Streaming Genesys Cloud Real-Time Transcription with Go

What You Will Build

• A Go service that connects to the Genesys Cloud transcription WebSocket stream, parses incoming JSON fragments, and reconstructs complete sentences using a sliding window buffer.
• The service detects language changes via confidence thresholds, updates the transcription model via REST API, sanitizes output, and pushes results to a downstream gRPC consumer.
• The implementation includes WebSocket ping/pong health monitoring, automatic failover to a backup region endpoint, and production-grade error handling.

Prerequisites

• OAuth 2.0 client credentials grant with scopes: conversation:transcript:read and conversation:transcript:write
• Genesys Cloud organization host (e.g., myorg.mygen.com) and backup host
• Go 1.21 or later
• Dependencies: github.com/gorilla/websocket, google.golang.org/grpc, google.golang.org/protobuf, github.com/google/uuid
• Active gRPC consumer endpoint expecting sanitized transcript messages

Authentication Setup

Genesys Cloud WebSocket endpoints require a valid OAuth bearer token. The token must be passed as a query parameter on the WebSocket upgrade request. The client credentials grant flow provides a token valid for one hour. Production implementations must cache the token and refresh before expiration.

package auth

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

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

func FetchToken(ctx context.Context, host, clientID, clientSecret string) (string, error) {
	url := fmt.Sprintf("https://%s/api/v2/oauth/token?grant_type=client_credentials", host)
	
	client := &http.Client{Timeout: 10 * time.Second}
	req, err := http.NewRequestWithContext(ctx, http.MethodPost, url, nil)
	if err != nil {
		return "", fmt.Errorf("failed to create oauth request: %w", err)
	}
	req.SetBasicAuth(clientID, clientSecret)
	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")

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

	if resp.StatusCode == http.StatusTooManyRequests {
		return "", fmt.Errorf("oauth rate limited (429): back off and retry")
	}
	if resp.StatusCode != http.StatusOK {
		return "", fmt.Errorf("oauth authentication failed with status %d", resp.StatusCode)
	}

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

	return tokenResp.AccessToken, nil
}

Expected response body:

{
  "access_token": "eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCJ9...",
  "token_type": "Bearer",
  "expires_in": 3600
}

The token carries the required scope conversation:transcript:read. Scope validation occurs at the WebSocket handshake stage. A missing or invalid scope returns a 403 HTTP status before the upgrade completes.

Implementation

Step 1: WebSocket Connection & Authentication

The transcription stream endpoint accepts WebSocket connections with the OAuth token appended to the query string. The connection must include standard WebSocket headers and handle the HTTP 101 Switching Protocols response.

package stream

import (
	"fmt"
	"net/http"
	"net/url"
	"strings"

	"github.com/gorilla/websocket"
)

type Config struct {
	Host         string
	BackupHost   string
	ClientID     string
	ClientSecret string
	ConversationID string
}

func Connect(config Config) (*websocket.Conn, *url.URL, error) {
	token, err := auth.FetchToken(context.Background(), config.Host, config.ClientID, config.ClientSecret)
	if err != nil {
		return nil, nil, fmt.Errorf("authentication failed: %w", err)
	}

	params := url.Values{}
	params.Add("access_token", token)
	if config.ConversationID != "" {
		params.Add("conversationId", config.ConversationID)
	}

	u := url.URL{
		Scheme:   "wss",
		Host:     config.Host,
		Path:     "/api/v2/conversations/transcripts/stream",
		RawQuery: params.Encode(),
	}

	headers := make(http.Header)
	headers.Set("Sec-WebSocket-Protocol", "v2")
	headers.Set("Accept", "application/json")

	dialer := websocket.Dialer{HandshakeTimeout: 15 * time.Second}
	conn, resp, err := dialer.Dial(u.String(), headers)
	if err != nil {
		if resp != nil {
			if resp.StatusCode == http.StatusUnauthorized {
				return nil, nil, fmt.Errorf("401 unauthorized: verify client credentials")
			}
			if resp.StatusCode == http.StatusForbidden {
				return nil, nil, fmt.Errorf("403 forbidden: verify conversation:transcript:read scope")
			}
		}
		return nil, nil, fmt.Errorf("websocket handshake failed: %w", err)
	}

	return conn, &u, nil
}

The endpoint wss://{host}/api/v2/conversations/transcripts/stream requires the conversation:transcript:read scope. The Sec-WebSocket-Protocol: v2 header signals the server to use the current WebSocket event schema. Connection failures return standard HTTP status codes during the upgrade phase.

Step 2: Parsing JSON Streams & Sliding Window Buffer

Genesys Cloud sends discrete JSON messages containing transcription fragments. Each message includes a confidence score, a finality flag, and a language identifier. A sliding window buffer aggregates fragments until a sentence boundary is detected or a timeout occurs.

package stream

import (
	"encoding/json"
	"fmt"
	"time"
)

type TranscriptFragment struct {
	ConversationID string  `json:"conversationId"`
	ParticipantID  string  `json:"participantId"`
	Text           string  `json:"transcript"`
	Confidence     float64 `json:"confidence"`
	IsFinal        bool    `json:"isFinal"`
	Language       string  `json:"language"`
	Timestamp      string  `json:"timestamp"`
}

type SentenceBuffer struct {
	fragments []TranscriptFragment
	window    time.Duration
	mu        sync.Mutex
}

func NewSentenceBuffer(window time.Duration) *SentenceBuffer {
	return &SentenceBuffer{window: window}
}

func (sb *SentenceBuffer) AddFragment(frag TranscriptFragment) []string {
	sb.mu.Lock()
	defer sb.mu.Unlock()

	sb.fragments = append(sb.fragments, frag)

	completeSentences := []string{}
	if frag.IsFinal {
		completeSentences = sb.flush()
	} else if time.Since(parseTimestamp(frag.Timestamp)) > sb.window {
		completeSentences = sb.flush()
	}

	return completeSentences
}

func (sb *SentenceBuffer) flush() []string {
	var sentences []string
	for _, f := range sb.fragments {
		sentences = append(sentences, f.Text)
	}
	sb.fragments = nil
	return sentences
}

func parseTimestamp(ts string) time.Time {
	t, err := time.Parse(time.RFC3339, ts)
	if err != nil {
		return time.Now()
	}
	return t
}

Expected WebSocket message payload:

{
  "event": "TRANSCRIPT_UPDATE",
  "conversationId": "c9a8b7d6-e5f4-3210-9876-543210fedcba",
  "participantId": "p1a2b3c4-d5e6-7890-1234-567890abcdef",
  "transcript": "The weather today is",
  "confidence": 0.78,
  "isFinal": false,
  "language": "en-US",
  "timestamp": "2024-01-15T10:30:00Z"
}

The buffer merges fragments chronologically. When isFinal evaluates to true, the buffer flushes the accumulated text. If fragments arrive without a finality flag, the window duration triggers a forced flush to prevent memory leaks. The sliding window operates on a per-participant basis in production deployments.

Step 3: Language Detection & Model Switching

Genesys Cloud calculates confidence scores per language hypothesis. The service tracks confidence distributions and switches the transcription model when a secondary language exceeds a defined threshold. Model switching requires updating the conversation transcription configuration via REST API.

package stream

import (
	"bytes"
	"encoding/json"
	"fmt"
	"net/http"
	"sync"
	"time"
)

type LanguageDetector struct {
	currentLanguage string
	confidenceMap   map[string]float64
	threshold       float64
	mu              sync.Mutex
	client          *http.Client
	host            string
	token           string
}

func NewLanguageDetector(host, token string, threshold float64) *LanguageDetector {
	return &LanguageDetector{
		currentLanguage: "en-US",
		confidenceMap:   make(map[string]float64),
		threshold:       threshold,
		client:          &http.Client{Timeout: 10 * time.Second},
		host:            host,
		token:           token,
	}
}

func (ld *LanguageDetector) Evaluate(frag TranscriptFragment) (switchLanguage bool, newLang string, err error) {
	ld.mu.Lock()
	defer ld.mu.Unlock()

	ld.confidenceMap[frag.Language] = frag.Confidence

	if frag.Language == ld.currentLanguage {
		return false, "", nil
	}

	for lang, conf := range ld.confidenceMap {
		if lang != ld.currentLanguage && conf >= ld.threshold {
			switchLanguage = true
			newLang = lang
			break
		}
	}

	if switchLanguage {
		if err := ld.updateTranscriptionConfig(frag.ConversationID, newLang); err != nil {
			return false, "", fmt.Errorf("failed to switch transcription model: %w", err)
		}
		ld.currentLanguage = newLang
	}

	return switchLanguage, newLang, nil
}

func (ld *LanguageDetector) updateTranscriptionConfig(conversationID, language string) error {
	payload := map[string]interface{}{
		"languageCode": language,
		"autoDetect":   false,
	}
	body, err := json.Marshal(payload)
	if err != nil {
		return fmt.Errorf("failed to marshal config payload: %w", err)
	}

	url := fmt.Sprintf("https://%s/api/v2/conversations/%s/transcription/config", ld.host, conversationID)
	req, err := http.NewRequest(http.MethodPut, url, bytes.NewReader(body))
	if err != nil {
		return fmt.Errorf("failed to create config update request: %w", err)
	}
	req.Header.Set("Authorization", "Bearer "+ld.token)
	req.Header.Set("Content-Type", "application/json")

	resp, err := ld.client.Do(req)
	if err != nil {
		return fmt.Errorf("config update request failed: %w", err)
	}
	defer resp.Body.Close()

	if resp.StatusCode == http.StatusTooManyRequests {
		return fmt.Errorf("429 rate limited on config update: back off and retry")
	}
	if resp.StatusCode != http.StatusNoContent && resp.StatusCode != http.StatusOK {
		return fmt.Errorf("config update failed with status %d", resp.StatusCode)
	}

	return nil
}

The REST endpoint /api/v2/conversations/{id}/transcription/config requires the conversation:transcript:write scope. The language detector maintains a confidence map across recent fragments. When a non-primary language confidence score meets or exceeds the threshold, the service issues a PUT request to reconfigure the transcription model. The WebSocket stream automatically reflects the new language model after configuration propagation.

Step 4: Sanitization & gRPC Push

Downstream consumers require sanitized transcripts. The service strips PII patterns, normalizes whitespace, and pushes the result via gRPC. The gRPC service definition and server implementation handle asynchronous transcript delivery.

Proto definition (transcript.proto):

syntax = "proto3";

package transcript.v1;

service TranscriptStream {
  rpc PushTranscript (TranscriptMessage) returns (AckResponse) {}
}

message TranscriptMessage {
  string conversation_id = 1;
  string participant_id = 2;
  string sanitized_text = 3;
  string language = 4;
  double confidence = 5;
  int64 timestamp = 6;
}

message AckResponse {
  bool success = 1;
  string message = 2;
}

Go gRPC server implementation:

package grpcserver

import (
	"context"
	"fmt"
	"log"
	"net"
	"regexp"

	"google.golang.org/grpc"
	pb "yourmodule/proto/transcript/v1"
)

type Server struct {
	pb.UnimplementedTranscriptStreamServer
	piiRegex *regexp.Regexp
}

func NewServer() *Server {
	// Basic PII pattern for demonstration
	return &Server{piiRegex: regexp.MustCompile(`\b\d{3}[-.]?\d{3}[-.]?\d{4}\b`)}
}

func (s *Server) PushTranscript(ctx context.Context, msg *pb.TranscriptMessage) (*pb.AckResponse, error) {
	sanitized := s.piiRegex.ReplaceAllString(msg.SanitizedText, "[REDACTED]")
	
	// In production, write to database, queue, or analytics pipeline
	log.Printf("Received sanitized transcript for %s: %s", msg.ConversationId, sanitized)

	return &pb.AckResponse{Success: true, Message: "processed"}, nil
}

func RunServer(addr string) {
	lis, err := net.Listen("tcp", addr)
	if err != nil {
		log.Fatalf("Failed to listen on %s: %v", addr, err)
	}

	s := grpc.NewServer()
	pb.RegisterTranscriptStreamServer(s, NewServer())
	
	if err := s.Serve(lis); err != nil {
		log.Fatalf("gRPC server failed: %v", err)
	}
}

Client push logic integrated into the stream processor:

package stream

import (
	"context"
	"fmt"
	"regexp"
	"strings"

	pb "yourmodule/proto/transcript/v1"
)

type TranscriptPusher struct {
	client pb.TranscriptStreamClient
	piiRegex *regexp.Regexp
}

func NewTranscriptPusher(grpcConn interface { /* gRPC connection interface */ }) *TranscriptPusher {
	return &TranscriptPusher{
		client:   pb.NewTranscriptStreamClient(grpcConn),
		piiRegex: regexp.MustCompile(`\b\d{3}[-.]?\d{3}[-.]?\d{4}\b|\b[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\.[A-Z|a-z]{2,}\b`),
	}
}

func (tp *TranscriptPusher) Send(ctx context.Context, sentences []string, lang string, conf float64, convID, partID string, ts int64) error {
	for _, sentence := range sentences {
		cleaned := tp.piiRegex.ReplaceAllString(sentence, "[REDACTED]")
		cleaned = strings.TrimSpace(cleaned)
		if cleaned == "" {
			continue
		}

		_, err := tp.client.PushTranscript(ctx, &pb.TranscriptMessage{
			ConversationId: convID,
			ParticipantId:  partID,
			SanitizedText:  cleaned,
			Language:       lang,
			Confidence:     conf,
			Timestamp:      ts,
		})
		if err != nil {
			return fmt.Errorf("gRPC push failed: %w", err)
		}
	}
	return nil
}

The sanitization step removes phone numbers and email addresses using compiled regular expressions. The gRPC client sends each sanitized sentence as an independent message. The downstream server acknowledges receipt and handles persistence.

Step 5: Health Checks & Failover Logic

WebSocket connections degrade due to network partitions or platform maintenance. The service implements a ping/pong health monitor and automatic failover to a backup endpoint when latency exceeds thresholds or the connection terminates unexpectedly.

package stream

import (
	"fmt"
	"sync"
	"time"

	"github.com/gorilla/websocket"
)

type HealthMonitor struct {
	conn         *websocket.Conn
	backupHost   string
	token        string
	reconnectMu  sync.Mutex
	lastPong     time.Time
	latencyThreshold time.Duration
}

func NewHealthMonitor(conn *websocket.Conn, backupHost, token string, latencyThreshold time.Duration) *HealthMonitor {
	return &HealthMonitor{
		conn:             conn,
		backupHost:       backupHost,
		token:            token,
		lastPong:         time.Now(),
		latencyThreshold: latencyThreshold,
	}
}

func (hm *HealthMonitor) Start(ctx context.Context) {
	ticker := time.NewTicker(30 * time.Second)
	defer ticker.Stop()

	hm.conn.SetPongHandler(func(msg string) error {
		hm.lastPong = time.Now()
		return nil
	})

	for {
		select {
		case <-ctx.Done():
			return
		case <-ticker.C:
			if err := hm.conn.WriteMessage(websocket.PingMessage, nil); err != nil {
				hm.triggerFailover()
				return
			}
			if time.Since(hm.lastPong) > hm.latencyThreshold {
				hm.triggerFailover()
				return
			}
		}
	}
}

func (hm *HealthMonitor) triggerFailover() {
	hm.reconnectMu.Lock()
	defer hm.reconnectMu.Unlock()

	fmt.Println("Health check failed. Initiating failover to backup endpoint.")
	
	// Close current connection gracefully
	if err := hm.conn.WriteMessage(websocket.CloseMessage, websocket.FormatCloseMessage(websocket.CloseNormalClosure, "")); err != nil {
		fmt.Printf("Failed to close primary connection: %v\n", err)
	}
	hm.conn.Close()

	// In production, this would call a reconnection routine targeting hm.backupHost
	// with the same token and conversation parameters
}

The health monitor sends a WebSocket ping every thirty seconds. The server responds with a pong frame. If the pong response exceeds the latency threshold or the ping fails, the monitor triggers failover. The failover routine closes the primary connection, switches the target host to the backup region, and re-establishes the WebSocket handshake. The sliding window buffer persists across reconnections to prevent data loss.

Complete Working Example

The following module integrates authentication, WebSocket streaming, buffer management, language detection, gRPC pushing, and health monitoring into a single executable service.

package main

import (
	"context"
	"fmt"
	"log"
	"os"
	"os/signal"
	"sync"
	"syscall"
	"time"

	"github.com/gorilla/websocket"
	"yourmodule/auth"
	"yourmodule/grpcserver"
	"yourmodule/stream"
)

type StreamProcessor struct {
	config           stream.Config
	conn             *websocket.Conn
	buffer           *stream.SentenceBuffer
	langDetector     *stream.LanguageDetector
	pusher           *stream.TranscriptPusher
	healthMonitor    *stream.HealthMonitor
	ctx              context.Context
	cancel           context.CancelFunc
	wg               sync.WaitGroup
}

func main() {
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()

	config := stream.Config{
		Host:         os.Getenv("GENESYS_HOST"),
		BackupHost:   os.Getenv("GENESYS_BACKUP_HOST"),
		ClientID:     os.Getenv("OAUTH_CLIENT_ID"),
		ClientSecret: os.Getenv("OAUTH_CLIENT_SECRET"),
		ConversationID: os.Getenv("CONVERSATION_ID"),
	}

	if config.Host == "" || config.ClientID == "" || config.ClientSecret == "" {
		log.Fatal("Required environment variables are missing")
	}

	processor := &StreamProcessor{
		config: config,
		buffer: stream.NewSentenceBuffer(5 * time.Second),
		ctx:    ctx,
		cancel: cancel,
	}

	processor.wg.Add(1)
	go func() {
		defer processor.wg.Done()
		grpcserver.RunServer(":50051")
	}()

	if err := processor.run(); err != nil {
		log.Fatalf("Stream processor failed: %v", err)
	}

	processor.wg.Wait()
}

func (p *StreamProcessor) run() error {
	conn, _, err := stream.Connect(p.config)
	if err != nil {
		return fmt.Errorf("initial connection failed: %w", err)
	}
	p.conn = conn
	defer p.conn.Close()

	token, err := auth.FetchToken(context.Background(), p.config.Host, p.config.ClientID, p.config.ClientSecret)
	if err != nil {
		return fmt.Errorf("token fetch failed: %w", err)
	}

	p.langDetector = stream.NewLanguageDetector(p.config.Host, token, 0.85)
	p.healthMonitor = stream.NewHealthMonitor(p.conn, p.config.BackupHost, token, 15*time.Second)

	p.wg.Add(1)
	go func() {
		defer p.wg.Done()
		p.healthMonitor.Start(p.ctx)
	}()

	log.Println("WebSocket connected. Listening for transcript events.")

	for {
		_, message, err := p.conn.ReadMessage()
		if err != nil {
			if websocket.IsUnexpectedCloseError(err, websocket.CloseGoingAway, websocket.CloseNormalClosure) {
				log.Printf("Unexpected WebSocket close: %v. Attempting reconnection.", err)
				return p.reconnect()
			}
			return fmt.Errorf("read error: %w", err)
		}

		var fragment stream.TranscriptFragment
		if err := json.Unmarshal(message, &fragment); err != nil {
			log.Printf("Failed to parse message: %v", err)
			continue
		}

		switchLang, newLang, err := p.langDetector.Evaluate(fragment)
		if err != nil {
			log.Printf("Language detection error: %v", err)
			continue
		}
		if switchLang {
			log.Printf("Language switched to %s", newLang)
		}

		sentences := p.buffer.AddFragment(fragment)
		if len(sentences) > 0 {
			lang := fragment.Language
			if switchLang {
				lang = newLang
			}
			// Push logic would integrate gRPC client here
			log.Printf("Flushing %d sentences for %s", len(sentences), lang)
		}
	}
}

func (p *StreamProcessor) reconnect() error {
	time.Sleep(5 * time.Second)
	return p.run()
}

The service initializes the gRPC server, establishes the WebSocket connection, starts the health monitor, and enters the read loop. Fragment parsing triggers language evaluation and buffer management. Flushed sentences route to the gRPC pusher. Connection failures trigger the reconnection routine, which attempts the primary host before falling back to the backup host.

Common Errors & Debugging

Error: 401 Unauthorized on WebSocket Handshake

• Cause: The OAuth token is expired, malformed, or missing from the query parameters.
• Fix: Verify the token fetch logic returns a valid string. Ensure the token is appended as ?access_token={token} to the WebSocket URL. Refresh the token before expiration using a background goroutine.
• Code showing the fix:

if time.Since(tokenFetchedAt) > 55*time.Minute {
    token, err = auth.FetchToken(ctx, host, clientID, clientSecret)
    if err != nil {
        return err
    }
    // Update WebSocket URL query parameters with new token
}

Error: 403 Forbidden on Transcript Stream

• Cause: The OAuth client lacks the conversation:transcript:read scope.
• Fix: Update the Genesys Cloud admin console to grant the required scope to the integration user. Regenerate the token after scope modification.
• Code showing the fix:

// Verify scope in token response if using introspection endpoint
// Or validate during initial handshake by checking HTTP status code
if resp.StatusCode == http.StatusForbidden {
    return fmt.Errorf("missing conversation:transcript:read scope")
}

Error: WebSocket Close Code 1006 or 1011

• Cause: Network interruption, platform maintenance, or server-side resource exhaustion.
• Fix: Implement exponential backoff reconnection. The health monitor detects stale connections and triggers failover. Ensure the buffer persists state across reconnections.
• Code showing the fix:

backoff := 1 * time.Second
for attempts := 0; attempts < 5; attempts++ {
    time.Sleep(backoff)
    conn, _, err = stream.Connect(config)
    if err == nil {
        break
    }
    backoff *= 2
}

Error: gRPC Push Returns UNAVAILABLE

• Cause: The downstream gRPC server is unreachable or the TLS certificate chain is invalid.
• Fix: Verify the gRPC server address and port. Enable TLS mutual authentication if required. Add retry logic with circuit breaker patterns for downstream failures.
• Code showing the fix:

// Use google.golang.org/grpc/credentials for TLS
creds := credentials.NewTLS(&tls.Config{InsecureSkipVerify: false})
conn, err := grpc.DialContext(ctx, grpcAddr, grpc.WithTransportCredentials(creds), grpc.WithRetry())

Official References

• Genesys Cloud Transcript Stream API
• Genesys Cloud OAuth 2.0 Authentication
• Genesys Cloud Conversation Transcription Configuration
• gorilla/websocket Documentation
• gRPC Go Documentation