diff --git a/config/backend.spec.php b/config/backend.spec.php
deleted file mode 100644
index 40bb1d8f..00000000
--- a/config/backend.spec.php
+++ /dev/null
@@ -1,37 +0,0 @@
-<?php
-
-/**
- * Last update: 2024-04-26
- *
- * servers.yaml backend spec.
- * This file defines the backend spec.
- * The dot (.) notation means the key is subarray of the parent key.
- * the boolean at the end of the key means if the key should be visible in the config:edit/view command.
- */
-return [
-    'name' => true,
-    'type' => true,
-    'url' => true,
-    'token' => true,
-    'uuid' => true,
-    'user' => true,
-    'export.enabled' => true,
-    'export.lastSync' => true,
-    'import.enabled' => true,
-    'import.lastSync' => true,
-    'webhook.token' => true,
-    'webhook.match.user' => true,
-    'webhook.match.uuid' => true,
-    'options.ignore' => true,
-    'options.LIBRARY_SEGMENT' => true,
-    'options.ADMIN_TOKEN' => false,
-    'options.DUMP_PAYLOAD' => false,
-    'options.DEBUG_TRACE' => false,
-    'options.IMPORT_METADATA_ONLY' => false,
-    'options.DRY_RUN' => false,
-    'options.client.timeout' => false,
-    'options.client.http_version' => false,
-    'options.use_old_progress_endpoint' => false,
-    'options.MAX_EPISODE_RANGE' => false,
-];
-
diff --git a/config/servers.spec.php b/config/servers.spec.php
index ad91c7c7..d54619e7 100644
--- a/config/servers.spec.php
+++ b/config/servers.spec.php
@@ -1,7 +1,7 @@
 <?php
 
 /**
- * Last update: 2024-05-14
+ * Last update: 2024-05-17
  *
  * servers.yaml backend spec.
  *
@@ -14,13 +14,15 @@ return [
         'type' => 'string',
         'visible' => true,
         'description' => 'The name of the backend.',
+        'immutable' => true,
     ],
     [
         'key' => 'type',
         'type' => 'string',
         'visible' => true,
         'description' => 'The type of the backend.',
-        'choices' => ['plex', 'emby', 'jellyfin']
+        'choices' => ['plex', 'emby', 'jellyfin'],
+        'immutable' => true,
     ],
     [
         'key' => 'url',
@@ -54,7 +56,7 @@ return [
     ],
     [
         'key' => 'export.lastSync',
-        'type' => 'integer',
+        'type' => 'int',
         'visible' => true,
         'description' => 'The last time data was exported to the backend.',
     ],
@@ -66,7 +68,7 @@ return [
     ],
     [
         'key' => 'import.lastSync',
-        'type' => 'integer',
+        'type' => 'int',
         'visible' => true,
         'description' => 'The last time data was imported from the backend.',
     ],
@@ -139,7 +141,7 @@ return [
     ],
     [
         'key' => 'options.client.timeout',
-        'type' => 'integer',
+        'type' => 'int',
         'visible' => false,
         'description' => 'The http timeout per request to the backend.',
     ],
diff --git a/src/API/Backend/Option.php b/src/API/Backend/Option.php
index cf5bc22a..24e90f74 100644
--- a/src/API/Backend/Option.php
+++ b/src/API/Backend/Option.php
@@ -31,26 +31,39 @@ final class Option
             return api_error('Invalid value for option path parameter.', HTTP_STATUS::HTTP_BAD_REQUEST);
         }
 
+        if (false === str_starts_with($option, 'options.')) {
+            return api_error(
+                "Invalid option. Option path parameter keys must start with 'options.'",
+                HTTP_STATUS::HTTP_BAD_REQUEST
+            );
+        }
+
+        $spec = getServerColumnSpec($option);
+        if (empty($spec)) {
+            return api_error(r("Invalid option '{key}'.", ['key' => $option]), HTTP_STATUS::HTTP_BAD_REQUEST);
+        }
+
         $list = ConfigFile::open(Config::get('backends_file'), 'yaml', autoCreate: true);
 
         if (false === $list->has($name)) {
             return api_error(r("Backend '{name}' not found.", ['name' => $name]), HTTP_STATUS::HTTP_NOT_FOUND);
         }
 
-        $key = $name . '.options.' . $option;
-
-        if (false === $list->has($key)) {
-            return api_error(r("Option '{option}' not found in backend '{name}'.", [
+        if (false === $list->has($name . '.' . $option)) {
+            return api_error(r("Option '{option}' not found in backend '{name}' config.", [
                 'option' => $option,
                 'name' => $name
             ]), HTTP_STATUS::HTTP_NOT_FOUND);
         }
 
-        $value = $list->get($key);
+        $value = $list->get($name . '.' . $option);
+        settype($value, ag($spec, 'type', 'string'));
+
         return api_response(HTTP_STATUS::HTTP_OK, [
-            'key' => $option,
+            'key' => $spec['key'],
             'value' => $value,
-            'type' => get_debug_type($value),
+            'type' => ag($spec, 'type', 'string'),
+            'description' => ag($spec, 'description', ''),
         ]);
     }
 
@@ -70,31 +83,38 @@ final class Option
         $data = DataUtil::fromRequest($request);
 
         if (null === ($option = $data->get('key'))) {
-            return api_error('Invalid value for key.', HTTP_STATUS::HTTP_BAD_REQUEST);
+            return api_error('No option key was given.', HTTP_STATUS::HTTP_BAD_REQUEST);
         }
 
-        $spec = require __DIR__ . '/../../../config/backend.spec.php';
-        $found = false;
-
-        foreach ($spec as $supportedKey => $_) {
-            if (str_ends_with($supportedKey, 'options.' . $option)) {
-                $found = true;
-                break;
-            }
+        if (false === str_starts_with($option, 'options.')) {
+            return api_error(
+                "Invalid option key was given. Option keys must start with 'options.'",
+                HTTP_STATUS::HTTP_BAD_REQUEST
+            );
         }
 
-        if (false === $found) {
-            return api_error(r("Option '{key}' is not supported.", ['key' => $option]), HTTP_STATUS::HTTP_BAD_REQUEST);
+        $spec = getServerColumnSpec($option);
+        if (empty($spec)) {
+            return api_error(r("Invalid option '{key}'.", ['key' => $option]), HTTP_STATUS::HTTP_BAD_REQUEST);
+        }
+
+        if ($list->has($name . '.' . $option)) {
+            return api_error(r("Option '{option}' already exists in backend '{name}'.", [
+                'option' => $option,
+                'name' => $name
+            ]), HTTP_STATUS::HTTP_CONFLICT);
         }
 
         $value = $data->get('value');
+        settype($value, ag($spec, 'type', 'string'));
 
-        $list->set($name . '.options.' . $option, $value)->persist();
+        $list->set($name . '.' . $option, $value)->persist();
 
         return api_response(HTTP_STATUS::HTTP_OK, [
             'key' => $option,
             'value' => $value,
-            'type' => get_debug_type($value),
+            'type' => ag($spec, 'type', 'string'),
+            'description' => ag($spec, 'description', ''),
         ]);
     }
 
@@ -109,34 +129,60 @@ final class Option
             return api_error('Invalid value for option parameter.', HTTP_STATUS::HTTP_BAD_REQUEST);
         }
 
-        $list = ConfigFile::open(Config::get('backends_file'), 'yaml', autoCreate: true);
+        if (false === str_starts_with($option, 'options.')) {
+            return api_error(
+                "Invalid option key was given. Option keys must start with 'options.'",
+                HTTP_STATUS::HTTP_BAD_REQUEST
+            );
+        }
 
+        $spec = getServerColumnSpec($option);
+        if (empty($spec)) {
+            return api_error(r("Invalid option '{key}'.", ['key' => $option]), HTTP_STATUS::HTTP_BAD_REQUEST);
+        }
+
+        $list = ConfigFile::open(Config::get('backends_file'), 'yaml', autoCreate: true);
         if (false === $list->has($name)) {
             return api_error(r("Backend '{name}' not found.", ['name' => $name]), HTTP_STATUS::HTTP_NOT_FOUND);
         }
 
-        $key = $name . '.options.' . $option;
-        if (false === $list->has($key)) {
-            return api_error(r("Option '{option}' not found in backend '{name}'.", [
+        if (false === $list->has($name . '.' . $option)) {
+            return api_error(r("Option '{option}' not found in backend '{name}' config.", [
                 'option' => $option,
                 'name' => $name
             ]), HTTP_STATUS::HTTP_NOT_FOUND);
         }
 
+        if (true === (bool)ag($spec, 'immutable', false)) {
+            return api_error(r("Option '{option}' is immutable.", [
+                'option' => $option,
+            ]), HTTP_STATUS::HTTP_CONFLICT);
+        }
+
         $data = DataUtil::fromRequest($request);
 
         if (null === ($value = $data->get('value'))) {
             return api_error(r("No value was provided for '{key}'.", [
-                'key' => $key,
+                'key' => $option,
             ]), HTTP_STATUS::HTTP_BAD_REQUEST);
         }
 
-        $list->set($key, $value)->persist();
+        settype($value, ag($spec, 'type', 'string'));
+
+        $oldValue = $list->get($name . '.' . $option);
+        if (null !== $oldValue) {
+            settype($oldValue, ag($spec, 'type', 'string'));
+        }
+
+        if ($oldValue !== $value) {
+            $list->set($name . '.' . $option, $value)->persist();
+        }
 
         return api_response(HTTP_STATUS::HTTP_OK, [
             'key' => $option,
             'value' => $value,
-            'type' => get_debug_type($value),
+            'type' => ag($spec, 'type', 'string'),
+            'description' => ag($spec, 'description', ''),
         ]);
     }
 
@@ -151,21 +197,40 @@ final class Option
             return api_error('Invalid value for option option parameter.', HTTP_STATUS::HTTP_BAD_REQUEST);
         }
 
-        $list = ConfigFile::open(Config::get('backends_file'), 'yaml', autoCreate: true);
+        if (false === str_starts_with($option, 'options.')) {
+            return api_error(
+                "Invalid option key was given. Option keys must start with 'options.'",
+                HTTP_STATUS::HTTP_BAD_REQUEST
+            );
+        }
 
+        $spec = getServerColumnSpec($option);
+        if (empty($spec)) {
+            return api_error(r("Invalid option '{key}'.", ['key' => $option]), HTTP_STATUS::HTTP_BAD_REQUEST);
+        }
+
+        $list = ConfigFile::open(Config::get('backends_file'), 'yaml', autoCreate: true);
         if (false === $list->has($name)) {
             return api_error(r("Backend '{name}' not found.", ['name' => $name]), HTTP_STATUS::HTTP_NOT_FOUND);
         }
 
-        $key = $name . '.options.' . $option;
+        if (false === $list->has($name . '.' . $option)) {
+            return api_error(r("Option '{option}' not found in backend '{name}' config.", [
+                'option' => $option,
+                'name' => $name
+            ]), HTTP_STATUS::HTTP_NOT_FOUND);
+        }
 
-        $value = $list->get($key);
-        $list->delete($key)->persist();
+        $value = $list->get($name . '.' . $option);
+        settype($value, ag($spec, 'type', 'string'));
+
+        $list->delete($option)->persist();
 
         return api_response(HTTP_STATUS::HTTP_OK, [
             'key' => $option,
             'value' => $value,
-            'type' => get_debug_type($value),
+            'type' => ag($spec, 'type', 'string'),
+            'description' => ag($spec, 'description', ''),
         ]);
     }
 }
diff --git a/src/API/Backend/Update.php b/src/API/Backend/Update.php
index da290ee6..779c0e09 100644
--- a/src/API/Backend/Update.php
+++ b/src/API/Backend/Update.php
@@ -20,6 +20,16 @@ final class Update
 {
     use APITraits;
 
+    private const array IMMUTABLE_KEYS = [
+        'name',
+        'type',
+        'options',
+        'webhook',
+        'webhook.match',
+        'import',
+        'export',
+    ];
+
     private ConfigFile $backendFile;
 
     public function __construct()
@@ -72,20 +82,23 @@ final class Update
                 HTTP_STATUS::HTTP_BAD_REQUEST);
         }
 
-        $spec = array_keys(require __DIR__ . '/../../../config/backend.spec.php');
-
         foreach ($data as $update) {
-            $key = ag($update, 'key');
             $value = ag($update, 'value');
 
-            if (null === $key) {
+            if (null === ($key = ag($update, 'key'))) {
                 return api_error('No key to update was present.', HTTP_STATUS::HTTP_BAD_REQUEST);
             }
 
-            if (false === in_array($key, $spec, true)) {
+            $spec = getServerColumnSpec($key);
+
+            if (empty($spec)) {
                 return api_error(r('Invalid key to update: {key}', ['key' => $key]), HTTP_STATUS::HTTP_BAD_REQUEST);
             }
 
+            if (in_array($key, self::IMMUTABLE_KEYS, true)) {
+                return api_error(r('Key {key} is immutable.', ['key' => $key]), HTTP_STATUS::HTTP_BAD_REQUEST);
+            }
+
             $this->backendFile->set("{$name}.{$key}", $value);
         }
 
@@ -125,14 +138,15 @@ final class Update
             ],
         ];
 
-        $spec = require __DIR__ . '/../../../config/backend.spec.php';
-
         foreach ($data->get('options', []) as $key => $value) {
-            if (false === ag_exists($spec, "options.{$key}") || null === $value) {
+            $key = "options.{$key}";
+            $spec = getServerColumnSpec($key);
+
+            if (empty($spec) || null === $value) {
                 continue;
             }
 
-            $newData = ag_set($newData, "options.{$key}", $value);
+            $newData = ag_set($newData, $key, $value);
         }
 
         return deepArrayMerge([$config, $client->fromRequest($newData, $request)]);
diff --git a/src/API/Backends/Add.php b/src/API/Backends/Add.php
index 466f48dd..3c82f370 100644
--- a/src/API/Backends/Add.php
+++ b/src/API/Backends/Add.php
@@ -148,14 +148,15 @@ final class Add
             'options' => [],
         ];
 
-        $spec = require __DIR__ . '/../../../config/backend.spec.php';
-
         foreach ($data->get('options', []) as $key => $value) {
-            if (false === ag_exists($spec, "options.{$key}") || null === $value) {
+            $key = "options.{$key}";
+            $spec = getServerColumnSpec($key);
+
+            if (empty($spec) || null === $value) {
                 continue;
             }
 
-            $config = ag_set($config, "options.{$key}", $value);
+            $config = ag_set($config, $key, $value);
         }
 
         return $client->fromRequest($config, $request);
diff --git a/src/Commands/Config/EditCommand.php b/src/Commands/Config/EditCommand.php
index 6fff16e4..89fc8edb 100644
--- a/src/Commands/Config/EditCommand.php
+++ b/src/Commands/Config/EditCommand.php
@@ -24,7 +24,7 @@ use Throwable;
 #[Cli(command: self::ROUTE)]
 final class EditCommand extends Command
 {
-    public const ROUTE = 'config:edit';
+    public const string ROUTE = 'config:edit';
 
     public function __construct(private LoggerInterface $logger)
     {
@@ -75,13 +75,7 @@ final class EditCommand extends Command
                             ', ',
                             array_map(
                                 fn($val) => '<value>' . $val . '</value>',
-                                array_keys(
-                                    array_filter(
-                                        array: require __DIR__ . '/../../../config/backend.spec.php',
-                                        callback: fn($val, $key) => $val,
-                                        mode: ARRAY_FILTER_USE_BOTH
-                                    )
-                                )
+                                array_column(require __DIR__ . '/../../../config/servers.spec.php', 'key')
                             ),
                         )
                     ]
@@ -232,13 +226,13 @@ final class EditCommand extends Command
 
             $suggest = [];
 
-            foreach (require __DIR__ . '/../../../config/backend.spec.php' as $name => $val) {
-                if (false === $val) {
+            foreach (require __DIR__ . '/../../../config/servers.spec.php' as $column) {
+                if (false === (bool)ag($column, 'visible', false)) {
                     continue;
                 }
 
-                if (empty($currentValue) || str_starts_with($name, $currentValue)) {
-                    $suggest[] = $name;
+                if (empty($currentValue) || str_starts_with(ag($column, 'key', ''), $currentValue)) {
+                    $suggest[] = ag($column, 'key', '');
                 }
             }
 
diff --git a/src/Commands/Config/ViewCommand.php b/src/Commands/Config/ViewCommand.php
index 920d87ba..25e6aa25 100644
--- a/src/Commands/Config/ViewCommand.php
+++ b/src/Commands/Config/ViewCommand.php
@@ -26,7 +26,7 @@ use Symfony\Component\Yaml\Yaml;
 #[Cli(command: self::ROUTE)]
 final class ViewCommand extends Command
 {
-    public const ROUTE = 'config:view';
+    public const string ROUTE = 'config:view';
 
     /**
      * Configure the command.
@@ -177,8 +177,10 @@ final class ViewCommand extends Command
 
             $suggest = [];
 
-            foreach (require __DIR__ . '/../../../config/backend.spec.php' as $name => $val) {
-                if (true === $val && (empty($currentValue) || str_starts_with($name, $currentValue))) {
+            foreach (require __DIR__ . '/../../../config/servers.spec.php' as $column) {
+                $name = ag($column, 'key', '');
+                $visible = (bool)ag($column, 'visible', false);
+                if ($visible && (empty($currentValue) || str_starts_with($name, $currentValue))) {
                     $suggest[] = $name;
                 }
             }
diff --git a/src/Libs/helpers.php b/src/Libs/helpers.php
index 68c716fd..d70012ba 100644
--- a/src/Libs/helpers.php
+++ b/src/Libs/helpers.php
@@ -1442,3 +1442,55 @@ if (!function_exists('APIRequest')) {
         return new APIResponse($response->getStatusCode(), $response->getHeaders(), [], $response->getBody());
     }
 }
+
+if (!function_exists('getServerColumnSpec')) {
+    /**
+     * Returns the spec for the given server column.
+     *
+     * @param string $column
+     *
+     * @return array The spec for the given column. Otherwise, an empty array.
+     */
+    function getServerColumnSpec(string $column): array
+    {
+        static $_serverSpec = null;
+
+        if (null === $_serverSpec) {
+            $_serverSpec = require __DIR__ . '/../../config/servers.spec.php';
+        }
+
+        foreach ($_serverSpec as $spec) {
+            if (ag($spec, 'key') === $column) {
+                return $spec;
+            }
+        }
+
+        return [];
+    }
+}
+
+if (!function_exists('getEnvSpec')) {
+    /**
+     * Returns the spec for the given environment variable.
+     *
+     * @param string $env
+     *
+     * @return array The spec for the given column. Otherwise, an empty array.
+     */
+    function getEnvSpec(string $env): array
+    {
+        static $_envSpec = null;
+
+        if (null === $_envSpec) {
+            $_envSpec = require __DIR__ . '/../../config/env.spec.php';
+        }
+
+        foreach ($_envSpec as $spec) {
+            if (ag($spec, 'key') === $env) {
+                return $spec;
+            }
+        }
+
+        return [];
+    }
+}