diff --git a/testing/install_script.sh b/testing/install_script.sh
index 96d1d27..56c03a8 100644
--- a/testing/install_script.sh
+++ b/testing/install_script.sh
@@ -4,26 +4,20 @@
 
 DEBIAN_VERSION=13
 
-MC_DIR_OLD=/mc_server
 MC_DIR=/mcserver
 
-if [ -d "$MC_DIR_OLD" ]; then
-    mkdir -p "$MC_DIR"
-    mv $MC_DIR_OLD/* "$MC_DIR/" 2>/dev/null || true
-fi
-
 EULA_FILE=$MC_DIR/eula.txt
 EULA_MARKER=$MC_DIR/.eula_accepted
+INSTALLED_VERSION=$MC_DIR/installed-$TARGET_VERSION
 
 SERVER_PROPERTIES=https://gitea.fithwum.tech/fithwum/minecraft/raw/branch/master/testing/server.properties
 START_FILE=https://gitea.fithwum.tech/fithwum/minecraft/raw/branch/master/testing/start.sh
+
 RUN_VANILLA=https://gitea.fithwum.tech/fithwum/minecraft/raw/branch/master/testing/run-vanilla.sh
 RUN_BUKKIT=https://gitea.fithwum.tech/fithwum/minecraft/raw/branch/master/testing/run-bukkit.sh
 RUN_FABRIC=https://gitea.fithwum.tech/fithwum/minecraft/raw/branch/master/testing/run-fabric.sh
 RUN_QUILT=https://gitea.fithwum.tech/fithwum/minecraft/raw/branch/master/testing/run-quilt.sh
 
-VERSION_CHECK=$(curl -s "https://piston-meta.mojang.com/mc/game/version_manifest_v2.json" | grep -Pom 1 '"url": "\K[^"]*'$MC_VERSION'.json')
-MC_SERVER_FILE=$(curl -s $VERSION_CHECK | jq --raw-output '.downloads.server.url')
 BUKKIT_INSTALLER_FILE=https://cdn.getbukkit.org/craftbukkit/craftbukkit-$MC_VERSION.jar
 FABRIC_SERVER_FILE=https://meta.fabricmc.net/v2/versions/loader/$MC_VERSION/$FABRIC_VERSION/$FABRIC_INSTALLER_VERSION/server/jar
 QUILT_INSTALLER_FILE=https://quiltmc.org/api/v1/download-latest-installer/java-universal
@@ -53,32 +47,6 @@ elif [ $JAVA_VERSION = "openjdk-25-jre" ]; then
 			apt-get update
 			apt-get --no-install-recommends -y install openjdk-25-jre-headless
 	fi
-# elif [ $JAVA_VERSION = "msopenjdk-21" ]; then
-#     echo "INFO ! $JAVA_VERSION Selected"
-# 	if [ dpkg -s msopenjdk-21 &> /dev/null ]
-# 		then
-# 			echo "INFO ! $JAVA_VERSION installed ... moving on."
-# 		else
-# 			echo " "
-# 			echo "WARNING ! $JAVA_VERSION not installed ... will install now."
-# 			wget https://packages.microsoft.com/config/debian/$DEBIAN_VERSION/packages-microsoft-prod.deb -O packages-microsoft-prod.deb
-# 			dpkg -i packages-microsoft-prod.deb
-# 			apt-get update && apt-get install -y msopenjdk-21
-# 			apt-get -y update && apt-get -y --fix-broken install
-# 	fi
-# elif [ $JAVA_VERSION = "msopenjdk-25" ]; then
-#     echo "INFO ! $JAVA_VERSION Selected"
-# 	if [ dpkg -s msopenjdk-25 &> /dev/null ]
-# 		then
-# 			echo "INFO ! $JAVA_VERSION installed ... moving on."
-# 		else
-# 			echo " "
-# 			echo "WARNING ! $JAVA_VERSION not installed ... will install now."
-# 			wget https://packages.microsoft.com/config/debian/$DEBIAN_VERSION/packages-microsoft-prod.deb -O packages-microsoft-prod.deb
-# 			dpkg -i packages-microsoft-prod.deb
-# 			apt-get update && apt-get install -y msopenjdk-25
-# 			apt-get -y update && apt-get -y --fix-broken install
-# 	fi
 else
 	echo "ERROR ! Java version must be set first run"
 	sleep infinity
@@ -88,27 +56,78 @@ fi
 # Check for server files and download if needed.
 if [ $MC_TYPE = "vanilla" ]; then
     echo "INFO ! Vanilla Selected"
-	if [ -e $MC_DIR/mcserver-$MC_VERSION.jar ]
-		then
-			echo " "
-			echo "INFO ! mcserver-$MC_VERSION.jar found starting now."
-		else
-			echo " "
-			echo "WARNING ! mcserver-$MC_VERSION.jar is out of date/missing ... will download now."
-			echo " "
-			echo "INFO ! Cleaning old files."
-			cd $MC_DIR
-			mkdir -pv old-server-versions/
-			rm -fr *.jar libraries defaultconfigs config mods user_jvm_args.txt run.bat
-			mv -v *.log old-server-versions/
-			wget --no-cache --show-progress --progress=bar:force:noscroll $MC_SERVER_FILE -O mcserver-$MC_VERSION.jar
-			chmod +x mcserver-$MC_VERSION.jar
-			echo " "
-			echo "WARNING ! run-$MC_TYPE-$MC_VERSION.sh is out of date/missing ... will generate now."
-			mv -v run-*.sh old-server-versions/
-			wget --no-cache --show-progress --progress=bar:force:noscroll $RUN_VANILLA -O run-$MC_TYPE-$MC_VERSION.sh
-			chmod +x run-$MC_TYPE-$MC_VERSION.sh
-			cd ..
+	# Fallback to default channel type if MC_TYPE or MC_VERSION is empty
+	: "${MC_VERSION:=latest}"
+	echo "Using server type: $MC_TYPE"
+
+	# Get the currently installed Minecraft version from the filesystem
+	CUR_VERSION=$(find "$MC_DIR" -name "installed-*" | cut -d - -f2-)
+	echo "Current local version: '${CUR_VERSION:-None}'"
+
+	# Fetch the global Minecraft version manifest cleanly
+	JSON=$(curl -s "https://piston-meta.mojang.com/mc/game/version_manifest_v2.json")
+	# Validate that we actually received valid JSON
+	if [ -z "$JSON" ] || ! echo "$JSON" | jq . >/dev/null 2>&1; then
+		echo "Error: Failed to fetch valid JSON from Mojang API"
+		exit 1
+	fi
+
+	# Resolve the target version dynamically
+	if [ ! -z "$MC_VERSION" ] && [ "$MC_VERSION" != "latest" ]; then
+		# User specified an exact version string (e.g., 1.20.1)
+		TARGET_VERSION=$(echo "$JSON" | jq -r --arg version "$MC_VERSION" '.versions[] | select(.id == $version) | .id')
+		if [ -z "$TARGET_VERSION" ]; then
+			echo "Error: Specified version '$MC_VERSION' not found in Mojang API."
+			exit 1
+		fi
+	else
+		# No version specified or "latest" chosen. Pull from the latest release
+		TARGET_VERSION=$(echo "$JSON" | jq -r '.latest.release')
+	fi
+	echo "Target version determined: '$TARGET_VERSION'"
+	# Update variable to match resolved target
+	MC_VERSION=$TARGET_VERSION
+
+	# Compare versions and only update if they do NOT match
+	if [ "$CUR_VERSION" != "$TARGET_VERSION" ]; then
+		echo "Versions differ ($CUR_VERSION vs $TARGET_VERSION). Fetching Minecraft server download URL..."
+		# Extract the target sub-manifest URL for this specific Minecraft version
+		VERSION_CHECK=$(echo "$JSON" | jq -r --arg version "$TARGET_VERSION" '.versions[] | select(.id == $version) | .url')
+		if [ "$VERSION_CHECK" == "null" ] || [ -z "$VERSION_CHECK" ]; then
+			echo "Error: Metadata URL link not found for version $TARGET_VERSION"
+			exit 1
+		fi
+		# Fetch the specific version's metadata JSON and extract the server jar link
+		MC_SERVER_FILE=$(curl -s "$VERSION_CHECK" | jq -r '.downloads.server.url')
+		if [ "$MC_SERVER_FILE" == "null" ] || [ -z "$MC_SERVER_FILE" ]; then
+			echo "Error: Server jar download URL not found for version $TARGET_VERSION"
+			exit 1
+		fi
+		echo "Ready to download: $MC_SERVER_FILE"
+		# Process Vanilla Minecraft downloads
+		echo " "
+		echo "WARNING ! Minecraft server is out of date/missing ... will download now."
+		echo "INFO ! Cleaning old files."
+		cd "$MC_DIR" || exit 1
+		mkdir -pv old-server-versions/
+		# Wipe old dependencies cleanly
+		rm -fr *.jar libraries defaultconfigs user_jvm_args.txt run.bat
+		# Safely preserve old logs
+		[ -f *.log ] && mv *.log old-server-versions/
+		# Download and fix execution modes
+		wget --no-cache --show-progress --progress=bar:force:noscroll "$MC_SERVER_FILE" -O "mcserver-$MC_VERSION.jar"
+		chmod +x "mcserver-$MC_VERSION.jar"
+		echo " "
+		echo "WARNING ! run-$MC_TYPE-$MC_VERSION.sh is out of date/missing ... will download now."
+		[ -f run-*.sh ] && mv -v run-*.sh old-server-versions/
+		wget --no-cache --show-progress --progress=bar:force:noscroll "$RUN_VANILLA" -O "run-$MC_TYPE-$MC_VERSION.sh"
+		chmod +x "run-$MC_TYPE-$MC_VERSION.sh"
+		# Drop updated marker file
+		rm -f installed-*
+		touch installed-$MC_VERSION
+		cd ..
+	else
+		echo "No update required. Local version matches target version."
 	fi
 elif [ $MC_TYPE = "bukkit" ]; then
     echo "INFO ! Bukkit Selected"