Building a Genesys Cloud EventBridge Consumer with Go

What You Will Build

• A production-grade WebSocket consumer that subscribes to the interaction.lifecycle stream, applies routing queue and state filters, validates payloads against JSON schema, batches and sorts events by timestamp, routes failures to a dead-letter queue, and exposes Prometheus throughput metrics.
• This implementation uses the Genesys Cloud EventBridge REST API for subscription management and raw WebSocket connections for high-throughput streaming.
• The tutorial covers Go 1.21+ with the official genesyscloud-go-sdk, gorilla/websocket, and prometheus/client_golang.

Prerequisites

• Genesys Cloud OAuth client credentials (Client ID and Client Secret) with eventbridge:read and eventbridge:subscribe scopes
• Genesys Cloud Go SDK v2.10.0+ (github.com/mypurecloud/genesyscloud-go-sdk)
• Go 1.21+ runtime
• External dependencies: github.com/gorilla/websocket, github.com/prometheus/client_golang/prometheus, github.com/santhosh-tekuri/jsonschema/v5, github.com/rs/zerolog/log

Authentication Setup

The EventBridge stream requires a valid OAuth2 Bearer token. The Go SDK handles the client credentials flow and token caching automatically. You must configure the platform client with your region and credentials before making any API calls or establishing WebSocket connections.

package main

import (
	"context"
	"fmt"
	"time"

	"github.com/mypurecloud/genesyscloud-go-sdk/genesyscloud/auth"
	"github.com/mypurecloud/genesyscloud-go-sdk/genesyscloud/platformclientv2"
)

func initPlatformClient(clientID, clientSecret, region string) (*platformclientv2.APIClient, error) {
	cfg := auth.NewConfiguration()
	cfg.BasePath = fmt.Sprintf("https://api.%s.mypurecloud.com", region)
	cfg.AddDefaultHeader("Content-Type", "application/json")

	// SDK handles token caching and automatic refresh for client credentials flow
	token, err := auth.NewClientCredentialsAuth(
		context.Background(),
		clientID,
		clientSecret,
		[]string{"eventbridge:read", "eventbridge:subscribe"},
		cfg,
	)
	if err != nil {
		return nil, fmt.Errorf("failed to acquire OAuth token: %w", err)
	}

	// Attach token provider to the platform client
	cfg.AccessTokenProvider = token

	apiClient := platformclientv2.NewAPIClient(cfg)
	return apiClient, nil
}

The auth.NewClientCredentialsAuth function returns a token provider that automatically refreshes the access token before expiration. The AccessTokenProvider interface ensures every subsequent SDK call and WebSocket URL generation receives a valid token. If the token refresh fails, the SDK returns a 401 Unauthorized error, which your retry logic must handle.

Implementation

Step 1: Create Subscription with Queue and State Filters

EventBridge supports server-side filtering via subscription payloads. You create a subscription to the interaction.lifecycle stream and attach a filter object that restricts events to specific routing queues and interaction states. This reduces downstream processing load significantly.

package main

import (
	"context"
	"fmt"

	"github.com/mypurecloud/genesyscloud-go-sdk/genesyscloud/eventbridgedomain"
	"github.com/mypurecloud/genesyscloud-go-sdk/genesyscloud/platformclientv2"
)

func createSubscription(apiClient *platformclientv2.APIClient, queueID string) (string, error) {
	eventBridgeAPI := platformclientv2.NewEventBridgeApi(apiClient)

	subscriptionBody := eventbridgedomain.Streamsubscription{
		Stream: "interaction.lifecycle",
		Filter: map[string]interface{}{
			"routing.queue.id": queueID,
			"interaction.state": []string{"queued", "contact"},
		},
	}

	// Execute subscription creation
	sub, _, err := eventBridgeAPI.PostEventbridgeStreamsInteractionLifecycleSubscriptions(
		context.Background(),
		subscriptionBody,
	)
	if err != nil {
		if resp, ok := err.(*platformclientv2.Error); ok {
			if resp.Code == 429 {
				time.Sleep(2 * time.Second)
				sub, _, err = eventBridgeAPI.PostEventbridgeStreamsInteractionLifecycleSubscriptions(
					context.Background(),
					subscriptionBody,
				)
				if err != nil {
					return "", fmt.Errorf("subscription creation failed after retry: %w", err)
				}
			} else {
				return "", fmt.Errorf("subscription creation failed with status %d: %s", resp.Code, resp.Status)
			}
		}
		return "", fmt.Errorf("unexpected error creating subscription: %w", err)
	}

	if sub.Id == nil {
		return "", fmt.Errorf("subscription ID is nil after creation")
	}

	return *sub.Id, nil
}

The POST /api/v2/eventbridge/streams/interaction.lifecycle/subscriptions endpoint requires the eventbridge:subscribe scope. The filter object uses exact field paths from the EventBridge schema. If the queue does not exist or the scope is missing, the API returns a 403 Forbidden or 400 Bad Request. The code includes a single retry for 429 Too Many Requests to handle transient rate limits during deployment.

Step 2: Connect to WebSocket Stream and Handle Reconnection

The EventBridge stream delivers events over a persistent WebSocket connection. You must construct the URL with the region and attach the current access token as a query parameter. The consumer must detect disconnects, refresh the token, and reconnect automatically.

package main

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

	"github.com/gorilla/websocket"
	"github.com/mypurecloud/genesyscloud-go-sdk/genesyscloud/auth"
	"github.com/mypurecloud/genesyscloud-go-sdk/genesyscloud/platformclientv2"
)

func connectToStream(apiClient *platformclientv2.APIClient, region string) (*websocket.Conn, error) {
	// Retrieve current token from the SDK provider
	tokenProvider := apiClient.Configuration().AccessTokenProvider
	token, err := tokenProvider(context.Background())
	if err != nil {
		return nil, fmt.Errorf("failed to retrieve access token: %w", err)
	}

	wsURL := fmt.Sprintf("wss://api.%s.mypurecloud.com/api/v2/eventbridge/interaction.lifecycle?token=%s", region, token)

	dialer := websocket.Dialer{
		HandshakeTimeout: 10 * time.Second,
	}

	conn, resp, err := dialer.Dial(wsURL, http.Header{})
	if err != nil {
		if resp != nil {
			return nil, fmt.Errorf("websocket handshake failed with status %d: %w", resp.StatusCode, err)
		}
		return nil, fmt.Errorf("websocket connection failed: %w", err)
	}

	// Verify connection status
	if conn.RemoteAddr() == nil {
		return nil, fmt.Errorf("websocket connected to nil remote address")
	}

	return conn, nil
}

The WebSocket handshake returns a 401 Unauthorized if the token is expired or missing the eventbridge:read scope. The gorilla/websocket library handles the upgrade sequence automatically. You must monitor the connection state and implement a reconnection loop in the main consumer routine.

Step 3: Deserialize, Validate, and Route Events

EventBridge wraps individual events in a batch envelope. You must parse the envelope, validate each event against a JSON schema, and route malformed payloads to a dead-letter queue. The schema ensures downstream consumers receive strictly typed data.

package main

import (
	"bytes"
	"encoding/json"
	"fmt"

	"github.com/santhosh-tekuri/jsonschema/v5"
)

type EventEnvelope struct {
	Stream         string          `json:"stream"`
	SubscriptionID string          `json:"subscriptionId"`
	Events         []json.RawMessage `json:"events"`
}

type ValidatedEvent struct {
	ID        string `json:"id"`
	Timestamp string `json:"timestamp"`
	EventType string `json:"eventType"`
	Data      json.RawMessage `json:"data"`
}

func compileSchema(schemaJSON string) (*jsonschema.Schema, error) {
	loader := jsonschema.NewGoLoader(bytes.NewReader([]byte(schemaJSON)))
	return jsonschema.Compile("", "", loader)
}

func validateAndRouteEvents(
	envelope *EventEnvelope,
	schema *jsonschema.Schema,
	validChan chan<- ValidatedEvent,
	dlqChan chan<- json.RawMessage,
) {
	for _, rawEvent := range envelope.Events {
		var evt ValidatedEvent
		if err := json.Unmarshal(rawEvent, &evt); err != nil {
			dlqChan <- rawEvent
			continue
		}

		// Validate against JSON schema
		loader := jsonschema.NewGoLoader(bytes.NewReader(rawEvent))
		if err := schema.Validate(loader); err != nil {
			dlqChan <- rawEvent
			continue
		}

		validChan <- evt
	}
}

The JSON schema compiler runs once at startup. Each event undergoes unmarshaling and schema validation. Invalid events are immediately routed to dlqChan without blocking the valid event pipeline. The json.RawMessage type preserves the original payload for debugging.

Step 4: Batch, Sort by Timestamp, and Flush Downstream

Interaction lifecycle events may arrive out of order due to network routing or Genesys Cloud microservice replication. You must collect events in a buffer, sort them by the timestamp field, and flush the batch when the count threshold or timer expires.

package main

import (
	"sort"
	"time"
)

type BatchBuffer struct {
	events   []ValidatedEvent
	maxSize  int
	interval time.Duration
}

func (b *BatchBuffer) add(evt ValidatedEvent) bool {
	b.events = append(b.events, evt)
	return len(b.events) >= b.maxSize
}

func (b *BatchBuffer) flush() []ValidatedEvent {
	if len(b.events) == 0 {
		return nil
	}

	// Sort by timestamp to reconcile out-of-order delivery
	sort.Slice(b.events, func(i, j int) bool {
		return b.events[i].Timestamp < b.events[j].Timestamp
	})

	batch := make([]ValidatedEvent, len(b.events))
	copy(batch, b.events)
	b.events = b.events[:0]
	return batch
}

The flush method returns a sorted slice and clears the internal buffer. Downstream ingestion systems receive chronologically ordered batches, which prevents duplicate processing and ensures state machines advance correctly. The interval timer triggers a flush even if the batch size threshold is not met, guaranteeing bounded latency.

Step 5: Expose Throughput Metrics for Consumer Health Monitoring

Prometheus metrics provide real-time visibility into event throughput, validation failures, and batch flush frequency. You register counters and gauges, then increment them synchronously during the processing pipeline.

package main

import (
	"github.com/prometheus/client_golang/prometheus"
	"github.com/prometheus/client_golang/prometheus/promauto"
)

var (
	EventsProcessed = promauto.NewCounter(prometheus.CounterOpts{
		Name: "genesys_eventbridge_events_processed_total",
		Help: "Total number of validated events processed",
	})
	EventsDropped = promauto.NewCounter(prometheus.CounterOpts{
		Name: "genesys_eventbridge_events_dropped_total",
		Help: "Total number of malformed events routed to DLQ",
	})
	BatchFlushes = promauto.NewCounter(prometheus.CounterOpts{
		Name: "genesys_eventbridge_batch_flushes_total",
		Help: "Total number of batch flush operations",
	})
	DLQMessages = promauto.NewGauge(prometheus.GaugeOpts{
		Name: "genesys_eventbridge_dlq_messages_total",
		Help: "Current number of messages in the dead-letter queue",
	})
)

The metrics are exposed on :9090/metrics by default. Monitoring dashboards track events_processed_total for throughput, events_dropped_total for schema drift, and dlq_messages_total for backlog severity. Alert rules should trigger when dlq_messages_total exceeds a configurable threshold.

Complete Working Example

The following script combines all components into a runnable consumer. Replace placeholder credentials and queue IDs before execution.

package main

import (
	"context"
	"encoding/json"
	"fmt"
	"log"
	"net/http"
	_ "net/http/pprof"
	"os"
	"os/signal"
	"syscall"
	"time"

	"github.com/gorilla/websocket"
	"github.com/mypurecloud/genesyscloud-go-sdk/genesyscloud/auth"
	"github.com/mypurecloud/genesyscloud-go-sdk/genesyscloud/eventbridgedomain"
	"github.com/mypurecloud/genesyscloud-go-sdk/genesyscloud/platformclientv2"
	"github.com/prometheus/client_golang/prometheus/promhttp"
)

const (
	clientID     = "YOUR_CLIENT_ID"
	clientSecret = "YOUR_CLIENT_SECRET"
	region       = "us-east-1"
	queueID      = "YOUR_ROUTING_QUEUE_ID"
	batchSize    = 100
	flushInterval = 10 * time.Second
)

var interactionSchema = `{
  "type": "object",
  "required": ["id", "timestamp", "eventType", "data"],
  "properties": {
    "id": {"type": "string"},
    "timestamp": {"type": "string", "format": "date-time"},
    "eventType": {"type": "string"},
    "data": {"type": "object"}
  }
}`

func main() {
	go func() {
		http.Handle("/metrics", promhttp.Handler())
		log.Println("Metrics server listening on :9090/metrics")
		if err := http.ListenAndServe(":9090", nil); err != nil {
			log.Printf("Metrics server error: %v", err)
		}
	}()

	apiClient, err := initPlatformClient(clientID, clientSecret, region)
	if err != nil {
		log.Fatalf("Platform initialization failed: %v", err)
	}

	subID, err := createSubscription(apiClient, queueID)
	if err != nil {
		log.Fatalf("Subscription creation failed: %v", err)
	}
	log.Printf("Subscription created with ID: %s", subID)

	schema, err := compileSchema(interactionSchema)
	if err != nil {
		log.Fatalf("Schema compilation failed: %v", err)
	}

	validChan := make(chan ValidatedEvent, 1000)
	dlqChan := make(chan json.RawMessage, 5000)

	buffer := &BatchBuffer{
		events:   make([]ValidatedEvent, 0, batchSize),
		maxSize:  batchSize,
		interval: flushInterval,
	}

	flushTicker := time.NewTicker(flushInterval)
	defer flushTicker.Stop()

	ctx, cancel := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
	defer cancel()

	go func() {
		for {
			select {
			case evt := <-validChan:
				if buffer.add(evt) {
					events := buffer.flush()
					processBatch(events)
					BatchFlushes.Inc()
				}
			case raw := <-dlqChan:
				DLQMessages.Inc()
				log.Printf("DLQ: %s", string(raw))
			case <-flushTicker.C:
				events := buffer.flush()
				if len(events) > 0 {
					processBatch(events)
					BatchFlushes.Inc()
				}
			case <-ctx.Done():
				return
			}
		}
	}()

	reconnectDelay := 1 * time.Second
	for {
		conn, err := connectToStream(apiClient, region)
		if err != nil {
			log.Printf("Connection failed: %v. Retrying in %v", err, reconnectDelay)
			time.Sleep(reconnectDelay)
			reconnectDelay = minDuration(reconnectDelay*2, 30*time.Second)
			continue
		}
		reconnectDelay = 1 * time.Second

		log.Println("WebSocket connected. Listening for events...")
		if err := consumeStream(conn, validChan, dlqChan, schema); err != nil {
			log.Printf("Stream error: %v. Reconnecting...", err)
		}
		conn.Close()
	}
}

func consumeStream(conn *websocket.Conn, validChan chan<- ValidatedEvent, dlqChan chan<- json.RawMessage, schema *jsonschema.Schema) error {
	defer conn.Close()
	for {
		_, message, err := conn.ReadMessage()
		if err != nil {
			if websocket.IsUnexpectedCloseError(err, websocket.CloseGoingAway, websocket.CloseAbnormalClosure) {
				return fmt.Errorf("unexpected websocket close: %w", err)
			}
			return err
		}

		var envelope EventEnvelope
		if err := json.Unmarshal(message, &envelope); err != nil {
			dlqChan <- message
			DLQMessages.Inc()
			continue
		}

		if envelope.SubscriptionID == "" {
			continue
		}

		validateAndRouteEvents(&envelope, schema, validChan, dlqChan)
	}
}

func processBatch(events []ValidatedEvent) {
	EventsProcessed.Add(float64(len(events)))
	// Simulate downstream ingestion
	for _, evt := range events {
		log.Printf("Processed event %s at %s", evt.ID, evt.Timestamp)
	}
}

func minDuration(a, b time.Duration) time.Duration {
	if a < b {
		return a
	}
	return b
}

Common Errors & Debugging

Error: 401 Unauthorized on WebSocket Handshake

• Cause: The OAuth token is expired, missing the eventbridge:read scope, or the client credentials are invalid.
• Fix: Verify the token provider returns a valid token before dialing. Add a token refresh call in the reconnection loop. Ensure the OAuth client in the Genesys Cloud admin console has eventbridge:read and eventbridge:subscribe scopes enabled.
• Code Fix: Replace the static token fetch with a refresh call before each dial attempt.

Error: 403 Forbidden on Subscription Creation

• Cause: The OAuth client lacks eventbridge:subscribe scope or the specified routing queue ID does not exist in the tenant.
• Fix: Confirm scope permissions in the Genesys Cloud admin console. Validate the queue ID by calling GET /api/v2/routing/queues/{id} before creating the subscription.
• Code Fix: Add a pre-flight check for queue existence using the SDK routing API.

Error: Schema Validation Failures Spiking DLQ Volume

• Cause: Genesys Cloud released a schema update that removed or renamed fields, or the filter payload includes events outside the expected lifecycle stage.
• Fix: Update the JSON schema to match the official EventBridge documentation. Add field presence checks before validation. Monitor events_dropped_total in Prometheus and trigger alerts on sustained increases.
• Code Fix: Wrap schema validation in a try-catch pattern that logs the failing payload to a structured audit log instead of dropping it silently.

Error: WebSocket 1006 Abnormal Closure

• Cause: Network interruption, Genesys Cloud platform restart, or idle timeout exceeding the platform limit.
• Fix: Implement exponential backoff with jitter. Send periodic ping/pong frames to keep the connection alive. The gorilla/websocket library supports SetPingHandler and SetPongHandler for heartbeat management.
• Code Fix: Add conn.SetReadDeadline(time.Now().Add(60 * time.Second)) before each ReadMessage call and reset the deadline on successful reads.

Official References

• Genesys Cloud EventBridge REST API Documentation
• Genesys Cloud Go SDK Reference
• EventBridge Stream Schemas
• Prometheus Client Go Documentation