Sending Genesys Cloud Webchat Bot Messages via WebSocket with Go

Sending Genesys Cloud Webchat Bot Messages via WebSocket with Go

What You Will Build

A production-ready Go module that connects to Genesys Cloud Webchat v3, constructs and validates bot message payloads with interaction ID references, card matrices, and action button directives, enforces client constraints and maximum size limits, manages atomic sequence-numbered transmission, tracks latency and delivery rates, synchronizes with external analytics via callbacks, generates structured audit logs, and exposes a type-safe sender interface for automated chat management.

Prerequisites

  • Go 1.21 or later
  • OAuth 2.0 Client Credentials grant with webchat:urls:write scope
  • gorilla/websocket v1.5.0+
  • github.com/go-playground/validator/v10 v10.12.0+
  • Genesys Cloud environment ID and valid client credentials
  • Standard library packages: context, crypto/tls, encoding/json, log/slog, net/http, sync, sync/atomic, time, fmt

Authentication Setup

Genesys Cloud Webchat does not accept OAuth tokens directly over the WebSocket connection. You must first exchange client credentials for an access token, then request a temporary Webchat URL. The URL generation endpoint enforces rate limits and returns a 429 status when thresholds are exceeded. The following code implements a retryable REST client for token acquisition and URL generation.

package main

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

type OAuthTokenResponse struct {
	AccessToken string `json:"access_token"`
	TokenType   string `json:"token_type"`
	ExpiresIn   int64  `json:"expires_in"`
}

type WebchatURLResponse struct {
	URL string `json:"url"`
}

func getOAuthToken(ctx context.Context, envID, clientID, clientSecret string) (*OAuthTokenResponse, error) {
	url := fmt.Sprintf("https://%s.mypurecloud.com/oauth/token", envID)
	payload := fmt.Sprintf(`{"grant_type":"client_credentials","client_id":"%s","client_secret":"%s"}`, clientID, clientSecret)

	client := &http.Client{
		Timeout: 10 * time.Second,
		Transport: &http.Transport{
			TLSClientConfig: &tls.Config{MinVersion: tls.VersionTLS12},
		},
	}

	var tokenResp OAuthTokenResponse
	var lastErr error

	// Retry logic for 429 rate limiting
	for attempt := 0; attempt < 3; attempt++ {
		req, err := http.NewRequestWithContext(ctx, http.MethodPost, url, nil)
		if err != nil {
			return nil, fmt.Errorf("failed to create token request: %w", err)
		}
		req.Header.Set("Content-Type", "application/json")
		req.Header.Set("Authorization", "Basic "+base64Encode(clientID+":"+clientSecret))

		resp, err := client.Do(req)
		if err != nil {
			lastErr = fmt.Errorf("token request failed: %w", err)
			continue
		}
		defer resp.Body.Close()

		if resp.StatusCode == http.StatusTooManyRequests {
			retryAfter := 2 * time.Second
			time.Sleep(retryAfter)
			lastErr = fmt.Errorf("token endpoint rate limited")
			continue
		}

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

		if err := json.NewDecoder(resp.Body).Decode(&tokenResp); err != nil {
			lastErr = fmt.Errorf("failed to decode token response: %w", err)
			continue
		}
		return &tokenResp, nil
	}

	return nil, fmt.Errorf("exhausted retries for token: %w", lastErr)
}

func getWebchatURL(ctx context.Context, envID, token string) (string, error) {
	url := fmt.Sprintf("https://%s.mypurecloud.com/api/v2/webchat/urls", envID)
	payload := `{"name":"BotIntegration","description":"Automated Webchat Sender"}`

	client := &http.Client{Timeout: 10 * time.Second}

	var urlResp WebchatURLResponse
	var lastErr error

	for attempt := 0; attempt < 3; attempt++ {
		req, err := http.NewRequestWithContext(ctx, http.MethodPost, url, nil)
		if err != nil {
			return "", fmt.Errorf("failed to create url request: %w", err)
		}
		req.Header.Set("Content-Type", "application/json")
		req.Header.Set("Authorization", "Bearer "+token)
		req.Body = httpBody(payload)

		resp, err := client.Do(req)
		if err != nil {
			lastErr = fmt.Errorf("url request failed: %w", err)
			continue
		}
		defer resp.Body.Close()

		if resp.StatusCode == http.StatusTooManyRequests {
			time.Sleep(2 * time.Second)
			lastErr = fmt.Errorf("url endpoint rate limited")
			continue
		}

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

		if err := json.NewDecoder(resp.Body).Decode(&urlResp); err != nil {
			lastErr = fmt.Errorf("failed to decode url response: %w", err)
			continue
		}
		return urlResp.URL, nil
	}

	return "", fmt.Errorf("exhausted retries for webchat url: %w", lastErr)
}

func httpBody(s string) io.ReadCloser {
	return io.NopCloser(strings.NewReader(s))
}

func base64Encode(s string) string {
	return base64.StdEncoding.EncodeToString([]byte(s))
}

Implementation

Step 1: WebSocket Connection and Session State Verification

The Webchat v3 protocol requires a persistent WebSocket connection. You must verify the session state before transmitting messages. The connection handler maintains a connected flag and a write mutex to prevent concurrent frame corruption.

package main

import (
	"context"
	"fmt"
	"log/slog"
	"sync"
	"time"

	"github.com/gorilla/websocket"
)

type WebchatSession struct {
	conn     *websocket.Conn
	mu       sync.Mutex
	connected bool
	seq      uint64
	logger   *slog.Logger
}

func NewWebchatSession(ctx context.Context, wsURL string) (*WebchatSession, error) {
	dialer := websocket.Dialer{
		HandshakeTimeout: 10 * time.Second,
	}

	conn, resp, err := dialer.DialContext(ctx, wsURL, nil)
	if err != nil {
		return nil, fmt.Errorf("websocket dial failed: %w", err)
	}
	defer resp.Body.Close()

	session := &WebchatSession{
		conn:    conn,
		connected: true,
		logger:  slog.Default(),
	}

	// Start ping/pong keepalive
	go session.keepAlive()

	return session, nil
}

func (s *WebchatSession) keepAlive() {
	ticker := time.NewTicker(30 * time.Second)
	defer ticker.Stop()

	for range ticker.C {
		if !s.IsConnected() {
			return
		}
		s.mu.Lock()
		err := s.conn.WriteMessage(websocket.TextMessage, []byte(`{"type":"ping"}`))
		s.mu.Unlock()
		if err != nil {
			s.connected = false
			s.logger.Error("keepalive failed", "error", err)
			return
		}
	}
}

func (s *WebchatSession) IsConnected() bool {
	s.mu.Lock()
	defer s.mu.Unlock()
	return s.connected
}

Step 2: Payload Construction and Schema Validation

Genesys Cloud Webchat clients enforce strict schema constraints. Messages must not exceed 10,240 bytes. Cards require valid type matrices, and buttons must contain explicit action directives. The following struct and validator enforce these rules before transmission.

package main

import (
	"encoding/json"
	"fmt"

	"github.com/go-playground/validator/v10"
)

type Card struct {
	Type        string   `json:"type" validate:"required,oneof=info action"`
	Title       string   `json:"title,omitempty" validate:"max=100"`
	Description string   `json:"description,omitempty" validate:"max=500"`
	ImageURL    string   `json:"image_url,omitempty" validate:"omitempty,url"`
}

type Button struct {
	Type      string `json:"type" validate:"required,oneof=postback submit"`
	Label     string `json:"label" validate:"required,max=50"`
	Payload   string `json:"payload" validate:"required,max=200"`
	Action    string `json:"action" validate:"required,oneof=url postback"`
}

type WebchatMessage struct {
	Type          string   `json:"type" validate:"required,eq=message"`
	Direction     string   `json:"direction" validate:"required,eq=inbound"`
	InteractionID string   `json:"interactionId" validate:"required,uuid"`
	ConversationID string  `json:"conversationId" validate:"required,uuid"`
	MessageID     string   `json:"messageId" validate:"required,uuid"`
	Text          string   `json:"text,omitempty" validate:"max=4000"`
	Cards         []Card   `json:"cards,omitempty" validate:"dive"`
	Buttons       []Button `json:"buttons,omitempty" validate:"dive,max=10"`
	Seq           uint64   `json:"seq"`
	Timestamp     string   `json:"timestamp"`
}

var validate = validator.New()

func ValidatePayload(msg WebchatMessage) error {
	if err := validate.Struct(msg); err != nil {
		return fmt.Errorf("schema validation failed: %w", err)
	}

	payloadBytes, err := json.Marshal(msg)
	if err != nil {
		return fmt.Errorf("json marshal failed: %w", err)
	}

	// Genesys client constraint: maximum 10KB per frame
	if len(payloadBytes) > 10240 {
		return fmt.Errorf("payload size %d bytes exceeds 10240 byte limit", len(payloadBytes))
	}

	return nil
}

Step 3: Atomic Transmission and Sequence Management

WebSocket writes are not thread-safe in Go. You must serialize writes using a mutex and increment sequence numbers atomically. The sender wraps the transmission in a single critical section to guarantee frame integrity.

package main

import (
	"context"
	"encoding/json"
	"fmt"
	"log/slog"
	"sync/atomic"
	"time"
)

type SendMetrics struct {
	TotalSent      uint64
	TotalFailed    uint64
	AvgLatencyMS   float64
	LastSendTime   time.Time
}

type WebchatSender struct {
	session *WebchatSession
	metrics *SendMetrics
	logger  *slog.Logger
}

func NewWebchatSender(session *WebchatSession) *WebchatSender {
	return &WebchatSender{
		session: session,
		metrics: &SendMetrics{},
		logger:  slog.Default(),
	}
}

func (s *WebchatSender) Send(ctx context.Context, msg WebchatMessage) error {
	if !s.session.IsConnected() {
		return fmt.Errorf("session disconnected")
	}

	// Assign sequence and timestamp
	msg.Seq = atomic.AddUint64(&s.session.seq, 1)
	msg.Timestamp = time.Now().UTC().Format(time.RFC3339Nano)

	if err := ValidatePayload(msg); err != nil {
		return fmt.Errorf("payload validation failed: %w", err)
	}

	start := time.Now()
	s.session.mu.Lock()
	defer s.session.mu.Unlock()

	payload, err := json.Marshal(msg)
	if err != nil {
		return fmt.Errorf("payload serialization failed: %w", err)
	}

	err = s.session.conn.WriteMessage(websocket.TextMessage, payload)
	latency := time.Since(start)

	if err != nil {
		atomic.AddUint64(&s.metrics.TotalFailed, 1)
		s.logger.Error("transmission failed", "seq", msg.Seq, "latency_ms", latency.Milliseconds(), "error", err)
		return fmt.Errorf("websocket write failed: %w", err)
	}

	atomic.AddUint64(&s.metrics.TotalSent, 1)
	s.metrics.LastSendTime = time.Now()
	s.metrics.AvgLatencyMS = float64(latency.Milliseconds())

	s.logger.Info("message sent", "seq", msg.Seq, "latency_ms", latency.Milliseconds())
	return nil
}

Step 4: Analytics Callbacks, Latency Tracking, and Audit Logging

Production systems require external analytics synchronization and governance audit trails. The sender exposes callback hooks that fire after successful transmission. Latency and delivery rates are aggregated in memory, while structured logs capture interaction governance data.

package main

import (
	"context"
	"encoding/json"
	"fmt"
	"log/slog"
	"time"
)

type AnalyticsCallback func(event map[string]interface{})
type AuditLogCallback func(entry map[string]interface{})

type ConfiguredSender struct {
	*WebchatSender
	analyticsCb AnalyticsCallback
	auditCb     AuditLogCallback
}

func NewConfiguredSender(sess *WebchatSession, analyticsCb AnalyticsCallback, auditCb AuditLogCallback) *ConfiguredSender {
	return &ConfiguredSender{
		WebchatSender: NewWebchatSender(sess),
		analyticsCb:   analyticsCb,
		auditCb:       auditCb,
	}
}

func (s *ConfiguredSender) Send(ctx context.Context, msg WebchatMessage) error {
	err := s.WebchatSender.Send(ctx, msg)
	
	auditEntry := map[string]interface{}{
		"timestamp":    time.Now().UTC().Format(time.RFC3339Nano),
		"interactionId": msg.InteractionID,
		"conversationId": msg.ConversationID,
		"messageId":    msg.MessageID,
		"seq":          msg.Seq,
		"status":       "failed",
		"error":        "",
	}

	if err == nil {
		auditEntry["status"] = "success"
		
		analyticsEvent := map[string]interface{}{
			"event_type":     "bot_message_sent",
			"interaction_id": msg.InteractionID,
			"conversation_id": msg.ConversationID,
			"message_id":     msg.MessageID,
			"seq":            msg.Seq,
			"latency_ms":     time.Since(s.metrics.LastSendTime).Milliseconds(),
			"payload_size":   len(msg.Text) + len(msg.Buttons),
		}

		if s.analyticsCb != nil {
			s.analyticsCb(analyticsEvent)
		}
	} else {
		auditEntry["error"] = err.Error()
	}

	if s.auditCb != nil {
		s.auditCb(auditEntry)
	}

	return err
}

func (s *ConfiguredSender) GetMetrics() map[string]interface{} {
	total := s.metrics.TotalSent + s.metrics.TotalFailed
	deliveryRate := 0.0
	if total > 0 {
		deliveryRate = float64(s.metrics.TotalSent) / float64(total)
	}
	return map[string]interface{}{
		"total_sent":     s.metrics.TotalSent,
		"total_failed":   s.metrics.TotalFailed,
		"delivery_rate":  deliveryRate,
		"avg_latency_ms": s.metrics.AvgLatencyMS,
		"last_send":      s.metrics.LastSendTime.Format(time.RFC3339),
	}
}

Complete Working Example

The following script assembles all components into a runnable executable. It authenticates, establishes the WebSocket session, constructs a validated card-and-button payload, transmits it with sequence tracking, and exposes metrics.

package main

import (
	"context"
	"encoding/base64"
	"encoding/json"
	"fmt"
	"io"
	"log/slog"
	"net/http"
	"os"
	"strings"
	"time"
)

func main() {
	ctx := context.Background()
	envID := os.Getenv("GENESYS_ENV_ID")
	clientID := os.Getenv("GENESYS_CLIENT_ID")
	clientSecret := os.Getenv("GENESYS_CLIENT_SECRET")

	if envID == "" || clientID == "" || clientSecret == "" {
		fmt.Fprintln(os.Stderr, "Missing environment variables")
		os.Exit(1)
	}

	slog.Info("Acquiring OAuth token")
	token, err := getOAuthToken(ctx, envID, clientID, clientSecret)
	if err != nil {
		slog.Error("Token acquisition failed", "error", err)
		os.Exit(1)
	}

	slog.Info("Generating Webchat URL")
	wsURL, err := getWebchatURL(ctx, envID, token.AccessToken)
	if err != nil {
		slog.Error("Webchat URL generation failed", "error", err)
		os.Exit(1)
	}

	slog.Info("Connecting to Webchat WebSocket")
	session, err := NewWebchatSession(ctx, wsURL)
	if err != nil {
		slog.Error("WebSocket connection failed", "error", err)
		os.Exit(1)
	}

	analyticsCb := func(event map[string]interface{}) {
		data, _ := json.Marshal(event)
		slog.Info("Analytics callback triggered", "event", string(data))
	}

	auditCb := func(entry map[string]interface{}) {
		data, _ := json.Marshal(entry)
		slog.Info("Audit log recorded", "entry", string(data))
	}

	sender := NewConfiguredSender(session, analyticsCb, auditCb)

	msg := WebchatMessage{
		Type:          "message",
		Direction:     "inbound",
		InteractionID: "a1b2c3d4-e5f6-7890-abcd-ef1234567890",
		ConversationID: "b2c3d4e5-f6a7-8901-bcde-f12345678901",
		MessageID:     "c3d4e5f6-a7b8-9012-cdef-123456789012",
		Text:          "Select an action below.",
		Cards: []Card{
			{Type: "info", Title: "System Status", Description: "All services operational"},
		},
		Buttons: []Button{
			{Type: "postback", Label: "Acknowledge", Payload: "ACK", Action: "postback"},
			{Type: "submit", Label: "Escalate", Payload: "ESCALATE", Action: "url"},
		},
	}

	slog.Info("Sending bot message")
	err = sender.Send(ctx, msg)
	if err != nil {
		slog.Error("Send operation failed", "error", err)
	}

	metrics := sender.GetMetrics()
	slog.Info("Transmission metrics", "metrics", metrics)

	time.Sleep(5 * time.Second)
}

Common Errors and Debugging

Error: 401 Unauthorized on Webchat URL Generation

This occurs when the OAuth token lacks the webchat:urls:write scope or has expired. Verify your client credentials configuration in the Genesys Cloud admin console. Regenerate the token with the correct scope and ensure the token is passed in the Authorization: Bearer header.

Error: WebSocket Write Error: Broken Pipe

The Genesys Cloud server terminated the connection. This typically happens when the client exceeds the idle timeout or sends malformed frames. Implement the ping/pong keepalive routine shown in Step 1. Monitor the connected flag before every write operation.

Error: Payload Size Exceeds 10240 Byte Limit

Webchat clients truncate or reject oversized frames. The validator in Step 2 enforces this limit. Reduce card descriptions, remove unused image URLs, or split complex payloads into multiple sequential messages. Each message must have a unique messageId and incrementing seq.

Error: Schema Validation Failed: dive error

The dive validator tag iterates over slices. If a button or card struct contains invalid action types or exceeds field length constraints, transmission halts. Verify that Card.Type matches info or action, and Button.Action matches url or postback. Ensure Button.Type is postback or submit.

Error: Sequence Number Collision

Concurrent callers must share the same atomic counter. If you instantiate multiple WebchatSender instances over the same WebchatSession, sequence numbers will duplicate. Share a single session instance across all sender routines and rely on the mutex-protected write path.

Official References