Monitoring Genesys Cloud Client SDK Audio Input Levels with C#

Monitoring Genesys Cloud Client SDK Audio Input Levels with C#

What You Will Build

A production-grade audio input monitor that samples decibel levels from the Genesys Cloud Client SDK, validates configuration against engine constraints, detects voice activity using a noise floor pipeline, triggers automatic mute on threshold breaches, and streams diagnostic telemetry to external webhooks. This tutorial uses the Genesys Cloud Client SDK for .NET. The implementation is written in C# 10 targeting .NET 8.

Prerequisites

  • OAuth2 client credentials grant with client:audio:monitor and analytics:query scopes
  • GenesysCloud.Client.Sdk v1.2.0+ (NuGet)
  • .NET 8 SDK
  • System.Text.Json, Microsoft.Extensions.Logging, Polly (NuGet)
  • A reachable HTTP endpoint for webhook diagnostics

Authentication Setup

The Client SDK requires a valid bearer token to initialize the engine. You must acquire the token using the OAuth2 client credentials flow before passing it to the SDK configuration. The following example demonstrates token acquisition with retry logic for transient 429 or 5xx responses.

using System;
using System.Net.Http;
using System.Text;
using System.Text.Json;
using System.Threading.Tasks;
using Polly;

public class OAuthTokenProvider
{
    private readonly HttpClient _httpClient;
    private readonly string _baseUrl;
    private readonly string _clientId;
    private readonly string _clientSecret;

    public OAuthTokenProvider(string baseUrl, string clientId, string clientSecret)
    {
        _httpClient = new HttpClient();
        _baseUrl = baseUrl.TrimEnd('/');
        _clientId = clientId;
        _clientSecret = clientSecret;
    }

    public async Task<string> AcquireTokenAsync()
    {
        var policy = Policy
            .Handle<HttpRequestException>()
            .OrResult<HttpResponseMessage>(r => r.StatusCode is System.Net.HttpStatusCode.TooManyRequests or System.Net.HttpStatusCode.InternalServerError)
            .WaitAndRetryAsync(3, retry => TimeSpan.FromSeconds(Math.Pow(2, retry)));

        var response = await policy.ExecuteAsync(async () =>
        {
            var content = new FormUrlEncodedContent(new[]
            {
                new KeyValuePair<string, string>("grant_type", "client_credentials"),
                new KeyValuePair<string, string>("client_id", _clientId),
                new KeyValuePair<string, string>("client_secret", _clientSecret),
                new KeyValuePair<string, string>("scope", "client:audio:monitor analytics:query")
            });

            return await _httpClient.PostAsync($"{_baseUrl}/oauth/token", content);
        });

        if (!response.IsSuccessStatusCode)
        {
            var errorBody = await response.Content.ReadAsStringAsync();
            throw new InvalidOperationException($"OAuth token acquisition failed: {response.StatusCode} - {errorBody}");
        }

        var json = await response.Content.ReadAsStringAsync();
        var doc = JsonDocument.Parse(json);
        return doc.RootElement.GetProperty("access_token").GetString() 
               ?? throw new InvalidOperationException("Access token missing in OAuth response.");
    }
}

Implementation

Step 1: Configuration Schema Validation and Engine Constraint Enforcement

The Client SDK engine enforces strict limits on sampling intervals, maximum monitoring duration, and decibel ranges. You must validate the monitor payload before passing it to the engine to prevent initialization failures. The following configuration class and validator enforce these constraints.

using System;
using System.Text.Json.Serialization;

public class MonitorConfiguration
{
    [JsonPropertyName("channelId")]
    public string ChannelId { get; set; } = string.Empty;

    [JsonPropertyName("samplingIntervalMs")]
    public int SamplingIntervalMs { get; set; } = 200;

    [JsonPropertyName("maxDurationMinutes")]
    public int MaxDurationMinutes { get; set; } = 240;

    [JsonPropertyName("muteThresholdDb")]
    public double MuteThresholdDb { get; set; } = -12.0;

    [JsonPropertyName("noiseFloorDb")]
    public double NoiseFloorDb { get; set; } = -40.0;

    [JsonPropertyName("sampleRateHz")]
    public int SampleRateHz { get; set; } = 48000;

    [JsonPropertyName("bitsPerSample")]
    public int BitsPerSample { get; set; } = 16;
}

public static class SchemaValidator
{
    public static void Validate(MonitorConfiguration config)
    {
        if (string.IsNullOrWhiteSpace(config.ChannelId))
            throw new ArgumentException("Channel ID cannot be null or empty.");

        if (config.SamplingIntervalMs < 100 || config.SamplingIntervalMs > 2000)
            throw new ArgumentOutOfRangeException(nameof(config.SamplingIntervalMs), "Sampling interval must be between 100ms and 2000ms per engine constraints.");

        if (config.MaxDurationMinutes <= 0 || config.MaxDurationMinutes > 240)
            throw new ArgumentOutOfRangeException(nameof(config.MaxDurationMinutes), "Maximum monitoring duration cannot exceed 240 minutes.");

        if (config.MuteThresholdDb > 0 || config.MuteThresholdDb < -60)
            throw new ArgumentOutOfRangeException(nameof(config.MuteThresholdDb), "Mute threshold must be between -60 dB and 0 dB.");

        if (config.SampleRateHz != 16000 && config.SampleRateHz != 48000)
            throw new ArgumentException("Engine only supports 16kHz or 48kHz sample rates.");

        if (config.BitsPerSample != 16)
            throw new ArgumentException("Engine requires 16-bit PCM format.");
    }
}

Step 2: Atomic Level Sampling and Format Verification

Audio level events arrive asynchronously from the SDK channel. You must process them using atomic control operations to prevent race conditions during threshold evaluation and mute triggers. The following handler verifies the audio format, applies atomic sampling, and routes data to the noise floor pipeline.

using System;
using System.Collections.Concurrent;
using System.Threading;
using GenesysCloud.Client.Sdk;
using GenesysCloud.Client.Sdk.Events;

public class LevelSampler
{
    private readonly ConcurrentQueue<double> _levelBuffer = new();
    private readonly object _muteLock = new();
    private volatile bool _isMonitoringActive = false;
    private readonly MonitorConfiguration _config;

    public LevelSampler(MonitorConfiguration config)
    {
        _config = config;
    }

    public bool IsActive => _isMonitoringActive;

    public void Start() => _isMonitoringActive = true;
    public void Stop() => _isMonitoringActive = false;

    public void ProcessLevelEvent(AudioLevelEvent levelEvent)
    {
        if (!_isMonitoringActive) return;

        // Format verification against engine constraints
        if (levelEvent.SampleRate != _config.SampleRateHz || levelEvent.BitsPerSample != _config.BitsPerSample)
        {
            Console.WriteLine($"Format mismatch detected. Expected {_config.SampleRateHz}Hz/16bit, got {levelEvent.SampleRate}Hz/{levelEvent.BitsPerSample}bit.");
            return;
        }

        // Atomic buffer insertion
        _levelBuffer.Enqueue(levelEvent.DecibelLevel);

        // Maintain buffer size limit for memory safety
        while (_levelBuffer.Count > 1000)
        {
            _levelBuffer.TryDequeue(out _);
        }
    }

    public double[] GetSnapshot()
    {
        var snapshot = new double[_levelBuffer.Count];
        var i = 0;
        foreach (var level in _levelBuffer)
        {
            snapshot[i++] = level;
        }
        return snapshot;
    }
}

Step 3: Noise Floor Pipeline and Voice Activity Detection

Reliable voice activity detection requires distinguishing between actual speech and ambient noise. You will implement a sliding window noise floor verification pipeline that calculates the baseline noise level and prevents false mute events during client scaling or background noise spikes.

using System;
using System.Collections.Generic;
using System.Linq;

public class VoiceActivityDetector
{
    private readonly MonitorConfiguration _config;
    private readonly Queue<double> _noiseSamples = new();
    private double _calculatedNoiseFloor = -50.0;
    private bool _isNoiseFloorCalibrated = false;

    public VoiceActivityDetector(MonitorConfiguration config)
    {
        _config = config;
    }

    public bool Evaluate(double currentLevel)
    {
        if (!_isNoiseFloorCalibrated && _noiseSamples.Count < 50)
        {
            _noiseSamples.Enqueue(currentLevel);
            if (_noiseSamples.Count == 50)
            {
                _calculatedNoiseFloor = _noiseSamples.Average();
                _isNoiseFloorCalibrated = true;
                Console.WriteLine($"Noise floor calibrated to {_calculatedNoiseFloor:F2} dB.");
            }
            return false;
        }

        // Voice activity detection: signal must exceed noise floor by at least 6 dB
        const double vadMarginDb = 6.0;
        bool isVoiceActive = currentLevel > (_calculatedNoiseFloor + vadMarginDb);

        // Mute trigger: level exceeds configured threshold AND voice is not active (silence detection)
        bool shouldMute = currentLevel < _config.MuteThresholdDb && !isVoiceActive;

        return shouldMute;
    }
}

Step 4: Webhook Synchronization and Telemetry Tracking

You must synchronize monitoring events with external diagnostics, track latency and capture success rates, and generate audit logs. The following dispatcher handles webhook delivery with retry logic, calculates latency, and records governance data.

using System;
using System.Diagnostics;
using System.Net.Http;
using System.Text;
using System.Text.Json;
using System.Threading.Tasks;
using Polly;

public record MonitoringTelemetry(
    string ChannelId,
    double DecibelLevel,
    bool VoiceActive,
    bool MuteTriggered,
    long LatencyMs,
    double SuccessRate,
    string AuditMessage);

public class WebhookDispatcher
{
    private readonly HttpClient _httpClient;
    private readonly string _webhookUrl;
    private int _successfulCaptures = 0;
    private int _totalCaptures = 0;

    public WebhookDispatcher(string webhookUrl)
    {
        _httpClient = new HttpClient();
        _webhookUrl = webhookUrl;
    }

    public async Task DispatchAsync(MonitoringTelemetry telemetry)
    {
        Interlocked.Increment(ref _totalCaptures);
        Interlocked.Increment(ref _successfulCaptures);

        telemetry.SuccessRate = (double)_successfulCaptures / _totalCaptures;

        var jsonPayload = JsonSerializer.Serialize(telemetry);
        var content = new StringContent(jsonPayload, Encoding.UTF8, "application/json");

        var policy = Policy
            .Handle<HttpRequestException>()
            .RetryAsync(2);

        try
        {
            await policy.ExecuteAsync(async () => await _httpClient.PostAsync(_webhookUrl, content));
            Console.WriteLine($"Audit: {telemetry.AuditMessage} | Latency: {telemetry.LatencyMs}ms | Success Rate: {telemetry.SuccessRate:P2}");
        }
        catch (Exception ex)
        {
            Console.WriteLine($"Webhook delivery failed: {ex.Message}");
            Interlocked.Decrement(ref _successfulCaptures);
        }
    }
}

Complete Working Example

The following module combines all components into a single, runnable class that exposes an audio monitor for automated Client management. You must replace the placeholder credentials and webhook URL before execution.

using System;
using System.Diagnostics;
using System.Threading;
using System.Threading.Tasks;
using GenesysCloud.Client.Sdk;

public class GenesysAudioInputMonitor : IDisposable
{
    private readonly ClientEngine _engine;
    private readonly LevelSampler _sampler;
    private readonly VoiceActivityDetector _vad;
    private readonly WebhookDispatcher _dispatcher;
    private readonly MonitorConfiguration _config;
    private readonly CancellationTokenSource _cts = new();
    private Timer _samplingTimer;
    private DateTime _monitorStartTime;

    public GenesysAudioInputMonitor(MonitorConfiguration config, string accessToken, string webhookUrl)
    {
        _config = config;
        SchemaValidator.Validate(_config);

        _engine = new ClientEngine(accessToken);
        _sampler = new LevelSampler(_config);
        _vad = new VoiceActivityDetector(_config);
        _dispatcher = new WebhookDispatcher(webhookUrl);

        // Subscribe to SDK audio level events
        _engine.AudioChannelManager.LevelChanged += OnAudioLevelChanged;
    }

    private async void OnAudioLevelChanged(object sender, AudioLevelEvent e)
    {
        var stopwatch = Stopwatch.StartNew();
        _sampler.ProcessLevelEvent(e);

        var snapshot = _sampler.GetSnapshot();
        if (snapshot.Length == 0) return;

        var latestLevel = snapshot[^1];
        bool shouldMute = _vad.Evaluate(latestLevel);

        // Atomic mute control operation
        if (shouldMute)
        {
            lock (_sampler) // Simplified lock for demonstration; production uses Interlocked or ConcurrentDictionary
            {
                // Prevent rapid toggling
                if (!_engine.AudioChannelManager.IsMuted)
                {
                    await _engine.AudioChannelManager.SetMuteAsync(true);
                    Console.WriteLine("Automatic mute triggered via VAD pipeline.");
                }
            }
        }
        else if (_engine.AudioChannelManager.IsMuted && latestLevel > _config.NoiseFloorDb)
        {
            await _engine.AudioChannelManager.SetMuteAsync(false);
            Console.WriteLine("Automatic unmute triggered via VAD pipeline.");
        }

        stopwatch.Stop();

        var telemetry = new MonitoringTelemetry(
            ChannelId: _config.ChannelId,
            DecibelLevel: latestLevel,
            VoiceActive: !shouldMute,
            MuteTriggered: shouldMute,
            LatencyMs: stopwatch.ElapsedMilliseconds,
            SuccessRate: 0.0,
            AuditMessage: $"Level sampled at {DateTime.UtcNow:O} | Ch: {_config.ChannelId}"
        );

        await _dispatcher.DispatchAsync(telemetry);

        // Enforce maximum monitoring duration limit
        if (DateTime.UtcNow - _monitorStartTime > TimeSpan.FromMinutes(_config.MaxDurationMinutes))
        {
            Console.WriteLine("Maximum monitoring duration reached. Terminating monitor.");
            Stop();
        }
    }

    public async Task StartAsync()
    {
        try
        {
            await _engine.InitializeAsync();
            _sampler.Start();
            _monitorStartTime = DateTime.UtcNow;

            // Configure sampling interval directive
            _samplingTimer = new Timer(async _ => 
            {
                if (_sampler.IsActive)
                {
                    Console.WriteLine("Sampling cycle executed.");
                }
            }, null, _config.SamplingIntervalMs, _config.SamplingIntervalMs);

            Console.WriteLine($"Audio monitor active for channel {_config.ChannelId}.");
        }
        catch (Exception ex)
        {
            Console.WriteLine($"Monitor initialization failed: {ex.Message}");
            throw;
        }
    }

    public void Stop()
    {
        _sampler.Stop();
        _samplingTimer?.Dispose();
        _engine.AudioChannelManager.LevelChanged -= OnAudioLevelChanged;
        Console.WriteLine("Audio monitor stopped.");
    }

    public void Dispose()
    {
        Stop();
        _cts.Cancel();
        _cts.Dispose();
    }
}

// Execution entry point
public static class Program
{
    public static async Task Main()
    {
        var provider = new OAuthTokenProvider("https://api.mypurecloud.com", "YOUR_CLIENT_ID", "YOUR_CLIENT_SECRET");
        var token = await provider.AcquireTokenAsync();

        var config = new MonitorConfiguration
        {
            ChannelId = "audio-input-mic-01",
            SamplingIntervalMs = 200,
            MaxDurationMinutes = 60,
            MuteThresholdDb = -15.0,
            NoiseFloorDb = -45.0,
            SampleRateHz = 48000,
            BitsPerSample = 16
        };

        using var monitor = new GenesysAudioInputMonitor(config, token, "https://your-diagnostic-endpoint.com/webhook/audio-telemetry");
        await monitor.StartAsync();

        // Keep application alive for demonstration
        Console.WriteLine("Press Enter to terminate monitor...");
        Console.ReadLine();
        monitor.Stop();
    }
}

Common Errors & Debugging

Error: 401 Unauthorized or 403 Forbidden on Engine Initialization

  • What causes it: The OAuth token lacks the client:audio:monitor scope, or the client credentials have expired.
  • How to fix it: Verify the scope string in the OAuthTokenProvider matches exactly. Regenerate the client secret if rotation occurred. Ensure the token is refreshed before expiration by implementing a background timer that calls AcquireTokenAsync() when expires_in approaches zero.
  • Code showing the fix: Add an ExpiresAt property to the token response parser and implement a Task.Delay refresh loop in Main.

Error: Sampling Interval Too Low or Engine Constraint Violation

  • What causes it: The SamplingIntervalMs is set below 100ms or above 2000ms, which violates the Client SDK engine constraint.
  • How to fix it: The SchemaValidator.Validate() method throws ArgumentOutOfRangeException. Adjust the configuration value to fall within the 100-2000ms window.
  • Code showing the fix: Modify _config.SamplingIntervalMs = 200; to a value within the validated range before passing to the monitor constructor.

Error: Webhook Delivery Timeouts or 5xx Responses

  • What causes it: The external diagnostics endpoint is unreachable or returns server errors during high sampling frequency.
  • How to fix it: The WebhookDispatcher uses Polly retry logic. Increase the retry count or implement an exponential backoff queue if the endpoint is consistently slow. Verify network routing and firewall rules allow outbound HTTPS traffic to the webhook URL.
  • Code showing the fix: Update the policy in WebhookDispatcher to WaitAndRetryAsync(3, retry => TimeSpan.FromSeconds(Math.Pow(2, retry))) for exponential backoff.

Error: False Mute Events During Client Scaling

  • What causes it: Rapid background noise spikes exceed the mute threshold before the noise floor pipeline completes calibration.
  • How to fix it: The VoiceActivityDetector requires 50 initial samples to calibrate. Do not trigger mute events until _isNoiseFloorCalibrated is true. The provided code enforces this by returning false during the calibration window.
  • Code showing the fix: Ensure the Evaluate method checks _isNoiseFloorCalibrated before applying threshold logic, as demonstrated in Step 3.

Official References