diff --git a/CHANGELOG.md b/CHANGELOG.md
index ba4733e..5b82df2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,7 @@ Latest
 ------
 
 ### Changes
+* [#51](https://github.com/cleverage/flysystem-process-bundle/issues/51) Give a code to the tasks ([cleverage/process-bundle#91](https://github.com/cleverage/process-bundle/issues/91)): `flysystem_file_fetch`, `flysystem_list_content` and `flysystem_remove_file` (`task: flysystem_file_fetch`, with `cleverage/process-bundle` 5.4 or later, referencing them by `service` being deprecated there). The tasks have their class name as service id; fetching them directly from the service container is deprecated (`container.private`), they will be private in 4.0. The former ids `cleverage_flysystem_process.task.file_fetch` / `cleverage_flysystem_process.task.list_content` / `cleverage_flysystem_process.task.remove_file` are deprecated aliases, removed in 4.0. Update documentation, add tests.
 * [#49](https://github.com/cleverage/flysystem-process-bundle/issues/49) CI: test the lowest versions allowed by `composer.json` (`--prefer-lowest`, PHP 8.2). Require `psr/log` `^2|^3`: `cleverage/process-bundle` 5.x uses the typed `LoggerInterface` signatures (fatal error with `psr/log` 1).
 * [#47](https://github.com/cleverage/flysystem-process-bundle/issues/47) Add a `.gitattributes`: the development files (`.docker/`, `.github/`, `tests/`, quality tools and PHPUnit configurations, `Makefile`) are no longer part of the archive installed by Composer (`dist`).
 * [#45](https://github.com/cleverage/flysystem-process-bundle/issues/45) Require `league/flysystem` and `psr/log`, used directly by the tasks but only installed through `league/flysystem-bundle` and `cleverage/process-bundle`; add `league/flysystem-local` (used by the tests) to the dev requirements.
diff --git a/config/services/task.yaml b/config/services/task.yaml
index b74eb90..83fad06 100644
--- a/config/services/task.yaml
+++ b/config/services/task.yaml
@@ -1,31 +1,48 @@
 services:
     _defaults:
-        public: false
+        # Public for the direct access from the service container, deprecated since 3.3: private in 4.0
+        public: true
         tags:
             - { name: monolog.logger, channel: cleverage_process_task }
+            - { name: container.private, package: cleverage/flysystem-process-bundle, version: '3.3' }
 
-    cleverage_flysystem_process.task.file_fetch:
-        class: CleverAge\FlysystemProcessBundle\Task\FileFetchTask
+    CleverAge\FlysystemProcessBundle\Task\FileFetchTask:
         shared: false
         arguments: [!tagged_locator { tag: 'flysystem.storage', index_by: 'storage' }]
-    CleverAge\FlysystemProcessBundle\Task\FileFetchTask:
-        alias: cleverage_flysystem_process.task.file_fetch
-        public: true
+        tags:
+            - { name: cleverage.task, code: flysystem_file_fetch }
+    cleverage_flysystem_process.task.file_fetch:
+        alias: CleverAge\FlysystemProcessBundle\Task\FileFetchTask
+        public: false
+        deprecated:
+            package: cleverage/flysystem-process-bundle
+            version: '3.3'
+            message: 'The "%alias_id%" service alias is deprecated, use the "flysystem_file_fetch" task code or the class name of the task instead. It will be removed in 4.0.'
 
-    cleverage_flysystem_process.task.list_content:
-        class: CleverAge\FlysystemProcessBundle\Task\ListContentTask
+    CleverAge\FlysystemProcessBundle\Task\ListContentTask:
         shared: false
         arguments: [!tagged_locator { tag: 'flysystem.storage', index_by: 'storage' }]
-    CleverAge\FlysystemProcessBundle\Task\ListContentTask:
-        alias: cleverage_flysystem_process.task.list_content
-        public: true
+        tags:
+            - { name: cleverage.task, code: flysystem_list_content }
+    cleverage_flysystem_process.task.list_content:
+        alias: CleverAge\FlysystemProcessBundle\Task\ListContentTask
+        public: false
+        deprecated:
+            package: cleverage/flysystem-process-bundle
+            version: '3.3'
+            message: 'The "%alias_id%" service alias is deprecated, use the "flysystem_list_content" task code or the class name of the task instead. It will be removed in 4.0.'
 
-    cleverage_flysystem_process.task.remove_file:
-        class: CleverAge\FlysystemProcessBundle\Task\RemoveFileTask
+    CleverAge\FlysystemProcessBundle\Task\RemoveFileTask:
         shared: false
         arguments:
             - '@logger'
             - !tagged_locator { tag: 'flysystem.storage', index_by: 'storage' }
-    CleverAge\FlysystemProcessBundle\Task\RemoveFileTask:
-        alias: cleverage_flysystem_process.task.remove_file
-        public: true
+        tags:
+            - { name: cleverage.task, code: flysystem_remove_file }
+    cleverage_flysystem_process.task.remove_file:
+        alias: CleverAge\FlysystemProcessBundle\Task\RemoveFileTask
+        public: false
+        deprecated:
+            package: cleverage/flysystem-process-bundle
+            version: '3.3'
+            message: 'The "%alias_id%" service alias is deprecated, use the "flysystem_remove_file" task code or the class name of the task instead. It will be removed in 4.0.'
diff --git a/docs/cookbooks/remote_cleanup.md b/docs/cookbooks/remote_cleanup.md
index 3d79682..73702a3 100644
--- a/docs/cookbooks/remote_cleanup.md
+++ b/docs/cookbooks/remote_cleanup.md
@@ -12,27 +12,27 @@ clever_age_process:
             help: "bin/console cleverage:process:execute app.remote_cleanup -c year:2025"
             tasks:
                 list:
-                    service: '@CleverAge\FlysystemProcessBundle\Task\ListContentTask'
+                    task: flysystem_list_content
                     options:
                         filesystem: 'remote.storage.archive'
                         file_pattern: '/^catalog_{{ year }}.*\.csv$/'
                     outputs: [only_files]
 
                 only_files:
-                    service: '@CleverAge\ProcessBundle\Task\FilterTask'
+                    task: filter
                     options:
                         match:
                             type: 'file'
                     outputs: [get_path]
 
                 get_path:
-                    service: '@CleverAge\ProcessBundle\Task\PropertyGetterTask'
+                    task: property_getter
                     options:
                         property: 'path'
                     outputs: [remove]
 
                 remove:
-                    service: '@CleverAge\FlysystemProcessBundle\Task\RemoveFileTask'
+                    task: flysystem_remove_file
                     options:
                         filesystem: 'remote.storage.archive'
 ```
@@ -59,7 +59,7 @@ clever_age_process:
         app.remote_cleanup_pattern:
             tasks:
                 remove:
-                    service: '@CleverAge\FlysystemProcessBundle\Task\RemoveFileTask'
+                    task: flysystem_remove_file
                     options:
                         filesystem: 'remote.storage.archive'
                         file_pattern: '/^catalog_{{ year }}.*\.csv$/'
diff --git a/docs/cookbooks/sftp_export.md b/docs/cookbooks/sftp_export.md
index 17a03d0..13dc18f 100644
--- a/docs/cookbooks/sftp_export.md
+++ b/docs/cookbooks/sftp_export.md
@@ -14,7 +14,7 @@ clever_age_process:
             description: 'Export the catalog to the SFTP server'
             tasks:
                 data:
-                    service: '@CleverAge\ProcessBundle\Task\ConstantIterableOutputTask' # Replace with your own reader
+                    task: constant_iterable_output # Replace with your own reader
                     options:
                         output:
                             - { sku: 'SKU-001', name: 'Product 1', price: '12.50' }
@@ -22,14 +22,14 @@ clever_age_process:
                     outputs: [write]
 
                 write:
-                    service: '@CleverAge\ProcessBundle\Task\File\Csv\CsvWriterTask'
+                    task: csv_writer
                     options:
                         file_path: '%local.storage.dir%/catalog_{date_time}.csv'
                         headers: [sku, name, price]
                     outputs: [relative_path]
 
                 relative_path:
-                    service: '@CleverAge\ProcessBundle\Task\TransformerTask'
+                    task: transformer
                     options:
                         transformers:
                             callback:
@@ -37,7 +37,7 @@ clever_age_process:
                     outputs: [upload]
 
                 upload:
-                    service: '@CleverAge\FlysystemProcessBundle\Task\FileFetchTask'
+                    task: flysystem_file_fetch
                     options:
                         source_filesystem: 'local.storage'
                         destination_filesystem: 'remote.storage.outgoing'
@@ -45,7 +45,7 @@ clever_age_process:
                     outputs: [log_upload]
 
                 log_upload:
-                    service: '@CleverAge\ProcessBundle\Task\Reporting\LoggerTask'
+                    task: logger
                     options:
                         level: info
                         message: 'File uploaded'
diff --git a/docs/cookbooks/sftp_import.md b/docs/cookbooks/sftp_import.md
index 8c508a5..daabc4e 100644
--- a/docs/cookbooks/sftp_import.md
+++ b/docs/cookbooks/sftp_import.md
@@ -43,7 +43,7 @@ clever_age_process:
             description: 'Import the CSV files dropped on the SFTP server'
             tasks:
                 fetch:
-                    service: '@CleverAge\FlysystemProcessBundle\Task\FileFetchTask'
+                    task: flysystem_file_fetch
                     options:
                         source_filesystem: 'remote.storage.incoming'
                         destination_filesystem: 'local.storage'
@@ -51,20 +51,20 @@ clever_age_process:
                     outputs: [read, archive] # "archive" is executed once "read" has read the whole file
 
                 read:
-                    service: '@CleverAge\ProcessBundle\Task\File\Csv\InputCsvReaderTask'
+                    task: input_csv_reader
                     options:
                         base_path: '%local.storage.dir%'
                         delimiter: ';'
                     outputs: [import_line]
 
                 import_line:
-                    service: '@CleverAge\ProcessBundle\Task\Reporting\LoggerTask' # Replace with your own transformation and writer tasks
+                    task: logger # Replace with your own transformation and writer tasks
                     options:
                         level: info
                         message: 'Imported line'
 
                 archive:
-                    service: '@CleverAge\FlysystemProcessBundle\Task\FileFetchTask'
+                    task: flysystem_file_fetch
                     options:
                         source_filesystem: 'remote.storage.incoming'
                         destination_filesystem: 'remote.storage.archive'
@@ -72,7 +72,7 @@ clever_age_process:
                     outputs: [cleanup_local]
 
                 cleanup_local:
-                    service: '@CleverAge\FlysystemProcessBundle\Task\RemoveFileTask'
+                    task: flysystem_remove_file
                     options:
                         filesystem: 'local.storage'
 ```
diff --git a/docs/index.md b/docs/index.md
index 180eb8b..a4691eb 100644
--- a/docs/index.md
+++ b/docs/index.md
@@ -25,6 +25,17 @@ require their own package, e.g. `composer require league/flysystem-sftp-v3` for
 
 ## Configuration
 
+The tasks of this bundle are registered as services (non-shared) and are used in your processes by their code,
+`flysystem_file_fetch`, `flysystem_list_content` and `flysystem_remove_file` (e.g. `task: flysystem_file_fetch`, requires
+`cleverage/process-bundle` 5.4 or later, see its [task definition](https://github.com/cleverage/process-bundle/blob/main/docs/reference/02-task_definition.md)).
+Referencing them by their class name (`service: '@CleverAge\FlysystemProcessBundle\Task\FileFetchTask'`) is
+deprecated since `cleverage/process-bundle` 5.4.
+
+Their service id is their class name. Fetching them directly from the service container is deprecated since 3.3 (they
+will be private in 4.0); their former ids, `cleverage_flysystem_process.task.file_fetch`,
+`cleverage_flysystem_process.task.list_content` and `cleverage_flysystem_process.task.remove_file`, are deprecated
+aliases since 3.3, removed in 4.0.
+
 The tasks of this bundle work with the Flysystem **storages** configured in `config/packages/flysystem.yaml`: their
 `filesystem`, `source_filesystem` and `destination_filesystem` options take the name of a storage (the key under
 `flysystem.storages`). Configure at least one storage:
diff --git a/docs/reference/tasks/_template.md b/docs/reference/tasks/_template.md
index 919390a..d4545a0 100644
--- a/docs/reference/tasks/_template.md
+++ b/docs/reference/tasks/_template.md
@@ -7,6 +7,7 @@ Task reference
 --------------
 
 * **Service**: `Fully\Qualified\ClassName`
+* **Code**: `flysystem_task_code` (`task: flysystem_task_code`)
 * **Iterable task** _(only if it implements `IterableTaskInterface`)_
 * **Blocking task** _(only if it implements `BlockingTaskInterface`)_
 * **Flushable task** _(only if it implements `FlushableTaskInterface`)_
@@ -39,7 +40,7 @@ Examples
 ```yaml
 # Task configuration level
 code:
-  service: '@Fully\Qualified\ClassName'
+  task: flysystem_task_code
   options:
     a: 1
     b: 2
diff --git a/docs/reference/tasks/file_fetch_task.md b/docs/reference/tasks/file_fetch_task.md
index ca05c04..e3f2340 100644
--- a/docs/reference/tasks/file_fetch_task.md
+++ b/docs/reference/tasks/file_fetch_task.md
@@ -11,6 +11,7 @@ Task reference
 --------------
 
 * **Service**: `CleverAge\FlysystemProcessBundle\Task\FileFetchTask`
+* **Code**: `flysystem_file_fetch` (`task: flysystem_file_fetch`)
 * **Iterable task**
 
 Accepted inputs
@@ -55,7 +56,7 @@ Examples
 ```yaml
 # Task configuration level
 fetch:
-  service: '@CleverAge\FlysystemProcessBundle\Task\FileFetchTask'
+  task: flysystem_file_fetch
   options:
     source_filesystem: 'remote.storage'
     destination_filesystem: 'local.storage'
@@ -74,7 +75,7 @@ my_process:
   entry_point: copy_from_input
   tasks:
     copy_from_input:
-      service: '@CleverAge\FlysystemProcessBundle\Task\FileFetchTask'
+      task: flysystem_file_fetch
       options:
         source_filesystem: '{{ source }}'
         destination_filesystem: '{{ destination }}'
@@ -86,7 +87,7 @@ my_process:
 ```yaml
 # Task configuration level
 archive:
-  service: '@CleverAge\FlysystemProcessBundle\Task\FileFetchTask'
+  task: flysystem_file_fetch
   options:
     source_filesystem: 'remote.storage.incoming'
     destination_filesystem: 'remote.storage.archive'
diff --git a/docs/reference/tasks/list_content_task.md b/docs/reference/tasks/list_content_task.md
index 1db9737..0499325 100644
--- a/docs/reference/tasks/list_content_task.md
+++ b/docs/reference/tasks/list_content_task.md
@@ -8,6 +8,7 @@ Task reference
 --------------
 
 * **Service**: `CleverAge\FlysystemProcessBundle\Task\ListContentTask`
+* **Code**: `flysystem_list_content` (`task: flysystem_list_content`)
 * **Iterable task**
 
 Accepted inputs
@@ -45,13 +46,13 @@ Examples
 ```yaml
 # Task configuration level
 list:
-  service: '@CleverAge\FlysystemProcessBundle\Task\ListContentTask'
+  task: flysystem_list_content
   options:
     filesystem: 'remote.storage'
     file_pattern: '/\.csv$/'
   outputs: [get_path]
 get_path:
-  service: '@CleverAge\ProcessBundle\Task\PropertyGetterTask'
+  task: property_getter
   options:
     property: 'path'
   outputs: [log]
@@ -63,12 +64,12 @@ get_path:
 ```yaml
 # Task configuration level
 list:
-  service: '@CleverAge\FlysystemProcessBundle\Task\ListContentTask'
+  task: flysystem_list_content
   options:
     filesystem: 'remote.storage'
   outputs: [only_files]
 only_files:
-  service: '@CleverAge\ProcessBundle\Task\FilterTask'
+  task: filter
   options:
     match:
       type: 'file'
diff --git a/docs/reference/tasks/remove_file_task.md b/docs/reference/tasks/remove_file_task.md
index be9af89..6f7a667 100644
--- a/docs/reference/tasks/remove_file_task.md
+++ b/docs/reference/tasks/remove_file_task.md
@@ -7,6 +7,7 @@ Task reference
 --------------
 
 * **Service**: `CleverAge\FlysystemProcessBundle\Task\RemoveFileTask`
+* **Code**: `flysystem_remove_file` (`task: flysystem_remove_file`)
 
 Accepted inputs
 ---------------
@@ -42,7 +43,7 @@ my_process:
   entry_point: remove_from_input
   tasks:
     remove_from_input:
-      service: '@CleverAge\FlysystemProcessBundle\Task\RemoveFileTask'
+      task: flysystem_remove_file
       options:
         filesystem: 'remote.storage'
 ```
@@ -52,7 +53,7 @@ my_process:
 ```yaml
 # Task configuration level
 purge:
-  service: '@CleverAge\FlysystemProcessBundle\Task\RemoveFileTask'
+  task: flysystem_remove_file
   options:
     filesystem: 'remote.storage'
     file_pattern: '/\.csv$/'
diff --git a/tests/DependencyInjection/CleverAgeFlysystemProcessExtensionTest.php b/tests/DependencyInjection/CleverAgeFlysystemProcessExtensionTest.php
index 08691d2..cea6766 100644
--- a/tests/DependencyInjection/CleverAgeFlysystemProcessExtensionTest.php
+++ b/tests/DependencyInjection/CleverAgeFlysystemProcessExtensionTest.php
@@ -28,28 +28,33 @@
 class CleverAgeFlysystemProcessExtensionTest extends TestCase
 {
     /**
-     * @return iterable<string, array{string, class-string}>
+     * @return iterable<string, array{class-string, string, string}>
      */
     public static function provideTasks(): iterable
     {
-        yield 'file_fetch' => ['cleverage_flysystem_process.task.file_fetch', FileFetchTask::class];
-        yield 'list_content' => ['cleverage_flysystem_process.task.list_content', ListContentTask::class];
-        yield 'remove_file' => ['cleverage_flysystem_process.task.remove_file', RemoveFileTask::class];
+        yield 'file_fetch' => [FileFetchTask::class, 'flysystem_file_fetch', 'cleverage_flysystem_process.task.file_fetch'];
+        yield 'list_content' => [ListContentTask::class, 'flysystem_list_content', 'cleverage_flysystem_process.task.list_content'];
+        yield 'remove_file' => [RemoveFileTask::class, 'flysystem_remove_file', 'cleverage_flysystem_process.task.remove_file'];
     }
 
     /**
      * @param class-string $class
      */
     #[DataProvider('provideTasks')]
-    public function testTaskIsRegistered(string $id, string $class): void
+    public function testTaskIsRegistered(string $class, string $code, string $deprecatedId): void
     {
         $container = new ContainerBuilder();
         (new CleverAgeFlysystemProcessExtension())->load([], $container);
 
-        $definition = $container->getDefinition($id);
-        self::assertSame($class, $definition->getClass());
+        // The class name is the service id
+        $definition = $container->getDefinition($class);
         // Tasks are stateful: each process execution must get its own instance
         self::assertFalse($definition->isShared());
+        // Referenced by its code in the process configurations (task: <code>)
+        self::assertSame([['code' => $code]], $definition->getTag('cleverage.task'));
+        // Public for the direct access from the service container, deprecated
+        self::assertTrue($definition->isPublic());
+        self::assertSame([['package' => 'cleverage/flysystem-process-bundle', 'version' => '3.3']], $definition->getTag('container.private'));
 
         // The Flysystem storages, indexed by name
         $storages = array_values(array_filter(
@@ -62,10 +67,15 @@ public function testTaskIsRegistered(string $id, string $class): void
         self::assertSame('flysystem.storage', $taggedIterator->getTag());
         self::assertSame('storage', $taggedIterator->getIndexAttribute());
 
-        // Referenced as '@<class>' in process configurations
-        $alias = $container->getAlias($class);
-        self::assertSame($id, (string) $alias);
-        self::assertTrue($alias->isPublic());
+        // Former id, deprecated
+        $alias = $container->getAlias($deprecatedId);
+        self::assertSame($class, (string) $alias);
+        self::assertFalse($alias->isPublic());
+        self::assertTrue($alias->isDeprecated());
+        self::assertSame(
+            ['package' => 'cleverage/flysystem-process-bundle', 'version' => '3.3', 'message' => 'The "'.$deprecatedId.'" service alias is deprecated, use the "'.$code.'" task code or the class name of the task instead. It will be removed in 4.0.'],
+            $alias->getDeprecation($deprecatedId)
+        );
     }
 
     public function testEveryTaskIsTested(): void
@@ -75,7 +85,7 @@ public function testEveryTaskIsTested(): void
 
         $ids = array_filter(
             array_keys($container->getDefinitions()),
-            static fn (string $id): bool => str_starts_with($id, 'cleverage_flysystem_process.task.')
+            static fn (string $id): bool => str_starts_with($id, 'CleverAge\\FlysystemProcessBundle\\Task\\')
         );
         self::assertEqualsCanonicalizing(array_column(iterator_to_array(self::provideTasks()), 0), array_values($ids));
     }