diff --git a/cypress/e2e/api/SessionApi.spec.js b/cypress/e2e/api/SessionApi.spec.js
index 9ceb84a9f7b..8bcdd132dbb 100644
--- a/cypress/e2e/api/SessionApi.spec.js
+++ b/cypress/e2e/api/SessionApi.spec.js
@@ -37,7 +37,10 @@ describe('The session Api', function() {
 
 		it('returns connection', function() {
 			cy.openFileConnection({ fileId }).then(({ connection }) => {
-				cy.wrap(connection).its('documentId').should('be.greaterThan', 0)
+				cy.wrap(connection)
+					.its('documentId')
+					.then((id) => Number.parseInt(id))
+					.should('be.greaterThan', 1_000_000) // snowflake ids have more than 20 bit.
 				cy.closeConnection(connection)
 			})
 		})
diff --git a/cypress/e2e/api/UsersApi.spec.js b/cypress/e2e/api/UsersApi.spec.js
index c8ca4cda3d2..c7482f0f46e 100644
--- a/cypress/e2e/api/UsersApi.spec.js
+++ b/cypress/e2e/api/UsersApi.spec.js
@@ -22,7 +22,10 @@ describe('The user mention API', function() {
 	})
 
 	it('has a valid connection', function() {
-		cy.get('@connection').its('documentId').should('be.greaterThan', 0)
+		cy.get('@connection')
+			.its('documentId')
+			.then((id) => Number.parseInt(id))
+			.should('be.greaterThan', 1_000_000) // snowflake ids have more than 20 bit.
 		cy.closeConnection(this.connection)
 	})
 
diff --git a/lib/Command/ResetDocument.php b/lib/Command/ResetDocument.php
index a008dd14391..a04c095aa90 100644
--- a/lib/Command/ResetDocument.php
+++ b/lib/Command/ResetDocument.php
@@ -75,7 +75,9 @@ protected function execute(InputInterface $input, OutputInterface $output): int
 		if ($all) {
 			$fileIds = [];
 			foreach ($this->documentService->getAll() as $document) {
-				$fileIds[] = $document->getId();
+				if ($document->getContextType() === 'file') {
+					$fileIds[] = $document->getContextId();
+				}
 			}
 		} else {
 			$fileIds = [$fileId];
diff --git a/lib/Controller/AttachmentController.php b/lib/Controller/AttachmentController.php
index 69e659f495b..6af1ded8978 100644
--- a/lib/Controller/AttachmentController.php
+++ b/lib/Controller/AttachmentController.php
@@ -9,12 +9,16 @@
 namespace OCA\Text\Controller;
 
 use Exception;
+use OCA\Text\Context\ContextManager;
+use OCA\Text\Context\IContext;
+use OCA\Text\Db\DocumentMapper;
 use OCA\Text\Exception\InvalidSessionException;
 use OCA\Text\Exception\UploadException;
 use OCA\Text\Middleware\Attribute\RequireDocumentSession;
 use OCA\Text\Middleware\Attribute\RequireDocumentSessionOrUserOrShareToken;
 use OCA\Text\Service\AttachmentService;
 use OCP\AppFramework\ApiController;
+use OCP\AppFramework\Db\DoesNotExistException;
 use OCP\AppFramework\Http;
 use OCP\AppFramework\Http\Attribute\NoAdminRequired;
 use OCP\AppFramework\Http\Attribute\NoCSRFRequired;
@@ -25,6 +29,7 @@
 use OCP\Constants;
 use OCP\Files\IMimeTypeDetector;
 use OCP\Files\InvalidPathException;
+use OCP\Files\NotFoundException;
 use OCP\Files\NotPermittedException;
 use OCP\IL10N;
 use OCP\IRequest;
@@ -70,6 +75,8 @@ public function __construct(
 		private IMimeTypeDetector $mimeTypeDetector,
 		private AttachmentService $attachmentService,
 		private ShareManager $shareManager,
+		private DocumentMapper $documentMapper,
+		private ContextManager $contextManager,
 	) {
 		parent::__construct($appName, $request);
 	}
@@ -77,15 +84,15 @@ public function __construct(
 	#[NoAdminRequired]
 	#[PublicPage]
 	#[RequireDocumentSessionOrUserOrShareToken]
-	public function getAttachmentList(string $shareToken = ''): DataResponse {
-		$documentId = $this->getDocumentId();
+	public function getAttachmentList(int $fileId = 0, string $shareToken = ''): DataResponse {
+		$auth = $this->getAuth($shareToken, false);
+		$context = $this->getContext($auth, $fileId);
 		try {
 			$session = $this->getSession();
 		} catch (InvalidSessionException) {
 			$session = null;
 		}
-		$auth = $this->getAuth($shareToken, false);
-		$attachments = $this->attachmentService->getAttachmentList($documentId, $auth, $session);
+		$attachments = $this->attachmentService->getAttachmentList($context, $auth, $session);
 		return new DataResponse($attachments);
 	}
 
@@ -94,9 +101,9 @@ public function getAttachmentList(string $shareToken = ''): DataResponse {
 	#[RequireDocumentSession]
 	public function insertAttachmentFile(string $filePath): DataResponse {
 		$user = $this->getUser();
-
+		$context = $this->getContext($user);
 		try {
-			$insertResult = $this->attachmentService->insertAttachmentFile($this->getSession()->getDocumentId(), $filePath, $user);
+			$insertResult = $this->attachmentService->insertAttachmentFile($context, $filePath, $user);
 			if (isset($insertResult['error'])) {
 				return new DataResponse($insertResult, Http::STATUS_BAD_REQUEST);
 			} else {
@@ -112,8 +119,6 @@ public function insertAttachmentFile(string $filePath): DataResponse {
 	#[PublicPage]
 	#[RequireDocumentSession]
 	public function uploadAttachment(string $token = ''): DataResponse {
-		$documentId = $this->getSession()->getDocumentId();
-
 		try {
 			$file = $this->getUploadedFile('file');
 			if (isset($file['tmp_name'], $file['name'], $file['type'])) {
@@ -123,7 +128,8 @@ public function uploadAttachment(string $token = ''): DataResponse {
 				}
 				$newFileName = $file['name'];
 				$auth = $this->getAuth($token);
-				$uploadResult = $this->attachmentService->uploadAttachment($documentId, $newFileName, $newFileResource, $auth);
+				$context = $this->getContext($auth);
+				$uploadResult = $this->attachmentService->uploadAttachment($context, $newFileName, $newFileResource, $auth);
 				if (isset($uploadResult['error'])) {
 					return new DataResponse($uploadResult, Http::STATUS_BAD_REQUEST);
 				} else {
@@ -145,11 +151,11 @@ public function uploadAttachment(string $token = ''): DataResponse {
 	#[PublicPage]
 	#[RequireDocumentSession]
 	public function createAttachment(): DataResponse {
-		$documentId = $this->getSession()->getDocumentId();
+		$user = $this->getUser();
+		$context = $this->getContext($user);
 		try {
-			$user = $this->getUser();
 			$newFileName = $this->request->getParam('fileName', 'text.md');
-			$createResult = $this->attachmentService->createAttachmentFile($documentId, $newFileName, $user);
+			$createResult = $this->attachmentService->createAttachmentFile($context, $newFileName, $user);
 			if (isset($createResult['error'])) {
 				return new DataResponse($createResult, Http::STATUS_BAD_REQUEST);
 			} else {
@@ -200,13 +206,16 @@ private function getUploadedFile(string $key): array {
 	#[PublicPage]
 	#[NoCSRFRequired]
 	#[RequireDocumentSessionOrUserOrShareToken]
-	public function getImageFile(string $imageFileName, string $shareToken = '',
-		int $preferRawImage = 0): DataResponse|DataDownloadResponse {
-		$documentId = $this->getDocumentId();
-
+	public function getImageFile(
+		string $imageFileName,
+		string $shareToken = '',
+		int $preferRawImage = 0,
+		int $fileId = 0,
+	): DataResponse|DataDownloadResponse {
 		try {
 			$auth = $this->getAuth($shareToken, false);
-			$imageFile = $this->attachmentService->getImageFile($documentId, $imageFileName, $auth, $preferRawImage === 1);
+			$context = $this->getContext($auth, $fileId);
+			$imageFile = $this->attachmentService->getImageFile($context, $imageFileName, $preferRawImage === 1);
 			if ($imageFile !== null) {
 				$response = new DataDownloadResponse(
 					$imageFile->getContent(),
@@ -235,12 +244,15 @@ public function getImageFile(string $imageFileName, string $shareToken = '',
 	#[PublicPage]
 	#[NoCSRFRequired]
 	#[RequireDocumentSessionOrUserOrShareToken]
-	public function getMediaFile(string $mediaFileName, string $shareToken = ''): DataResponse|DataDownloadResponse {
-		$documentId = $this->getDocumentId();
-
+	public function getMediaFile(
+		string $mediaFileName,
+		string $shareToken = '',
+		int $fileId = 0,
+	): DataResponse|DataDownloadResponse {
 		try {
 			$auth = $this->getAuth($shareToken, false);
-			$mediaFile = $this->attachmentService->getMediaFile($documentId, $mediaFileName, $auth);
+			$context = $this->getContext($auth, $fileId);
+			$mediaFile = $this->attachmentService->getMediaFile($context, $mediaFileName);
 			return $mediaFile !== null
 				? new DataDownloadResponse(
 					$mediaFile->getContent(),
@@ -262,12 +274,11 @@ public function getMediaFile(string $mediaFileName, string $shareToken = ''): Da
 	#[PublicPage]
 	#[NoCSRFRequired]
 	#[RequireDocumentSessionOrUserOrShareToken]
-	public function getMediaFilePreview(string $mediaFileName, string $shareToken = '') {
-		$documentId = $this->getDocumentId();
-
+	public function getMediaFilePreview(string $mediaFileName, string $shareToken = '', int $fileId = 0) {
 		try {
 			$auth = $this->getAuth($shareToken, false);
-			$preview = $this->attachmentService->getMediaFilePreview($documentId, $mediaFileName, $auth);
+			$context = $this->getContext($auth, $fileId);
+			$preview = $this->attachmentService->getMediaFilePreview($context, $mediaFileName);
 			if ($preview === null) {
 				return new DataResponse('', Http::STATUS_NOT_FOUND);
 			}
@@ -286,6 +297,25 @@ public function getMediaFilePreview(string $mediaFileName, string $shareToken =
 		return new DataResponse('', Http::STATUS_NOT_FOUND);
 	}
 
+	private function getContext(IShare|IUser $auth, int $fileId = 0): IContext {
+		try {
+			$documentId = $this->getDocumentId();
+		} catch (InvalidSessionException $e) {
+			// Fallback for scenarios without a session. (MarkdownContentEditor with fileId)
+			return $this->contextManager->getContext('file', $fileId, $auth);
+		}
+		try {
+			$document = $this->documentMapper->find($documentId);
+		} catch (DoesNotExistException $e) {
+			throw new NotFoundException('Text file for document '
+				. $documentId
+				. ' was not found.', 0, $e);
+		}
+		$type = $document->getContextType();
+		$id = $document->getContextId();
+		return $this->contextManager->getContext($type, $id, $auth);
+	}
+
 	private function getAuth(string $shareToken, bool $updatePermissionRequired = true): IShare|IUser {
 		if ($shareToken !== '') {
 			try {
diff --git a/lib/Controller/ISessionAwareController.php b/lib/Controller/ISessionAwareController.php
index 87ebd86289a..566ddc85c2f 100644
--- a/lib/Controller/ISessionAwareController.php
+++ b/lib/Controller/ISessionAwareController.php
@@ -14,8 +14,8 @@
 interface ISessionAwareController {
 	public function getSession(): Session;
 	public function setSession(Session $session): void;
-	public function getDocumentId(): int;
-	public function setDocumentId(int $documentId): void;
+	public function getDocumentId(): string;
+	public function setDocumentId(string $documentId): void;
 	public function getDocument(): Document;
 	public function setDocument(Document $document): void;
 	public function getUser(): IUser;
diff --git a/lib/Controller/PublicSessionController.php b/lib/Controller/PublicSessionController.php
index 1b645edc344..6332b7dd3cb 100644
--- a/lib/Controller/PublicSessionController.php
+++ b/lib/Controller/PublicSessionController.php
@@ -84,7 +84,7 @@ public function create(string $token, ?string $filePath = null, ?string $baseVer
 
 	#[NoAdminRequired]
 	#[PublicPage]
-	public function close(int $documentId, int $sessionId, string $sessionToken): DataResponse {
+	public function close(string $documentId, int $sessionId, string $sessionToken): DataResponse {
 		return $this->apiService->close($documentId, $sessionId, $sessionToken, $this->getShare());
 	}
 
diff --git a/lib/Controller/SessionController.php b/lib/Controller/SessionController.php
index 1f66e72f3b0..c18ccb3ba1c 100644
--- a/lib/Controller/SessionController.php
+++ b/lib/Controller/SessionController.php
@@ -73,7 +73,7 @@ public function create(string $type, int $id, ?string $baseVersionEtag = null):
 
 	#[NoAdminRequired]
 	#[PublicPage]
-	public function close(int $documentId, int $sessionId, string $sessionToken): DataResponse {
+	public function close(string $documentId, int $sessionId, string $sessionToken): DataResponse {
 		// We also want this to work with a session that has already been closed.
 		// So we cannot rely on RequireDocumentSession to retrieve the user.
 		$user = $this->userSession->getUser();
@@ -127,7 +127,7 @@ public function save(int $version, string $autosaveContent, string $documentStat
 	#[RequireDocumentSession]
 	#[UserRateLimit(limit: 5, period: 120)]
 	public function mention(string $mention): DataResponse {
-		if ($this->getSession()->isGuest() && !$this->sessionService->isUserInDocument($this->getDocument()->getId(), $mention)) {
+		if ($this->getSession()->isGuest() && !$this->sessionService->isUserInDocument($this->getDocumentId(), $mention)) {
 			return new DataResponse([], 403);
 		}
 
diff --git a/lib/Controller/TSessionAwareController.php b/lib/Controller/TSessionAwareController.php
index 84afb600cb9..e3b9cf51aa6 100644
--- a/lib/Controller/TSessionAwareController.php
+++ b/lib/Controller/TSessionAwareController.php
@@ -16,7 +16,7 @@
 
 trait TSessionAwareController {
 	private ?Session $textSession = null;
-	private ?int $documentId = null;
+	private ?string $documentId = null;
 	private ?Document $document = null;
 	private ?IUser $user = null;
 
@@ -24,7 +24,7 @@ public function setSession(?Session $session): void {
 		$this->textSession = $session;
 	}
 
-	public function setDocumentId(int $documentId): void {
+	public function setDocumentId(string $documentId): void {
 		$this->documentId = $documentId;
 	}
 
@@ -50,7 +50,7 @@ public function getSession(): Session {
 	/**
 	 * @throws InvalidSessionException
 	 */
-	public function getDocumentId(): int {
+	public function getDocumentId(): string {
 		if ($this->documentId === null) {
 			throw new InvalidSessionException();
 		}
diff --git a/lib/Cron/Cleanup.php b/lib/Cron/Cleanup.php
index aadcb115a9e..bffe1dc37d6 100644
--- a/lib/Cron/Cleanup.php
+++ b/lib/Cron/Cleanup.php
@@ -34,7 +34,9 @@ public function __construct(
 	protected function run($argument): void {
 		$this->logger->debug('Run cleanup job for text documents');
 		foreach ($this->documentService->getAllWithNoActiveSession() as $document) {
-			$this->attachmentService->cleanupAttachments($document->getId());
+			if ($document->getContextType() === 'file') {
+				$this->attachmentService->cleanupAttachments($document->getContextId());
+			}
 		}
 
 		$this->logger->debug('Run cleanup job for text sessions');
diff --git a/lib/Db/Document.php b/lib/Db/Document.php
index 58c0f227265..2e481cf36d4 100644
--- a/lib/Db/Document.php
+++ b/lib/Db/Document.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * SPDX-FileCopyrightText: 2019 Nextcloud GmbH and Nextcloud contributors
  * SPDX-License-Identifier: AGPL-3.0-or-later
@@ -7,10 +9,10 @@
 
 namespace OCA\Text\Db;
 
-use OCP\AppFramework\Db\Entity;
+use OCP\AppFramework\Db\SnowflakeAwareEntity;
+use OCP\DB\Types;
 
 /**
- * @method getId(): int
  * @method getCurrentVersion(): int
  * @method setCurrentVersion(int $version): void
  * @method getLastSavedVersion(): int
@@ -30,7 +32,10 @@
  * @method getContextId(): int
  * @method setContextId(int $contextId): void
  */
-class Document extends Entity implements \JsonSerializable {
+class Document extends SnowflakeAwareEntity implements \JsonSerializable {
+	/** @var ?string $id
+	 * @psalm-suppress NonInvariantDocblockPropertyType
+	 */
 	public $id = null;
 	// TODO: Remove obsolete field `currentVersion`
 	protected int $currentVersion = 0;
@@ -44,18 +49,19 @@ class Document extends Entity implements \JsonSerializable {
 	protected int $contextId = 0;
 
 	public function __construct() {
-		$this->addType('currentVersion', 'integer');
-		$this->addType('lastSavedVersion', 'integer');
-		$this->addType('lastSavedVersionTime', 'integer');
-		$this->addType('initialVersion', 'integer');
-		$this->addType('checksum', 'string');
-		$this->addType('contextType', 'string');
-		$this->addType('contextId', 'integer');
+		$this->addType('id', Types::STRING);
+		$this->addType('currentVersion', Types::INTEGER);
+		$this->addType('lastSavedVersion', Types::INTEGER);
+		$this->addType('lastSavedVersionTime', Types::INTEGER);
+		$this->addType('initialVersion', Types::INTEGER);
+		$this->addType('checksum', Types::STRING);
+		$this->addType('contextType', Types::STRING);
+		$this->addType('contextId', Types::INTEGER);
 	}
 
 	public function jsonSerialize(): array {
 		return [
-			'id' => $this->getId(),
+			'id' => $this->id,
 			'lastSavedVersion' => $this->lastSavedVersion,
 			'lastSavedVersionTime' => $this->lastSavedVersionTime,
 			'baseVersionEtag' => $this->baseVersionEtag,
diff --git a/lib/Db/DocumentMapper.php b/lib/Db/DocumentMapper.php
index f94c0564faf..825958df6d9 100644
--- a/lib/Db/DocumentMapper.php
+++ b/lib/Db/DocumentMapper.php
@@ -24,7 +24,7 @@ public function __construct(IDBConnection $db) {
 	 * @return Document
 	 * @throws DoesNotExistException
 	 */
-	public function find(int $documentId): Document {
+	public function find(string $documentId): Document {
 
 		/* @var $qb IQueryBuilder */
 		$qb = $this->db->getQueryBuilder();
diff --git a/lib/Db/Session.php b/lib/Db/Session.php
index 7bcf39d6c48..74b61fc1f0c 100644
--- a/lib/Db/Session.php
+++ b/lib/Db/Session.php
@@ -10,6 +10,7 @@
 use JsonSerializable;
 use OCA\Text\Exception\InvalidSessionException;
 use OCP\AppFramework\Db\Entity;
+use OCP\DB\Types;
 
 /**
  * @method void setUserId(?string $userId)
@@ -23,8 +24,8 @@
  * @method void setLastAwarenessMessage(string $message)
  * @method int getLastContact()
  * @method void setLastContact(int $getTime)
- * @method int getDocumentId()
- * @method void setDocumentId(int $documentId)
+ * @method string getDocumentId()
+ * @method void setDocumentId(string $documentId)
  */
 class Session extends Entity implements JsonSerializable {
 	public $id;
@@ -34,11 +35,11 @@ class Session extends Entity implements JsonSerializable {
 	protected ?string $guestName = null;
 	protected ?string $lastAwarenessMessage = '';
 	protected int $lastContact = 0;
-	protected int $documentId = 0;
+	protected string $documentId = '';
 
 	public function __construct() {
-		$this->addType('documentId', 'integer');
-		$this->addType('lastContact', 'integer');
+		$this->addType('documentId', Types::STRING);
+		$this->addType('lastContact', Types::INTEGER);
 	}
 
 	public function isGuest(): bool {
diff --git a/lib/Db/SessionMapper.php b/lib/Db/SessionMapper.php
index cfe596447d0..9feb630ccb7 100644
--- a/lib/Db/SessionMapper.php
+++ b/lib/Db/SessionMapper.php
@@ -37,7 +37,7 @@ public function findAllDocuments(): array {
 	 * @return Session
 	 * @throws DoesNotExistException
 	 */
-	public function find(int $documentId, int $sessionId, string $token): Session {
+	public function find(string $documentId, int $sessionId, string $token): Session {
 		/* @var $qb IQueryBuilder */
 		$qb = $this->db->getQueryBuilder();
 		$result = $qb->select('*')
@@ -60,7 +60,7 @@ public function find(int $documentId, int $sessionId, string $token): Session {
 	 *
 	 * @psalm-return array<Session>
 	 */
-	public function findAll(int $documentId): array {
+	public function findAll(string $documentId): array {
 		$qb = $this->db->getQueryBuilder();
 		$qb->select('id', 'color', 'document_id', 'last_awareness_message', 'last_contact', 'user_id', 'guest_name')
 			->from($this->getTableName())
@@ -69,7 +69,7 @@ public function findAll(int $documentId): array {
 		return $this->findEntities($qb);
 	}
 
-	public function countAll(int $documentId): int {
+	public function countAll(string $documentId): int {
 		$qb = $this->db->getQueryBuilder();
 		$qb->select('id', 'color', 'document_id', 'last_awareness_message', 'last_contact', 'user_id', 'guest_name')
 			->from($this->getTableName())
@@ -85,7 +85,7 @@ public function countAll(int $documentId): int {
 	 *
 	 * @psalm-return array<Session>
 	 */
-	public function findAllActive(int $documentId): array {
+	public function findAllActive(string $documentId): array {
 		$qb = $this->db->getQueryBuilder();
 		$qb->select('id', 'color', 'document_id', 'last_awareness_message', 'last_contact', 'user_id', 'guest_name')
 			->from($this->getTableName())
@@ -109,7 +109,7 @@ public function findAllInactive(): array {
 		return $this->findEntities($qb);
 	}
 
-	public function deleteInactiveWithoutSteps(?int $documentId = null): int {
+	public function deleteInactiveWithoutSteps(?string $documentId = null): int {
 		$lastContact = time() - SessionService::SESSION_VALID_TIME;
 
 		$inactiveSessionBuilder = $this->db->getQueryBuilder();
@@ -217,7 +217,7 @@ public function deleteOrphanedSteps(int $ageInSeconds): int {
 		return $deletedCount;
 	}
 
-	public function deleteByDocumentId(int $documentId): int {
+	public function deleteByDocumentId(string $documentId): int {
 		$qb = $this->db->getQueryBuilder();
 		$qb->delete($this->getTableName())
 			->where($qb->expr()->eq('document_id', $qb->createNamedParameter($documentId)));
@@ -230,7 +230,7 @@ public function clearAll(): void {
 			->executeStatement();
 	}
 
-	public function isUserInDocument(int $documentId, string $userId): bool {
+	public function isUserInDocument(string $documentId, string $userId): bool {
 		$qb = $this->db->getQueryBuilder();
 		$result = $qb->select('*')
 			->from($this->getTableName())
diff --git a/lib/Db/Step.php b/lib/Db/Step.php
index 57b6b2bf2d3..c687974b28f 100644
--- a/lib/Db/Step.php
+++ b/lib/Db/Step.php
@@ -9,6 +9,7 @@
 
 use JsonSerializable;
 use OCP\AppFramework\Db\Entity;
+use OCP\DB\Types;
 
 /**
  * @method getData(): string
@@ -17,8 +18,8 @@
  * @method setVersion(int $version): void
  * @method getSessionId(): int
  * @method setSessionId(int $sessionId): void
- * @method getDocumentId(): int
- * @method setDocumentId(int $documentId): void
+ * @method getDocumentId(): string
+ * @method setDocumentId(string $documentId): void
  * @method getTimestamp(): int
  * @method setTimestamp(int $timestam): void
  */
@@ -35,14 +36,14 @@ class Step extends Entity implements JsonSerializable {
 	protected string $data = '';
 	protected int $version = 0;
 	protected int $sessionId = 0;
-	protected int $documentId = 0;
+	protected string $documentId = '';
 	protected int $timestamp = 0;
 
 	public function __construct() {
-		$this->addType('version', 'integer');
-		$this->addType('documentId', 'integer');
-		$this->addType('sessionId', 'integer');
-		$this->addType('timestamp', 'integer');
+		$this->addType('version', Types::INTEGER);
+		$this->addType('documentId', Types::STRING);
+		$this->addType('sessionId', Types::INTEGER);
+		$this->addType('timestamp', Types::INTEGER);
 	}
 
 	public function jsonSerialize(): array {
diff --git a/lib/Db/StepMapper.php b/lib/Db/StepMapper.php
index 26339b0912b..960428ac608 100644
--- a/lib/Db/StepMapper.php
+++ b/lib/Db/StepMapper.php
@@ -20,7 +20,7 @@ public function __construct(IDBConnection $db) {
 	/**
 	 * @return Step[]
 	 */
-	public function find(int $documentId, int $fromVersion): array {
+	public function find(string $documentId, int $fromVersion): array {
 		/* @var $qb IQueryBuilder */
 		$qb = $this->db->getQueryBuilder();
 		$qb->select('*')
@@ -38,7 +38,7 @@ public function find(int $documentId, int $fromVersion): array {
 	/**
 	 * @psalm-return ?positive-int
 	 */
-	public function getLatestVersion(int $documentId): ?int {
+	public function getLatestVersion(string $documentId): ?int {
 		/* @var $qb IQueryBuilder */
 		$qb = $this->db->getQueryBuilder();
 		$result = $qb->select('id')
@@ -56,7 +56,7 @@ public function getLatestVersion(int $documentId): ?int {
 		return $data['id'];
 	}
 
-	public function getBeforeVersion(int $documentId, int $version, int $offset): int {
+	public function getBeforeVersion(string $documentId, int $version, int $offset): int {
 		$qb = $this->db->getQueryBuilder();
 		$result = $qb->select('id')
 			->from($this->getTableName())
@@ -75,7 +75,7 @@ public function getBeforeVersion(int $documentId, int $version, int $offset): in
 		return $data['id'];
 	}
 
-	public function deleteAll(int $documentId): void {
+	public function deleteAll(string $documentId): void {
 		$qb = $this->db->getQueryBuilder();
 		$qb->delete($this->getTableName())
 			->where($qb->expr()->eq('document_id', $qb->createNamedParameter($documentId)))
@@ -89,7 +89,7 @@ public function clearAll(): void {
 	}
 
 	// not in use right now
-	public function deleteBeforeVersion(int $documentId, int $version): int {
+	public function deleteBeforeVersion(string $documentId, int $version): int {
 		$qb = $this->db->getQueryBuilder();
 		return $qb->delete($this->getTableName())
 			->where($qb->expr()->eq('document_id', $qb->createNamedParameter($documentId)))
@@ -97,7 +97,7 @@ public function deleteBeforeVersion(int $documentId, int $version): int {
 			->executeStatement();
 	}
 
-	public function deleteAfterVersion(int $documentId, int $version): int {
+	public function deleteAfterVersion(string $documentId, int $version): int {
 		$qb = $this->db->getQueryBuilder();
 		return $qb->delete($this->getTableName())
 			->where($qb->expr()->eq('document_id', $qb->createNamedParameter($documentId)))
diff --git a/lib/Middleware/SessionMiddleware.php b/lib/Middleware/SessionMiddleware.php
index 890d2d3f308..050cc9ede55 100644
--- a/lib/Middleware/SessionMiddleware.php
+++ b/lib/Middleware/SessionMiddleware.php
@@ -77,7 +77,7 @@ public function beforeController(Controller $controller, string $methodName): vo
 	 * @throws InvalidDocumentBaseVersionEtagException
 	 */
 	private function assertDocumentBaseVersionEtag(): void {
-		$documentId = (int)$this->request->getParam('documentId');
+		$documentId = (string)$this->request->getParam('documentId');
 		$baseVersionEtag = $this->request->getParam('baseVersionEtag');
 
 		$document = $this->documentService->getDocument($documentId);
@@ -91,7 +91,7 @@ private function assertDocumentBaseVersionEtag(): void {
 	 * @throws AccountDisabledException
 	 */
 	private function assertDocumentSession(ISessionAwareController $controller): void {
-		$documentId = (int)$this->request->getParam('documentId');
+		$documentId = (string)$this->request->getParam('documentId');
 		$sessionId = (int)$this->request->getParam('sessionId');
 		$token = (string)$this->request->getParam('sessionToken');
 
@@ -124,7 +124,7 @@ private function assertDocumentSession(ISessionAwareController $controller): voi
 	 * @throws InvalidSessionException
 	 */
 	private function assertUserOrShareToken(ISessionAwareController $controller): void {
-		$documentId = (int)$this->request->getParam('documentId');
+		$documentId = (string)$this->request->getParam('documentId');
 		$shareToken = (string)$this->request->getParam('shareToken');
 		$user = $this->userSession->getUser();
 
diff --git a/lib/Migration/Version090000Date20260817110024.php b/lib/Migration/Version090000Date20260817110024.php
index 627d673b141..ea3de1160cb 100644
--- a/lib/Migration/Version090000Date20260817110024.php
+++ b/lib/Migration/Version090000Date20260817110024.php
@@ -40,12 +40,6 @@ public function changeSchema(IOutput $output, Closure $schemaClosure, array $opt
 			]);
 		}
 
-		$column = $table->getColumn('id');
-		if (!$column->getAutoincrement()) {
-			$table->modifyColumn('id', [
-				'autoincrement' => true,
-			]);
-		}
 		return $schema;
 	}
 }
diff --git a/lib/Service/ApiService.php b/lib/Service/ApiService.php
index 8390d8f45dd..83ee665ced7 100644
--- a/lib/Service/ApiService.php
+++ b/lib/Service/ApiService.php
@@ -28,6 +28,7 @@
 use OCP\IUser;
 use OCP\Share\IShare;
 use Psr\Log\LoggerInterface;
+use RuntimeException;
 
 class ApiService {
 	public function __construct(
@@ -52,11 +53,15 @@ public function create(IContext $context, ?string $baseVersionEtag, ?string $gue
 
 		try {
 			$document = $this->documentService->getOrCreateDocument($document);
+			$documentId = $document->id;
+			if ($documentId === null) {
+				throw new RuntimeException('Persisted document must have an id.');
+			}
 		} catch (Exception $e) {
 			$this->logger->error($e->getMessage(), ['exception' => $e]);
 			return new DataResponse(['error' => 'Failed to create the document session'], Http::STATUS_INTERNAL_SERVER_ERROR);
 		}
-		$documentData = $this->documentService->getDocumentData($document);
+		$documentData = $this->documentService->getDocumentData($documentId, $document);
 
 		if ($baseVersionEtag !== null && $baseVersionEtag !== $document->getBaseVersionEtag()) {
 			$error = $this->l10n->t('Editing session has expired. Please reload the page.');
@@ -64,8 +69,8 @@ public function create(IContext $context, ?string $baseVersionEtag, ?string $gue
 		}
 
 		$sessionInfo = $context->prepareSession($documentData);
-		$this->sessionService->removeInactiveSessionsWithoutSteps($document->id);
-		$session = $this->sessionService->initSession($document->id, $guestName);
+		$this->sessionService->removeInactiveSessionsWithoutSteps($documentId);
+		$session = $this->sessionService->initSession($documentId, $guestName);
 		$displayName = $this->sessionService->getNameForSession($session);
 
 		$newSession = new NewSessionData(
@@ -80,7 +85,7 @@ public function create(IContext $context, ?string $baseVersionEtag, ?string $gue
 		);
 	}
 
-	public function close(int $documentId, int $sessionId, string $sessionToken, IShare|IUser $auth): DataResponse {
+	public function close(string $documentId, int $sessionId, string $sessionToken, IShare|IUser $auth): DataResponse {
 		$this->sessionService->closeSession($documentId, $sessionId, $sessionToken);
 		$this->sessionService->removeInactiveSessionsWithoutSteps($documentId);
 		$activeSessions = $this->sessionService->getActiveSessions($documentId);
@@ -100,6 +105,9 @@ public function close(int $documentId, int $sessionId, string $sessionToken, ISh
 	 * @throws NotFoundException
 	 */
 	public function push(Session $session, Document $document, int $version, array $steps, string $awareness, ?int $recoveryAttempt, IShare|IUser $auth): DataResponse {
+		if ($document->id === null) {
+			throw new RuntimeException('Document needs to have an id to push.');
+		}
 		try {
 			$session = $this->sessionService->updateSessionAwareness($session, $awareness);
 		} catch (DoesNotExistException $e) {
@@ -108,7 +116,7 @@ public function push(Session $session, Document $document, int $version, array $
 		}
 		try {
 			$result = $this->documentService->addStep($document, $session, $steps, $version, $recoveryAttempt, $auth);
-			$this->addToPushQueue($document, [$awareness, ...array_values($steps)]);
+			$this->addToPushQueue($document->id, [$awareness, ...array_values($steps)]);
 		} catch (InvalidArgumentException $e) {
 			return new DataResponse(['error' => $e->getMessage()], Http::STATUS_UNPROCESSABLE_ENTITY);
 		} catch (DoesNotExistException) {
@@ -120,12 +128,12 @@ public function push(Session $session, Document $document, int $version, array $
 		return new DataResponse($result);
 	}
 
-	private function addToPushQueue(Document $document, array $steps): void {
+	private function addToPushQueue(string $documentId, array $steps): void {
 		if ($this->queue === null || !$this->configService->isNotifyPushSyncEnabled()) {
 			return;
 		}
 
-		$sessions = $this->sessionService->getActiveSessions($document->id);
+		$sessions = $this->sessionService->getActiveSessions($documentId);
 		$userIds = array_values(array_filter(array_unique(
 			array_map(fn ($session): ?string => $session['userId'], $sessions)
 		)));
@@ -134,7 +142,7 @@ private function addToPushQueue(Document $document, array $steps): void {
 				'user' => $userId,
 				'message' => 'text_steps',
 				'body' => [
-					'documentId' => $document->getId(),
+					'documentId' => $documentId,
 					'steps' => array_values(array_filter($steps)),
 				],
 			]);
@@ -142,6 +150,9 @@ private function addToPushQueue(Document $document, array $steps): void {
 	}
 
 	public function sync(Document $document, IShare|IUser $auth, int $version = 0): DataResponse {
+		if ($document->id === null) {
+			throw new RuntimeException('Document needs to have an id to sync.');
+		}
 		$result = [];
 		try {
 			$result = [
diff --git a/lib/Service/AttachmentService.php b/lib/Service/AttachmentService.php
index ad7685eddcb..bc3b2953211 100755
--- a/lib/Service/AttachmentService.php
+++ b/lib/Service/AttachmentService.php
@@ -12,11 +12,9 @@
 use OC\User\NoUserException;
 use OCA\DAV\Connector\Sabre\PublicAuth;
 use OCA\Files_Sharing\SharedStorage;
-use OCA\Text\Context\ContextManager;
+use OCA\Text\Context\IContext;
 use OCA\Text\Controller\AttachmentController;
-use OCA\Text\Db\DocumentMapper;
 use OCA\Text\Db\Session;
-use OCP\AppFramework\Db\DoesNotExistException;
 use OCP\Files\File;
 use OCP\Files\Folder;
 use OCP\Files\IFilenameValidator;
@@ -31,7 +29,6 @@
 use OCP\ISession;
 use OCP\IURLGenerator;
 use OCP\IUser;
-use OCP\IUserManager;
 use OCP\Lock\LockedException;
 use OCP\Share\Exceptions\ShareNotFound;
 use OCP\Share\IManager as ShareManager;
@@ -48,9 +45,6 @@ public function __construct(
 		private IFilenameValidator $filenameValidator,
 		private IFilesMetadataManager $filesMetadataManager,
 		private ISession $session,
-		private DocumentMapper $documentMapper,
-		private ContextManager $contextManager,
-		private IUserManager $userManager,
 	) {
 	}
 
@@ -62,8 +56,8 @@ public function __construct(
 	 * @throws NotFoundException
 	 * @throws NotPermittedException
 	 */
-	public function getImageFile(int $documentId, string $imageFileName, IShare|IUser $auth, bool $preferRawImage): File|ISimpleFile|null {
-		$textFile = $this->getTextFile($documentId, $auth);
+	public function getImageFile(IContext $context, string $imageFileName, bool $preferRawImage): File|ISimpleFile|null {
+		$textFile = $this->getTextFile($context);
 		return $this->getImageFileContent($imageFileName, $textFile, $preferRawImage);
 	}
 
@@ -102,8 +96,8 @@ private function getImageFileContent(string $imageFileName, File $textFile, bool
 	 * @throws NotPermittedException
 	 * @throws NoUserException
 	 */
-	public function getMediaFile(int $documentId, string $mediaFileName, IShare|IUser $auth): ?File {
-		$textFile = $this->getTextFile($documentId, $auth);
+	public function getMediaFile(IContext $context, string $mediaFileName): ?File {
+		$textFile = $this->getTextFile($context);
 		return $this->getMediaFullFile($mediaFileName, $textFile);
 	}
 
@@ -128,8 +122,8 @@ private function getMediaFullFile(string $mediaFileName, File $textFile): ?File
 	 * @throws InvalidPathException
 	 * @throws NoUserException
 	 */
-	public function getMediaFilePreview(int $documentId, string $mediaFileName, IShare|IUser $auth): ?array {
-		$textFile = $this->getTextFile($documentId, $auth);
+	public function getMediaFilePreview(IContext $context, string $mediaFileName): ?array {
+		$textFile = $this->getTextFile($context);
 		return $this->getMediaFilePreviewFile($mediaFileName, $textFile);
 	}
 
@@ -170,8 +164,8 @@ private function getMediaFilePreviewFile(string $mediaFileName, File $textFile):
 	 * @throws NotFoundException
 	 * @throws NotPermittedException
 	 */
-	public function getAttachmentList(int $documentId, IShare|IUser $auth, ?Session $session = null): array {
-		$textFile = $this->getTextFile($documentId, $auth);
+	public function getAttachmentList(IContext $context, IShare|IUser $auth, ?Session $session = null): array {
+		$textFile = $this->getTextFile($context);
 		try {
 
 			$attachmentDir = $this->getAttachmentDirectoryForFile($textFile);
@@ -183,8 +177,8 @@ public function getAttachmentList(int $documentId, IShare|IUser $auth, ?Session
 			? '&shareToken=' . rawurlencode($auth->getToken())
 			: '';
 		$urlParamsBase = $session
-			? '?documentId=' . $documentId . '&sessionId=' . $session->getId() . '&sessionToken=' . rawurlencode($session->getToken()) . $shareTokenUrlString
-			: '?documentId=' . $documentId . $shareTokenUrlString;
+			? '?documentId=' . $session->getDocumentId() . '&sessionId=' . $session->getId() . '&sessionToken=' . rawurlencode($session->getToken()) . $shareTokenUrlString
+			: '?fileId=' . $context->getId() . $shareTokenUrlString;
 
 		$attachments = [];
 
@@ -242,7 +236,7 @@ public function getAttachmentList(int $documentId, IShare|IUser $auth, ?Session
 	 * @throws InvalidPathException
 	 * @throws NoUserException
 	 */
-	public function uploadAttachment(int $documentId, string $newFileName, $newFileResource, IShare|IUser $auth): array {
+	public function uploadAttachment(IContext $context, string $newFileName, $newFileResource, IShare|IUser $auth): array {
 
 		if ($auth instanceof IShare && $auth->getPassword() !== null) {
 			$key = PublicAuth::DAV_AUTHENTICATED;
@@ -261,7 +255,7 @@ public function uploadAttachment(int $documentId, string $newFileName, $newFileR
 			}
 		}
 
-		$textFile = $this->getTextFile($documentId, $auth);
+		$textFile = $this->getTextFile($context);
 		$saveDir = $this->getAttachmentDirectoryForFile($textFile, true);
 		$fileName = self::getUniqueFileName($saveDir, $newFileName);
 		$this->filenameValidator->validateFilename($fileName);
@@ -270,7 +264,6 @@ public function uploadAttachment(int $documentId, string $newFileName, $newFileR
 			'name' => $fileName,
 			'dirname' => $saveDir->getName(),
 			'id' => $savedFile->getId(),
-			'documentId' => $documentId,
 		];
 	}
 
@@ -282,8 +275,8 @@ public function uploadAttachment(int $documentId, string $newFileName, $newFileR
 	 * @throws InvalidPathException
 	 * @throws NoUserException
 	 */
-	public function insertAttachmentFile(int $documentId, string $path, IUser $user): array {
-		$textFile = $this->getTextFile($documentId, $user);
+	public function insertAttachmentFile(IContext $context, string $path, IUser $user): array {
+		$textFile = $this->getTextFile($context);
 		if (!$textFile->isUpdateable()) {
 			throw new NotPermittedException('No write permissions');
 		}
@@ -296,7 +289,6 @@ public function insertAttachmentFile(int $documentId, string $path, IUser $user)
 			'name' => $fileName,
 			'dirname' => $saveDir->getName(),
 			'id' => $targetFile->getId(),
-			'documentId' => $documentId,
 			'mimetype' => $targetFile->getMimetype(),
 		];
 	}
@@ -309,8 +301,8 @@ public function insertAttachmentFile(int $documentId, string $path, IUser $user)
 	 * @throws InvalidPathException
 	 * @throws NoUserException
 	 */
-	public function createAttachmentFile(int $documentId, string $newFileName, IUser $user): array {
-		$textFile = $this->getTextFile($documentId, $user);
+	public function createAttachmentFile(IContext $context, string $newFileName, IUser $user): array {
+		$textFile = $this->getTextFile($context);
 		if (!$textFile->isUpdateable()) {
 			throw new NotPermittedException('No write permissions');
 		}
@@ -321,7 +313,6 @@ public function createAttachmentFile(int $documentId, string $newFileName, IUser
 			'name' => $newFile->getName(),
 			'dirname' => $saveDir->getName(),
 			'id' => $newFile->getId(),
-			'documentId' => $documentId,
 			'mimetype' => $newFile->getMimetype(),
 		];
 	}
@@ -420,24 +411,14 @@ private function isDownloadDisabled(File $file): bool {
 	 * @throws NotFoundException
 	 * @throws NotPermittedException
 	 */
-	private function getTextFile(int $documentId, IShare|IUser $auth): File {
-		try {
-			$document = $this->documentMapper->find($documentId);
-		} catch (DoesNotExistException $e) {
-			throw new NotFoundException('Text file for document '
-				. $documentId
-				. ' was not found.', 0, $e);
-		}
-		$type = $document->getContextType();
-		$id = $document->getContextId();
-		$context = $this->contextManager->getContext($type, $id, $auth);
+	private function getTextFile(IContext $context): File {
 		$file = $context->getFile();
 		if ($file instanceof File && !$this->isDownloadDisabled($file)) {
 			return $file;
 		}
-		throw new NotFoundException('Text file for document '
-			. $documentId
-			. ' was not found.'
+		throw new NotFoundException('Text file for '
+			. $context->toString()
+			. ' was not found or download is disabled.'
 		);
 	}
 
diff --git a/lib/Service/DocumentService.php b/lib/Service/DocumentService.php
index f3114fe9c7e..995ff1731d2 100644
--- a/lib/Service/DocumentService.php
+++ b/lib/Service/DocumentService.php
@@ -41,6 +41,7 @@
 use OCP\Lock\LockedException;
 use OCP\Share\IShare;
 use Psr\Log\LoggerInterface;
+use RuntimeException;
 use function json_encode;
 
 class DocumentService {
@@ -80,7 +81,7 @@ public function __construct(
 		}
 	}
 
-	public function getDocument(int $id): ?Document {
+	public function getDocument(string $id): ?Document {
 		try {
 			return $this->documentMapper->find($id);
 		} catch (DoesNotExistException|NotFoundException) {
@@ -111,6 +112,7 @@ public function getOrCreateDocument(Document $document): Document {
 
 		$this->logger->info('Create new document of ' . $document->toString());
 		try {
+			$document->generateId();
 			/** @var Document $document */
 			$document = $this->documentMapper->insert($document);
 			$this->cache->set('document-version-' . $document->id, 0);
@@ -127,12 +129,12 @@ public function getOrCreateDocument(Document $document): Document {
 		return $document;
 	}
 
-	public function getDocumentData(Document $document): DocumentData {
+	public function getDocumentData(string $documentId, Document $document): DocumentData {
 		$documentState = null;
 		if ($document->getLastSavedVersion() > 0) {
 			$this->logger->debug('Loading saved document state for ' . $document->toString());
 			try {
-				$stateFile = $this->getStateFile($document->id);
+				$stateFile = $this->getStateFile($documentId);
 				$documentState = $stateFile->getContent();
 			} catch (NotFoundException) {
 				// If we have no state file we need to load the content from the file
@@ -150,11 +152,11 @@ public function getDocumentData(Document $document): DocumentData {
 	}
 
 	/**
-	 * @param int $documentId
+	 * @param string $documentId
 	 * @return ISimpleFile
 	 * @throws NotFoundException
 	 */
-	public function getStateFile(int $documentId): ISimpleFile {
+	public function getStateFile(string $documentId): ISimpleFile {
 		$filename = $documentId . '.yjs';
 		if (!$this->ensureDocumentsFolder()) {
 			throw new NotFoundException('No app data folder present for text documents');
@@ -190,21 +192,21 @@ public function updateDocument(Document $document): void {
 	}
 
 	/**
-	 * @param int $documentId
+	 * @param string $documentId
 	 *
 	 * @return ISimpleFile
 	 * @throws NotPermittedException
 	 */
-	public function createStateFile(int $documentId): ISimpleFile {
+	public function createStateFile(string $documentId): ISimpleFile {
 		$filename = $documentId . '.yjs';
 		return $this->appData->getFolder('documents')->newFile($filename);
 	}
 
 	/**
-	 * @param int $documentId
+	 * @param string $documentId
 	 * @param string $content
 	 */
-	public function writeDocumentState(int $documentId, string $content): void {
+	public function writeDocumentState(string $documentId, string $content): void {
 		try {
 			$documentStateFile = $this->getStateFile($documentId);
 		} catch (NotFoundException) {
@@ -245,7 +247,7 @@ public function addStep(Document $document, Session $session, array $steps, int
 			$id = $document->getContextId();
 			$context = $this->contextManager->getContext($type, $id, $auth);
 			if (!$context->isReadOnly()) {
-				$this->insertSteps($document, $session, $stepsToInsert);
+				$this->insertSteps($documentId, $session, $stepsToInsert);
 			}
 		}
 
@@ -289,7 +291,7 @@ public function addStep(Document $document, Session $session, array $steps, int
 	}
 
 	/**
-	 * @param Document $document
+	 * @param string $documentId
 	 * @param Session $session
 	 * @param Step[] $steps
 	 *
@@ -298,34 +300,34 @@ public function addStep(Document $document, Session $session, array $steps, int
 	 *
 	 * @psalm-param non-empty-list<mixed> $steps
 	 */
-	private function insertSteps(Document $document, Session $session, array $steps): void {
+	private function insertSteps(string $documentId, Session $session, array $steps): void {
 		$stepsVersion = null;
 		try {
 			$stepsJson = json_encode($steps, JSON_THROW_ON_ERROR);
-			$stepsVersion = $this->stepMapper->getLatestVersion($document->getId());
+			$stepsVersion = $this->stepMapper->getLatestVersion($documentId);
 			$step = new Step();
 			$step->setData($stepsJson);
 			$step->setSessionId($session->getId());
-			$step->setDocumentId($document->getId());
+			$step->setDocumentId($documentId);
 			$step->setVersion(Step::VERSION_STORED_IN_ID);
 			$step->setTimestamp(time());
 			$step = $this->stepMapper->insert($step);
 			$newVersion = $step->getId();
-			$this->logger->debug('Adding steps to ' . $document->getId() . ": bumping version from $stepsVersion to $newVersion");
-			$this->cache->set('document-version-' . $document->getId(), $newVersion);
+			$this->logger->debug('Adding steps to ' . $documentId . ": bumping version from $stepsVersion to $newVersion");
+			$this->cache->set('document-version-' . $documentId, $newVersion);
 			// TODO write steps to cache for quicker reading
 		} catch (\Throwable $e) {
 			if ($stepsVersion !== null) {
 				$this->logger->error('This should never happen. An error occurred when storing the version, trying to recover the last stable one', ['exception' => $e]);
-				$this->cache->set('document-version-' . $document->getId(), $stepsVersion);
-				$this->stepMapper->deleteAfterVersion($document->getId(), $stepsVersion);
+				$this->cache->set('document-version-' . $documentId, $stepsVersion);
+				$this->stepMapper->deleteAfterVersion($documentId, $stepsVersion);
 			}
 			throw $e;
 		}
 	}
 
 	/** @return Step[] */
-	public function getSteps(int $documentId, int $lastVersion): array {
+	public function getSteps(string $documentId, int $lastVersion): array {
 		if ($lastVersion === $this->cache->get('document-version-' . $documentId)) {
 			return [];
 		}
@@ -349,6 +351,9 @@ public static function computeCheckSum(string $content): string {
 	 * @throws Exception
 	 */
 	public function autosave(Document $document, IContext $context, int $version, string $autoSaveDocument, string $documentState, bool $force = false, bool $manualSave = false): Document {
+		if ($document->id === null) {
+			throw new RuntimeException('Document needs an id to autosave');
+		}
 		if ($context->isReadOnly()) {
 			throw new NotPermittedException('Read-only permission cannot save document changes. Please reload the page.');
 		}
@@ -437,13 +442,15 @@ public function resetDocument(string $contextType, int $contextId, bool $force =
 		$contextString = $contextType . '(' . $contextId . ')';
 
 		$document = $this->documentMapper->load($contextType, $contextId);
-		if (!$document) {
+		if (!$document || $document->id === null) {
 			// no document found for the file in question - so nothing to reset.
 			$this->logger->info('did not find document - document not reset.' . $contextString);
 			return;
 		}
 
-		if (!$force && $this->hasUnsavedChanges($document)) {
+		$stepsVersion = $this->stepMapper->getLatestVersion($document->id) ?: 0;
+		$docVersion = $document->getLastSavedVersion();
+		if (!$force && $stepsVersion !== $docVersion) {
 			$this->logger->debug('Did not reset document with unsaved changes for ' . $contextString);
 			throw new DocumentHasUnsavedChangesException('Did not reset document, as it has unsaved changes');
 		}
@@ -469,12 +476,6 @@ public function getAllWithNoActiveSession(): \Generator {
 		return $this->documentMapper->findAllWithNoActiveSessions();
 	}
 
-	public function hasUnsavedChanges(Document $document): bool {
-		$stepsVersion = $this->stepMapper->getLatestVersion($document->getId()) ?: 0;
-		$docVersion = $document->getLastSavedVersion();
-		return $stepsVersion !== $docVersion;
-	}
-
 	private function ensureDocumentsFolder(): bool {
 		try {
 			$this->appData->getFolder('documents');
diff --git a/lib/Service/SessionService.php b/lib/Service/SessionService.php
index 6cf2f872ff9..6ebbb984f74 100644
--- a/lib/Service/SessionService.php
+++ b/lib/Service/SessionService.php
@@ -54,7 +54,7 @@ public function __construct(
 		$this->cache = $cacheFactory->createDistributed('text_sessions');
 	}
 
-	public function initSession(int $documentId, ?string $guestName = null): Session {
+	public function initSession(string $documentId, ?string $guestName = null): Session {
 		$session = new Session();
 		$session->setDocumentId($documentId);
 		$session->setUserId($this->userId);
@@ -71,7 +71,7 @@ public function initSession(int $documentId, ?string $guestName = null): Session
 		return $session;
 	}
 
-	public function closeSession(int $documentId, int $sessionId, string $token): void {
+	public function closeSession(string $documentId, int $sessionId, string $token): void {
 		try {
 			$session = $this->sessionMapper->find($documentId, $sessionId, $token);
 			$this->cache->remove($token);
@@ -80,7 +80,7 @@ public function closeSession(int $documentId, int $sessionId, string $token): vo
 		}
 	}
 
-	public function getAllSessions(int $documentId): array {
+	public function getAllSessions(string $documentId): array {
 		$sessions = $this->sessionMapper->findAll($documentId);
 		return array_map(function (Session $session) {
 			$result = $session->jsonSerialize();
@@ -92,11 +92,11 @@ public function getAllSessions(int $documentId): array {
 		}, $sessions);
 	}
 
-	public function countAllSessions(int $documentId): int {
+	public function countAllSessions(string $documentId): int {
 		return $this->sessionMapper->countAll($documentId);
 	}
 
-	public function getActiveSessions(int $documentId): array {
+	public function getActiveSessions(string $documentId): array {
 		$sessions = $this->sessionMapper->findAllActive($documentId);
 		return array_map(function (Session $session) {
 			$result = $session->jsonSerialize();
@@ -122,7 +122,7 @@ public function findAllInactive(): array {
 		return $this->sessionMapper->findAllInactive();
 	}
 
-	public function removeInactiveSessionsWithoutSteps(?int $documentId = null): int {
+	public function removeInactiveSessionsWithoutSteps(?string $documentId = null): int {
 		// No need to clear the cache here as we already set a TTL
 		return $this->sessionMapper->deleteInactiveWithoutSteps($documentId);
 	}
@@ -135,7 +135,7 @@ public function removeOrphanedSteps(int $ageInSeconds = 604800): int {
 		return $this->sessionMapper->deleteOrphanedSteps($ageInSeconds);
 	}
 
-	public function getSession(int $documentId, int $sessionId, string $token): ?Session {
+	public function getSession(string $documentId, int $sessionId, string $token): ?Session {
 		if ($this->session !== null) {
 			return $this->session;
 		}
@@ -162,7 +162,7 @@ public function getSession(int $documentId, int $sessionId, string $token): ?Ses
 		return $this->session;
 	}
 
-	public function getValidSession(int $documentId, int $sessionId, string $token): ?Session {
+	public function getValidSession(string $documentId, int $sessionId, string $token): ?Session {
 		$session = $this->getSession($documentId, $sessionId, $token);
 		if ($session === null) {
 			return null;
@@ -241,7 +241,7 @@ private function generateRandomString(int $length = 64): string {
 		return $randomizer->getBytesFromString(ISecureRandom::CHAR_ALPHANUMERIC . '+/', $length);
 	}
 
-	public function isUserInDocument(int $documentId, string $mention): bool {
+	public function isUserInDocument(string $documentId, string $mention): bool {
 		return $this->sessionMapper->isUserInDocument($documentId, $mention);
 	}
 }
diff --git a/src/EditorFactory.ts b/src/EditorFactory.ts
index ab262591459..bfe5e119faf 100644
--- a/src/EditorFactory.ts
+++ b/src/EditorFactory.ts
@@ -5,7 +5,7 @@
 
 import type { Extension } from '@tiptap/core'
 import type { Node } from '@tiptap/pm/model'
-import type { Connection } from './composables/useConnection.ts'
+import type { Connection } from './types/Connection.ts'
 
 import { Editor } from '@tiptap/core'
 import hljs from 'highlight.js/lib/core'
diff --git a/src/apis/attach.ts b/src/apis/attach.ts
index 9dcbab90903..1ecbf20a010 100644
--- a/src/apis/attach.ts
+++ b/src/apis/attach.ts
@@ -4,7 +4,7 @@
  */
 
 import type { ShallowRef } from 'vue'
-import type { Connection } from '../composables/useConnection.ts'
+import type { Connection } from '../types/Connection.ts'
 
 import axios from '@nextcloud/axios'
 import { generateUrl } from '@nextcloud/router'
diff --git a/src/apis/connect.ts b/src/apis/connect.ts
index 9d21985c525..3b1a306f9fb 100644
--- a/src/apis/connect.ts
+++ b/src/apis/connect.ts
@@ -3,8 +3,9 @@
  * SPDX-License-Identifier: AGPL-3.0-or-later
  */
 
-import type { Connection } from '../composables/useConnection.ts'
-import type { Document, GuestSession, Session } from '../services/SyncService.ts'
+import type { Connection } from '../types/Connection.ts'
+import type { Document } from '../types/Document.ts'
+import type { GuestSession, Session } from '../types/Session.ts'
 
 import axios from '@nextcloud/axios'
 import { generateUrl } from '@nextcloud/router'
diff --git a/src/apis/mention.ts b/src/apis/mention.ts
index de562b9c469..a742a5fd5e3 100644
--- a/src/apis/mention.ts
+++ b/src/apis/mention.ts
@@ -4,7 +4,7 @@
  */
 
 import type { ShallowRef } from 'vue'
-import type { Connection } from '../composables/useConnection.ts'
+import type { Connection } from '../types/Connection.ts'
 
 import axios from '@nextcloud/axios'
 import { generateUrl } from '@nextcloud/router'
diff --git a/src/apis/save.ts b/src/apis/save.ts
index 554861736b3..fcdcf78d126 100644
--- a/src/apis/save.ts
+++ b/src/apis/save.ts
@@ -4,8 +4,8 @@
  */
 
 import type { ShallowRef } from 'vue'
-import type { Connection } from '../composables/useConnection.ts'
-import type { Document } from '../services/SyncService.ts'
+import type { Connection } from '../types/Connection.ts'
+import type { Document } from '../types/Document.ts'
 
 import { getRequestToken } from '@nextcloud/auth'
 import axios from '@nextcloud/axios'
diff --git a/src/apis/sync.ts b/src/apis/sync.ts
index 13bbedc0c5a..d17410ed3e3 100644
--- a/src/apis/sync.ts
+++ b/src/apis/sync.ts
@@ -4,8 +4,10 @@
  */
 
 import type { ShallowRef } from 'vue'
-import type { Connection } from '../composables/useConnection.ts'
-import type { Document, Session, Step } from '../services/SyncService.ts'
+import type { Connection } from '../types/Connection.ts'
+import type { Document } from '../types/Document.ts'
+import type { Session } from '../types/Session.ts'
+import type { Step } from '../types/Step.ts'
 
 import axios from '@nextcloud/axios'
 import { generateUrl } from '@nextcloud/router'
diff --git a/src/components/CollaborativeEditor.vue b/src/components/CollaborativeEditor.vue
index da54b53e49a..51334d566b1 100644
--- a/src/components/CollaborativeEditor.vue
+++ b/src/components/CollaborativeEditor.vue
@@ -115,8 +115,9 @@ import { CollaborationCaret } from '../extensions/index.js'
 import { exposeForDebugging, removeFromDebugging } from '../helpers/debug.ts'
 import { logger } from '../helpers/logger.ts'
 import { setInitialYjsState } from '../helpers/setInitialYjsState.ts'
-import { ERROR_TYPE, IDLE_TIMEOUT } from '../services/SyncService.ts'
+import { IDLE_TIMEOUT } from '../services/SyncService.ts'
 import { fetchNode } from '../services/WebdavClient.ts'
+import { ERROR_TYPE } from '../types/ErrorType.ts'
 import {
 	createPlainEditor,
 	createRichEditor,
diff --git a/src/components/Editor/DocumentStatus/SyncStatus.vue b/src/components/Editor/DocumentStatus/SyncStatus.vue
index 7feaa069c82..083a6fc37ec 100644
--- a/src/components/Editor/DocumentStatus/SyncStatus.vue
+++ b/src/components/Editor/DocumentStatus/SyncStatus.vue
@@ -24,7 +24,7 @@
 import { t } from '@nextcloud/l10n'
 import NcButton from '@nextcloud/vue/components/NcButton'
 import NcNoteCard from '@nextcloud/vue/components/NcNoteCard'
-import { ERROR_TYPE } from '../../../services/SyncService.ts'
+import { ERROR_TYPE } from '../../../types/ErrorType.ts'
 
 export default {
 	name: 'SyncStatus',
diff --git a/src/components/Editor/SessionStatus.vue b/src/components/Editor/SessionStatus.vue
index 82fcbf242cb..15869675f67 100644
--- a/src/components/Editor/SessionStatus.vue
+++ b/src/components/Editor/SessionStatus.vue
@@ -41,7 +41,7 @@ import OfflineState from './OfflineState.vue'
 import { useNetworkState } from '../../composables/useNetworkState.ts'
 import { useSaveService } from '../../composables/useSaveService.ts'
 import refreshMoment from '../../mixins/refreshMoment.js'
-import { ERROR_TYPE } from '../../services/SyncService.ts'
+import { ERROR_TYPE } from '../../types/ErrorType.ts'
 import { useIsMobileMixin } from '../Editor.provider.ts'
 
 export default {
diff --git a/src/composables/useConnection.ts b/src/composables/useConnection.ts
index 925d2526a1e..81223ea8383 100644
--- a/src/composables/useConnection.ts
+++ b/src/composables/useConnection.ts
@@ -5,25 +5,14 @@
 
 import type { InjectionKey, ShallowRef } from 'vue'
 import type { OpenData } from '../apis/connect.ts'
-import type { Document, Session } from '../services/SyncService.ts'
+import type { Connection } from '../types/Connection.ts'
+import type { Context } from '../types/Context.ts'
+import type { Document } from '../types/Document.ts'
+import type { Session } from '../types/Session.ts'
 
 import { inject, provide, shallowRef } from 'vue'
 import * as api from '../apis/connect.ts'
 
-export interface Context {
-	type: string
-	id: number
-}
-
-export interface Connection {
-	documentId: number
-	sessionId: number
-	sessionToken: string
-	baseVersionEtag: string
-	filePath: string
-	shareToken?: string
-}
-
 export interface InitialData {
 	document: Document
 	session: Session & { token: string }
diff --git a/src/composables/useEditorMethods.ts b/src/composables/useEditorMethods.ts
index 7dfab0f7f7a..7cab77144d5 100644
--- a/src/composables/useEditorMethods.ts
+++ b/src/composables/useEditorMethods.ts
@@ -5,13 +5,18 @@
 
 import type { Editor } from '@tiptap/core'
 import type { AwarenessUser } from '../extensions/CollaborationCaret.ts'
-import type { Session } from '../services/SyncService.ts'
+import type { Session } from '../types/Session.ts'
 
 import escapeHtml from 'escape-html'
 import Markdown from '../extensions/Markdown.js'
 import markdownit from '../markdownit/index.js'
 import { isUser } from '../services/SyncService.ts'
 
+/**
+ *
+ * @param content
+ * @param markdown
+ */
 export function renderEditorContent(content: string, markdown: boolean) {
 	return markdown
 		? markdownit.render(content) + '<p/>'
diff --git a/src/composables/useFileProps.ts b/src/composables/useFileProps.ts
index e6647a5528f..7f729742f47 100644
--- a/src/composables/useFileProps.ts
+++ b/src/composables/useFileProps.ts
@@ -4,7 +4,7 @@
  */
 
 import type { InjectionKey } from 'vue'
-import type { Context } from './useConnection.ts'
+import type { Context } from '../types/Context.ts'
 
 import { inject, provide } from 'vue'
 
diff --git a/src/composables/useIndexedDbProvider.ts b/src/composables/useIndexedDbProvider.ts
index 81dbc046e32..e178192f396 100644
--- a/src/composables/useIndexedDbProvider.ts
+++ b/src/composables/useIndexedDbProvider.ts
@@ -4,7 +4,7 @@
  */
 
 import type { Doc } from 'yjs'
-import type { Context } from './useConnection.ts'
+import type { Context } from '../types/Context.ts'
 
 import { readonly, ref } from 'vue'
 import { IndexeddbPersistence } from 'y-indexeddb'
diff --git a/src/composables/useSaveService.ts b/src/composables/useSaveService.ts
index 7d1b3bfa9d0..a2b02b8eb80 100644
--- a/src/composables/useSaveService.ts
+++ b/src/composables/useSaveService.ts
@@ -6,8 +6,9 @@
 import type { InjectionKey, ShallowRef } from 'vue'
 import type { Doc } from 'yjs'
 import type { SaveData } from '../apis/save.ts'
-import type { Document, SyncService } from '../services/SyncService.ts'
-import type { Connection } from './useConnection.ts'
+import type { SyncService } from '../services/SyncService.ts'
+import type { Connection } from '../types/Connection.ts'
+import type { Document } from '../types/Document.ts'
 
 import { computed, inject, onUnmounted, provide, ref, watch } from 'vue'
 import { getDocumentState } from '../helpers/yjs.ts'
diff --git a/src/composables/useSessions.ts b/src/composables/useSessions.ts
index 3ea68e85e06..1db4f8035b2 100644
--- a/src/composables/useSessions.ts
+++ b/src/composables/useSessions.ts
@@ -6,7 +6,7 @@
 import type { ShallowRef } from 'vue'
 import type { OpenData } from '../apis/connect.ts'
 import type { SyncService } from '../services/SyncService.ts'
-import type { Session } from '../services/SyncService.ts'
+import type { Session } from '../types/Session.ts'
 
 import {
 	computed,
diff --git a/src/composables/useSyncService.ts b/src/composables/useSyncService.ts
index 3a612f08c46..1743f1cdbb1 100644
--- a/src/composables/useSyncService.ts
+++ b/src/composables/useSyncService.ts
@@ -4,7 +4,8 @@
  */
 
 import type { InjectionKey, ShallowRef } from 'vue'
-import type { Connection, InitialData } from './useConnection.ts'
+import type { Connection } from '../types/Connection.ts'
+import type { InitialData } from './useConnection.ts'
 
 import { inject, provide } from 'vue'
 import { SyncService } from '../services/SyncService.ts'
diff --git a/src/createEditor.ts b/src/createEditor.ts
index c48db34373d..d966b07d6a3 100644
--- a/src/createEditor.ts
+++ b/src/createEditor.ts
@@ -5,8 +5,8 @@
 
 import type { EventHandler } from '@nextcloud/event-bus'
 import type { App } from 'vue'
-import type { Context } from './composables/useConnection.ts'
 import type { TextEditorEmbed } from './TextEditorEmbed.ts'
+import type { Context } from './types/Context.ts'
 
 import { createApp, reactive, shallowRef } from 'vue'
 import {
diff --git a/src/extensions/Autofocus.ts b/src/extensions/Autofocus.ts
index 15dbdb30cdc..1ccb88c6525 100644
--- a/src/extensions/Autofocus.ts
+++ b/src/extensions/Autofocus.ts
@@ -3,7 +3,7 @@
  * SPDX-License-Identifier: AGPL-3.0-or-later
  */
 
-import type { Context } from '../composables/useConnection.ts'
+import type { Context } from '../types/Context.ts'
 
 import { Extension } from '@tiptap/core'
 
diff --git a/src/extensions/RichText.ts b/src/extensions/RichText.ts
index e1162e122ad..ce8dd5b37ba 100644
--- a/src/extensions/RichText.ts
+++ b/src/extensions/RichText.ts
@@ -3,7 +3,7 @@
  * SPDX-License-Identifier: AGPL-3.0-or-later
  */
 import type { AnyExtension, Extensions } from '@tiptap/core'
-import type { Connection } from '../composables/useConnection.ts'
+import type { Connection } from '../types/Connection.ts'
 
 import { t } from '@nextcloud/l10n'
 import { Extension } from '@tiptap/core'
diff --git a/src/helpers/steps.ts b/src/helpers/steps.ts
index 12c1a6bf3e0..7f563571533 100644
--- a/src/helpers/steps.ts
+++ b/src/helpers/steps.ts
@@ -3,7 +3,8 @@
  * SPDX-License-Identifier: AGPL-3.0-or-later
  */
 
-import type { Session, Step } from '../services/SyncService.ts'
+import type { Session } from '../types/Session.ts'
+import type { Step } from '../types/Step.ts'
 
 import { COLLABORATOR_DISCONNECT_TIME } from '../services/SyncService.ts'
 
diff --git a/src/helpers/yjs.ts b/src/helpers/yjs.ts
index a6d926aaf96..a084d8c506f 100644
--- a/src/helpers/yjs.ts
+++ b/src/helpers/yjs.ts
@@ -4,7 +4,7 @@
  */
 
 import type { OpenData } from '../apis/connect.ts'
-import type { Step } from '../services/SyncService.ts'
+import type { Step } from '../types/Step.ts'
 
 import * as decoding from 'lib0/decoding.js'
 import * as encoding from 'lib0/encoding.js'
diff --git a/src/services/AttachmentResolver.js b/src/services/AttachmentResolver.js
index bc915c98156..3028dd55308 100644
--- a/src/services/AttachmentResolver.js
+++ b/src/services/AttachmentResolver.js
@@ -12,7 +12,7 @@ export default class AttachmentResolver {
 	#user
 	#shareToken
 	#currentDirectory
-	#documentId
+	#fileId
 	#initAttachmentListPromise
 	#attachmentList = []
 
@@ -21,15 +21,16 @@ export default class AttachmentResolver {
 		this.#user = user
 		this.#shareToken = shareToken
 		this.#currentDirectory = currentDirectory
-		this.#documentId = fileId ?? session.documentId
+		this.#fileId = fileId
 	}
 
 	async #updateAttachmentList() {
 		const response = await axios.post(generateUrl('/apps/text/attachments'), {
-			documentId: this.#session?.documentId ?? this.#documentId,
+			documentId: this.#session?.documentId,
 			sessionId: this.#session?.id,
 			sessionToken: this.#session?.token,
 			shareToken: this.#shareToken,
+			fileId: this.#fileId,
 		})
 		this.#attachmentList = response.data
 	}
diff --git a/src/services/NotifyService.ts b/src/services/NotifyService.ts
index 6fac7fe263d..03e2280f5ac 100644
--- a/src/services/NotifyService.ts
+++ b/src/services/NotifyService.ts
@@ -12,7 +12,7 @@ import mitt from 'mitt'
 export declare type EventTypes = {
 	notify_push: {
 		messageType: unknown
-		messageBody: { steps: string[], documentId: number }
+		messageBody: { steps: string[], documentId: string }
 	}
 }
 
@@ -29,7 +29,7 @@ if (!window._nc_text_notify) {
 				'text_steps',
 				(
 					messageType: string,
-					messageBody: { steps: string[], documentId: number },
+					messageBody: { steps: string[], documentId: string },
 				) => {
 					window._nc_text_notify?.emit('notify_push', {
 						messageType,
diff --git a/src/services/PollingBackend.ts b/src/services/PollingBackend.ts
index ff6fe94e826..271bc145681 100644
--- a/src/services/PollingBackend.ts
+++ b/src/services/PollingBackend.ts
@@ -4,14 +4,17 @@
  */
 import type { Emitter } from 'mitt'
 import type { OpenData } from '../apis/connect.ts'
-import type { Connection } from '../composables/useConnection.ts'
+import type { Connection } from '../types/Connection.ts'
+import type { Document } from '../types/Document.ts'
+import type { Session } from '../types/Session.ts'
+import type { Step } from '../types/Step.ts'
 import type { EventTypes } from './NotifyService.ts'
-import type { Document, Session, Step, SyncService } from './SyncService.js'
+import type { SyncService } from './SyncService.js'
 
 import { sync } from '../apis/sync.ts'
 import { logger } from '../helpers/logger.js'
+import { ERROR_TYPE } from '../types/ErrorType.ts'
 import getNotifyBus from './NotifyService.ts'
-import { ERROR_TYPE } from './SyncService.js'
 
 /**
  * Minimum inverval to refetch the document changes in ms.
diff --git a/src/services/SaveService.ts b/src/services/SaveService.ts
index 0992ea12d71..fb070c69197 100644
--- a/src/services/SaveService.ts
+++ b/src/services/SaveService.ts
@@ -5,15 +5,15 @@
 
 import type { Ref, ShallowRef } from 'vue'
 import type { SaveData } from '../apis/save.ts'
-import type { Connection } from '../composables/useConnection.ts'
-import type { Document } from './SyncService.ts'
+import type { Connection } from '../types/Connection.ts'
+import type { Document } from '../types/Document.ts'
 
 import { showError } from '@nextcloud/dialogs'
 import debounce from 'debounce'
 import mitt from 'mitt'
 import { save, saveViaSendBeacon } from '../apis/save.ts'
 import { logger } from '../helpers/logger.js'
-import { ERROR_TYPE } from './SyncService.ts'
+import { ERROR_TYPE } from '../types/ErrorType.ts'
 
 // Time constants in seconds:
 // Only autosave after 1 second typing breaks
diff --git a/src/services/SyncService.ts b/src/services/SyncService.ts
index 4f91c318c39..ffe95c8d07d 100644
--- a/src/services/SyncService.ts
+++ b/src/services/SyncService.ts
@@ -5,7 +5,11 @@
 
 import type { ShallowRef } from 'vue'
 import type { OpenData } from '../apis/connect.ts'
-import type { Connection } from '../composables/useConnection.ts'
+import type { Connection } from '../types/Connection.ts'
+import type { Document } from '../types/Document.ts'
+import type { ErrorType } from '../types/ErrorType.ts'
+import type { GuestSession, Session, UserSession } from '../types/Session.ts'
+import type { Step } from '../types/Step.ts'
 
 import mitt from 'mitt'
 import { close } from '../apis/connect.ts'
@@ -13,6 +17,7 @@ import { push } from '../apis/sync.ts'
 import { logger } from '../helpers/logger.js'
 import { awarenessSteps } from '../helpers/steps.ts'
 import { documentStateToStep } from '../helpers/yjs.ts'
+import { ERROR_TYPE } from '../types/ErrorType.ts'
 import Outbox from './Outbox.ts'
 import PollingBackend from './PollingBackend.ts'
 
@@ -27,58 +32,6 @@ const COLLABORATOR_IDLE_TIME = 60
 
 const COLLABORATOR_DISCONNECT_TIME = 90
 
-const ERROR_TYPE = {
-	/**
-	 * Failed to save collaborative document due to external change
-	 * collision needs to be resolved manually
-	 */
-	SAVE_COLLISION: 0,
-	/**
-	 * Failed to push changes for MAX_REBASE_RETRY times
-	 */
-	PUSH_FAILURE: 1,
-
-	LOAD_ERROR: 2,
-
-	CONNECTION_FAILED: 3,
-
-	SOURCE_NOT_FOUND: 4,
-
-	PUSH_FORBIDDEN: 5,
-} as const
-
-type ErrorType = (typeof ERROR_TYPE)[keyof typeof ERROR_TYPE]
-
-/*
- * Step as what we expect to be returned from the server right now.
- */
-export interface Step {
-	data: string[]
-	version: number
-	sessionId: number
-}
-
-export interface UserSession {
-	id: number
-	userId: string
-	color: string
-	lastAwarenessMessage: string
-	lastContact: number
-	documentId: number
-	displayName: string
-}
-
-export interface GuestSession {
-	id: number
-	color: string
-	lastAwarenessMessage: string
-	lastContact: number
-	guestName: string
-	documentId: number
-}
-
-export type Session = UserSession | GuestSession
-
 /**
  * Test if a session is a guest session
  *
@@ -97,14 +50,6 @@ export function isUser(session: Session): session is UserSession {
 	return 'userId' in session && typeof session.userId === 'string'
 }
 
-export interface Document {
-	id: number
-	lastSavedVersion: number
-	lastSavedVersionTime: number
-	baseVersionEtag: string
-	initialVersion: number
-}
-
 export declare type EventTypes = {
 	/* Document state */
 	opened: OpenData
diff --git a/src/services/WebSocketPolyfill.ts b/src/services/WebSocketPolyfill.ts
index 1dcd3f90af7..bd217ac63f3 100644
--- a/src/services/WebSocketPolyfill.ts
+++ b/src/services/WebSocketPolyfill.ts
@@ -4,7 +4,8 @@
  */
 
 import type { OpenData } from '../apis/connect.ts'
-import type { Step, SyncService } from './SyncService.ts'
+import type { Step } from '../types/Step.ts'
+import type { SyncService } from './SyncService.ts'
 
 import { decodeArrayBuffer, encodeArrayBuffer } from '../helpers/base64.ts'
 import { logger } from '../helpers/logger.js'
@@ -38,7 +39,7 @@ export default function initWebSocketPolyfill(syncService: SyncService) {
 		#onSync
 		#onOpened
 		#processingVersion = 0
-		#documentId = 0
+		#documentId: string | undefined
 
 		constructor(url: string) {
 			this.#notifyPushBus = getNotifyBus()
@@ -130,7 +131,7 @@ export default function initWebSocketPolyfill(syncService: SyncService) {
 		#onNotifyPush({
 			messageBody,
 		}: {
-			messageBody: { documentId: number, steps: string[] }
+			messageBody: { documentId: string, steps: string[] }
 		}) {
 			debug('WebSocketPolyfill#onNotifyPush', messageBody)
 			if (messageBody.documentId !== this.#documentId) {
diff --git a/src/tests/helpers/updateFromContent.spec.ts b/src/tests/helpers/updateFromContent.spec.ts
index a9ed551e850..990b49bcdcc 100644
--- a/src/tests/helpers/updateFromContent.spec.ts
+++ b/src/tests/helpers/updateFromContent.spec.ts
@@ -3,7 +3,7 @@
  * SPDX-License-Identifier: AGPL-3.0-or-later
  */
 
-import type { Connection } from '../../composables/useConnection.js'
+import type { Connection } from '../../types/Connection.ts'
 
 import { Collaboration } from '@tiptap/extension-collaboration'
 import { describe, expect, it } from 'vitest'
@@ -83,7 +83,7 @@ What's that?
  */
 function contentWithUpdates(...updates: Uint8Array[]) {
 	const dummyConnection: Connection = {
-		documentId: 123,
+		documentId: '123',
 		sessionId: 234,
 		sessionToken: 'token',
 		baseVersionEtag: 'etag',
diff --git a/src/tests/services/SyncService.spec.ts b/src/tests/services/SyncService.spec.ts
index c383b16d720..6baac3934f3 100644
--- a/src/tests/services/SyncService.spec.ts
+++ b/src/tests/services/SyncService.spec.ts
@@ -9,7 +9,7 @@ import { provideConnection } from '../../composables/useConnection.js'
 import { SyncService } from '../../services/SyncService.js'
 
 const connection = {
-	documentId: 123,
+	documentId: '123',
 	sessionId: 345,
 	sessionToken: 'sessionToken',
 	filePath: './',
@@ -22,13 +22,13 @@ const initialData = {
 		token: 'shareToken',
 		color: '#abcabc',
 		lastContact: Date.now(),
-		documentId: 123,
+		documentId: '123',
 		displayName: 'My Name',
 		lastAwarenessMessage: 'hi',
 		clientId: 1,
 	},
 	document: {
-		id: 123,
+		id: '123',
 		baseVersionEtag: 'etag',
 		initialVersion: 0,
 		lastSavedVersion: 345,
diff --git a/src/types/Connection.ts b/src/types/Connection.ts
new file mode 100644
index 00000000000..4ea6abef78a
--- /dev/null
+++ b/src/types/Connection.ts
@@ -0,0 +1,13 @@
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+export interface Connection {
+	documentId: string
+	sessionId: number
+	sessionToken: string
+	baseVersionEtag: string
+	filePath: string
+	shareToken?: string
+}
diff --git a/src/types/Context.ts b/src/types/Context.ts
new file mode 100644
index 00000000000..934e41d4e97
--- /dev/null
+++ b/src/types/Context.ts
@@ -0,0 +1,9 @@
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+export interface Context {
+	type: string
+	id: number
+}
diff --git a/src/types/Document.ts b/src/types/Document.ts
new file mode 100644
index 00000000000..d95b6b22779
--- /dev/null
+++ b/src/types/Document.ts
@@ -0,0 +1,12 @@
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+export interface Document {
+	id: string
+	lastSavedVersion: number
+	lastSavedVersionTime: number
+	baseVersionEtag: string
+	initialVersion: number
+}
diff --git a/src/types/ErrorType.ts b/src/types/ErrorType.ts
new file mode 100644
index 00000000000..32b623c5944
--- /dev/null
+++ b/src/types/ErrorType.ts
@@ -0,0 +1,25 @@
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+export const ERROR_TYPE = {
+	/**
+	 * Failed to save collaborative document due to external change
+	 * collision needs to be resolved manually
+	 */
+	SAVE_COLLISION: 0,
+	/**
+	 * Failed to push changes for MAX_REBASE_RETRY times
+	 */
+	PUSH_FAILURE: 1,
+
+	LOAD_ERROR: 2,
+
+	CONNECTION_FAILED: 3,
+
+	SOURCE_NOT_FOUND: 4,
+
+	PUSH_FORBIDDEN: 5,
+} as const
+export type ErrorType = (typeof ERROR_TYPE)[keyof typeof ERROR_TYPE]
diff --git a/src/types/Session.ts b/src/types/Session.ts
new file mode 100644
index 00000000000..6d8cb8d668a
--- /dev/null
+++ b/src/types/Session.ts
@@ -0,0 +1,25 @@
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+export interface UserSession {
+	id: number
+	userId: string
+	color: string
+	lastAwarenessMessage: string
+	lastContact: number
+	documentId: string
+	displayName: string
+}
+
+export interface GuestSession {
+	id: number
+	color: string
+	lastAwarenessMessage: string
+	lastContact: number
+	guestName: string
+	documentId: string
+}
+
+export type Session = UserSession | GuestSession
diff --git a/src/types/Step.ts b/src/types/Step.ts
new file mode 100644
index 00000000000..99c13001f0a
--- /dev/null
+++ b/src/types/Step.ts
@@ -0,0 +1,14 @@
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+/*
+ * Step as what we expect to be returned from the server right now.
+ */
+
+export interface Step {
+	data: string[]
+	version: number
+	sessionId: number
+}
diff --git a/src/views/CollaborativeEditorApp.vue b/src/views/CollaborativeEditorApp.vue
index 6a10582e3e6..c686b2d3f98 100644
--- a/src/views/CollaborativeEditorApp.vue
+++ b/src/views/CollaborativeEditorApp.vue
@@ -24,7 +24,7 @@
 
 <script setup lang='ts'>
 import type { ComponentInstance, ShallowRef } from 'vue'
-import type { Context } from '../composables/useConnection.ts'
+import type { Context } from '../types/Context.ts'
 
 import { useTemplateRef } from 'vue'
 import EditorReloader from '../components/EditorReloader.vue'
diff --git a/tests/unit/Db/SessionMapperTest.php b/tests/unit/Db/SessionMapperTest.php
index b0da154b7a1..452e7b3ac9d 100644
--- a/tests/unit/Db/SessionMapperTest.php
+++ b/tests/unit/Db/SessionMapperTest.php
@@ -145,13 +145,15 @@ public function testDeleteOrphanedSteps() {
 		$eightDaysAgo = time() - (8 * 24 * 60 * 60);
 
 		// Create document
-		$document = $this->documentMapper->insert(Document::fromParams([
+		$document = Document::fromParams([
 			'contextId' => 123,
 			'contextType' => 'file',
 			'currentVersion' => 0,
 			'lastSavedVersion' => 100,
 			'lastSavedVersionTime' => time()
-		]));
+		]);
+		$document->generateId();
+		$document = $this->documentMapper->insert($document);
 
 		// Create Orphaned step without document (delete)
 		$this->stepMapper->insert(Step::fromParams([
@@ -165,7 +167,7 @@ public function testDeleteOrphanedSteps() {
 		$this->stepMapper->insert(Step::fromParams([
 			'id' => 1,
 			'sessionId' => 99999,
-			'documentId' => $document->getId(),
+			'documentId' => $document->id,
 			'data' => 'ORPHANED_OLD_VERSION',
 			'timestamp' => $eightDaysAgo,
 			'version' => 1
@@ -175,7 +177,7 @@ public function testDeleteOrphanedSteps() {
 		$this->stepMapper->insert(Step::fromParams([
 			'id' => 100,
 			'sessionId' => 99999,
-			'documentId' => $document->getId(),
+			'documentId' => $document->id,
 			'data' => 'ORPHANED_CURRENT_VERSION',
 			'version' => 2
 		]));
@@ -184,14 +186,14 @@ public function testDeleteOrphanedSteps() {
 		$this->stepMapper->insert(Step::fromParams([
 			'id' => 101,
 			'sessionId' => 99999,
-			'documentId' => $document->getId(),
+			'documentId' => $document->id,
 			'data' => 'ORPHANED_NEW_VERSION',
 			'timestamp' => $eightDaysAgo,
 			'version' => 3
 		]));
 
 		// Verify steps for document 1 and 99999
-		self::assertCount(3, $this->stepMapper->find(1, 0));
+		self::assertCount(3, $this->stepMapper->find($document->id, 0));
 		self::assertCount(1, $this->stepMapper->find(99999, 0));
 
 		// Delete orphaned steps older than 7 days
diff --git a/tests/unit/Middleware/SessionMiddlewareTest.php b/tests/unit/Middleware/SessionMiddlewareTest.php
index a57a18a08be..36aedc3087e 100644
--- a/tests/unit/Middleware/SessionMiddlewareTest.php
+++ b/tests/unit/Middleware/SessionMiddlewareTest.php
@@ -28,6 +28,7 @@ class SessionMiddlewareTest extends TestCase {
 	private IUserSession $userSession;
 	private IUserManager $userManager;
 	private FileService $fileService;
+	private string $documentId;
 
 	protected function setUp(): void {
 		parent::setUp();
@@ -40,10 +41,11 @@ protected function setUp(): void {
 		$this->fileService = $this->createMock(FileService::class);
 
 		$document = new Document();
-		$document->setId(111);
 		$document->setContextId(999);
 		$document->setContextType('file');
-		$this->documentService->method('getDocument')->with(111)->willReturn($document);
+		$document->generateId();
+		$this->documentId = $document->id;
+		$this->documentService->method('getDocument')->with($document->id)->willReturn($document);
 
 		$this->middleware = new SessionMiddleware(
 			$this->request,
@@ -191,7 +193,7 @@ public function testAfterExceptionMapsAccountDisabledToForbidden(): void {
 
 	private function invokeAssertDocumentSession(ISessionAwareController $controller, ?string $shareToken = null): void {
 		$this->request->method('getParam')->willReturnMap([
-			['documentId', null, 111],
+			['documentId', null, $this->documentId],
 			['sessionId', null, 1],
 			['sessionToken', null, 'sessionToken'],
 			['token', null, $shareToken],
@@ -202,7 +204,7 @@ private function invokeAssertDocumentSession(ISessionAwareController $controller
 
 	private function invokeMiddleware(?string $token, ?string $userName = null, ?ISessionAwareController $controller = null): void {
 		$this->request->method('getParam')->willReturnMap([
-			['documentId', null, 111],
+			['documentId', null, $this->documentId],
 			['shareToken', null, $token],
 		]);
 
diff --git a/tests/unit/Service/ApiServiceTest.php b/tests/unit/Service/ApiServiceTest.php
index e386d0a4424..51b63663f03 100644
--- a/tests/unit/Service/ApiServiceTest.php
+++ b/tests/unit/Service/ApiServiceTest.php
@@ -50,7 +50,7 @@ public function setUp(): void {
 
 	public function testCreateNewSession() {
 		$document = new Document();
-		$document->setId(123);
+		$document->generateId();
 		$context = $this->createMock(IContext::class);
 		$documentData = new DocumentData(document: $document, documentState: 'documentState');
 		$sessionInfo = new SessionInfo(content: 'content', readOnly: false, lock: null, hasOwner: true);
@@ -79,6 +79,7 @@ public function testSaveWithNotPermittedException() {
 		$session->setDocumentId(123);
 
 		$document = new Document();
+		$document->generateId();
 		$user = $this->createStub(IUser::class);
 
 		$this->documentService->method('autosave')->willThrowException(new  \OCP\Files\NotPermittedException());
diff --git a/tests/unit/Service/DocumentServiceTest.php b/tests/unit/Service/DocumentServiceTest.php
index 2c631afaf24..e06b2d0196e 100644
--- a/tests/unit/Service/DocumentServiceTest.php
+++ b/tests/unit/Service/DocumentServiceTest.php
@@ -55,10 +55,10 @@ public function setUp(): void {
 
 	private function createDocument(string $etag, int $mtime, string $content): Document {
 		$document = new Document();
-		$document->setId(123);
 		$document->setLastSavedVersionEtag($etag);
 		$document->setLastSavedVersionTime($mtime);
 		$document->setChecksum(DocumentService::computeCheckSum($content));
+		$document->generateId();
 		return $document;
 	}
 
@@ -66,7 +66,7 @@ public function testNoAutosavingWhileSaveIsUnderWay(): void {
 		$document = $this->createDocument('etag1', 1000, 'new content');
 		$context = $this->createMock(FileContext::class);
 		$this->cache->method('get')
-			->with('document-save-lock-123')
+			->with('document-save-lock-' . $document->id)
 			->willReturn(true);
 		$this->documentMapper->expects(self::never())->method('update');