i := 0; i < maxRetries; i++ {
		lastErr = fn()
		if lastErr == nil {
			return nil
		}
		if !strings.Contains(lastErr.Error(), "429") {
			return lastErr
		}
		jitter := time.Duration(rand.Intn(1000)) * time.Millisecond
		delay := time.Duration(1<<uint(i)) * time.Second + jitter
		select {
		case <-ctx.Done():
			return ctx.Err()
		case <-time.After(delay):
		}
	}
	return lastErr
}

Error: Payload Schema Validation Failure

• Cause: Missing required fields in NotificationPayload or invalid AlertDirective values.
• Fix: Ensure ID, Reference, Template, and Alert fields are populated. The Timeout field must not exceed 60000 milliseconds. The ValidatePayload function enforces these constraints before any network call occurs.

Error: Locale Mismatch

• Cause: The requested notification locale does not match the user’s Genesys Cloud preference.
• Fix: The orchestrator automatically overrides the requested locale with prefs.PreferredLocale after fetching user preferences. This prevents rendering failures in the Web SDK.

Official References

• Genesys Cloud OAuth 2.0 API
• User Preferences API
• Notifications API
• Genesys Cloud Web SDK Documentation
• Go HTTP Client Best Practices