diff --git a/gui/proxy-tool/src/main/kotlin/net/rsprox/gui/ProxyToolGui.kt b/gui/proxy-tool/src/main/kotlin/net/rsprox/gui/ProxyToolGui.kt
index 0e23cefd..b20243ba 100644
--- a/gui/proxy-tool/src/main/kotlin/net/rsprox/gui/ProxyToolGui.kt
+++ b/gui/proxy-tool/src/main/kotlin/net/rsprox/gui/ProxyToolGui.kt
@@ -6,13 +6,26 @@ import javax.swing.SwingUtilities
 import javax.swing.UIManager
 
 public fun main(args: Array<String>) {
+    val rspsJavConfigUrl = System.getenv("RSPS_JAVCONFIG_URL")
+    val rspsModulus = System.getenv("RSPS_RSA")
+
+    when {
+        rspsModulus == null && rspsJavConfigUrl != null -> throw IllegalArgumentException(
+            "Missing ENV variable: RSPS_RSA",
+        )
+
+        rspsModulus != null && rspsJavConfigUrl == null -> throw IllegalArgumentException(
+            "Missing ENV variable: RSPS_JAVCONFIG_URL",
+        )
+    }
+
     if (args.isNotEmpty()) {
         System.setProperty("net.rsprox.gui.args", args.joinToString("|"))
     }
     Locale.setDefault(Locale.US)
     SplashScreen.init()
     SplashScreen.stage(0.0, "Preparing", "Setting up environment")
-    App.service.start { percentage, actionText, subActionText, progressText ->
+    App.service.start(rspsJavConfigUrl, rspsModulus) { percentage, actionText, subActionText, progressText ->
         SplashScreen.stage(percentage, actionText, subActionText, progressText)
     }
     SplashScreen.stop()
diff --git a/proxy/src/main/kotlin/net/rsprox/proxy/ProxyService.kt b/proxy/src/main/kotlin/net/rsprox/proxy/ProxyService.kt
index d6e6afcd..4123b4c8 100644
--- a/proxy/src/main/kotlin/net/rsprox/proxy/ProxyService.kt
+++ b/proxy/src/main/kotlin/net/rsprox/proxy/ProxyService.kt
@@ -92,8 +92,14 @@ public class ProxyService(
     private val connections: ProxyConnectionContainer = ProxyConnectionContainer()
     private lateinit var credentials: BinaryCredentialsStore
     private val gamePackProvider: GamePackProvider = GamePackProvider()
+    private var rspsModulus: String? = null
 
-    public fun start(progressCallback: ProgressCallback) {
+    public fun start(
+        rspsJavConfigUrl: String?,
+        rspsModulus: String?,
+        progressCallback: ProgressCallback,
+    ) {
+        this.rspsModulus = rspsModulus
         logger.info { "Starting proxy service" }
         progressCallback.update(0.05, "Proxy", "Creating directories")
         createConfigurationDirectories(CONFIGURATION_PATH)
@@ -121,7 +127,7 @@ public class ProxyService(
         this.availablePort = properties.getProperty(PROXY_PORT_MIN)
         this.bootstrapFactory = BootstrapFactory(allocator, properties)
         progressCallback.update(0.35, "Proxy", "Loading jav config")
-        val javConfig = loadJavConfig()
+        val javConfig = loadJavConfig(rspsJavConfigUrl)
         progressCallback.update(0.40, "Proxy", "Loading world list")
         this.worldListProvider = loadWorldListProvider(javConfig.getWorldListUrl())
         progressCallback.update(0.50, "Proxy", "Replacing codebase")
@@ -466,7 +472,7 @@ public class ProxyService(
                 ClientType.Native,
                 os,
                 port,
-                BigInteger(result.oldModulus, 16),
+                BigInteger(rspsModulus ?: result.oldModulus, 16),
             ),
         )
         ClientTypeDictionary[port] = "Native (${os.shortName})"
@@ -524,7 +530,7 @@ public class ProxyService(
                     ClientType.RuneLite,
                     operatingSystem,
                     port,
-                    BigInteger(oldModulus, 16),
+                    BigInteger(rspsModulus ?: oldModulus, 16),
                 ),
             )
             socket.close()
@@ -688,6 +694,15 @@ public class ProxyService(
         }
     }
 
+    private fun loadJavConfig(customUrl: String?): JavConfig {
+        val url = customUrl ?: "http://oldschool.runescape.com/jav_config.ws"
+        return runCatching("Failed to load jav_config.ws from $url") {
+            val config = JavConfig(URL(url))
+            logger.debug { "Jav config loaded from $url" }
+            config
+        }
+    }
+
     private fun loadWorldListProvider(url: String): WorldListProvider {
         return runCatching("Failed to instantiate world list provider") {
             val provider =
@@ -790,15 +805,6 @@ public class ProxyService(
         private val logger = InlineLogger()
         private val PROPERTIES_FILE = CONFIGURATION_PATH.resolve("proxy.properties")
 
-        private fun loadJavConfig(): JavConfig {
-            val url = "http://oldschool.runescape.com/jav_config.ws"
-            return runCatching("Failed to load jav_config.ws from $url") {
-                val config = JavConfig(URL(url))
-                logger.debug { "Jav config loaded from $url" }
-                config
-            }
-        }
-
         private inline fun <T> runCatching(
             errorMessage: String,
             block: () -> T,
diff --git a/proxy/src/main/kotlin/net/rsprox/proxy/binary/BinaryBlob.kt b/proxy/src/main/kotlin/net/rsprox/proxy/binary/BinaryBlob.kt
index 6bd4b1f2..a5c05022 100644
--- a/proxy/src/main/kotlin/net/rsprox/proxy/binary/BinaryBlob.kt
+++ b/proxy/src/main/kotlin/net/rsprox/proxy/binary/BinaryBlob.kt
@@ -188,10 +188,10 @@ public data class BinaryBlob(
                     header.revision,
                     header.js5MasterIndex,
                 )
-            val world = header.worldId
+
             val info =
                 LiveConnectionInfo(
-                    "oldschool${world - 300}.runescape.com",
+                    header.worldHost,
                     PORT,
                     header.revision,
                     key,