fixup! wip

Signed-off-by: provokateurin <kate@provokateurin.de>

.gitignore

@@ -38,6 +38,7 @@ node_modules/
 !/apps/profile
 !/apps/provisioning_api
 !/apps/settings
+!/apps/sharing
 !/apps/systemtags
 !/apps/testing
 !/apps/admin_audit

REUSE.toml

@@ -400,7 +400,7 @@ SPDX-FileCopyrightText = "2019 Fabian Wiktor <https://www.pexels.com/photo/green
 SPDX-License-Identifier = "CC0-1.0"
 
 [[annotations]]
-path = ["openapi.json", ".envrc", "flake.nix", "flake.lock", "build/eslint-baseline.json", "build/eslint-baseline-legacy.json"]
+path = ["openapi.json", ".envrc", "flake.nix", "flake.lock", "build/eslint-baseline.json", "build/eslint-baseline-legacy.json", "apps/sharing/openapi.json"]
 precedence = "aggregate"
 SPDX-FileCopyrightText = "2025 Nextcloud GmbH and Nextcloud contributors"
 SPDX-License-Identifier = "AGPL-3.0-or-later"

apps/files/composer/composer/autoload_classmap.php

@@ -95,4 +95,5 @@ return array(
     'OCA\\Files\\Service\\ViewConfig' => $baseDir . '/../lib/Service/ViewConfig.php',
     'OCA\\Files\\Settings\\AdminSettings' => $baseDir . '/../lib/Settings/AdminSettings.php',
     'OCA\\Files\\Settings\\PersonalSettings' => $baseDir . '/../lib/Settings/PersonalSettings.php',
+    'OCA\\Files\\Sharing\\SourceType\\NodeShareSourceType' => $baseDir . '/../lib/Sharing/SourceType/NodeShareSourceType.php',
 );

apps/files/composer/composer/autoload_static.php

@@ -110,6 +110,7 @@ class ComposerStaticInitFiles
         'OCA\\Files\\Service\\ViewConfig' => __DIR__ . '/..' . '/../lib/Service/ViewConfig.php',
         'OCA\\Files\\Settings\\AdminSettings' => __DIR__ . '/..' . '/../lib/Settings/AdminSettings.php',
         'OCA\\Files\\Settings\\PersonalSettings' => __DIR__ . '/..' . '/../lib/Settings/PersonalSettings.php',
+        'OCA\\Files\\Sharing\\SourceType\\NodeShareSourceType' => __DIR__ . '/..' . '/../lib/Sharing/SourceType/NodeShareSourceType.php',
     );
 
     public static function getInitializer(ClassLoader $loader)

apps/files/lib/AppInfo/Application.php

@@ -30,6 +30,8 @@ use OCA\Files\Search\FilesSearchProvider;
 use OCA\Files\Service\TagService;
 use OCA\Files\Service\UserConfig;
 use OCA\Files\Service\ViewConfig;
+use OCA\Files\Sharing\SourceType\NodeShareSourceType;
+use OCA\Sharing\Registry;
 use OCP\Activity\IManager as IActivityManager;
 use OCP\AppFramework\App;
 use OCP\AppFramework\Bootstrap\IBootContext;
@@ -52,6 +54,7 @@ use OCP\IRequest;
 use OCP\IServerContainer;
 use OCP\ITagManager;
 use OCP\IUserSession;
+use OCP\Server;
 use OCP\Share\IManager as IShareManager;
 use OCP\Util;
 use Psr\Container\ContainerInterface;
@@ -128,6 +131,7 @@ class Application extends App implements IBootstrap {
 
 		$context->registerConfigLexicon(ConfigLexicon::class);
 
+		Server::get(Registry::class)->registerSourceType(new NodeShareSourceType());
 	}
 
 	public function boot(IBootContext $context): void {

apps/files/lib/Sharing/SourceType/NodeShareSourceType.php

@@ -0,0 +1,35 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+namespace OCA\Files\Sharing\SourceType;
+
+use OCA\Sharing\Model\IShareSourceType;
+use OCP\Files\IRootFolder;
+use OCP\IL10N;
+use OCP\IUser;
+use OCP\Server;
+
+class NodeShareSourceType implements IShareSourceType {
+	public function getDisplayName(): string {
+		return Server::get(IL10N::class)->t('File or folder');
+	}
+
+	public function validateSource(IUser $owner, string $source): bool {
+		return Server::get(IRootFolder::class)->getUserFolder($owner->getUID())->getFirstNodeById((int)$source) !== null;
+	}
+
+	public function getSourceDisplayName(string $source): ?string {
+		$displayName = Server::get(IRootFolder::class)->getFirstNodeById((int)$source)?->getName();
+		if ($displayName === '') {
+			return null;
+		}
+
+		return $displayName;
+	}
+}

apps/files/tests/Controller/ApiControllerTest.php

@@ -36,7 +36,7 @@ use Psr\Log\LoggerInterface;
 use Test\TestCase;
 
 /**
- * Class ApiController
+ * Class ApiV1Controller
  *
  * @package OCA\Files\Controller
  */

apps/files/tests/Sharing/SourceType/NodeShareSourceTypeTest.php

@@ -0,0 +1,76 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+
+use OC\Files\Filesystem;
+use OC\User\Database;
+use OCA\Files\Sharing\SourceType\NodeShareSourceType;
+use OCP\Files\IRootFolder;
+use OCP\IL10N;
+use OCP\IUser;
+use OCP\IUserManager;
+use OCP\L10N\IFactory;
+use OCP\Server;
+use PHPUnit\Framework\Attributes\Group;
+use Test\TestCase;
+
+#[Group(name: 'DB')]
+class NodeShareSourceTypeTest extends TestCase {
+	private IUser $user1;
+
+	private NodeShareSourceType $sourceType;
+
+	public function setUp(): void {
+		parent::setUp();
+
+		$userManager = Server::get(IUserManager::class);
+		$userManager->clearBackends();
+		$userManager->registerBackend(new Database());
+
+		$user1 = $userManager->createUser('user1', 'password');
+		$this->assertNotFalse($user1);
+		$this->user1 = $user1;
+
+		$this->sourceType = new NodeShareSourceType();
+	}
+
+	protected function tearDown(): void {
+		$this->user1->delete();
+
+		Filesystem::tearDown();
+
+		parent::tearDown();
+	}
+
+	public function testGetDisplayName(): void {
+		$this->overwriteService(IL10N::class, Server::get(IFactory::class)->get(''));
+
+		$this->assertEquals('File or folder', $this->sourceType->getDisplayName());
+	}
+
+	public function testValidateSource(): void {
+		$userFolder = Server::get(IRootFolder::class)->getUserFolder($this->user1->getUID());
+		$node = $userFolder->newFile('foo.txt', 'bar');
+		$source = (string)$node->getId();
+
+		$this->assertTrue($this->sourceType->validateSource($this->user1, $source));
+
+		$node->delete();
+
+		$this->assertFalse($this->sourceType->validateSource($this->user1, $source));
+	}
+
+	public function testGetSourceDisplayName(): void {
+		$userFolder = Server::get(IRootFolder::class)->getUserFolder($this->user1->getUID());
+		$node = $userFolder->newFile('foo.txt', 'bar');
+		$source = (string)$node->getId();
+
+		$this->assertEquals('foo.txt', $this->sourceType->getSourceDisplayName($source));
+	}
+}

apps/sharing/appinfo/info.xml

@@ -0,0 +1,27 @@
+<?xml version="1.0"?>
+<!--
+  - SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+  - SPDX-License-Identifier: AGPL-3.0-or-later
+-->
+<info xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	  xsi:noNamespaceSchemaLocation="https://apps.nextcloud.com/schema/apps/info.xsd">
+	<id>sharing</id>
+	<name>Sharing</name>
+	<summary>TODO</summary>
+	<description>TODO</description>
+	<version>1.0.0</version>
+	<licence>AGPL-3.0-or-later</licence>
+	<author>Kate Döen</author>
+	<namespace>Sharing</namespace>
+	<category>customization</category>
+	<bugs>https://github.com/nextcloud/server/issues</bugs>
+	<dependencies>
+		<nextcloud min-version="33" max-version="33"/>
+	</dependencies>
+	<commands>
+		<command>\OCA\Sharing\Command\Create</command>
+		<command>\OCA\Sharing\Command\Delete</command>
+		<command>\OCA\Sharing\Command\Get</command>
+		<command>\OCA\Sharing\Command\Update</command>
+	</commands>
+</info>

apps/sharing/composer/autoload.php

@@ -0,0 +1,22 @@
+<?php
+
+// autoload.php @generated by Composer
+
+if (PHP_VERSION_ID < 50600) {
+    if (!headers_sent()) {
+        header('HTTP/1.1 500 Internal Server Error');
+    }
+    $err = 'Composer 2.3.0 dropped support for autoloading on PHP <5.6 and you are running '.PHP_VERSION.', please upgrade PHP or use Composer 2.2 LTS via "composer self-update --2.2". Aborting.'.PHP_EOL;
+    if (!ini_get('display_errors')) {
+        if (PHP_SAPI === 'cli' || PHP_SAPI === 'phpdbg') {
+            fwrite(STDERR, $err);
+        } elseif (!headers_sent()) {
+            echo $err;
+        }
+    }
+    throw new RuntimeException($err);
+}
+
+require_once __DIR__ . '/composer/autoload_real.php';
+
+return ComposerAutoloaderInitSharing::getLoader();

apps/sharing/composer/composer.json

@@ -0,0 +1,13 @@
+{
+    "config" : {
+        "vendor-dir": ".",
+        "optimize-autoloader": true,
+        "classmap-authoritative": true,
+        "autoloader-suffix": "Sharing"
+    },
+    "autoload" : {
+        "psr-4": {
+            "OCA\\Sharing\\": "../lib/"
+        }
+    }
+}

apps/sharing/composer/composer.lock

@@ -0,0 +1,18 @@
+{
+    "_readme": [
+        "This file locks the dependencies of your project to a known state",
+        "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
+        "This file is @generated automatically"
+    ],
+    "content-hash": "d751713988987e9331980363e24189ce",
+    "packages": [],
+    "packages-dev": [],
+    "aliases": [],
+    "minimum-stability": "stable",
+    "stability-flags": {},
+    "prefer-stable": false,
+    "prefer-lowest": false,
+    "platform": {},
+    "platform-dev": {},
+    "plugin-api-version": "2.6.0"
+}

apps/sharing/composer/composer/ClassLoader.php

@@ -0,0 +1,579 @@
+<?php
+
+/*
+ * This file is part of Composer.
+ *
+ * (c) Nils Adermann <naderman@naderman.de>
+ *     Jordi Boggiano <j.boggiano@seld.be>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Composer\Autoload;
+
+/**
+ * ClassLoader implements a PSR-0, PSR-4 and classmap class loader.
+ *
+ *     $loader = new \Composer\Autoload\ClassLoader();
+ *
+ *     // register classes with namespaces
+ *     $loader->add('Symfony\Component', __DIR__.'/component');
+ *     $loader->add('Symfony',           __DIR__.'/framework');
+ *
+ *     // activate the autoloader
+ *     $loader->register();
+ *
+ *     // to enable searching the include path (eg. for PEAR packages)
+ *     $loader->setUseIncludePath(true);
+ *
+ * In this example, if you try to use a class in the Symfony\Component
+ * namespace or one of its children (Symfony\Component\Console for instance),
+ * the autoloader will first look for the class under the component/
+ * directory, and it will then fallback to the framework/ directory if not
+ * found before giving up.
+ *
+ * This class is loosely based on the Symfony UniversalClassLoader.
+ *
+ * @author Fabien Potencier <fabien@symfony.com>
+ * @author Jordi Boggiano <j.boggiano@seld.be>
+ * @see    https://www.php-fig.org/psr/psr-0/
+ * @see    https://www.php-fig.org/psr/psr-4/
+ */
+class ClassLoader
+{
+    /** @var \Closure(string):void */
+    private static $includeFile;
+
+    /** @var string|null */
+    private $vendorDir;
+
+    // PSR-4
+    /**
+     * @var array<string, array<string, int>>
+     */
+    private $prefixLengthsPsr4 = array();
+    /**
+     * @var array<string, list<string>>
+     */
+    private $prefixDirsPsr4 = array();
+    /**
+     * @var list<string>
+     */
+    private $fallbackDirsPsr4 = array();
+
+    // PSR-0
+    /**
+     * List of PSR-0 prefixes
+     *
+     * Structured as array('F (first letter)' => array('Foo\Bar (full prefix)' => array('path', 'path2')))
+     *
+     * @var array<string, array<string, list<string>>>
+     */
+    private $prefixesPsr0 = array();
+    /**
+     * @var list<string>
+     */
+    private $fallbackDirsPsr0 = array();
+
+    /** @var bool */
+    private $useIncludePath = false;
+
+    /**
+     * @var array<string, string>
+     */
+    private $classMap = array();
+
+    /** @var bool */
+    private $classMapAuthoritative = false;
+
+    /**
+     * @var array<string, bool>
+     */
+    private $missingClasses = array();
+
+    /** @var string|null */
+    private $apcuPrefix;
+
+    /**
+     * @var array<string, self>
+     */
+    private static $registeredLoaders = array();
+
+    /**
+     * @param string|null $vendorDir
+     */
+    public function __construct($vendorDir = null)
+    {
+        $this->vendorDir = $vendorDir;
+        self::initializeIncludeClosure();
+    }
+
+    /**
+     * @return array<string, list<string>>
+     */
+    public function getPrefixes()
+    {
+        if (!empty($this->prefixesPsr0)) {
+            return call_user_func_array('array_merge', array_values($this->prefixesPsr0));
+        }
+
+        return array();
+    }
+
+    /**
+     * @return array<string, list<string>>
+     */
+    public function getPrefixesPsr4()
+    {
+        return $this->prefixDirsPsr4;
+    }
+
+    /**
+     * @return list<string>
+     */
+    public function getFallbackDirs()
+    {
+        return $this->fallbackDirsPsr0;
+    }
+
+    /**
+     * @return list<string>
+     */
+    public function getFallbackDirsPsr4()
+    {
+        return $this->fallbackDirsPsr4;
+    }
+
+    /**
+     * @return array<string, string> Array of classname => path
+     */
+    public function getClassMap()
+    {
+        return $this->classMap;
+    }
+
+    /**
+     * @param array<string, string> $classMap Class to filename map
+     *
+     * @return void
+     */
+    public function addClassMap(array $classMap)
+    {
+        if ($this->classMap) {
+            $this->classMap = array_merge($this->classMap, $classMap);
+        } else {
+            $this->classMap = $classMap;
+        }
+    }
+
+    /**
+     * Registers a set of PSR-0 directories for a given prefix, either
+     * appending or prepending to the ones previously set for this prefix.
+     *
+     * @param string              $prefix  The prefix
+     * @param list<string>|string $paths   The PSR-0 root directories
+     * @param bool                $prepend Whether to prepend the directories
+     *
+     * @return void
+     */
+    public function add($prefix, $paths, $prepend = false)
+    {
+        $paths = (array) $paths;
+        if (!$prefix) {
+            if ($prepend) {
+                $this->fallbackDirsPsr0 = array_merge(
+                    $paths,
+                    $this->fallbackDirsPsr0
+                );
+            } else {
+                $this->fallbackDirsPsr0 = array_merge(
+                    $this->fallbackDirsPsr0,
+                    $paths
+                );
+            }
+
+            return;
+        }
+
+        $first = $prefix[0];
+        if (!isset($this->prefixesPsr0[$first][$prefix])) {
+            $this->prefixesPsr0[$first][$prefix] = $paths;
+
+            return;
+        }
+        if ($prepend) {
+            $this->prefixesPsr0[$first][$prefix] = array_merge(
+                $paths,
+                $this->prefixesPsr0[$first][$prefix]
+            );
+        } else {
+            $this->prefixesPsr0[$first][$prefix] = array_merge(
+                $this->prefixesPsr0[$first][$prefix],
+                $paths
+            );
+        }
+    }
+
+    /**
+     * Registers a set of PSR-4 directories for a given namespace, either
+     * appending or prepending to the ones previously set for this namespace.
+     *
+     * @param string              $prefix  The prefix/namespace, with trailing '\\'
+     * @param list<string>|string $paths   The PSR-4 base directories
+     * @param bool                $prepend Whether to prepend the directories
+     *
+     * @throws \InvalidArgumentException
+     *
+     * @return void
+     */
+    public function addPsr4($prefix, $paths, $prepend = false)
+    {
+        $paths = (array) $paths;
+        if (!$prefix) {
+            // Register directories for the root namespace.
+            if ($prepend) {
+                $this->fallbackDirsPsr4 = array_merge(
+                    $paths,
+                    $this->fallbackDirsPsr4
+                );
+            } else {
+                $this->fallbackDirsPsr4 = array_merge(
+                    $this->fallbackDirsPsr4,
+                    $paths
+                );
+            }
+        } elseif (!isset($this->prefixDirsPsr4[$prefix])) {
+            // Register directories for a new namespace.
+            $length = strlen($prefix);
+            if ('\\' !== $prefix[$length - 1]) {
+                throw new \InvalidArgumentException("A non-empty PSR-4 prefix must end with a namespace separator.");
+            }
+            $this->prefixLengthsPsr4[$prefix[0]][$prefix] = $length;
+            $this->prefixDirsPsr4[$prefix] = $paths;
+        } elseif ($prepend) {
+            // Prepend directories for an already registered namespace.
+            $this->prefixDirsPsr4[$prefix] = array_merge(
+                $paths,
+                $this->prefixDirsPsr4[$prefix]
+            );
+        } else {
+            // Append directories for an already registered namespace.
+            $this->prefixDirsPsr4[$prefix] = array_merge(
+                $this->prefixDirsPsr4[$prefix],
+                $paths
+            );
+        }
+    }
+
+    /**
+     * Registers a set of PSR-0 directories for a given prefix,
+     * replacing any others previously set for this prefix.
+     *
+     * @param string              $prefix The prefix
+     * @param list<string>|string $paths  The PSR-0 base directories
+     *
+     * @return void
+     */
+    public function set($prefix, $paths)
+    {
+        if (!$prefix) {
+            $this->fallbackDirsPsr0 = (array) $paths;
+        } else {
+            $this->prefixesPsr0[$prefix[0]][$prefix] = (array) $paths;
+        }
+    }
+
+    /**
+     * Registers a set of PSR-4 directories for a given namespace,
+     * replacing any others previously set for this namespace.
+     *
+     * @param string              $prefix The prefix/namespace, with trailing '\\'
+     * @param list<string>|string $paths  The PSR-4 base directories
+     *
+     * @throws \InvalidArgumentException
+     *
+     * @return void
+     */
+    public function setPsr4($prefix, $paths)
+    {
+        if (!$prefix) {
+            $this->fallbackDirsPsr4 = (array) $paths;
+        } else {
+            $length = strlen($prefix);
+            if ('\\' !== $prefix[$length - 1]) {
+                throw new \InvalidArgumentException("A non-empty PSR-4 prefix must end with a namespace separator.");
+            }
+            $this->prefixLengthsPsr4[$prefix[0]][$prefix] = $length;
+            $this->prefixDirsPsr4[$prefix] = (array) $paths;
+        }
+    }
+
+    /**
+     * Turns on searching the include path for class files.
+     *
+     * @param bool $useIncludePath
+     *
+     * @return void
+     */
+    public function setUseIncludePath($useIncludePath)
+    {
+        $this->useIncludePath = $useIncludePath;
+    }
+
+    /**
+     * Can be used to check if the autoloader uses the include path to check
+     * for classes.
+     *
+     * @return bool
+     */
+    public function getUseIncludePath()
+    {
+        return $this->useIncludePath;
+    }
+
+    /**
+     * Turns off searching the prefix and fallback directories for classes
+     * that have not been registered with the class map.
+     *
+     * @param bool $classMapAuthoritative
+     *
+     * @return void
+     */
+    public function setClassMapAuthoritative($classMapAuthoritative)
+    {
+        $this->classMapAuthoritative = $classMapAuthoritative;
+    }
+
+    /**
+     * Should class lookup fail if not found in the current class map?
+     *
+     * @return bool
+     */
+    public function isClassMapAuthoritative()
+    {
+        return $this->classMapAuthoritative;
+    }
+
+    /**
+     * APCu prefix to use to cache found/not-found classes, if the extension is enabled.
+     *
+     * @param string|null $apcuPrefix
+     *
+     * @return void
+     */
+    public function setApcuPrefix($apcuPrefix)
+    {
+        $this->apcuPrefix = function_exists('apcu_fetch') && filter_var(ini_get('apc.enabled'), FILTER_VALIDATE_BOOLEAN) ? $apcuPrefix : null;
+    }
+
+    /**
+     * The APCu prefix in use, or null if APCu caching is not enabled.
+     *
+     * @return string|null
+     */
+    public function getApcuPrefix()
+    {
+        return $this->apcuPrefix;
+    }
+
+    /**
+     * Registers this instance as an autoloader.
+     *
+     * @param bool $prepend Whether to prepend the autoloader or not
+     *
+     * @return void
+     */
+    public function register($prepend = false)
+    {
+        spl_autoload_register(array($this, 'loadClass'), true, $prepend);
+
+        if (null === $this->vendorDir) {
+            return;
+        }
+
+        if ($prepend) {
+            self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
+        } else {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+            self::$registeredLoaders[$this->vendorDir] = $this;
+        }
+    }
+
+    /**
+     * Unregisters this instance as an autoloader.
+     *
+     * @return void
+     */
+    public function unregister()
+    {
+        spl_autoload_unregister(array($this, 'loadClass'));
+
+        if (null !== $this->vendorDir) {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+        }
+    }
+
+    /**
+     * Loads the given class or interface.
+     *
+     * @param  string    $class The name of the class
+     * @return true|null True if loaded, null otherwise
+     */
+    public function loadClass($class)
+    {
+        if ($file = $this->findFile($class)) {
+            $includeFile = self::$includeFile;
+            $includeFile($file);
+
+            return true;
+        }
+
+        return null;
+    }
+
+    /**
+     * Finds the path to the file where the class is defined.
+     *
+     * @param string $class The name of the class
+     *
+     * @return string|false The path if found, false otherwise
+     */
+    public function findFile($class)
+    {
+        // class map lookup
+        if (isset($this->classMap[$class])) {
+            return $this->classMap[$class];
+        }
+        if ($this->classMapAuthoritative || isset($this->missingClasses[$class])) {
+            return false;
+        }
+        if (null !== $this->apcuPrefix) {
+            $file = apcu_fetch($this->apcuPrefix.$class, $hit);
+            if ($hit) {
+                return $file;
+            }
+        }
+
+        $file = $this->findFileWithExtension($class, '.php');
+
+        // Search for Hack files if we are running on HHVM
+        if (false === $file && defined('HHVM_VERSION')) {
+            $file = $this->findFileWithExtension($class, '.hh');
+        }
+
+        if (null !== $this->apcuPrefix) {
+            apcu_add($this->apcuPrefix.$class, $file);
+        }
+
+        if (false === $file) {
+            // Remember that this class does not exist.
+            $this->missingClasses[$class] = true;
+        }
+
+        return $file;
+    }
+
+    /**
+     * Returns the currently registered loaders keyed by their corresponding vendor directories.
+     *
+     * @return array<string, self>
+     */
+    public static function getRegisteredLoaders()
+    {
+        return self::$registeredLoaders;
+    }
+
+    /**
+     * @param  string       $class
+     * @param  string       $ext
+     * @return string|false
+     */
+    private function findFileWithExtension($class, $ext)
+    {
+        // PSR-4 lookup
+        $logicalPathPsr4 = strtr($class, '\\', DIRECTORY_SEPARATOR) . $ext;
+
+        $first = $class[0];
+        if (isset($this->prefixLengthsPsr4[$first])) {
+            $subPath = $class;
+            while (false !== $lastPos = strrpos($subPath, '\\')) {
+                $subPath = substr($subPath, 0, $lastPos);
+                $search = $subPath . '\\';
+                if (isset($this->prefixDirsPsr4[$search])) {
+                    $pathEnd = DIRECTORY_SEPARATOR . substr($logicalPathPsr4, $lastPos + 1);
+                    foreach ($this->prefixDirsPsr4[$search] as $dir) {
+                        if (file_exists($file = $dir . $pathEnd)) {
+                            return $file;
+                        }
+                    }
+                }
+            }
+        }
+
+        // PSR-4 fallback dirs
+        foreach ($this->fallbackDirsPsr4 as $dir) {
+            if (file_exists($file = $dir . DIRECTORY_SEPARATOR . $logicalPathPsr4)) {
+                return $file;
+            }
+        }
+
+        // PSR-0 lookup
+        if (false !== $pos = strrpos($class, '\\')) {
+            // namespaced class name
+            $logicalPathPsr0 = substr($logicalPathPsr4, 0, $pos + 1)
+                . strtr(substr($logicalPathPsr4, $pos + 1), '_', DIRECTORY_SEPARATOR);
+        } else {
+            // PEAR-like class name
+            $logicalPathPsr0 = strtr($class, '_', DIRECTORY_SEPARATOR) . $ext;
+        }
+
+        if (isset($this->prefixesPsr0[$first])) {
+            foreach ($this->prefixesPsr0[$first] as $prefix => $dirs) {
+                if (0 === strpos($class, $prefix)) {
+                    foreach ($dirs as $dir) {
+                        if (file_exists($file = $dir . DIRECTORY_SEPARATOR . $logicalPathPsr0)) {
+                            return $file;
+                        }
+                    }
+                }
+            }
+        }
+
+        // PSR-0 fallback dirs
+        foreach ($this->fallbackDirsPsr0 as $dir) {
+            if (file_exists($file = $dir . DIRECTORY_SEPARATOR . $logicalPathPsr0)) {
+                return $file;
+            }
+        }
+
+        // PSR-0 include paths.
+        if ($this->useIncludePath && $file = stream_resolve_include_path($logicalPathPsr0)) {
+            return $file;
+        }
+
+        return false;
+    }
+
+    /**
+     * @return void
+     */
+    private static function initializeIncludeClosure()
+    {
+        if (self::$includeFile !== null) {
+            return;
+        }
+
+        /**
+         * Scope isolated include.
+         *
+         * Prevents access to $this/self from included files.
+         *
+         * @param  string $file
+         * @return void
+         */
+        self::$includeFile = \Closure::bind(static function($file) {
+            include $file;
+        }, null, null);
+    }
+}

apps/sharing/composer/composer/InstalledVersions.php

@@ -0,0 +1,396 @@
+<?php
+
+/*
+ * This file is part of Composer.
+ *
+ * (c) Nils Adermann <naderman@naderman.de>
+ *     Jordi Boggiano <j.boggiano@seld.be>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Composer;
+
+use Composer\Autoload\ClassLoader;
+use Composer\Semver\VersionParser;
+
+/**
+ * This class is copied in every Composer installed project and available to all
+ *
+ * See also https://getcomposer.org/doc/07-runtime.md#installed-versions
+ *
+ * To require its presence, you can require `composer-runtime-api ^2.0`
+ *
+ * @final
+ */
+class InstalledVersions
+{
+    /**
+     * @var string|null if set (by reflection by Composer), this should be set to the path where this class is being copied to
+     * @internal
+     */
+    private static $selfDir = null;
+
+    /**
+     * @var mixed[]|null
+     * @psalm-var array{root: array{name: string, pretty_version: string, version: string, reference: string|null, type: string, install_path: string, aliases: string[], dev: bool}, versions: array<string, array{pretty_version?: string, version?: string, reference?: string|null, type?: string, install_path?: string, aliases?: string[], dev_requirement: bool, replaced?: string[], provided?: string[]}>}|array{}|null
+     */
+    private static $installed;
+
+    /**
+     * @var bool
+     */
+    private static $installedIsLocalDir;
+
+    /**
+     * @var bool|null
+     */
+    private static $canGetVendors;
+
+    /**
+     * @var array[]
+     * @psalm-var array<string, array{root: array{name: string, pretty_version: string, version: string, reference: string|null, type: string, install_path: string, aliases: string[], dev: bool}, versions: array<string, array{pretty_version?: string, version?: string, reference?: string|null, type?: string, install_path?: string, aliases?: string[], dev_requirement: bool, replaced?: string[], provided?: string[]}>}>
+     */
+    private static $installedByVendor = array();
+
+    /**
+     * Returns a list of all package names which are present, either by being installed, replaced or provided
+     *
+     * @return string[]
+     * @psalm-return list<string>
+     */
+    public static function getInstalledPackages()
+    {
+        $packages = array();
+        foreach (self::getInstalled() as $installed) {
+            $packages[] = array_keys($installed['versions']);
+        }
+
+        if (1 === \count($packages)) {
+            return $packages[0];
+        }
+
+        return array_keys(array_flip(\call_user_func_array('array_merge', $packages)));
+    }
+
+    /**
+     * Returns a list of all package names with a specific type e.g. 'library'
+     *
+     * @param  string   $type
+     * @return string[]
+     * @psalm-return list<string>
+     */
+    public static function getInstalledPackagesByType($type)
+    {
+        $packagesByType = array();
+
+        foreach (self::getInstalled() as $installed) {
+            foreach ($installed['versions'] as $name => $package) {
+                if (isset($package['type']) && $package['type'] === $type) {
+                    $packagesByType[] = $name;
+                }
+            }
+        }
+
+        return $packagesByType;
+    }
+
+    /**
+     * Checks whether the given package is installed
+     *
+     * This also returns true if the package name is provided or replaced by another package
+     *
+     * @param  string $packageName
+     * @param  bool   $includeDevRequirements
+     * @return bool
+     */
+    public static function isInstalled($packageName, $includeDevRequirements = true)
+    {
+        foreach (self::getInstalled() as $installed) {
+            if (isset($installed['versions'][$packageName])) {
+                return $includeDevRequirements || !isset($installed['versions'][$packageName]['dev_requirement']) || $installed['versions'][$packageName]['dev_requirement'] === false;
+            }
+        }
+
+        return false;
+    }
+
+    /**
+     * Checks whether the given package satisfies a version constraint
+     *
+     * e.g. If you want to know whether version 2.3+ of package foo/bar is installed, you would call:
+     *
+     *   Composer\InstalledVersions::satisfies(new VersionParser, 'foo/bar', '^2.3')
+     *
+     * @param  VersionParser $parser      Install composer/semver to have access to this class and functionality
+     * @param  string        $packageName
+     * @param  string|null   $constraint  A version constraint to check for, if you pass one you have to make sure composer/semver is required by your package
+     * @return bool
+     */
+    public static function satisfies(VersionParser $parser, $packageName, $constraint)
+    {
+        $constraint = $parser->parseConstraints((string) $constraint);
+        $provided = $parser->parseConstraints(self::getVersionRanges($packageName));
+
+        return $provided->matches($constraint);
+    }
+
+    /**
+     * Returns a version constraint representing all the range(s) which are installed for a given package
+     *
+     * It is easier to use this via isInstalled() with the $constraint argument if you need to check
+     * whether a given version of a package is installed, and not just whether it exists
+     *
+     * @param  string $packageName
+     * @return string Version constraint usable with composer/semver
+     */
+    public static function getVersionRanges($packageName)
+    {
+        foreach (self::getInstalled() as $installed) {
+            if (!isset($installed['versions'][$packageName])) {
+                continue;
+            }
+
+            $ranges = array();
+            if (isset($installed['versions'][$packageName]['pretty_version'])) {
+                $ranges[] = $installed['versions'][$packageName]['pretty_version'];
+            }
+            if (array_key_exists('aliases', $installed['versions'][$packageName])) {
+                $ranges = array_merge($ranges, $installed['versions'][$packageName]['aliases']);
+            }
+            if (array_key_exists('replaced', $installed['versions'][$packageName])) {
+                $ranges = array_merge($ranges, $installed['versions'][$packageName]['replaced']);
+            }
+            if (array_key_exists('provided', $installed['versions'][$packageName])) {
+                $ranges = array_merge($ranges, $installed['versions'][$packageName]['provided']);
+            }
+
+            return implode(' || ', $ranges);
+        }
+
+        throw new \OutOfBoundsException('Package "' . $packageName . '" is not installed');
+    }
+
+    /**
+     * @param  string      $packageName
+     * @return string|null If the package is being replaced or provided but is not really installed, null will be returned as version, use satisfies or getVersionRanges if you need to know if a given version is present
+     */
+    public static function getVersion($packageName)
+    {
+        foreach (self::getInstalled() as $installed) {
+            if (!isset($installed['versions'][$packageName])) {
+                continue;
+            }
+
+            if (!isset($installed['versions'][$packageName]['version'])) {
+                return null;
+            }
+
+            return $installed['versions'][$packageName]['version'];
+        }
+
+        throw new \OutOfBoundsException('Package "' . $packageName . '" is not installed');
+    }
+
+    /**
+     * @param  string      $packageName
+     * @return string|null If the package is being replaced or provided but is not really installed, null will be returned as version, use satisfies or getVersionRanges if you need to know if a given version is present
+     */
+    public static function getPrettyVersion($packageName)
+    {
+        foreach (self::getInstalled() as $installed) {
+            if (!isset($installed['versions'][$packageName])) {
+                continue;
+            }
+
+            if (!isset($installed['versions'][$packageName]['pretty_version'])) {
+                return null;
+            }
+
+            return $installed['versions'][$packageName]['pretty_version'];
+        }
+
+        throw new \OutOfBoundsException('Package "' . $packageName . '" is not installed');
+    }
+
+    /**
+     * @param  string      $packageName
+     * @return string|null If the package is being replaced or provided but is not really installed, null will be returned as reference
+     */
+    public static function getReference($packageName)
+    {
+        foreach (self::getInstalled() as $installed) {
+            if (!isset($installed['versions'][$packageName])) {
+                continue;
+            }
+
+            if (!isset($installed['versions'][$packageName]['reference'])) {
+                return null;
+            }
+
+            return $installed['versions'][$packageName]['reference'];
+        }
+
+        throw new \OutOfBoundsException('Package "' . $packageName . '" is not installed');
+    }
+
+    /**
+     * @param  string      $packageName
+     * @return string|null If the package is being replaced or provided but is not really installed, null will be returned as install path. Packages of type metapackages also have a null install path.
+     */
+    public static function getInstallPath($packageName)
+    {
+        foreach (self::getInstalled() as $installed) {
+            if (!isset($installed['versions'][$packageName])) {
+                continue;
+            }
+
+            return isset($installed['versions'][$packageName]['install_path']) ? $installed['versions'][$packageName]['install_path'] : null;
+        }
+
+        throw new \OutOfBoundsException('Package "' . $packageName . '" is not installed');
+    }
+
+    /**
+     * @return array
+     * @psalm-return array{name: string, pretty_version: string, version: string, reference: string|null, type: string, install_path: string, aliases: string[], dev: bool}
+     */
+    public static function getRootPackage()
+    {
+        $installed = self::getInstalled();
+
+        return $installed[0]['root'];
+    }
+
+    /**
+     * Returns the raw installed.php data for custom implementations
+     *
+     * @deprecated Use getAllRawData() instead which returns all datasets for all autoloaders present in the process. getRawData only returns the first dataset loaded, which may not be what you expect.
+     * @return array[]
+     * @psalm-return array{root: array{name: string, pretty_version: string, version: string, reference: string|null, type: string, install_path: string, aliases: string[], dev: bool}, versions: array<string, array{pretty_version?: string, version?: string, reference?: string|null, type?: string, install_path?: string, aliases?: string[], dev_requirement: bool, replaced?: string[], provided?: string[]}>}
+     */
+    public static function getRawData()
+    {
+        @trigger_error('getRawData only returns the first dataset loaded, which may not be what you expect. Use getAllRawData() instead which returns all datasets for all autoloaders present in the process.', E_USER_DEPRECATED);
+
+        if (null === self::$installed) {
+            // only require the installed.php file if this file is loaded from its dumped location,
+            // and not from its source location in the composer/composer package, see https://github.com/composer/composer/issues/9937
+            if (substr(__DIR__, -8, 1) !== 'C') {
+                self::$installed = include __DIR__ . '/installed.php';
+            } else {
+                self::$installed = array();
+            }
+        }
+
+        return self::$installed;
+    }
+
+    /**
+     * Returns the raw data of all installed.php which are currently loaded for custom implementations
+     *
+     * @return array[]
+     * @psalm-return list<array{root: array{name: string, pretty_version: string, version: string, reference: string|null, type: string, install_path: string, aliases: string[], dev: bool}, versions: array<string, array{pretty_version?: string, version?: string, reference?: string|null, type?: string, install_path?: string, aliases?: string[], dev_requirement: bool, replaced?: string[], provided?: string[]}>}>
+     */
+    public static function getAllRawData()
+    {
+        return self::getInstalled();
+    }
+
+    /**
+     * Lets you reload the static array from another file
+     *
+     * This is only useful for complex integrations in which a project needs to use
+     * this class but then also needs to execute another project's autoloader in process,
+     * and wants to ensure both projects have access to their version of installed.php.
+     *
+     * A typical case would be PHPUnit, where it would need to make sure it reads all
+     * the data it needs from this class, then call reload() with
+     * `require $CWD/vendor/composer/installed.php` (or similar) as input to make sure
+     * the project in which it runs can then also use this class safely, without
+     * interference between PHPUnit's dependencies and the project's dependencies.
+     *
+     * @param  array[] $data A vendor/composer/installed.php data set
+     * @return void
+     *
+     * @psalm-param array{root: array{name: string, pretty_version: string, version: string, reference: string|null, type: string, install_path: string, aliases: string[], dev: bool}, versions: array<string, array{pretty_version?: string, version?: string, reference?: string|null, type?: string, install_path?: string, aliases?: string[], dev_requirement: bool, replaced?: string[], provided?: string[]}>} $data
+     */
+    public static function reload($data)
+    {
+        self::$installed = $data;
+        self::$installedByVendor = array();
+
+        // when using reload, we disable the duplicate protection to ensure that self::$installed data is
+        // always returned, but we cannot know whether it comes from the installed.php in __DIR__ or not,
+        // so we have to assume it does not, and that may result in duplicate data being returned when listing
+        // all installed packages for example
+        self::$installedIsLocalDir = false;
+    }
+
+    /**
+     * @return string
+     */
+    private static function getSelfDir()
+    {
+        if (self::$selfDir === null) {
+            self::$selfDir = strtr(__DIR__, '\\', '/');
+        }
+
+        return self::$selfDir;
+    }
+
+    /**
+     * @return array[]
+     * @psalm-return list<array{root: array{name: string, pretty_version: string, version: string, reference: string|null, type: string, install_path: string, aliases: string[], dev: bool}, versions: array<string, array{pretty_version?: string, version?: string, reference?: string|null, type?: string, install_path?: string, aliases?: string[], dev_requirement: bool, replaced?: string[], provided?: string[]}>}>
+     */
+    private static function getInstalled()
+    {
+        if (null === self::$canGetVendors) {
+            self::$canGetVendors = method_exists('Composer\Autoload\ClassLoader', 'getRegisteredLoaders');
+        }
+
+        $installed = array();
+        $copiedLocalDir = false;
+
+        if (self::$canGetVendors) {
+            $selfDir = self::getSelfDir();
+            foreach (ClassLoader::getRegisteredLoaders() as $vendorDir => $loader) {
+                $vendorDir = strtr($vendorDir, '\\', '/');
+                if (isset(self::$installedByVendor[$vendorDir])) {
+                    $installed[] = self::$installedByVendor[$vendorDir];
+                } elseif (is_file($vendorDir.'/composer/installed.php')) {
+                    /** @var array{root: array{name: string, pretty_version: string, version: string, reference: string|null, type: string, install_path: string, aliases: string[], dev: bool}, versions: array<string, array{pretty_version?: string, version?: string, reference?: string|null, type?: string, install_path?: string, aliases?: string[], dev_requirement: bool, replaced?: string[], provided?: string[]}>} $required */
+                    $required = require $vendorDir.'/composer/installed.php';
+                    self::$installedByVendor[$vendorDir] = $required;
+                    $installed[] = $required;
+                    if (self::$installed === null && $vendorDir.'/composer' === $selfDir) {
+                        self::$installed = $required;
+                        self::$installedIsLocalDir = true;
+                    }
+                }
+                if (self::$installedIsLocalDir && $vendorDir.'/composer' === $selfDir) {
+                    $copiedLocalDir = true;
+                }
+            }
+        }
+
+        if (null === self::$installed) {
+            // only require the installed.php file if this file is loaded from its dumped location,
+            // and not from its source location in the composer/composer package, see https://github.com/composer/composer/issues/9937
+            if (substr(__DIR__, -8, 1) !== 'C') {
+                /** @var array{root: array{name: string, pretty_version: string, version: string, reference: string|null, type: string, install_path: string, aliases: string[], dev: bool}, versions: array<string, array{pretty_version?: string, version?: string, reference?: string|null, type?: string, install_path?: string, aliases?: string[], dev_requirement: bool, replaced?: string[], provided?: string[]}>} $required */
+                $required = require __DIR__ . '/installed.php';
+                self::$installed = $required;
+            } else {
+                self::$installed = array();
+            }
+        }
+
+        if (self::$installed !== array() && !$copiedLocalDir) {
+            $installed[] = self::$installed;
+        }
+
+        return $installed;
+    }
+}

apps/sharing/composer/composer/LICENSE

@@ -0,0 +1,21 @@
+
+Copyright (c) Nils Adermann, Jordi Boggiano
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is furnished
+to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+

apps/sharing/composer/composer/autoload_classmap.php

@@ -0,0 +1,40 @@
+<?php
+
+// autoload_classmap.php @generated by Composer
+
+$vendorDir = dirname(__DIR__);
+$baseDir = $vendorDir;
+
+return array(
+    'Composer\\InstalledVersions' => $vendorDir . '/composer/InstalledVersions.php',
+    'OCA\\Sharing\\AppInfo\\Application' => $baseDir . '/../lib/AppInfo/Application.php',
+    'OCA\\Sharing\\Capabilities' => $baseDir . '/../lib/Capabilities.php',
+    'OCA\\Sharing\\Command\\Create' => $baseDir . '/../lib/Command/Create.php',
+    'OCA\\Sharing\\Command\\Delete' => $baseDir . '/../lib/Command/Delete.php',
+    'OCA\\Sharing\\Command\\Get' => $baseDir . '/../lib/Command/Get.php',
+    'OCA\\Sharing\\Command\\Update' => $baseDir . '/../lib/Command/Update.php',
+    'OCA\\Sharing\\Controller\\ApiV1Controller' => $baseDir . '/../lib/Controller/ApiV1Controller.php',
+    'OCA\\Sharing\\Exception\\AShareException' => $baseDir . '/../lib/Exception/AShareException.php',
+    'OCA\\Sharing\\Exception\\ShareConflictException' => $baseDir . '/../lib/Exception/ShareConflictException.php',
+    'OCA\\Sharing\\Exception\\ShareInvalidException' => $baseDir . '/../lib/Exception/ShareInvalidException.php',
+    'OCA\\Sharing\\Exception\\ShareInvalidOperationParameterException' => $baseDir . '/../lib/Exception/ShareInvalidOperationParameterException.php',
+    'OCA\\Sharing\\Exception\\ShareInvalidPropertiesException' => $baseDir . '/../lib/Exception/ShareInvalidPropertiesException.php',
+    'OCA\\Sharing\\Exception\\ShareNotFoundException' => $baseDir . '/../lib/Exception/ShareNotFoundException.php',
+    'OCA\\Sharing\\Exception\\ShareOperationNotAllowedException' => $baseDir . '/../lib/Exception/ShareOperationNotAllowedException.php',
+    'OCA\\Sharing\\Manager' => $baseDir . '/../lib/Manager.php',
+    'OCA\\Sharing\\Migration\\Version1000Date20250929161325' => $baseDir . '/../lib/Migration/Version1000Date20250929161325.php',
+    'OCA\\Sharing\\Model\\IShareFeature' => $baseDir . '/../lib/Model/IShareFeature.php',
+    'OCA\\Sharing\\Model\\IShareFeatureFilter' => $baseDir . '/../lib/Model/IShareFeatureFilter.php',
+    'OCA\\Sharing\\Model\\IShareFeatureModifyProperties' => $baseDir . '/../lib/Model/IShareFeatureModifyProperties.php',
+    'OCA\\Sharing\\Model\\IShareRecipientType' => $baseDir . '/../lib/Model/IShareRecipientType.php',
+    'OCA\\Sharing\\Model\\IShareRecipientTypeSearch' => $baseDir . '/../lib/Model/IShareRecipientTypeSearch.php',
+    'OCA\\Sharing\\Model\\IShareSourceType' => $baseDir . '/../lib/Model/IShareSourceType.php',
+    'OCA\\Sharing\\Model\\Share' => $baseDir . '/../lib/Model/Share.php',
+    'OCA\\Sharing\\Model\\ShareAccessContext' => $baseDir . '/../lib/Model/ShareAccessContext.php',
+    'OCA\\Sharing\\Model\\ShareOwner' => $baseDir . '/../lib/Model/ShareOwner.php',
+    'OCA\\Sharing\\Model\\ShareRecipient' => $baseDir . '/../lib/Model/ShareRecipient.php',
+    'OCA\\Sharing\\Model\\ShareRecipientSearchResult' => $baseDir . '/../lib/Model/ShareRecipientSearchResult.php',
+    'OCA\\Sharing\\Model\\ShareSource' => $baseDir . '/../lib/Model/ShareSource.php',
+    'OCA\\Sharing\\Registry' => $baseDir . '/../lib/Registry.php',
+    'OCA\\Sharing\\ResponseDefinitions' => $baseDir . '/../lib/ResponseDefinitions.php',
+);

apps/sharing/composer/composer/autoload_namespaces.php

@@ -0,0 +1,9 @@
+<?php
+
+// autoload_namespaces.php @generated by Composer
+
+$vendorDir = dirname(__DIR__);
+$baseDir = $vendorDir;
+
+return array(
+);

apps/sharing/composer/composer/autoload_psr4.php

@@ -0,0 +1,10 @@
+<?php
+
+// autoload_psr4.php @generated by Composer
+
+$vendorDir = dirname(__DIR__);
+$baseDir = $vendorDir;
+
+return array(
+    'OCA\\Sharing\\' => array($baseDir . '/../lib'),
+);

apps/sharing/composer/composer/autoload_real.php

@@ -0,0 +1,37 @@
+<?php
+
+// autoload_real.php @generated by Composer
+
+class ComposerAutoloaderInitSharing
+{
+    private static $loader;
+
+    public static function loadClassLoader($class)
+    {
+        if ('Composer\Autoload\ClassLoader' === $class) {
+            require __DIR__ . '/ClassLoader.php';
+        }
+    }
+
+    /**
+     * @return \Composer\Autoload\ClassLoader
+     */
+    public static function getLoader()
+    {
+        if (null !== self::$loader) {
+            return self::$loader;
+        }
+
+        spl_autoload_register(array('ComposerAutoloaderInitSharing', 'loadClassLoader'), true, true);
+        self::$loader = $loader = new \Composer\Autoload\ClassLoader(\dirname(__DIR__));
+        spl_autoload_unregister(array('ComposerAutoloaderInitSharing', 'loadClassLoader'));
+
+        require __DIR__ . '/autoload_static.php';
+        call_user_func(\Composer\Autoload\ComposerStaticInitSharing::getInitializer($loader));
+
+        $loader->setClassMapAuthoritative(true);
+        $loader->register(true);
+
+        return $loader;
+    }
+}

apps/sharing/composer/composer/autoload_static.php

@@ -0,0 +1,66 @@
+<?php
+
+// autoload_static.php @generated by Composer
+
+namespace Composer\Autoload;
+
+class ComposerStaticInitSharing
+{
+    public static $prefixLengthsPsr4 = array (
+        'O' =>
+        array (
+            'OCA\\Sharing\\' => 12,
+        ),
+    );
+
+    public static $prefixDirsPsr4 = array (
+        'OCA\\Sharing\\' =>
+        array (
+            0 => __DIR__ . '/..' . '/../lib',
+        ),
+    );
+
+    public static $classMap = array (
+        'Composer\\InstalledVersions' => __DIR__ . '/..' . '/composer/InstalledVersions.php',
+        'OCA\\Sharing\\AppInfo\\Application' => __DIR__ . '/..' . '/../lib/AppInfo/Application.php',
+        'OCA\\Sharing\\Capabilities' => __DIR__ . '/..' . '/../lib/Capabilities.php',
+        'OCA\\Sharing\\Command\\Create' => __DIR__ . '/..' . '/../lib/Command/Create.php',
+        'OCA\\Sharing\\Command\\Delete' => __DIR__ . '/..' . '/../lib/Command/Delete.php',
+        'OCA\\Sharing\\Command\\Get' => __DIR__ . '/..' . '/../lib/Command/Get.php',
+        'OCA\\Sharing\\Command\\Update' => __DIR__ . '/..' . '/../lib/Command/Update.php',
+        'OCA\\Sharing\\Controller\\ApiV1Controller' => __DIR__ . '/..' . '/../lib/Controller/ApiV1Controller.php',
+        'OCA\\Sharing\\Exception\\AShareException' => __DIR__ . '/..' . '/../lib/Exception/AShareException.php',
+        'OCA\\Sharing\\Exception\\ShareConflictException' => __DIR__ . '/..' . '/../lib/Exception/ShareConflictException.php',
+        'OCA\\Sharing\\Exception\\ShareInvalidException' => __DIR__ . '/..' . '/../lib/Exception/ShareInvalidException.php',
+        'OCA\\Sharing\\Exception\\ShareInvalidOperationParameterException' => __DIR__ . '/..' . '/../lib/Exception/ShareInvalidOperationParameterException.php',
+        'OCA\\Sharing\\Exception\\ShareInvalidPropertiesException' => __DIR__ . '/..' . '/../lib/Exception/ShareInvalidPropertiesException.php',
+        'OCA\\Sharing\\Exception\\ShareNotFoundException' => __DIR__ . '/..' . '/../lib/Exception/ShareNotFoundException.php',
+        'OCA\\Sharing\\Exception\\ShareOperationNotAllowedException' => __DIR__ . '/..' . '/../lib/Exception/ShareOperationNotAllowedException.php',
+        'OCA\\Sharing\\Manager' => __DIR__ . '/..' . '/../lib/Manager.php',
+        'OCA\\Sharing\\Migration\\Version1000Date20250929161325' => __DIR__ . '/..' . '/../lib/Migration/Version1000Date20250929161325.php',
+        'OCA\\Sharing\\Model\\IShareFeature' => __DIR__ . '/..' . '/../lib/Model/IShareFeature.php',
+        'OCA\\Sharing\\Model\\IShareFeatureFilter' => __DIR__ . '/..' . '/../lib/Model/IShareFeatureFilter.php',
+        'OCA\\Sharing\\Model\\IShareFeatureModifyProperties' => __DIR__ . '/..' . '/../lib/Model/IShareFeatureModifyProperties.php',
+        'OCA\\Sharing\\Model\\IShareRecipientType' => __DIR__ . '/..' . '/../lib/Model/IShareRecipientType.php',
+        'OCA\\Sharing\\Model\\IShareRecipientTypeSearch' => __DIR__ . '/..' . '/../lib/Model/IShareRecipientTypeSearch.php',
+        'OCA\\Sharing\\Model\\IShareSourceType' => __DIR__ . '/..' . '/../lib/Model/IShareSourceType.php',
+        'OCA\\Sharing\\Model\\Share' => __DIR__ . '/..' . '/../lib/Model/Share.php',
+        'OCA\\Sharing\\Model\\ShareAccessContext' => __DIR__ . '/..' . '/../lib/Model/ShareAccessContext.php',
+        'OCA\\Sharing\\Model\\ShareOwner' => __DIR__ . '/..' . '/../lib/Model/ShareOwner.php',
+        'OCA\\Sharing\\Model\\ShareRecipient' => __DIR__ . '/..' . '/../lib/Model/ShareRecipient.php',
+        'OCA\\Sharing\\Model\\ShareRecipientSearchResult' => __DIR__ . '/..' . '/../lib/Model/ShareRecipientSearchResult.php',
+        'OCA\\Sharing\\Model\\ShareSource' => __DIR__ . '/..' . '/../lib/Model/ShareSource.php',
+        'OCA\\Sharing\\Registry' => __DIR__ . '/..' . '/../lib/Registry.php',
+        'OCA\\Sharing\\ResponseDefinitions' => __DIR__ . '/..' . '/../lib/ResponseDefinitions.php',
+    );
+
+    public static function getInitializer(ClassLoader $loader)
+    {
+        return \Closure::bind(function () use ($loader) {
+            $loader->prefixLengthsPsr4 = ComposerStaticInitSharing::$prefixLengthsPsr4;
+            $loader->prefixDirsPsr4 = ComposerStaticInitSharing::$prefixDirsPsr4;
+            $loader->classMap = ComposerStaticInitSharing::$classMap;
+
+        }, null, ClassLoader::class);
+    }
+}

apps/sharing/composer/composer/installed.json

@@ -0,0 +1,5 @@
+{
+    "packages": [],
+    "dev": false,
+    "dev-package-names": []
+}

apps/sharing/composer/composer/installed.php

@@ -0,0 +1,23 @@
+<?php return array(
+    'root' => array(
+        'name' => '__root__',
+        'pretty_version' => 'dev-master',
+        'version' => 'dev-master',
+        'reference' => '80e46b06f38dbb04b413d427a75ef60eb5b29e18',
+        'type' => 'library',
+        'install_path' => __DIR__ . '/../',
+        'aliases' => array(),
+        'dev' => false,
+    ),
+    'versions' => array(
+        '__root__' => array(
+            'pretty_version' => 'dev-master',
+            'version' => 'dev-master',
+            'reference' => '80e46b06f38dbb04b413d427a75ef60eb5b29e18',
+            'type' => 'library',
+            'install_path' => __DIR__ . '/../',
+            'aliases' => array(),
+            'dev_requirement' => false,
+        ),
+    ),
+);

apps/sharing/lib/AppInfo/Application.php

@@ -0,0 +1,31 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+namespace OCA\Sharing\AppInfo;
+
+use OCA\Sharing\Capabilities;
+use OCP\AppFramework\App;
+use OCP\AppFramework\Bootstrap\IBootContext;
+use OCP\AppFramework\Bootstrap\IBootstrap;
+use OCP\AppFramework\Bootstrap\IRegistrationContext;
+
+class Application extends App implements IBootstrap {
+	public const APP_ID = 'sharing';
+
+	public function __construct(array $urlParams = []) {
+		parent::__construct(self::APP_ID, $urlParams);
+	}
+
+	public function register(IRegistrationContext $context): void {
+		$context->registerCapability(Capabilities::class);
+	}
+
+	public function boot(IBootContext $context): void {
+	}
+}

apps/sharing/lib/Capabilities.php

@@ -0,0 +1,49 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+namespace OCA\Sharing;
+
+use OCA\Sharing\AppInfo\Application;
+use OCA\Sharing\Model\IShareFeature;
+use OCA\Sharing\Model\IShareRecipientType;
+use OCA\Sharing\Model\IShareSourceType;
+use OCP\Capabilities\ICapability;
+
+/**
+ * @psalm-import-type SharingFeature from ResponseDefinitions
+ */
+class Capabilities implements ICapability {
+	public function __construct(
+		private readonly Registry $registry,
+	) {
+	}
+
+	/**
+	 * @return array{
+	 *     sharing: array{
+	 *         api_versions: list<'v1'>,
+	 *         source_types: array<class-string<IShareSourceType>, non-empty-string>,
+	 *         recipient_types: array<class-string<IShareRecipientType>, non-empty-string>,
+	 *         features: array<class-string<IShareFeature>, SharingFeature>,
+	 *     },
+	 * }
+	 */
+	public function getCapabilities(): array {
+		return [
+			Application::APP_ID => [
+				'api_versions' => ['v1'],
+				'source_types' => array_map(static fn (IShareSourceType $sourceType): string => $sourceType->getDisplayName(), $this->registry->getSourceTypes()),
+				'recipient_types' => array_map(static fn (IShareRecipientType $recipientType): string => $recipientType->getDisplayName(), $this->registry->getRecipientTypes()),
+				'features' => array_map(static fn (IShareFeature $feature): array => [
+					'compatibles' => $feature->getCompatibles(),
+				], $this->registry->getFeatures()),
+			],
+		];
+	}
+}

apps/sharing/lib/Command/Create.php

@@ -0,0 +1,54 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+namespace OCA\Sharing\Command;
+
+use OCA\Sharing\Exception\AShareException;
+use OCA\Sharing\Manager;
+use OCA\Sharing\Model\Share;
+use OCA\Sharing\Model\ShareAccessContext;
+use OCA\Sharing\ResponseDefinitions;
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Input\InputArgument;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Output\OutputInterface;
+
+/**
+ * @psalm-import-type SharingPartialShare from ResponseDefinitions
+ */
+class Create extends Command {
+	public function __construct(
+		private readonly Manager $manager,
+	) {
+		parent::__construct();
+	}
+
+	protected function configure(): void {
+		$this
+			->setName('share:create')
+			->setDescription('create a new share')
+			->addArgument('data', InputArgument::REQUIRED, 'Share data');
+	}
+
+	public function execute(InputInterface $input, OutputInterface $output): int {
+		/** @var SharingPartialShare $data */
+		$data = json_decode((string)$input->getArgument('data'), true, 512, JSON_THROW_ON_ERROR);
+		$share = Share::fromArray($this->manager->completePartialShareData($data));
+
+		try {
+			$this->manager->insert($share);
+			$output->writeln(json_encode($this->manager->get(new ShareAccessContext(force: true), $share->id)->toArray(), JSON_THROW_ON_ERROR));
+		} catch (AShareException $aShareException) {
+			$output->writeln($aShareException->getMessage());
+			return 1;
+		}
+
+		return 0;
+	}
+}

apps/sharing/lib/Command/Delete.php

@@ -0,0 +1,46 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+namespace OCA\Sharing\Command;
+
+use OCA\Sharing\Exception\AShareException;
+use OCA\Sharing\Manager;
+use OCA\Sharing\Model\ShareAccessContext;
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Input\InputArgument;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Output\OutputInterface;
+
+class Delete extends Command {
+	public function __construct(
+		private readonly Manager $manager,
+	) {
+		parent::__construct();
+	}
+
+	protected function configure(): void {
+		$this
+			->setName('share:delete')
+			->setDescription('delete an existing share')
+			->addArgument('id', InputArgument::REQUIRED, 'Share ID');
+	}
+
+	public function execute(InputInterface $input, OutputInterface $output): int {
+		$id = (string)$input->getArgument('id');
+
+		try {
+			$this->manager->delete(new ShareAccessContext(force: true), $id);
+		} catch (AShareException $aShareException) {
+			$output->writeln($aShareException->getMessage());
+			return 1;
+		}
+
+		return 0;
+	}
+}

apps/sharing/lib/Command/Get.php

@@ -0,0 +1,47 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+namespace OCA\Sharing\Command;
+
+use OCA\Sharing\Exception\AShareException;
+use OCA\Sharing\Manager;
+use OCA\Sharing\Model\ShareAccessContext;
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Input\InputArgument;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Output\OutputInterface;
+
+class Get extends Command {
+	public function __construct(
+		private readonly Manager $manager,
+	) {
+		parent::__construct();
+	}
+
+	protected function configure(): void {
+		$this
+			->setName('share:get')
+			->setDescription('get the data of a share')
+			->addArgument('id', InputArgument::REQUIRED, 'Share ID');
+	}
+
+	public function execute(InputInterface $input, OutputInterface $output): int {
+		$id = (string)$input->getArgument('id');
+
+		try {
+			$share = $this->manager->get(new ShareAccessContext(force: true), $id);
+		} catch (AShareException $aShareException) {
+			$output->writeln($aShareException->getMessage());
+			return 1;
+		}
+
+		$output->writeln(json_encode($share->toArray(), JSON_THROW_ON_ERROR | JSON_PRETTY_PRINT));
+		return 0;
+	}
+}

apps/sharing/lib/Command/Update.php

@@ -0,0 +1,61 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+namespace OCA\Sharing\Command;
+
+use OCA\Sharing\Exception\AShareException;
+use OCA\Sharing\Manager;
+use OCA\Sharing\Model\Share;
+use OCA\Sharing\Model\ShareAccessContext;
+use OCA\Sharing\ResponseDefinitions;
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Input\InputArgument;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Output\OutputInterface;
+
+/**
+ * @psalm-import-type SharingShare from ResponseDefinitions
+ */
+class Update extends Command {
+	public function __construct(
+		private readonly Manager $manager,
+	) {
+		parent::__construct();
+	}
+
+	protected function configure(): void {
+		$this
+			->setName('share:update')
+			->setDescription('update an existing share')
+			->addArgument('data', InputArgument::REQUIRED, 'Share data');
+	}
+
+	public function execute(InputInterface $input, OutputInterface $output): int {
+		/** @var SharingShare $data */
+		$data = json_decode((string)$input->getArgument('data'), true, 512, JSON_THROW_ON_ERROR);
+		$share = Share::fromArray($data);
+
+		try {
+			$this->manager->update(new ShareAccessContext(force: true), $share);
+		} catch (AShareException $aShareException) {
+			$output->writeln($aShareException->getMessage());
+			return 1;
+		}
+
+		try {
+			$share = $this->manager->get(new ShareAccessContext(force: true), $share->id);
+		} catch (AShareException $aShareException) {
+			$output->writeln($aShareException->getMessage());
+			return 1;
+		}
+
+		$output->writeln(json_encode($share->toArray(), JSON_THROW_ON_ERROR | JSON_PRETTY_PRINT));
+		return 0;
+	}
+}

apps/sharing/lib/Controller/ApiV1Controller.php

@@ -0,0 +1,262 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+namespace OCA\Sharing\Controller;
+
+use OCA\Sharing\Exception\ShareConflictException;
+use OCA\Sharing\Exception\ShareInvalidException;
+use OCA\Sharing\Exception\ShareInvalidOperationParameterException;
+use OCA\Sharing\Exception\ShareNotFoundException;
+use OCA\Sharing\Exception\ShareOperationNotAllowedException;
+use OCA\Sharing\Manager;
+use OCA\Sharing\Model\IShareFeatureFilter;
+use OCA\Sharing\Model\IShareRecipientType;
+use OCA\Sharing\Model\IShareSourceType;
+use OCA\Sharing\Model\Share;
+use OCA\Sharing\Model\ShareAccessContext;
+use OCA\Sharing\Model\ShareRecipientSearchResult;
+use OCA\Sharing\ResponseDefinitions;
+use OCP\AppFramework\Http;
+use OCP\AppFramework\Http\Attribute\AnonRateLimit;
+use OCP\AppFramework\Http\Attribute\ApiRoute;
+use OCP\AppFramework\Http\Attribute\NoAdminRequired;
+use OCP\AppFramework\Http\Attribute\PublicPage;
+use OCP\AppFramework\Http\Attribute\UserRateLimit;
+use OCP\AppFramework\Http\DataResponse;
+use OCP\AppFramework\OCSController;
+use OCP\IRequest;
+use OCP\IUserSession;
+
+// TODO: Rate limit recipients during share create and update
+// TODO: Add federation
+
+/**
+ * @psalm-import-type SharingShare from ResponseDefinitions
+ * @psalm-import-type SharingPartialShare from ResponseDefinitions
+ * @psalm-import-type SharingFeature from ResponseDefinitions
+ * @psalm-import-type SharingRecipientSearchResult from ResponseDefinitions
+ */
+class ApiV1Controller extends OCSController {
+	public function __construct(
+		string $appName,
+		IRequest $request,
+		private readonly IUserSession $userSession,
+		private readonly Manager $manager,
+	) {
+		parent::__construct($appName, $request);
+	}
+
+	/**
+	 * Searches for recipients
+	 *
+	 * @param ?class-string<IShareRecipientType> $recipientType Type of the recipients
+	 * @param non-empty-string $query The query to search for
+	 * @param int<1, 100> $limit The maximum number of participants
+	 * @param non-negative-int $offset The offset of the participants
+	 * @return DataResponse<Http::STATUS_OK, list<SharingRecipientSearchResult>, array{}>|DataResponse<Http::STATUS_BAD_REQUEST, string, array{}>
+	 *
+	 * 200: Recipients returned
+	 * 400: Bad recipient search parameters
+	 */
+	#[UserRateLimit(limit: 1, period: 1)]
+	#[NoAdminRequired]
+	#[ApiRoute(verb: 'GET', url: '/api/v1/recipients')]
+	public function searchRecipients(?string $recipientType, string $query, int $limit = 10, int $offset = 0): DataResponse {
+		/** @psalm-suppress TypeDoesNotContainType */
+		if ($query === '') {
+			throw new ShareInvalidOperationParameterException('The query is empty.');
+		}
+
+		/** @psalm-suppress DocblockTypeContradiction */
+		if ($limit < 1) {
+			throw new ShareInvalidOperationParameterException('The limit is too low.');
+		}
+
+		/** @psalm-suppress DocblockTypeContradiction */
+		if ($limit > 100) {
+			throw new ShareInvalidOperationParameterException('The limit is too high.');
+		}
+
+		/** @psalm-suppress DocblockTypeContradiction */
+		if ($offset < 0) {
+			throw new ShareInvalidOperationParameterException('The offset is too low.');
+		}
+
+		try {
+			$recipientSearchResults = $this->manager->searchRecipients($recipientType, $query, $limit, $offset);
+		} catch (ShareInvalidOperationParameterException $shareInvalidOperationParameterException) {
+			return new DataResponse($shareInvalidOperationParameterException->getMessage(), Http::STATUS_BAD_REQUEST);
+		}
+
+		return new DataResponse(array_map(static fn (ShareRecipientSearchResult $result): array => $result->toArray(), $recipientSearchResults));
+	}
+
+	/**
+	 * Creates a new share
+	 *
+	 * @param SharingPartialShare $data The new share data
+	 * @return DataResponse<Http::STATUS_CREATED, SharingShare, array{}>|DataResponse<Http::STATUS_BAD_REQUEST|Http::STATUS_UNAUTHORIZED|Http::STATUS_FORBIDDEN, string, array{}>
+	 *
+	 * 201: Share created successfully
+	 * 400: Invalid share data
+	 * 403: Creating the share is not allowed
+	 */
+	#[UserRateLimit(limit: 1, period: 5)]
+	#[NoAdminRequired]
+	#[ApiRoute(verb: 'POST', url: '/api/v1/share')]
+	public function createShare(array $data): DataResponse {
+		$user = $this->userSession->getUser();
+		if ($user === null) {
+			return new DataResponse('Not logged in', Http::STATUS_UNAUTHORIZED);
+		}
+
+		$share = Share::fromArray($this->manager->completePartialShareData($data));
+
+		try {
+			$this->manager->insert($share);
+		} catch (ShareInvalidException $e) {
+			return new DataResponse($e->getMessage(), Http::STATUS_BAD_REQUEST);
+		} catch (ShareOperationNotAllowedException $e) {
+			return new DataResponse($e->getMessage(), Http::STATUS_FORBIDDEN);
+		}
+
+		return new DataResponse($this->manager->get(new ShareAccessContext(force: true), $share->id)->toArray(), Http::STATUS_CREATED);
+	}
+
+
+	/**
+	 * Gets a share
+	 *
+	 * @param string $id ID of the share
+	 * @param array<class-string<IShareRecipientType|IShareFeatureFilter>, mixed> $arguments Arguments for accessing the share
+	 * @return DataResponse<Http::STATUS_OK, SharingShare, array{}>|DataResponse<Http::STATUS_NOT_FOUND, string, array{}>
+	 *
+	 * 200: Share returned
+	 * 404: Share not found
+	 */
+	#[UserRateLimit(limit: 1, period: 1)]
+	#[AnonRateLimit(limit: 1, period: 5)]
+	#[PublicPage]
+	// This should be a GET, but GET doesn't allow a request body which is required for the $arguments.
+	#[ApiRoute(verb: 'POST', url: '/api/v1/share/{id}')]
+	public function getShare(string $id, array $arguments = []): DataResponse {
+		$user = $this->userSession->getUser();
+
+		try {
+			$share = $this->manager->get(new ShareAccessContext($user, $arguments), $id);
+		} catch (ShareNotFoundException $shareNotFoundException) {
+			return new DataResponse($shareNotFoundException->getMessage(), Http::STATUS_NOT_FOUND);
+		}
+
+		return new DataResponse($share->toArray());
+	}
+
+	/**
+	 * Gets all shares
+	 *
+	 * @param ?class-string<IShareSourceType> $sourceType Filter by source type.
+	 * @param ?string $lastShareId The ID of the previous share. This is used as an offset and only shares with higher IDs are returned.
+	 * @param int<1, 100> $limit The number of shares to return.
+	 * @return DataResponse<Http::STATUS_OK, list<SharingShare>, array{}>|DataResponse<Http::STATUS_UNAUTHORIZED, string, array{}>
+	 *
+	 * 200: Shares returned
+	 */
+	#[UserRateLimit(limit: 1, period: 5)]
+	#[NoAdminRequired]
+	#[ApiRoute(verb: 'GET', url: '/api/v1/shares')]
+	public function getShares(?string $sourceType = null, ?string $lastShareId = null, int $limit = 100) {
+		$user = $this->userSession->getUser();
+		if ($user === null) {
+			return new DataResponse('Not logged in', Http::STATUS_UNAUTHORIZED);
+		}
+
+		/** @psalm-suppress DocblockTypeContradiction */
+		if ($limit < 1) {
+			throw new ShareInvalidOperationParameterException('The limit is too low.');
+		}
+
+		/** @psalm-suppress DocblockTypeContradiction */
+		if ($limit > 100) {
+			throw new ShareInvalidOperationParameterException('The limit is too high.');
+		}
+
+		$shares = $this->manager->list(new ShareAccessContext($user), $sourceType, $lastShareId, $limit);
+
+		return new DataResponse(array_map(static fn (Share $share): array => $share->toArray(), $shares));
+	}
+
+	/**
+	 * Updates a share
+	 *
+	 * @param non-empty-string $id ID of the share
+	 * @param SharingShare $data The updated share data
+	 * @return DataResponse<Http::STATUS_OK, SharingShare, array{}>|DataResponse<Http::STATUS_BAD_REQUEST|Http::STATUS_UNAUTHORIZED|Http::STATUS_NOT_FOUND|Http::STATUS_CONFLICT, string, array{}>
+	 *
+	 * 200: Share updated
+	 * 400: Invalid share data
+	 * 404: Share not found
+	 * 409: The share has been updated in the meantime, so you cannot update it.
+	 */
+	#[UserRateLimit(limit: 1, period: 1)]
+	#[NoAdminRequired]
+	#[ApiRoute(verb: 'PUT', url: '/api/v1/share/{id}')]
+	public function updateShare(string $id, array $data): DataResponse {
+		$user = $this->userSession->getUser();
+		if ($user === null) {
+			return new DataResponse('Not logged in', Http::STATUS_UNAUTHORIZED);
+		}
+
+		if ($data['id'] !== $id) {
+			return new DataResponse('Share IDs do not match', Http::STATUS_BAD_REQUEST);
+		}
+
+		$share = Share::fromArray($data);
+
+		try {
+			$this->manager->update(new ShareAccessContext($user), $share);
+		} catch (ShareInvalidException $e) {
+			return new DataResponse($e->getMessage(), Http::STATUS_BAD_REQUEST);
+		} catch (ShareNotFoundException $e) {
+			return new DataResponse($e->getMessage(), Http::STATUS_NOT_FOUND);
+		} catch (ShareConflictException $e) {
+			return new DataResponse($e->getMessage(), Http::STATUS_CONFLICT);
+		}
+
+		$share = $this->manager->get(new ShareAccessContext($user), $share->id);
+
+		return new DataResponse($share->toArray());
+	}
+
+	/**
+	 * Deletes a share
+	 *
+	 * @param string $id ID of the share
+	 * @return DataResponse<Http::STATUS_NO_CONTENT, list<empty>, array{}>|DataResponse<Http::STATUS_UNAUTHORIZED|Http::STATUS_NOT_FOUND, string, array{}>
+	 *
+	 * 204: Share deleted
+	 * 404: Share not found
+	 */
+	#[UserRateLimit(limit: 1, period: 1)]
+	#[NoAdminRequired]
+	#[ApiRoute(verb: 'DELETE', url: '/api/v1/share/{id}')]
+	public function deleteShare(string $id): DataResponse {
+		$user = $this->userSession->getUser();
+		if ($user === null) {
+			return new DataResponse('Not logged in', Http::STATUS_UNAUTHORIZED);
+		}
+
+		try {
+			$this->manager->delete(new ShareAccessContext($user), $id);
+		} catch (ShareNotFoundException $shareNotFoundException) {
+			return new DataResponse($shareNotFoundException->getMessage(), Http::STATUS_NOT_FOUND);
+		}
+
+		return new DataResponse([], Http::STATUS_NO_CONTENT);
+	}
+}

apps/sharing/lib/Exception/AShareException.php

@@ -0,0 +1,15 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+namespace OCA\Sharing\Exception;
+
+use Exception;
+
+abstract class AShareException extends Exception {
+}

apps/sharing/lib/Exception/ShareConflictException.php

@@ -0,0 +1,16 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+namespace OCA\Sharing\Exception;
+
+class ShareConflictException extends AShareException {
+	public function __construct() {
+		parent::__construct('The share has been updated in the meantime, so you cannot update it.');
+	}
+}

apps/sharing/lib/Exception/ShareInvalidException.php

@@ -0,0 +1,16 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+namespace OCA\Sharing\Exception;
+
+class ShareInvalidException extends AShareException {
+	public function __construct(string $message) {
+		parent::__construct('Invalid share: ' . $message);
+	}
+}

apps/sharing/lib/Exception/ShareInvalidOperationParameterException.php

@@ -0,0 +1,16 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+namespace OCA\Sharing\Exception;
+
+class ShareInvalidOperationParameterException extends AShareException {
+	public function __construct(string $parameter) {
+		parent::__construct('Invalid operation parameter: ' . $parameter);
+	}
+}

apps/sharing/lib/Exception/ShareInvalidPropertiesException.php

@@ -0,0 +1,21 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+namespace OCA\Sharing\Exception;
+
+use OCA\Sharing\Model\IShareFeature;
+
+class ShareInvalidPropertiesException extends ShareInvalidException {
+	/**
+	 * @param class-string<IShareFeature> $feature
+	 */
+	public function __construct(string $feature) {
+		parent::__construct('The properties for feature ' . $feature . ' are not valid.');
+	}
+}

apps/sharing/lib/Exception/ShareNotFoundException.php

@@ -0,0 +1,16 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+namespace OCA\Sharing\Exception;
+
+class ShareNotFoundException extends AShareException {
+	public function __construct(string $shareID) {
+		parent::__construct('Share ' . $shareID . ' not found.');
+	}
+}

apps/sharing/lib/Exception/ShareOperationNotAllowedException.php

@@ -0,0 +1,16 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+namespace OCA\Sharing\Exception;
+
+class ShareOperationNotAllowedException extends AShareException {
+	public function __construct() {
+		parent::__construct('Share operation not allowed.');
+	}
+}

apps/sharing/lib/Manager.php

@@ -0,0 +1,585 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+namespace OCA\Sharing;
+
+use OCA\Sharing\Exception\ShareConflictException;
+use OCA\Sharing\Exception\ShareInvalidException;
+use OCA\Sharing\Exception\ShareInvalidOperationParameterException;
+use OCA\Sharing\Exception\ShareInvalidPropertiesException;
+use OCA\Sharing\Exception\ShareNotFoundException;
+use OCA\Sharing\Exception\ShareOperationNotAllowedException;
+use OCA\Sharing\Model\IShareFeature;
+use OCA\Sharing\Model\IShareFeatureFilter;
+use OCA\Sharing\Model\IShareFeatureModifyProperties;
+use OCA\Sharing\Model\IShareRecipientType;
+use OCA\Sharing\Model\IShareRecipientTypeSearch;
+use OCA\Sharing\Model\IShareSourceType;
+use OCA\Sharing\Model\Share;
+use OCA\Sharing\Model\ShareAccessContext;
+use OCA\Sharing\Model\ShareRecipientSearchResult;
+use OCP\DB\Exception;
+use OCP\DB\QueryBuilder\IQueryBuilder;
+use OCP\IDBConnection;
+use OCP\IUser;
+use OCP\IUserManager;
+use OCP\Server;
+use OCP\Snowflake\ISnowflakeGenerator;
+use RuntimeException;
+
+// TODO: Add permission model
+// TODO: Add reshares
+// TODO: Add listeners to remove recipients and sources when they are deleted
+// TODO: Update throws annotations and catch them in the controller
+
+/**
+ * @psalm-import-type SharingShare from ResponseDefinitions
+ * @psalm-import-type SharingPartialShare from ResponseDefinitions
+ */
+class Manager {
+	public function __construct(
+		private readonly IDBConnection $connection,
+		private readonly Registry $registry,
+		private readonly IUserManager $userManager,
+	) {
+	}
+
+	/**
+	 * @param SharingPartialShare $share
+	 * @return SharingShare
+	 */
+	public function completePartialShareData(array $share): array {
+		$share['id'] = Server::get(ISnowflakeGenerator::class)->nextId();
+		$share['last_updated'] = $this->generateLastUpdated();
+		return $share;
+	}
+
+	/**
+	 * @return non-negative-int
+	 */
+	private function generateLastUpdated(): int {
+		$time = (int)(microtime(true) * 1000);
+		if ($time < 0) {
+			throw new RuntimeException('Have you invented time travel?');
+		}
+
+		return $time;
+	}
+
+	/**
+	 * @param ?class-string<IShareRecipientType> $recipientTypeClass
+	 * @param non-empty-string $query
+	 * @param positive-int $limit
+	 * @param non-negative-int $offset
+	 * @return list<ShareRecipientSearchResult>
+	 * @throws ShareInvalidOperationParameterException
+	 */
+	public function searchRecipients(?string $recipientTypeClass, string $query, int $limit, int $offset): array {
+		$recipientTypes = $this->registry->getRecipientTypes();
+
+		if ($recipientTypeClass !== null) {
+			if (!isset($recipientTypes[$recipientTypeClass])) {
+				throw new ShareInvalidOperationParameterException('The recipient type is not registered.');
+			}
+
+			$recipientTypes = [($recipientTypes[$recipientTypeClass])];
+		}
+
+		$searchableRecipientTypes = array_values(array_filter(
+			$recipientTypes,
+			static fn (IShareRecipientType $recipientType): bool => $recipientType instanceof IShareRecipientTypeSearch,
+		));
+
+		return array_merge(...array_map(
+			static fn (IShareRecipientTypeSearch $recipientType): array => array_map(
+				static fn (ShareRecipientSearchResult $result): ShareRecipientSearchResult => $result->setType($recipientType::class),
+				$recipientType->searchRecipients($query, $limit, $offset),
+			),
+			$searchableRecipientTypes,
+		));
+	}
+
+	/**
+	 * @throws ShareOperationNotAllowedException
+	 */
+	private function validateShareOwnerOperation(ShareAccessContext $accessContext, Share $share): void {
+		if ($accessContext->force) {
+			return;
+		}
+
+		if (!$accessContext->currentUser instanceof IUser) {
+			throw new ShareOperationNotAllowedException();
+		}
+
+		if ($share->owner->userId !== $accessContext->currentUser->getUID()) {
+			throw new ShareOperationNotAllowedException();
+		}
+	}
+
+	/**
+	 * The share might be updated during insertion (e.g. display name changes),
+	 * so if you use the share afterwards get it from the manager again.
+	 *
+	 * @throws ShareOperationNotAllowedException
+	 * @throws ShareInvalidException
+	 */
+	public function insert(Share $share): void {
+		/** @psalm-suppress PossiblyNullReference Can't happen since share is valid */
+		$ownerDisplayName = $this->userManager->get($share->owner->userId)->getDisplayName();
+
+		$this->connection->beginTransaction();
+
+		$qb = $this->connection->getQueryBuilder();
+		$qb
+			->insert('sharing_share')
+			->values([
+				'id' => $qb->createNamedParameter((int)$share->id, IQueryBuilder::PARAM_INT),
+				'owner' => $qb->createNamedParameter($share->owner->userId),
+				'owner_display_name' => $qb->createNamedParameter($ownerDisplayName),
+				'last_updated' => $qb->createNamedParameter($share->lastUpdated),
+			])
+			->executeStatement();
+
+		$this->insertSources($share);
+		$this->insertRecipients($share);
+		$this->insertProperties($share);
+
+		try {
+			$this->connection->commit();
+		} catch (Exception $exception) {
+			$this->connection->rollBack();
+			throw $exception;
+		}
+	}
+
+	private function insertSources(Share $share): void {
+		$qb = $this->connection->getQueryBuilder()
+			->insert('sharing_share_sources');
+		foreach ($share->sources as $source) {
+			/** @psalm-suppress PossiblyNullReference Can't happen since share is valid */
+			$sourceDisplayName = $this->registry->getSourceTypes()[$source->type]->getSourceDisplayName($source->value) ?? $source->value;
+
+			$qb
+				->values([
+					'id' => $qb->createNamedParameter((int)$share->id, IQueryBuilder::PARAM_INT),
+					'source_type' => $qb->createNamedParameter($source->type),
+					'source_value' => $qb->createNamedParameter($source->value),
+					'source_display_name' => $qb->createNamedParameter($sourceDisplayName),
+				])
+				->executeStatement();
+		}
+	}
+
+	private function insertRecipients(Share $share): void {
+		$qb = $this->connection->getQueryBuilder()
+			->insert('sharing_share_recipients');
+		foreach ($share->recipients as $recipient) {
+			/** @psalm-suppress PossiblyNullReference Can't happen since share is valid */
+			$recipientDisplayName = $this->registry->getRecipientTypes()[$recipient->type]->getRecipientDisplayName($recipient->value) ?? $recipient->value;
+
+			$qb
+				->values([
+					'id' => $qb->createNamedParameter((int)$share->id, IQueryBuilder::PARAM_INT),
+					'recipient_type' => $qb->createNamedParameter($recipient->type),
+					'recipient_value' => $qb->createNamedParameter($recipient->value),
+					'recipient_display_name' => $qb->createNamedParameter($recipientDisplayName),
+				])
+				->executeStatement();
+		}
+	}
+
+	private function insertProperties(Share $share): void {
+		$features = $this->registry->getFeatures();
+
+		$qb = $this->connection->getQueryBuilder()
+			->insert('sharing_share_properties');
+		foreach ($share->properties as $featureClass => $properties) {
+			if ($features[$featureClass] instanceof IShareFeatureModifyProperties) {
+				// Properties are already validated when the Share object is created.
+				$properties = $features[$featureClass]->modifyProperties($properties);
+				if (!$features[$featureClass]->validateProperties($properties)) {
+					throw new ShareInvalidPropertiesException($featureClass);
+				}
+			}
+
+			foreach ($properties as $key => $values) {
+				foreach ($values as $value) {
+					$qb
+						->values([
+							'id' => $qb->createNamedParameter((int)$share->id, IQueryBuilder::PARAM_INT),
+							'feature' => $qb->createNamedParameter($featureClass),
+							'feature_key' => $qb->createNamedParameter($key),
+							'feature_value' => $qb->createNamedParameter($value),
+						])
+						->executeStatement();
+				}
+			}
+		}
+	}
+
+	/**
+	 *  The share might be updated during insertion (e.g. display name updates),
+	 *  so if you use the share afterwards get it from the manager again.
+	 *
+	 * @throws ShareConflictException
+	 * @throws ShareInvalidException
+	 * @throws ShareInvalidPropertiesException
+	 * @throws ShareNotFoundException
+	 * @throws ShareOperationNotAllowedException
+	 */
+	public function update(ShareAccessContext $accessContext, Share $share): void {
+		$originalShare = $this->get($accessContext, $share->id);
+		$this->validateShareOwnerOperation($accessContext, $originalShare);
+
+		if ($share->id !== $originalShare->id) {
+			throw new ShareInvalidException('The id cannot be updated.');
+		}
+
+		if ($share->lastUpdated !== $originalShare->lastUpdated) {
+			// TODO: Add test
+			throw new ShareConflictException();
+		}
+
+		/** @psalm-suppress PossiblyNullReference Can't happen since share is valid */
+		$ownerDisplayName = $this->userManager->get($share->owner->userId)->getDisplayName();
+
+		$this->connection->beginTransaction();
+
+		$qb = $this->connection->getQueryBuilder();
+		$qb
+			->update('sharing_share')
+			->set('owner', $qb->createNamedParameter($share->owner->userId))
+			->set('owner_display_name', $qb->createNamedParameter($ownerDisplayName))
+			->set('last_updated', $qb->createNamedParameter($this->generateLastUpdated()))
+			->where($qb->expr()->eq('id', $qb->createNamedParameter($share->id)))
+			->executeStatement();
+
+		$this->deleteSources($share->id);
+		$this->insertSources($share);
+
+		$this->deleteRecipients($share->id);
+		$this->insertRecipients($share);
+
+		$this->deleteProperties($share->id);
+		$this->insertProperties($share);
+
+		try {
+			$this->connection->commit();
+		} catch (Exception $exception) {
+			$this->connection->rollBack();
+			throw $exception;
+		}
+	}
+
+	/**
+	 * @throws ShareNotFoundException
+	 * @throws ShareOperationNotAllowedException
+	 */
+	public function delete(ShareAccessContext $accessContext, string $shareID): void {
+		$originalShare = $this->get($accessContext, $shareID);
+		$this->validateShareOwnerOperation($accessContext, $originalShare);
+
+		$this->connection->beginTransaction();
+
+		$qb = $this->connection->getQueryBuilder();
+		$qb
+			->delete('sharing_share')
+			->where($qb->expr()->eq('id', $qb->createNamedParameter((int)$shareID, IQueryBuilder::PARAM_INT)))
+			->executeStatement();
+
+		$this->deleteSources($shareID);
+		$this->deleteRecipients($shareID);
+		$this->deleteProperties($shareID);
+
+		try {
+			$this->connection->commit();
+		} catch (Exception $exception) {
+			$this->connection->rollBack();
+			throw $exception;
+		}
+	}
+
+	private function deleteSources(string $shareID): void {
+		$qb = $this->connection->getQueryBuilder();
+		$qb
+			->delete('sharing_share_sources')
+			->where($qb->expr()->eq('id', $qb->createNamedParameter((int)$shareID, IQueryBuilder::PARAM_INT)))
+			->executeStatement();
+	}
+
+	private function deleteRecipients(string $shareID): void {
+		$qb = $this->connection->getQueryBuilder();
+		$qb
+			->delete('sharing_share_recipients')
+			->where($qb->expr()->eq('id', $qb->createNamedParameter((int)$shareID, IQueryBuilder::PARAM_INT)))
+			->executeStatement();
+	}
+
+	private function deleteProperties(string $shareID): void {
+		$qb = $this->connection->getQueryBuilder();
+		$qb
+			->delete('sharing_share_properties')
+			->where($qb->expr()->eq('id', $qb->createNamedParameter((int)$shareID, IQueryBuilder::PARAM_INT)))
+			->executeStatement();
+	}
+
+	/**
+	 * @throws ShareNotFoundException
+	 */
+	public function get(ShareAccessContext $accessContext, string $shareID): Share {
+		$shares = $this->internalList($accessContext, $shareID, null, null, null);
+		if (count($shares) !== 1) {
+			throw new ShareNotFoundException($shareID);
+		}
+
+		return $shares[0];
+	}
+
+	/**
+	 * @param ?class-string<IShareSourceType> $sourceType
+	 * @return list<Share>
+	 */
+	public function list(ShareAccessContext $accessContext, ?string $sourceType, ?string $lastShareId, ?int $limit): array {
+		return $this->internalList($accessContext, null, $sourceType, $lastShareId, $limit);
+	}
+
+	/**
+	 * @param ?class-string<IShareSourceType> $sourceType
+	 * @return list<Share>
+	 */
+	private function internalList(ShareAccessContext $accessContext, ?string $shareID, ?string $sourceType, ?string $lastShareId, ?int $limit): array {
+		// LEFT JOINing all tables works, but causes a lot of rows to be selected and would require deduplication.
+
+		/** @var list<IQueryBuilder> $queries */
+		$queries = [];
+		if ($accessContext->force) {
+			$queries[] = $this->connection->getQueryBuilder();
+		} else {
+			// Because doctrine has no UNION support, individual queries have to be used
+
+			if ($accessContext->currentUser instanceof IUser) {
+				$qb = $this->connection->getQueryBuilder();
+				$qb->where($qb->expr()->eq('s.owner', $qb->createNamedParameter($accessContext->currentUser->getUID())));
+				$queries[] = $qb;
+			}
+
+			/** @var array<class-string<IShareRecipientType>, list<string>> $recipients */
+			$recipients = [];
+			foreach ($this->registry->getRecipientTypes() as $recipientType) {
+				$recipientValues = $recipientType->getRecipientValues($accessContext->currentUser, $accessContext->arguments[$recipientType::class] ?? null);
+				if ($recipientValues !== []) {
+					$recipients[$recipientType::class] = $recipientValues;
+				}
+			}
+
+			// Do not add a query if no recipients matched, otherwise all shares will be returned.
+			if ($recipients !== []) {
+				$qb = $this->connection->getQueryBuilder();
+				$qb->innerJoin('s', 'sharing_share_recipients', 'sr', $qb->expr()->eq('sr.id', 's.id'));
+
+				foreach ($recipients as $recipientTypeClass => $recipientValues) {
+					$qb->orWhere($qb->expr()->andX(
+						$qb->expr()->eq('recipient_type', $qb->createNamedParameter($recipientTypeClass)),
+						// TODO: Add chunking
+						$qb->expr()->in('recipient_value', $qb->createNamedParameter($recipientValues, IQueryBuilder::PARAM_STR_ARRAY)),
+					));
+				}
+
+				$queries[] = $qb;
+			}
+		}
+
+		/** @var array<string, SharingShare> $shares */
+		$shares = [];
+		foreach ($queries as $qb) {
+			$qb
+				->select(
+					's.id',
+					's.owner',
+					's.owner_display_name',
+					's.last_updated',
+				)
+				->from('sharing_share', 's')
+				->orderBy('s.id', 'ASC');
+
+			if ($shareID !== null) {
+				$qb->andWhere($qb->expr()->eq('s.id', $qb->createNamedParameter((int)$shareID, IQueryBuilder::PARAM_INT)));
+			}
+
+			if ($sourceType !== null) {
+				$qb->innerJoin('s', 'sharing_share_sources', 'ss', $qb->expr()->andX(
+					$qb->expr()->eq('s.id', 'ss.id'),
+					$qb->expr()->eq('ss.source_type', $qb->createNamedParameter($sourceType)),
+				));
+			}
+
+			if ($lastShareId !== null) {
+				if (!ctype_digit($lastShareId)) {
+					throw new ShareInvalidOperationParameterException('The lastShareId is invalid.');
+				}
+
+				$qb->andWhere($qb->expr()->gt('s.id', $qb->createNamedParameter((int)$lastShareId, IQueryBuilder::PARAM_INT)));
+			}
+
+			if ($limit !== null) {
+				$qb->setMaxResults($limit);
+			}
+
+			$result = $qb->executeQuery();
+			$rows = $result->fetchAll();
+			foreach ($rows as $row) {
+				$id = (string)$row['id'];
+				$shares[$id] ??= [
+					'id' => $id,
+					'owner' => [
+						'user_id' => (string)$row['owner'],
+						'display_name' => (string)$row['owner_display_name'],
+					],
+					'last_updated' => (int)$row['last_updated'],
+					'sources' => [],
+					'recipients' => [],
+					'properties' => [],
+				];
+			}
+		}
+
+		// If multiple queries are used the shares are not automatically sorted already.
+		if (count($queries) > 1) {
+			ksort($shares);
+		}
+
+		// The queries are limited already, but could return more results in total, so discard them here.
+		if ($limit !== null) {
+			$shares = array_slice($shares, 0, $limit, true);
+		}
+
+		$chunks = array_chunk(array_keys($shares), 1000);
+
+		foreach ($chunks as $chunk) {
+			$qb = $this->connection->getQueryBuilder();
+			$qb
+				->select(
+					'id',
+					'recipient_type',
+					'recipient_value',
+					'recipient_display_name',
+				)
+				->from('sharing_share_recipients')
+				->where($qb->expr()->in('id', $qb->createNamedParameter($chunk, IQueryBuilder::PARAM_INT_ARRAY)));
+
+			$result = $qb->executeQuery();
+			foreach ($result->fetchAll() as $row) {
+				$id = (string)$row['id'];
+				$shares[$id]['recipients'][] = [
+					'type' => (string)$row['recipient_type'],
+					'value' => (string)$row['recipient_value'],
+					'display_name' => (string)$row['recipient_display_name'],
+				];
+			}
+		}
+
+		foreach ($chunks as $chunk) {
+			$qb = $this->connection->getQueryBuilder();
+			$qb
+				->select(
+					'id',
+					'feature',
+					'feature_key',
+					'feature_value',
+				)
+				->from('sharing_share_properties')
+				->where($qb->expr()->in('id', $qb->createNamedParameter($chunk, IQueryBuilder::PARAM_INT_ARRAY)));
+
+			$result = $qb->executeQuery();
+			foreach ($result->fetchAll() as $row) {
+				$id = (string)$row['id'];
+
+				$shares[$id]['properties'][(string)$row['feature']] ??= [];
+				$shares[$id]['properties'][(string)$row['feature']][(string)$row['feature_key']] ??= [];
+				$shares[$id]['properties'][(string)$row['feature']][(string)$row['feature_key']][] = (string)$row['feature_value'];
+			}
+		}
+
+		foreach ($chunks as $chunk) {
+			$qb = $this->connection->getQueryBuilder();
+			$qb
+				->select(
+					'id',
+					'source_type',
+					'source_value',
+					'source_display_name',
+				)
+				->from('sharing_share_sources')
+				->where($qb->expr()->in('id', $qb->createNamedParameter($chunk, IQueryBuilder::PARAM_INT_ARRAY)));
+
+			$result = $qb->executeQuery();
+			foreach ($result->fetchAll() as $row) {
+				$id = (string)$row['id'];
+
+				$shares[$id]['sources'][] = [
+					'type' => (string)$row['source_type'],
+					'value' => (string)$row['source_value'],
+					'display_name' => (string)$row['source_display_name'],
+				];
+			}
+		}
+
+		if (!$accessContext->force) {
+			$filterFeatures = array_filter($this->registry->getFeatures(), static fn (IShareFeature $feature): bool => $feature instanceof IShareFeatureFilter);
+			if ($filterFeatures !== []) {
+				// Some filtering needs more logic than the database is able to provide, so it is done in the backend.
+				// TODO: This can still be quite expensive for many shares, so caching the filter results might be sensible at some point.
+				$shares = array_filter($shares, function (array $share) use ($filterFeatures, $accessContext): bool {
+					if ($accessContext->currentUser?->getUID() === $share['owner']['user_id']) {
+						return true;
+					}
+
+					/** @var array<class-string<IShareSourceType>, bool> $shareSourceTypes */
+					$shareSourceTypes = [];
+					foreach ($share['sources'] as $source) {
+						$shareSourceTypes[$source['type']] = true;
+					}
+
+					/** @var array<class-string<IShareRecipientType>, bool> $shareRecipientTypes */
+					$shareRecipientTypes = [];
+					foreach ($share['recipients'] as $recipient) {
+						$shareRecipientTypes[$recipient['type']] = true;
+					}
+
+					foreach ($filterFeatures as $feature) {
+						$isCompatible = false;
+						foreach ($feature->getCompatibles() as $compatible) {
+							if (isset($shareSourceTypes[$compatible['source_type']], $shareRecipientTypes[$compatible['recipient_type']])) {
+								$isCompatible = true;
+								break;
+							}
+						}
+
+						if (!$isCompatible) {
+							continue;
+						}
+
+						if ($feature->isFiltered(
+							$accessContext->currentUser,
+							$accessContext->arguments[$feature::class] ?? null,
+							$share['properties'][$feature::class] ?? [],
+						)) {
+							return false;
+						}
+					}
+
+					return true;
+				});
+			}
+		}
+
+		/** @psalm-suppress ArgumentTypeCoercion */
+		return array_map(Share::fromArray(...), array_values($shares));
+	}
+}

apps/sharing/lib/Migration/Version1000Date20250929161325.php

@@ -0,0 +1,59 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+
+namespace OCA\Sharing\Migration;
+
+use Closure;
+use Doctrine\DBAL\Schema\SchemaException;
+use OCP\DB\ISchemaWrapper;
+use OCP\DB\Types;
+use OCP\Migration\IOutput;
+use OCP\Migration\SimpleMigrationStep;
+use Override;
+
+class Version1000Date20250929161325 extends SimpleMigrationStep {
+	/**
+	 * @param Closure():ISchemaWrapper $schemaClosure
+	 * @throws SchemaException
+	 */
+	#[Override]
+	public function changeSchema(IOutput $output, Closure $schemaClosure, array $options): ?ISchemaWrapper {
+		$schema = $schemaClosure();
+
+		$shareTable = $schema->createTable('sharing_share');
+		$shareTable->addColumn('id', Types::BIGINT);
+		$shareTable->addColumn('owner', Types::TEXT);
+		$shareTable->addColumn('owner_display_name', Types::TEXT, ['notnull' => false]);
+		$shareTable->addColumn('last_updated', Types::BIGINT);
+
+		$sourcesTable = $schema->createTable('sharing_share_sources');
+		$sourcesTable->addColumn('id', Types::BIGINT);
+		$sourcesTable->addColumn('source_type', Types::TEXT);
+		$sourcesTable->addColumn('source_value', Types::TEXT);
+		$sourcesTable->addColumn('source_display_name', Types::TEXT, ['notnull' => false]);
+
+		$recipientsTable = $schema->createTable('sharing_share_recipients');
+		$recipientsTable->addColumn('id', Types::BIGINT);
+		$recipientsTable->addColumn('recipient_type', Types::TEXT);
+		$recipientsTable->addColumn('recipient_value', Types::TEXT);
+		$recipientsTable->addColumn('recipient_display_name', Types::TEXT, ['notnull' => false]);
+
+		$propertiesTable = $schema->createTable('sharing_share_properties');
+		$propertiesTable->addColumn('id', Types::BIGINT);
+		$propertiesTable->addColumn('feature', Types::TEXT);
+		$propertiesTable->addColumn('feature_key', Types::TEXT);
+		$propertiesTable->addColumn('feature_value', Types::TEXT);
+
+		// TODO: Add primary keys, unique constraints and indices
+		// TODO: Handle unique constraint exceptions
+
+		return $schema;
+	}
+}

apps/sharing/lib/Model/IShareFeature.php

@@ -0,0 +1,33 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+namespace OCA\Sharing\Model;
+
+use OCA\Sharing\ResponseDefinitions;
+
+/**
+ * @psalm-import-type SharingCompatible from ResponseDefinitions
+ * @psalm-import-type SharingFeature from ResponseDefinitions
+ */
+interface IShareFeature {
+	/**
+	 * Get compatible source type and recipient type combinations.
+	 *
+	 * @return non-empty-list<SharingCompatible>
+	 */
+	public function getCompatibles(): array;
+
+	/**
+	 * Validate properties of new shares.
+	 *
+	 * TODO: Maybe tighten to non-empty-list
+	 * @param array<string, list<string>> $properties
+	 */
+	public function validateProperties(array $properties): bool;
+}

apps/sharing/lib/Model/IShareFeatureFilter.php

@@ -0,0 +1,25 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+namespace OCA\Sharing\Model;
+
+use OCP\IUser;
+
+interface IShareFeatureFilter extends IShareFeature {
+	/**
+	 * Evaluates if a share should be filtered out.
+	 *
+	 * Only validated properties will be passed, so validating them again is not necessary.
+	 *
+	 * @param mixed $arguments Defaults to null if no arguments were passed to the Manager
+	 *
+	 * @param array<string, list<string>> $properties
+	 */
+	public function isFiltered(?IUser $currentUser, mixed $arguments, array $properties): bool;
+}

apps/sharing/lib/Model/IShareFeatureModifyProperties.php

@@ -0,0 +1,24 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+namespace OCA\Sharing\Model;
+
+interface IShareFeatureModifyProperties extends IShareFeature {
+	/**
+	 * Modify the properties whenever a share is created or updated.
+	 *
+	 * The properties will be passed to {@see IShareFeature::validateProperties()} before and after the invocation of this method.
+	 * This means you don't need to validate the properties again in the implementation of this method.
+	 *
+	 * TODO: Maybe tighten to non-empty-list
+	 * @param array<string, list<string>> $properties
+	 * @return array<string, list<string>>
+	 */
+	public function modifyProperties(array $properties): array;
+}

apps/sharing/lib/Model/IShareRecipientType.php

@@ -0,0 +1,42 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+namespace OCA\Sharing\Model;
+
+use OCP\IUser;
+
+interface IShareRecipientType {
+	/**
+	 * Returns a user friendly display name for this recipient type.
+	 *
+	 * @return non-empty-string
+	 */
+	public function getDisplayName(): string;
+
+	/**
+	 * Validate that a recipient exists.
+	 *
+	 * @param non-empty-string $recipient
+	 */
+	public function validateRecipient(string $recipient): bool;
+
+	/**
+	 * Get possible recipient values for the current user.
+	 *
+	 * @return list<string>
+	 */
+	// TODO: Add inverse of this method to get users for a recipient
+	public function getRecipientValues(?IUser $currentUser, mixed $arguments): array;
+
+	/**
+	 * @param non-empty-string $recipient
+	 * @return ?non-empty-string
+	 */
+	public function getRecipientDisplayName(string $recipient): ?string;
+}

apps/sharing/lib/Model/IShareRecipientTypeSearch.php

@@ -0,0 +1,22 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+namespace OCA\Sharing\Model;
+
+interface IShareRecipientTypeSearch extends IShareRecipientType {
+	/**
+	 * Search for recipients.
+	 *
+	 * @param non-empty-string $query
+	 * @param positive-int $limit
+	 * @param non-negative-int $offset
+	 * @return list<ShareRecipientSearchResult>
+	 */
+	public function searchRecipients(string $query, int $limit, int $offset): array;
+}

apps/sharing/lib/Model/IShareSourceType.php

@@ -0,0 +1,34 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+namespace OCA\Sharing\Model;
+
+use OCP\IUser;
+
+interface IShareSourceType {
+	/**
+	 * Returns a user friendly display name for this source type.
+	 *
+	 * @return non-empty-string
+	 */
+	public function getDisplayName(): string;
+
+	/*
+	 * Validate that a source exists.
+	 *
+	 * @param non-empty-string $source
+	 */
+	public function validateSource(IUser $owner, string $source): bool;
+
+	/**
+	 * @param non-empty-string $source
+	 * @return ?non-empty-string
+	 */
+	public function getSourceDisplayName(string $source): ?string;
+}

apps/sharing/lib/Model/Share.php

@@ -0,0 +1,178 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+namespace OCA\Sharing\Model;
+
+use OCA\Sharing\Exception\ShareInvalidException;
+use OCA\Sharing\Exception\ShareInvalidPropertiesException;
+use OCA\Sharing\Registry;
+use OCA\Sharing\ResponseDefinitions;
+use OCP\Server;
+
+/**
+ * @psalm-import-type SharingShare from ResponseDefinitions
+ */
+readonly class Share {
+	public function __construct(
+		/** @var non-empty-string $id */
+		public string $id,
+		public ShareOwner $owner,
+		/** @var non-empty-list<ShareSource> $sources */
+		public array $sources,
+		/** @var non-empty-list<ShareRecipient> $recipients */
+		public array $recipients,
+		/** @var array<class-string<IShareFeature>, array<string, non-empty-list<string>>> */
+		public array $properties,
+		/** @var non-negative-int $lastUpdated Unix time in milliseconds */
+		public int $lastUpdated,
+	) {
+		// TODO: Some of these might need to be skipped when loading existing shares from the DB
+
+		/** @psalm-suppress DocblockTypeContradiction */
+		if ($id === '') {
+			throw new ShareInvalidException('The id is empty.');
+		}
+
+		/** {@see \OC\Snowflake\Decoder::decode} */
+		if (!ctype_digit($id)) {
+			throw new ShareInvalidException('The ID is not a valid Snowflake ID.');
+		}
+
+		$registry = Server::get(Registry::class);
+
+		/** @psalm-suppress DocblockTypeContradiction */
+		if ($sources === []) {
+			throw new ShareInvalidException('The sources are missing.');
+		}
+
+		if (!array_is_list($sources)) {
+			throw new ShareInvalidException('The sources are not a list.');
+		}
+
+		/** @var array<class-string<IShareSourceType>, bool> $shareSourceTypes */
+		$shareSourceTypes = [];
+		$sourceTypes = $registry->getSourceTypes();
+		foreach ($sources as $source) {
+			if (!isset($sourceTypes[$source->type])) {
+				throw new ShareInvalidException('The source type is not registered: ' . $source->type);
+			}
+
+			if (!$sourceTypes[$source->type]->validateSource($this->owner->getUser(), $source->value)) {
+				throw new ShareInvalidException('The source ' . $source->value . ' for ' . $source->type . ' is not valid.');
+			}
+
+			$shareSourceTypes[$source->type] = true;
+		}
+
+		/** @psalm-suppress DocblockTypeContradiction */
+		if ($recipients === []) {
+			throw new ShareInvalidException('The recipients are missing.');
+		}
+
+		if (!array_is_list($recipients)) {
+			throw new ShareInvalidException('The recipients are not a list.');
+		}
+
+		/** @var array<class-string<IShareRecipientType>, bool> $shareRecipientTypes */
+		$shareRecipientTypes = [];
+		$recipientTypes = $registry->getRecipientTypes();
+		foreach ($recipients as $recipient) {
+			if (!isset($recipientTypes[$recipient->type])) {
+				throw new ShareInvalidException('The recipient type is not registered: ' . $recipient->type);
+			}
+
+			if (!$recipientTypes[$recipient->type]->validateRecipient($recipient->value)) {
+				throw new ShareInvalidException('The recipient ' . $recipient->value . ' for ' . $recipient->type . ' is not valid.');
+			}
+
+			$shareRecipientTypes[$recipient->type] = true;
+		}
+
+		$features = $registry->getFeatures();
+		foreach ($properties as $featureClass => $featureProperties) {
+			/** @psalm-suppress DocblockTypeContradiction */
+			if (!is_string($featureClass)) {
+				throw new ShareInvalidException('The feature is not a string: ' . var_export($featureClass, true));
+			}
+
+			if (!isset($features[$featureClass])) {
+				throw new ShareInvalidException('The feature is not registered: ' . var_export($featureClass, true));
+			}
+
+			foreach ($features[$featureClass]->getCompatibles() as $compatible) {
+				if (!isset($shareSourceTypes[$compatible['source_type']], $shareRecipientTypes[$compatible['recipient_type']])) {
+					throw new ShareInvalidException('The feature is not compatible with the source types and/or recipient types of the share: ' . var_export($featureClass, true));
+				}
+			}
+
+			/** @psalm-suppress DocblockTypeContradiction */
+			if (!is_array($featureProperties)) {
+				throw new ShareInvalidException('The feature properties are not an array: ' . var_export($featureProperties, true));
+			}
+
+			foreach ($featureProperties as $key => $values) {
+				/** @psalm-suppress DocblockTypeContradiction */
+				if (!is_string($key)) {
+					throw new ShareInvalidException('The feature property key is not a string: ' . var_export($key, true));
+				}
+
+				if (!array_is_list($values)) {
+					throw new ShareInvalidException('The feature property values are not an array: ' . var_export($values, true));
+				}
+
+				foreach ($values as $value) {
+					/** @psalm-suppress DocblockTypeContradiction */
+					if (!is_string($value)) {
+						throw new ShareInvalidException('The feature property value is not a string: ' . var_export($value, true));
+					}
+				}
+			}
+
+			if (!$features[$featureClass]->validateProperties($featureProperties)) {
+				throw new ShareInvalidPropertiesException($featureClass);
+			}
+		}
+	}
+
+	/**
+	 * @param SharingShare $share
+	 */
+	public static function fromArray(array $share): self {
+		return new self(
+			$share['id'],
+			new ShareOwner($share['owner']['user_id'], $share['owner']['display_name'] ?? null),
+			array_map(ShareSource::fromArray(...), $share['sources']),
+			array_map(ShareRecipient::fromArray(...), $share['recipients']),
+			$share['properties'],
+			$share['last_updated'],
+		);
+	}
+
+	/**
+	 * @return SharingShare
+	 */
+	public function toArray(): array {
+		$owner = [
+			'user_id' => $this->owner->userId,
+		];
+
+		if ($this->owner->displayName !== null) {
+			$owner['display_name'] = $this->owner->displayName;
+		}
+
+		return [
+			'id' => $this->id,
+			'owner' => $owner,
+			'last_updated' => $this->lastUpdated,
+			'sources' => array_map(static fn (ShareSource $source): array => $source->toArray(), $this->sources),
+			'recipients' => array_map(static fn (ShareRecipient $recipient): array => $recipient->toArray(), $this->recipients),
+			'properties' => $this->properties,
+		];
+	}
+}

apps/sharing/lib/Model/ShareAccessContext.php

@@ -0,0 +1,32 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+namespace OCA\Sharing\Model;
+
+use OCA\Sharing\Exception\ShareInvalidException;
+use OCP\IUser;
+
+readonly class ShareAccessContext {
+	public function __construct(
+		public ?IUser $currentUser = null,
+		/** @var array<class-string<IShareRecipientType|IShareFeatureFilter>, mixed> $arguments */
+		public array $arguments = [],
+		/**
+		 * Ignore all checks and allow any operation. Only use it for admins and occ.
+		 */
+		public bool $force = false,
+	) {
+		foreach (array_keys($arguments) as $key) {
+			/** @psalm-suppress DocblockTypeContradiction */
+			if (!is_string($key)) {
+				throw new ShareInvalidException('The argument key is not a string: ' . var_export($key, true));
+			}
+		}
+	}
+}

apps/sharing/lib/Model/ShareOwner.php

@@ -0,0 +1,48 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+namespace OCA\Sharing\Model;
+
+use OCA\Sharing\Exception\ShareInvalidException;
+use OCP\IUser;
+use OCP\IUserManager;
+use OCP\Server;
+
+readonly class ShareOwner {
+	private IUser $user;
+
+	public function __construct(
+		/** @var non-empty-string $owner */
+		public string $userId,
+		/** @var ?non-empty-string $ownerDisplayName */
+		public ?string $displayName,
+	) {
+		/** @psalm-suppress DocblockTypeContradiction */
+		if ($this->userId === '') {
+			throw new ShareInvalidException('The userId is empty.');
+		}
+
+		// TODO: Will not work for remote owner
+		$ownerUser = Server::get(IUserManager::class)->get($this->userId);
+		if ($ownerUser === null) {
+			throw new ShareInvalidException('The userId does not exist: ' . $this->userId);
+		}
+
+		$this->user = $ownerUser;
+
+		/** @psalm-suppress DocblockTypeContradiction */
+		if ($displayName === '') {
+			throw new ShareInvalidException('The displayName is empty.');
+		}
+	}
+
+	public function getUser(): IUser {
+		return $this->user;
+	}
+}

apps/sharing/lib/Model/ShareRecipient.php

@@ -0,0 +1,70 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+namespace OCA\Sharing\Model;
+
+use OCA\Sharing\Registry;
+use OCA\Sharing\ResponseDefinitions;
+use OCP\Server;
+use RuntimeException;
+
+/**
+ * @psalm-import-type SharingShareRecipient from ResponseDefinitions
+ */
+readonly class ShareRecipient {
+	public function __construct(
+		/** @var class-string<IShareRecipientType> $type */
+		public string $type,
+		/** @var non-empty-string $value */
+		public string $value,
+		/** @var ?non-empty-string $displayName */
+		public ?string $displayName,
+	) {
+		if (!isset(Server::get(Registry::class)->getRecipientTypes()[$type])) {
+			throw new RuntimeException('The recipient type is not registered: ' . $type);
+		}
+
+		/** @psalm-suppress DocblockTypeContradiction */
+		if ($value === '') {
+			throw new RuntimeException('The value is empty.');
+		}
+
+		/** @psalm-suppress DocblockTypeContradiction */
+		if ($displayName === '') {
+			throw new RuntimeException('The displayName is empty.');
+		}
+	}
+
+	/**
+	 * @param SharingShareRecipient $recipient
+	 */
+	public static function fromArray(array $recipient): self {
+		return new self(
+			$recipient['type'],
+			$recipient['value'],
+			$recipient['display_name'] ?? null,
+		);
+	}
+
+	/**
+	 * @return SharingShareRecipient
+	 */
+	public function toArray(): array {
+		$out = [
+			'type' => $this->type,
+			'value' => $this->value,
+		];
+
+		if ($this->displayName !== null) {
+			$out['display_name'] = $this->displayName;
+		}
+
+		return $out;
+	}
+}

apps/sharing/lib/Model/ShareRecipientSearchResult.php

@@ -0,0 +1,105 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+namespace OCA\Sharing\Model;
+
+use OCA\Sharing\Registry;
+use OCA\Sharing\ResponseDefinitions;
+use OCP\Server;
+use RuntimeException;
+
+/**
+ * @psalm-import-type SharingRecipientSearchResult from ResponseDefinitions
+ */
+class ShareRecipientSearchResult {
+	/** @var ?class-string<IShareRecipientType> $type */
+	private ?string $type = null;
+
+	public function __construct(
+		/** @var non-empty-string $value */
+		readonly public string $value,
+		/** @var non-empty-string $displayName */
+		readonly public string $displayName,
+		/** @var ?non-empty-string $displayNameUnique */
+		readonly public ?string $displayNameUnique,
+		/** @var ?non-empty-string $iconUrlLight */
+		readonly public ?string $iconUrlLight,
+		/** @var ?non-empty-string $iconUrlDark */
+		readonly public ?string $iconUrlDark,
+	) {
+		/** @psalm-suppress DocblockTypeContradiction */
+		if ($value === '') {
+			throw new RuntimeException('The value is empty.');
+		}
+
+		/** @psalm-suppress DocblockTypeContradiction */
+		if ($displayName === '') {
+			throw new RuntimeException('The displayName is empty.');
+		}
+
+		/** @psalm-suppress DocblockTypeContradiction */
+		if ($displayNameUnique === '') {
+			throw new RuntimeException('The displayNameUnique is empty.');
+		}
+
+		if ($iconUrlLight !== null && !preg_match('/^https?:\/\//', $iconUrlLight)) {
+			throw new RuntimeException('The iconUrlLight is not a valid absolute URL: ' . $iconUrlLight);
+		}
+
+		if ($iconUrlDark !== null && !preg_match('/^https?:\/\//', $iconUrlDark)) {
+			throw new RuntimeException('The iconUrlDark is not a valid absolute URL: ' . $iconUrlDark);
+		}
+	}
+
+	/**
+	 * @param class-string<IShareRecipientType> $type
+	 */
+	public function setType(string $type): self {
+		if ($this->type !== null) {
+			throw new RuntimeException('The type is already set.');
+		}
+
+		if (!isset(Server::get(Registry::class)->getRecipientTypes()[$type])) {
+			throw new RuntimeException('The recipient type is not registered: ' . $type);
+		}
+
+		$this->type = $type;
+
+		return $this;
+	}
+
+	/**
+	 * @return SharingRecipientSearchResult
+	 */
+	public function toArray(): array {
+		if ($this->type === null) {
+			throw new RuntimeException('The type has not been set.');
+		}
+
+		$out = [
+			'type' => $this->type,
+			'value' => $this->value,
+			'display_name' => $this->displayName,
+		];
+
+		if ($this->displayNameUnique !== null) {
+			$out['display_name_unique'] = $this->displayNameUnique;
+		}
+
+		if ($this->iconUrlLight !== null) {
+			$out['icon_url_light'] = $this->iconUrlLight;
+		}
+
+		if ($this->iconUrlDark !== null) {
+			$out['icon_url_dark'] = $this->iconUrlDark;
+		}
+
+		return $out;
+	}
+}

apps/sharing/lib/Model/ShareSource.php

@@ -0,0 +1,70 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+namespace OCA\Sharing\Model;
+
+use OCA\Sharing\Registry;
+use OCA\Sharing\ResponseDefinitions;
+use OCP\Server;
+use RuntimeException;
+
+/**
+ * @psalm-import-type SharingShareSource from ResponseDefinitions
+ */
+readonly class ShareSource {
+	public function __construct(
+		/** @var class-string<IShareSourceType> $type */
+		public string $type,
+		/** @var non-empty-string $value */
+		public string $value,
+		/** @var ?non-empty-string $displayName */
+		public ?string $displayName,
+	) {
+		if (!isset(Server::get(Registry::class)->getSourceTypes()[$type])) {
+			throw new RuntimeException('The source type is not registered: ' . $type);
+		}
+
+		/** @psalm-suppress DocblockTypeContradiction */
+		if ($value === '') {
+			throw new RuntimeException('The value is empty.');
+		}
+
+		/** @psalm-suppress DocblockTypeContradiction */
+		if ($displayName === '') {
+			throw new RuntimeException('The displayName is empty.');
+		}
+	}
+
+	/**
+	 * @param SharingShareSource $source
+	 */
+	public static function fromArray(array $source): self {
+		return new self(
+			$source['type'],
+			$source['value'],
+			$source['display_name'] ?? null,
+		);
+	}
+
+	/**
+	 * @return SharingShareSource
+	 */
+	public function toArray(): array {
+		$out = [
+			'type' => $this->type,
+			'value' => $this->value,
+		];
+
+		if ($this->displayName !== null) {
+			$out['display_name'] = $this->displayName;
+		}
+
+		return $out;
+	}
+}

apps/sharing/lib/Registry.php

@@ -0,0 +1,83 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+namespace OCA\Sharing;
+
+use OCA\Sharing\Model\IShareFeature;
+use OCA\Sharing\Model\IShareRecipientType;
+use OCA\Sharing\Model\IShareSourceType;
+use RuntimeException;
+
+class Registry {
+	/** @var array<class-string<IShareSourceType>, IShareSourceType> */
+	private array $sourceTypes = [];
+
+	/** @var array<class-string<IShareRecipientType>, IShareRecipientType> */
+	private array $recipientTypes = [];
+
+	/** @var array<class-string<IShareFeature>, IShareFeature> */
+	private array $features = [];
+
+	public function clear(): void {
+		$this->sourceTypes = [];
+		$this->recipientTypes = [];
+		$this->features = [];
+	}
+
+	public function registerSourceType(IShareSourceType $sourceType): void {
+		$class = $sourceType::class;
+
+		if (isset($this->sourceTypes[$class])) {
+			throw new RuntimeException('Share source type ' . $class . ' is already registered');
+		}
+
+		$this->sourceTypes[$class] = $sourceType;
+	}
+
+	public function registerRecipientType(IShareRecipientType $recipientType): void {
+		$class = $recipientType::class;
+
+		if (isset($this->recipientTypes[$class])) {
+			throw new RuntimeException('Share recipient type ' . $class . ' is already registered');
+		}
+
+		$this->recipientTypes[$class] = $recipientType;
+	}
+
+	public function registerFeature(IShareFeature $feature): void {
+		$class = $feature::class;
+
+		if (isset($this->features[$class])) {
+			throw new RuntimeException('Share feature ' . $class . ' is already registered');
+		}
+
+		$this->features[$class] = $feature;
+	}
+
+	/**
+	 * @return array<class-string<IShareSourceType>, IShareSourceType>
+	 */
+	public function getSourceTypes(): array {
+		return $this->sourceTypes;
+	}
+
+	/**
+	 * @return array<class-string<IShareRecipientType>, IShareRecipientType>
+	 */
+	public function getRecipientTypes(): array {
+		return $this->recipientTypes;
+	}
+
+	/**
+	 * @return array<class-string<IShareFeature>, IShareFeature>
+	 */
+	public function getFeatures(): array {
+		return $this->features;
+	}
+}

apps/sharing/lib/ResponseDefinitions.php

@@ -0,0 +1,72 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+namespace OCA\Sharing;
+
+use OCA\Sharing\Model\IShareFeature;
+use OCA\Sharing\Model\IShareRecipientType;
+use OCA\Sharing\Model\IShareSourceType;
+
+/**
+ * @psalm-type SharingShareSource = array{
+ *     type: class-string<IShareSourceType>,
+ *     value: non-empty-string,
+ *     // Will be set by the server automatically
+ *     display_name?: non-empty-string,
+ * }
+ *
+ * @psalm-type SharingShareRecipient = array{
+ *     type: class-string<IShareRecipientType>,
+ *     value: non-empty-string,
+ *     // Will be set by the server automatically
+ *     display_name?: non-empty-string,
+ * }
+ *
+ * @psalm-type SharingShareOwner = array{
+ *     user_id: non-empty-string,
+ *     // Will be set by the server automatically
+ *     display_name?: non-empty-string,
+ * }
+ *
+ * @psalm-type SharingPartialShare = array{
+ *     owner: SharingShareOwner,
+ *     sources: non-empty-list<SharingShareSource>,
+ *     recipients: non-empty-list<SharingShareRecipient>,
+ *     properties: array<class-string<IShareFeature>, array<string, non-empty-list<string>>>,
+ * }
+ *
+ * @psalm-type SharingShare = SharingPartialShare&array{
+ *     id: non-empty-string,
+ *     // Unix time in milliseconds
+ *     last_updated: non-negative-int,
+ * }
+ *
+ * @psalm-type SharingCompatible = array{
+ *     source_type: class-string<IShareSourceType>,
+ *     recipient_type: class-string<IShareRecipientType>,
+ * }
+ *
+ * @psalm-type SharingFeature = array{
+ *     compatibles: non-empty-list<SharingCompatible>,
+ * }
+ *
+ * @psalm-type SharingRecipientSearchResult = array{
+ *     type: class-string<IShareRecipientType>,
+ *     value: non-empty-string,
+ *     display_name: non-empty-string,
+ *     // If multiple search results with the same display_name are returned, also show this display_name_unique.
+ *     display_name_unique?: non-empty-string,
+ *     // Absolute URL
+ *     icon_url_light?: non-empty-string,
+ *     // Absolute URL
+ *     icon_url_dark?: non-empty-string,
+ * }
+ */
+class ResponseDefinitions {
+}

apps/sharing/tests/AbstractApiTests.php

@@ -0,0 +1,278 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+namespace OCA\Sharing\Tests;
+
+use OCA\Sharing\Exception\ShareNotFoundException;
+use OCA\Sharing\Manager;
+use OCA\Sharing\Model\Share;
+use OCA\Sharing\Model\ShareAccessContext;
+use OCA\Sharing\Registry;
+use OCA\Sharing\ResponseDefinitions;
+use OCP\IUser;
+use OCP\IUserManager;
+use OCP\Server;
+use PHPUnit\Framework\Attributes\Group;
+use Test\TestCase;
+
+/**
+ * @psalm-import-type SharingShare from ResponseDefinitions
+ * @psalm-import-type SharingPartialShare from ResponseDefinitions
+ */
+#[Group(name: 'DB')]
+abstract class AbstractApiTests extends TestCase {
+	private Manager $manager;
+
+	protected Registry $registry;
+
+	protected IUser $owner1;
+
+	protected IUser $owner2;
+
+
+	public function setUp(): void {
+		parent::setUp();
+
+		$this->manager = Server::get(Manager::class);
+
+		$this->registry = Server::get(Registry::class);
+
+		$owner1 = Server::get(IUserManager::class)->createUser('owner1', 'password');
+		$this->assertNotFalse($owner1);
+		$this->owner1 = $owner1;
+		$this->owner1->setDisplayName('Owner 1');
+
+		$owner2 = Server::get(IUserManager::class)->createUser('owner2', 'password');
+		$this->assertNotFalse($owner2);
+		$this->owner2 = $owner2;
+		$this->owner2->setDisplayName('Owner 2');
+	}
+
+	protected function tearDown(): void {
+		foreach ($this->manager->list(new ShareAccessContext(force: true), null, null, null) as $share) {
+			$this->manager->delete(new ShareAccessContext(force: true), $share->id);
+		}
+
+		$this->registry->clear();
+
+		$this->owner1->delete();
+		$this->owner2->delete();
+
+		parent::tearDown();
+	}
+
+	private function register(): void {
+		$this->registry->registerSourceType(new TestShareSourceType(['source1' => 'Source 1']));
+		$this->registry->registerSourceType(new TestShareSourceType2(['source2' => 'Source 2']));
+		$this->registry->registerRecipientType(new TestShareRecipientType(['recipient1' => 'Recipient 1'], [], []));
+		$this->registry->registerRecipientType(new TestShareRecipientType2(['recipient2' => 'Recipient 2'], [], []));
+		$this->registry->registerFeature(new TestShareFeature([['source_type' => TestShareSourceType::class, 'recipient_type' => TestShareRecipientType::class]], ['key1']));
+		$this->registry->registerFeature(new TestShareFeature2([['source_type' => TestShareSourceType2::class, 'recipient_type' => TestShareRecipientType2::class]], ['key2']));
+	}
+
+	/**
+	 * @return SharingPartialShare
+	 */
+	private function getShareData(): array {
+		return [
+			'owner' => [
+				'user_id' => 'owner1',
+			],
+			'sources' => [
+				[
+					'type' => TestShareSourceType::class,
+					'value' => 'source1',
+				],
+				[
+					'type' => TestShareSourceType2::class,
+					'value' => 'source2',
+				],
+			],
+			'recipients' => [
+				[
+					'type' => TestShareRecipientType::class,
+					'value' => 'recipient1',
+				],
+				[
+					'type' => TestShareRecipientType2::class,
+					'value' => 'recipient2',
+				],
+			],
+			'properties' => [
+				TestShareFeature::class => [
+					'key1' => ['value1'],
+				],
+				TestShareFeature2::class => [
+					'key2' => ['value2'],
+				],
+			],
+		];
+	}
+
+	/**
+	 * @return SharingPartialShare
+	 */
+	private function getShareDataWithDisplayNames(): array {
+		return [
+			'owner' => [
+				'user_id' => 'owner1',
+				'display_name' => 'Owner 1',
+			],
+			'sources' => [
+				[
+					'type' => TestShareSourceType::class,
+					'value' => 'source1',
+					'display_name' => 'Source 1',
+				],
+				[
+					'type' => TestShareSourceType2::class,
+					'value' => 'source2',
+					'display_name' => 'Source 2',
+				],
+			],
+			'recipients' => [
+				[
+					'type' => TestShareRecipientType::class,
+					'value' => 'recipient1',
+					'display_name' => 'Recipient 1',
+				],
+				[
+					'type' => TestShareRecipientType2::class,
+					'value' => 'recipient2',
+					'display_name' => 'Recipient 2',
+				],
+			],
+			'properties' => [
+				TestShareFeature::class => [
+					'key1' => ['value1'],
+				],
+				TestShareFeature2::class => [
+					'key2' => ['value2'],
+				],
+			],
+		];
+	}
+
+	/**
+	 * @param SharingPartialShare $data
+	 * @return SharingShare
+	 */
+	abstract protected function createShare(array $data): array;
+
+	public function testCreateShare(): void {
+		$this->register();
+
+		$data = $this->getShareData();
+		$response = $this->createShare($data);
+		$this->assertArrayHasKey('id', $response);
+		unset($response['id']);
+		$this->assertArrayHasKey('last_updated', $response);
+		unset($response['last_updated']);
+		$this->assertEquals($this->getShareDataWithDisplayNames(), $response);
+	}
+
+	/**
+	 * @param non-empty-string $shareID
+	 * @return SharingShare
+	 */
+	abstract protected function getShare(string $shareID): array;
+
+	public function testGetShare(): void {
+		$this->register();
+
+		$data = $this->manager->completePartialShareData($this->getShareData());
+		$this->manager->insert(Share::fromArray($data));
+
+		$response = $this->getShare($data['id']);
+		$this->assertArrayHasKey('id', $response);
+		unset($response['id']);
+		$this->assertArrayHasKey('last_updated', $response);
+		unset($response['last_updated']);
+		$this->assertEquals($this->getShareDataWithDisplayNames(), $response);
+	}
+
+	/**
+	 * @param non-empty-string $shareID
+	 */
+	abstract protected function deleteShare(string $shareID): void;
+
+	public function testDeleteShare(): void {
+		$this->register();
+
+		$data = $this->manager->completePartialShareData($this->getShareData());
+		$this->manager->insert(Share::fromArray($data));
+
+		$this->deleteShare($data['id']);
+
+		$this->expectException(ShareNotFoundException::class);
+		$this->manager->get(new ShareAccessContext(force: true), $data['id']);
+	}
+
+	/**
+	 * @param SharingShare $data
+	 * @return SharingShare
+	 */
+	abstract protected function updateShare(array $data): array;
+
+	public function testUpdateShare(): void {
+		$this->register();
+
+		$data = [
+			'owner' => [
+				'user_id' => $this->owner1->getUID(),
+			],
+			'sources' => [['type' => TestShareSourceType::class, 'value' => 'source1']],
+			'recipients' => [['type' => TestShareRecipientType::class, 'value' => 'recipient1']],
+			'properties' => [TestShareFeature::class => ['key1' => ['key1']]],
+		];
+		$data = $this->manager->completePartialShareData($data);
+
+		$this->manager->insert(Share::fromArray($data));
+		$response = $this->manager->get(new ShareAccessContext(force: true), $data['id'])->toArray();
+		$this->assertArrayHasKey('last_updated', $response);
+		$lastUpdated = $response['last_updated'];
+
+		$data['owner'] = ['user_id' => $this->owner2->getUID()];
+		$data['sources'] = [['type' => TestShareSourceType2::class, 'value' => 'source2']];
+		$data['recipients'] = [['type' => TestShareRecipientType2::class, 'value' => 'recipient2']];
+		$data['properties'] = [TestShareFeature2::class => ['key2' => ['value2']]];
+		$response = $this->updateShare($data);
+		$this->assertArrayHasKey('id', $response);
+		unset($response['id']);
+		$this->assertArrayHasKey('last_updated', $response);
+		$this->assertGreaterThan($lastUpdated, $response['last_updated']);
+		unset($response['last_updated']);
+
+		$this->assertEquals([
+			'owner' => [
+				'user_id' => 'owner2',
+				'display_name' => 'Owner 2',
+			],
+			'sources' => [
+				[
+					'type' => TestShareSourceType2::class,
+					'value' => 'source2',
+					'display_name' => 'Source 2',
+				],
+			],
+			'recipients' => [
+				[
+					'type' => TestShareRecipientType2::class,
+					'value' => 'recipient2',
+					'display_name' => 'Recipient 2',
+				],
+			],
+			'properties' => [
+				TestShareFeature2::class => [
+					'key2' => ['value2'],
+				],
+			],
+		], $response);
+	}
+}

apps/sharing/tests/CapabilitiesTest.php

@@ -0,0 +1,85 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+
+use OCA\Sharing\AppInfo\Application;
+use OCA\Sharing\Capabilities;
+use OCA\Sharing\Registry;
+use OCA\Sharing\Tests\TestShareFeature;
+use OCA\Sharing\Tests\TestShareFeature2;
+use OCA\Sharing\Tests\TestShareRecipientType;
+use OCA\Sharing\Tests\TestShareRecipientType2;
+use OCA\Sharing\Tests\TestShareSourceType;
+use OCA\Sharing\Tests\TestShareSourceType2;
+use OCP\Server;
+use Test\TestCase;
+
+class CapabilitiesTest extends TestCase {
+	private Registry $registry;
+
+	private Capabilities $capabilities;
+
+	public function setUp(): void {
+		parent::setUp();
+
+		$this->registry = Server::get(Registry::class);
+
+		$this->capabilities = Server::get(Capabilities::class);
+	}
+
+	protected function tearDown(): void {
+		$this->registry->clear();
+
+		parent::tearDown();
+	}
+
+	public function testGetCapabilities(): void {
+		$this->registry->registerSourceType(new TestShareSourceType([]));
+		$this->registry->registerSourceType(new TestShareSourceType2([]));
+		$this->registry->registerRecipientType(new TestShareRecipientType([], [], []));
+		$this->registry->registerRecipientType(new TestShareRecipientType2([], [], []));
+		$this->registry->registerFeature(new TestShareFeature([['source_type' => TestShareSourceType::class, 'recipient_type' => TestShareRecipientType::class]], []));
+		$this->registry->registerFeature(new TestShareFeature2([['source_type' => TestShareSourceType2::class, 'recipient_type' => TestShareRecipientType2::class]], []));
+
+		$this->assertEquals(
+			[
+				Application::APP_ID => [
+					'api_versions' => ['v1'],
+					'source_types' => [
+						TestShareSourceType::class => 'TestShareSourceType',
+						TestShareSourceType2::class => 'TestShareSourceType2',
+					],
+					'recipient_types' => [
+						TestShareRecipientType::class => 'TestShareRecipientType',
+						TestShareRecipientType2::class => 'TestShareRecipientType2',
+					],
+					'features' => [
+						TestShareFeature::class => [
+							'compatibles' => [
+								[
+									'source_type' => TestShareSourceType::class,
+									'recipient_type' => TestShareRecipientType::class,
+								],
+							],
+						],
+						TestShareFeature2::class => [
+							'compatibles' => [
+								[
+									'source_type' => TestShareSourceType2::class,
+									'recipient_type' => TestShareRecipientType2::class,
+								],
+							],
+						],
+					],
+				],
+			],
+			$this->capabilities->getCapabilities(),
+		);
+	}
+}

apps/sharing/tests/Command/CommandTest.php

@@ -0,0 +1,104 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+use OCA\Sharing\Command\Create;
+use OCA\Sharing\Command\Delete;
+use OCA\Sharing\Command\Get;
+use OCA\Sharing\Command\Update;
+use OCA\Sharing\ResponseDefinitions;
+use OCA\Sharing\Tests\AbstractApiTests;
+use OCP\Server;
+use PHPUnit\Framework\Attributes\Group;
+use PHPUnit\Framework\MockObject\MockObject;
+use Symfony\Component\Console\Input\Input;
+use Symfony\Component\Console\Output\Output;
+
+/**
+ * @psalm-import-type SharingShare from ResponseDefinitions
+ */
+#[Group(name: 'DB')]
+class CommandTest extends AbstractApiTests {
+	private Input&MockObject $input;
+
+	private Output&MockObject $output;
+
+	private string $stdout = '';
+
+	public function setUp(): void {
+		parent::setUp();
+
+		$this->input = $this->createMock(Input::class);
+
+		$this->output = $this->createMock(Output::class);
+		$this->output
+			->method('writeln')
+			->willReturnCallback(function (string $message): void {
+				$this->stdout .= $message . "\n";
+			});
+	}
+
+	protected function createShare(array $data): array {
+		$this->input
+			->expects($this->once())
+			->method('getArgument')
+			->with('data')
+			->willReturn(json_encode($data, JSON_THROW_ON_ERROR));
+
+		$exitCode = Server::get(Create::class)->execute($this->input, $this->output);
+		$this->assertEquals(0, $exitCode);
+
+		/** @var SharingShare $out */
+		$out = json_decode($this->stdout, true, 512, JSON_THROW_ON_ERROR);
+
+		return $out;
+	}
+
+	protected function getShare(string $shareID): array {
+		$this->input
+			->expects($this->once())
+			->method('getArgument')
+			->with('id')
+			->willReturn($shareID);
+
+		$exitCode = Server::get(Get::class)->execute($this->input, $this->output);
+		$this->assertEquals(0, $exitCode);
+
+		/** @var SharingShare $out */
+		$out = json_decode($this->stdout, true, 512, JSON_THROW_ON_ERROR);
+
+		return $out;
+	}
+
+	protected function deleteShare(string $shareID): void {
+		$this->input
+			->expects($this->once())
+			->method('getArgument')
+			->with('id')
+			->willReturn($shareID);
+
+		$exitCode = Server::get(Delete::class)->execute($this->input, $this->output);
+		$this->assertEquals(0, $exitCode);
+	}
+
+	protected function updateShare(array $data): array {
+		$this->input
+			->expects($this->once())
+			->method('getArgument')
+			->with('data')
+			->willReturn(json_encode($data, JSON_THROW_ON_ERROR));
+
+		$exitCode = Server::get(Update::class)->execute($this->input, $this->output);
+		$this->assertEquals(0, $exitCode);
+
+		/** @var SharingShare $out */
+		$out = json_decode($this->stdout, true, 512, JSON_THROW_ON_ERROR);
+
+		return $out;
+	}
+}

apps/sharing/tests/Controller/ApiV1ControllerTest.php

@@ -0,0 +1,534 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+use OCA\Sharing\Controller\ApiV1Controller;
+use OCA\Sharing\Model\ShareRecipientSearchResult;
+use OCA\Sharing\ResponseDefinitions;
+use OCA\Sharing\Tests\AbstractApiTests;
+use OCA\Sharing\Tests\TestShareFeature;
+use OCA\Sharing\Tests\TestShareFeature2;
+use OCA\Sharing\Tests\TestShareFeatureFilter;
+use OCA\Sharing\Tests\TestShareFeatureModifyProperties;
+use OCA\Sharing\Tests\TestShareRecipientType;
+use OCA\Sharing\Tests\TestShareRecipientType2;
+use OCA\Sharing\Tests\TestShareRecipientTypeArguments;
+use OCA\Sharing\Tests\TestShareSourceType;
+use OCA\Sharing\Tests\TestShareSourceType2;
+use OCP\AppFramework\Http;
+use OCP\Server;
+use PHPUnit\Framework\Attributes\Group;
+
+/**
+ * The abstract tests are executed as the owner, allowing all operations.
+ *
+ * @psalm-import-type SharingShare from ResponseDefinitions
+ */
+#[Group(name: 'DB')]
+class ApiV1ControllerTest extends AbstractApiTests {
+	private ApiV1Controller $controller;
+
+	public function setUp(): void {
+		parent::setUp();
+
+		self::loginAsUser($this->owner1->getUID());
+
+		$this->controller = Server::get(ApiV1Controller::class);
+	}
+
+	protected function createShare(array $data): array {
+		$response = $this->controller->createShare($data);
+		/** @var SharingShare $responseData */
+		$responseData = $response->getData();
+		$this->assertEquals(Http::STATUS_CREATED, $response->getStatus(), var_export($responseData, true));
+		return $responseData;
+	}
+
+	protected function getShare(string $shareID): array {
+		$response = $this->controller->getShare($shareID);
+		/** @var SharingShare $responseData */
+		$responseData = $response->getData();
+		$this->assertEquals(Http::STATUS_OK, $response->getStatus(), var_export($responseData, true));
+		return $responseData;
+	}
+
+	protected function deleteShare(string $shareID): void {
+		$response = $this->controller->deleteShare($shareID);
+		$responseData = $response->getData();
+		$this->assertEquals(Http::STATUS_NO_CONTENT, $response->getStatus(), var_export($responseData, true));
+	}
+
+	protected function updateShare(array $data): array {
+		$response = $this->controller->updateShare($data['id'], $data);
+		/** @var SharingShare $responseData */
+		$responseData = $response->getData();
+		$this->assertEquals(Http::STATUS_OK, $response->getStatus(), var_export($responseData, true));
+		return $responseData;
+	}
+
+	public function testSearchRecipients(): void {
+		$displayNames = [
+			'recipient1a' => 'Recipient 1A',
+			'recipient1b' => 'Recipient 1B',
+			'recipient1c' => 'Recipient 1C',
+			'recipient2a' => 'Recipient 2A',
+			'recipient2b' => 'Recipient 2B',
+			'recipient2c' => 'Recipient 2C',
+		];
+
+		$recipient1a = new ShareRecipientSearchResult('recipient1a', $displayNames['recipient1a'], null, null, null);
+		$recipient1b = new ShareRecipientSearchResult('recipient1b', $displayNames['recipient1b'], null, null, null);
+		$recipient1c = new ShareRecipientSearchResult('recipient1c', $displayNames['recipient1c'], null, null, null);
+		$recipient2a = new ShareRecipientSearchResult('recipient2a', $displayNames['recipient2a'], null, null, null);
+		$recipient2b = new ShareRecipientSearchResult('recipient2b', $displayNames['recipient2b'], null, null, null);
+		$recipient2c = new ShareRecipientSearchResult('recipient2c', $displayNames['recipient2c'], null, null, null);
+
+		$this->registry->registerRecipientType(new TestShareRecipientType([], [], [$recipient1a, $recipient1b, $recipient1c]));
+		$this->registry->registerRecipientType(new TestShareRecipientType2([], [], [$recipient2a, $recipient2b, $recipient2c]));
+
+		$response = $this->controller->searchRecipients(null, 'recipient');
+		$responseData = $response->getData();
+		$this->assertEquals(Http::STATUS_OK, $response->getStatus(), var_export($responseData, true));
+		$this->assertEquals([
+			['type' => TestShareRecipientType::class, 'value' => 'recipient1a', 'display_name' => $displayNames['recipient1a']],
+			['type' => TestShareRecipientType::class, 'value' => 'recipient1b', 'display_name' => $displayNames['recipient1b']],
+			['type' => TestShareRecipientType::class, 'value' => 'recipient1c', 'display_name' => $displayNames['recipient1c']],
+			['type' => TestShareRecipientType2::class, 'value' => 'recipient2a', 'display_name' => $displayNames['recipient2a']],
+			['type' => TestShareRecipientType2::class, 'value' => 'recipient2b', 'display_name' => $displayNames['recipient2b']],
+			['type' => TestShareRecipientType2::class, 'value' => 'recipient2c', 'display_name' => $displayNames['recipient2c']],
+		], $responseData);
+
+		$response = $this->controller->searchRecipients(TestShareRecipientType::class, 'recipient');
+		$responseData = $response->getData();
+		$this->assertEquals(Http::STATUS_OK, $response->getStatus(), var_export($responseData, true));
+		$this->assertEquals([
+			['type' => TestShareRecipientType::class, 'value' => 'recipient1a', 'display_name' => $displayNames['recipient1a']],
+			['type' => TestShareRecipientType::class, 'value' => 'recipient1b', 'display_name' => $displayNames['recipient1b']],
+			['type' => TestShareRecipientType::class, 'value' => 'recipient1c', 'display_name' => $displayNames['recipient1c']],
+		], $responseData);
+
+		$response = $this->controller->searchRecipients(TestShareRecipientType::class, 'recipient', 1);
+		$responseData = $response->getData();
+		$this->assertEquals(Http::STATUS_OK, $response->getStatus(), var_export($responseData, true));
+		$this->assertEquals([
+			['type' => TestShareRecipientType::class, 'value' => 'recipient1a', 'display_name' => $displayNames['recipient1a']],
+		], $responseData);
+
+		$response = $this->controller->searchRecipients(TestShareRecipientType::class, 'recipient', offset: 1);
+		$responseData = $response->getData();
+		$this->assertEquals(Http::STATUS_OK, $response->getStatus(), var_export($responseData, true));
+		$this->assertEquals([
+			['type' => TestShareRecipientType::class, 'value' => 'recipient1b', 'display_name' => $displayNames['recipient1b']],
+			['type' => TestShareRecipientType::class, 'value' => 'recipient1c', 'display_name' => $displayNames['recipient1c']],
+		], $responseData);
+
+		/** @psalm-suppress ArgumentTypeCoercion */
+		$response = $this->controller->searchRecipients('abc', 'recipient');
+		$responseData = $response->getData();
+		$this->assertEquals(Http::STATUS_BAD_REQUEST, $response->getStatus(), var_export($responseData, true));
+		$this->assertEquals('Invalid operation parameter: The recipient type is not registered.', $responseData);
+	}
+
+	public function testCreateShareModifyProperties(): void {
+		$this->registry->registerSourceType(new TestShareSourceType(['source' => 'Source']));
+		$this->registry->registerRecipientType(new TestShareRecipientType(['recipient1' => 'Recipient 1', 'recipient2' => 'Recipient 2'], ['recipient1'], []));
+		$this->registry->registerFeature(new TestShareFeatureModifyProperties([['source_type' => TestShareSourceType::class, 'recipient_type' => TestShareRecipientType::class]]));
+
+		$data = [
+			'owner' => [
+				'user_id' => $this->owner1->getUID(),
+				'display_name' => $this->owner1->getDisplayName(),
+			],
+			'sources' => [['type' => TestShareSourceType::class, 'value' => 'source', 'display_name' => 'Source']],
+			'recipients' => [['type' => TestShareRecipientType::class, 'value' => 'recipient1', 'display_name' => 'Recipient 1'], ['type' => TestShareRecipientType::class, 'value' => 'recipient2', 'display_name' => 'Recipient 2']],
+			'properties' => [TestShareFeatureModifyProperties::class => ['before' => ['valid']]],
+		];
+		$response = $this->controller->createShare($data);
+		/** @var SharingShare $responseData */
+		$responseData = $response->getData();
+		$this->assertEquals(Http::STATUS_CREATED, $response->getStatus(), var_export($responseData, true));
+		$this->assertArrayHasKey('id', $responseData);
+		$this->assertEquals([TestShareFeatureModifyProperties::class => ['after' => ['valid']]], $responseData['properties']);
+	}
+
+	public function testGetShareAsRecipient(): void {
+		$this->registry->registerSourceType(new TestShareSourceType(['source' => 'Source']));
+		$this->registry->registerRecipientType(new TestShareRecipientType(['recipient1' => 'Recipient 1', 'recipient2' => 'Recipient 2'], ['recipient1'], []));
+		$this->registry->registerFeature(new TestShareFeature([['source_type' => TestShareSourceType::class, 'recipient_type' => TestShareRecipientType::class]], ['key']));
+
+		$data = [
+			'owner' => [
+				'user_id' => $this->owner1->getUID(),
+				'display_name' => $this->owner1->getDisplayName(),
+			],
+			'sources' => [['type' => TestShareSourceType::class, 'value' => 'source', 'display_name' => 'Source']],
+			'recipients' => [['type' => TestShareRecipientType::class, 'value' => 'recipient1', 'display_name' => 'Recipient 1'], ['type' => TestShareRecipientType::class, 'value' => 'recipient2', 'display_name' => 'Recipient 2']],
+			'properties' => [TestShareFeature::class => ['key' => ['value']]],
+		];
+		$response = $this->controller->createShare($data);
+		/** @var SharingShare $responseData */
+		$responseData = $response->getData();
+		$this->assertEquals(Http::STATUS_CREATED, $response->getStatus(), var_export($responseData, true));
+		$this->assertArrayHasKey('id', $responseData);
+		$id = $responseData['id'];
+		unset($responseData['id']);
+		$this->assertArrayHasKey('last_updated', $responseData);
+		unset($responseData['last_updated']);
+		$this->assertEquals($data, $responseData);
+
+		self::logout();
+
+		$response = $this->controller->getShare($id);
+		/** @var SharingShare $responseData */
+		$responseData = $response->getData();
+		$this->assertEquals(Http::STATUS_OK, $response->getStatus(), var_export($responseData, true));
+		$this->assertArrayHasKey('id', $responseData);
+		unset($responseData['id']);
+		$this->assertArrayHasKey('last_updated', $responseData);
+		unset($responseData['last_updated']);
+		$this->assertEquals($data, $responseData);
+	}
+
+	public function testGetShareAsRecipientWithRecipientArguments(): void {
+		$this->registry->registerSourceType(new TestShareSourceType(['source' => 'Source']));
+		$this->registry->registerRecipientType(new TestShareRecipientTypeArguments());
+
+		$data = [
+			'owner' => [
+				'user_id' => $this->owner1->getUID(),
+				'display_name' => $this->owner1->getDisplayName(),
+			],
+			'sources' => [['type' => TestShareSourceType::class, 'value' => 'source', 'display_name' => 'Source']],
+			'recipients' => [['type' => TestShareRecipientTypeArguments::class, 'value' => 'secret', 'display_name' => 'secret']],
+			'properties' => [],
+		];
+		$response = $this->controller->createShare($data);
+		/** @var SharingShare $responseData */
+		$responseData = $response->getData();
+		$this->assertEquals(Http::STATUS_CREATED, $response->getStatus(), var_export($responseData, true));
+		$this->assertArrayHasKey('id', $responseData);
+		$id = $responseData['id'];
+		unset($responseData['id']);
+		$this->assertArrayHasKey('last_updated', $responseData);
+		unset($responseData['last_updated']);
+		$this->assertEquals($data, $responseData);
+
+		self::logout();
+
+		$response = $this->controller->getShare($id);
+		$responseData = $response->getData();
+		$this->assertEquals(Http::STATUS_NOT_FOUND, $response->getStatus(), var_export($responseData, true));
+		$this->assertEquals('Share ' . $id . ' not found.', $responseData);
+
+		$response = $this->controller->getShare($id, [TestShareRecipientTypeArguments::class => 'secret']);
+		/** @var SharingShare $responseData */
+		$responseData = $response->getData();
+		$this->assertEquals(Http::STATUS_OK, $response->getStatus(), var_export($responseData, true));
+		$this->assertArrayHasKey('id', $responseData);
+		unset($responseData['id']);
+		$this->assertArrayHasKey('last_updated', $responseData);
+		unset($responseData['last_updated']);
+		$this->assertEquals($data, $responseData);
+	}
+
+	public function testGetShareAsNonRecipient(): void {
+		$this->registry->registerSourceType(new TestShareSourceType(['source' => 'Source']));
+		$this->registry->registerRecipientType(new TestShareRecipientType(['recipient' => 'Recipient'], [], []));
+		$this->registry->registerFeature(new TestShareFeature([['source_type' => TestShareSourceType::class, 'recipient_type' => TestShareRecipientType::class]], ['key']));
+
+		$data = [
+			'owner' => [
+				'user_id' => $this->owner1->getUID(),
+				'display_name' => $this->owner1->getDisplayName(),
+			],
+			'sources' => [['type' => TestShareSourceType::class, 'value' => 'source', 'display_name' => 'Source']],
+			'recipients' => [['type' => TestShareRecipientType::class, 'value' => 'recipient', 'display_name' => 'Recipient']],
+			'properties' => [TestShareFeature::class => ['key' => ['value']]],
+		];
+		$response = $this->controller->createShare($data);
+		/** @var SharingShare $responseData */
+		$responseData = $response->getData();
+		$this->assertEquals(Http::STATUS_CREATED, $response->getStatus(), var_export($responseData, true));
+		$this->assertArrayHasKey('id', $responseData);
+		$id = $responseData['id'];
+		unset($responseData['id']);
+		$this->assertArrayHasKey('last_updated', $responseData);
+		unset($responseData['last_updated']);
+		$this->assertEquals($data, $responseData);
+
+		self::logout();
+
+		$response = $this->controller->getShare($id);
+		$responseData = $response->getData();
+		$this->assertEquals(Http::STATUS_NOT_FOUND, $response->getStatus(), var_export($responseData, true));
+		$this->assertEquals('Share ' . $id . ' not found.', $responseData);
+	}
+
+	public function testGetShareFilteredProperties(): void {
+		$this->registry->registerSourceType(new TestShareSourceType(['source' => 'Source']));
+		$this->registry->registerRecipientType(new TestShareRecipientType(['recipient' => 'Recipient'], ['recipient'], []));
+		$this->registry->registerFeature(new TestShareFeatureFilter([['source_type' => TestShareSourceType::class, 'recipient_type' => TestShareRecipientType::class]]));
+
+		$data = [
+			'owner' => [
+				'user_id' => $this->owner1->getUID(),
+				'display_name' => $this->owner1->getDisplayName(),
+			],
+			'sources' => [['type' => TestShareSourceType::class, 'value' => 'source', 'display_name' => 'Source']],
+			'recipients' => [['type' => TestShareRecipientType::class, 'value' => 'recipient', 'display_name' => 'Recipient']],
+			'properties' => [TestShareFeatureFilter::class => ['filtered' => ['false']]],
+		];
+		$response = $this->controller->createShare($data);
+		/** @var SharingShare $responseData */
+		$responseData = $response->getData();
+		$this->assertEquals(Http::STATUS_CREATED, $response->getStatus(), var_export($responseData, true));
+		$this->assertArrayHasKey('id', $responseData);
+		$id = $responseData['id'];
+		unset($responseData['id']);
+		$this->assertArrayHasKey('last_updated', $responseData);
+		unset($responseData['last_updated']);
+		$this->assertEquals($data, $responseData);
+
+		self::logout();
+
+		$response = $this->controller->getShare($id);
+		/** @var SharingShare $responseData */
+		$responseData = $response->getData();
+		$this->assertEquals(Http::STATUS_OK, $response->getStatus(), var_export($responseData, true));
+		$this->assertArrayHasKey('id', $responseData);
+		unset($responseData['id']);
+		$this->assertArrayHasKey('last_updated', $responseData);
+		$lastUpdated = $responseData['last_updated'];
+		unset($responseData['last_updated']);
+		$this->assertEquals($data, $responseData);
+
+		self::loginAsUser($this->owner1->getUID());
+
+		$data['id'] = $id;
+		$data['last_updated'] = $lastUpdated;
+		$data['properties'] = [TestShareFeatureFilter::class => ['filtered' => ['true']]];
+		$response = $this->controller->updateShare($id, $data);
+		/** @var SharingShare $responseData */
+		$responseData = $response->getData();
+		$this->assertEquals(Http::STATUS_OK, $response->getStatus(), var_export($responseData, true));
+		$this->assertArrayHasKey('id', $responseData);
+		$this->assertArrayHasKey('last_updated', $responseData);
+		unset($responseData['last_updated']);
+		unset($data['last_updated']);
+		$this->assertEquals($data, $responseData);
+
+		self::logout();
+
+		$response = $this->controller->getShare($id);
+		$responseData = $response->getData();
+		$this->assertEquals(Http::STATUS_NOT_FOUND, $response->getStatus(), var_export($responseData, true));
+		$this->assertEquals('Share ' . $id . ' not found.', $responseData);
+	}
+
+	public function testGetShareFilteredArguments(): void {
+		$this->registry->registerSourceType(new TestShareSourceType(['source' => 'Source']));
+		$this->registry->registerRecipientType(new TestShareRecipientType(['recipient' => 'Recipient'], ['recipient'], []));
+		$this->registry->registerFeature(new TestShareFeatureFilter([['source_type' => TestShareSourceType::class, 'recipient_type' => TestShareRecipientType::class]]));
+
+		$data = [
+			'owner' => [
+				'user_id' => $this->owner1->getUID(),
+				'display_name' => $this->owner1->getDisplayName(),
+			],
+			'sources' => [['type' => TestShareSourceType::class, 'value' => 'source', 'display_name' => 'Source']],
+			'recipients' => [['type' => TestShareRecipientType::class, 'value' => 'recipient', 'display_name' => 'Recipient']],
+			'properties' => [],
+		];
+		$response = $this->controller->createShare($data);
+		/** @var SharingShare $responseData */
+		$responseData = $response->getData();
+		$this->assertEquals(Http::STATUS_CREATED, $response->getStatus(), var_export($responseData, true));
+		$this->assertArrayHasKey('id', $responseData);
+		$id = $responseData['id'];
+		unset($responseData['id']);
+		$this->assertArrayHasKey('last_updated', $responseData);
+		unset($responseData['last_updated']);
+		$this->assertEquals($data, $responseData);
+
+		self::logout();
+
+		$response = $this->controller->getShare($id, [TestShareFeatureFilter::class => 'filtered']);
+		$responseData = $response->getData();
+		$this->assertEquals(Http::STATUS_NOT_FOUND, $response->getStatus(), var_export($responseData, true));
+		$this->assertEquals('Share ' . $id . ' not found.', $responseData);
+
+		$response = $this->controller->getShare($id);
+		/** @var SharingShare $responseData */
+		$responseData = $response->getData();
+		$this->assertEquals(Http::STATUS_OK, $response->getStatus(), var_export($responseData, true));
+		$this->assertArrayHasKey('id', $responseData);
+		unset($responseData['id']);
+		$this->assertArrayHasKey('last_updated', $responseData);
+		unset($responseData['last_updated']);
+		$this->assertEquals($data, $responseData);
+	}
+
+	public function testGetShares(): void {
+		$this->registry->registerSourceType(new TestShareSourceType(['source1' => 'Source 1']));
+		$this->registry->registerSourceType(new TestShareSourceType2(['source2' => 'Source 2']));
+		$this->registry->registerRecipientType(new TestShareRecipientType(['recipient1' => 'Recipient 1'], [], []));
+		$this->registry->registerRecipientType(new TestShareRecipientType2(['recipient2' => 'Recipient 2'], [], []));
+		$this->registry->registerFeature(new TestShareFeature([['source_type' => TestShareSourceType::class, 'recipient_type' => TestShareRecipientType::class]], ['key1']));
+		$this->registry->registerFeature(new TestShareFeature2([['source_type' => TestShareSourceType2::class, 'recipient_type' => TestShareRecipientType2::class]], ['key2']));
+
+		$data1 = [
+			'owner' => [
+				'user_id' => $this->owner1->getUID(),
+				'display_name' => $this->owner1->getDisplayName(),
+			],
+			'sources' => [
+				[
+					'type' => TestShareSourceType::class,
+					'value' => 'source1',
+					'display_name' => 'Source 1',
+				],
+				[
+					'type' => TestShareSourceType2::class,
+					'value' => 'source2',
+					'display_name' => 'Source 2',
+				],
+			],
+			'recipients' => [
+				[
+					'type' => TestShareRecipientType::class,
+					'value' => 'recipient1',
+					'display_name' => 'Recipient 1',
+				],
+				[
+					'type' => TestShareRecipientType2::class,
+					'value' => 'recipient2',
+					'display_name' => 'Recipient 2',
+				],
+			],
+			'properties' => [
+				TestShareFeature::class => [
+					'key1' => ['value1'],
+				],
+				TestShareFeature2::class => [
+					'key2' => ['value2'],
+				],
+			],
+		];
+		$response = $this->controller->createShare($data1);
+		/** @var SharingShare $responseData */
+		$responseData = $response->getData();
+		$this->assertEquals(Http::STATUS_CREATED, $response->getStatus(), var_export($responseData, true));
+		$this->assertArrayHasKey('id', $responseData);
+		unset($responseData['id']);
+		$this->assertArrayHasKey('last_updated', $responseData);
+		unset($responseData['last_updated']);
+		$this->assertEquals($data1, $responseData);
+
+		$data2 = [
+			'owner' => [
+				'user_id' => $this->owner1->getUID(),
+				'display_name' => $this->owner1->getDisplayName(),
+			],
+			'sources' => [
+				[
+					'type' => TestShareSourceType::class,
+					'value' => 'source1',
+					'display_name' => 'Source 1',
+				],
+				[
+					'type' => TestShareSourceType2::class,
+					'value' => 'source2',
+					'display_name' => 'Source 2',
+				],
+			],
+			'recipients' => [
+				[
+					'type' => TestShareRecipientType::class,
+					'value' => 'recipient1',
+					'display_name' => 'Recipient 1',
+				],
+				[
+					'type' => TestShareRecipientType2::class,
+					'value' => 'recipient2',
+					'display_name' => 'Recipient 2',
+				],
+			],
+			'properties' => [
+				TestShareFeature::class => [
+					'key1' => ['value1'],
+				],
+				TestShareFeature2::class => [
+					'key2' => ['value2'],
+				],
+			],
+		];
+		$response = $this->controller->createShare($data2);
+		/** @var SharingShare $responseData */
+		$responseData = $response->getData();
+		$this->assertEquals(Http::STATUS_CREATED, $response->getStatus(), var_export($responseData, true));
+		$this->assertArrayHasKey('id', $responseData);
+		unset($responseData['id']);
+		$this->assertArrayHasKey('last_updated', $responseData);
+		unset($responseData['last_updated']);
+		$this->assertEquals($data2, $responseData);
+
+		$response = $this->controller->getShares();
+		/** @var list<SharingShare> $responseData */
+		$responseData = $response->getData();
+		$this->assertEquals(Http::STATUS_OK, $response->getStatus(), var_export($responseData, true));
+		$this->assertCount(2, $responseData);
+		$this->assertArrayHasKey('id', $responseData[0]);
+		$this->assertArrayHasKey('last_updated', $responseData[0]);
+		$this->assertArrayHasKey('id', $responseData[1]);
+		$this->assertArrayHasKey('last_updated', $responseData[1]);
+		unset($responseData[0]['id'], $responseData[0]['last_updated'], $responseData[1]['id'], $responseData[1]['last_updated']);
+		$this->assertEquals($data1, $responseData[0]);
+		$this->assertEquals($data2, $responseData[1]);
+
+		$response = $this->controller->getShares(TestShareSourceType::class);
+		/** @var list<SharingShare> $responseData */
+		$responseData = $response->getData();
+		$this->assertEquals(Http::STATUS_OK, $response->getStatus(), var_export($responseData, true));
+		$this->assertCount(2, $responseData);
+		$this->assertArrayHasKey('id', $responseData[0]);
+		$this->assertArrayHasKey('last_updated', $responseData[0]);
+		$this->assertArrayHasKey('id', $responseData[1]);
+		$this->assertArrayHasKey('last_updated', $responseData[1]);
+		unset($responseData[0]['id'], $responseData[0]['last_updated'], $responseData[1]['id'], $responseData[1]['last_updated']);
+		$this->assertEquals($data1, $responseData[0]);
+		$this->assertEquals($data2, $responseData[1]);
+
+		/** @psalm-suppress ArgumentTypeCoercion */
+		$response = $this->controller->getShares('invalid');
+		/** @var list<SharingShare> $responseData */
+		$responseData = $response->getData();
+		$this->assertEquals(Http::STATUS_OK, $response->getStatus(), var_export($responseData, true));
+		$this->assertCount(0, $responseData);
+
+		$response = $this->controller->getShares(limit: 1);
+		/** @var list<SharingShare> $responseData */
+		$responseData = $response->getData();
+		$this->assertEquals(Http::STATUS_OK, $response->getStatus(), var_export($responseData, true));
+		$this->assertCount(1, $responseData);
+		$this->assertArrayHasKey('id', $responseData[0]);
+		$this->assertArrayHasKey('last_updated', $responseData[0]);
+		$lastShareId = $responseData[0]['id'];
+		unset($responseData[0]['id'], $responseData[0]['last_updated']);
+		$this->assertEquals($data1, $responseData[0]);
+
+		$response = $this->controller->getShares(lastShareId: $lastShareId);
+		/** @var list<SharingShare> $responseData */
+		$responseData = $response->getData();
+		$this->assertEquals(Http::STATUS_OK, $response->getStatus(), var_export($responseData, true));
+		$this->assertCount(1, $responseData);
+		$this->assertArrayHasKey('id', $responseData[0]);
+		$this->assertArrayHasKey('last_updated', $responseData[0]);
+		unset($responseData[0]['id'], $responseData[0]['last_updated']);
+		$this->assertEquals($data2, $responseData[0]);
+	}
+}

apps/sharing/tests/RegistryTest.php

@@ -0,0 +1,72 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+
+use OCA\Sharing\Registry;
+use OCA\Sharing\Tests\TestShareFeature;
+use OCA\Sharing\Tests\TestShareRecipientType;
+use OCA\Sharing\Tests\TestShareSourceType;
+use OCP\Server;
+use Test\TestCase;
+
+class RegistryTest extends TestCase {
+	private Registry $registry;
+
+	public function setUp(): void {
+		parent::setUp();
+
+		$this->registry = Server::get(Registry::class);
+	}
+
+	protected function tearDown(): void {
+		$this->registry->clear();
+
+		parent::tearDown();
+	}
+
+	public function testRegisterSourceType(): void {
+		$sourceType = new TestShareSourceType([]);
+		$this->registry->registerSourceType($sourceType);
+
+		$this->assertEquals([TestShareSourceType::class => $sourceType], $this->registry->getSourceTypes());
+
+		$this->expectException(RuntimeException::class);
+		$this->registry->registerSourceType($sourceType);
+	}
+
+	public function testRegisterRecipientType(): void {
+		$recipientType = new TestShareRecipientType([], [], []);
+		$this->registry->registerRecipientType($recipientType);
+
+		$this->assertEquals([TestShareRecipientType::class => $recipientType], $this->registry->getRecipientTypes());
+
+		$this->expectException(RuntimeException::class);
+		$this->registry->registerRecipientType($recipientType);
+	}
+
+	public function testRegisterFeature(): void {
+		$feature = new TestShareFeature([['source_type' => TestShareSourceType::class, 'recipient_type' => TestShareRecipientType::class]], []);
+		$this->registry->registerFeature($feature);
+
+		$this->assertEquals([TestShareFeature::class => $feature], $this->registry->getFeatures());
+
+		$this->expectException(RuntimeException::class);
+		$this->registry->registerFeature($feature);
+	}
+
+	public function testClear(): void {
+		$this->registry->registerSourceType(new TestShareSourceType([]));
+		$this->registry->registerRecipientType(new TestShareRecipientType([], [], []));
+		$this->registry->registerFeature(new TestShareFeature([['source_type' => TestShareSourceType::class, 'recipient_type' => TestShareRecipientType::class]], []));
+
+		$this->registry->clear();
+
+		$this->assertEquals([], $this->registry->getFeatures());
+	}
+}

apps/sharing/tests/TestShareFeature.php

@@ -0,0 +1,37 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+namespace OCA\Sharing\Tests;
+
+use OCA\Sharing\Model\IShareFeature;
+use OCA\Sharing\ResponseDefinitions;
+
+/**
+ * @psalm-import-type SharingCompatible from ResponseDefinitions
+ */
+class TestShareFeature implements IShareFeature {
+	public function __construct(
+		/** @var non-empty-list<SharingCompatible> $compatibles */
+		private readonly array $compatibles,
+		/** @var list<string> $validProperties */
+		private readonly array $validProperties,
+	) {
+	}
+
+	/**
+	 * @return non-empty-list<SharingCompatible>
+	 */
+	public function getCompatibles(): array {
+		return $this->compatibles;
+	}
+
+	public function validateProperties(array $properties): bool {
+		return array_intersect(array_keys($properties), $this->validProperties) !== [];
+	}
+}

apps/sharing/tests/TestShareFeature2.php

@@ -0,0 +1,13 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+namespace OCA\Sharing\Tests;
+
+class TestShareFeature2 extends TestShareFeature {
+}

apps/sharing/tests/TestShareFeatureFilter.php

@@ -0,0 +1,41 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+namespace OCA\Sharing\Tests;
+
+use OCA\Sharing\Model\IShareFeatureFilter;
+use OCA\Sharing\ResponseDefinitions;
+use OCP\IUser;
+
+/**
+ * @psalm-import-type SharingCompatible from ResponseDefinitions
+ */
+class TestShareFeatureFilter implements IShareFeatureFilter {
+
+	public function __construct(
+		/** @var non-empty-list<SharingCompatible> $compatibles */
+		private readonly array $compatibles,
+	) {
+	}
+
+	/**
+	 * @return non-empty-list<SharingCompatible>
+	 */
+	public function getCompatibles(): array {
+		return $this->compatibles;
+	}
+
+	public function validateProperties(array $properties): bool {
+		return true;
+	}
+
+	public function isFiltered(?IUser $currentUser, mixed $arguments, array $properties): bool {
+		return $arguments === 'filtered' || (($properties['filtered'] ?? ['false'])[0] === 'true');
+	}
+}

apps/sharing/tests/TestShareFeatureModifyProperties.php

@@ -0,0 +1,45 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+namespace OCA\Sharing\Tests;
+
+use OCA\Sharing\Model\IShareFeatureModifyProperties;
+use OCA\Sharing\ResponseDefinitions;
+
+/**
+ * @psalm-import-type SharingCompatible from ResponseDefinitions
+ */
+class TestShareFeatureModifyProperties implements IShareFeatureModifyProperties {
+
+	public function __construct(
+		/** @var non-empty-list<SharingCompatible> $compatibles */
+		private readonly array $compatibles,
+	) {
+	}
+
+	/**
+	 * @return non-empty-list<SharingCompatible>
+	 */
+	public function getCompatibles(): array {
+		return $this->compatibles;
+	}
+
+	public function validateProperties(array $properties): bool {
+		return (array_keys($properties) === ['before'] && count($properties['before']) === 1 && $properties['before'][0] === 'valid')
+			|| (array_keys($properties) === ['after'] && count($properties['after']) === 1 && $properties['after'][0] === 'valid');
+	}
+
+	/**
+	 * @param array<string, list<string>> $properties
+	 * @return array<string, list<string>>
+	 */
+	public function modifyProperties(array $properties): array {
+		return ['after' => $properties['before']];
+	}
+}

apps/sharing/tests/TestShareRecipientType.php

@@ -0,0 +1,52 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+namespace OCA\Sharing\Tests;
+
+use OCA\Sharing\Model\IShareRecipientType;
+use OCA\Sharing\Model\IShareRecipientTypeSearch;
+use OCA\Sharing\Model\ShareRecipientSearchResult;
+use OCP\IUser;
+
+class TestShareRecipientType implements IShareRecipientType, IShareRecipientTypeSearch {
+	public function __construct(
+		/** @var array<string, non-empty-string> $validRecipients */
+		private readonly array $validRecipients,
+		/** @var list<non-empty-string> $recipients */
+		private readonly array $recipients,
+		/** @var list<ShareRecipientSearchResult> $searchRecipients */
+		private readonly array $searchRecipients,
+	) {
+	}
+
+	public function getDisplayName(): string {
+		/** @var non-empty-list<non-empty-string> $parts */
+		$parts = explode('\\', static::class);
+		return end($parts);
+	}
+
+	public function validateRecipient(string $recipient): bool {
+		return array_key_exists($recipient, $this->validRecipients);
+	}
+
+	/**
+	 * @return list<string>
+	 */
+	public function getRecipientValues(?IUser $currentUser, mixed $arguments): array {
+		return $this->recipients;
+	}
+
+	public function getRecipientDisplayName(string $recipient): ?string {
+		return $this->validRecipients[$recipient];
+	}
+
+	public function searchRecipients(string $query, int $limit, int $offset): array {
+		return array_slice(array_map(static fn (ShareRecipientSearchResult $result): ShareRecipientSearchResult => clone $result, $this->searchRecipients), $offset, $limit);
+	}
+}

apps/sharing/tests/TestShareRecipientType2.php

@@ -0,0 +1,13 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+namespace OCA\Sharing\Tests;
+
+class TestShareRecipientType2 extends TestShareRecipientType {
+}

apps/sharing/tests/TestShareRecipientTypeArguments.php

@@ -0,0 +1,37 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+namespace OCA\Sharing\Tests;
+
+use OCA\Sharing\Model\IShareRecipientType;
+use OCP\IUser;
+
+class TestShareRecipientTypeArguments implements IShareRecipientType {
+	public function getDisplayName(): string {
+		/** @var non-empty-list<non-empty-string> $parts */
+		$parts = explode('\\', static::class);
+		return end($parts);
+	}
+
+	public function validateRecipient(string $recipient): bool {
+		return true;
+	}
+
+	public function getRecipientValues(?IUser $currentUser, mixed $arguments): array {
+		if (is_string($arguments)) {
+			return [$arguments];
+		}
+
+		return [];
+	}
+
+	public function getRecipientDisplayName(string $recipient): ?string {
+		return null;
+	}
+}

apps/sharing/tests/TestShareSourceType.php

@@ -0,0 +1,35 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+namespace OCA\Sharing\Tests;
+
+use OCA\Sharing\Model\IShareSourceType;
+use OCP\IUser;
+
+class TestShareSourceType implements IShareSourceType {
+	public function __construct(
+		/** @var array<string, non-empty-string> $validSources */
+		private readonly array $validSources,
+	) {
+	}
+
+	public function getDisplayName(): string {
+		/** @var non-empty-list<non-empty-string> $parts */
+		$parts = explode('\\', static::class);
+		return end($parts);
+	}
+
+	public function validateSource(IUser $owner, string $source): bool {
+		return array_key_exists($source, $this->validSources);
+	}
+
+	public function getSourceDisplayName(string $source): ?string {
+		return $this->validSources[$source];
+	}
+}

apps/sharing/tests/TestShareSourceType2.php

@@ -0,0 +1,13 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+namespace OCA\Sharing\Tests;
+
+class TestShareSourceType2 extends TestShareSourceType {
+}

build/rector-strict.php

@@ -24,6 +24,11 @@ return (require __DIR__ . '/rector-shared.php')
 		$nextcloudDir . '/build/psalm/ITypedQueryBuilderTest.php',
 		$nextcloudDir . '/lib/private/DB/QueryBuilder/TypedQueryBuilder.php',
 		$nextcloudDir . '/lib/public/DB/QueryBuilder/ITypedQueryBuilder.php',
+		$nextcloudDir . '/apps/files/lib/Sharing',
+		$nextcloudDir . '/apps/files/tests/Sharing',
+		$nextcloudDir . '/apps/sharing',
+		$nextcloudDir . '/core/Sharing',
+		$nextcloudDir . '/tests/Core/Sharing',
 	])
 	->withPreparedSets(
 		deadCode: true,

core/AppInfo/Application.php

@@ -22,8 +22,14 @@ use OC\Core\Listener\AddMissingPrimaryKeyListener;
 use OC\Core\Listener\BeforeTemplateRenderedListener;
 use OC\Core\Listener\PasswordUpdatedListener;
 use OC\Core\Notification\CoreNotifier;
+use OC\Core\Sharing\Feature\ExpirationShareFeature;
+use OC\Core\Sharing\Feature\LabelShareFeature;
+use OC\Core\Sharing\Feature\NoteShareFeature;
+use OC\Core\Sharing\RecipientType\GroupShareRecipientType;
+use OC\Core\Sharing\RecipientType\UserShareRecipientType;
 use OC\OCM\OCMDiscoveryHandler;
 use OC\TagManager;
+use OCA\Sharing\Registry;
 use OCP\AppFramework\App;
 use OCP\AppFramework\Bootstrap\IBootContext;
 use OCP\AppFramework\Bootstrap\IBootstrap;
@@ -32,6 +38,7 @@ use OCP\AppFramework\Http\Events\BeforeLoginTemplateRenderedEvent;
 use OCP\AppFramework\Http\Events\BeforeTemplateRenderedEvent;
 use OCP\DB\Events\AddMissingIndicesEvent;
 use OCP\DB\Events\AddMissingPrimaryKeyEvent;
+use OCP\Server;
 use OCP\User\Events\BeforeUserDeletedEvent;
 use OCP\User\Events\PasswordUpdatedEvent;
 use OCP\User\Events\UserDeletedEvent;
@@ -88,6 +95,14 @@ class Application extends App implements IBootstrap {
 
 		$context->registerWellKnownHandler(OCMDiscoveryHandler::class);
 		$context->registerCapability(Capabilities::class);
+
+		$registry = Server::get(Registry::class);
+		$registry->registerRecipientType(new GroupShareRecipientType());
+		$registry->registerRecipientType(new UserShareRecipientType());
+		$registry->registerFeature(new ExpirationShareFeature());
+		$registry->registerFeature(new LabelShareFeature());
+		$registry->registerFeature(new NoteShareFeature());
+
 	}
 
 	public function boot(IBootContext $context): void {

core/Sharing/Feature/ExpirationShareFeature.php

@@ -0,0 +1,55 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OC\Core\Sharing\Feature;
+
+use DateTimeImmutable;
+use Exception;
+use OC\Core\Sharing\RecipientType\GroupShareRecipientType;
+use OC\Core\Sharing\RecipientType\UserShareRecipientType;
+use OCA\Files\Sharing\SourceType\NodeShareSourceType;
+use OCA\Sharing\Model\IShareFeature;
+use OCA\Sharing\Model\IShareFeatureFilter;
+use OCP\IUser;
+
+class ExpirationShareFeature implements IShareFeature, IShareFeatureFilter {
+	public function getCompatibles(): array {
+		$compatibles = [];
+		foreach ([NodeShareSourceType::class] as $sourceType) {
+			foreach ([UserShareRecipientType::class, GroupShareRecipientType::class] as $recipientType) {
+				$compatibles[] = [
+					'source_type' => $sourceType,
+					'recipient_type' => $recipientType,
+				];
+			}
+		}
+
+		return $compatibles;
+	}
+
+	public function validateProperties(array $properties): bool {
+		if (array_keys($properties) !== ['date'] || count($properties['date']) !== 1 || $properties['date'][0] === '') {
+			return false;
+		}
+
+		try {
+			new DateTimeImmutable($properties['date'][0]);
+			return true;
+		} catch (Exception) {
+			return false;
+		}
+	}
+
+	/**
+	 * @throws Exception
+	 */
+	public function isFiltered(?IUser $currentUser, mixed $arguments, array $properties): bool {
+		return (new DateTimeImmutable($properties['date'][0]))->diff(new DateTimeImmutable())->invert === 0;
+	}
+}

core/Sharing/Feature/LabelShareFeature.php

@@ -0,0 +1,35 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OC\Core\Sharing\Feature;
+
+use OC\Core\Sharing\RecipientType\GroupShareRecipientType;
+use OC\Core\Sharing\RecipientType\UserShareRecipientType;
+use OCA\Files\Sharing\SourceType\NodeShareSourceType;
+use OCA\Sharing\Model\IShareFeature;
+
+class LabelShareFeature implements IShareFeature {
+	public function getCompatibles(): array {
+		$compatibles = [];
+		foreach ([NodeShareSourceType::class] as $sourceType) {
+			foreach ([UserShareRecipientType::class, GroupShareRecipientType::class] as $recipientType) {
+				$compatibles[] = [
+					'source_type' => $sourceType,
+					'recipient_type' => $recipientType,
+				];
+			}
+		}
+
+		return $compatibles;
+	}
+
+	public function validateProperties(array $properties): bool {
+		return array_keys($properties) === ['text'] && count($properties['text']) === 1 && $properties['text'][0] !== '';
+	}
+}

core/Sharing/Feature/NoteShareFeature.php

@@ -0,0 +1,35 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OC\Core\Sharing\Feature;
+
+use OC\Core\Sharing\RecipientType\GroupShareRecipientType;
+use OC\Core\Sharing\RecipientType\UserShareRecipientType;
+use OCA\Files\Sharing\SourceType\NodeShareSourceType;
+use OCA\Sharing\Model\IShareFeature;
+
+class NoteShareFeature implements IShareFeature {
+	public function getCompatibles(): array {
+		$compatibles = [];
+		foreach ([NodeShareSourceType::class] as $sourceType) {
+			foreach ([UserShareRecipientType::class, GroupShareRecipientType::class] as $recipientType) {
+				$compatibles[] = [
+					'source_type' => $sourceType,
+					'recipient_type' => $recipientType,
+				];
+			}
+		}
+
+		return $compatibles;
+	}
+
+	public function validateProperties(array $properties): bool {
+		return array_keys($properties) === ['text'] && count($properties['text']) === 1 && $properties['text'][0] !== '';
+	}
+}

core/Sharing/Feature/PasswordShareFeature.php

@@ -0,0 +1,84 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OC\Core\Sharing\Feature;
+
+use Exception;
+use OC\Core\Sharing\RecipientType\TokenShareRecipientType;
+use OCA\Files\Sharing\SourceType\NodeShareSourceType;
+use OCA\Sharing\Model\IShareFeature;
+use OCA\Sharing\Model\IShareFeatureFilter;
+use OCA\Sharing\Model\IShareFeatureModifyProperties;
+use OCP\EventDispatcher\IEventDispatcher;
+use OCP\IUser;
+use OCP\Security\Events\ValidatePasswordPolicyEvent;
+use OCP\Security\IHasher;
+use OCP\Security\PasswordContext;
+use OCP\Server;
+
+class PasswordShareFeature implements IShareFeature, IShareFeatureModifyProperties, IShareFeatureFilter {
+	public function getCompatibles(): array {
+		$compatibles = [];
+		foreach ([NodeShareSourceType::class] as $sourceType) {
+			foreach ([TokenShareRecipientType::class] as $recipientType) {
+				$compatibles[] = [
+					'source_type' => $sourceType,
+					'recipient_type' => $recipientType,
+				];
+			}
+		}
+
+		return $compatibles;
+	}
+
+	public function validateProperties(array $properties): bool {
+		if (array_keys($properties) === ['hash']) {
+			if (count($properties['hash']) !== 1) {
+				return false;
+			}
+
+			return Server::get(IHasher::class)->validate($properties['hash'][0]);
+		}
+
+		if (array_keys($properties) === ['password']) {
+			if (count($properties['password']) !== 1) {
+				return false;
+			}
+
+			try {
+				Server::get(IEventDispatcher::class)->dispatchTyped(new ValidatePasswordPolicyEvent($properties['password'][0], PasswordContext::SHARING));
+				return true;
+			} catch (Exception) {
+				return false;
+			}
+		}
+
+		return false;
+	}
+
+	public function modifyProperties(array $properties): array {
+		if (array_keys($properties) === ['hash']) {
+			return $properties;
+		}
+
+		return ['hash' => [Server::get(IHasher::class)->hash($properties['password'][0])]];
+	}
+
+	/**
+	 * @throws Exception
+	 */
+	public function isFiltered(?IUser $currentUser, mixed $arguments, array $properties): bool {
+		if (!is_string($arguments)) {
+			return true;
+		}
+
+		// TODO: Check if the hash has to be updated and save it.
+		return !Server::get(IHasher::class)->verify($arguments, $properties['hash'][0]);
+	}
+}

core/Sharing/RecipientType/GroupShareRecipientType.php

@@ -0,0 +1,100 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+namespace OC\Core\Sharing\RecipientType;
+
+use OCA\Sharing\Model\IShareRecipientType;
+use OCA\Sharing\Model\IShareRecipientTypeSearch;
+use OCA\Sharing\Model\ShareRecipientSearchResult;
+use OCP\Collaboration\Collaborators\ISearch;
+use OCP\IGroupManager;
+use OCP\IL10N;
+use OCP\IUser;
+use OCP\Server;
+use OCP\Share\IShare;
+use RuntimeException;
+
+class GroupShareRecipientType implements IShareRecipientType, IShareRecipientTypeSearch {
+	public function getDisplayName(): string {
+		return Server::get(IL10N::class)->t('Group');
+	}
+
+	public function validateRecipient(string $recipient): bool {
+		return Server::get(IGroupManager::class)->groupExists($recipient);
+	}
+
+	public function getRecipientValues(?IUser $currentUser, mixed $arguments): array {
+		if (!$currentUser instanceof IUser) {
+			return [];
+		}
+
+		return Server::get(IGroupManager::class)->getUserGroupIds($currentUser);
+	}
+
+	public function getRecipientDisplayName(string $recipient): ?string {
+		$displayName = Server::get(IGroupManager::class)->getDisplayName($recipient);
+		if ($displayName === '') {
+			return null;
+		}
+
+		return $displayName;
+	}
+
+	/**
+	 * @return list<ShareRecipientSearchResult>
+	 */
+	public function searchRecipients(string $query, int $limit, int $offset): array {
+		// TODO: Maybe enable lookup?
+		/** @var array{array{groups: list<array>}, bool} $results */
+		$results = Server::get(ISearch::class)->search($query, [IShare::TYPE_GROUP], false, $limit, $offset);
+		$results = $results[0]['groups'];
+
+		return array_map(static function (array $result): ShareRecipientSearchResult {
+			if (!isset($result['value'])) {
+				throw new RuntimeException('The value is missing.');
+			}
+
+			if (!is_array($result['value'])) {
+				throw new RuntimeException('The value is not an array.');
+			}
+
+			if (!isset($result['value']['shareWith'])) {
+				throw new RuntimeException('The shareWith is missing.');
+			}
+
+			if (!is_string($result['value']['shareWith'])) {
+				throw new RuntimeException('The shareWith is not a string.');
+			}
+
+			if ($result['value']['shareWith'] === '') {
+				throw new RuntimeException('The shareWith is empty.');
+			}
+
+			if (!isset($result['label'])) {
+				throw new RuntimeException('The label is missing.');
+			}
+
+			if (!is_string($result['label'])) {
+				throw new RuntimeException('The label is not a string.');
+			}
+
+			if ($result['label'] === '') {
+				throw new RuntimeException('The label is empty.');
+			}
+
+			return new ShareRecipientSearchResult(
+				$result['value']['shareWith'],
+				$result['label'],
+				null,
+				null,
+				null,
+			);
+		}, $results);
+	}
+}

core/Sharing/RecipientType/TokenShareRecipientType.php

@@ -0,0 +1,38 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+namespace OC\Core\Sharing\RecipientType;
+
+use OC\Share\Constants;
+use OCA\Sharing\Model\IShareRecipientType;
+use OCP\IL10N;
+use OCP\IUser;
+use OCP\Server;
+
+class TokenShareRecipientType implements IShareRecipientType {
+	public function getDisplayName(): string {
+		return Server::get(IL10N::class)->t('Public link');
+	}
+
+	public function validateRecipient(string $recipient): bool {
+		return preg_match('/^[a-z0-9-]{' . Constants::MIN_TOKEN_LENGTH . ',' . Constants::MAX_TOKEN_LENGTH . '}$/i', $recipient) === 1;
+	}
+
+	public function getRecipientValues(?IUser $currentUser, mixed $arguments): array {
+		if (is_string($arguments)) {
+			return [$arguments];
+		}
+
+		return [];
+	}
+
+	public function getRecipientDisplayName(string $recipient): ?string {
+		return null;
+	}
+}

core/Sharing/RecipientType/UserShareRecipientType.php

@@ -0,0 +1,121 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+namespace OC\Core\Sharing\RecipientType;
+
+use OCA\Sharing\Model\IShareRecipientType;
+use OCA\Sharing\Model\IShareRecipientTypeSearch;
+use OCA\Sharing\Model\ShareRecipientSearchResult;
+use OCP\Collaboration\Collaborators\ISearch;
+use OCP\IL10N;
+use OCP\IURLGenerator;
+use OCP\IUser;
+use OCP\IUserManager;
+use OCP\Server;
+use OCP\Share\IShare;
+use RuntimeException;
+
+class UserShareRecipientType implements IShareRecipientType, IShareRecipientTypeSearch {
+	public function getDisplayName(): string {
+		return Server::get(IL10N::class)->t('User');
+	}
+
+	public function validateRecipient(string $recipient): bool {
+		return Server::get(IUserManager::class)->userExists($recipient);
+	}
+
+	public function getRecipientValues(?IUser $currentUser, mixed $arguments): array {
+		if (!$currentUser instanceof IUser) {
+			return [];
+		}
+
+		return [$currentUser->getUID()];
+	}
+
+	public function getRecipientDisplayName(string $recipient): ?string {
+		return Server::get(IUserManager::class)->getDisplayName($recipient);
+	}
+
+	/**
+	 * @return list<ShareRecipientSearchResult>
+	 */
+	public function searchRecipients(string $query, int $limit, int $offset): array {
+		// TODO: Maybe enable lookup?
+		/** @var array{array{users: list<array>}, bool} $results */
+		$results = Server::get(ISearch::class)->search($query, [IShare::TYPE_USER], false, $limit, $offset);
+		$results = $results[0]['users'];
+
+		$urlGenerator = Server::get(IURLGenerator::class);
+		return array_map(static function (array $result) use ($urlGenerator): ShareRecipientSearchResult {
+			if (!isset($result['value'])) {
+				throw new RuntimeException('The value is missing.');
+			}
+
+			if (!is_array($result['value'])) {
+				throw new RuntimeException('The value is not an array.');
+			}
+
+			if (!isset($result['value']['shareWith'])) {
+				throw new RuntimeException('The shareWith is missing.');
+			}
+
+			if (!is_string($result['value']['shareWith'])) {
+				throw new RuntimeException('The shareWith is not a string.');
+			}
+
+			if ($result['value']['shareWith'] === '') {
+				throw new RuntimeException('The shareWith is empty.');
+			}
+
+			if (!isset($result['label'])) {
+				throw new RuntimeException('The label is missing.');
+			}
+
+			if (!is_string($result['label'])) {
+				throw new RuntimeException('The label is not a string.');
+			}
+
+			if ($result['label'] === '') {
+				throw new RuntimeException('The label is empty.');
+			}
+
+			if (!isset($result['shareWithDisplayNameUnique'])) {
+				throw new RuntimeException('The shareWithDisplayNameUnique is missing.');
+			}
+
+			if (!is_string($result['shareWithDisplayNameUnique'])) {
+				throw new RuntimeException('The shareWithDisplayNameUnique is not a string.');
+			}
+
+			if ($result['shareWithDisplayNameUnique'] === '') {
+				throw new RuntimeException('The shareWithDisplayNameUnique is empty.');
+			}
+
+			$uid = $result['value']['shareWith'];
+
+			$iconUrlLight = $urlGenerator->linkToRouteAbsolute('core.avatar.getAvatar', ['userId' => $uid, 'size' => 64]);
+			if ($iconUrlLight === '') {
+				throw new RuntimeException('The iconUrlLight is empty.');
+			}
+
+			$iconUrlDark = $urlGenerator->linkToRouteAbsolute('core.avatar.getAvatarDark', ['userId' => $uid, 'size' => 64]);
+			if ($iconUrlDark === '') {
+				throw new RuntimeException('The iconUrlDark is empty.');
+			}
+
+			return new ShareRecipientSearchResult(
+				$uid,
+				$result['label'],
+				$result['shareWithDisplayNameUnique'],
+				$iconUrlLight,
+				$iconUrlDark,
+			);
+		}, $results);
+	}
+}

core/shipped.json

@@ -37,6 +37,7 @@
     "serverinfo",
     "settings",
     "sharebymail",
+    "sharing",
     "support",
     "survey_client",
     "suspicious_login",
@@ -109,6 +110,7 @@
     "profile",
     "provisioning_api",
     "settings",
+    "sharing",
     "theming",
     "twofactor_backupcodes",
     "viewer",

lib/composer/composer/InstalledVersions.php

@@ -277,7 +277,7 @@ class InstalledVersions
         if (null === self::$installed) {
             // only require the installed.php file if this file is loaded from its dumped location,
             // and not from its source location in the composer/composer package, see https://github.com/composer/composer/issues/9937
-            if (substr(__DIR__, -8, 1) !== 'C' && is_file(__DIR__ . '/installed.php')) {
+            if (substr(__DIR__, -8, 1) !== 'C') {
                 self::$installed = include __DIR__ . '/installed.php';
             } else {
                 self::$installed = array();
@@ -378,7 +378,7 @@ class InstalledVersions
         if (null === self::$installed) {
             // only require the installed.php file if this file is loaded from its dumped location,
             // and not from its source location in the composer/composer package, see https://github.com/composer/composer/issues/9937
-            if (substr(__DIR__, -8, 1) !== 'C' && is_file(__DIR__ . '/installed.php')) {
+            if (substr(__DIR__, -8, 1) !== 'C') {
                 /** @var array{root: array{name: string, pretty_version: string, version: string, reference: string|null, type: string, install_path: string, aliases: string[], dev: bool}, versions: array<string, array{pretty_version?: string, version?: string, reference?: string|null, type?: string, install_path?: string, aliases?: string[], dev_requirement: bool, replaced?: string[], provided?: string[]}>} $required */
                 $required = require __DIR__ . '/installed.php';
                 self::$installed = $required;

lib/composer/composer/autoload_classmap.php

@@ -1601,6 +1601,13 @@ return array(
     'OC\\Core\\ResponseDefinitions' => $baseDir . '/core/ResponseDefinitions.php',
     'OC\\Core\\Service\\CronService' => $baseDir . '/core/Service/CronService.php',
     'OC\\Core\\Service\\LoginFlowV2Service' => $baseDir . '/core/Service/LoginFlowV2Service.php',
+    'OC\\Core\\Sharing\\Feature\\ExpirationShareFeature' => $baseDir . '/core/Sharing/Feature/ExpirationShareFeature.php',
+    'OC\\Core\\Sharing\\Feature\\LabelShareFeature' => $baseDir . '/core/Sharing/Feature/LabelShareFeature.php',
+    'OC\\Core\\Sharing\\Feature\\NoteShareFeature' => $baseDir . '/core/Sharing/Feature/NoteShareFeature.php',
+    'OC\\Core\\Sharing\\Feature\\PasswordShareFeature' => $baseDir . '/core/Sharing/Feature/PasswordShareFeature.php',
+    'OC\\Core\\Sharing\\RecipientType\\GroupShareRecipientType' => $baseDir . '/core/Sharing/RecipientType/GroupShareRecipientType.php',
+    'OC\\Core\\Sharing\\RecipientType\\TokenShareRecipientType' => $baseDir . '/core/Sharing/RecipientType/TokenShareRecipientType.php',
+    'OC\\Core\\Sharing\\RecipientType\\UserShareRecipientType' => $baseDir . '/core/Sharing/RecipientType/UserShareRecipientType.php',
     'OC\\DB\\Adapter' => $baseDir . '/lib/private/DB/Adapter.php',
     'OC\\DB\\AdapterMySQL' => $baseDir . '/lib/private/DB/AdapterMySQL.php',
     'OC\\DB\\AdapterOCI8' => $baseDir . '/lib/private/DB/AdapterOCI8.php',

lib/composer/composer/autoload_static.php

@@ -1642,6 +1642,13 @@ class ComposerStaticInit749170dad3f5e7f9ca158f5a9f04f6a2
         'OC\\Core\\ResponseDefinitions' => __DIR__ . '/../../..' . '/core/ResponseDefinitions.php',
         'OC\\Core\\Service\\CronService' => __DIR__ . '/../../..' . '/core/Service/CronService.php',
         'OC\\Core\\Service\\LoginFlowV2Service' => __DIR__ . '/../../..' . '/core/Service/LoginFlowV2Service.php',
+        'OC\\Core\\Sharing\\Feature\\ExpirationShareFeature' => __DIR__ . '/../../..' . '/core/Sharing/Feature/ExpirationShareFeature.php',
+        'OC\\Core\\Sharing\\Feature\\LabelShareFeature' => __DIR__ . '/../../..' . '/core/Sharing/Feature/LabelShareFeature.php',
+        'OC\\Core\\Sharing\\Feature\\NoteShareFeature' => __DIR__ . '/../../..' . '/core/Sharing/Feature/NoteShareFeature.php',
+        'OC\\Core\\Sharing\\Feature\\PasswordShareFeature' => __DIR__ . '/../../..' . '/core/Sharing/Feature/PasswordShareFeature.php',
+        'OC\\Core\\Sharing\\RecipientType\\GroupShareRecipientType' => __DIR__ . '/../../..' . '/core/Sharing/RecipientType/GroupShareRecipientType.php',
+        'OC\\Core\\Sharing\\RecipientType\\TokenShareRecipientType' => __DIR__ . '/../../..' . '/core/Sharing/RecipientType/TokenShareRecipientType.php',
+        'OC\\Core\\Sharing\\RecipientType\\UserShareRecipientType' => __DIR__ . '/../../..' . '/core/Sharing/RecipientType/UserShareRecipientType.php',
         'OC\\DB\\Adapter' => __DIR__ . '/../../..' . '/lib/private/DB/Adapter.php',
         'OC\\DB\\AdapterMySQL' => __DIR__ . '/../../..' . '/lib/private/DB/AdapterMySQL.php',
         'OC\\DB\\AdapterOCI8' => __DIR__ . '/../../..' . '/lib/private/DB/AdapterOCI8.php',

lib/composer/composer/installed.php

@@ -3,7 +3,7 @@
         'name' => '__root__',
         'pretty_version' => 'dev-master',
         'version' => 'dev-master',
-        'reference' => '671cec33f134e670bb21c5e3c49c685bd78fc339',
+        'reference' => 'e564c61e163f17a4ad349f0474a184e49eeeef5a',
         'type' => 'library',
         'install_path' => __DIR__ . '/../../../',
         'aliases' => array(),
@@ -13,7 +13,7 @@
         '__root__' => array(
             'pretty_version' => 'dev-master',
             'version' => 'dev-master',
-            'reference' => '671cec33f134e670bb21c5e3c49c685bd78fc339',
+            'reference' => 'e564c61e163f17a4ad349f0474a184e49eeeef5a',
             'type' => 'library',
             'install_path' => __DIR__ . '/../../../',
             'aliases' => array(),

lib/private/Group/Group.php

@@ -41,12 +41,14 @@ class Group implements IGroup {
 	private bool $usersLoaded = false;
 
 	public function __construct(
+		/** @var non-empty-string $gid */
 		private string $gid,
 		/** @var list<GroupInterface> */
 		private array $backends,
 		private IEventDispatcher $dispatcher,
 		private IUserManager $userManager,
 		private ?PublicEmitter $emitter = null,
+		/** @var ?non-empty-string $displayName */
 		protected ?string $displayName = null,
 	) {
 	}
@@ -60,7 +62,7 @@ class Group implements IGroup {
 			foreach ($this->backends as $backend) {
 				if ($backend instanceof IGetDisplayNameBackend) {
 					$displayName = $backend->getDisplayName($this->gid);
-					if (trim($displayName) !== '') {
+					if ($displayName !== '') {
 						$this->displayName = $displayName;
 						return $this->displayName;
 					}

lib/private/L10N/L10N.php

@@ -54,15 +54,6 @@ class L10N implements IL10N {
 		return $this->locale ?? '';
 	}
 
-	/**
-	 * Translating
-	 * @param string $text The text we need a translation for
-	 * @param array|string $parameters default:array() Parameters for sprintf
-	 * @return string Translation or the same text
-	 *
-	 * Returns the translation. If no translation is found, $text will be
-	 * returned.
-	 */
 	public function t(string $text, $parameters = []): string {
 		if (!\is_array($parameters)) {
 			$parameters = [$parameters];

lib/private/L10N/L10NString.php

@@ -19,6 +19,9 @@ class L10NString implements \JsonSerializable {
 	) {
 	}
 
+	/**
+	 * @return non-empty-string
+	 */
 	public function __toString(): string {
 		$translations = $this->l10n->getTranslations();
 		$identityTranslator = $this->l10n->getIdentityTranslator();
@@ -51,7 +54,12 @@ class L10NString implements \JsonSerializable {
 		// $count as %count% as per \Symfony\Contracts\Translation\TranslatorInterface
 		$text = $identityTranslator->trans($identity, $parameters);
 
-		return vsprintf($text, $this->parameters);
+		$text = vsprintf($text, $this->parameters);
+		if ($text === '') {
+			throw new \RuntimeException('The translated text is empty: ' . $this->text);
+		}
+
+		return $text;
 	}
 
 	public function jsonSerialize(): string {

lib/private/Snowflake/SnowflakeGenerator.php

@@ -13,6 +13,7 @@ use OCP\AppFramework\Utility\ITimeFactory;
 use OCP\IConfig;
 use OCP\Snowflake\ISnowflakeGenerator;
 use Override;
+use RuntimeException;
 
 /**
  * Nextcloud Snowflake ID generator
@@ -68,6 +69,9 @@ final readonly class SnowflakeGenerator implements ISnowflakeGenerator {
 	/**
 	 * Mostly copied from Symfony:
 	 * https://github.com/symfony/symfony/blob/v7.3.4/src/Symfony/Component/Uid/BinaryUtil.php#L49
+	 *
+	 * @param non-empty-list<non-negative-int> $bytes
+	 * @return non-empty-string
 	 */
 	private function convertToDecimal(array $bytes): string {
 		$base = 10;
@@ -91,6 +95,10 @@ final readonly class SnowflakeGenerator implements ISnowflakeGenerator {
 			$bytes = $quotient;
 		}
 
+		if ($digits === '') {
+			throw new RuntimeException('Empty digits: ' . var_export($bytes, true));
+		}
+
 		return $digits;
 	}
 

lib/private/User/DisplayNameCache.php

@@ -37,6 +37,9 @@ class DisplayNameCache implements IEventListener {
 		$this->memCache = $cacheFactory->createDistributed('displayNameMappingCache');
 	}
 
+	/**
+	 * @return ?non-empty-string
+	 */
 	public function getDisplayName(string $userId): ?string {
 		if (isset($this->cache[$userId])) {
 			return $this->cache[$userId];

lib/private/User/LazyUser.php

@@ -16,8 +16,10 @@ class LazyUser implements IUser {
 	private ?IUser $user = null;
 
 	public function __construct(
+		/** @var non-empty-string $uid */
 		private string $uid,
 		private IUserManager $userManager,
+		/** @var ?non-empty-string $displayName */
 		private ?string $displayName = null,
 		private ?UserInterface $backend = null,
 	) {

lib/private/User/User.php

@@ -54,6 +54,7 @@ class User implements IUser {
 	private IURLGenerator $urlGenerator;
 	protected ?IAccountManager $accountManager = null;
 
+	/** @var ?non-empty-string $displayName */
 	private ?string $displayName = null;
 	private ?bool $enabled = null;
 	private ?string $home = null;
@@ -63,6 +64,7 @@ class User implements IUser {
 	private ?IAvatarManager $avatarManager = null;
 
 	public function __construct(
+		/** @var non-empty-string $uid */
 		private string $uid,
 		private ?UserInterface $backend,
 		private IEventDispatcher $dispatcher,

lib/public/IGroup.php

@@ -15,7 +15,7 @@ namespace OCP;
  */
 interface IGroup {
 	/**
-	 * @return string
+	 * @return non-empty-string
 	 * @since 8.0.0
 	 */
 	public function getGID(): string;
@@ -23,7 +23,7 @@ interface IGroup {
 	/**
 	 * Returns the group display name
 	 *
-	 * @return string
+	 * @return non-empty-string
 	 * @since 12.0.0
 	 */
 	public function getDisplayName(): string;

lib/public/IL10N.php

@@ -19,9 +19,9 @@ namespace OCP;
 interface IL10N {
 	/**
 	 * Translating
-	 * @param string $text The text we need a translation for
-	 * @param array|string $parameters default:array() Parameters for sprintf
-	 * @return string Translation or the same text
+	 * @param non-empty-string $text The text we need a translation for
+	 * @param array|non-empty-string $parameters default:array() Parameters for sprintf
+	 * @return non-empty-string Translation or the same text
 	 *
 	 * Returns the translation. If no translation is found, $text will be
 	 * returned.

lib/public/IUser.php

@@ -26,7 +26,7 @@ interface IUser {
 	/**
 	 * get the user id
 	 *
-	 * @return string
+	 * @return non-empty-string
 	 * @since 8.0.0
 	 */
 	public function getUID();
@@ -34,7 +34,7 @@ interface IUser {
 	/**
 	 * get the display name for the user, if no specific display name is set it will fallback to the user id
 	 *
-	 * @return string
+	 * @return non-empty-string
 	 * @since 8.0.0
 	 */
 	public function getDisplayName();

lib/public/IUserManager.php

@@ -75,7 +75,7 @@ interface IUserManager {
 	 * Get the display name of a user
 	 *
 	 * @param string $uid
-	 * @return string|null
+	 * @return non-empty-string|null
 	 * @since 25.0.0
 	 */
 	public function getDisplayName(string $uid): ?string;

lib/public/Snowflake/ISnowflakeGenerator.php

@@ -40,6 +40,8 @@ interface ISnowflakeGenerator {
 	 *
 	 * Each call to this method is guaranteed to return a different ID.
 	 *
+	 * @return non-empty-string
+	 *
 	 * @since 33.0
 	 */
 	public function nextId(): string;

psalm-strict.xml

@@ -15,6 +15,9 @@
 	findUnusedVariablesAndParams="true"
 	phpVersion="8.2"
 >
+	<plugins>
+		<pluginClass class="Psalm\PhpUnitPlugin\Plugin"/>
+	</plugins>
 	<projectFiles>
 		<file name="core/BackgroundJobs/ExpirePreviewsJob.php"/>
 		<file name="lib/public/IContainer.php"/>
@@ -32,18 +35,25 @@
 		<file name="lib/public/DB/QueryBuilder/ITypedQueryBuilder.php"/>
 		<file name="lib/private/Share20/ShareHelper.php"/>
 		<file name="lib/public/Share/IShareHelper.php"/>
+		<directory name="apps/files/lib/Sharing"/>
+		<directory name="apps/files/tests/Sharing"/>
+		<directory name="apps/sharing"/>
+		<directory name="core/Sharing"/>
+		<directory name="tests/Core/Sharing"/>
 		<ignoreFiles>
 			<directory name="apps/**/composer"/>
-			<directory name="apps/**/tests"/>
 			<directory name="lib/composer"/>
 			<directory name="lib/l10n"/>
 			<directory name="3rdparty"/>
+			<file name="lib/public/AppFramework/OCSController.php"/>
 		</ignoreFiles>
 	</projectFiles>
 	<extraFiles>
 		<directory name="apps/dav/lib"/>
 		<directory name="apps/settings/lib"/>
 		<directory name="3rdparty"/>
+		<directory name="tests/lib"/>
+		<directory name="vendor-bin/phpunit/vendor/phpunit/phpunit"/>
 	</extraFiles>
 	<stubs>
 		<!-- Psalm does not find methods in here through <extraFiles/> 🤷‍♀️ -->

psalm.xml

@@ -18,6 +18,7 @@
 		<plugin filename="build/psalm/AppFrameworkTainter.php" />
 		<plugin filename="build/psalm/AttributeNamedParameters.php" />
 		<plugin filename="build/psalm/LogicalOperatorChecker.php" />
+		<pluginClass class="Psalm\PhpUnitPlugin\Plugin"/>
 	</plugins>
 	<projectFiles>
 		<directory name="apps/admin_audit"/>
@@ -41,6 +42,7 @@
 		<directory name="apps/provisioning_api"/>
 		<directory name="apps/settings"/>
 		<directory name="apps/sharebymail"/>
+		<directory name="apps/sharing"/>
 		<directory name="apps/systemtags"/>
 		<directory name="apps/testing"/>
 		<directory name="apps/theming"/>

tests/Core/Sharing/Feature/ExpirationShareFeatureTest.php

@@ -0,0 +1,50 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+
+namespace Tests\Core\Sharing\Feature;
+
+use DateInterval;
+use DateTimeImmutable;
+use DateTimeInterface;
+use OC\Core\Sharing\Feature\ExpirationShareFeature;
+use Test\TestCase;
+
+class ExpirationShareFeatureTest extends TestCase {
+	private ExpirationShareFeature $feature;
+
+	public function setUp(): void {
+		parent::setUp();
+
+		$this->feature = new ExpirationShareFeature();
+	}
+
+	public function testValidateProperties(): void {
+		$now = (new DateTimeImmutable())->format(DateTimeInterface::ATOM);
+
+		$this->assertTrue($this->feature->validateProperties(['date' => [$now]]));
+
+		$this->assertFalse($this->feature->validateProperties([]));
+		$this->assertFalse($this->feature->validateProperties(['a' => []]));
+		$this->assertFalse($this->feature->validateProperties(['date' => [$now], 'a' => ['']]));
+		$this->assertFalse($this->feature->validateProperties(['date' => []]));
+		$this->assertFalse($this->feature->validateProperties(['date' => ['']]));
+		$this->assertFalse($this->feature->validateProperties(['date' => [$now, $now]]));
+	}
+
+	public function testIsFiltered(): void {
+		$now = new DateTimeImmutable();
+		$future = $now->add(new DateInterval('PT1M'))->format(DateTimeInterface::ATOM);
+		$past = $now->sub(new DateInterval('PT1M'))->format(DateTimeInterface::ATOM);
+
+		$this->assertFalse($this->feature->isFiltered(null, null, ['date' => [$future]]));
+		$this->assertTrue($this->feature->isFiltered(null, null, ['date' => [$now->format(DateTimeInterface::ATOM)]]));
+		$this->assertTrue($this->feature->isFiltered(null, null, ['date' => [$past]]));
+	}
+}

tests/Core/Sharing/Feature/LabelShareFeatureTest.php

@@ -0,0 +1,38 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+
+namespace Tests\Core\Sharing\Feature;
+
+use OC\Core\Sharing\Feature\LabelShareFeature;
+use OCA\Sharing\Model\IShareFeature;
+use Test\TestCase;
+
+class LabelShareFeatureTest extends TestCase {
+	private IShareFeature $feature;
+
+	public function setUp(): void {
+		parent::setUp();
+
+		$this->feature = new LabelShareFeature();
+	}
+
+	public function testValidateProperties(): void {
+		$this->assertTrue($this->feature->validateProperties(['text' => ['a']]));
+
+		$this->assertFalse($this->feature->validateProperties([]));
+		$this->assertFalse($this->feature->validateProperties(['a' => ['a']]));
+		$this->assertFalse($this->feature->validateProperties(['text' => ['a'], 'a' => ['a']]));
+
+		$this->assertFalse($this->feature->validateProperties(['text' => []]));
+		$this->assertFalse($this->feature->validateProperties(['text' => ['a', 'b']]));
+
+		$this->assertFalse($this->feature->validateProperties(['text' => ['']]));
+	}
+}

tests/Core/Sharing/Feature/NoteShareFeatureTest.php

@@ -0,0 +1,38 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+
+namespace Tests\Core\Sharing\Feature;
+
+use OC\Core\Sharing\Feature\NoteShareFeature;
+use OCA\Sharing\Model\IShareFeature;
+use Test\TestCase;
+
+class NoteShareFeatureTest extends TestCase {
+	private IShareFeature $feature;
+
+	public function setUp(): void {
+		parent::setUp();
+
+		$this->feature = new NoteShareFeature();
+	}
+
+	public function testValidateProperties(): void {
+		$this->assertTrue($this->feature->validateProperties(['text' => ['a']]));
+
+		$this->assertFalse($this->feature->validateProperties([]));
+		$this->assertFalse($this->feature->validateProperties(['a' => ['a']]));
+		$this->assertFalse($this->feature->validateProperties(['text' => ['a'], 'a' => ['a']]));
+
+		$this->assertFalse($this->feature->validateProperties(['text' => []]));
+		$this->assertFalse($this->feature->validateProperties(['text' => ['a', 'b']]));
+
+		$this->assertFalse($this->feature->validateProperties(['text' => ['']]));
+	}
+}

tests/Core/Sharing/Feature/PasswordShareFeatureTest.php

@@ -0,0 +1,85 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+
+namespace Tests\Core\Sharing\Feature;
+
+use OC\Core\Sharing\Feature\PasswordShareFeature;
+use OCP\EventDispatcher\IEventDispatcher;
+use OCP\HintException;
+use OCP\Security\Events\ValidatePasswordPolicyEvent;
+use OCP\Security\IHasher;
+use OCP\Server;
+use Test\TestCase;
+
+class PasswordShareFeatureTest extends TestCase {
+	private PasswordShareFeature $feature;
+
+	private IEventDispatcher $eventDispatcher;
+
+	/**
+	 * @var callable(ValidatePasswordPolicyEvent):void $validatePasswordPolicyEventListener
+	 */
+	private $validatePasswordPolicyEventListener;
+
+
+	public function setUp(): void {
+		parent::setUp();
+
+		$this->feature = new PasswordShareFeature();
+
+		$this->eventDispatcher = Server::get(IEventDispatcher::class);
+		$this->validatePasswordPolicyEventListener = static function (ValidatePasswordPolicyEvent $event): void {
+			if ($event->getPassword() !== 'secure') {
+				throw new HintException('insecure');
+			}
+		};
+
+		$this->eventDispatcher->addListener(ValidatePasswordPolicyEvent::class, $this->validatePasswordPolicyEventListener);
+	}
+
+	protected function tearDown(): void {
+		$this->eventDispatcher->removeListener(ValidatePasswordPolicyEvent::class, $this->validatePasswordPolicyEventListener);
+
+		parent::tearDown();
+	}
+
+	public function testValidateProperties(): void {
+		$hash = Server::get(IHasher::class)->hash('secure');
+
+		$this->assertTrue($this->feature->validateProperties(['hash' => [$hash]]));
+		$this->assertTrue($this->feature->validateProperties(['password' => ['secure']]));
+
+		$this->assertFalse($this->feature->validateProperties([]));
+		$this->assertFalse($this->feature->validateProperties(['a' => []]));
+		$this->assertFalse($this->feature->validateProperties(['hash' => [$hash], 'a' => ['']]));
+		$this->assertFalse($this->feature->validateProperties(['password' => ['secure'], 'a' => ['']]));
+		$this->assertFalse($this->feature->validateProperties(['hash' => []]));
+		$this->assertFalse($this->feature->validateProperties(['password' => []]));
+		$this->assertFalse($this->feature->validateProperties(['hash' => ['']]));
+		$this->assertFalse($this->feature->validateProperties(['password' => ['']]));
+		$this->assertFalse($this->feature->validateProperties(['hash' => [$hash, $hash]]));
+		$this->assertFalse($this->feature->validateProperties(['password' => ['secure', 'secure']]));
+		$this->assertFalse($this->feature->validateProperties(['password' => ['insecure']]));
+	}
+
+	public function testModifyProperties(): void {
+		$properties = $this->feature->modifyProperties(['password' => ['123']]);
+		$this->assertEquals(['hash'], array_keys($properties));
+		$this->assertCount(1, $properties['hash']);
+		$this->assertTrue(Server::get(IHasher::class)->validate($properties['hash'][0]));
+		$this->assertTrue(Server::get(IHasher::class)->verify('123', $properties['hash'][0]));
+	}
+
+	public function testIsFiltered(): void {
+		$this->assertFalse($this->feature->isFiltered(null, '123', ['hash' => [Server::get(IHasher::class)->hash('123')]]));
+		$this->assertTrue($this->feature->isFiltered(null, '456', ['hash' => [Server::get(IHasher::class)->hash('123')]]));
+		$this->assertTrue($this->feature->isFiltered(null, null, ['hash' => [Server::get(IHasher::class)->hash('123')]]));
+	}
+}