There's no valid use-case to implement Scope or FunctionReflection

src/Rules/Api/ApiClassImplementsRule.php

@@ -5,6 +5,7 @@
 use PhpParser\Node;
 use PhpParser\Node\Stmt\Class_;
 use PHPStan\Analyser\Scope;
+use PHPStan\Reflection\FunctionReflection;
 use PHPStan\Reflection\ReflectionProvider;
 use PHPStan\Rules\Rule;
 use PHPStan\Rules\RuleError;
@@ -69,6 +70,8 @@ private function checkName(Scope $scope, Node\Name $name): array
 		if (in_array($implementedClassReflection->getName(), [
 			Type::class,
 			ReflectionProvider::class,
+			Scope::class,
+			FunctionReflection::class,
 		], true)) {
 			return [$ruleError];
 		}

tests/PHPStan/Rules/Api/ApiClassImplementsRuleTest.php

@@ -45,6 +45,16 @@ public function testRuleOutOfPhpStan(): void
 				322,
 				$tip,
 			],
+			[
+				'Implementing PHPStan\Analyser\Scope is not covered by backward compatibility promise. The interface might change in a minor PHPStan version.',
+				327,
+				$tip,
+			],
+			[
+				'Implementing PHPStan\Reflection\FunctionReflection is not covered by backward compatibility promise. The interface might change in a minor PHPStan version.',
+				332,
+				$tip,
+			],
 		]);
 	}
 

tests/PHPStan/Rules/Api/data/class-implements-out-of-phpstan.php

@@ -323,3 +323,13 @@ abstract class Dolor implements ReflectionProvider
 {
 
 }
+
+abstract class MyScope implements Scope
+{
+
+}
+
+abstract class MyFunctionReflection implements FunctionReflection
+{
+
+}