Configuring Genesys Cloud Media API Audio Codec Preferences with Java

What You Will Build

• A Java module that constructs, validates, and submits audio codec preference configurations to the Genesys Cloud Media API.
• Uses the POST /api/v2/media and PUT /api/v2/media/{mediaId} endpoints via the official Genesys Cloud Java SDK.
• Covers Java 17+ with the com.mypurecloud.api.client SDK, including fallback negotiation, constraint validation, and audit logging.

Prerequisites

• OAuth 2.0 Client Credentials grant type
• Required scopes: media:write, webhook:write
• Genesys Cloud Java SDK version 178.0.0 or higher
• Java 17 runtime environment
• External dependencies:
  • com.mypurecloud.api.client:platform-client:178.0.0
  • com.fasterxml.jackson.core:jackson-databind:2.15.2
  • org.slf4j:slf4j-api:2.0.9
  • org.slf4j:slf4j-simple:2.0.9

Authentication Setup

The Genesys Cloud Java SDK handles OAuth 2.0 client credentials flow automatically when configured with AccessTokenCache. The cache stores tokens and refreshes them transparently before expiration.

import com.mypurecloud.api.client.ApiClient;
import com.mypurecloud.api.client.Configuration;
import com.mypurecloud.api.client.auth.AccessTokenCache;

public class GenesysAuth {
    public static ApiClient initializeApiClient(String clientId, String clientSecret, String loginServer) {
        ApiClient client = new ApiClient();
        client.setBasePath(loginServer);
        
        AccessTokenCache cache = new AccessTokenCache();
        cache.setClientId(clientId);
        cache.setClientSecret(clientSecret);
        cache.setLoginServer(loginServer);
        cache.setScopes(List.of("media:write", "webhook:write"));
        
        Configuration.setDefaultApiClient(client);
        client.setAccessTokenCache(cache);
        
        return client;
    }
}

Implementation

Step 1: Payload Construction and Schema Validation

The Media API requires codec preferences to be submitted as an ordered list. You must validate the payload against a quality matrix and maximum bitrate limits before transmission. The following validator checks hardware acceleration availability, network bandwidth, and enforces a strict set directive.

import java.util.List;
import java.util.Map;

public class CodecValidator {
    private static final Map<String, Integer> MAX_BITRATE_MATRIX = Map.of(
        "opus", 510000,
        "g722", 64000,
        "pcmu", 64000,
        "pcma", 64000
    );

    private static final int MIN_BANDWIDTH_KBPS = 128;
    private static final boolean HARDWARE_ACCELERATION_AVAILABLE = true; // Replace with system check

    public record ValidationResult(boolean isValid, String reason) {}

    public ValidationResult validate(List<String> codecPreferences, int availableBandwidthKbps) {
        if (!HARDWARE_ACCELERATION_AVAILABLE) {
            return new ValidationResult(false, "Hardware acceleration unavailable for codec processing");
        }
        if (availableBandwidthKbps < MIN_BANDWIDTH_KBPS) {
            return new ValidationResult(false, String.format("Bandwidth %d kbps below minimum %d kbps", availableBandwidthKbps, MIN_BANDWIDTH_KBPS));
        }

        for (String codec : codecPreferences) {
            if (!MAX_BITRATE_MATRIX.containsKey(codec)) {
                return new ValidationResult(false, String.format("Unsupported codec: %s", codec));
            }
            int codecBitrate = MAX_BITRATE_MATRIX.get(codec);
            if (codecBitrate > availableBandwidthKbps * 1000) {
                return new ValidationResult(false, String.format("Codec %s exceeds available bandwidth", codec));
            }
        }

        return new ValidationResult(true, "Validation passed");
    }
}

Step 2: Fallback Chain Logic and Atomic PUT Operations

Codec negotiation requires a fallback chain. If the primary codec fails validation or returns a 400 error, the system iterates through the preference list. Each attempt uses an atomic PUT /api/v2/media/{mediaId} operation. The SDK handles the request serialization. You must implement exponential backoff for 429 responses and verify the response format before proceeding.

import com.mypurecloud.api.client.api.MediaApi;
import com.mypurecloud.api.client.model.CreateMediaRequest;
import com.mypurecloud.api.client.model.Media;
import com.mypurecloud.api.client.ApiException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.List;
import java.util.concurrent.TimeUnit;

public class CodecNegotiator {
    private static final Logger logger = LoggerFactory.getLogger(CodecNegotiator.class);
    private final MediaApi mediaApi;
    private final CodecValidator validator;

    public CodecNegotiator(MediaApi mediaApi, CodecValidator validator) {
        this.mediaApi = mediaApi;
        this.validator = validator;
    }

    public Media applyCodecPreferences(String mediaId, List<String> fallbackChain, int bandwidthKbps) throws ApiException, InterruptedException {
        long startTime = System.currentTimeMillis();
        boolean success = false;

        for (String codec : fallbackChain) {
            List<String> currentPreference = List.of(codec);
            var validation = validator.validate(currentPreference, bandwidthKbps);
            
            if (!validation.isValid()) {
                logger.warn("Codec {} rejected: {}", codec, validation.reason());
                continue;
            }

            try {
                CreateMediaRequest request = new CreateMediaRequest();
                request.setCodecPreferences(currentPreference);
                request.setDirection("inbound");
                request.setType("audio");

                // Atomic PUT operation
                Media response = mediaApi.putMedia(mediaId, request);
                
                if (response.getCodecPreferences() != null && response.getCodecPreferences().contains(codec)) {
                    success = true;
                    long latency = System.currentTimeMillis() - startTime;
                    logger.info("Codec {} applied successfully. Latency: {} ms", codec, latency);
                    return response;
                }
            } catch (ApiException e) {
                if (e.getCode() == 429) {
                    long delay = TimeUnit.SECONDS.toMillis(1L << (e.getRetryAfter() != null ? e.getRetryAfter() : 2));
                    logger.warn("Rate limited on codec {}. Retrying in {} ms", codec, delay);
                    Thread.sleep(delay);
                    continue;
                }
                throw e;
            }
        }

        if (!success) {
            throw new RuntimeException("All codec fallback attempts failed");
        }
        return null;
    }
}

Step 3: Webhook Synchronization, Metrics Tracking, and Audit Logging

You must synchronize codec selection events with external media servers. Register a webhook via POST /api/v2/analytics/events/webhooks. The system tracks latency and success rates, then writes audit logs for media governance.

import com.mypurecloud.api.client.api.WebhookApi;
import com.mypurecloud.api.client.model.Webhook;
import com.mypurecloud.api.client.model.WebhookRequest;
import com.mypurecloud.api.client.ApiException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.time.Instant;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.atomic.AtomicInteger;

public class CodecSelector {
    private static final Logger logger = LoggerFactory.getLogger(CodecSelector.class);
    private final WebhookApi webhookApi;
    private final List<String> auditLog = new ArrayList<>();
    private final AtomicInteger successCount = new AtomicInteger(0);
    private final AtomicInteger failureCount = new AtomicInteger(0);
    private long totalLatencyMs = 0;

    public CodecSelector(WebhookApi webhookApi) {
        this.webhookApi = webhookApi;
    }

    public void registerCodecSyncWebhook(String callbackUrl) throws ApiException {
        WebhookRequest webhookRequest = new WebhookRequest();
        webhookRequest.setName("CodecPreferenceSync");
        webhookRequest.setActive(true);
        webhookRequest.setEventType("media:codec:changed");
        webhookRequest.setWebhookType("webhook");
        webhookRequest.setCallbackUrl(callbackUrl);
        webhookRequest.setHeaders(Map.of("Content-Type", "application/json"));

        webhookApi.postAnalyticsEventsWebhooks(webhookRequest);
        logger.info("Webhook registered for codec synchronization at {}", callbackUrl);
    }

    public void logSelection(String mediaId, String codec, long latencyMs, boolean success) {
        if (success) {
            successCount.incrementAndGet();
            totalLatencyMs += latencyMs;
        } else {
            failureCount.incrementAndGet();
        }

        String auditEntry = String.format("[%s] Media: %s | Codec: %s | Success: %b | Latency: %d ms",
                Instant.now().toString(), mediaId, codec, success, latencyMs);
        auditLog.add(auditEntry);
        logger.info(auditEntry);
    }

    public void exportAuditLog() {
        logger.info("=== AUDIT LOG EXPORT ===");
        auditLog.forEach(System.out::println);
        logger.info("Total Success: {}, Total Failure: {}, Avg Latency: {} ms",
                successCount.get(),
                failureCount.get(),
                successCount.get() > 0 ? totalLatencyMs / successCount.get() : 0);
    }
}

Complete Working Example

The following module combines authentication, validation, negotiation, webhook registration, and audit logging into a single executable class. Replace the placeholder credentials and identifiers before execution.

import com.mypurecloud.api.client.ApiClient;
import com.mypurecloud.api.client.Configuration;
import com.mypurecloud.api.client.api.MediaApi;
import com.mypurecloud.api.client.api.WebhookApi;
import com.mypurecloud.api.client.model.Media;
import com.mypurecloud.api.client.ApiException;

import java.util.List;

public class GenesysCodecSelectorMain {
    public static void main(String[] args) {
        String clientId = "YOUR_CLIENT_ID";
        String clientSecret = "YOUR_CLIENT_SECRET";
        String loginServer = "https://api.mypurecloud.com";
        String mediaId = "GENERATED_MEDIA_ID_OR_CREATE_VIA_POST_FIRST";
        String externalCallbackUrl = "https://your-server.com/webhooks/codec-sync";
        int availableBandwidthKbps = 256;

        try {
            // 1. Authentication
            ApiClient client = new ApiClient();
            client.setBasePath(loginServer);
            var cache = new com.mypurecloud.api.client.auth.AccessTokenCache();
            cache.setClientId(clientId);
            cache.setClientSecret(clientSecret);
            cache.setLoginServer(loginServer);
            cache.setScopes(List.of("media:write", "webhook:write"));
            client.setAccessTokenCache(cache);
            Configuration.setDefaultApiClient(client);

            // 2. Initialize APIs
            MediaApi mediaApi = new MediaApi();
            WebhookApi webhookApi = new WebhookApi();
            CodecValidator validator = new CodecValidator();
            CodecNegotiator negotiator = new CodecNegotiator(mediaApi, validator);
            CodecSelector selector = new CodecSelector(webhookApi);

            // 3. Register webhook for external alignment
            selector.registerCodecSyncWebhook(externalCallbackUrl);

            // 4. Define fallback chain
            List<String> fallbackChain = List.of("opus", "g722", "pcmu");

            // 5. Execute negotiation
            long start = System.currentTimeMillis();
            Media result = negotiator.applyCodecPreferences(mediaId, fallbackChain, availableBandwidthKbps);
            long latency = System.currentTimeMillis() - start;

            String selectedCodec = result != null && result.getCodecPreferences() != null ? result.getCodecPreferences().get(0) : "unknown";
            selector.logSelection(mediaId, selectedCodec, latency, result != null);

            // 6. Export governance logs
            selector.exportAuditLog();

        } catch (ApiException e) {
            System.err.println("API Error: " + e.getCode() + " - " + e.getMessage());
            System.err.println("Response Body: " + e.getResponseBody());
        } catch (InterruptedException e) {
            Thread.currentThread().interrupt();
            System.err.println("Thread interrupted during negotiation");
        } catch (Exception e) {
            System.err.println("Unexpected error: " + e.getMessage());
        }
    }
}

Raw HTTP cycle equivalent for the PUT operation:

PUT /api/v2/media/{mediaId} HTTP/1.1
Host: api.mypurecloud.com
Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9...
Content-Type: application/json
Accept: application/json

{
  "type": "audio",
  "direction": "inbound",
  "codecPreferences": ["opus"]
}

HTTP/1.1 200 OK
Content-Type: application/json

{
  "id": "mediaId",
  "type": "audio",
  "direction": "inbound",
  "codecPreferences": ["opus"],
  "status": "active",
  "selfUri": "/api/v2/media/mediaId"
}

Common Errors & Debugging

Error: 400 Bad Request

• What causes it: The submitted codec name does not match Genesys Cloud supported values, or the quality matrix validation failed silently before the API call.
• How to fix it: Verify the codecPreferences array contains only opus, g722, pcmu, or pcma. Ensure the bandwidth parameter passed to CodecValidator matches actual network conditions.
• Code showing the fix:

if (!MAX_BITRATE_MATRIX.containsKey(codec)) {
    logger.error("Invalid codec reference: {}. Supported: {}", codec, MAX_BITRATE_MATRIX.keySet());
    continue;
}

Error: 403 Forbidden

• What causes it: The OAuth token lacks the media:write scope, or the client credentials are restricted to read-only operations.
• How to fix it: Regenerate the OAuth token with media:write included in the scope array. Verify the Genesys Cloud admin console grants the application media configuration permissions.
• Code showing the fix:

cache.setScopes(List.of("media:write", "webhook:write"));

Error: 429 Too Many Requests

• What causes it: The Media API enforces strict rate limits per tenant. Rapid fallback iteration triggers throttling.
• How to fix it: Implement exponential backoff. The SDK throws ApiException with a Retry-After header. Parse the header and sleep before retrying.
• Code showing the fix:

if (e.getCode() == 429) {
    long delay = e.getRetryAfter() != null ? e.getRetryAfter() * 1000 : 1000;
    Thread.sleep(delay);
    continue;
}

Error: 503 Service Unavailable

• What causes it: Genesys Cloud media servers are undergoing scaling events or maintenance. Session restart triggers may fire automatically.
• How to fix it: Implement a circuit breaker pattern. Pause requests for 30 seconds, then retry with a reduced fallback chain to lower server load.
• Code showing the fix:

if (e.getCode() == 503) {
    logger.warn("Media servers unavailable. Circuit breaker engaged for 30s");
    Thread.sleep(30000);
    // Retry with reduced chain
    fallbackChain = List.of("pcmu");
}

Official References

• Genesys Cloud Media API Documentation
• Genesys Cloud Java SDK Reference
• OAuth 2.0 Client Credentials Flow
• Webhook Configuration API