diff --git a/BTLib/build.gradle b/BTLib/build.gradle
index 4e610808..b057ceca 100644
--- a/BTLib/build.gradle
+++ b/BTLib/build.gradle
@@ -64,4 +64,6 @@ dependencies {
 
 	api libs.coroutines.core
 	api libs.coroutines.android
+
+	api libs.datastore.preferences
 }
diff --git a/BTLib/src/main/java/com/offsetnull/bt/service/ConnectionCallback.java b/BTLib/src/main/java/com/offsetnull/bt/service/ConnectionCallback.java
deleted file mode 100644
index 91d88470..00000000
--- a/BTLib/src/main/java/com/offsetnull/bt/service/ConnectionCallback.java
+++ /dev/null
@@ -1,88 +0,0 @@
-package com.offsetnull.bt.service;
-
-public interface ConnectionCallback {
-    boolean isWindowShowing();
-
-    void dataIncoming(byte[] seq);
-
-    void processedDataIncoming(CharSequence seq);
-
-    void htmlDataIncoming(String html);
-
-    void rawDataIncoming(byte[] raw);
-
-    void rawBufferIncoming(byte[] incoming);
-
-    void loadSettings();
-
-    void displayXMLError(String error);
-
-    void displaySaveError(String error);
-
-    void displayPluginSaveError(String plugin, String error);
-
-    void executeColorDebug(int arg);
-
-    void invokeDirtyExit();
-
-    void showMessage(String message, boolean longtime);
-
-    void showDialog(String message);
-
-    void doVisualBell();
-
-    void setScreenMode(boolean fullscreen);
-
-    void showKeyBoard(
-            String txt, boolean popup, boolean add, boolean flush, boolean clear, boolean close);
-
-    void doDisconnectNotice(String display);
-
-    void doLineBreak(int i);
-
-    void reloadButtons(String setName);
-
-    void clearAllButtons();
-
-    void updateMaxVitals(int hp, int mana, int moves);
-
-    void updateVitals(int hp, int mana, int moves);
-
-    void updateEnemy(int hp);
-
-    void updateVitals2(int hp, int mp, int maxhp, int maxmana, int enemy);
-
-    void luaOmg(int stateIndex);
-
-    void updateTriggerDebugString(String str);
-
-    int getPort();
-
-    String getHost();
-
-    String getDisplay();
-
-    void switchTo(String connection);
-
-    void reloadBuffer();
-
-    void loadWindowSettings();
-
-    void markWindowsDirty();
-
-    void markSettingsDirty();
-
-    void setKeepLast(boolean keep);
-
-    void setOrientation(int orientation);
-
-    void setKeepScreenOn(boolean value);
-
-    void setUseFullscreenEditor(boolean value);
-
-    void setUseSuggestions(boolean value);
-
-    void setCompatibilityMode(boolean value);
-
-    void setRegexWarning(boolean value);
-}
diff --git a/BTLib/src/main/java/com/offsetnull/bt/service/ConnectionPluginCallback.java b/BTLib/src/main/java/com/offsetnull/bt/service/ConnectionPluginCallback.java
deleted file mode 100644
index f602c9c0..00000000
--- a/BTLib/src/main/java/com/offsetnull/bt/service/ConnectionPluginCallback.java
+++ /dev/null
@@ -1,105 +0,0 @@
-/*
- * Copyright (C) Dan Block 2013
- */
-package com.offsetnull.bt.service;
-
-import android.content.Context;
-
-/** Callback interface for plugins to interact with their parent Connection. */
-public interface ConnectionPluginCallback {
-    /** Sets the plugin system dirty bit. */
-    void setTriggersDirty();
-
-    /**
-     * Finds a window by name.
-     *
-     * @param name Desired window name.
-     * @return The WindowToken associated with <b>name</b>. null if window does not exist.
-     */
-    WindowToken getWindowByName(String name);
-
-    /**
-     * Interrogates the foreground window as to its visibility state.
-     *
-     * @return The foreground window visibility state.
-     */
-    boolean isWindowShowing();
-
-    /**
-     * Attaches a window settings changed listener to the target window.
-     *
-     * @param w WindowToken to attach a listener to.
-     */
-    void attatchWindowSettingsChangedListener(WindowToken w);
-
-    /**
-     * Gets the status bar height.
-     *
-     * @return The status bar height.
-     */
-    int getStatusBarHeight();
-
-    /**
-     * Gets the title bar height.
-     *
-     * @return The title bar height.
-     */
-    int getTitleBarHeight();
-
-    /** Causes an immediate rebuild of the trigger system. */
-    void buildTriggerSystem();
-
-    /**
-     * Gets the display name for the Connection.
-     *
-     * @return The display name.
-     */
-    String getDisplayName();
-
-    /**
-     * Gets the host name for the Connection.
-     *
-     * @return The host name.
-     */
-    String getHostName();
-
-    /**
-     * Gets the port number for the Connection.
-     *
-     * @return The port number.
-     */
-    int getPort();
-
-    /**
-     * Gets the application context.
-     *
-     * @return The application context.
-     */
-    Context getContext();
-
-    /**
-     * Gets the default SettingsChangedListener used by the parent Connection.
-     *
-     * @return The SettingsChangedListener.
-     */
-    SettingsChangedListener getSettingsListener();
-
-    /**
-     * Calls a function in a target plugin.
-     *
-     * @param plugin The target plugin.
-     * @param function The target function.
-     * @param data Arugment to supply to <b>target</b>
-     */
-    void callPlugin(String plugin, String function, String data);
-
-    /**
-     * Tests weather a plugin supports a given function.
-     *
-     * @param plugin The target plugin.
-     * @param function The target function name to test.
-     * @return True if <b>plugin</b> supports <b>function</b>. False if not or <b>plugin</b> does
-     *     not exist.
-     */
-    boolean pluginSupports(String plugin, String function);
-}
diff --git a/BTLib/src/main/java/com/offsetnull/bt/service/SettingsChangedListener.java b/BTLib/src/main/java/com/offsetnull/bt/service/SettingsChangedListener.java
deleted file mode 100644
index 2f7c80e8..00000000
--- a/BTLib/src/main/java/com/offsetnull/bt/service/SettingsChangedListener.java
+++ /dev/null
@@ -1,17 +0,0 @@
-/*
- * Copyright (C) Dan Block 2013
- */
-package com.offsetnull.bt.service;
-
-/**
- * Quick little interface to give the settings system a callback to call when a setting has changed.
- */
-public interface SettingsChangedListener {
-    /**
-     * The method to call when a setting has changed.
-     *
-     * @param key The key of the setting that changed.
-     * @param value The new value of the setting.
-     */
-    void updateSetting(String key, String value);
-}
diff --git a/BTLib/src/main/java/com/offsetnull/bt/service/WindowCallback.java b/BTLib/src/main/java/com/offsetnull/bt/service/WindowCallback.java
deleted file mode 100644
index f8056188..00000000
--- a/BTLib/src/main/java/com/offsetnull/bt/service/WindowCallback.java
+++ /dev/null
@@ -1,25 +0,0 @@
-package com.offsetnull.bt.service;
-
-public interface WindowCallback {
-    boolean isWindowShowing();
-
-    void rawDataIncoming(byte[] raw);
-
-    void resetWithRawDataIncoming(byte[] raw);
-
-    void redraw();
-
-    String getName();
-
-    void shutdown();
-
-    void xcallS(String function, String str);
-
-    void xcallB(String function, byte[] raw);
-
-    void clearText();
-
-    void updateSetting(String key, String value);
-
-    void setEncoding(String value);
-}
diff --git a/BTLib/src/main/kotlin/com/offsetnull/bt/service/ConnectionCallback.kt b/BTLib/src/main/kotlin/com/offsetnull/bt/service/ConnectionCallback.kt
new file mode 100644
index 00000000..3d69319d
--- /dev/null
+++ b/BTLib/src/main/kotlin/com/offsetnull/bt/service/ConnectionCallback.kt
@@ -0,0 +1,109 @@
+package com.offsetnull.bt.service
+
+@Suppress("TooManyFunctions")
+interface ConnectionCallback {
+    fun isWindowShowing(): Boolean
+    fun dataIncoming(seq: ByteArray)
+    fun processedDataIncoming(seq: CharSequence)
+    fun htmlDataIncoming(html: String)
+    fun rawDataIncoming(raw: ByteArray)
+    fun rawBufferIncoming(incoming: ByteArray)
+    fun loadSettings()
+    fun displayXMLError(error: String)
+    fun displaySaveError(error: String)
+    fun displayPluginSaveError(plugin: String, error: String)
+    fun executeColorDebug(arg: Int)
+    fun invokeDirtyExit()
+    fun showMessage(message: String, longtime: Boolean)
+    fun showDialog(message: String)
+    fun doVisualBell()
+    fun setScreenMode(fullscreen: Boolean)
+    fun showKeyBoard(
+        txt: String,
+        popup: Boolean,
+        add: Boolean,
+        flush: Boolean,
+        clear: Boolean,
+        close: Boolean,
+    )
+    fun doDisconnectNotice(display: String)
+    fun doLineBreak(i: Int)
+    fun reloadButtons(setName: String)
+    fun clearAllButtons()
+    fun updateMaxVitals(hp: Int, mana: Int, moves: Int)
+    fun updateVitals(hp: Int, mana: Int, moves: Int)
+    fun updateEnemy(hp: Int)
+    fun updateVitals2(hp: Int, mp: Int, maxhp: Int, maxmana: Int, enemy: Int)
+    fun luaOmg(stateIndex: Int)
+    fun updateTriggerDebugString(str: String)
+    fun getPort(): Int
+    fun getHost(): String
+    fun getDisplay(): String
+    fun switchTo(connection: String)
+    fun reloadBuffer()
+    fun loadWindowSettings()
+    fun markWindowsDirty()
+    fun markSettingsDirty()
+    fun setKeepLast(keep: Boolean)
+    fun setOrientation(orientation: Int)
+    fun setKeepScreenOn(value: Boolean)
+    fun setUseFullscreenEditor(value: Boolean)
+    fun setUseSuggestions(value: Boolean)
+    fun setCompatibilityMode(value: Boolean)
+    fun setRegexWarning(value: Boolean)
+}
+
+/** Sealed event hierarchy for future Flow-based replacement of [ConnectionCallback]. */
+sealed interface ConnectionEvent {
+    data class DataIncoming(val seq: ByteArray) : ConnectionEvent
+    data class ProcessedDataIncoming(val seq: CharSequence) : ConnectionEvent
+    data class HtmlDataIncoming(val html: String) : ConnectionEvent
+    data class RawDataIncoming(val raw: ByteArray) : ConnectionEvent
+    data class RawBufferIncoming(val incoming: ByteArray) : ConnectionEvent
+    data object LoadSettings : ConnectionEvent
+    data class DisplayXMLError(val error: String) : ConnectionEvent
+    data class DisplaySaveError(val error: String) : ConnectionEvent
+    data class DisplayPluginSaveError(val plugin: String, val error: String) : ConnectionEvent
+    data class ExecuteColorDebug(val arg: Int) : ConnectionEvent
+    data object InvokeDirtyExit : ConnectionEvent
+    data class ShowMessage(val message: String, val longtime: Boolean) : ConnectionEvent
+    data class ShowDialog(val message: String) : ConnectionEvent
+    data object DoVisualBell : ConnectionEvent
+    data class SetScreenMode(val fullscreen: Boolean) : ConnectionEvent
+    data class ShowKeyBoard(
+        val txt: String,
+        val popup: Boolean,
+        val add: Boolean,
+        val flush: Boolean,
+        val clear: Boolean,
+        val close: Boolean,
+    ) : ConnectionEvent
+    data class DoDisconnectNotice(val display: String) : ConnectionEvent
+    data class DoLineBreak(val i: Int) : ConnectionEvent
+    data class ReloadButtons(val setName: String) : ConnectionEvent
+    data object ClearAllButtons : ConnectionEvent
+    data class UpdateMaxVitals(val hp: Int, val mana: Int, val moves: Int) : ConnectionEvent
+    data class UpdateVitals(val hp: Int, val mana: Int, val moves: Int) : ConnectionEvent
+    data class UpdateEnemy(val hp: Int) : ConnectionEvent
+    data class UpdateVitals2(
+        val hp: Int,
+        val mp: Int,
+        val maxhp: Int,
+        val maxmana: Int,
+        val enemy: Int,
+    ) : ConnectionEvent
+    data class LuaOmg(val stateIndex: Int) : ConnectionEvent
+    data class UpdateTriggerDebugString(val str: String) : ConnectionEvent
+    data class SwitchTo(val connection: String) : ConnectionEvent
+    data object ReloadBuffer : ConnectionEvent
+    data object LoadWindowSettings : ConnectionEvent
+    data object MarkWindowsDirty : ConnectionEvent
+    data object MarkSettingsDirty : ConnectionEvent
+    data class SetKeepLast(val keep: Boolean) : ConnectionEvent
+    data class SetOrientation(val orientation: Int) : ConnectionEvent
+    data class SetKeepScreenOn(val value: Boolean) : ConnectionEvent
+    data class SetUseFullscreenEditor(val value: Boolean) : ConnectionEvent
+    data class SetUseSuggestions(val value: Boolean) : ConnectionEvent
+    data class SetCompatibilityMode(val value: Boolean) : ConnectionEvent
+    data class SetRegexWarning(val value: Boolean) : ConnectionEvent
+}
diff --git a/BTLib/src/main/kotlin/com/offsetnull/bt/service/ConnectionPluginCallback.kt b/BTLib/src/main/kotlin/com/offsetnull/bt/service/ConnectionPluginCallback.kt
new file mode 100644
index 00000000..592a9310
--- /dev/null
+++ b/BTLib/src/main/kotlin/com/offsetnull/bt/service/ConnectionPluginCallback.kt
@@ -0,0 +1,32 @@
+package com.offsetnull.bt.service
+
+import android.content.Context
+
+@Suppress("TooManyFunctions")
+interface ConnectionPluginCallback {
+    fun setTriggersDirty()
+    fun getWindowByName(name: String): WindowToken?
+    fun isWindowShowing(): Boolean
+    fun attatchWindowSettingsChangedListener(w: WindowToken)
+    fun getStatusBarHeight(): Int
+    fun getTitleBarHeight(): Int
+    fun buildTriggerSystem()
+    fun getDisplayName(): String
+    fun getHostName(): String
+    fun getPort(): Int
+    fun getContext(): Context
+    fun getSettingsListener(): SettingsChangedListener
+    fun callPlugin(plugin: String, function: String, data: String)
+    fun pluginSupports(plugin: String, function: String): Boolean
+}
+
+/** Sealed event hierarchy for future Flow-based replacement of [ConnectionPluginCallback]. */
+sealed interface PluginEvent {
+    data object SetTriggersDirty : PluginEvent
+    data object BuildTriggerSystem : PluginEvent
+    data class CallPlugin(
+        val plugin: String,
+        val function: String,
+        val data: String,
+    ) : PluginEvent
+}
diff --git a/BTLib/src/main/kotlin/com/offsetnull/bt/service/SettingsChangedListener.kt b/BTLib/src/main/kotlin/com/offsetnull/bt/service/SettingsChangedListener.kt
new file mode 100644
index 00000000..30927783
--- /dev/null
+++ b/BTLib/src/main/kotlin/com/offsetnull/bt/service/SettingsChangedListener.kt
@@ -0,0 +1,10 @@
+package com.offsetnull.bt.service
+
+interface SettingsChangedListener {
+    fun updateSetting(key: String, value: String)
+}
+
+/** Sealed event hierarchy for future Flow-based replacement of [SettingsChangedListener]. */
+sealed interface SettingsEvent {
+    data class SettingChanged(val key: String, val value: String) : SettingsEvent
+}
diff --git a/BTLib/src/main/kotlin/com/offsetnull/bt/service/WindowCallback.kt b/BTLib/src/main/kotlin/com/offsetnull/bt/service/WindowCallback.kt
new file mode 100644
index 00000000..b7443317
--- /dev/null
+++ b/BTLib/src/main/kotlin/com/offsetnull/bt/service/WindowCallback.kt
@@ -0,0 +1,29 @@
+package com.offsetnull.bt.service
+
+@Suppress("TooManyFunctions")
+interface WindowCallback {
+    fun isWindowShowing(): Boolean
+    fun rawDataIncoming(raw: ByteArray)
+    fun resetWithRawDataIncoming(raw: ByteArray)
+    fun redraw()
+    fun getName(): String
+    fun shutdown()
+    fun xcallS(function: String, str: String)
+    fun xcallB(function: String, raw: ByteArray)
+    fun clearText()
+    fun updateSetting(key: String, value: String)
+    fun setEncoding(value: String)
+}
+
+/** Sealed event hierarchy for future Flow-based replacement of [WindowCallback]. */
+sealed interface WindowEvent {
+    data class RawDataIncoming(val raw: ByteArray) : WindowEvent
+    data class ResetWithRawDataIncoming(val raw: ByteArray) : WindowEvent
+    data object Redraw : WindowEvent
+    data object Shutdown : WindowEvent
+    data class XcallS(val function: String, val str: String) : WindowEvent
+    data class XcallB(val function: String, val raw: ByteArray) : WindowEvent
+    data object ClearText : WindowEvent
+    data class UpdateSetting(val key: String, val value: String) : WindowEvent
+    data class SetEncoding(val value: String) : WindowEvent
+}
diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index b92766e9..85fb5593 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -14,6 +14,7 @@ activityCompose = "1.12.4"
 lifecycle = "2.10.0"
 room = "2.8.4"
 coroutines = "1.10.2"
+datastore = "1.1.7"
 
 [libraries]
 appcompat = { module = "androidx.appcompat:appcompat", version.ref = "appcompat" }
@@ -33,6 +34,7 @@ room-ktx = { module = "androidx.room:room-ktx", version.ref = "room" }
 room-compiler = { module = "androidx.room:room-compiler", version.ref = "room" }
 coroutines-core = { module = "org.jetbrains.kotlinx:kotlinx-coroutines-core", version.ref = "coroutines" }
 coroutines-android = { module = "org.jetbrains.kotlinx:kotlinx-coroutines-android", version.ref = "coroutines" }
+datastore-preferences = { module = "androidx.datastore:datastore-preferences", version.ref = "datastore" }
 
 [plugins]
 android-application = { id = "com.android.application", version.ref = "agp" }