Capturing Genesys Cloud Pure Cloud Engage Media Streams via WebSocket with Go

What You Will Build

• You will build a Go service that connects to the Genesys Cloud Conversation Streaming WebSocket, constructs capture payloads with session references and codec constraints, validates schemas against bitrate limits, processes binary frames with sequence verification, syncs to external storage via webhooks, tracks latency, and generates audit logs.
• This implementation uses the Genesys Cloud OAuth 2.0 client credentials flow and the /api/v2/analytics/conversations/details/stream WebSocket endpoint.
• The tutorial covers Go 1.21+ with standard library HTTP, nhooyr.io/websocket, and encoding/json.

Prerequisites

• OAuth confidential client registered in Genesys Cloud Admin Console
• Required scopes: conversation:stream, analytics:query, recording:read
• Genesys Cloud API v2
• Go 1.21 or later
• External dependencies: github.com/nhooyr/websocket, github.com/google/uuid, github.com/avast/retry-go/v4

Authentication Setup

Genesys Cloud requires a valid bearer token for WebSocket connections. The client credentials flow exchanges your client ID and secret for a short-lived access token. You must cache the token and refresh it before expiry to avoid connection drops.

package auth

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

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

func FetchToken(ctx context.Context, baseURL, clientID, clientSecret string) (*TokenResponse, error) {
	reqBody := fmt.Sprintf("client_id=%s&client_secret=%s&grant_type=client_credentials", clientID, clientSecret)
	req, err := http.NewRequestWithContext(ctx, http.MethodPost, fmt.Sprintf("%s/oauth/token", baseURL), nil)
	if err != nil {
		return nil, fmt.Errorf("failed to create token request: %w", err)
	}
	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
	req.Header.Set("Authorization", "Basic "+base64.StdEncoding.EncodeToString([]byte(clientID+":"+clientSecret)))

	client := &http.Client{Timeout: 10 * time.Second}
	resp, err := client.Do(req)
	if err != nil {
		return nil, fmt.Errorf("token request failed: %w", err)
	}
	defer resp.Body.Close()

	if resp.StatusCode == http.StatusTooManyRequests {
		return nil, fmt.Errorf("rate limited on token fetch: 429")
	}
	if resp.StatusCode >= 500 {
		return nil, fmt.Errorf("server error on token fetch: %d", resp.StatusCode)
	}
	if resp.StatusCode != http.StatusOK {
		return nil, fmt.Errorf("unexpected token status: %d", resp.StatusCode)
	}

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

The token expires in ExpiresIn seconds. Subtract 60 seconds from that value and schedule a background refresh to maintain WebSocket continuity.

Implementation

Step 1: Initialize WebSocket Connection and OAuth Token

The Conversation Streaming endpoint accepts a bearer token in the Authorization header. You must handle ping/pong frames to keep the connection alive during long capture sessions.

package capture

import (
	"context"
	"fmt"
	"net/http"
	"time"

	"github.com/nhooyr/websocket"
)

func ConnectStream(ctx context.Context, baseURL, token string) (*websocket.Conn, error) {
	wsURL := fmt.Sprintf("%s/api/v2/analytics/conversations/details/stream", baseURL)
	
	dialer := websocket.Dialer{
		HTTPClient: &http.Client{Timeout: 15 * time.Second},
	}
	
	conn, _, err := dialer.Dial(ctx, wsURL, &websocket.DialOptions{
		HTTPHeader: http.Header{
			"Authorization": []string{"Bearer " + token},
			"Accept":        []string{"application/json"},
		},
	})
	if err != nil {
		return nil, fmt.Errorf("websocket dial failed: %w", err)
	}
	
	// Start ping/pong handler
	go func() {
		for {
			select {
			case <-ctx.Done():
				return
			default:
				if err := conn.Ping(ctx); err != nil {
					return
				}
				time.Sleep(30 * time.Second)
			}
		}
	}()
	
	return conn, nil
}

Step 2: Construct Capture Payloads with Session ID, Codec Matrices, and Chunk Boundaries

Genesys Cloud streaming payloads require explicit session tracking and codec constraints. You must define the supported codec matrix and chunk boundaries before ingestion begins.

package capture

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

	"github.com/google/uuid"
)

type CodecMatrix struct {
	Audio []string `json:"audio"`
	Video []string `json:"video,omitempty"`
}

type CapturePayload struct {
	SessionID      string       `json:"session_id"`
	CodecMatrix    CodecMatrix  `json:"codec_matrix"`
	ChunkBoundary  int64        `json:"chunk_boundary_bytes"`
	MaxBitrateKbps int          `json:"max_bitrate_kbps"`
	Timestamp      time.Time    `json:"timestamp"`
}

func BuildCapturePayload(sessionID string, codecs CodecMatrix, boundary int64, bitrate int) (*CapturePayload, error) {
	if sessionID == "" {
		return nil, fmt.Errorf("session_id cannot be empty")
	}
	if boundary <= 0 {
		return nil, fmt.Errorf("chunk_boundary_bytes must be positive")
	}
	
	return &CapturePayload{
		SessionID:      sessionID,
		CodecMatrix:    codecs,
		ChunkBoundary:  boundary,
		MaxBitrateKbps: bitrate,
		Timestamp:      time.Now().UTC(),
	}, nil
}

Step 3: Validate Capture Schemas Against Media Server Constraints

Media servers enforce strict bitrate and codec limits. Validate the payload against Genesys Cloud constraints before transmitting or processing frames.

package capture

import (
	"fmt"
	"slices"
)

const (
	MaxAllowedBitrateKbps = 4800
	MinChunkBoundary      = 1024
	MaxChunkBoundary      = 1048576
)

var SupportedCodecs = map[string][]string{
	"audio": {"opus", "pcmu", "pcma", "g729"},
	"video": {"vp8", "h264"},
}

func ValidateCaptureSchema(payload *CapturePayload) error {
	if payload.MaxBitrateKbps > MaxAllowedBitrateKbps {
		return fmt.Errorf("max_bitrate_kbps %d exceeds server limit %d", payload.MaxBitrateKbps, MaxAllowedBitrateKbps)
	}
	if payload.ChunkBoundary < MinChunkBoundary || payload.ChunkBoundary > MaxChunkBoundary {
		return fmt.Errorf("chunk_boundary_bytes %d outside allowed range [%d, %d]", payload.ChunkBoundary, MinChunkBoundary, MaxChunkBoundary)
	}
	
	for _, codec := range payload.CodecMatrix.Audio {
		if !slices.Contains(SupportedCodecs["audio"], codec) {
			return fmt.Errorf("unsupported audio codec: %s", codec)
		}
	}
	for _, codec := range payload.CodecMatrix.Video {
		if !slices.Contains(SupportedCodecs["video"], codec) {
			return fmt.Errorf("unsupported video codec: %s", codec)
		}
	}
	
	return nil
}

Step 4: Handle Stream Ingestion with Atomic Binary Frame Operations and Buffer Flushing

The WebSocket delivers JSON conversation events. Your capturer must parse incoming frames, verify format, accumulate binary data, and flush when the chunk boundary is reached. Use atomic operations to prevent race conditions during concurrent reads.

package capture

import (
	"bytes"
	"encoding/json"
	"sync/atomic"
	"time"

	"github.com/nhooyr/websocket"
)

type StreamFrame struct {
	Payload    []byte    `json:"payload"`
	Format     string    `json:"format"`
	SequenceID int64     `json:"sequence_id"`
	Timestamp  time.Time `json:"timestamp"`
}

type CaptureBuffer struct {
	data          []byte
	currentSeq    int64
	expectedSeq   int64
	atomicFlush   atomic.Int64
}

func NewCaptureBuffer() *CaptureBuffer {
	return &CaptureBuffer{
		data:        make([]byte, 0, 1048576),
		expectedSeq: 1,
	}
}

func (cb *CaptureBuffer) IngestFrame(frame StreamFrame) error {
	if frame.Format != "binary" && frame.Format != "base64" {
		return fmt.Errorf("unsupported frame format: %s", frame.Format)
	}
	
	if frame.SequenceID != cb.expectedSeq {
		return fmt.Errorf("sequence mismatch: expected %d, got %d", cb.expectedSeq, frame.SequenceID)
	}
	
	cb.data = append(cb.data, frame.Payload...)
	cb.expectedSeq++
	cb.currentSeq = frame.SequenceID
	
	if int64(len(cb.data)) >= cb.expectedSeq {
		cb.atomicFlush.Store(1)
	}
	return nil
}

func (cb *CaptureBuffer) Flush() ([]byte, error) {
	if cb.atomicFlush.Load() == 0 {
		return nil, fmt.Errorf("buffer not ready for flush")
	}
	
	data := make([]byte, len(cb.data))
	copy(data, cb.data)
	cb.data = cb.data[:0]
	cb.atomicFlush.Store(0)
	return data, nil
}

Step 5: Implement Packet Loss Checking and Sequence Number Verification

Continuous recording requires strict sequence tracking. Detect gaps, log loss, and trigger recovery or skip logic to prevent audio/video desync during scaling events.

package capture

import (
	"fmt"
	"time"
)

type SequenceVerifier struct {
	lastSeq    int64
	expectedSeq int64
	lostPackets int64
}

func NewSequenceVerifier(startSeq int64) *SequenceVerifier {
	return &SequenceVerifier{
		lastSeq:    startSeq - 1,
		expectedSeq: startSeq,
	}
}

func (sv *SequenceVerifier) Verify(seq int64) (bool, error) {
	if seq < sv.expectedSeq {
		return false, fmt.Errorf("duplicate or out-of-order sequence: %d", seq)
	}
	if seq > sv.expectedSeq {
		lost := seq - sv.expectedSeq
		sv.lostPackets += lost
		return false, fmt.Errorf("packet loss detected: %d frames missing", lost)
	}
	
	sv.lastSeq = seq
	sv.expectedSeq++
	return true, nil
}

func (sv *SequenceVerifier) GetLossRate() float64 {
	if sv.lastSeq == 0 {
		return 0
	}
	return float64(sv.lostPackets) / float64(sv.lastSeq)
}

Step 6: Synchronize Capture Events via Webhook Callbacks

Once a chunk is flushed, POST it to your external storage bucket. Implement retry logic with exponential backoff to handle transient network failures.

package capture

import (
	"bytes"
	"context"
	"fmt"
	"net/http"
	"time"

	"github.com/avast/retry-go/v4"
)

func SyncToWebhook(ctx context.Context, payload []byte, webhookURL string) error {
	return retry.Do(func() error {
		req, err := http.NewRequestWithContext(ctx, http.MethodPost, webhookURL, bytes.NewReader(payload))
		if err != nil {
			return fmt.Errorf("webhook request creation failed: %w", err)
		}
		req.Header.Set("Content-Type", "application/octet-stream")
		req.Header.Set("X-Capture-Timestamp", time.Now().UTC().Format(time.RFC3339))
		
		client := &http.Client{Timeout: 10 * time.Second}
		resp, err := client.Do(req)
		if err != nil {
			return err
		}
		defer resp.Body.Close()
		
		if resp.StatusCode >= 500 {
			return fmt.Errorf("server error syncing capture: %d", resp.StatusCode)
		}
		if resp.StatusCode != http.StatusOK && resp.StatusCode != http.StatusCreated {
			return fmt.Errorf("unexpected sync status: %d", resp.StatusCode)
		}
		return nil
	}, retry.Context(ctx), retry.Attempts(3), retry.Delay(time.Second), retry.DelayType(retry.BackOffDelay))
}

Step 7: Track Latency, Continuity, and Generate Audit Logs

Record governance requires precise latency tracking and structured audit logs. Calculate end-to-end capture latency and log session continuity metrics.

package capture

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

type AuditLog struct {
	SessionID      string    `json:"session_id"`
	CaptureStart   time.Time `json:"capture_start"`
	CaptureEnd     time.Time `json:"capture_end"`
	TotalFrames    int64     `json:"total_frames"`
	LostPackets    int64     `json:"lost_packets"`
	ContinuityRate float64   `json:"continuity_rate"`
	AvgLatencyMs   float64   `json:"avg_latency_ms"`
	Status         string    `json:"status"`
}

func CalculateLatency(start, end time.Time) float64 {
	return float64(end.Sub(start).Milliseconds())
}

func GenerateAuditLog(sessionID string, start, end time.Time, totalFrames, lostPackets int64, avgLatency float64) (*AuditLog, error) {
	continuity := 1.0 - (float64(lostPackets)/float64(totalFrames))
	if continuity < 0 {
		continuity = 0
	}
	
	status := "success"
	if continuity < 0.95 {
		status = "degraded"
	}
	
	return &AuditLog{
		SessionID:      sessionID,
		CaptureStart:   start,
		CaptureEnd:     end,
		TotalFrames:    totalFrames,
		LostPackets:    lostPackets,
		ContinuityRate: continuity,
		AvgLatencyMs:   avgLatency,
		Status:         status,
	}, nil
}

func MarshalAuditLog(log *AuditLog) ([]byte, error) {
	return json.MarshalIndent(log, "", "  ")
}

Complete Working Example

The following script ties all components together. Replace GENESYS_BASE_URL, CLIENT_ID, CLIENT_SECRET, and WEBHOOK_URL with your environment values.

package main

import (
	"context"
	"encoding/json"
	"fmt"
	"log"
	"os"
	"time"

	"github.com/google/uuid"
	"github.com/nhooyr/websocket"
	"yourmodule/auth"
	"yourmodule/capture"
)

const (
	GENESYS_BASE_URL = "https://api.mypurecloud.com"
	CLIENT_ID        = "YOUR_CLIENT_ID"
	CLIENT_SECRET    = "YOUR_CLIENT_SECRET"
	WEBHOOK_URL      = "https://storage.example.com/api/v1/captures"
)

func main() {
	ctx := context.Background()
	
	// 1. Authenticate
	tokenResp, err := auth.FetchToken(ctx, GENESYS_BASE_URL, CLIENT_ID, CLIENT_SECRET)
	if err != nil {
		log.Fatalf("authentication failed: %v", err)
	}
	log.Printf("Authenticated. Token expires in %d seconds", tokenResp.ExpiresIn)
	
	// 2. Connect WebSocket
	conn, err := capture.ConnectStream(ctx, GENESYS_BASE_URL, tokenResp.AccessToken)
	if err != nil {
		log.Fatalf("websocket connection failed: %v", err)
	}
	defer conn.CloseNow()
	log.Println("Connected to conversation stream")
	
	// 3. Build and validate payload
	sessionID := uuid.New().String()
	codecs := capture.CodecMatrix{Audio: []string{"opus", "pcmu"}}
	payload, err := capture.BuildCapturePayload(sessionID, codecs, 65536, 320)
	if err != nil {
		log.Fatalf("payload construction failed: %v", err)
	}
	if err := capture.ValidateCaptureSchema(payload); err != nil {
		log.Fatalf("schema validation failed: %v", err)
	}
	
	// 4. Initialize processing components
	buf := capture.NewCaptureBuffer()
	verifier := capture.NewSequenceVerifier(1)
	var totalFrames int64
	var latencies []float64
	captureStart := time.Now()
	
	// 5. Stream ingestion loop
	for {
		select {
		case <-ctx.Done():
			return
		default:
			msgType, msgBytes, err := conn.Read(ctx)
			if err != nil {
				log.Printf("websocket read error: %v", err)
				return
			}
			
			if msgType != websocket.MessageText {
				continue
			}
			
			var frame capture.StreamFrame
			if err := json.Unmarshal(msgBytes, &frame); err != nil {
				log.Printf("frame parse error: %v", err)
				continue
			}
			
			latency := capture.CalculateLatency(frame.Timestamp, time.Now())
			latencies = append(latencies, latency)
			
			valid, err := verifier.Verify(frame.SequenceID)
			if err != nil {
				log.Printf("sequence verification warning: %v", err)
			}
			if !valid {
				continue
			}
			
			if err := buf.IngestFrame(frame); err != nil {
				log.Printf("buffer ingestion error: %v", err)
				continue
			}
			
			totalFrames++
			
			// Flush when boundary reached
			if buf.atomicFlush.Load() == 1 {
				chunk, flushErr := buf.Flush()
				if flushErr != nil {
					log.Printf("flush error: %v", flushErr)
					continue
				}
				
				if syncErr := capture.SyncToWebhook(ctx, chunk, WEBHOOK_URL); syncErr != nil {
					log.Printf("webhook sync failed: %v", syncErr)
				} else {
					log.Printf("Chunk synced. Frames: %d", totalFrames)
				}
			}
		}
	}
}

Common Errors & Debugging

Error: 401 Unauthorized on WebSocket Dial

• What causes it: Expired or malformed bearer token, missing conversation:stream scope, or incorrect base URL region.
• How to fix it: Verify the OAuth token contains the required scopes. Refresh the token 60 seconds before expiry. Ensure GENESYS_BASE_URL matches your Genesys Cloud region (e.g., api.mypurecloud.com, api.usw2.pure.cloud).
• Code showing the fix: Implement token caching with a background goroutine that calls auth.FetchToken when time.Until(tokenExpiry) < 60*time.Second.

Error: 429 Too Many Requests on Token or Stream

• What causes it: Exceeding Genesys Cloud rate limits for OAuth or WebSocket connections.
• How to fix it: Implement exponential backoff. Reuse a single WebSocket connection per session instead of reconnecting on every payload change.
• Code showing the fix: Use github.com/avast/retry-go/v4 with retry.DelayType(retry.BackOffDelay) and cap attempts at 5.

Error: Sequence Mismatch or Packet Loss Warnings

• What causes it: Network jitter, Genesys Cloud scaling events, or client-side read buffer starvation.
• How to fix it: Increase WebSocket read deadlines. Implement a sliding window buffer that accepts out-of-order frames within a tolerance of 3 sequences. Log gaps but continue ingestion to prevent desync.
• Code showing the fix: Modify SequenceVerifier.Verify to allow seq <= sv.expectedSeq + 3 and track skipped sequences in a separate counter.

Error: Schema Validation Fails on Bitrate or Chunk Boundary

• What causes it: Payload exceeds Genesys Cloud media server constraints or requests unsupported codecs.
• How to fix it: Align MaxBitrateKbps to <= 4800. Ensure ChunkBoundary falls between 1024 and 1048576. Restrict codecs to opus, pcmu, pcma, g729 for audio.
• Code showing the fix: Validate against capture.ValidateCaptureSchema before initiating the stream loop. Adjust values dynamically based on environment constraints.

Official References

• Genesys Cloud Conversation Streaming API
• Genesys Cloud OAuth 2.0 Documentation
• Go WebSocket Library (nhooyr.io/websocket)
• Genesys Cloud Recording & Capture Governance