diff --git a/appinfo/routes.php b/appinfo/routes.php
index 3dc4df1d0..e49b7d1d4 100644
--- a/appinfo/routes.php
+++ b/appinfo/routes.php
@@ -34,6 +34,7 @@
 		['name' => 'assistantApi#shareOutputFile', 'url' => '/api/{apiVersion}/task/{ocpTaskId}/file/{fileId}/share', 'verb' => 'POST', 'requirements' => $requirements],
 		['name' => 'assistantApi#saveOutputFile', 'url' => '/api/{apiVersion}/task/{ocpTaskId}/file/{fileId}/save', 'verb' => 'POST', 'requirements' => $requirements],
 		['name' => 'assistantApi#getOutputFilePreview', 'url' => '/api/{apiVersion}/task/{ocpTaskId}/output-file/{fileId}/preview', 'verb' => 'GET', 'requirements' => $requirements],
+		['name' => 'assistantApi#getOutputFileInfo', 'url' => '/api/{apiVersion}/task/{ocpTaskId}/output-file/{fileId}/info', 'verb' => 'GET', 'requirements' => $requirements],
 		['name' => 'assistantApi#getOutputFile', 'url' => '/api/{apiVersion}/task/{ocpTaskId}/output-file/{fileId}/download', 'verb' => 'GET', 'requirements' => $requirements],
 		['name' => 'assistantApi#runFileAction', 'url' => '/api/{apiVersion}/file-action/{fileId}/{taskTypeId}', 'verb' => 'POST', 'requirements' => $requirements],
 		['name' => 'assistantApi#getAssistantFolderPath', 'url' => '/api/{apiVersion}/assistant-folder-path', 'verb' => 'GET', 'requirements' => $requirements],
diff --git a/lib/Controller/AssistantApiController.php b/lib/Controller/AssistantApiController.php
index d9953d3dd..72f8119b2 100644
--- a/lib/Controller/AssistantApiController.php
+++ b/lib/Controller/AssistantApiController.php
@@ -27,6 +27,7 @@
 use OCP\IL10N;
 use OCP\IRequest;
 use OCP\Lock\LockedException;
+use OCP\TaskProcessing\Exception\NotFoundException as TaskProcessingNotFoundException;
 use OCP\TaskProcessing\Task;
 use OCP\TaskProcessing\TaskTypes\AudioToText;
 use OCP\TaskProcessing\TaskTypes\TextToTextSummary;
@@ -421,6 +422,43 @@ public function getOutputFile(int $ocpTaskId, int $fileId): DataDownloadResponse
 		}
 	}
 
+	/**
+	 * Get task output file info
+	 *
+	 * Get information about a task output file
+	 *
+	 * @param int $ocpTaskId The task ID
+	 * @param int $fileId The task output file ID
+	 * @return DataResponse<Http::STATUS_OK, array{name: string, size: int}, array{}>|DataResponse<Http::STATUS_NOT_FOUND, '', array{}>|DataResponse<Http::STATUS_INTERNAL_SERVER_ERROR, '', array{}>
+	 *
+	 * 200: The file info is returned
+	 * 404: The output file is not found
+	 * 500: The output file info could not be retrieved
+	 */
+	#[NoAdminRequired]
+	#[NoCsrfRequired]
+	public function getOutputFileInfo(int $ocpTaskId, int $fileId): DataResponse {
+		try {
+			$fileInfo = $this->assistantService->getTaskOutputFileInfo($this->userId, $ocpTaskId, $fileId);
+			if ($fileInfo !== null) {
+				return new DataResponse($fileInfo);
+			}
+			return new DataResponse('', Http::STATUS_NOT_FOUND);
+		} catch (Exception $e) {
+			// Unauthorized and not found both map to 404 so the response does
+			// not reveal whether another user's task exists.
+			if (in_array($e->getCode(), [Http::STATUS_UNAUTHORIZED, Http::STATUS_NOT_FOUND], true)) {
+				return new DataResponse('', Http::STATUS_NOT_FOUND);
+			}
+			$this->logger->error('getOutputFileInfo error', ['exception' => $e]);
+		} catch (TaskProcessingNotFoundException $e) {
+			return new DataResponse('', Http::STATUS_NOT_FOUND);
+		} catch (Throwable $e) {
+			$this->logger->error('getOutputFileInfo error', ['exception' => $e]);
+		}
+		return new DataResponse('', Http::STATUS_INTERNAL_SERVER_ERROR);
+	}
+
 	/**
 	 * Run a file action
 	 *
diff --git a/lib/Service/AssistantService.php b/lib/Service/AssistantService.php
index 768b9f1ce..7cf65cecc 100644
--- a/lib/Service/AssistantService.php
+++ b/lib/Service/AssistantService.php
@@ -655,6 +655,23 @@ public function getTaskOutputFile(string $userId, int $ocpTaskId, int $fileId):
 		return $node;
 	}
 
+	/**
+	 * @param string $userId
+	 * @param int $ocpTaskId
+	 * @param int $fileId
+	 * @return array|null
+	 * @throws Exception
+	 * @throws NotFoundException
+	 * @throws TaskProcessingException
+	 */
+	public function getTaskOutputFileInfo(string $userId, int $ocpTaskId, int $fileId): ?array {
+		$file = $this->getTaskOutputFile($userId, $ocpTaskId, $fileId);
+		return [
+			'name' => $file->getName(),
+			'size' => $file->getSize(),
+		];
+	}
+
 	/**
 	 * @param string $userId
 	 * @param int $ocpTaskId
diff --git a/openapi.json b/openapi.json
index 1ed2389b1..d3afa4da3 100644
--- a/openapi.json
+++ b/openapi.json
@@ -2452,6 +2452,201 @@
                 }
             }
         },
+        "/ocs/v2.php/apps/assistant/api/{apiVersion}/task/{ocpTaskId}/output-file/{fileId}/info": {
+            "get": {
+                "operationId": "assistant_api-get-output-file-info",
+                "summary": "Get task output file info",
+                "description": "Get information about a task output file",
+                "tags": [
+                    "assistant_api"
+                ],
+                "security": [
+                    {
+                        "bearer_auth": []
+                    },
+                    {
+                        "basic_auth": []
+                    }
+                ],
+                "parameters": [
+                    {
+                        "name": "apiVersion",
+                        "in": "path",
+                        "required": true,
+                        "schema": {
+                            "type": "string",
+                            "enum": [
+                                "v1"
+                            ],
+                            "default": "v1"
+                        }
+                    },
+                    {
+                        "name": "ocpTaskId",
+                        "in": "path",
+                        "description": "The task ID",
+                        "required": true,
+                        "schema": {
+                            "type": "integer",
+                            "format": "int64"
+                        }
+                    },
+                    {
+                        "name": "fileId",
+                        "in": "path",
+                        "description": "The task output file ID",
+                        "required": true,
+                        "schema": {
+                            "type": "integer",
+                            "format": "int64"
+                        }
+                    },
+                    {
+                        "name": "OCS-APIRequest",
+                        "in": "header",
+                        "description": "Required to be true for the API request to pass",
+                        "required": true,
+                        "schema": {
+                            "type": "boolean",
+                            "default": true
+                        }
+                    }
+                ],
+                "responses": {
+                    "200": {
+                        "description": "The file info is returned",
+                        "content": {
+                            "application/json": {
+                                "schema": {
+                                    "type": "object",
+                                    "required": [
+                                        "ocs"
+                                    ],
+                                    "properties": {
+                                        "ocs": {
+                                            "type": "object",
+                                            "required": [
+                                                "meta",
+                                                "data"
+                                            ],
+                                            "properties": {
+                                                "meta": {
+                                                    "$ref": "#/components/schemas/OCSMeta"
+                                                },
+                                                "data": {
+                                                    "type": "object",
+                                                    "required": [
+                                                        "name",
+                                                        "size"
+                                                    ],
+                                                    "properties": {
+                                                        "name": {
+                                                            "type": "string"
+                                                        },
+                                                        "size": {
+                                                            "type": "integer",
+                                                            "format": "int64"
+                                                        }
+                                                    }
+                                                }
+                                            }
+                                        }
+                                    }
+                                }
+                            }
+                        }
+                    },
+                    "404": {
+                        "description": "The output file is not found",
+                        "content": {
+                            "application/json": {
+                                "schema": {
+                                    "type": "object",
+                                    "required": [
+                                        "ocs"
+                                    ],
+                                    "properties": {
+                                        "ocs": {
+                                            "type": "object",
+                                            "required": [
+                                                "meta",
+                                                "data"
+                                            ],
+                                            "properties": {
+                                                "meta": {
+                                                    "$ref": "#/components/schemas/OCSMeta"
+                                                },
+                                                "data": {
+                                                    "type": "string"
+                                                }
+                                            }
+                                        }
+                                    }
+                                }
+                            }
+                        }
+                    },
+                    "500": {
+                        "description": "The output file info could not be retrieved",
+                        "content": {
+                            "application/json": {
+                                "schema": {
+                                    "type": "object",
+                                    "required": [
+                                        "ocs"
+                                    ],
+                                    "properties": {
+                                        "ocs": {
+                                            "type": "object",
+                                            "required": [
+                                                "meta",
+                                                "data"
+                                            ],
+                                            "properties": {
+                                                "meta": {
+                                                    "$ref": "#/components/schemas/OCSMeta"
+                                                },
+                                                "data": {
+                                                    "type": "string"
+                                                }
+                                            }
+                                        }
+                                    }
+                                }
+                            }
+                        }
+                    },
+                    "401": {
+                        "description": "Current user is not logged in",
+                        "content": {
+                            "application/json": {
+                                "schema": {
+                                    "type": "object",
+                                    "required": [
+                                        "ocs"
+                                    ],
+                                    "properties": {
+                                        "ocs": {
+                                            "type": "object",
+                                            "required": [
+                                                "meta",
+                                                "data"
+                                            ],
+                                            "properties": {
+                                                "meta": {
+                                                    "$ref": "#/components/schemas/OCSMeta"
+                                                },
+                                                "data": {}
+                                            }
+                                        }
+                                    }
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+        },
         "/ocs/v2.php/apps/assistant/api/{apiVersion}/task/{ocpTaskId}/output-file/{fileId}/download": {
             "get": {
                 "operationId": "assistant_api-get-output-file",
diff --git a/src/components/TaskListItem.vue b/src/components/TaskListItem.vue
index 59091eb46..5db9b6f04 100644
--- a/src/components/TaskListItem.vue
+++ b/src/components/TaskListItem.vue
@@ -178,7 +178,8 @@ export default {
 		subName() {
 			if (this.task.status === TASK_STATUS_STRING.successful) {
 				if (this.isText2Image) {
-					const nbGeneratedImages = this.task.output?.length ?? 0
+					// text2image output is {images: [fileId, ...]}, not a bare array
+					const nbGeneratedImages = this.task.output?.images?.length ?? 0
 					return n('assistant', '{n} image generated', '{n} images generated', nbGeneratedImages, { n: nbGeneratedImages })
 				}
 				return this.textOutputPreview
diff --git a/src/components/fields/FileDisplay.vue b/src/components/fields/FileDisplay.vue
index 31c5ee26c..d6cb35a5f 100644
--- a/src/components/fields/FileDisplay.vue
+++ b/src/components/fields/FileDisplay.vue
@@ -81,6 +81,8 @@ export default {
 		console.debug('CURRENT TASK', this.myCurrentTaskId)
 		if (!this.isOutput) {
 			this.getFileInfo()
+		} else if (this.myCurrentTaskId !== null && this.myCurrentTaskId !== undefined) {
+			this.getOutputFileInfo()
 		}
 	},
 
@@ -92,6 +94,26 @@ export default {
 					this.fileInfo = response.data.ocs.data
 				})
 		},
+		/**
+		 * Fetch the output file info through the task-scoped endpoint.
+		 * Retries once so a transient failure does not leave the chip
+		 * unnamed for the component's lifetime.
+		 */
+		getOutputFileInfo(retry = true) {
+			const url = generateOcsUrl('apps/assistant/api/v1/task/{taskId}/output-file/{fileId}/info', {
+				taskId: this.myCurrentTaskId,
+				fileId: this.fileId,
+			})
+			axios.get(url)
+				.then((response) => {
+					this.fileInfo = response.data.ocs.data
+				})
+				.catch(() => {
+					if (retry) {
+						this.getOutputFileInfo(false)
+					}
+				})
+		},
 	},
 }
 </script>
diff --git a/src/components/fields/ImageDisplay.vue b/src/components/fields/ImageDisplay.vue
index 7d51b5cbb..dead4d8e6 100644
--- a/src/components/fields/ImageDisplay.vue
+++ b/src/components/fields/ImageDisplay.vue
@@ -3,15 +3,22 @@
   - SPDX-License-Identifier: AGPL-3.0-or-later
 -->
 <template>
-	<div class="image-display">
+	<div class="image-display"
+		:class="{ 'with-name': showName && fileName }">
 		<img :src="imageUrl"
 			:style="style"
 			:class="{ clickable }">
+		<span v-if="showName && fileName"
+			class="image-name"
+			:title="fileName">
+			{{ fileName }}
+		</span>
 	</div>
 </template>
 
 <script>
 import { generateOcsUrl } from '@nextcloud/router'
+import axios from '@nextcloud/axios'
 
 export default {
 	name: 'ImageDisplay',
@@ -44,12 +51,17 @@ export default {
 			type: Boolean,
 			default: false,
 		},
+		showName: {
+			type: Boolean,
+			default: false,
+		},
 	},
 
 	emits: [],
 
 	data() {
 		return {
+			fileInfo: {},
 		}
 	},
 
@@ -57,6 +69,9 @@ export default {
 		myCurrentTaskId() {
 			return this.taskId ?? this.providedCurrentTaskId()
 		},
+		fileName() {
+			return this.fileInfo?.name
+		},
 		imageUrl() {
 			return this.isOutput
 				? generateOcsUrl('apps/assistant/api/v1/task/{taskId}/output-file/{fileId}/preview?x=300&y=300', {
@@ -77,9 +92,41 @@ export default {
 
 	mounted() {
 		console.debug('CURRENT TASK', this.myCurrentTaskId)
+		if (this.showName && this.isOutput && this.myCurrentTaskId !== null && this.myCurrentTaskId !== undefined) {
+			this.getOutputFileInfo()
+		} else if (this.showName && !this.isOutput) {
+			this.getFileInfo()
+		}
 	},
 
 	methods: {
+		getFileInfo() {
+			const url = generateOcsUrl('apps/assistant/api/v1/file/{fileId}/info', { fileId: this.fileId })
+			axios.get(url)
+				.then((response) => {
+					this.fileInfo = response.data.ocs.data
+				})
+		},
+		/**
+		 * Fetch the output file info through the task-scoped endpoint.
+		 * Retries once so a transient failure does not leave the caption
+		 * missing for the component's lifetime.
+		 */
+		getOutputFileInfo(retry = true) {
+			const url = generateOcsUrl('apps/assistant/api/v1/task/{taskId}/output-file/{fileId}/info', {
+				taskId: this.myCurrentTaskId,
+				fileId: this.fileId,
+			})
+			axios.get(url)
+				.then((response) => {
+					this.fileInfo = response.data.ocs.data
+				})
+				.catch(() => {
+					if (retry) {
+						this.getOutputFileInfo(false)
+					}
+				})
+		},
 	},
 }
 </script>
@@ -98,5 +145,15 @@ export default {
 			cursor: pointer !important;
 		}
 	}
+	.image-name {
+		max-width: 200px;
+		overflow: hidden;
+		text-overflow: ellipsis;
+		white-space: nowrap;
+	}
+	&.with-name {
+		flex-direction: column;
+		align-items: center;
+	}
 }
 </style>
diff --git a/src/components/fields/ListOfMediaField.vue b/src/components/fields/ListOfMediaField.vue
index 860aa6a15..2dc384872 100644
--- a/src/components/fields/ListOfMediaField.vue
+++ b/src/components/fields/ListOfMediaField.vue
@@ -61,6 +61,7 @@
 				<component :is="displayComponent"
 					:file-id="fileId"
 					:task-id="providedCurrentTaskId()"
+					:show-name="true"
 					:is-output="isOutput"
 					:clickable="isOutput"
 					@delete="onDelete(fileId)"
diff --git a/src/components/fields/MediaField.vue b/src/components/fields/MediaField.vue
index 03b87ca80..78bb0ecdd 100644
--- a/src/components/fields/MediaField.vue
+++ b/src/components/fields/MediaField.vue
@@ -56,6 +56,7 @@
 				:file-id="value"
 				:task-id="providedCurrentTaskId()"
 				:show-delete="false"
+				:show-name="true"
 				:is-output="isOutput"
 				:clickable="true"
 				@click="onPreviewClick" />
diff --git a/tests/unit/AppInfo/RoutesTest.php b/tests/unit/AppInfo/RoutesTest.php
new file mode 100644
index 000000000..ba15a2c98
--- /dev/null
+++ b/tests/unit/AppInfo/RoutesTest.php
@@ -0,0 +1,61 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCA\Assistant\Tests\Unit\AppInfo;
+
+use PHPUnit\Framework\TestCase;
+
+/**
+ * Pins the URL contract between the registered OCS route for output file
+ * info and the URLs the display components build. The frontend half is a
+ * source-text check, not a behavioral test: the repository has no
+ * frontend test tooling yet, so it is a drift tripwire against accidental
+ * edits, not a guarantee of the URL actually requested.
+ */
+class RoutesTest extends TestCase {
+
+	/**
+	 * The output file info route stays registered with the expected URL
+	 * shape and verb.
+	 */
+	public function testOutputFileInfoRouteIsRegisteredWithExpectedUrl(): void {
+		$routes = require __DIR__ . '/../../../appinfo/routes.php';
+		self::assertArrayHasKey('ocs', $routes);
+
+		$match = null;
+		foreach ($routes['ocs'] as $route) {
+			if (($route['name'] ?? null) === 'assistantApi#getOutputFileInfo') {
+				$match = $route;
+				break;
+			}
+		}
+
+		self::assertNotNull($match, 'the assistantApi#getOutputFileInfo route must stay registered');
+		self::assertSame('/api/{apiVersion}/task/{ocpTaskId}/output-file/{fileId}/info', $match['url']);
+		self::assertSame('GET', $match['verb']);
+	}
+
+	/**
+	 * Source-text check: both display components keep building the output
+	 * file info URL the registered route expects. This does not assert the
+	 * argument passed to axios.get; a frontend unit test would, but the
+	 * repository has no frontend test tooling yet.
+	 */
+	public function testDisplayComponentsBuildOutputFileInfoUrlInSource(): void {
+		foreach (['FileDisplay.vue', 'ImageDisplay.vue'] as $componentName) {
+			$component = file_get_contents(__DIR__ . '/../../../src/components/fields/' . $componentName);
+			self::assertIsString($component, $componentName . ' must exist');
+			self::assertStringContainsString(
+				'task/{taskId}/output-file/{fileId}/info',
+				$component,
+				$componentName . ' must keep building the output file info URL for the registered route'
+			);
+		}
+	}
+}
diff --git a/tests/unit/Service/AssistantServiceTest.php b/tests/unit/Service/AssistantServiceTest.php
new file mode 100644
index 000000000..af4230d78
--- /dev/null
+++ b/tests/unit/Service/AssistantServiceTest.php
@@ -0,0 +1,219 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCA\Assistant\Tests\Unit\Service;
+
+use OCA\Assistant\Db\TaskNotificationMapper;
+use OCA\Assistant\Service\AssistantService;
+use OCA\Assistant\Service\NotificationService;
+use OCA\Assistant\Service\PreviewService;
+use OCA\Assistant\Service\SystemTagService;
+use OCP\DB\Exception as DBException;
+use OCP\Files\File;
+use OCP\Files\Folder;
+use OCP\Files\IRootFolder;
+use OCP\IAppConfig;
+use OCP\IConfig;
+use OCP\IL10N;
+use OCP\ITempManager;
+use OCP\Share\IManager as IShareManager;
+use OCP\TaskProcessing\EShapeType;
+use OCP\TaskProcessing\Exception\NotFoundException as TaskProcessingNotFoundException;
+use OCP\TaskProcessing\IManager as ITaskProcessingManager;
+use OCP\TaskProcessing\ShapeDescriptor;
+use OCP\TaskProcessing\Task;
+use PHPUnit\Framework\MockObject\MockObject;
+use PHPUnit\Framework\TestCase;
+use Psr\Log\LoggerInterface;
+
+/**
+ * Unit tests for AssistantService::getTaskOutputFileInfo
+ *
+ * Covers the authorization and resolution logic delegated to getTaskOutputFile
+ * and the shape of the returned info array.
+ */
+class AssistantServiceTest extends TestCase {
+
+	private const TASK_ID = 42;
+	private const FILE_ID = 4242;
+	private const USER_ID = 'assistant_service_test_user';
+
+	private ITaskProcessingManager&MockObject $taskProcessingManager;
+	private IRootFolder&MockObject $rootFolder;
+	private AssistantService $service;
+
+	protected function setUp(): void {
+		parent::setUp();
+
+		$this->taskProcessingManager = $this->createMock(ITaskProcessingManager::class);
+		$this->rootFolder = $this->createMock(IRootFolder::class);
+
+		$this->taskProcessingManager->method('getAvailableTaskTypes')
+			->willReturn([
+				'test:tasktype' => [
+					'name' => 'Test task type',
+					'description' => 'A test task type',
+					'inputShape' => [],
+					'optionalInputShape' => [],
+					'outputShape' => [
+						'result' => new ShapeDescriptor('Result', 'The result file', EShapeType::File),
+					],
+					'optionalOutputShape' => [],
+				],
+			]);
+
+		$this->service = new AssistantService(
+			$this->taskProcessingManager,
+			$this->createMock(TaskNotificationMapper::class),
+			$this->createMock(NotificationService::class),
+			$this->createMock(PreviewService::class),
+			$this->createMock(LoggerInterface::class),
+			$this->rootFolder,
+			$this->createMock(IL10N::class),
+			$this->createMock(ITempManager::class),
+			$this->createMock(IConfig::class),
+			$this->createMock(IAppConfig::class),
+			$this->createMock(IShareManager::class),
+			$this->createMock(SystemTagService::class),
+		);
+	}
+
+	private function getTask(string $userId): Task {
+		$task = new Task(
+			'test:tasktype',
+			[],
+			'assistant',
+			$userId,
+		);
+		$task->setId(self::TASK_ID);
+		$task->setOutput(['result' => self::FILE_ID]);
+		return $task;
+	}
+
+	private function getOutputFile(): File&MockObject {
+		$file = $this->createMock(File::class);
+		$file->method('getName')->willReturn('result.txt');
+		$file->method('getSize')->willReturn(1024);
+		return $file;
+	}
+
+	/**
+	 * An output file of the user's own task resolves to name and size.
+	 */
+	public function testGetTaskOutputFileInfo(): void {
+		$this->taskProcessingManager->method('getTask')
+			->with(self::TASK_ID)
+			->willReturn($this->getTask(self::USER_ID));
+		$this->rootFolder->method('getFirstNodeById')
+			->with(self::FILE_ID)
+			->willReturn($this->getOutputFile());
+
+		$fileInfo = $this->service->getTaskOutputFileInfo(self::USER_ID, self::TASK_ID, self::FILE_ID);
+
+		$this->assertSame([
+			'name' => 'result.txt',
+			'size' => 1024,
+		], $fileInfo);
+	}
+
+	/**
+	 * An output file stored in appdata instead of the user folder still
+	 * resolves through the appdata path lookup.
+	 */
+	public function testGetTaskOutputFileInfoForAppdataFile(): void {
+		$this->taskProcessingManager->method('getTask')
+			->with(self::TASK_ID)
+			->willReturn($this->getTask(self::USER_ID));
+		$this->rootFolder->method('getFirstNodeById')
+			->with(self::FILE_ID)
+			->willReturn(null);
+		$this->rootFolder->method('getAppDataDirectoryName')
+			->willReturn('assistant');
+		$this->rootFolder->method('getFirstNodeByIdInPath')
+			->with(self::FILE_ID, '/assistant/')
+			->willReturn($this->getOutputFile());
+
+		$fileInfo = $this->service->getTaskOutputFileInfo(self::USER_ID, self::TASK_ID, self::FILE_ID);
+
+		$this->assertSame([
+			'name' => 'result.txt',
+			'size' => 1024,
+		], $fileInfo);
+	}
+
+	/**
+	 * A user cannot fetch output file info of another user's task.
+	 */
+	public function testGetTaskOutputFileInfoWrongUser(): void {
+		$this->taskProcessingManager->method('getTask')
+			->with(self::TASK_ID)
+			->willReturn($this->getTask(self::USER_ID));
+
+		$this->expectException(DBException::class);
+		$this->expectExceptionMessage('Unauthorized');
+
+		$this->service->getTaskOutputFileInfo('another_user', self::TASK_ID, self::FILE_ID);
+	}
+
+	/**
+	 * A file id that does not belong to the task is rejected as not found.
+	 */
+	public function testGetTaskOutputFileInfoUnknownFileId(): void {
+		$this->taskProcessingManager->method('getTask')
+			->with(self::TASK_ID)
+			->willReturn($this->getTask(self::USER_ID));
+
+		$this->expectException(DBException::class);
+		$this->expectExceptionMessage('Not found');
+
+		$this->service->getTaskOutputFileInfo(self::USER_ID, self::TASK_ID, 999999999);
+	}
+
+	/**
+	 * A node id that resolves to nothing at all is rejected as not a file.
+	 */
+	public function testGetTaskOutputFileInfoNotAFileNode(): void {
+		$this->taskProcessingManager->method('getTask')
+			->with(self::TASK_ID)
+			->willReturn($this->getTask(self::USER_ID));
+		$this->rootFolder->method('getFirstNodeById')
+			->with(self::FILE_ID)
+			->willReturn(null);
+		$this->rootFolder->method('getAppDataDirectoryName')
+			->willReturn('assistant');
+		$this->rootFolder->method('getFirstNodeByIdInPath')
+			->with(self::FILE_ID, '/assistant/')
+			->willReturn(null);
+
+		$this->expectException(TaskProcessingNotFoundException::class);
+		$this->expectExceptionMessage('Node is not a file');
+
+		$this->service->getTaskOutputFileInfo(self::USER_ID, self::TASK_ID, self::FILE_ID);
+	}
+
+	/**
+	 * A node id that resolves to a non-file node (for example a folder)
+	 * through the root lookup is rejected exactly like the missing case,
+	 * so the instance check cannot be dropped without a failing test.
+	 */
+	public function testGetTaskOutputFileInfoNotAFolderNode(): void {
+		$folder = $this->createMock(Folder::class);
+		$this->taskProcessingManager->method('getTask')
+			->with(self::TASK_ID)
+			->willReturn($this->getTask(self::USER_ID));
+		$this->rootFolder->method('getFirstNodeById')
+			->with(self::FILE_ID)
+			->willReturn($folder);
+
+		$this->expectException(TaskProcessingNotFoundException::class);
+		$this->expectExceptionMessage('Node is not a file');
+
+		$this->service->getTaskOutputFileInfo(self::USER_ID, self::TASK_ID, self::FILE_ID);
+	}
+}