diff --git a/API/Core.cs b/API/Core.cs
deleted file mode 100644
index 5a82c7a..0000000
--- a/API/Core.cs
+++ /dev/null
@@ -1,6 +0,0 @@
-namespace ADOFAIRenderer.API;
-
-public class Core
-{
-    
-}
\ No newline at end of file
diff --git a/API/RenderSession.cs b/API/RenderSession.cs
new file mode 100644
index 0000000..95e4d91
--- /dev/null
+++ b/API/RenderSession.cs
@@ -0,0 +1,49 @@
+using System;
+using ADOFAIRenderer.Core;
+
+namespace ADOFAIRenderer.API;
+
+/// <summary>
+/// Fluent builder for configuring and starting a render session.
+/// </summary>
+public class RenderSessionBuilder
+{
+    private bool _auto = true;
+
+    public enum PatchType { Time, Screen }
+    private bool _timePatch = true;
+    private bool _screenPatch = true;
+
+    /// <summary>
+    /// Sets whether automatic rendering is enabled.
+    /// </summary>
+    /// <param name="enabled"><c>true</c> to enable automatic rendering; otherwise, <c>false</c>. Default is <c>true</c>.</param>
+    /// <returns>The current <see cref="RenderSessionBuilder"/> instance for method chaining.</returns>
+    public RenderSessionBuilder WithAuto(bool enabled = true)
+    {
+        _auto = enabled;
+        return this;
+    }
+
+    public RenderSessionBuilder WithPatch(PatchType patchType, bool enabled = true)
+    {
+        switch (patchType)
+        {
+            case PatchType.Time: _timePatch = enabled; break;
+            case PatchType.Screen: _screenPatch = enabled; break;
+            default: throw new ArgumentOutOfRangeException(nameof(patchType), patchType, null);
+        }
+        
+        return this;
+    }
+
+    /// <summary>
+    /// Applies the configured flags and initiates the render session.
+    /// </summary>
+    public void Start()
+    {
+        RenderFlags.Auto = _auto;
+        RenderFlags.TimePatch = _timePatch;
+        RenderFlags.ScreenPatch = _screenPatch;
+    }
+}
\ No newline at end of file
diff --git a/Data/PresetManager.cs b/Data/PresetManager.cs
index ea12f0f..344213a 100644
--- a/Data/PresetManager.cs
+++ b/Data/PresetManager.cs
@@ -55,102 +55,101 @@ namespace ADOFAIRenderer.Data
         public static List<RenderPreset> GetPresets()
         {
             var presets = new List<RenderPreset>();
-            string dir = GetPresetsDirectory();
-            if (!Directory.Exists(dir))
-            {
-                return presets;
-            }
+            var dir = GetPresetsDirectory();
+            
+            if (!Directory.Exists(dir)) return presets;
 
             try
             {
-                string[] files = Directory.GetFiles(dir, "*.json");
-                foreach (string file in files)
+                var files = Directory.GetFiles(dir, "*.json");
+                foreach (var file in files)
                 {
                     try
                     {
-                        string json = File.ReadAllText(file);
+                        var json = File.ReadAllText(file);
                         var jObject = JsonConvert.DeserializeObject<JObject>(json);
-                        if (jObject != null)
+                        if (jObject == null) continue;
+                        
+                        var configToken = jObject["Config"];
+                        if (configToken is JObject configObj)
                         {
-                            var configToken = jObject["Config"];
-                            if (configToken is JObject configObj)
-                            {
-                                // 1. legacy EncodingConfig -> VideoConfig
-                                if (configObj["EncodingConfig"] is JObject oldEncodingConfigObj)
-                                {
-                                    configObj["VideoConfig"] ??= oldEncodingConfigObj;
-                                    configObj.Remove("EncodingConfig");
-                                }
-
-                                // 2. legacy top-level Codec -> VideoConfig.Codec
-                                var legacyCodecToken = configObj["Codec"];
-                                if (legacyCodecToken != null && legacyCodecToken.Type != JTokenType.Null)
-                                {
-                                    if (configObj["VideoConfig"] == null || configObj["VideoConfig"]!.Type == JTokenType.Null)
-                                    {
-                                        configObj["VideoConfig"] = new JObject();
-                                    }
-                                    
-                                    var videoConfigObj = (JObject)configObj["VideoConfig"]!;
-                                    videoConfigObj["Codec"] ??= legacyCodecToken;
-                                    
-                                    configObj.Remove("Codec");
-                                }
-
-                                // 3. legacy top-level Audio properties -> AudioConfig
-                                string[] legacyAudioProps = { "RenderAudio", "AudioSampleRate", "AudioChannels", "AudioBitrate" };
-                                foreach (var prop in legacyAudioProps)
-                                {
-                                    var legacyToken = configObj[prop];
-                                    if (legacyToken != null && legacyToken.Type != JTokenType.Null)
-                                    {
-                                        if (configObj["AudioConfig"] == null || configObj["AudioConfig"]!.Type == JTokenType.Null)
-                                        {
-                                            configObj["AudioConfig"] = new JObject();
-                                        }
-
-                                        var audioConfigObj = (JObject)configObj["AudioConfig"]!;
-                                        audioConfigObj[prop] ??= legacyToken;
-                                    }
-
-                                    configObj.Remove(prop);
-                                }
-
-                                if (configObj["AudioConfig"] != null && configObj["AudioConfig"]!.Type == JTokenType.Null)
-                                {
-                                    configObj.Remove("AudioConfig");
-                                }
-
-                                // 4. legacy top-level Advanced properties -> AdvancedConfig
-                                string[] legacyAdvancedProps = { "RandomSeed", "ProcessAudio", "NonTile" };
-                                foreach (var prop in legacyAdvancedProps)
-                                {
-                                    var legacyToken = configObj[prop];
-                                    if (legacyToken != null && legacyToken.Type != JTokenType.Null)
-                                    {
-                                        if (configObj["AdvancedConfig"] == null || configObj["AdvancedConfig"]!.Type == JTokenType.Null)
-                                        {
-                                            configObj["AdvancedConfig"] = new JObject();
-                                        }
-
-                                        var advancedConfigObj = (JObject)configObj["AdvancedConfig"]!;
-                                        advancedConfigObj[prop] ??= legacyToken;
-                                    }
-
-                                    configObj.Remove(prop);
-                                }
-
-                                if (configObj["AdvancedConfig"] != null && configObj["AdvancedConfig"]!.Type == JTokenType.Null)
-                                {
-                                    configObj.Remove("AdvancedConfig");
-                                }
-                            }
+                            TryChangeKey(configObj, "DelayAfterLevelEnd", "DelayAfterEnd");
                             
-                            var preset = jObject.ToObject<RenderPreset>();
-                            if (preset != null && !string.IsNullOrEmpty(preset.Name))
+                            // 1. legacy EncodingConfig -> VideoConfig
+                            if (configObj["EncodingConfig"] is JObject oldEncodingConfigObj)
                             {
-                                presets.Add(preset);
+                                configObj["VideoConfig"] ??= oldEncodingConfigObj;
+                                configObj.Remove("EncodingConfig");
                             }
+
+                            // 2. legacy top-level Codec -> VideoConfig.Codec
+                            var legacyCodecToken = configObj["Codec"];
+                            if (legacyCodecToken != null && legacyCodecToken.Type != JTokenType.Null)
+                            {
+                                if (configObj["VideoConfig"] == null || configObj["VideoConfig"]!.Type == JTokenType.Null)
+                                {
+                                    configObj["VideoConfig"] = new JObject();
+                                }
+                                    
+                                var videoConfigObj = (JObject)configObj["VideoConfig"]!;
+                                videoConfigObj["Codec"] ??= legacyCodecToken;
+                                    
+                                configObj.Remove("Codec");
+                            }
+
+                            // 3. legacy top-level Audio properties -> AudioConfig
+                            string[] legacyAudioProps = { "RenderAudio", "AudioSampleRate", "AudioChannels", "AudioBitrate" };
+                            foreach (var prop in legacyAudioProps)
+                            {
+                                var legacyToken = configObj[prop];
+                                if (legacyToken != null && legacyToken.Type != JTokenType.Null)
+                                {
+                                    if (configObj["AudioConfig"] == null || configObj["AudioConfig"]!.Type == JTokenType.Null)
+                                    {
+                                        configObj["AudioConfig"] = new JObject();
+                                    }
+
+                                    var audioConfigObj = (JObject)configObj["AudioConfig"]!;
+                                    audioConfigObj[prop] ??= legacyToken;
+                                }
+
+                                configObj.Remove(prop);
+                            }
+
+                            if (configObj["AudioConfig"] != null && configObj["AudioConfig"]!.Type == JTokenType.Null)
+                            {
+                                configObj.Remove("AudioConfig");
+                            }
+
+                            // 4. legacy top-level Advanced properties -> AdvancedConfig
+                            string[] legacyAdvancedProps = { "RandomSeed", "ProcessAudio", "NonTile" };
+                            foreach (var prop in legacyAdvancedProps)
+                            {
+                                var legacyToken = configObj[prop];
+                                if (legacyToken != null && legacyToken.Type != JTokenType.Null)
+                                {
+                                    if (configObj["AdvancedConfig"] == null || configObj["AdvancedConfig"]!.Type == JTokenType.Null)
+                                    {
+                                        configObj["AdvancedConfig"] = new JObject();
+                                    }
+
+                                    var advancedConfigObj = (JObject)configObj["AdvancedConfig"]!;
+                                    advancedConfigObj[prop] ??= legacyToken;
+                                }
+
+                                configObj.Remove(prop);
+                            }
+
+                            if (configObj["AdvancedConfig"] != null && configObj["AdvancedConfig"]!.Type == JTokenType.Null)
+                            {
+                                configObj.Remove("AdvancedConfig");
+                            }
+                        }
+                            
+                        var preset = jObject.ToObject<RenderPreset>();
+                        if (preset != null && !string.IsNullOrEmpty(preset.Name))
+                        {
+                            presets.Add(preset);
                         }
                     }
                     catch (Exception ex)
@@ -167,6 +166,15 @@ namespace ADOFAIRenderer.Data
             return presets;
         }
 
+        private static void TryChangeKey(JObject configObj, string keyBefore, string targetKey)
+        {
+            var legacyToken = configObj[keyBefore];
+            if (legacyToken != null && legacyToken.Type != JTokenType.Null)
+                configObj[targetKey] = legacyToken;
+
+            configObj.Remove(keyBefore);
+        }
+
         public static void DeletePreset(string name)
         {
             string dir = GetPresetsDirectory();
diff --git a/Data/RenderConfig.cs b/Data/RenderConfig.cs
index a8ce42b..7181ac8 100644
--- a/Data/RenderConfig.cs
+++ b/Data/RenderConfig.cs
@@ -2,7 +2,7 @@ using ADOFAIRenderer.Util.FFmpeg;
 
 namespace ADOFAIRenderer.Data
 {
-    internal class RenderConfig
+    public class RenderConfig
     {
         public double RenderFPS { get; set; }
         public double VideoFPS { get; set; }
@@ -14,18 +14,18 @@ namespace ADOFAIRenderer.Data
         public AudioEncodingConfig AudioConfig { get; set; } = new();
         public AdvancedConfig AdvancedConfig { get; set; } = new();
 
-        public double DelayAfterLevelEnd { get; set; }
+        public double DelayAfterEnd { get; set; }
         public bool ShowJudgementText { get; set; }
     }
 
-    internal class AdvancedConfig
+    public class AdvancedConfig
     {
         public int? RandomSeed { get; set; } = null;
         public bool ProcessAudio { get; set; } = true;
         public bool NonTile { get; set; } = false;
     }
 
-    internal class VideoEncodingConfig
+    public class VideoEncodingConfig
     {
         public Codec Codec { get; set; } = Codec.H264;
         public RateControlMode RateControlMode { get; set; } = RateControlMode.CBR;
@@ -35,10 +35,10 @@ namespace ADOFAIRenderer.Data
         // ReSharper disable once InconsistentNaming
         public int QP { get; set; } = 18;
         public double KeyframeInterval { get; set; } = 2.0;
-        public bool ForceSoftwareEncoder { get; set; } = false;
+        public bool ForceSoftwareEncoder { get; set; }
     }
 
-    internal class AudioEncodingConfig
+    public class AudioEncodingConfig
     {
         private int _audioSampleRate = 44100;
         private int _audioChannels = 2;