diff --git a/src/Contracts/DefinesFeaturesExternally.php b/src/Contracts/DefinesFeaturesExternally.php
new file mode 100644
index 0000000..86e3e18
--- /dev/null
+++ b/src/Contracts/DefinesFeaturesExternally.php
@@ -0,0 +1,13 @@
+<?php
+
+namespace Laravel\Pennant\Contracts;
+
+interface DefinesFeaturesExternally
+{
+    /**
+     * Retrieve the defined features for the given scope.
+     *
+     * @return list<string>
+     */
+    public function definedFeaturesForScope(mixed $scope): array;
+}
diff --git a/src/Drivers/Decorator.php b/src/Drivers/Decorator.php
index ed0ff6c..363c9dd 100644
--- a/src/Drivers/Decorator.php
+++ b/src/Drivers/Decorator.php
@@ -10,6 +10,7 @@
 use Illuminate\Support\Str;
 use Illuminate\Support\Traits\Macroable;
 use Laravel\Pennant\Contracts\CanListStoredFeatures;
+use Laravel\Pennant\Contracts\DefinesFeaturesExternally;
 use Laravel\Pennant\Contracts\Driver;
 use Laravel\Pennant\Contracts\FeatureScopeable;
 use Laravel\Pennant\Events\AllFeaturesPurged;
@@ -620,6 +621,12 @@ public function instance($name)
      */
     public function definedFeaturesForScope($scope)
     {
+        $scope = $this->resolveScope($scope);
+
+        if ($this->driver instanceof DefinesFeaturesExternally) {
+            return collect($this->driver->definedFeaturesForScope($scope));
+        }
+
         return collect($this->nameMap)
             ->only($this->defined())
             ->filter(function ($resolver) use ($scope) {
diff --git a/tests/Feature/DefinesFeaturesExternallyTest.php b/tests/Feature/DefinesFeaturesExternallyTest.php
new file mode 100644
index 0000000..011fcae
--- /dev/null
+++ b/tests/Feature/DefinesFeaturesExternallyTest.php
@@ -0,0 +1,73 @@
+<?php
+
+namespace Tests\Feature;
+
+use Illuminate\Support\Facades\Config;
+use Laravel\Pennant\Contracts\DefinesFeaturesExternally;
+use Laravel\Pennant\Contracts\FeatureScopeable;
+use Laravel\Pennant\Drivers\ArrayDriver;
+use Laravel\Pennant\Feature;
+use Tests\TestCase;
+
+class DefinesFeaturesExternallyTest extends TestCase
+{
+    public function test_it_can_retrieve_all_features_when_features_are_defined_externally()
+    {
+        $driver = new class(app('events'), []) extends ArrayDriver implements DefinesFeaturesExternally
+        {
+            /**
+             * Retrieve the defined features for the given scope.
+             *
+             * @return list<string>
+             */
+            public function definedFeaturesForScope(mixed $scope): array
+            {
+                return [
+                    'feature-1',
+                    'feature-2',
+                ];
+            }
+        };
+        Feature::extend('external', fn () => $driver);
+        Config::set('pennant.stores.external', ['driver' => 'external']);
+
+        $features = Feature::driver('external')->all();
+
+        $this->assertSame([
+            'feature-1' => false,
+            'feature-2' => false,
+        ], $features);
+    }
+
+    public function test_when_features_are_defined_externally_that_scope_is_correctly_resolved()
+    {
+        $driver = new class(app('events'), []) extends ArrayDriver implements DefinesFeaturesExternally
+        {
+            /**
+             * Retrieve the defined features for the given scope.
+             *
+             * @return list<string>
+             */
+            public function definedFeaturesForScope(mixed $scope): array
+            {
+                return [
+                    $scope,
+                ];
+            }
+        };
+        Feature::extend('external', fn () => $driver);
+        Config::set('pennant.stores.external', ['driver' => 'external']);
+
+        $features = Feature::driver('external')->for(new class implements FeatureScopeable
+        {
+            public function toFeatureIdentifier(string $driver): mixed
+            {
+                return 'scope-value';
+            }
+        })->all();
+
+        $this->assertSame([
+            'scope-value' => false,
+        ], $features);
+    }
+}