diff --git a/common/implementation/base/src/main/java/com/dfsek/terra/registry/CliExtensibleRegistry.java b/common/implementation/base/src/main/java/com/dfsek/terra/registry/CliExtensibleRegistry.java
new file mode 100644
index 0000000000..032e11a1a9
--- /dev/null
+++ b/common/implementation/base/src/main/java/com/dfsek/terra/registry/CliExtensibleRegistry.java
@@ -0,0 +1,93 @@
+package com.dfsek.terra.registry;
+
+import com.google.errorprone.annotations.MustBeClosed;
+import org.intellij.lang.annotations.Pattern;
+import org.jspecify.annotations.Nullable;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Arrays;
+import java.util.Objects;
+import java.util.stream.Stream;
+
+
+/**
+ * A file-discoverable registry that can be extended by system properties
+ * <br>
+ * The main use-case for this is to allow for customized locations of file-system-based key entries,
+ * such as putting config packs into custom locations.
+ * <br>
+ * Two system properties are used to define the search path:
+ * <br>
+ * <code>terra.registry.{searchPathName}.searchPath</code> is a list of "parent folder" paths (like the pack directory) that
+ * will be searched for contained files.
+ * <br>
+ * <code>terra.registry.{searchPathName}.extraPath</code> is a list of files that will be directly evaluated for membership and
+ * as such will be directly treated as members of the registry.
+ * <br>
+ * These system properties are formatted like UNIX-style paths, with each path separated by a colon (':') character.
+ */
+public interface CliExtensibleRegistry {
+    /**
+     * Get a lowercase search path name for this registry that will get plugged into
+     * <br>
+     * <code>terra.registry.{searchPathName}.searchPath</code>
+     * <br>
+     * and
+     * <br>
+     * <code>terra.registry.{searchPathName}.extraPath</code>
+     */
+    @Pattern("^[a-z._]+$")
+    String getRegistryName();
+
+    /**
+     * Check if a path may be a member of this registry heuristically.
+     *
+     * @param path Path to check
+     *
+     * @return True if the path is a member of this registry.
+     */
+    boolean validatePathIsMember(Path path);
+
+    default @MustBeClosed Stream<Path> getMemberPaths(Path baseSearchPath) {
+        String basePropertyName = "terra.registry." + getRegistryName();
+
+        Stream<Path> searchPath = Stream.concat(
+            parseValidPaths(System.getProperty(basePropertyName + ".searchPath")),
+            Stream.of(baseSearchPath)
+        );
+
+        Stream<Path> extraPath = parseValidPaths(System.getProperty(basePropertyName + ".extraPath"));
+
+        return Stream.concat(
+                searchPath
+                    .filter(Files::isDirectory)
+                    .flatMap(CliExtensibleRegistry::listDirectory),
+                extraPath
+            )
+            .filter(this::validatePathIsMember);
+    }
+
+    private static Stream<Path> parseValidPaths(@Nullable String paths) {
+        return Stream.ofNullable(paths)
+            .flatMap(p -> Arrays.stream(p.split(":")))
+            .filter(v -> !v.isBlank())
+            .map(v -> {
+                try {
+                    return Path.of(v).toAbsolutePath().normalize();
+                } catch (Exception e) {
+                    return null;
+                }
+            })
+            .filter(Objects::nonNull);
+    }
+
+    private static Stream<Path> listDirectory(Path dir) {
+        try {
+            return Files.list(dir);
+        } catch(IOException e) {
+            return Stream.empty();
+        }
+    }
+}
diff --git a/common/implementation/base/src/main/java/com/dfsek/terra/registry/master/ConfigRegistry.java b/common/implementation/base/src/main/java/com/dfsek/terra/registry/master/ConfigRegistry.java
index f4b4c9dd1a..831188299b 100644
--- a/common/implementation/base/src/main/java/com/dfsek/terra/registry/master/ConfigRegistry.java
+++ b/common/implementation/base/src/main/java/com/dfsek/terra/registry/master/ConfigRegistry.java
@@ -29,13 +29,14 @@
 import com.dfsek.terra.api.config.ConfigPack;
 import com.dfsek.terra.api.util.reflection.TypeKey;
 import com.dfsek.terra.config.pack.ConfigPackImpl;
+import com.dfsek.terra.registry.CliExtensibleRegistry;
 import com.dfsek.terra.registry.OpenRegistryImpl;
 
 
 /**
  * Class to hold config packs
  */
-public class ConfigRegistry extends OpenRegistryImpl<ConfigPack> {
+public class ConfigRegistry extends OpenRegistryImpl<ConfigPack> implements CliExtensibleRegistry {
 
     public ConfigRegistry() {
         super(TypeKey.of(ConfigPack.class));
@@ -45,7 +46,7 @@ public synchronized void loadAll(Platform platform) throws IOException, PackLoad
         Path packsDirectory = platform.getDataFolder().toPath().resolve("packs");
         Files.createDirectories(packsDirectory);
         List<Exception> failedLoads = new CopyOnWriteArrayList<>();
-        try(Stream<Path> packs = Files.list(packsDirectory)) {
+        try(Stream<Path> packs = getMemberPaths(packsDirectory)) {
             packs.parallel().forEach(path -> {
                 try {
                     ConfigPack pack = new ConfigPackImpl(path, platform);
@@ -60,6 +61,17 @@ public synchronized void loadAll(Platform platform) throws IOException, PackLoad
         }
     }
 
+    @Override
+    public String getRegistryName() {
+        return "config";
+    }
+
+    @Override
+    public boolean validatePathIsMember(Path path) {
+        var file = path.toFile();
+        return file.isDirectory() || file.getName().endsWith(".zip");
+    }
+
     public static class PackLoadFailuresException extends Exception {
         @Serial
         private static final long serialVersionUID = 538998844645186306L;
diff --git a/common/implementation/base/src/main/java/com/dfsek/terra/registry/master/MetaConfigRegistry.java b/common/implementation/base/src/main/java/com/dfsek/terra/registry/master/MetaConfigRegistry.java
index 05539475e5..9adeb0c711 100644
--- a/common/implementation/base/src/main/java/com/dfsek/terra/registry/master/MetaConfigRegistry.java
+++ b/common/implementation/base/src/main/java/com/dfsek/terra/registry/master/MetaConfigRegistry.java
@@ -28,6 +28,7 @@
 import com.dfsek.terra.api.config.MetaPack;
 import com.dfsek.terra.api.util.reflection.TypeKey;
 import com.dfsek.terra.config.pack.MetaPackImpl;
+import com.dfsek.terra.registry.CliExtensibleRegistry;
 import com.dfsek.terra.registry.OpenRegistryImpl;
 import com.dfsek.terra.registry.master.ConfigRegistry.PackLoadFailuresException;
 
@@ -35,7 +36,7 @@
 /**
  * Class to hold config packs
  */
-public class MetaConfigRegistry extends OpenRegistryImpl<MetaPack> {
+public class MetaConfigRegistry extends OpenRegistryImpl<MetaPack> implements CliExtensibleRegistry {
 
     public MetaConfigRegistry() {
         super(TypeKey.of(MetaPack.class));
@@ -45,8 +46,8 @@ public void loadAll(Platform platform, ConfigRegistry configRegistry) throws IOE
         Path packsDirectory = platform.getDataFolder().toPath().resolve("metapacks");
         Files.createDirectories(packsDirectory);
         List<IOException> failedLoads = new ArrayList<>();
-        try(Stream<Path> packs = Files.list(packsDirectory)) {
-            packs.forEach(path -> {
+        try(Stream<Path> paths = getMemberPaths(packsDirectory)) {
+            paths.forEach(path -> {
                 try {
                     MetaPack pack = new MetaPackImpl(path, platform, configRegistry);
                     registerChecked(pack.getRegistryKey(), pack);
@@ -59,4 +60,15 @@ public void loadAll(Platform platform, ConfigRegistry configRegistry) throws IOE
             throw new PackLoadFailuresException(failedLoads);
         }
     }
+
+    @Override
+    public String getRegistryName() {
+        return "metaconfig";
+    }
+
+    @Override
+    public boolean validatePathIsMember(Path path) {
+        var file = path.toFile();
+        return file.isDirectory() || file.getName().endsWith(".zip");
+    }
 }