diff --git a/docs/MIXED_CPP_PHP.md b/docs/MIXED_CPP_PHP.md
index ff333684..4ac3ff8b 100644
--- a/docs/MIXED_CPP_PHP.md
+++ b/docs/MIXED_CPP_PHP.md
@@ -698,6 +698,20 @@ function vector_new(int $size, bool $init = false): mixed {}
 外部 stub 中的类会在消费项目中生成类注册、属性和常量实体，但不生成 `php_*` 方法本体；方法本体由动态库提供。
 Property hook 同样按方法处理：发布 stub 保留 `get`/`set` 的声明并移除实现，消费项目生成属性实体，hook 的 getter/setter `php_*` 实现从动态库导入。
 
+库内部声明可使用编译期 Attribute `#[NoExport]` 从公开 ABI 排除：
+
+```php
+#[\NoExport]
+function internal_helper(): void {}
+
+#[\NoExport]
+class InternalService {}
+```
+
+声明仍参与当前库编译，但不会进入 `<target>.stub.php`，对应 `php_*` 符号也不添加 library export 修饰。类注解会级联到其全部方法；单个方法也可以独立标记。`NoExport` 位于根命名空间：全局命名空间可写 `#[NoExport]`，其他命名空间必须写 `#[\NoExport]`，并且该编译期 Attribute 不会进入运行时元数据。
+
+`NoExport` 与 `ExtensionProvider` 都遵循 PHP 类名解析规则，支持完全限定名、`use` 和 `use ... as ...` 别名。只有解析结果严格指向根命名空间内建 Attribute 时，编译器才会消费它。
+
 `php_<target>_func_decl.h` 和 `php_<target>_data_decl.h` 都是 TypePHP 构建过程的内部生成文件，不是库的对外开发头文件。
 `func_decl.h` 在 `-m lib` 构建时还会被强制包含，用于给当前 target 的 `php_*` C++ ABI 函数添加平台导出标记；`data_decl.h` 仅在 target 内部声明全局变量、字面量、常量对象和运行时映射等数据。
 
diff --git a/phpunit/code/compiler_api/library_import_global.php b/phpunit/code/compiler_api/library_import_global.php
new file mode 100644
index 00000000..d85515da
--- /dev/null
+++ b/phpunit/code/compiler_api/library_import_global.php
@@ -0,0 +1,7 @@
+<?php
+
+#[NoExport]
+function global_hidden(): int
+{
+    return 42;
+}
diff --git a/phpunit/code/compiler_api/library_import_native.stub.php b/phpunit/code/compiler_api/library_import_native.stub.php
index cde5c6b2..5f77bfec 100644
--- a/phpunit/code/compiler_api/library_import_native.stub.php
+++ b/phpunit/code/compiler_api/library_import_native.stub.php
@@ -2,6 +2,8 @@
 
 namespace LibraryApi;
 
+use \NoExport;
+
 class NativeCounter
 {
     public const int INITIAL = 3;
@@ -11,3 +13,6 @@ class NativeCounter
 }
 
 function native_value(string $name = 'typephp'): string {}
+
+#[NoExport]
+function native_hidden(): int {}
diff --git a/phpunit/code/compiler_api/library_import_php.php b/phpunit/code/compiler_api/library_import_php.php
index bdfdd0c5..3a1ce786 100644
--- a/phpunit/code/compiler_api/library_import_php.php
+++ b/phpunit/code/compiler_api/library_import_php.php
@@ -2,6 +2,10 @@
 
 namespace LibraryApi;
 
+use \ExtensionProvider as Provider;
+use \NoExport as Internal;
+use \Type;
+
 class Counter
 {
     public const int STEP = 2;
@@ -20,9 +24,40 @@ class Counter
         $this->value += $amount;
         return $this->value;
     }
+
+    #[Internal]
+    public function reset(): void
+    {
+        $this->value = 0;
+    }
+}
+
+#[Internal]
+class InternalCounter
+{
+    public function value(): int
+    {
+        return 42;
+    }
+}
+
+#[Internal]
+#[Provider(Type::String)]
+class InternalStringExtension
+{
+    public static function byteLength(string $value): int
+    {
+        return strlen($value);
+    }
 }
 
 function twice(int $value): int
 {
     return $value * 2;
 }
+
+#[Internal]
+function internal_twice(int $value = 2): int
+{
+    return $value * 2;
+}
diff --git a/phpunit/code/compiler_api/library_no_export_namespace.php b/phpunit/code/compiler_api/library_no_export_namespace.php
new file mode 100644
index 00000000..4b8ec4ef
--- /dev/null
+++ b/phpunit/code/compiler_api/library_no_export_namespace.php
@@ -0,0 +1,36 @@
+<?php
+
+namespace App\XX;
+
+use \NoExport;
+use NoExport as Hidden;
+
+#[NoExport]
+function imported_attribute(): int
+{
+    return 1;
+}
+
+#[Hidden]
+function aliased_attribute(): int
+{
+    return 2;
+}
+
+#[\NoExport]
+function fully_qualified_attribute(): int
+{
+    return 3;
+}
+
+#[namespace\NoExport]
+function relative_attribute(): int
+{
+    return 4;
+}
+
+#[App\XX\NoExport]
+function qualified_attribute(): int
+{
+    return 5;
+}
diff --git a/phpunit/src/CompilerBaseApiTest.php b/phpunit/src/CompilerBaseApiTest.php
index 8083e984..2d3c3017 100644
--- a/phpunit/src/CompilerBaseApiTest.php
+++ b/phpunit/src/CompilerBaseApiTest.php
@@ -923,12 +923,19 @@ YAML);
         $files = [
             ROOT_PATH . '/phpunit/code/compiler_api/library_import_php.php',
             ROOT_PATH . '/phpunit/code/compiler_api/library_import_native.stub.php',
+            ROOT_PATH . '/phpunit/code/compiler_api/library_import_global.php',
         ];
         $this->compiler->addFiles($files);
         foreach ($files as $file) {
             $this->compiler->prepareFile($file);
             $this->compiler->convertFile($file);
+            $this->assertStringNotContainsString(
+                'NoExport',
+                file_get_contents($this->compiler->getArgInfoHeaderFile($file)),
+            );
         }
+        $provider = $this->invokeMethod('getClass', 'LibraryApi\\InternalStringExtension');
+        $this->assertSame(Type::STR, $provider->extensionProviderTarget);
 
         $stubFile = $this->compiler->genLibraryImportStub($files);
         $stub = file_get_contents($stubFile);
@@ -947,10 +954,53 @@ YAML);
         $this->assertStringContainsString('function native_value(string $name = \'typephp\'): string', $stub);
         $this->assertStringContainsString('class NativeCounter', $stub);
         $this->assertStringContainsString('function bump(int $amount): int', $stub);
+        $this->assertStringNotContainsString('function reset()', $stub);
+        $this->assertStringNotContainsString('class InternalCounter', $stub);
+        $this->assertStringNotContainsString('class InternalStringExtension', $stub);
+        $this->assertStringNotContainsString('function internal_twice(', $stub);
+        $this->assertStringNotContainsString('function native_hidden(', $stub);
+        $this->assertStringNotContainsString('function global_hidden(', $stub);
+        $this->assertStringNotContainsString('NoExport', $stub);
         $this->assertStringNotContainsString('return $this->value', $stub);
         $this->assertStringNotContainsString('intdiv($value, 2)', $stub);
         $this->assertStringNotContainsString('return $value * 2', $stub);
 
+        $libraryHeaderFile = $this->testDir . '/php_prime2_func_decl.h';
+        $this->compiler->genFunctionDeclarations($libraryHeaderFile);
+        $libraryHeader = file_get_contents($libraryHeaderFile);
+        $this->assertStringContainsString(
+            'TYPEPHP_PRIME2_API php::Int php_libraryapi__twice(',
+            $libraryHeader,
+        );
+        $this->assertStringContainsString(
+            'extern php::Int php_libraryapi__internal_twice(',
+            $libraryHeader,
+        );
+        $this->assertStringContainsString(
+            'extern php::Int php_libraryapi__internalcounter__value(',
+            $libraryHeader,
+        );
+        $this->assertStringContainsString(
+            'extern php::Int php_libraryapi__internalstringextension__bytelength(',
+            $libraryHeader,
+        );
+        $this->assertStringContainsString(
+            'extern void php_libraryapi__counter__reset(',
+            $libraryHeader,
+        );
+        $this->assertStringContainsString(
+            'extern php::Int php_libraryapi__native_hidden(',
+            $libraryHeader,
+        );
+        $this->assertStringContainsString(
+            'extern php::Int php_global_hidden(',
+            $libraryHeader,
+        );
+        $this->assertStringContainsString(
+            'extern php::Int php_libraryapi__internal_twice_arg_0_default_value();',
+            $libraryHeader,
+        );
+
         $consumerDir = $this->testDir . '/consumer';
         mkdir($consumerDir, 0777, true);
         $consumer = CompilerTest::create($consumerDir);
@@ -1007,6 +1057,24 @@ YAML);
         $this->assertSame(['prime2'], $consumer->getLinkLibs());
     }
 
+    public function testNoExportFollowsPhpNamespaceResolution(): void
+    {
+        $this->setPropertyValue('buildMode', CompilerBase::BUILD_MODE_LIB);
+        $this->setPropertyValue('outputDir', $this->testDir);
+        $this->compiler->setTargetName('namespace_rules');
+
+        $stubFile = $this->compiler->genLibraryImportStub([
+            ROOT_PATH . '/phpunit/code/compiler_api/library_no_export_namespace.php',
+        ]);
+        $stub = file_get_contents($stubFile);
+
+        $this->assertStringNotContainsString('function imported_attribute(): int', $stub);
+        $this->assertStringNotContainsString('function aliased_attribute(): int', $stub);
+        $this->assertStringNotContainsString('function fully_qualified_attribute(): int', $stub);
+        $this->assertStringContainsString('function relative_attribute(): int', $stub);
+        $this->assertStringContainsString('function qualified_attribute(): int', $stub);
+    }
+
     public function testLibraryCompileOptionsExportOnlyPublicApiByDefault(): void
     {
         $this->setPropertyValue('buildMode', CompilerBase::BUILD_MODE_LIB);
diff --git a/src/Entity/ClassDef.php b/src/Entity/ClassDef.php
index 54d3215b..ae6f4649 100644
--- a/src/Entity/ClassDef.php
+++ b/src/Entity/ClassDef.php
@@ -32,6 +32,8 @@ class ClassDef extends ClassLikeDef
     public string $extends = '';
     public bool $requireCtor = false;
     public bool $enum = false;
+    /** Whether this class and its methods are part of the public ABI of a library build. */
+    public bool $exported = true;
     public ?string $extensionProviderTarget = null;
 
     /**
diff --git a/src/Entity/FunctionDef.php b/src/Entity/FunctionDef.php
index 2715c1ba..53929c3a 100644
--- a/src/Entity/FunctionDef.php
+++ b/src/Entity/FunctionDef.php
@@ -25,6 +25,8 @@ class FunctionDef
     public string $namespace;
     public bool $method = false;
     public bool $stub = false;
+    /** Whether this function is part of the public ABI of a library build. */
+    public bool $exported = true;
     /** External library imported by the stub containing this function. */
     public string $importLibrary = '';
     public bool $returnTypeUndeclared = false;
diff --git a/src/Generator/LibraryImportStubGenerator.php b/src/Generator/LibraryImportStubGenerator.php
index 88ce614a..3cffb546 100644
--- a/src/Generator/LibraryImportStubGenerator.php
+++ b/src/Generator/LibraryImportStubGenerator.php
@@ -47,7 +47,7 @@ final class LibraryImportStubGenerator
             }
             $ast = $this->parser->parse($code) ?? [];
             $traverser = new NodeTraverser();
-            $traverser->addVisitor(new NameResolver());
+            $traverser->addVisitor(new NameResolver(null, ['preserveOriginalNames' => true]));
             $ast = $traverser->traverse($ast);
 
             foreach ($ast as $stmt) {
@@ -98,6 +98,10 @@ final class LibraryImportStubGenerator
 
     private function makeImportDeclaration(Node\Stmt $stmt): ?Node\Stmt
     {
+        if ($this->hasNoExportAttribute($stmt)) {
+            return null;
+        }
+
         $comments = array_filter(
             $stmt->getComments(),
             static fn(\PhpParser\Comment $comment): bool => preg_match(
@@ -116,6 +120,9 @@ final class LibraryImportStubGenerator
             $members = [];
             foreach ($stmt->stmts as $member) {
                 if ($member instanceof Node\Stmt\ClassMethod) {
+                    if ($this->hasNoExportAttribute($member)) {
+                        continue;
+                    }
                     if (!($member->flags & Modifiers::ABSTRACT)
                         && !($stmt instanceof Node\Stmt\Interface_)) {
                         $member->stmts = [];
@@ -144,4 +151,21 @@ final class LibraryImportStubGenerator
 
         return null;
     }
+
+    private function hasNoExportAttribute(Node $node): bool
+    {
+        if (!property_exists($node, 'attrGroups')) {
+            return false;
+        }
+        foreach ($node->attrGroups as $group) {
+            foreach ($group->attrs as $attribute) {
+                $parts = $attribute->name->getParts();
+                if (count($parts) === 1 && strcasecmp($parts[0], 'NoExport') === 0) {
+                    return true;
+                }
+            }
+        }
+
+        return false;
+    }
 }
diff --git a/src/Preprocessor.php b/src/Preprocessor.php
index 17c77fe7..c94bde60 100644
--- a/src/Preprocessor.php
+++ b/src/Preprocessor.php
@@ -29,6 +29,7 @@ use PhpParser\Node\UnionType;
 use PhpParser\NodeAbstract;
 use PhpParser\NodeFinder;
 use PhpParser\NodeTraverser;
+use PhpParser\NodeVisitor\NameResolver;
 
 class Preprocessor extends CompilerBase
 {
@@ -136,6 +137,7 @@ class Preprocessor extends CompilerBase
             }
 
             $traverser = new NodeTraverser();
+            $traverser->addVisitor(new NameResolver(null, ['replaceNodes' => false]));
             $traverser->addVisitor(new Visitor());
             $stmts = $traverser->traverse($ast);
             $this->validateUnsupportedAttributeArguments($stmts);
@@ -216,6 +218,37 @@ class Preprocessor extends CompilerBase
         return false;
     }
 
+    private function hasNoExportAttribute(NodeAbstract $node): bool
+    {
+        foreach ($node->attrGroups as $group) {
+            foreach ($group->attrs as $attribute) {
+                if (!$this->isRootCompileTimeAttribute($attribute, 'NoExport')) {
+                    continue;
+                }
+                if ($attribute->args !== []) {
+                    $this->fatalError($attribute, 'NoExport does not accept arguments');
+                }
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+    private function isRootCompileTimeAttribute(Node\Attribute $attribute, string $name): bool
+    {
+        return strcasecmp($this->getResolvedPhpName($attribute->name), $name) === 0;
+    }
+
+    private function getResolvedPhpName(Node\Name $name): string
+    {
+        $resolvedName = $name->getAttribute('resolvedName')
+            ?? $name->getAttribute('namespacedName')
+            ?? $name;
+
+        return ltrim($resolvedName->toString(), '\\');
+    }
+
     private function getExternalImportLibraryName(string $stubFile): string
     {
         $name = basename($stubFile, '.stub.php');
@@ -500,6 +533,7 @@ class Preprocessor extends CompilerBase
         }
 
         $functionDef = new FunctionDef($fnName, $returnType, $this->namespace);
+        $functionDef->exported = !($this->classDef?->exported === false || $this->hasNoExportAttribute($v));
         $functionDef->returnClass = $class;
         // Record late-bound return type keywords so they can be re-resolved to
         // the consuming class when a trait method is flattened into a class.
@@ -627,6 +661,7 @@ class Preprocessor extends CompilerBase
         }
 
         $this->classDef = new ClassDef($this->class, $flags, $this->namespace);
+        $this->classDef->exported = !$this->hasNoExportAttribute($class);
         $this->classDef->extensionProviderTarget = $this->parseExtensionProviderTarget($class);
         $this->addClass($fullClassName, $this->classDef);
 
@@ -723,8 +758,7 @@ class Preprocessor extends CompilerBase
     {
         foreach ($class->attrGroups as $groupIndex => $group) {
             foreach ($group->attrs as $attributeIndex => $attribute) {
-                $parts = $attribute->name->getParts();
-                if (strtolower((string) end($parts)) !== 'extensionprovider') {
+                if (!$this->isRootCompileTimeAttribute($attribute, 'ExtensionProvider')) {
                     continue;
                 }
                 if (!$class instanceof Node\Stmt\Class_) {
@@ -754,10 +788,10 @@ class Preprocessor extends CompilerBase
         if ($value instanceof Node\Expr\ClassConstFetch
             && $this->isNameExpr($value->class)
             && $this->isIdExpr($value->name)) {
-            $class = ltrim($value->class->toString(), '\\');
+            $class = $this->getResolvedPhpName($value->class);
             $constant = $value->name->toString();
             if (strtolower($constant) === 'class') {
-                return $this->getNamespacedClassName($value->class->toString());
+                return $class;
             }
             $targets = [
                 'Int' => Type::INT,
diff --git a/src/Translator.php b/src/Translator.php
index d3e53f7e..ecce536d 100644
--- a/src/Translator.php
+++ b/src/Translator.php
@@ -43,6 +43,7 @@ use PhpParser\Modifiers;
 use PhpParser\Node;
 use PhpParser\NodeAbstract;
 use PhpParser\NodeTraverser;
+use PhpParser\NodeVisitor\NameResolver;
 
 class Translator extends Preprocessor
 {
@@ -1649,7 +1650,7 @@ CODE;
         if ($this->isImportedFunction($function)) {
             return $this->getNamedLibraryImportMacroName($function->importLibrary) . ' ';
         }
-        if ($this->isBuildModeLib()) {
+        if ($this->isBuildModeLib() && $function->exported) {
             return $this->getLibraryApiMacroName() . ' ';
         }
         return 'extern ';
@@ -2285,6 +2286,7 @@ CODE;
 
         $ast = $this->parser->parse($phpCode);
         $traverser = new NodeTraverser();
+        $traverser->addVisitor(new NameResolver(null, ['replaceNodes' => false]));
         $traverser->addVisitor(new Visitor());
 
         $stmts = $traverser->traverse($ast);
diff --git a/src/gen_stub.php b/src/gen_stub.php
index c19ee29a..cc408c51 100755
--- a/src/gen_stub.php
+++ b/src/gen_stub.php
@@ -3583,7 +3583,9 @@ class AttributeInfo {
         foreach ($attributeGroups as $attrGroup) {
             foreach ($attrGroup->attrs as $attr) {
                 $parts = $attr->name->getParts();
-                if (strtolower((string) end($parts)) === 'extensionprovider') {
+                $compileTimeAttribute = count($parts) === 1
+                    && in_array(strtolower($parts[0]), ['extensionprovider', 'noexport'], true);
+                if ($compileTimeAttribute) {
                     continue;
                 }
                 $attributes[] = new AttributeInfo($attr->name->toString(), $attr->args);
@@ -4506,7 +4508,10 @@ class FileInfo {
         $parser = (new PhpParser\ParserFactory())->createForVersion(PhpParser\PhpVersion::fromString($phpVersion));
         $nodeTraverser = new PhpParser\NodeTraverser;
         $nodeTraverser->addVisitor(new TypePhp\Transform\Visitor());
-        $nodeTraverser->addVisitor(new PhpParser\NodeVisitor\NameResolver);
+        $nodeTraverser->addVisitor(new PhpParser\NodeVisitor\NameResolver(
+            null,
+            ['preserveOriginalNames' => true]
+        ));
         $prettyPrinter = new class extends Standard {
             protected function pName_FullyQualified(PhpParser\Node\Name\FullyQualified $node): string {
                 return implode('\\', $node->getParts());
diff --git a/src/polyfills.php b/src/polyfills.php
index f6478689..1b823c52 100644
--- a/src/polyfills.php
+++ b/src/polyfills.php
@@ -14,6 +14,11 @@ final readonly class ExtensionProvider
     }
 }
 
+#[Attribute(Attribute::TARGET_CLASS | Attribute::TARGET_FUNCTION | Attribute::TARGET_METHOD)]
+final readonly class NoExport
+{
+}
+
 /**
  * Public compile-time type symbols shared by extension providers and std containers.
  * This root class is deliberately distinct from the compiler-internal TypePhp\Type.