From 666f0946f16489de11c747fe3c7f296b035021a7 Mon Sep 17 00:00:00 2001
From: Thomas S <thomas@probabl.ai>
Date: Tue, 7 Jan 2025 15:43:54 +0100
Subject: [PATCH 01/22] [skip ci] Move `item/` to `persistence/item/`

---
 skore/src/skore/{ => persistence}/item/__init__.py                | 0
 skore/src/skore/{ => persistence}/item/cross_validation_item.py   | 0
 skore/src/skore/{ => persistence}/item/item.py                    | 0
 skore/src/skore/{ => persistence}/item/media_item.py              | 0
 skore/src/skore/{ => persistence}/item/numpy_array_item.py        | 0
 skore/src/skore/{ => persistence}/item/pandas_dataframe_item.py   | 0
 skore/src/skore/{ => persistence}/item/pandas_series_item.py      | 0
 skore/src/skore/{ => persistence}/item/polars_dataframe_item.py   | 0
 skore/src/skore/{ => persistence}/item/polars_series_item.py      | 0
 skore/src/skore/{ => persistence}/item/primitive_item.py          | 0
 .../skore/{ => persistence}/item/sklearn_base_estimator_item.py   | 0
 skore/src/skore/{ => persistence}/item/skrub_table_report_item.py | 0
 .../src/skore/{ => persistence}/item/standalone_widget.html.jinja | 0
 skore/src/skore/persistence/repository/__init__.py                | 0
 .../src/skore/{item => persistence/repository}/item_repository.py | 0
 skore/src/skore/persistence/{ => storage}/abstract_storage.py     | 0
 skore/src/skore/persistence/{ => storage}/disk_cache_storage.py   | 0
 skore/src/skore/persistence/{ => storage}/in_memory_storage.py    | 0
 18 files changed, 0 insertions(+), 0 deletions(-)
 rename skore/src/skore/{ => persistence}/item/__init__.py (100%)
 rename skore/src/skore/{ => persistence}/item/cross_validation_item.py (100%)
 rename skore/src/skore/{ => persistence}/item/item.py (100%)
 rename skore/src/skore/{ => persistence}/item/media_item.py (100%)
 rename skore/src/skore/{ => persistence}/item/numpy_array_item.py (100%)
 rename skore/src/skore/{ => persistence}/item/pandas_dataframe_item.py (100%)
 rename skore/src/skore/{ => persistence}/item/pandas_series_item.py (100%)
 rename skore/src/skore/{ => persistence}/item/polars_dataframe_item.py (100%)
 rename skore/src/skore/{ => persistence}/item/polars_series_item.py (100%)
 rename skore/src/skore/{ => persistence}/item/primitive_item.py (100%)
 rename skore/src/skore/{ => persistence}/item/sklearn_base_estimator_item.py (100%)
 rename skore/src/skore/{ => persistence}/item/skrub_table_report_item.py (100%)
 rename skore/src/skore/{ => persistence}/item/standalone_widget.html.jinja (100%)
 create mode 100644 skore/src/skore/persistence/repository/__init__.py
 rename skore/src/skore/{item => persistence/repository}/item_repository.py (100%)
 rename skore/src/skore/persistence/{ => storage}/abstract_storage.py (100%)
 rename skore/src/skore/persistence/{ => storage}/disk_cache_storage.py (100%)
 rename skore/src/skore/persistence/{ => storage}/in_memory_storage.py (100%)

diff --git a/skore/src/skore/item/__init__.py b/skore/src/skore/persistence/item/__init__.py
similarity index 100%
rename from skore/src/skore/item/__init__.py
rename to skore/src/skore/persistence/item/__init__.py
diff --git a/skore/src/skore/item/cross_validation_item.py b/skore/src/skore/persistence/item/cross_validation_item.py
similarity index 100%
rename from skore/src/skore/item/cross_validation_item.py
rename to skore/src/skore/persistence/item/cross_validation_item.py
diff --git a/skore/src/skore/item/item.py b/skore/src/skore/persistence/item/item.py
similarity index 100%
rename from skore/src/skore/item/item.py
rename to skore/src/skore/persistence/item/item.py
diff --git a/skore/src/skore/item/media_item.py b/skore/src/skore/persistence/item/media_item.py
similarity index 100%
rename from skore/src/skore/item/media_item.py
rename to skore/src/skore/persistence/item/media_item.py
diff --git a/skore/src/skore/item/numpy_array_item.py b/skore/src/skore/persistence/item/numpy_array_item.py
similarity index 100%
rename from skore/src/skore/item/numpy_array_item.py
rename to skore/src/skore/persistence/item/numpy_array_item.py
diff --git a/skore/src/skore/item/pandas_dataframe_item.py b/skore/src/skore/persistence/item/pandas_dataframe_item.py
similarity index 100%
rename from skore/src/skore/item/pandas_dataframe_item.py
rename to skore/src/skore/persistence/item/pandas_dataframe_item.py
diff --git a/skore/src/skore/item/pandas_series_item.py b/skore/src/skore/persistence/item/pandas_series_item.py
similarity index 100%
rename from skore/src/skore/item/pandas_series_item.py
rename to skore/src/skore/persistence/item/pandas_series_item.py
diff --git a/skore/src/skore/item/polars_dataframe_item.py b/skore/src/skore/persistence/item/polars_dataframe_item.py
similarity index 100%
rename from skore/src/skore/item/polars_dataframe_item.py
rename to skore/src/skore/persistence/item/polars_dataframe_item.py
diff --git a/skore/src/skore/item/polars_series_item.py b/skore/src/skore/persistence/item/polars_series_item.py
similarity index 100%
rename from skore/src/skore/item/polars_series_item.py
rename to skore/src/skore/persistence/item/polars_series_item.py
diff --git a/skore/src/skore/item/primitive_item.py b/skore/src/skore/persistence/item/primitive_item.py
similarity index 100%
rename from skore/src/skore/item/primitive_item.py
rename to skore/src/skore/persistence/item/primitive_item.py
diff --git a/skore/src/skore/item/sklearn_base_estimator_item.py b/skore/src/skore/persistence/item/sklearn_base_estimator_item.py
similarity index 100%
rename from skore/src/skore/item/sklearn_base_estimator_item.py
rename to skore/src/skore/persistence/item/sklearn_base_estimator_item.py
diff --git a/skore/src/skore/item/skrub_table_report_item.py b/skore/src/skore/persistence/item/skrub_table_report_item.py
similarity index 100%
rename from skore/src/skore/item/skrub_table_report_item.py
rename to skore/src/skore/persistence/item/skrub_table_report_item.py
diff --git a/skore/src/skore/item/standalone_widget.html.jinja b/skore/src/skore/persistence/item/standalone_widget.html.jinja
similarity index 100%
rename from skore/src/skore/item/standalone_widget.html.jinja
rename to skore/src/skore/persistence/item/standalone_widget.html.jinja
diff --git a/skore/src/skore/persistence/repository/__init__.py b/skore/src/skore/persistence/repository/__init__.py
new file mode 100644
index 000000000..e69de29bb
diff --git a/skore/src/skore/item/item_repository.py b/skore/src/skore/persistence/repository/item_repository.py
similarity index 100%
rename from skore/src/skore/item/item_repository.py
rename to skore/src/skore/persistence/repository/item_repository.py
diff --git a/skore/src/skore/persistence/abstract_storage.py b/skore/src/skore/persistence/storage/abstract_storage.py
similarity index 100%
rename from skore/src/skore/persistence/abstract_storage.py
rename to skore/src/skore/persistence/storage/abstract_storage.py
diff --git a/skore/src/skore/persistence/disk_cache_storage.py b/skore/src/skore/persistence/storage/disk_cache_storage.py
similarity index 100%
rename from skore/src/skore/persistence/disk_cache_storage.py
rename to skore/src/skore/persistence/storage/disk_cache_storage.py
diff --git a/skore/src/skore/persistence/in_memory_storage.py b/skore/src/skore/persistence/storage/in_memory_storage.py
similarity index 100%
rename from skore/src/skore/persistence/in_memory_storage.py
rename to skore/src/skore/persistence/storage/in_memory_storage.py

From 6811b6917ee306e1f9b48b4c89752f37050f81df Mon Sep 17 00:00:00 2001
From: Thomas S <thomas@probabl.ai>
Date: Tue, 7 Jan 2025 15:55:35 +0100
Subject: [PATCH 02/22] [skip ci] Move `view/` to `persistence/view`

---
 .../src/skore/{view => persistence/repository}/view_repository.py | 0
 skore/src/skore/{ => persistence}/view/__init__.py                | 0
 skore/src/skore/{ => persistence}/view/view.py                    | 0
 3 files changed, 0 insertions(+), 0 deletions(-)
 rename skore/src/skore/{view => persistence/repository}/view_repository.py (100%)
 rename skore/src/skore/{ => persistence}/view/__init__.py (100%)
 rename skore/src/skore/{ => persistence}/view/view.py (100%)

diff --git a/skore/src/skore/view/view_repository.py b/skore/src/skore/persistence/repository/view_repository.py
similarity index 100%
rename from skore/src/skore/view/view_repository.py
rename to skore/src/skore/persistence/repository/view_repository.py
diff --git a/skore/src/skore/view/__init__.py b/skore/src/skore/persistence/view/__init__.py
similarity index 100%
rename from skore/src/skore/view/__init__.py
rename to skore/src/skore/persistence/view/__init__.py
diff --git a/skore/src/skore/view/view.py b/skore/src/skore/persistence/view/view.py
similarity index 100%
rename from skore/src/skore/view/view.py
rename to skore/src/skore/persistence/view/view.py

From c08f284fe97449731600ba9bf5901c0edc0b2d6b Mon Sep 17 00:00:00 2001
From: Thomas S <thomas@probabl.ai>
Date: Tue, 7 Jan 2025 16:22:43 +0100
Subject: [PATCH 03/22] [skip ci] Remove `put_item`/`get_item`

---
 skore/src/skore/persistence/item/__init__.py | 27 +++++-
 skore/src/skore/project/project.py           | 92 ++++----------------
 2 files changed, 43 insertions(+), 76 deletions(-)

diff --git a/skore/src/skore/persistence/item/__init__.py b/skore/src/skore/persistence/item/__init__.py
index b7c89a040..0735647f5 100644
--- a/skore/src/skore/persistence/item/__init__.py
+++ b/skore/src/skore/persistence/item/__init__.py
@@ -43,7 +43,32 @@ def object_to_item(object: Any) -> Item:
             #     correct type. If not, they throw a ItemTypeError exception.
             return cls.factory(object)
 
-    raise NotImplementedError(f"Type '{object.__class__}' is not supported.")
+    return PickleItem(object)
+
+
+def item_to_object(item: Item) -> Any:
+    if isinstance(item, PrimitiveItem):
+        return item.primitive
+    elif isinstance(item, NumpyArrayItem):
+        return item.array
+    elif isinstance(item, PandasDataFrameItem):
+        return item.dataframe
+    elif isinstance(item, PandasSeriesItem):
+        return item.series
+    elif isinstance(item, PolarsDataFrameItem):
+        return item.dataframe
+    elif isinstance(item, PolarsSeriesItem):
+        return item.series
+    elif isinstance(item, SklearnBaseEstimatorItem):
+        return item.estimator
+    elif isinstance(item, CrossValidationItem):
+        return item.cv_results_serialized
+    elif isinstance(item, MediaItem):
+        return item.media_bytes
+    elif isinstance(item, PickleItem):
+        return repr(item.pickle_bytes)
+    else:
+        raise ValueError(f"Item {item} is not a known item type.")
 
 
 __all__ = [
diff --git a/skore/src/skore/project/project.py b/skore/src/skore/project/project.py
index 289b04d10..299409425 100644
--- a/skore/src/skore/project/project.py
+++ b/skore/src/skore/project/project.py
@@ -1,28 +1,18 @@
 """Define a Project."""
 
-import logging
-from typing import Any, Optional, Union
-
-from skore.item import (
-    CrossValidationItem,
-    Item,
-    ItemRepository,
-    MediaItem,
-    NumpyArrayItem,
-    PandasDataFrameItem,
-    PandasSeriesItem,
-    PolarsDataFrameItem,
-    PolarsSeriesItem,
-    PrimitiveItem,
-    SklearnBaseEstimatorItem,
-    object_to_item,
-)
-from skore.view.view import View
-from skore.view.view_repository import ViewRepository
-
-logger = logging.getLogger(__name__)
-logger.addHandler(logging.NullHandler())  # Default to no output
-logger.setLevel(logging.INFO)
+from __future__ import annotations
+
+from typing import TYPE_CHECKING, Any, Optional, Union
+
+from skore.persistence import item_to_object, object_to_item
+
+if TYPE_CHECKING:
+    from skore.persistence import (
+        Item,
+        ItemRepository,
+        View,
+        ViewRepository,
+    )
 
 
 MISSING = object()
@@ -128,28 +118,21 @@ def put(self, key: Union[str, dict[str, Any]], value: Optional[Any] = MISSING):
             If the value type is not supported.
         """
         if value is not MISSING:
-            key_to_item = {key: value}
+            key_to_value = {key: value}
         elif isinstance(key, dict):
-            key_to_item = key
+            key_to_value = key
         else:
             raise TypeError(
                 f"Bad parameters. "
                 f"When value is not specified, key must be a dict (found '{type(key)}')"
             )
 
-        for key, value in key_to_item.items():
+        for key, value in key_to_value.items():
             if not isinstance(key, str):
                 raise TypeError(f"Key must be a string (found '{type(key)}')")
 
             self.item_repository.put_item(key, object_to_item(value))
 
-    def put_item(self, key: str, item: Item):
-        """Add an Item to the Project."""
-        if not isinstance(key, str):
-            raise TypeError(f"Key must be a string (found '{type(key)}')")
-
-        self.item_repository.put_item(key, item)
-
     def get(self, key: str) -> Any:
         """Get the value corresponding to ``key`` from the Project.
 
@@ -163,48 +146,7 @@ def get(self, key: str) -> Any:
         KeyError
             If the key does not correspond to any item.
         """
-        item = self.get_item(key)
-
-        if isinstance(item, PrimitiveItem):
-            return item.primitive
-        elif isinstance(item, NumpyArrayItem):
-            return item.array
-        elif isinstance(item, PandasDataFrameItem):
-            return item.dataframe
-        elif isinstance(item, PandasSeriesItem):
-            return item.series
-        elif isinstance(item, PolarsDataFrameItem):
-            return item.dataframe
-        elif isinstance(item, PolarsSeriesItem):
-            return item.series
-        elif isinstance(item, SklearnBaseEstimatorItem):
-            return item.estimator
-        elif isinstance(item, CrossValidationItem):
-            return item.cv_results_serialized
-        elif isinstance(item, MediaItem):
-            return item.media_bytes
-        else:
-            raise ValueError(f"Item {item} is not a known item type.")
-
-    def get_item(self, key: str) -> Item:
-        """Get the item corresponding to ``key`` from the Project.
-
-        Parameters
-        ----------
-        key : str
-            The key corresponding to the item to get.
-
-        Returns
-        -------
-        item : Item
-            The Item corresponding to ``key``.
-
-        Raises
-        ------
-        KeyError
-            If the key does not correspond to any item.
-        """
-        return self.item_repository.get_item(key)
+        return item_to_object(self.item_repository.get_item(key))
 
     def get_item_versions(self, key: str) -> list[Item]:
         """

From 0277edb1f87125c48e4cb33b24f98d0274a29fba Mon Sep 17 00:00:00 2001
From: Thomas S <thomas@probabl.ai>
Date: Tue, 7 Jan 2025 16:40:14 +0100
Subject: [PATCH 04/22] [skip ci] Add `PickleItem`

---
 skore/src/skore/persistence/item/__init__.py  | 37 +++++++++----------
 .../src/skore/persistence/item/pickle_item.py | 25 +++++++++++++
 2 files changed, 43 insertions(+), 19 deletions(-)
 create mode 100644 skore/src/skore/persistence/item/pickle_item.py

diff --git a/skore/src/skore/persistence/item/__init__.py b/skore/src/skore/persistence/item/__init__.py
index 0735647f5..57e3b4c10 100644
--- a/skore/src/skore/persistence/item/__init__.py
+++ b/skore/src/skore/persistence/item/__init__.py
@@ -5,18 +5,19 @@
 from contextlib import suppress
 from typing import Any
 
-from skore.item import skrub_table_report_item as SkrubTableReportItem
-from skore.item.cross_validation_item import CrossValidationItem
-from skore.item.item import Item, ItemTypeError
-from skore.item.item_repository import ItemRepository
-from skore.item.media_item import MediaItem
-from skore.item.numpy_array_item import NumpyArrayItem
-from skore.item.pandas_dataframe_item import PandasDataFrameItem
-from skore.item.pandas_series_item import PandasSeriesItem
-from skore.item.polars_dataframe_item import PolarsDataFrameItem
-from skore.item.polars_series_item import PolarsSeriesItem
-from skore.item.primitive_item import PrimitiveItem
-from skore.item.sklearn_base_estimator_item import SklearnBaseEstimatorItem
+from .cross_validation_item import CrossValidationItem
+from .item import Item, ItemTypeError
+from .item_repository import ItemRepository
+from .media_item import MediaItem
+from .numpy_array_item import NumpyArrayItem
+from .pandas_dataframe_item import PandasDataFrameItem
+from .pandas_series_item import PandasSeriesItem
+from .pickle_item import PickleItem
+from .polars_dataframe_item import PolarsDataFrameItem
+from .polars_series_item import PolarsSeriesItem
+from .primitive_item import PrimitiveItem
+from .sklearn_base_estimator_item import SklearnBaseEstimatorItem
+from .skrub_table_report_item import SkrubTableReportItem
 
 
 def object_to_item(object: Any) -> Item:
@@ -51,13 +52,9 @@ def item_to_object(item: Item) -> Any:
         return item.primitive
     elif isinstance(item, NumpyArrayItem):
         return item.array
-    elif isinstance(item, PandasDataFrameItem):
+    elif isinstance(item, PandasDataFrameItem) or isinstance(item, PolarsDataFrameItem):
         return item.dataframe
-    elif isinstance(item, PandasSeriesItem):
-        return item.series
-    elif isinstance(item, PolarsDataFrameItem):
-        return item.dataframe
-    elif isinstance(item, PolarsSeriesItem):
+    elif isinstance(item, PandasSeriesItem) or isinstance(item, PolarsSeriesItem):
         return item.series
     elif isinstance(item, SklearnBaseEstimatorItem):
         return item.estimator
@@ -66,7 +63,7 @@ def item_to_object(item: Item) -> Any:
     elif isinstance(item, MediaItem):
         return item.media_bytes
     elif isinstance(item, PickleItem):
-        return repr(item.pickle_bytes)
+        return item.object
     else:
         raise ValueError(f"Item {item} is not a known item type.")
 
@@ -79,10 +76,12 @@ def item_to_object(item: Item) -> Any:
     "NumpyArrayItem",
     "PandasDataFrameItem",
     "PandasSeriesItem",
+    "PickleItem",
     "PolarsDataFrameItem",
     "PolarsSeriesItem",
     "PrimitiveItem",
     "SklearnBaseEstimatorItem",
     "SkrubTableReportItem",
+    "item_to_object",
     "object_to_item",
 ]
diff --git a/skore/src/skore/persistence/item/pickle_item.py b/skore/src/skore/persistence/item/pickle_item.py
new file mode 100644
index 000000000..ce9019488
--- /dev/null
+++ b/skore/src/skore/persistence/item/pickle_item.py
@@ -0,0 +1,25 @@
+from functools import cached_property
+from pickle import dumps, loads
+from typing import Any
+
+from skore.item.item import Item
+
+
+class PickleItem(Item):
+    def __init__(
+        self,
+        pickle_bytes: bytes,
+        created_at: str | None = None,
+        updated_at: str | None = None,
+    ):
+        super().__init__(created_at, updated_at)
+
+        self.pickle_bytes = pickle_bytes
+
+    @cached_property
+    def object(self) -> Any:
+        return loads(self.pickle_bytes)
+
+    @classmethod
+    def factory(cls, object: Any) -> PickleItem:
+        return cls(dumps(object))

From f4552e97f40e02af2adec7e3ec0a69eedd3c67c3 Mon Sep 17 00:00:00 2001
From: Thomas S <thomas@probabl.ai>
Date: Tue, 7 Jan 2025 16:52:33 +0100
Subject: [PATCH 05/22] [skip ci] Fix import of `SkrubTableReportItem`

---
 skore/src/skore/persistence/item/__init__.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/skore/src/skore/persistence/item/__init__.py b/skore/src/skore/persistence/item/__init__.py
index 57e3b4c10..770ce5979 100644
--- a/skore/src/skore/persistence/item/__init__.py
+++ b/skore/src/skore/persistence/item/__init__.py
@@ -5,6 +5,8 @@
 from contextlib import suppress
 from typing import Any
 
+import skrub_table_report_item as SkrubTableReportItem
+
 from .cross_validation_item import CrossValidationItem
 from .item import Item, ItemTypeError
 from .item_repository import ItemRepository
@@ -17,7 +19,6 @@
 from .polars_series_item import PolarsSeriesItem
 from .primitive_item import PrimitiveItem
 from .sklearn_base_estimator_item import SklearnBaseEstimatorItem
-from .skrub_table_report_item import SkrubTableReportItem
 
 
 def object_to_item(object: Any) -> Item:

From aff2a5f0c8db2edfa9cfcd58f7f7cb4d286ef425 Mon Sep 17 00:00:00 2001
From: Thomas S <thomas@probabl.ai>
Date: Wed, 8 Jan 2025 12:05:51 +0100
Subject: [PATCH 06/22] Fix imports and tests

Co-authored-by: Auguste Baum <auguste@probabl.ai>

commit 86281ca475f59c2fa43760b243c366c23c38b787
Author: Auguste Baum <auguste@probabl.ai>
Date:   Wed Jan 8 12:00:46 2025 +0100

    mob next [ci-skip] [ci skip] [skip ci]

    lastFile:skore/tests/integration/ui/test_ui.py

commit 9f6f1931584de22ab08a9e4a9779a5f17dee4501
Author: Thomas S <thomas@probabl.ai>
Date:   Wed Jan 8 11:52:12 2025 +0100

    mob next [ci-skip] [ci skip] [skip ci]

    lastFile:skore/tests/integration/ui/test_ui.py

commit cd385f66a805390893a6e415761ab1c0ea65550e
Author: Auguste Baum <auguste@probabl.ai>
Date:   Wed Jan 8 11:41:10 2025 +0100

    mob next [ci-skip] [ci skip] [skip ci]

    lastFile:skore/src/skore/persistence/item/sklearn_base_estimator_item.py

commit 41c53559266f139c785211fc97a43e1e2b281203
Author: Thomas S <thomas@probabl.ai>
Date:   Wed Jan 8 11:27:16 2025 +0100

    mob next [ci-skip] [ci skip] [skip ci]

    lastFile:skore/tests/integration/sklearn/test_cross_validate.py

commit a7d956edfeab6ef56020aaae8752e59f7f4e3491
Author: Auguste Baum <auguste@probabl.ai>
Date:   Wed Jan 8 11:14:59 2025 +0100

    mob next [ci-skip] [ci skip] [skip ci]

    lastFile:skore/tests/unit/view/test_view_repository.py

commit 38446cf8499b2d3bcf79d371b00e374a916dd77a
Author: Thomas S <thomas@probabl.ai>
Date:   Wed Jan 8 11:01:43 2025 +0100

    mob next [ci-skip] [ci skip] [skip ci]

    lastFile:skore/src/skore/persistence/item/pickle_item.py

commit a6e2a7914ada1e003c5295ccf233c73238972dfc
Author: Thomas S <thomas@probabl.ai>
Date:   Wed Jan 8 10:51:07 2025 +0100

    mob start [ci-skip] [ci skip] [skip ci]

Co-authored-by: Auguste Baum <auguste@probabl.ai>
---
 skore/src/skore/persistence/item/__init__.py  |  5 +-
 .../persistence/item/cross_validation_item.py |  3 +-
 .../src/skore/persistence/item/media_item.py  |  2 +-
 .../persistence/item/numpy_array_item.py      |  2 +-
 .../persistence/item/pandas_dataframe_item.py |  2 +-
 .../persistence/item/pandas_series_item.py    |  2 +-
 .../src/skore/persistence/item/pickle_item.py |  4 +-
 .../persistence/item/polars_dataframe_item.py |  2 +-
 .../persistence/item/polars_series_item.py    |  2 +-
 .../skore/persistence/item/primitive_item.py  |  2 +-
 .../item/sklearn_base_estimator_item.py       |  7 ++-
 .../item/skrub_table_report_item.py           |  4 +-
 .../skore/persistence/repository/__init__.py  |  7 +++
 .../persistence/repository/item_repository.py | 27 +++++-----
 .../src/skore/persistence/storage/__init__.py |  9 ++++
 skore/src/skore/project/create.py             |  2 +-
 skore/src/skore/project/load.py               |  8 +--
 skore/src/skore/project/project.py            |  7 ++-
 skore/src/skore/ui/project_routes.py          |  4 +-
 skore/tests/conftest.py                       |  5 +-
 .../sklearn/test_cross_validate.py            |  4 +-
 skore/tests/integration/ui/test_ui.py         | 51 ++++++++++++-------
 .../unit/item/test_cross_validation_item.py   |  8 +--
 skore/tests/unit/item/test_item_repository.py |  3 +-
 skore/tests/unit/item/test_media_item.py      |  4 +-
 .../tests/unit/item/test_numpy_array_item.py  |  4 +-
 .../unit/item/test_pandas_dataframe_item.py   |  4 +-
 .../unit/item/test_pandas_series_item.py      |  4 +-
 .../unit/item/test_polars_dataframe_item.py   |  6 +--
 .../unit/item/test_polars_series_item.py      |  4 +-
 skore/tests/unit/item/test_primitive_item.py  |  6 +--
 .../item/test_sklearn_base_estimator_item.py  |  4 +-
 .../unit/item/test_skrub_table_report_item.py |  4 +-
 skore/tests/unit/persistence/test_disk.py     |  2 +-
 skore/tests/unit/persistence/test_memory.py   |  2 +-
 skore/tests/unit/test_project.py              | 20 ++++----
 skore/tests/unit/view/test_view_repository.py |  6 +--
 37 files changed, 142 insertions(+), 100 deletions(-)
 create mode 100644 skore/src/skore/persistence/storage/__init__.py

diff --git a/skore/src/skore/persistence/item/__init__.py b/skore/src/skore/persistence/item/__init__.py
index 770ce5979..7b2d2f002 100644
--- a/skore/src/skore/persistence/item/__init__.py
+++ b/skore/src/skore/persistence/item/__init__.py
@@ -5,11 +5,9 @@
 from contextlib import suppress
 from typing import Any
 
-import skrub_table_report_item as SkrubTableReportItem
-
+from . import skrub_table_report_item as SkrubTableReportItem
 from .cross_validation_item import CrossValidationItem
 from .item import Item, ItemTypeError
-from .item_repository import ItemRepository
 from .media_item import MediaItem
 from .numpy_array_item import NumpyArrayItem
 from .pandas_dataframe_item import PandasDataFrameItem
@@ -72,7 +70,6 @@ def item_to_object(item: Item) -> Any:
 __all__ = [
     "CrossValidationItem",
     "Item",
-    "ItemRepository",
     "MediaItem",
     "NumpyArrayItem",
     "PandasDataFrameItem",
diff --git a/skore/src/skore/persistence/item/cross_validation_item.py b/skore/src/skore/persistence/item/cross_validation_item.py
index e4e4c4a2a..1121117be 100644
--- a/skore/src/skore/persistence/item/cross_validation_item.py
+++ b/skore/src/skore/persistence/item/cross_validation_item.py
@@ -20,9 +20,10 @@
 import plotly.graph_objects
 import plotly.io
 
-from skore.item.item import Item, ItemTypeError
 from skore.sklearn.cross_validation import CrossValidationReporter
 
+from .item import Item, ItemTypeError
+
 if TYPE_CHECKING:
     import sklearn.base
 
diff --git a/skore/src/skore/persistence/item/media_item.py b/skore/src/skore/persistence/item/media_item.py
index b83de93e4..b0c957bd6 100644
--- a/skore/src/skore/persistence/item/media_item.py
+++ b/skore/src/skore/persistence/item/media_item.py
@@ -9,7 +9,7 @@
 from io import BytesIO
 from typing import TYPE_CHECKING, Any
 
-from skore.item.item import Item, ItemTypeError
+from .item import Item, ItemTypeError
 
 if TYPE_CHECKING:
     from altair.vegalite.v5.schema.core import TopLevelSpec as Altair
diff --git a/skore/src/skore/persistence/item/numpy_array_item.py b/skore/src/skore/persistence/item/numpy_array_item.py
index 59d80bf66..5ebe0c82c 100644
--- a/skore/src/skore/persistence/item/numpy_array_item.py
+++ b/skore/src/skore/persistence/item/numpy_array_item.py
@@ -9,7 +9,7 @@
 from json import dumps, loads
 from typing import TYPE_CHECKING
 
-from skore.item.item import Item, ItemTypeError
+from .item import Item, ItemTypeError
 
 if TYPE_CHECKING:
     import numpy
diff --git a/skore/src/skore/persistence/item/pandas_dataframe_item.py b/skore/src/skore/persistence/item/pandas_dataframe_item.py
index f61fef26c..3d124677e 100644
--- a/skore/src/skore/persistence/item/pandas_dataframe_item.py
+++ b/skore/src/skore/persistence/item/pandas_dataframe_item.py
@@ -9,7 +9,7 @@
 from functools import cached_property
 from typing import TYPE_CHECKING
 
-from skore.item.item import Item, ItemTypeError
+from .item import Item, ItemTypeError
 
 if TYPE_CHECKING:
     import pandas
diff --git a/skore/src/skore/persistence/item/pandas_series_item.py b/skore/src/skore/persistence/item/pandas_series_item.py
index cd27ebea3..bfc52457c 100644
--- a/skore/src/skore/persistence/item/pandas_series_item.py
+++ b/skore/src/skore/persistence/item/pandas_series_item.py
@@ -9,7 +9,7 @@
 from functools import cached_property
 from typing import TYPE_CHECKING
 
-from skore.item.item import Item, ItemTypeError
+from .item import Item, ItemTypeError
 
 if TYPE_CHECKING:
     import pandas
diff --git a/skore/src/skore/persistence/item/pickle_item.py b/skore/src/skore/persistence/item/pickle_item.py
index ce9019488..42a0ace5d 100644
--- a/skore/src/skore/persistence/item/pickle_item.py
+++ b/skore/src/skore/persistence/item/pickle_item.py
@@ -1,8 +1,10 @@
+from __future__ import annotations
+
 from functools import cached_property
 from pickle import dumps, loads
 from typing import Any
 
-from skore.item.item import Item
+from .item import Item
 
 
 class PickleItem(Item):
diff --git a/skore/src/skore/persistence/item/polars_dataframe_item.py b/skore/src/skore/persistence/item/polars_dataframe_item.py
index d42292dbe..dc6b05533 100644
--- a/skore/src/skore/persistence/item/polars_dataframe_item.py
+++ b/skore/src/skore/persistence/item/polars_dataframe_item.py
@@ -9,7 +9,7 @@
 from functools import cached_property
 from typing import TYPE_CHECKING
 
-from skore.item.item import Item, ItemTypeError
+from .item import Item, ItemTypeError
 
 if TYPE_CHECKING:
     import polars
diff --git a/skore/src/skore/persistence/item/polars_series_item.py b/skore/src/skore/persistence/item/polars_series_item.py
index 7d846f9a9..ba0dd3f8c 100644
--- a/skore/src/skore/persistence/item/polars_series_item.py
+++ b/skore/src/skore/persistence/item/polars_series_item.py
@@ -9,7 +9,7 @@
 from functools import cached_property
 from typing import TYPE_CHECKING
 
-from skore.item.item import Item, ItemTypeError
+from .item import Item, ItemTypeError
 
 if TYPE_CHECKING:
     import polars
diff --git a/skore/src/skore/persistence/item/primitive_item.py b/skore/src/skore/persistence/item/primitive_item.py
index 3e7d1e1a5..039032312 100644
--- a/skore/src/skore/persistence/item/primitive_item.py
+++ b/skore/src/skore/persistence/item/primitive_item.py
@@ -7,7 +7,7 @@
 
 from typing import TYPE_CHECKING
 
-from skore.item.item import Item, ItemTypeError
+from .item import Item, ItemTypeError
 
 if TYPE_CHECKING:
     from typing import Union
diff --git a/skore/src/skore/persistence/item/sklearn_base_estimator_item.py b/skore/src/skore/persistence/item/sklearn_base_estimator_item.py
index d40b61bba..40321970e 100644
--- a/skore/src/skore/persistence/item/sklearn_base_estimator_item.py
+++ b/skore/src/skore/persistence/item/sklearn_base_estimator_item.py
@@ -9,7 +9,7 @@
 from functools import cached_property
 from typing import TYPE_CHECKING
 
-from skore.item.item import Item, ItemTypeError
+from .item import Item, ItemTypeError
 
 if TYPE_CHECKING:
     import sklearn.base
@@ -101,11 +101,14 @@ def factory(cls, estimator: sklearn.base.BaseEstimator) -> SklearnBaseEstimatorI
         """
         import sklearn.base
         import sklearn.utils
-        import skops.io
 
         if not isinstance(estimator, sklearn.base.BaseEstimator):
             raise ItemTypeError(f"Type '{estimator.__class__}' is not supported.")
 
+        # This line is only needed if we know `estimator` has the right type, so we do
+        # it after the type check
+        import skops.io
+
         estimator_html_repr = sklearn.utils.estimator_html_repr(estimator)
         estimator_skops = skops.io.dumps(estimator)
         estimator_skops_untrusted_types = skops.io.get_untrusted_types(
diff --git a/skore/src/skore/persistence/item/skrub_table_report_item.py b/skore/src/skore/persistence/item/skrub_table_report_item.py
index b411256f2..07eae5bbd 100644
--- a/skore/src/skore/persistence/item/skrub_table_report_item.py
+++ b/skore/src/skore/persistence/item/skrub_table_report_item.py
@@ -4,8 +4,8 @@
 
 from typing import TYPE_CHECKING
 
-from skore.item.item import ItemTypeError
-from skore.item.media_item import MediaItem
+from .item import ItemTypeError
+from .media_item import MediaItem
 
 if TYPE_CHECKING:
     from skrub import TableReport
diff --git a/skore/src/skore/persistence/repository/__init__.py b/skore/src/skore/persistence/repository/__init__.py
index e69de29bb..c088fdacf 100644
--- a/skore/src/skore/persistence/repository/__init__.py
+++ b/skore/src/skore/persistence/repository/__init__.py
@@ -0,0 +1,7 @@
+from .item_repository import ItemRepository
+from .view_repository import ViewRepository
+
+__all__ = [
+    "ItemRepository",
+    "ViewRepository",
+]
diff --git a/skore/src/skore/persistence/repository/item_repository.py b/skore/src/skore/persistence/repository/item_repository.py
index 74210964f..aea849f80 100644
--- a/skore/src/skore/persistence/repository/item_repository.py
+++ b/skore/src/skore/persistence/repository/item_repository.py
@@ -8,20 +8,21 @@
 
 from typing import TYPE_CHECKING
 
+from skore.persistence.item import (
+    CrossValidationItem,
+    MediaItem,
+    NumpyArrayItem,
+    PandasDataFrameItem,
+    PandasSeriesItem,
+    PolarsDataFrameItem,
+    PolarsSeriesItem,
+    PrimitiveItem,
+    SklearnBaseEstimatorItem,
+)
+
 if TYPE_CHECKING:
-    from skore.item.item import Item
-    from skore.persistence.abstract_storage import AbstractStorage
-
-
-from skore.item.cross_validation_item import CrossValidationItem
-from skore.item.media_item import MediaItem
-from skore.item.numpy_array_item import NumpyArrayItem
-from skore.item.pandas_dataframe_item import PandasDataFrameItem
-from skore.item.pandas_series_item import PandasSeriesItem
-from skore.item.polars_dataframe_item import PolarsDataFrameItem
-from skore.item.polars_series_item import PolarsSeriesItem
-from skore.item.primitive_item import PrimitiveItem
-from skore.item.sklearn_base_estimator_item import SklearnBaseEstimatorItem
+    from skore.persistence.item import Item
+    from skore.persistence.storage import AbstractStorage
 
 
 class ItemRepository:
diff --git a/skore/src/skore/persistence/storage/__init__.py b/skore/src/skore/persistence/storage/__init__.py
new file mode 100644
index 000000000..21b6a3b1a
--- /dev/null
+++ b/skore/src/skore/persistence/storage/__init__.py
@@ -0,0 +1,9 @@
+from .abstract_storage import AbstractStorage
+from .disk_cache_storage import DiskCacheStorage
+from .in_memory_storage import InMemoryStorage
+
+__all__ = [
+    "AbstractStorage",
+    "DiskCacheStorage",
+    "InMemoryStorage",
+]
diff --git a/skore/src/skore/project/create.py b/skore/src/skore/project/create.py
index bee8449d5..fcffce9d0 100644
--- a/skore/src/skore/project/create.py
+++ b/skore/src/skore/project/create.py
@@ -11,10 +11,10 @@
     ProjectCreationError,
     ProjectPermissionError,
 )
+from skore.persistence.view.view import View
 from skore.project.load import load
 from skore.project.project import Project, logger
 from skore.utils._logger import logger_context
-from skore.view.view import View
 
 
 def _validate_project_name(project_name: str) -> tuple[bool, Optional[Exception]]:
diff --git a/skore/src/skore/project/load.py b/skore/src/skore/project/load.py
index c78948690..0e8e7f064 100644
--- a/skore/src/skore/project/load.py
+++ b/skore/src/skore/project/load.py
@@ -3,10 +3,12 @@
 from pathlib import Path
 from typing import Union
 
-from skore.item import ItemRepository
-from skore.persistence.disk_cache_storage import DirectoryDoesNotExist, DiskCacheStorage
+from skore.persistence.repository import ItemRepository, ViewRepository
+from skore.persistence.storage.disk_cache_storage import (
+    DirectoryDoesNotExist,
+    DiskCacheStorage,
+)
 from skore.project.project import Project
-from skore.view.view_repository import ViewRepository
 
 
 class ProjectLoadError(Exception):
diff --git a/skore/src/skore/project/project.py b/skore/src/skore/project/project.py
index 299409425..3cca337f2 100644
--- a/skore/src/skore/project/project.py
+++ b/skore/src/skore/project/project.py
@@ -2,9 +2,10 @@
 
 from __future__ import annotations
 
+import logging
 from typing import TYPE_CHECKING, Any, Optional, Union
 
-from skore.persistence import item_to_object, object_to_item
+from skore.persistence.item import item_to_object, object_to_item
 
 if TYPE_CHECKING:
     from skore.persistence import (
@@ -15,6 +16,10 @@
     )
 
 
+logger = logging.getLogger(__name__)
+logger.addHandler(logging.NullHandler())  # Default to no output
+logger.setLevel(logging.INFO)
+
 MISSING = object()
 
 
diff --git a/skore/src/skore/ui/project_routes.py b/skore/src/skore/ui/project_routes.py
index 040e5dbca..79eff5ce6 100644
--- a/skore/src/skore/ui/project_routes.py
+++ b/skore/src/skore/ui/project_routes.py
@@ -9,9 +9,9 @@
 
 from fastapi import APIRouter, HTTPException, Request, status
 
-from skore.item import Item
+from skore.persistence.item import Item
+from skore.persistence.view.view import Layout, View
 from skore.project import Project
-from skore.view.view import Layout, View
 
 router = APIRouter(prefix="/project")
 
diff --git a/skore/tests/conftest.py b/skore/tests/conftest.py
index 6b2e3e0ad..61642fb5b 100644
--- a/skore/tests/conftest.py
+++ b/skore/tests/conftest.py
@@ -1,10 +1,9 @@
 from datetime import datetime, timezone
 
 import pytest
-from skore.item.item_repository import ItemRepository
-from skore.persistence.in_memory_storage import InMemoryStorage
+from skore.persistence.repository import ItemRepository, ViewRepository
+from skore.persistence.storage import InMemoryStorage
 from skore.project import Project
-from skore.view.view_repository import ViewRepository
 
 
 @pytest.fixture
diff --git a/skore/tests/integration/sklearn/test_cross_validate.py b/skore/tests/integration/sklearn/test_cross_validate.py
index 8c8992728..e39f6ba58 100644
--- a/skore/tests/integration/sklearn/test_cross_validate.py
+++ b/skore/tests/integration/sklearn/test_cross_validate.py
@@ -10,7 +10,7 @@
 from sklearn.multiclass import OneVsOneClassifier
 from sklearn.svm import SVC
 from skore import CrossValidationReporter
-from skore.item.cross_validation_item import CrossValidationItem
+from skore.persistence.item.cross_validation_item import CrossValidationItem
 from skore.sklearn.cross_validation.cross_validation_helpers import _get_scorers_to_add
 
 
@@ -200,7 +200,7 @@ def test_cross_validation_reporter(in_memory_project, fixture_name, request):
 
     in_memory_project.put("cross-validation", reporter)
 
-    retrieved_item = in_memory_project.get_item("cross-validation")
+    retrieved_item = in_memory_project.item_repository.get_item("cross-validation")
     assert isinstance(retrieved_item, CrossValidationItem)
 
 
diff --git a/skore/tests/integration/ui/test_ui.py b/skore/tests/integration/ui/test_ui.py
index f467ff699..f5f984e26 100644
--- a/skore/tests/integration/ui/test_ui.py
+++ b/skore/tests/integration/ui/test_ui.py
@@ -1,7 +1,9 @@
 import datetime
+import json
 
 import numpy
 import pandas
+import plotly
 import polars
 import pytest
 from fastapi.testclient import TestClient
@@ -9,9 +11,8 @@
 from sklearn.linear_model import Lasso
 from sklearn.model_selection import KFold
 from skore import CrossValidationReporter
-from skore.item.media_item import MediaItem
+from skore.persistence.view.view import View
 from skore.ui.app import create_app
-from skore.view.view import View
 
 
 @pytest.fixture
@@ -136,16 +137,12 @@ def test_serialize_media_item(client, in_memory_project):
 
     html = "<h1>éપUœALDXIWDŸΩΩ</h1>"
     in_memory_project.put("html", html)
-    in_memory_project.put_item(
-        "media html", MediaItem.factory_str(html, media_type="text/html")
-    )
 
     response = client.get("/api/project/items")
     assert response.status_code == 200
     project = response.json()
     assert "image" in project["items"]["img"][0]["media_type"]
     assert project["items"]["html"][0]["value"] == html
-    assert project["items"]["media html"][0]["value"] == html
 
 
 @pytest.fixture
@@ -178,9 +175,21 @@ def test_serialize_cross_validation_item(
     mock_nowstr,
     fake_cross_validate,
 ):
-    monkeypatch.setattr("skore.item.item.datetime", MockDatetime)
+    monkeypatch.setattr("skore.persistence.item.item.datetime", MockDatetime)
+    monkeypatch.setattr(
+        "skore.persistence.item.cross_validation_item.CrossValidationItem.plots", {}
+    )
+    monkeypatch.setattr(
+        "skore.sklearn.cross_validation.cross_validation_reporter.plot_cross_validation_compare_scores",
+        lambda _: {},
+    )
+    monkeypatch.setattr(
+        "skore.sklearn.cross_validation.cross_validation_reporter.plot_cross_validation_timing_normalized",
+        lambda _: {},
+    )
     monkeypatch.setattr(
-        "skore.item.cross_validation_item.CrossValidationItem.plots", {}
+        "skore.sklearn.cross_validation.cross_validation_reporter.plot_cross_validation_timing",
+        lambda _: {},
     )
 
     def prepare_cv():
@@ -196,17 +205,12 @@ def prepare_cv():
     reporter = CrossValidationReporter(model, X, y, cv=KFold(3))
     in_memory_project.put("cv", reporter)
 
-    # Mock the item to make the plot empty
-    item = in_memory_project.get_item("cv")
-    item.plots_bytes = {"compare_scores": b"{}"}
-    in_memory_project.put_item("cv_mocked", item)
-
     response = client.get("/api/project/items")
     assert response.status_code == 200
 
     project = response.json()
     expected = {
-        "name": "cv_mocked",
+        "name": "cv",
         "media_type": "application/vnd.skore.cross_validation+json",
         "value": {
             "scalar_results": [
@@ -227,7 +231,20 @@ def prepare_cv():
                     ],
                 }
             ],
-            "plots": [{"name": "compare_scores", "value": {}}],
+            "plots": [
+                {
+                    "name": "Scores",
+                    "value": json.loads(plotly.io.to_json({}, engine="json")),
+                },
+                {
+                    "name": "Timings",
+                    "value": json.loads(plotly.io.to_json({}, engine="json")),
+                },
+                {
+                    "name": "Normalized timings",
+                    "value": json.loads(plotly.io.to_json({}, engine="json")),
+                },
+            ],
             "sections": [
                 {
                     "title": "Model",
@@ -266,7 +283,7 @@ def prepare_cv():
         "updated_at": mock_nowstr,
         "created_at": mock_nowstr,
     }
-    actual = project["items"]["cv_mocked"][0]
+    actual = project["items"]["cv"][0]
     assert expected == actual
 
 
@@ -282,7 +299,7 @@ def now(*args, **kwargs):
             MockDatetime.NOW += MockDatetime.TIMEDELTA
             return MockDatetime.NOW
 
-    monkeypatch.setattr("skore.item.item.datetime", MockDatetime)
+    monkeypatch.setattr("skore.persistence.item.item.datetime", MockDatetime)
 
     for i in range(5):
         in_memory_project.put(str(i), i)
diff --git a/skore/tests/unit/item/test_cross_validation_item.py b/skore/tests/unit/item/test_cross_validation_item.py
index 6ee82a3a7..af691fc06 100644
--- a/skore/tests/unit/item/test_cross_validation_item.py
+++ b/skore/tests/unit/item/test_cross_validation_item.py
@@ -4,9 +4,9 @@
 import plotly.graph_objects
 import pytest
 from sklearn.model_selection import StratifiedKFold
-from skore.item.cross_validation_item import (
+from skore.persistence.item import ItemTypeError
+from skore.persistence.item.cross_validation_item import (
     CrossValidationItem,
-    ItemTypeError,
     _hash_numpy,
 )
 from skore.sklearn.cross_validation import CrossValidationReporter
@@ -67,7 +67,7 @@ class FakeCrossValidationReporterNoGetParams(CrossValidationReporter):
 class TestCrossValidationItem:
     @pytest.fixture(autouse=True)
     def monkeypatch_datetime(self, monkeypatch, MockDatetime):
-        monkeypatch.setattr("skore.item.item.datetime", MockDatetime)
+        monkeypatch.setattr("skore.persistence.item.item.datetime", MockDatetime)
 
     def test_factory_exception(self):
         with pytest.raises(ItemTypeError):
@@ -111,7 +111,7 @@ def test_factory(self, mock_nowstr, reporter):
 
     def test_get_serializable_dict(self, monkeypatch, mock_nowstr):
         monkeypatch.setattr(
-            "skore.item.cross_validation_item.CrossValidationReporter",
+            "skore.persistence.item.cross_validation_item.CrossValidationReporter",
             FakeCrossValidationReporter,
         )
 
diff --git a/skore/tests/unit/item/test_item_repository.py b/skore/tests/unit/item/test_item_repository.py
index 79b93548d..b2672bd30 100644
--- a/skore/tests/unit/item/test_item_repository.py
+++ b/skore/tests/unit/item/test_item_repository.py
@@ -1,7 +1,8 @@
 from datetime import datetime, timezone
 
 import pytest
-from skore.item import ItemRepository, MediaItem
+from skore.persistence.item import MediaItem
+from skore.persistence.repository import ItemRepository
 
 
 class TestItemRepository:
diff --git a/skore/tests/unit/item/test_media_item.py b/skore/tests/unit/item/test_media_item.py
index 97d4b579e..024f2fb5a 100644
--- a/skore/tests/unit/item/test_media_item.py
+++ b/skore/tests/unit/item/test_media_item.py
@@ -5,13 +5,13 @@
 import PIL as pillow
 import plotly.graph_objects as go
 import pytest
-from skore.item import ItemTypeError, MediaItem
+from skore.persistence.item import ItemTypeError, MediaItem
 
 
 class TestMediaItem:
     @pytest.fixture(autouse=True)
     def monkeypatch_datetime(self, monkeypatch, MockDatetime):
-        monkeypatch.setattr("skore.item.item.datetime", MockDatetime)
+        monkeypatch.setattr("skore.persistence.item.item.datetime", MockDatetime)
 
     def test_factory_exception(self):
         with pytest.raises(ItemTypeError):
diff --git a/skore/tests/unit/item/test_numpy_array_item.py b/skore/tests/unit/item/test_numpy_array_item.py
index a793cfed1..ed1c29317 100644
--- a/skore/tests/unit/item/test_numpy_array_item.py
+++ b/skore/tests/unit/item/test_numpy_array_item.py
@@ -2,13 +2,13 @@
 
 import numpy
 import pytest
-from skore.item import ItemTypeError, NumpyArrayItem
+from skore.persistence.item import ItemTypeError, NumpyArrayItem
 
 
 class TestNumpyArrayItem:
     @pytest.fixture(autouse=True)
     def monkeypatch_datetime(self, monkeypatch, MockDatetime):
-        monkeypatch.setattr("skore.item.item.datetime", MockDatetime)
+        monkeypatch.setattr("skore.persistence.item.item.datetime", MockDatetime)
 
     def test_factory_exception(self):
         with pytest.raises(ItemTypeError):
diff --git a/skore/tests/unit/item/test_pandas_dataframe_item.py b/skore/tests/unit/item/test_pandas_dataframe_item.py
index da9b8f80a..2b6b0edf9 100644
--- a/skore/tests/unit/item/test_pandas_dataframe_item.py
+++ b/skore/tests/unit/item/test_pandas_dataframe_item.py
@@ -2,13 +2,13 @@
 import pytest
 from pandas import DataFrame, Index, MultiIndex
 from pandas.testing import assert_frame_equal
-from skore.item import ItemTypeError, PandasDataFrameItem
+from skore.persistence.item import ItemTypeError, PandasDataFrameItem
 
 
 class TestPandasDataFrameItem:
     @pytest.fixture(autouse=True)
     def monkeypatch_datetime(self, monkeypatch, MockDatetime):
-        monkeypatch.setattr("skore.item.item.datetime", MockDatetime)
+        monkeypatch.setattr("skore.persistence.item.item.datetime", MockDatetime)
 
     def test_factory_exception(self):
         with pytest.raises(ItemTypeError):
diff --git a/skore/tests/unit/item/test_pandas_series_item.py b/skore/tests/unit/item/test_pandas_series_item.py
index eb160f765..4a2e396ac 100644
--- a/skore/tests/unit/item/test_pandas_series_item.py
+++ b/skore/tests/unit/item/test_pandas_series_item.py
@@ -2,13 +2,13 @@
 import pytest
 from pandas import Index, MultiIndex, Series
 from pandas.testing import assert_series_equal
-from skore.item import ItemTypeError, PandasSeriesItem
+from skore.persistence.item import ItemTypeError, PandasSeriesItem
 
 
 class TestPandasSeriesItem:
     @pytest.fixture(autouse=True)
     def monkeypatch_datetime(self, monkeypatch, MockDatetime):
-        monkeypatch.setattr("skore.item.item.datetime", MockDatetime)
+        monkeypatch.setattr("skore.persistence.item.item.datetime", MockDatetime)
 
     def test_factory_exception(self):
         with pytest.raises(ItemTypeError):
diff --git a/skore/tests/unit/item/test_polars_dataframe_item.py b/skore/tests/unit/item/test_polars_dataframe_item.py
index 8be5250fc..0335e7d06 100644
--- a/skore/tests/unit/item/test_polars_dataframe_item.py
+++ b/skore/tests/unit/item/test_polars_dataframe_item.py
@@ -2,14 +2,14 @@
 import pytest
 from polars import DataFrame
 from polars.testing import assert_frame_equal
-from skore.item import ItemTypeError, PolarsDataFrameItem
-from skore.item.polars_dataframe_item import PolarsToJSONError
+from skore.persistence.item import ItemTypeError, PolarsDataFrameItem
+from skore.persistence.item.polars_dataframe_item import PolarsToJSONError
 
 
 class TestPolarsDataFrameItem:
     @pytest.fixture(autouse=True)
     def monkeypatch_datetime(self, monkeypatch, MockDatetime):
-        monkeypatch.setattr("skore.item.item.datetime", MockDatetime)
+        monkeypatch.setattr("skore.persistence.item.item.datetime", MockDatetime)
 
     def test_factory_exception(self):
         with pytest.raises(ItemTypeError):
diff --git a/skore/tests/unit/item/test_polars_series_item.py b/skore/tests/unit/item/test_polars_series_item.py
index 8ca235c41..1e40a0c3f 100644
--- a/skore/tests/unit/item/test_polars_series_item.py
+++ b/skore/tests/unit/item/test_polars_series_item.py
@@ -2,13 +2,13 @@
 import pytest
 from polars import Series
 from polars.testing import assert_series_equal
-from skore.item import ItemTypeError, PolarsSeriesItem
+from skore.persistence.item import ItemTypeError, PolarsSeriesItem
 
 
 class TestPolarsSeriesItem:
     @pytest.fixture(autouse=True)
     def monkeypatch_datetime(self, monkeypatch, MockDatetime):
-        monkeypatch.setattr("skore.item.item.datetime", MockDatetime)
+        monkeypatch.setattr("skore.persistence.item.item.datetime", MockDatetime)
 
     def test_factory_exception(self):
         with pytest.raises(ItemTypeError):
diff --git a/skore/tests/unit/item/test_primitive_item.py b/skore/tests/unit/item/test_primitive_item.py
index 2a97f6eff..babcdf2b8 100644
--- a/skore/tests/unit/item/test_primitive_item.py
+++ b/skore/tests/unit/item/test_primitive_item.py
@@ -1,5 +1,5 @@
 import pytest
-from skore.item import ItemTypeError, PrimitiveItem
+from skore.persistence.item import ItemTypeError, PrimitiveItem
 
 
 class TestPrimitiveItem:
@@ -16,7 +16,7 @@ class TestPrimitiveItem:
         ],
     )
     def test_factory(self, monkeypatch, mock_nowstr, MockDatetime, primitive):
-        monkeypatch.setattr("skore.item.item.datetime", MockDatetime)
+        monkeypatch.setattr("skore.persistence.item.item.datetime", MockDatetime)
 
         item = PrimitiveItem.factory(primitive)
 
@@ -43,7 +43,7 @@ def test_factory_exception(self):
     def test_get_serializable_dict(
         self, monkeypatch, mock_nowstr, MockDatetime, primitive
     ):
-        monkeypatch.setattr("skore.item.item.datetime", MockDatetime)
+        monkeypatch.setattr("skore.persistence.item.item.datetime", MockDatetime)
 
         item = PrimitiveItem.factory(primitive)
         serializable = item.as_serializable_dict()
diff --git a/skore/tests/unit/item/test_sklearn_base_estimator_item.py b/skore/tests/unit/item/test_sklearn_base_estimator_item.py
index 469a705bc..d0cbe93cf 100644
--- a/skore/tests/unit/item/test_sklearn_base_estimator_item.py
+++ b/skore/tests/unit/item/test_sklearn_base_estimator_item.py
@@ -1,7 +1,7 @@
 import pytest
 import sklearn.svm
 import skops.io
-from skore.item import ItemTypeError, SklearnBaseEstimatorItem
+from skore.persistence.item import ItemTypeError, SklearnBaseEstimatorItem
 
 
 class Estimator(sklearn.svm.SVC):
@@ -11,7 +11,7 @@ class Estimator(sklearn.svm.SVC):
 class TestSklearnBaseEstimatorItem:
     @pytest.fixture(autouse=True)
     def monkeypatch_datetime(self, monkeypatch, MockDatetime):
-        monkeypatch.setattr("skore.item.item.datetime", MockDatetime)
+        monkeypatch.setattr("skore.persistence.item.item.datetime", MockDatetime)
 
     def test_factory_exception(self):
         with pytest.raises(ItemTypeError):
diff --git a/skore/tests/unit/item/test_skrub_table_report_item.py b/skore/tests/unit/item/test_skrub_table_report_item.py
index eef317096..d35236166 100644
--- a/skore/tests/unit/item/test_skrub_table_report_item.py
+++ b/skore/tests/unit/item/test_skrub_table_report_item.py
@@ -1,12 +1,12 @@
 import pytest
 from pandas import DataFrame
-from skore.item import ItemTypeError, SkrubTableReportItem
+from skore.persistence.item import ItemTypeError, SkrubTableReportItem
 from skrub import TableReport
 
 
 class TestSkrubTableReportItem:
     def test_factory(self, monkeypatch, mock_nowstr, MockDatetime):
-        monkeypatch.setattr("skore.item.item.datetime", MockDatetime)
+        monkeypatch.setattr("skore.persistence.item.item.datetime", MockDatetime)
         monkeypatch.setattr("secrets.token_hex", lambda: "azertyuiop")
 
         df = DataFrame(dict(a=[1, 2], b=["one", "two"], c=[11.1, 11.1]))
diff --git a/skore/tests/unit/persistence/test_disk.py b/skore/tests/unit/persistence/test_disk.py
index 77838978e..7c747c400 100644
--- a/skore/tests/unit/persistence/test_disk.py
+++ b/skore/tests/unit/persistence/test_disk.py
@@ -2,7 +2,7 @@
 import shutil
 from pathlib import Path
 
-from skore.persistence.disk_cache_storage import DiskCacheStorage
+from skore.persistence.storage import DiskCacheStorage
 
 
 def test_disk_storage(tmp_path: Path):
diff --git a/skore/tests/unit/persistence/test_memory.py b/skore/tests/unit/persistence/test_memory.py
index f28dcc73d..53608496e 100644
--- a/skore/tests/unit/persistence/test_memory.py
+++ b/skore/tests/unit/persistence/test_memory.py
@@ -1,4 +1,4 @@
-from skore.persistence.in_memory_storage import InMemoryStorage
+from skore.persistence.storage import InMemoryStorage
 
 
 def test_in_memory_storage():
diff --git a/skore/tests/unit/test_project.py b/skore/tests/unit/test_project.py
index 88b256e54..662ed5e90 100644
--- a/skore/tests/unit/test_project.py
+++ b/skore/tests/unit/test_project.py
@@ -17,6 +17,7 @@
     ProjectAlreadyExistsError,
     ProjectCreationError,
 )
+from skore.persistence.view.view import View
 from skore.project import (
     Project,
     create,
@@ -24,7 +25,6 @@
 )
 from skore.project.create import _validate_project_name
 from skore.project.load import ProjectLoadError
-from skore.view.view import View
 
 
 def test_put_string_item(in_memory_project):
@@ -262,17 +262,15 @@ def test_put_several_nested(in_memory_project):
     assert in_memory_project.get("a") == {"b": "baz"}
 
 
-def test_put_several_error(in_memory_project):
-    """If some key-value pairs are wrong, add all that are valid and print a warning."""
-    with pytest.raises(NotImplementedError):
-        in_memory_project.put(
-            {
-                "a": "foo",
-                "b": (lambda: "unsupported object"),
-            }
-        )
+def test_put_several_lambda(in_memory_project):
+    in_memory_project.put(
+        {
+            "a": "foo",
+            "b": (lambda: "unsupported object"),
+        }
+    )
 
-    assert in_memory_project.list_item_keys() == ["a"]
+    assert in_memory_project.list_item_keys() == ["a", "b"]
 
 
 def test_put_key_is_a_tuple(in_memory_project):
diff --git a/skore/tests/unit/view/test_view_repository.py b/skore/tests/unit/view/test_view_repository.py
index ed46d271d..87c21cea1 100644
--- a/skore/tests/unit/view/test_view_repository.py
+++ b/skore/tests/unit/view/test_view_repository.py
@@ -1,7 +1,7 @@
 import pytest
-from skore.persistence.in_memory_storage import InMemoryStorage
-from skore.view.view import View
-from skore.view.view_repository import ViewRepository
+from skore.persistence.repository import ViewRepository
+from skore.persistence.storage import InMemoryStorage
+from skore.persistence.view.view import View
 
 
 @pytest.fixture

From 9a3698ca002365d992b07fceb2129ccbdd29644d Mon Sep 17 00:00:00 2001
From: Thomas S <thomas@probabl.ai>
Date: Thu, 9 Jan 2025 10:48:45 +0100
Subject: [PATCH 07/22] Change the way a pickle item is exported to UI

---
 skore/src/skore/persistence/item/pickle_item.py | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/skore/src/skore/persistence/item/pickle_item.py b/skore/src/skore/persistence/item/pickle_item.py
index 42a0ace5d..2f6d8ff55 100644
--- a/skore/src/skore/persistence/item/pickle_item.py
+++ b/skore/src/skore/persistence/item/pickle_item.py
@@ -25,3 +25,9 @@ def object(self) -> Any:
     @classmethod
     def factory(cls, object: Any) -> PickleItem:
         return cls(dumps(object))
+
+    def as_serializable_dict(self):
+        return super().as_serializable_dict() | {
+            "media_type": "text/markdown",
+            "value": repr(self.object),
+        }

From 8643aa9b7d66e148441b235bb67f9ef4e7f40108 Mon Sep 17 00:00:00 2001
From: Thomas S <thomas@probabl.ai>
Date: Fri, 10 Jan 2025 11:30:09 +0100
Subject: [PATCH 08/22] Add tests

---
 skore/src/skore/persistence/item/__init__.py  |  6 +--
 .../persistence/repository/item_repository.py | 26 +-----------
 skore/tests/integration/ui/test_ui.py         | 29 ++++++++++++++
 skore/tests/unit/item/test_pickle_item.py     | 40 +++++++++++++++++++
 skore/tests/unit/project/test_project.py      |  9 +----
 5 files changed, 76 insertions(+), 34 deletions(-)
 create mode 100644 skore/tests/unit/item/test_pickle_item.py

diff --git a/skore/src/skore/persistence/item/__init__.py b/skore/src/skore/persistence/item/__init__.py
index 7b2d2f002..79b0eb138 100644
--- a/skore/src/skore/persistence/item/__init__.py
+++ b/skore/src/skore/persistence/item/__init__.py
@@ -43,7 +43,7 @@ def object_to_item(object: Any) -> Item:
             #     correct type. If not, they throw a ItemTypeError exception.
             return cls.factory(object)
 
-    return PickleItem(object)
+    return PickleItem.factory(object)
 
 
 def item_to_object(item: Item) -> Any:
@@ -51,9 +51,9 @@ def item_to_object(item: Item) -> Any:
         return item.primitive
     elif isinstance(item, NumpyArrayItem):
         return item.array
-    elif isinstance(item, PandasDataFrameItem) or isinstance(item, PolarsDataFrameItem):
+    elif isinstance(item, (PandasDataFrameItem, PolarsDataFrameItem)):
         return item.dataframe
-    elif isinstance(item, PandasSeriesItem) or isinstance(item, PolarsSeriesItem):
+    elif isinstance(item, (PandasSeriesItem, PolarsSeriesItem)):
         return item.series
     elif isinstance(item, SklearnBaseEstimatorItem):
         return item.estimator
diff --git a/skore/src/skore/persistence/repository/item_repository.py b/skore/src/skore/persistence/repository/item_repository.py
index aea849f80..dd99258ef 100644
--- a/skore/src/skore/persistence/repository/item_repository.py
+++ b/skore/src/skore/persistence/repository/item_repository.py
@@ -8,17 +8,7 @@
 
 from typing import TYPE_CHECKING
 
-from skore.persistence.item import (
-    CrossValidationItem,
-    MediaItem,
-    NumpyArrayItem,
-    PandasDataFrameItem,
-    PandasSeriesItem,
-    PolarsDataFrameItem,
-    PolarsSeriesItem,
-    PrimitiveItem,
-    SklearnBaseEstimatorItem,
-)
+import skore.persistence.item
 
 if TYPE_CHECKING:
     from skore.persistence.item import Item
@@ -35,18 +25,6 @@ class ItemRepository:
     storage as a map from keys to *lists of* values.
     """
 
-    ITEM_CLASS_NAME_TO_ITEM_CLASS = {
-        "MediaItem": MediaItem,
-        "NumpyArrayItem": NumpyArrayItem,
-        "PandasDataFrameItem": PandasDataFrameItem,
-        "PandasSeriesItem": PandasSeriesItem,
-        "PolarsDataFrameItem": PolarsDataFrameItem,
-        "PolarsSeriesItem": PolarsSeriesItem,
-        "PrimitiveItem": PrimitiveItem,
-        "CrossValidationItem": CrossValidationItem,
-        "SklearnBaseEstimatorItem": SklearnBaseEstimatorItem,
-    }
-
     def __init__(self, storage: AbstractStorage):
         """
         Initialize the ItemRepository with a storage system.
@@ -68,7 +46,7 @@ def __deconstruct_item(item: Item) -> dict:
     @staticmethod
     def __construct_item(value) -> Item:
         item_class_name = value["item_class_name"]
-        item_class = ItemRepository.ITEM_CLASS_NAME_TO_ITEM_CLASS[item_class_name]
+        item_class = getattr(skore.persistence.item, item_class_name)
         item = value["item"]
 
         return item_class(**item)
diff --git a/skore/tests/integration/ui/test_ui.py b/skore/tests/integration/ui/test_ui.py
index a4d641ee7..360761a6f 100644
--- a/skore/tests/integration/ui/test_ui.py
+++ b/skore/tests/integration/ui/test_ui.py
@@ -337,3 +337,32 @@ def now(*args, **kwargs):
         ("5", 5),
         ("4", 5),
     ]
+
+
+def test_get_items_with_pickle_item(
+    monkeypatch,
+    MockDatetime,
+    mock_nowstr,
+    client,
+    in_memory_project,
+):
+    monkeypatch.setattr("skore.persistence.item.item.datetime", MockDatetime)
+    in_memory_project.put("pickle", object)
+
+    response = client.get("/api/project/items")
+
+    assert response.status_code == 200
+    assert response.json() == {
+        "items": {
+            "pickle": [
+                {
+                    "created_at": mock_nowstr,
+                    "updated_at": mock_nowstr,
+                    "name": "pickle",
+                    "media_type": "text/markdown",
+                    "value": "<class 'object'>",
+                },
+            ],
+        },
+        "views": {},
+    }
diff --git a/skore/tests/unit/item/test_pickle_item.py b/skore/tests/unit/item/test_pickle_item.py
new file mode 100644
index 000000000..acbc3924e
--- /dev/null
+++ b/skore/tests/unit/item/test_pickle_item.py
@@ -0,0 +1,40 @@
+import pickle
+
+import pytest
+from skore.persistence.item import PickleItem
+
+
+class TestPickleItem:
+    @pytest.fixture(autouse=True)
+    def monkeypatch_datetime(self, monkeypatch, MockDatetime):
+        monkeypatch.setattr("skore.persistence.item.item.datetime", MockDatetime)
+
+    @pytest.mark.parametrize("object", [0, 0.0, int, True, [0], {0: 0}])
+    def test_factory(self, mock_nowstr, object):
+        item = PickleItem.factory(object)
+
+        assert item.pickle_bytes == pickle.dumps(object)
+        assert item.created_at == mock_nowstr
+        assert item.updated_at == mock_nowstr
+
+    def test_object(self, mock_nowstr):
+        item1 = PickleItem.factory(int)
+        item2 = PickleItem(
+            pickle_bytes=pickle.dumps(int),
+            created_at=mock_nowstr,
+            updated_at=mock_nowstr,
+        )
+
+        assert item1.object is int
+        assert item2.object is int
+
+    def test_get_serializable_dict(self, mock_nowstr):
+        item = PickleItem.factory(int)
+        serializable = item.as_serializable_dict()
+
+        assert serializable == {
+            "updated_at": mock_nowstr,
+            "created_at": mock_nowstr,
+            "media_type": "text/markdown",
+            "value": repr(int),
+        }
diff --git a/skore/tests/unit/project/test_project.py b/skore/tests/unit/project/test_project.py
index a1da72d71..13414b7e5 100644
--- a/skore/tests/unit/project/test_project.py
+++ b/skore/tests/unit/project/test_project.py
@@ -235,13 +235,8 @@ def test_put_several_nested(in_memory_project):
     assert in_memory_project.get("a") == {"b": "baz"}
 
 
-def test_put_several_lambda(in_memory_project):
-    in_memory_project.put(
-        {
-            "a": "foo",
-            "b": (lambda: "unsupported object"),
-        }
-    )
+def test_put_several_complex(in_memory_project):
+    in_memory_project.put({"a": int, "b": float})
 
     assert in_memory_project.list_item_keys() == ["a", "b"]
 

From 80df8dbdf67fc488d7c90ca5ea2c0702ca535cda Mon Sep 17 00:00:00 2001
From: Thomas S <thomas@probabl.ai>
Date: Fri, 10 Jan 2025 15:05:48 +0100
Subject: [PATCH 09/22] Add docstring

---
 skore/src/skore/persistence/item/__init__.py  |  1 +
 .../src/skore/persistence/item/pickle_item.py | 41 +++++++++++++++++++
 .../skore/persistence/repository/__init__.py  |  2 +
 .../src/skore/persistence/storage/__init__.py |  2 +
 4 files changed, 46 insertions(+)

diff --git a/skore/src/skore/persistence/item/__init__.py b/skore/src/skore/persistence/item/__init__.py
index 79b0eb138..fca1e5c18 100644
--- a/skore/src/skore/persistence/item/__init__.py
+++ b/skore/src/skore/persistence/item/__init__.py
@@ -47,6 +47,7 @@ def object_to_item(object: Any) -> Item:
 
 
 def item_to_object(item: Item) -> Any:
+    """Transform an Item into its original object."""
     if isinstance(item, PrimitiveItem):
         return item.primitive
     elif isinstance(item, NumpyArrayItem):
diff --git a/skore/src/skore/persistence/item/pickle_item.py b/skore/src/skore/persistence/item/pickle_item.py
index 2f6d8ff55..30c627cde 100644
--- a/skore/src/skore/persistence/item/pickle_item.py
+++ b/skore/src/skore/persistence/item/pickle_item.py
@@ -1,3 +1,9 @@
+"""PickleItem.
+
+This module defines the PickleItem class, which is used to persist objects that cannot
+be otherwise.
+"""
+
 from __future__ import annotations
 
 from functools import cached_property
@@ -8,25 +14,60 @@
 
 
 class PickleItem(Item):
+    """
+    A class to represent any object item.
+
+    This class is generally used to persist objects that cannot be otherwise.
+    It encapsulates the object with its pickle representaton, its creation and update
+    timestamps.
+    """
+
     def __init__(
         self,
         pickle_bytes: bytes,
         created_at: str | None = None,
         updated_at: str | None = None,
     ):
+        """
+        Initialize a PickleItem.
+
+        Parameters
+        ----------
+        pickle_bytes : bytes
+            The raw bytes of the object pickle representation.
+        created_at : str
+            The creation timestamp in ISO format.
+        updated_at : str
+            The last update timestamp in ISO format.
+        """
         super().__init__(created_at, updated_at)
 
         self.pickle_bytes = pickle_bytes
 
     @cached_property
     def object(self) -> Any:
+        """The object from the persistence."""
         return loads(self.pickle_bytes)
 
     @classmethod
     def factory(cls, object: Any) -> PickleItem:
+        """
+        Create a new PickleItem with any object.
+
+        Parameters
+        ----------
+        object: Any
+            The object to store.
+
+        Returns
+        -------
+        PickleItem
+            A new PickleItem instance.
+        """
         return cls(dumps(object))
 
     def as_serializable_dict(self):
+        """Get a JSON serializable representation of the item."""
         return super().as_serializable_dict() | {
             "media_type": "text/markdown",
             "value": repr(self.object),
diff --git a/skore/src/skore/persistence/repository/__init__.py b/skore/src/skore/persistence/repository/__init__.py
index c088fdacf..845bb362c 100644
--- a/skore/src/skore/persistence/repository/__init__.py
+++ b/skore/src/skore/persistence/repository/__init__.py
@@ -1,3 +1,5 @@
+"""Provide a set of classes responsible for manipulating items and views."""
+
 from .item_repository import ItemRepository
 from .view_repository import ViewRepository
 
diff --git a/skore/src/skore/persistence/storage/__init__.py b/skore/src/skore/persistence/storage/__init__.py
index 21b6a3b1a..75bb67428 100644
--- a/skore/src/skore/persistence/storage/__init__.py
+++ b/skore/src/skore/persistence/storage/__init__.py
@@ -1,3 +1,5 @@
+"""Provide a set of storage classes for storing and retrieving data."""
+
 from .abstract_storage import AbstractStorage
 from .disk_cache_storage import DiskCacheStorage
 from .in_memory_storage import InMemoryStorage

From c8f3ecfa0b5dd7f26bf4e72954d61be319bf83e7 Mon Sep 17 00:00:00 2001
From: Thomas S <thomas@probabl.ai>
Date: Fri, 10 Jan 2025 17:29:32 +0100
Subject: [PATCH 10/22] WIP - Change examples

---
 .../getting_started/plot_tracking_items.py     |  2 +-
 .../plot_working_with_projects.py              | 18 ++++++------------
 .../model_evaluation/plot_cross_validate.py    |  2 +-
 3 files changed, 8 insertions(+), 14 deletions(-)

diff --git a/examples/getting_started/plot_tracking_items.py b/examples/getting_started/plot_tracking_items.py
index 11bfe30aa..ec8e1a5fb 100644
--- a/examples/getting_started/plot_tracking_items.py
+++ b/examples/getting_started/plot_tracking_items.py
@@ -73,7 +73,7 @@
 # We retrieve the history of the ``my_int`` item:
 
 # %%
-item_histories = my_project.get_item_versions("my_int")
+item_histories = my_project.get_item_versions("my_int")  # TO CHANGE /!\
 
 # %%
 # We can print the first history (first iteration) of this item:
diff --git a/examples/getting_started/plot_working_with_projects.py b/examples/getting_started/plot_working_with_projects.py
index 0b16b2074..3d672df1d 100644
--- a/examples/getting_started/plot_working_with_projects.py
+++ b/examples/getting_started/plot_working_with_projects.py
@@ -119,25 +119,19 @@ def my_func(x):
 )
 
 # %%
-# Moreover, we can also explicitly tell skore the media type of an object, for example
-# in HTML:
+# Moreover, we can also explicitly tell skore the way we want to display an object, for
+# example in HTML:
 
 # %%
-from skore.item import MediaItem
 
-my_project.put_item(
+my_project.put(
     "my_string_3",
-    MediaItem.factory(
-        "<p><h1>Title</h1> <b>bold</b>, <i>italic</i>, etc.</p>", media_type="text/html"
-    ),
+    "<p><h1>Title</h1> <b>bold</b>, <i>italic</i>, etc.</p>",
+    display_as="html",
 )
 
 # %%
-# .. note::
-#   We used :func:`~skore.Project.put_item` instead of :func:`~skore.Project.put`.
-
-# %%
-# Note that the media type is only used for the UI, and not in this notebook at hand:
+# Note that the `display_as` is only used for the UI, and not in this notebook at hand:
 
 # %%
 my_project.get("my_string_3")
diff --git a/examples/model_evaluation/plot_cross_validate.py b/examples/model_evaluation/plot_cross_validate.py
index 9422e37b0..a47b6b74f 100644
--- a/examples/model_evaluation/plot_cross_validate.py
+++ b/examples/model_evaluation/plot_cross_validate.py
@@ -157,7 +157,7 @@
 # %%
 # We can also access the plot after we have stored the ``CrossValidationReporter``:
 my_project.put("cross_validation_regression", reporter)
-cv_item = my_project.get_item("cross_validation_regression")
+cv_item = my_project.get_item("cross_validation_regression")  # TO CHANGE /!\
 cv_item.plots["Scores"]
 
 # %%

From c4b2ee8cdac0bdf69ef814bd5fef4e3cf23b1c85 Mon Sep 17 00:00:00 2001
From: Thomas S <thomas@probabl.ai>
Date: Mon, 13 Jan 2025 16:22:18 +0100
Subject: [PATCH 11/22] Rename CrossValidationItem to
 CrossValidationReporterItem

---
 skore/src/skore/persistence/item/__init__.py           | 10 +++++-----
 ...ation_item.py => cross_validation_reporter_item.py} |  0
 2 files changed, 5 insertions(+), 5 deletions(-)
 rename skore/src/skore/persistence/item/{cross_validation_item.py => cross_validation_reporter_item.py} (100%)

diff --git a/skore/src/skore/persistence/item/__init__.py b/skore/src/skore/persistence/item/__init__.py
index fca1e5c18..bc3890ce5 100644
--- a/skore/src/skore/persistence/item/__init__.py
+++ b/skore/src/skore/persistence/item/__init__.py
@@ -6,7 +6,7 @@
 from typing import Any
 
 from . import skrub_table_report_item as SkrubTableReportItem
-from .cross_validation_item import CrossValidationItem
+from .cross_validation_reporter_item import CrossValidationReporterItem
 from .item import Item, ItemTypeError
 from .media_item import MediaItem
 from .numpy_array_item import NumpyArrayItem
@@ -31,7 +31,7 @@ def object_to_item(object: Any) -> Item:
         SklearnBaseEstimatorItem,
         MediaItem,
         SkrubTableReportItem,
-        CrossValidationItem,
+        CrossValidationReporterItem,
     ):
         with suppress(ImportError, ItemTypeError):
             # ImportError:
@@ -58,8 +58,8 @@ def item_to_object(item: Item) -> Any:
         return item.series
     elif isinstance(item, SklearnBaseEstimatorItem):
         return item.estimator
-    elif isinstance(item, CrossValidationItem):
-        return item.cv_results_serialized
+    elif isinstance(item, CrossValidationReporterItem):
+        return item.reporter
     elif isinstance(item, MediaItem):
         return item.media_bytes
     elif isinstance(item, PickleItem):
@@ -69,7 +69,7 @@ def item_to_object(item: Item) -> Any:
 
 
 __all__ = [
-    "CrossValidationItem",
+    "CrossValidationReporterItem",
     "Item",
     "MediaItem",
     "NumpyArrayItem",
diff --git a/skore/src/skore/persistence/item/cross_validation_item.py b/skore/src/skore/persistence/item/cross_validation_reporter_item.py
similarity index 100%
rename from skore/src/skore/persistence/item/cross_validation_item.py
rename to skore/src/skore/persistence/item/cross_validation_reporter_item.py

From 4d08a193321bbaa1e9d7a31e7868a76cbd24df5d Mon Sep 17 00:00:00 2001
From: Thomas S <thomas@probabl.ai>
Date: Mon, 13 Jan 2025 17:06:18 +0100
Subject: [PATCH 12/22] CrossValidationReporterItem's factory now pickles the
 reporter

---
 .../item/cross_validation_reporter_item.py    | 369 +++++++-----------
 .../sklearn/test_cross_validate.py            |   4 +-
 skore/tests/integration/ui/test_ui.py         |   5 +-
 ...=> test_cross_validation_reporter_item.py} |  58 ++-
 4 files changed, 172 insertions(+), 264 deletions(-)
 rename skore/tests/unit/item/{test_cross_validation_item.py => test_cross_validation_reporter_item.py} (80%)

diff --git a/skore/src/skore/persistence/item/cross_validation_reporter_item.py b/skore/src/skore/persistence/item/cross_validation_reporter_item.py
index 23c81dab9..263e1528c 100644
--- a/skore/src/skore/persistence/item/cross_validation_reporter_item.py
+++ b/skore/src/skore/persistence/item/cross_validation_reporter_item.py
@@ -1,20 +1,21 @@
-"""CrossValidationItem class.
+"""CrossValidationReporterItem.
 
-This class represents the output of a cross-validation workflow.
+This module defines the CrossValidationReporterItem class, which is used to persist
+reporters of cross-validation.
 """
 
 from __future__ import annotations
 
 import contextlib
-import copy
 import dataclasses
 import hashlib
 import importlib
 import json
+import pickle
 import re
 import statistics
 from functools import cached_property
-from typing import TYPE_CHECKING, Any, Literal, TypedDict, Union
+from typing import TYPE_CHECKING, Literal, Optional, TypedDict
 
 import numpy
 import plotly.graph_objects
@@ -27,8 +28,6 @@
 if TYPE_CHECKING:
     import sklearn.base
 
-    CVSplitter = Any
-
     class EstimatorParamInfo(TypedDict):
         """Information about an estimator parameter."""
 
@@ -43,6 +42,12 @@ class EstimatorInfo(TypedDict):
         params: dict[str, EstimatorParamInfo]
 
 
+HUMANIZED_PLOT_NAMES = {
+    "scores": "Scores",
+    "timing": "Timings",
+}
+
+
 def _hash_numpy(arr: numpy.ndarray) -> str:
     """Compute a hash string from a numpy array.
 
@@ -117,86 +122,122 @@ def _params_to_str(estimator_info) -> str:
     return "\n".join(params_list)
 
 
-# Data used for training, passed as input to scikit-learn
-Data = Any
-# Target used for training, passed as input to scikit-learn
-Target = Any
+def _estimator_info(estimator: sklearn.base.BaseEstimator) -> EstimatorInfo:
+    estimator_params = (
+        estimator.get_params() if hasattr(estimator, "get_params") else {}
+    )
+
+    name = estimator.__class__.__name__
+    module = estimator.__module__
+
+    # Figure out the default parameters of the estimator,
+    # so that we can highlight the non-default ones in the UI
+
+    # This is done by instantiating the class with no arguments and
+    # computing the diff between the default and ours
+    try:
+        estimator_module = importlib.import_module(module)
+        EstimatorClass = getattr(estimator_module, name)
+        default_estimator_params = EstimatorClass().get_params()
+    except Exception:
+        default_estimator_params = {}
+
+    final_estimator_params: dict[str, EstimatorParamInfo] = {}
+    for k, v in estimator_params.items():
+        param_is_default: bool = (
+            k in default_estimator_params and default_estimator_params[k] == v
+        )
+        final_estimator_params[str(k)] = {
+            "value": repr(v),
+            "default": param_is_default,
+        }
 
+    return {
+        "name": name,
+        "module": module,
+        "params": final_estimator_params,
+    }
 
-class CrossValidationItem(Item):
-    """
-    A class to represent the output of a cross-validation workflow.
 
-    This class encapsulates the output of the
-    :func:`sklearn.model_selection.cross_validate` function along with its creation and
-    update timestamps.
-    """
+class CrossValidationReporterItem(Item):
+    """Class to persist the reporter of cross-validation."""
 
     def __init__(
         self,
-        cv_results_serialized: dict,
-        estimator_info: EstimatorInfo,
-        X_info: dict,
-        y_info: Union[dict, None],
-        plots_bytes: dict[str, bytes],
-        cv_info: dict,
-        created_at: Union[str, None] = None,
-        updated_at: Union[str, None] = None,
+        reporter_bytes: bytes,
+        created_at: Optional[str] = None,
+        updated_at: Optional[str] = None,
     ):
         """
-        Initialize a CrossValidationItem.
+        Initialize a CrossValidationReporterItem.
 
         Parameters
         ----------
-        cv_results_serialized : dict
-            The dict output of the :func:`sklearn.model_selection.cross_validate`
-            function, in a form suitable for serialization.
-        estimator_info : dict
-            The estimator that was cross-validated.
-        X_info : dict
-            A summary of the data, input of the
-            :func:`sklearn.model_selection.cross_validate` function.
-        y_info : dict
-            A summary of the target, input of the
-            :func:`sklearn.model_selection.cross_validate` function.
-        plots_bytes : dict[str, bytes]
-            A collection of plots of the cross-validation results, in the form of bytes.
-        cv_info: dict
-            A dict containing cross validation splitting strategy params.
-        created_at : str
+        reporter_bytes : bytes
+            The raw bytes of the reporter pickle representation.
+        created_at : str, optional
             The creation timestamp in ISO format.
-        updated_at : str
+        updated_at : str, optional
             The last update timestamp in ISO format.
         """
         super().__init__(created_at, updated_at)
 
-        self.cv_results_serialized = cv_results_serialized
-        self.estimator_info = estimator_info
-        self.X_info = X_info
-        self.y_info = y_info
-        self.plots_bytes = plots_bytes
-        self.cv_info = cv_info
+        self.reporter_bytes = reporter_bytes
 
-    def as_serializable_dict(self):
-        """Get a serializable dict from the item.
+    @classmethod
+    def factory(cls, reporter: CrossValidationReporter) -> CrossValidationReporterItem:
+        """
+        Create a CrossValidationReporterItem instance from a CrossValidationReporter.
 
-        Derived class must call their super implementation
-        and merge the result with their output.
+        Parameters
+        ----------
+        reporter : CrossValidationReporter
+
+        Returns
+        -------
+        CrossValidationReporterItem
+            A new CrossValidationReporterItem instance.
         """
+        if not isinstance(reporter, CrossValidationReporter):
+            raise ItemTypeError(f"Type '{reporter.__class__}' is not supported.")
+
+        instance = cls(pickle.dumps(reporter))
+
+        # add reporter as cached property
+        instance.reporter = reporter
+
+        return instance
+
+    @cached_property
+    def reporter(self) -> CrossValidationReporter:
+        """The CrossValidationReporter from the persistence."""
+        return pickle.loads(self.reporter_bytes)
+
+    def as_serializable_dict(self):
+        """Get a serializable dict from the item."""
         # Get tabular results (the cv results in a dataframe-like structure)
-        cv_results = copy.deepcopy(self.cv_results_serialized)
-        cv_results.pop("indices", None)
-
-        metrics_names = list(cv_results.keys())
-        tabular_results = {
-            "name": "Cross validation results",
-            "columns": metrics_names,
-            "data": list(zip(*cv_results.values())),
-            "favorability": [_metric_favorability(m) for m in metrics_names],
+        cv_results = {
+            key: value.tolist()
+            for key, value in self.reporter.cv_results.items()
+            if (
+                key != "estimator"
+                and key != "indices"
+                and isinstance(value, numpy.ndarray)
+            )
         }
 
+        metrics_names = list(cv_results)
+        tabular_results = [
+            {
+                "name": "Cross validation results",
+                "columns": metrics_names,
+                "data": list(zip(*cv_results.values())),
+                "favorability": [_metric_favorability(m) for m in metrics_names],
+            }
+        ]
+
         # Get scalar results (summary statistics of the cv results)
-        mean_cv_results = [
+        scalar_results = [
             {
                 "name": _metric_title(k),
                 "value": statistics.mean(v),
@@ -206,163 +247,22 @@ def as_serializable_dict(self):
             for k, v in cv_results.items()
         ]
 
-        scalar_results = mean_cv_results
-
-        params_as_str = _params_to_str(self.estimator_info)
-
         # If the estimator is from sklearn, make the class name a hyperlink
         # to the relevant docs
-        name = self.estimator_info["name"]
-        module = re.sub(r"\.\_.+", "", self.estimator_info["module"])
+        estimator_info = _estimator_info(self.reporter.estimator)
+        name = estimator_info["name"]
+        module = re.sub(r"\.\_.+", "", estimator_info["module"])
         if module.startswith("sklearn"):
             doc_url = f"https://scikit-learn.org/stable/modules/generated/{module}.{name}.html"
             doc_link = f'<a href="{doc_url}" target="_blank"><code>{name}</code></a>'
         else:
             doc_link = f"`{name}`"
 
+        params_as_str = _params_to_str(estimator_info)
         estimator_params_as_str = f"{doc_link}\n{params_as_str}"
 
-        # Get cross-validation details
-        cv_params_as_str = ", ".join(f"{k}: *{v}*" for k, v in self.cv_info.items())
-
-        r = super().as_serializable_dict()
-        sections = [
-            {
-                "title": "Model",
-                "icon": "icon-square-cursor",
-                "items": [
-                    {
-                        "name": "Estimator parameters",
-                        "description": "Core model configuration used for training",
-                        "value": estimator_params_as_str,
-                    },
-                    {
-                        "name": "Cross-validation parameters",
-                        "description": "Controls how data is split and validated",
-                        "value": cv_params_as_str,
-                    },
-                ],
-            }
-        ]
-        value = {
-            "scalar_results": scalar_results,
-            "tabular_results": [tabular_results],
-            "plots": [
-                {
-                    "name": plot_name,
-                    "value": json.loads(plot_bytes.decode("utf-8")),
-                }
-                for plot_name, plot_bytes in self.plots_bytes.items()
-            ],
-            "sections": sections,
-        }
-        r.update(
-            {
-                "media_type": "application/vnd.skore.cross_validation+json",
-                "value": value,
-            }
-        )
-        return r
-
-    @staticmethod
-    def _estimator_info(estimator: sklearn.base.BaseEstimator) -> EstimatorInfo:
-        estimator_params = (
-            estimator.get_params() if hasattr(estimator, "get_params") else {}
-        )
-
-        name = estimator.__class__.__name__
-        module = estimator.__module__
-
-        # Figure out the default parameters of the estimator,
-        # so that we can highlight the non-default ones in the UI
-
-        # This is done by instantiating the class with no arguments and
-        # computing the diff between the default and ours
-        try:
-            estimator_module = importlib.import_module(module)
-            EstimatorClass = getattr(estimator_module, name)
-            default_estimator_params = EstimatorClass().get_params()
-        except Exception:
-            default_estimator_params = {}
-
-        final_estimator_params: dict[str, EstimatorParamInfo] = {}
-        for k, v in estimator_params.items():
-            param_is_default: bool = (
-                k in default_estimator_params and default_estimator_params[k] == v
-            )
-            final_estimator_params[str(k)] = {
-                "value": repr(v),
-                "default": param_is_default,
-            }
-
-        return {
-            "name": name,
-            "module": module,
-            "params": final_estimator_params,
-        }
-
-    @classmethod
-    def factory(cls, reporter: CrossValidationReporter) -> CrossValidationItem:
-        """
-        Create a new CrossValidationItem instance from a CrossValidationReporter.
-
-        Parameters
-        ----------
-        reporter : CrossValidationReporter
-
-        Returns
-        -------
-        CrossValidationItem
-            A new CrossValidationItem instance.
-        """
-        if not isinstance(reporter, CrossValidationReporter):
-            raise ItemTypeError(
-                f"Type '{reporter.__class__}' is not supported, "
-                f"only '{CrossValidationReporter.__name__}' is."
-            )
-
-        cv_results = reporter._cv_results
-        estimator = reporter.estimator
-        X = reporter.X
-        y = reporter.y
-        plots = reporter.plots
-        cv = reporter.cv
-
-        cv_results_serialized = {}
-        for k, v in cv_results.items():
-            if k == "estimator":
-                continue
-            if k == "indices":
-                cv_results_serialized["indices"] = {
-                    "train": tuple(arr.tolist() for arr in v["train"]),
-                    "test": tuple(arr.tolist() for arr in v["test"]),
-                }
-            if isinstance(v, numpy.ndarray):
-                cv_results_serialized[k] = v.tolist()
-
-        estimator_info = CrossValidationItem._estimator_info(estimator)
-
-        y_array = y if isinstance(y, numpy.ndarray) else numpy.array(y)
-        y_info = None if y is None else {"hash": _hash_numpy(y_array)}
-
-        X_array = X if isinstance(X, numpy.ndarray) else numpy.array(X)
-        X_info = {
-            "nb_rows": X_array.shape[0],
-            "nb_cols": X_array.shape[1],
-            "hash": _hash_numpy(X_array),
-        }
-
-        humanized_plot_names = {
-            "scores": "Scores",
-            "timing": "Timings",
-        }
-        plots_bytes = {
-            humanized_plot_names[plot_name]: (
-                plotly.io.to_json(plot, engine="json").encode("utf-8")
-            )
-            for plot_name, plot in dataclasses.asdict(plots).items()
-        }
-
+        #
+        cv = self.reporter.cv
         cv_info: dict[str, str] = {}
         if isinstance(cv, int):
             cv_info["n_splits"] = repr(cv)
@@ -376,19 +276,40 @@ def factory(cls, reporter: CrossValidationReporter) -> CrossValidationItem:
                     attr = getattr(cv, attr_name)
                     cv_info[attr_name] = repr(attr)
 
-        return cls(
-            cv_results_serialized=cv_results_serialized,
-            estimator_info=estimator_info,
-            X_info=X_info,
-            y_info=y_info,
-            plots_bytes=plots_bytes,
-            cv_info=cv_info,
-        )
+        cv_params_as_str = ", ".join(f"{k}: *{v}*" for k, v in cv_info.items())
 
-    @cached_property
-    def plots(self) -> dict:
-        """Various plots of the cross-validation results."""
-        return {
-            name: plotly.io.from_json(plot_bytes.decode("utf-8"))
-            for name, plot_bytes in self.plots_bytes.items()
+        #
+        value = {
+            "scalar_results": scalar_results,
+            "tabular_results": tabular_results,
+            "plots": [
+                {
+                    "name": HUMANIZED_PLOT_NAMES[plot_name],
+                    "value": json.loads(plotly.io.to_json(plot, engine="json")),
+                }
+                for plot_name, plot in dataclasses.asdict(self.reporter.plots).items()
+            ],
+            "sections": [
+                {
+                    "title": "Model",
+                    "icon": "icon-square-cursor",
+                    "items": [
+                        {
+                            "name": "Estimator parameters",
+                            "description": "Core model configuration used for training",
+                            "value": estimator_params_as_str,
+                        },
+                        {
+                            "name": "Cross-validation parameters",
+                            "description": "Controls how data is split and validated",
+                            "value": cv_params_as_str,
+                        },
+                    ],
+                }
+            ],
+        }
+
+        return super().as_serializable_dict() | {
+            "media_type": "application/vnd.skore.cross_validation+json",
+            "value": value,
         }
diff --git a/skore/tests/integration/sklearn/test_cross_validate.py b/skore/tests/integration/sklearn/test_cross_validate.py
index e39f6ba58..00758f751 100644
--- a/skore/tests/integration/sklearn/test_cross_validate.py
+++ b/skore/tests/integration/sklearn/test_cross_validate.py
@@ -10,7 +10,7 @@
 from sklearn.multiclass import OneVsOneClassifier
 from sklearn.svm import SVC
 from skore import CrossValidationReporter
-from skore.persistence.item.cross_validation_item import CrossValidationItem
+from skore.persistence.item import CrossValidationReporterItem
 from skore.sklearn.cross_validation.cross_validation_helpers import _get_scorers_to_add
 
 
@@ -201,7 +201,7 @@ def test_cross_validation_reporter(in_memory_project, fixture_name, request):
     in_memory_project.put("cross-validation", reporter)
 
     retrieved_item = in_memory_project.item_repository.get_item("cross-validation")
-    assert isinstance(retrieved_item, CrossValidationItem)
+    assert isinstance(retrieved_item, CrossValidationReporterItem)
 
 
 @pytest.mark.parametrize(
diff --git a/skore/tests/integration/ui/test_ui.py b/skore/tests/integration/ui/test_ui.py
index 360761a6f..44b15d7a3 100644
--- a/skore/tests/integration/ui/test_ui.py
+++ b/skore/tests/integration/ui/test_ui.py
@@ -167,7 +167,7 @@ def _fake_cross_validate(*args, **kwargs):
     monkeypatch.setattr("sklearn.model_selection.cross_validate", _fake_cross_validate)
 
 
-def test_serialize_cross_validation_item(
+def test_serialize_cross_validation_reporter_item(
     client,
     in_memory_project,
     monkeypatch,
@@ -176,9 +176,6 @@ def test_serialize_cross_validation_item(
     fake_cross_validate,
 ):
     monkeypatch.setattr("skore.persistence.item.item.datetime", MockDatetime)
-    monkeypatch.setattr(
-        "skore.persistence.item.cross_validation_item.CrossValidationItem.plots", {}
-    )
     monkeypatch.setattr(
         "skore.sklearn.cross_validation.cross_validation_reporter.plot_cross_validation_compare_scores",
         lambda _: {},
diff --git a/skore/tests/unit/item/test_cross_validation_item.py b/skore/tests/unit/item/test_cross_validation_reporter_item.py
similarity index 80%
rename from skore/tests/unit/item/test_cross_validation_item.py
rename to skore/tests/unit/item/test_cross_validation_reporter_item.py
index 909eff872..973fc933d 100644
--- a/skore/tests/unit/item/test_cross_validation_item.py
+++ b/skore/tests/unit/item/test_cross_validation_reporter_item.py
@@ -1,13 +1,13 @@
 from dataclasses import dataclass
+from pickle import dumps
 
 import numpy
 import plotly.graph_objects
 import pytest
 from sklearn.model_selection import StratifiedKFold
 from skore.persistence.item import ItemTypeError
-from skore.persistence.item.cross_validation_item import (
-    CrossValidationItem,
-    _hash_numpy,
+from skore.persistence.item.cross_validation_reporter_item import (
+    CrossValidationReporterItem,
     _metric_favorability,
 )
 from skore.sklearn.cross_validation import CrossValidationReporter
@@ -27,7 +27,7 @@ class FakeEstimatorNoGetParams:
 
 @dataclass
 class FakeCrossValidationReporter(CrossValidationReporter):
-    _cv_results = {
+    cv_results = {
         "test_score": numpy.array([1, 2, 3]),
         "estimator": [FakeEstimator(), FakeEstimator(), FakeEstimator()],
         "fit_time": [1, 2, 3],
@@ -44,7 +44,7 @@ class FakeCrossValidationReporter(CrossValidationReporter):
 
 @dataclass
 class FakeCrossValidationReporterNoGetParams(CrossValidationReporter):
-    _cv_results = {
+    cv_results = {
         "test_score": numpy.array([1, 2, 3]),
         "estimator": [
             FakeEstimatorNoGetParams(),
@@ -63,14 +63,14 @@ class FakeCrossValidationReporterNoGetParams(CrossValidationReporter):
     cv = StratifiedKFold(n_splits=5)
 
 
-class TestCrossValidationItem:
+class TestCrossValidationReporterItem:
     @pytest.fixture(autouse=True)
     def monkeypatch_datetime(self, monkeypatch, MockDatetime):
         monkeypatch.setattr("skore.persistence.item.item.datetime", MockDatetime)
 
     def test_factory_exception(self):
         with pytest.raises(ItemTypeError):
-            CrossValidationItem.factory(None)
+            CrossValidationReporterItem.factory(None)
 
     @pytest.mark.parametrize(
         "reporter",
@@ -82,42 +82,32 @@ def test_factory_exception(self):
         ],
     )
     def test_factory(self, mock_nowstr, reporter):
-        item = CrossValidationItem.factory(reporter)
-
-        assert item.cv_results_serialized == {"test_score": [1, 2, 3]}
-        assert item.estimator_info == {
-            "name": reporter.estimator.__class__.__name__,
-            "params": (
-                {}
-                if isinstance(reporter.estimator, FakeEstimatorNoGetParams)
-                else {"alpha": {"value": "3", "default": True}}
-            ),
-            "module": "tests.unit.item.test_cross_validation_item",
-        }
-        assert item.X_info == {
-            "nb_cols": 1,
-            "nb_rows": 1,
-            "hash": _hash_numpy(FakeCrossValidationReporter.X),
-        }
-        assert item.y_info == {"hash": _hash_numpy(FakeCrossValidationReporter.y)}
-        assert item.cv_info == {
-            "n_splits": "5",
-            "random_state": "None",
-            "shuffle": "False",
-        }
-        assert isinstance(item.plots_bytes, dict)
-        assert isinstance(item.plots, dict)
+        item = CrossValidationReporterItem.factory(reporter)
+
+        assert item.reporter_bytes == dumps(reporter)
         assert item.created_at == mock_nowstr
         assert item.updated_at == mock_nowstr
 
+    def test_reporter(self, mock_nowstr):
+        reporter = FakeCrossValidationReporter()
+        item1 = CrossValidationReporterItem.factory(reporter)
+        item2 = CrossValidationReporterItem(
+            reporter_bytes=dumps(reporter),
+            created_at=mock_nowstr,
+            updated_at=mock_nowstr,
+        )
+
+        assert item1.reporter == reporter
+        assert item2.reporter == reporter
+
     def test_get_serializable_dict(self, monkeypatch, mock_nowstr):
         monkeypatch.setattr(
-            "skore.persistence.item.cross_validation_item.CrossValidationReporter",
+            "skore.persistence.item.cross_validation_reporter_item.CrossValidationReporter",
             FakeCrossValidationReporter,
         )
 
         reporter = FakeCrossValidationReporter()
-        item = CrossValidationItem.factory(reporter)
+        item = CrossValidationReporterItem.factory(reporter)
         serializable = item.as_serializable_dict()
 
         assert serializable["updated_at"] == mock_nowstr

From 43a296bd956d5841695bb6293f39f21f45a45e8a Mon Sep 17 00:00:00 2001
From: Thomas S <thomas@probabl.ai>
Date: Tue, 14 Jan 2025 15:34:55 +0100
Subject: [PATCH 13/22] [skip ci] Use `reporter._cv_results` instead of
 `reporter.cv_results`

---
 .../persistence/item/cross_validation_reporter_item.py    | 8 ++------
 .../unit/item/test_cross_validation_reporter_item.py      | 4 ++--
 2 files changed, 4 insertions(+), 8 deletions(-)

diff --git a/skore/src/skore/persistence/item/cross_validation_reporter_item.py b/skore/src/skore/persistence/item/cross_validation_reporter_item.py
index 263e1528c..258a30be2 100644
--- a/skore/src/skore/persistence/item/cross_validation_reporter_item.py
+++ b/skore/src/skore/persistence/item/cross_validation_reporter_item.py
@@ -218,12 +218,8 @@ def as_serializable_dict(self):
         # Get tabular results (the cv results in a dataframe-like structure)
         cv_results = {
             key: value.tolist()
-            for key, value in self.reporter.cv_results.items()
-            if (
-                key != "estimator"
-                and key != "indices"
-                and isinstance(value, numpy.ndarray)
-            )
+            for key, value in self.reporter._cv_results.items()
+            if key not in ("estimator", "indices") and isinstance(value, numpy.ndarray)
         }
 
         metrics_names = list(cv_results)
diff --git a/skore/tests/unit/item/test_cross_validation_reporter_item.py b/skore/tests/unit/item/test_cross_validation_reporter_item.py
index 973fc933d..0979d5fc3 100644
--- a/skore/tests/unit/item/test_cross_validation_reporter_item.py
+++ b/skore/tests/unit/item/test_cross_validation_reporter_item.py
@@ -27,7 +27,7 @@ class FakeEstimatorNoGetParams:
 
 @dataclass
 class FakeCrossValidationReporter(CrossValidationReporter):
-    cv_results = {
+    _cv_results = {
         "test_score": numpy.array([1, 2, 3]),
         "estimator": [FakeEstimator(), FakeEstimator(), FakeEstimator()],
         "fit_time": [1, 2, 3],
@@ -44,7 +44,7 @@ class FakeCrossValidationReporter(CrossValidationReporter):
 
 @dataclass
 class FakeCrossValidationReporterNoGetParams(CrossValidationReporter):
-    cv_results = {
+    _cv_results = {
         "test_score": numpy.array([1, 2, 3]),
         "estimator": [
             FakeEstimatorNoGetParams(),

From 459e5488917bd833bce32c76bf78abbb3432d4f7 Mon Sep 17 00:00:00 2001
From: Thomas S <thomas@probabl.ai>
Date: Tue, 14 Jan 2025 17:45:21 +0100
Subject: [PATCH 14/22] Add `display_as` parameter

---
 skore/src/skore/persistence/item/__init__.py  | 79 +++++++++++++------
 .../src/skore/persistence/item/media_item.py  | 11 ++-
 skore/src/skore/project/project.py            | 32 +++++---
 skore/tests/unit/project/test_display_as.py   | 35 ++++++++
 4 files changed, 120 insertions(+), 37 deletions(-)
 create mode 100644 skore/tests/unit/project/test_display_as.py

diff --git a/skore/src/skore/persistence/item/__init__.py b/skore/src/skore/persistence/item/__init__.py
index bc3890ce5..aa9ea9319 100644
--- a/skore/src/skore/persistence/item/__init__.py
+++ b/skore/src/skore/persistence/item/__init__.py
@@ -3,12 +3,12 @@
 from __future__ import annotations
 
 from contextlib import suppress
-from typing import Any
+from typing import Any, Literal, Optional
 
 from . import skrub_table_report_item as SkrubTableReportItem
 from .cross_validation_reporter_item import CrossValidationReporterItem
 from .item import Item, ItemTypeError
-from .media_item import MediaItem
+from .media_item import MediaItem, MediaType
 from .numpy_array_item import NumpyArrayItem
 from .pandas_dataframe_item import PandasDataFrameItem
 from .pandas_series_item import PandasSeriesItem
@@ -19,31 +19,60 @@
 from .sklearn_base_estimator_item import SklearnBaseEstimatorItem
 
 
-def object_to_item(object: Any) -> Item:
+def object_to_item(
+    object: Any,
+    /,
+    *,
+    note: Optional[str] = None,
+    display_as: Optional[Literal["HTML", "MARKDOWN", "SVG"]] = None,
+) -> Item:
     """Transform an object into an Item."""
-    for cls in (
-        PrimitiveItem,
-        PandasDataFrameItem,
-        PandasSeriesItem,
-        PolarsDataFrameItem,
-        PolarsSeriesItem,
-        NumpyArrayItem,
-        SklearnBaseEstimatorItem,
-        MediaItem,
-        SkrubTableReportItem,
-        CrossValidationReporterItem,
-    ):
-        with suppress(ImportError, ItemTypeError):
-            # ImportError:
-            #     The factories are responsible to import third-party libraries in a
-            #     lazy way. If library is missing, an ImportError exception will
-            #     automatically be thrown.
-            # ItemTypeError:
-            #     The factories are responsible for checking that parameters are of the
-            #     correct type. If not, they throw a ItemTypeError exception.
-            return cls.factory(object)
+    if display_as is not None:
+        if not isinstance(object, str):
+            raise TypeError("`object` must be a str if `display_as` is specified")
 
-    return PickleItem.factory(object)
+        if display_as not in MediaType.__members__:
+            raise ValueError(f"`display_as` must be in {list(MediaType.__members__)}")
+
+        item = MediaItem.factory_str(
+            media=object,
+            media_type=MediaType[display_as].value,
+        )
+    else:
+        for cls in (
+            PrimitiveItem,
+            PandasDataFrameItem,
+            PandasSeriesItem,
+            PolarsDataFrameItem,
+            PolarsSeriesItem,
+            NumpyArrayItem,
+            SklearnBaseEstimatorItem,
+            MediaItem,
+            SkrubTableReportItem,
+            CrossValidationReporterItem,
+        ):
+            with suppress(ImportError, ItemTypeError):
+                # ImportError:
+                #     The factories are responsible to import third-party libraries in a
+                #     lazy way. If library is missing, an ImportError exception will
+                #     automatically be thrown.
+                # ItemTypeError:
+                #     The factories are responsible for checking that parameters are of
+                #     the correct type. If not, they throw a ItemTypeError exception.
+                item = cls.factory(object)
+                break
+        else:
+            item = PickleItem.factory(object)
+
+    if not isinstance(note, (type(None), str)):
+        raise TypeError(f"`note` must be a string (found '{type(note)}')")
+
+    # Since the item classes are now private, and to avoid having to pass the `note`
+    # parameter in the factories of each item class, we define the content of the
+    # `note` attribute dynamically.
+    item.note = note
+
+    return item
 
 
 def item_to_object(item: Item) -> Any:
diff --git a/skore/src/skore/persistence/item/media_item.py b/skore/src/skore/persistence/item/media_item.py
index 3736a2345..e57434743 100644
--- a/skore/src/skore/persistence/item/media_item.py
+++ b/skore/src/skore/persistence/item/media_item.py
@@ -6,6 +6,7 @@
 from __future__ import annotations
 
 import base64
+from enum import Enum
 from io import BytesIO
 from typing import TYPE_CHECKING, Any, Union
 
@@ -25,6 +26,14 @@ def lazy_is_instance(object: Any, cls_fullname: str) -> bool:
     }
 
 
+class MediaType(Enum):
+    """Enum used to map aliases and media types."""
+
+    HTML = "text/html"
+    MARKDOWN = "text/markdown"
+    SVG = "image/svg+xml"
+
+
 class MediaItem(Item):
     """
     A class to represent a media item.
@@ -165,7 +174,7 @@ def factory_str(cls, media: str, media_type: str = "text/markdown") -> MediaItem
         media : str
             The string content to store.
         media_type : str, optional
-            The MIME type of the media content, by default "text/html".
+            The MIME type of the media content, by default "text/markdown".
 
         Returns
         -------
diff --git a/skore/src/skore/project/project.py b/skore/src/skore/project/project.py
index cb335feb5..365a7c97e 100644
--- a/skore/src/skore/project/project.py
+++ b/skore/src/skore/project/project.py
@@ -3,7 +3,7 @@
 from __future__ import annotations
 
 import logging
-from typing import TYPE_CHECKING, Any, Optional, Union
+from typing import TYPE_CHECKING, Any, Literal, Optional, Union
 
 from skore.persistence.item import item_to_object, object_to_item
 
@@ -73,7 +73,14 @@ def __init__(
         self.item_repository = item_repository
         self.view_repository = view_repository
 
-    def put(self, key: str, value: Any, *, note: Optional[str] = None):
+    def put(
+        self,
+        key: str,
+        value: Any,
+        *,
+        note: Optional[str] = None,
+        display_as: Optional[Literal["HTML", "MARKDOWN", "SVG"]] = None,
+    ):
         """Add a key-value pair to the Project.
 
         If an item with the same key already exists, its value is replaced by the new
@@ -85,8 +92,11 @@ def put(self, key: str, value: Any, *, note: Optional[str] = None):
             The key to associate with ``value`` in the Project.
         value : Any
             The value to associate with ``key`` in the Project.
-        note : str or None, optional
+        note : str, optional
             A note to attach with the item.
+        display_as : str, optional
+            Used in combination with a string value, it customizes the way the value is
+            displayed in the interface.
 
         Raises
         ------
@@ -99,14 +109,14 @@ def put(self, key: str, value: Any, *, note: Optional[str] = None):
         if not isinstance(key, str):
             raise TypeError(f"Key must be a string (found '{type(key)}')")
 
-        item = object_to_item(value)
-
-        if note is not None:
-            if not isinstance(note, str):
-                raise TypeError(f"Note must be a string (found '{type(note)}')")
-            item.note = note
-
-        self.item_repository.put_item(key, item)
+        self.item_repository.put_item(
+            key,
+            object_to_item(
+                value,
+                note=note,
+                display_as=display_as,
+            ),
+        )
 
     def get(self, key: str) -> Any:
         """Get the value corresponding to ``key`` from the Project.
diff --git a/skore/tests/unit/project/test_display_as.py b/skore/tests/unit/project/test_display_as.py
new file mode 100644
index 000000000..50833bc5a
--- /dev/null
+++ b/skore/tests/unit/project/test_display_as.py
@@ -0,0 +1,35 @@
+import pytest
+from skore.persistence.item import MediaItem, PrimitiveItem
+
+
+@pytest.fixture(autouse=True)
+def monkeypatch_datetime(monkeypatch, MockDatetime):
+    monkeypatch.setattr("skore.persistence.item.item.datetime", MockDatetime)
+
+
+def test_str_without_display_as(in_memory_project, mock_nowstr):
+    in_memory_project.put("key", "<str>")
+
+    item = in_memory_project.item_repository.get_item("key")
+
+    assert isinstance(item, PrimitiveItem)
+    assert item.primitive == "<str>"
+
+
+def test_str_with_display_as(in_memory_project, mock_nowstr):
+    in_memory_project.put("key", "<str>", display_as="MARKDOWN")
+
+    item = in_memory_project.item_repository.get_item("key")
+
+    assert isinstance(item, MediaItem)
+    assert item.media_bytes == b"<str>"
+    assert item.media_encoding == "utf-8"
+    assert item.media_type == "text/markdown"
+
+
+def test_exception(in_memory_project, mock_nowstr):
+    with pytest.raises(TypeError):
+        in_memory_project.put("key", 1, display_as="MARKDOWN")
+
+    with pytest.raises(ValueError):
+        in_memory_project.put("key", "<str>", display_as="<display_as>")

From daebfe6b1f590d5f580f2e2fcb7ab678a6bedc30 Mon Sep 17 00:00:00 2001
From: Thomas S <thomas@probabl.ai>
Date: Wed, 15 Jan 2025 10:22:25 +0100
Subject: [PATCH 15/22] Update examples

---
 examples/model_evaluation/plot_cross_validate.py | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/examples/model_evaluation/plot_cross_validate.py b/examples/model_evaluation/plot_cross_validate.py
index a47b6b74f..cb0ab5e3c 100644
--- a/examples/model_evaluation/plot_cross_validate.py
+++ b/examples/model_evaluation/plot_cross_validate.py
@@ -155,15 +155,16 @@
 reporter.plots.scores
 
 # %%
-# We can also access the plot after we have stored the ``CrossValidationReporter``:
-my_project.put("cross_validation_regression", reporter)
-cv_item = my_project.get_item("cross_validation_regression")  # TO CHANGE /!\
-cv_item.plots["Scores"]
+# We can put the reporter in the project, and retrieve it as is:
+my_project.put("cross_validation_reporter", reporter)
+
+reporter = my_project.get("cross_validation_reporter")
+reporter.plots.scores
 
 # %%
 # .. note::
 #
-#   If we put a cross-validation item in a skore project, we get some nice
+#   If we put a cross-validation reporter in a skore project, we get some nice
 #   information in the UI:
 #
 #   .. image:: https://media.githubusercontent.com/media/probabl-ai/skore/main/sphinx/_static/images/2024_12_12_skore_demo_comp.gif

From 3084bb039ca17d92f24b7ad32c23543181b1ff60 Mon Sep 17 00:00:00 2001
From: Thomas S <thomas@probabl.ai>
Date: Wed, 15 Jan 2025 12:48:59 +0100
Subject: [PATCH 16/22] [skip ci] refactorize `get_item_versions` to be item
 agnostic

---
 .../getting_started/plot_tracking_items.py    | 23 +++----
 skore/src/skore/project/project.py            | 67 ++++++++++---------
 skore/src/skore/ui/project_routes.py          | 13 ++--
 skore/tests/integration/ui/test_ui.py         |  2 +-
 skore/tests/unit/project/test_project.py      | 65 +++++++++++-------
 5 files changed, 93 insertions(+), 77 deletions(-)

diff --git a/examples/getting_started/plot_tracking_items.py b/examples/getting_started/plot_tracking_items.py
index ec8e1a5fb..9eefc83e2 100644
--- a/examples/getting_started/plot_tracking_items.py
+++ b/examples/getting_started/plot_tracking_items.py
@@ -73,17 +73,14 @@
 # We retrieve the history of the ``my_int`` item:
 
 # %%
-item_histories = my_project.get_item_versions("my_int")  # TO CHANGE /!\
+history = my_project.get("my_int", latest=False, metadata=True)
 
 # %%
 # We can print the first history (first iteration) of this item:
 
 # %%
-passed_item = item_histories[0]
-print(passed_item)
-print(passed_item.primitive)
-print(passed_item.created_at)
-print(passed_item.updated_at)
+
+print(history[0])
 
 # %%
 # Let us construct a dataframe with the values and last updated times:
@@ -92,13 +89,13 @@
 import numpy as np
 import pandas as pd
 
-list_primitive, list_created_at, list_updated_at = zip(
-    *[(elem.primitive, elem.created_at, elem.updated_at) for elem in item_histories]
+list_value, list_created_at, list_updated_at = zip(
+    *[(version["value"], history[0]["date"], version["date"]) for version in history]
 )
 
 df_track = pd.DataFrame(
     {
-        "primitive": list_primitive,
+        "value": list_value,
         "created_at": list_created_at,
         "updated_at": list_updated_at,
     }
@@ -111,9 +108,9 @@
 #   :language: python
 #
 # Notice that the ``created_at`` dates are the same for all iterations because they
-# correspond to the same item, but the ``updated_at`` dates are spaced by 0.1 second
-# (approximately) as we used :python:`time.sleep(0.1)` between each
-# :func:`~skore.Project.put`.
+# correspond to the date of the first version of the item, but the ``updated_at`` dates
+# are spaced by 0.1 second (approximately) as we used :python:`time.sleep(0.1)` between
+# each :func:`~skore.Project.put`.
 
 # %%
 # We can now track the value of the item over time:
@@ -124,7 +121,7 @@
 fig = px.line(
     df_track,
     x="iteration_number",
-    y="primitive",
+    y="value",
     hover_data=df_track.columns,
     markers=True,
 )
diff --git a/skore/src/skore/project/project.py b/skore/src/skore/project/project.py
index 365a7c97e..6271d8785 100644
--- a/skore/src/skore/project/project.py
+++ b/skore/src/skore/project/project.py
@@ -9,7 +9,6 @@
 
 if TYPE_CHECKING:
     from skore.persistence import (
-        Item,
         ItemRepository,
         View,
         ViewRepository,
@@ -118,55 +117,57 @@ def put(
             ),
         )
 
-    def get(self, key: str) -> Any:
-        """Get the value corresponding to ``key`` from the Project.
-
-        Parameters
-        ----------
-        key : str
-            The key corresponding to the item to get.
-
-        Raises
-        ------
-        KeyError
-            If the key does not correspond to any item.
-        """
-        return item_to_object(self.item_repository.get_item(key))
-
-    def get_item_versions(self, key: str) -> list[Item]:
-        """
-        Get all the versions of an item associated with ``key`` from the Project.
-
-        The list is ordered from oldest to newest :func:`~skore.Project.put` date.
+    def get(self, key, *, latest=True, metadata=False):
+        """Get the value associated to ``key`` from the Project.
 
         Parameters
         ----------
         key : str
             The key corresponding to the item to get.
+        latest : boolean, optional
+            Get the latest value or all the values associated to ``key``, default True.
+        metadata : boolean, optional
+            Get the metadata in addition of the value, default False.
 
         Returns
         -------
-        list[Item]
-            The list of items corresponding to ``key``.
+        value : any
+            Value associated to ``key``, when latest=True and metadata=False.
+        value_and_metadata : dict
+            Value associated to ``key`` with its metadata, when latest=True and metadata=True.
+        list_of_values : list[any]
+            Values associated to ``key``, ordered by date, when latest=False.
+        list_of_values_and_metadata : list[dict]
+            Values associated to ``key`` with their metadata, ordered by date, when
+            latest=False and metadata=False.
 
         Raises
         ------
         KeyError
-            If the key does not correspond to any item.
+            If the key is not in the project.
         """
-        return self.item_repository.get_item_versions(key)
+        if not metadata:
 
-    def list_item_keys(self) -> list[str]:
-        """List all item keys in the Project.
+            def dto(item):
+                return item_to_object(item)
 
-        Returns
-        -------
-        list[str]
-            The list of item keys. The list is empty if there is no item.
-        """
+        else:
+
+            def dto(item):
+                return {
+                    "value": item_to_object(item),
+                    "date": item.updated_at,
+                    "note": item.note,
+                }
+
+        if latest:
+            return dto(self.item_repository.get_item(key))
+        return list(map(dto, self.item_repository.get_item_versions(key)))
+
+    def keys(self) -> list[str]:
         return self.item_repository.keys()
 
-    def delete_item(self, key: str):
+    def delete(self, key: str):
         """Delete the item corresponding to ``key`` from the Project.
 
         Parameters
diff --git a/skore/src/skore/ui/project_routes.py b/skore/src/skore/ui/project_routes.py
index 79eff5ce6..e3ac728cb 100644
--- a/skore/src/skore/ui/project_routes.py
+++ b/skore/src/skore/ui/project_routes.py
@@ -49,12 +49,15 @@ def __item_as_serializable(name: str, item: Item) -> SerializableItem:
 def __project_as_serializable(project: Project) -> SerializableProject:
     items = {
         key: [
-            __item_as_serializable(key, item) for item in project.get_item_versions(key)
+            __item_as_serializable(key, item)
+            for item in project.item_repository.get_item_versions(key)
         ]
-        for key in project.list_item_keys()
+        for key in project.item_repository.keys()
     }
 
-    views = {key: project.get_view(key).layout for key in project.list_view_keys()}
+    views = {
+        key: project.get_view(key).layout for key in project.view_repository.keys()
+    }
 
     return SerializableProject(
         items=items,
@@ -112,8 +115,8 @@ async def get_activity(
     return sorted(
         (
             __item_as_serializable(key, version)
-            for key in project.list_item_keys()
-            for version in project.get_item_versions(key)
+            for key in project.item_repository.keys()
+            for version in project.item_repository.get_item_versions(key)
             if datetime.fromisoformat(version.updated_at) > after
         ),
         key=operator.attrgetter("updated_at"),
diff --git a/skore/tests/integration/ui/test_ui.py b/skore/tests/integration/ui/test_ui.py
index 44b15d7a3..9d9a481bd 100644
--- a/skore/tests/integration/ui/test_ui.py
+++ b/skore/tests/integration/ui/test_ui.py
@@ -33,7 +33,7 @@ def test_get_items(client, in_memory_project):
     in_memory_project.put("test", "version_1")
     in_memory_project.put("test", "version_2")
 
-    items = in_memory_project.get_item_versions("test")
+    items = in_memory_project.item_repository.get_item_versions("test")
 
     response = client.get("/api/project/items")
     assert response.status_code == 200
diff --git a/skore/tests/unit/project/test_project.py b/skore/tests/unit/project/test_project.py
index f5a842011..48b657534 100644
--- a/skore/tests/unit/project/test_project.py
+++ b/skore/tests/unit/project/test_project.py
@@ -19,6 +19,11 @@
 from skore.project.create import _create, _validate_project_name
 
 
+@pytest.fixture(autouse=True)
+def monkeypatch_datetime(monkeypatch, MockDatetime):
+    monkeypatch.setattr("skore.persistence.item.item.datetime", MockDatetime)
+
+
 def test_put_string_item(in_memory_project):
     in_memory_project.put("string_item", "Hello, World!")
     assert in_memory_project.get("string_item") == "Hello, World!"
@@ -145,19 +150,19 @@ def test_put(in_memory_project):
     in_memory_project.put("key3", 3)
     in_memory_project.put("key4", 4)
 
-    assert in_memory_project.list_item_keys() == ["key1", "key2", "key3", "key4"]
+    assert in_memory_project.keys() == ["key1", "key2", "key3", "key4"]
 
 
 def test_put_kwargs(in_memory_project):
     in_memory_project.put(key="key1", value=1)
-    assert in_memory_project.list_item_keys() == ["key1"]
+    assert in_memory_project.keys() == ["key1"]
 
 
 def test_put_wrong_key_type(in_memory_project):
     with pytest.raises(TypeError):
         in_memory_project.put(key=2, value=1)
 
-    assert in_memory_project.list_item_keys() == []
+    assert in_memory_project.keys() == []
 
 
 def test_put_twice(in_memory_project):
@@ -167,39 +172,49 @@ def test_put_twice(in_memory_project):
     assert in_memory_project.get("key2") == 5
 
 
-def test_get(in_memory_project):
-    in_memory_project.put("key1", 1)
-    assert in_memory_project.get("key1") == 1
-
-    with pytest.raises(KeyError):
-        in_memory_project.get("key2")
-
-
-def test_get_item_versions(in_memory_project):
-    in_memory_project.put("key", 1)
-    in_memory_project.put("key", 2)
+def test_get(in_memory_project, mock_nowstr):
+    in_memory_project.put("key", 1, note="1")
+    in_memory_project.put("key", 2, note="2")
 
-    items = in_memory_project.get_item_versions("key")
+    assert in_memory_project.get("key") == 2
+    assert in_memory_project.get("key", latest=True, metadata=False) == 2
+    assert in_memory_project.get("key", latest=False, metadata=False) == [1, 2]
+    assert in_memory_project.get("key", latest=False, metadata=True) == [
+        {
+            "value": 1,
+            "date": mock_nowstr,
+            "note": "1",
+        },
+        {
+            "value": 2,
+            "date": mock_nowstr,
+            "note": "2",
+        },
+    ]
+    assert in_memory_project.get("key", latest=True, metadata=True) == {
+        "value": 2,
+        "date": mock_nowstr,
+        "note": "2",
+    }
 
-    assert len(items) == 2
-    assert items[0].primitive == 1
-    assert items[1].primitive == 2
+    with pytest.raises(KeyError):
+        in_memory_project.get("<unknown>")
 
 
 def test_delete(in_memory_project):
     in_memory_project.put("key1", 1)
-    in_memory_project.delete_item("key1")
+    in_memory_project.delete("key1")
 
-    assert in_memory_project.list_item_keys() == []
+    assert in_memory_project.keys() == []
 
     with pytest.raises(KeyError):
-        in_memory_project.delete_item("key2")
+        in_memory_project.delete("key2")
 
 
 def test_keys(in_memory_project):
     in_memory_project.put("key1", 1)
     in_memory_project.put("key2", 2)
-    assert in_memory_project.list_item_keys() == ["key1", "key2"]
+    assert in_memory_project.keys() == ["key1", "key2"]
 
 
 def test_view(in_memory_project):
@@ -222,7 +237,7 @@ def test_put_several_complex(in_memory_project):
     in_memory_project.put("a", int)
     in_memory_project.put("b", float)
 
-    assert in_memory_project.list_item_keys() == ["a", "b"]
+    assert in_memory_project.keys() == ["a", "b"]
 
 
 def test_put_key_is_a_tuple(in_memory_project):
@@ -230,7 +245,7 @@ def test_put_key_is_a_tuple(in_memory_project):
     with pytest.raises(TypeError):
         in_memory_project.put(("a", "foo"), ("b", "bar"))
 
-    assert in_memory_project.list_item_keys() == []
+    assert in_memory_project.keys() == []
 
 
 def test_put_key_is_a_set(in_memory_project):
@@ -238,7 +253,7 @@ def test_put_key_is_a_set(in_memory_project):
     with pytest.raises(TypeError):
         in_memory_project.put(set(), "hello")
 
-    assert in_memory_project.list_item_keys() == []
+    assert in_memory_project.keys() == []
 
 
 def test_put_wrong_key_and_value_raise(in_memory_project):

From 602b8941b2d248d3c0f758f4ef0108d338f5b4fa Mon Sep 17 00:00:00 2001
From: Thomas S <thomas@probabl.ai>
Date: Wed, 15 Jan 2025 13:03:17 +0100
Subject: [PATCH 17/22] [skip ci] Fix examples and sphinx

---
 examples/getting_started/plot_working_with_projects.py | 8 ++++----
 sphinx/api.rst                                         | 2 --
 2 files changed, 4 insertions(+), 6 deletions(-)

diff --git a/examples/getting_started/plot_working_with_projects.py b/examples/getting_started/plot_working_with_projects.py
index 4897b4738..ef65603de 100644
--- a/examples/getting_started/plot_working_with_projects.py
+++ b/examples/getting_started/plot_working_with_projects.py
@@ -71,20 +71,20 @@
 #   see :ref:`example_tracking_items`.
 
 # %%
-# By using the :func:`~skore.Project.delete_item` method, we can also delete an object
+# By using the :func:`~skore.Project.delete` method, we can also delete an object
 # so that our skore UI does not become cluttered:
 
 # %%
 my_project.put("my_int_2", 10)
 
 # %%
-my_project.delete_item("my_int_2")
+my_project.delete("my_int_2")
 
 # %%
 # We can display all the keys in our project:
 
 # %%
-my_project.list_item_keys()
+my_project.keys()
 
 # %%
 # Storing strings and texts
@@ -127,7 +127,7 @@ def my_func(x):
 my_project.put(
     "my_string_3",
     "<p><h1>Title</h1> <b>bold</b>, <i>italic</i>, etc.</p>",
-    display_as="html",
+    display_as="HTML",
 )
 
 # %%
diff --git a/sphinx/api.rst b/sphinx/api.rst
index b5d5527d4..09a3bfd6a 100644
--- a/sphinx/api.rst
+++ b/sphinx/api.rst
@@ -20,7 +20,6 @@ These functions and classes are meant for managing a Project.
     :caption: Managing a project
 
     Project
-    item.primitive_item.PrimitiveItem
     open
 
 Get assistance when developing ML/DS projects
@@ -35,7 +34,6 @@ These functions and classes enhance scikit-learn's ones.
 
     train_test_split
     CrossValidationReporter
-    item.cross_validation_item.CrossValidationItem
 
 Report for a single estimator
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

From 71aec33a9c85dc78df37f8d24c3e920cdc1e878d Mon Sep 17 00:00:00 2001
From: Thomas S <thomas@probabl.ai>
Date: Wed, 15 Jan 2025 14:59:28 +0100
Subject: [PATCH 18/22] [skip ci] Hide view API

---
 skore/src/skore/project/create.py        |  2 +-
 skore/src/skore/project/project.py       | 50 ------------------------
 skore/src/skore/ui/project_routes.py     |  7 ++--
 skore/tests/integration/ui/test_ui.py    |  2 +-
 skore/tests/unit/project/test_project.py | 17 --------
 5 files changed, 6 insertions(+), 72 deletions(-)

diff --git a/skore/src/skore/project/create.py b/skore/src/skore/project/create.py
index e5a7e92de..fa6eac7f2 100644
--- a/skore/src/skore/project/create.py
+++ b/skore/src/skore/project/create.py
@@ -143,7 +143,7 @@ def _create(
             ) from e
 
         p = _load(project_directory)
-        p.put_view("default", View(layout=[]))
+        p.view_repository.put_view("default", View(layout=[]))
 
         console.rule("[bold cyan]skore[/bold cyan]")
         console.print(f"Project file '{project_directory}' was successfully created.")
diff --git a/skore/src/skore/project/project.py b/skore/src/skore/project/project.py
index 6271d8785..acba73822 100644
--- a/skore/src/skore/project/project.py
+++ b/skore/src/skore/project/project.py
@@ -10,7 +10,6 @@
 if TYPE_CHECKING:
     from skore.persistence import (
         ItemRepository,
-        View,
         ViewRepository,
     )
 
@@ -182,55 +181,6 @@ def delete(self, key: str):
         """
         self.item_repository.delete_item(key)
 
-    def put_view(self, key: str, view: View):
-        """Add a view to the Project."""
-        self.view_repository.put_view(key, view)
-
-    def get_view(self, key: str) -> View:
-        """Get the view corresponding to ``key`` from the Project.
-
-        Parameters
-        ----------
-        key : str
-            The key of the item to get.
-
-        Returns
-        -------
-        View
-            The view corresponding to ``key``.
-
-        Raises
-        ------
-        KeyError
-            If the key does not correspond to any view.
-        """
-        return self.view_repository.get_view(key)
-
-    def delete_view(self, key: str):
-        """Delete the view corresponding to ``key`` from the Project.
-
-        Parameters
-        ----------
-        key : str
-            The key corresponding to the view to delete.
-
-        Raises
-        ------
-        KeyError
-            If the key does not correspond to any view.
-        """
-        return self.view_repository.delete_view(key)
-
-    def list_view_keys(self) -> list[str]:
-        """List all view keys in the Project.
-
-        Returns
-        -------
-        list[str]
-            The list of view keys. The list is empty if there is no view.
-        """
-        return self.view_repository.keys()
-
     def set_note(self, key: str, message: str, *, version=-1):
         """Attach a note to key ``key``.
 
diff --git a/skore/src/skore/ui/project_routes.py b/skore/src/skore/ui/project_routes.py
index e3ac728cb..5606bbd39 100644
--- a/skore/src/skore/ui/project_routes.py
+++ b/skore/src/skore/ui/project_routes.py
@@ -56,7 +56,8 @@ def __project_as_serializable(project: Project) -> SerializableProject:
     }
 
     views = {
-        key: project.get_view(key).layout for key in project.view_repository.keys()
+        key: project.view_repository.get_view(key).layout
+        for key in project.view_repository.keys()
     }
 
     return SerializableProject(
@@ -81,7 +82,7 @@ async def put_view(request: Request, key: str, layout: Layout):
     project: Project = request.app.state.project
 
     view = View(layout=layout)
-    project.put_view(key, view)
+    project.view_repository.put_view(key, view)
 
     return __project_as_serializable(project)
 
@@ -92,7 +93,7 @@ async def delete_view(request: Request, key: str):
     project: Project = request.app.state.project
 
     try:
-        project.delete_view(key)
+        project.view_repository.delete_view(key)
     except KeyError:
         raise HTTPException(
             status_code=status.HTTP_404_NOT_FOUND, detail="View not found"
diff --git a/skore/tests/integration/ui/test_ui.py b/skore/tests/integration/ui/test_ui.py
index 9d9a481bd..c5170a958 100644
--- a/skore/tests/integration/ui/test_ui.py
+++ b/skore/tests/integration/ui/test_ui.py
@@ -60,7 +60,7 @@ def test_put_view_layout(client):
 
 
 def test_delete_view(client, in_memory_project):
-    in_memory_project.put_view("hello", View(layout=[]))
+    in_memory_project.view_repository.put_view("hello", View(layout=[]))
     response = client.delete("/api/project/views?key=hello")
     assert response.status_code == 202
 
diff --git a/skore/tests/unit/project/test_project.py b/skore/tests/unit/project/test_project.py
index 48b657534..cf2f7225e 100644
--- a/skore/tests/unit/project/test_project.py
+++ b/skore/tests/unit/project/test_project.py
@@ -15,7 +15,6 @@
     InvalidProjectNameError,
     ProjectCreationError,
 )
-from skore.persistence.view.view import View
 from skore.project.create import _create, _validate_project_name
 
 
@@ -217,22 +216,6 @@ def test_keys(in_memory_project):
     assert in_memory_project.keys() == ["key1", "key2"]
 
 
-def test_view(in_memory_project):
-    layout = ["key1", "key2"]
-
-    view = View(layout=layout)
-
-    in_memory_project.put_view("view", view)
-    assert in_memory_project.get_view("view") == view
-
-
-def test_list_view_keys(in_memory_project):
-    view = View(layout=[])
-
-    in_memory_project.put_view("view", view)
-    assert in_memory_project.list_view_keys() == ["view"]
-
-
 def test_put_several_complex(in_memory_project):
     in_memory_project.put("a", int)
     in_memory_project.put("b", float)

From a85d2f18b06130c95e3245f2c6dc9f9e66ed206c Mon Sep 17 00:00:00 2001
From: Thomas S <thomas@probabl.ai>
Date: Wed, 15 Jan 2025 15:10:04 +0100
Subject: [PATCH 19/22] [skip ci] Fix linter

---
 .../persistence/repository/item_repository.py | 14 ++++++++++-
 .../persistence/repository/view_repository.py | 16 +++++++++++--
 skore/src/skore/project/project.py            | 23 ++++++++++++++++++-
 skore/src/skore/ui/project_routes.py          |  6 ++---
 4 files changed, 52 insertions(+), 7 deletions(-)

diff --git a/skore/src/skore/persistence/repository/item_repository.py b/skore/src/skore/persistence/repository/item_repository.py
index 601c7b20b..97e29e174 100644
--- a/skore/src/skore/persistence/repository/item_repository.py
+++ b/skore/src/skore/persistence/repository/item_repository.py
@@ -6,6 +6,7 @@
 
 from __future__ import annotations
 
+from collections.abc import Iterator
 from typing import TYPE_CHECKING, Union
 
 import skore.persistence.item
@@ -129,10 +130,21 @@ def keys(self) -> list[str]:
         Returns
         -------
         list[str]
-            A list of all keys in the storage.
+            A list of all keys.
         """
         return list(self.storage.keys())
 
+    def __iter__(self) -> Iterator[str]:
+        """
+        Yield the keys of items stored in the repository.
+
+        Returns
+        -------
+        Iterator[str]
+            An iterator yielding all keys.
+        """
+        yield from self.storage
+
     def set_item_note(self, key: str, message: str, *, version=-1):
         """Attach a note to key ``key``.
 
diff --git a/skore/src/skore/persistence/repository/view_repository.py b/skore/src/skore/persistence/repository/view_repository.py
index 8ec7dcfc9..02f42baa8 100644
--- a/skore/src/skore/persistence/repository/view_repository.py
+++ b/skore/src/skore/persistence/repository/view_repository.py
@@ -2,6 +2,7 @@
 
 from __future__ import annotations
 
+from collections.abc import Iterator
 from typing import TYPE_CHECKING
 
 if TYPE_CHECKING:
@@ -65,11 +66,22 @@ def delete_view(self, key: str):
 
     def keys(self) -> list[str]:
         """
-        Get all keys of items stored in the repository.
+        Get all keys of views stored in the repository.
 
         Returns
         -------
         list[str]
-            A list of all keys in the storage.
+            A list of all keys.
         """
         return list(self.storage.keys())
+
+    def __iter__(self) -> Iterator[str]:
+        """
+        Yield the keys of views stored in the repository.
+
+        Returns
+        -------
+        Iterator[str]
+            An iterator yielding all keys.
+        """
+        yield from self.storage
diff --git a/skore/src/skore/project/project.py b/skore/src/skore/project/project.py
index acba73822..d485e3f72 100644
--- a/skore/src/skore/project/project.py
+++ b/skore/src/skore/project/project.py
@@ -3,6 +3,7 @@
 from __future__ import annotations
 
 import logging
+from collections.abc import Iterator
 from typing import TYPE_CHECKING, Any, Literal, Optional, Union
 
 from skore.persistence.item import item_to_object, object_to_item
@@ -133,7 +134,8 @@ def get(self, key, *, latest=True, metadata=False):
         value : any
             Value associated to ``key``, when latest=True and metadata=False.
         value_and_metadata : dict
-            Value associated to ``key`` with its metadata, when latest=True and metadata=True.
+            Value associated to ``key`` with its metadata, when latest=True and
+            metadata=True.
         list_of_values : list[any]
             Values associated to ``key``, ordered by date, when latest=False.
         list_of_values_and_metadata : list[dict]
@@ -164,8 +166,27 @@ def dto(item):
         return list(map(dto, self.item_repository.get_item_versions(key)))
 
     def keys(self) -> list[str]:
+        """
+        Get all keys of items stored in the project.
+
+        Returns
+        -------
+        list[str]
+            A list of all keys.
+        """
         return self.item_repository.keys()
 
+    def __iter__(self) -> Iterator[str]:
+        """
+        Yield the keys of items stored in the project.
+
+        Returns
+        -------
+        Iterator[str]
+            An iterator yielding all keys.
+        """
+        yield from self.item_repository
+
     def delete(self, key: str):
         """Delete the item corresponding to ``key`` from the Project.
 
diff --git a/skore/src/skore/ui/project_routes.py b/skore/src/skore/ui/project_routes.py
index 5606bbd39..04d1e88e1 100644
--- a/skore/src/skore/ui/project_routes.py
+++ b/skore/src/skore/ui/project_routes.py
@@ -52,12 +52,12 @@ def __project_as_serializable(project: Project) -> SerializableProject:
             __item_as_serializable(key, item)
             for item in project.item_repository.get_item_versions(key)
         ]
-        for key in project.item_repository.keys()
+        for key in project.item_repository
     }
 
     views = {
         key: project.view_repository.get_view(key).layout
-        for key in project.view_repository.keys()
+        for key in project.view_repository
     }
 
     return SerializableProject(
@@ -116,7 +116,7 @@ async def get_activity(
     return sorted(
         (
             __item_as_serializable(key, version)
-            for key in project.item_repository.keys()
+            for key in project.item_repository
             for version in project.item_repository.get_item_versions(key)
             if datetime.fromisoformat(version.updated_at) > after
         ),

From fe9c497f613ae7403d16c3f311ba384871bb4f2e Mon Sep 17 00:00:00 2001
From: Thomas S <thomas@probabl.ai>
Date: Thu, 16 Jan 2025 15:41:32 +0100
Subject: [PATCH 20/22] [skip ci] Leave pillow from MediaItem to
 PillowImageItem

---
 skore/src/skore/persistence/item/__init__.py  |   5 +
 .../item/cross_validation_reporter_item.py    |  10 +-
 .../src/skore/persistence/item/media_item.py  |  54 ++--------
 .../src/skore/persistence/item/pickle_item.py |   3 +-
 .../persistence/item/pillow_image_item.py     | 102 ++++++++++++++++++
 skore/tests/integration/ui/test_ui.py         |  48 +++++++--
 skore/tests/unit/item/test_media_item.py      |  18 ----
 .../tests/unit/item/test_pillow_image_item.py |  56 ++++++++++
 skore/tests/unit/project/test_project.py      |  18 ++--
 9 files changed, 222 insertions(+), 92 deletions(-)
 create mode 100644 skore/src/skore/persistence/item/pillow_image_item.py
 create mode 100644 skore/tests/unit/item/test_pillow_image_item.py

diff --git a/skore/src/skore/persistence/item/__init__.py b/skore/src/skore/persistence/item/__init__.py
index aa9ea9319..de24446be 100644
--- a/skore/src/skore/persistence/item/__init__.py
+++ b/skore/src/skore/persistence/item/__init__.py
@@ -13,6 +13,7 @@
 from .pandas_dataframe_item import PandasDataFrameItem
 from .pandas_series_item import PandasSeriesItem
 from .pickle_item import PickleItem
+from .pillow_image_item import PillowImageItem
 from .polars_dataframe_item import PolarsDataFrameItem
 from .polars_series_item import PolarsSeriesItem
 from .primitive_item import PrimitiveItem
@@ -50,6 +51,7 @@ def object_to_item(
             MediaItem,
             SkrubTableReportItem,
             CrossValidationReporterItem,
+            PillowImageItem,
         ):
             with suppress(ImportError, ItemTypeError):
                 # ImportError:
@@ -91,6 +93,8 @@ def item_to_object(item: Item) -> Any:
         return item.reporter
     elif isinstance(item, MediaItem):
         return item.media_bytes
+    elif isinstance(item, PillowImageItem):
+        return item.image
     elif isinstance(item, PickleItem):
         return item.object
     else:
@@ -105,6 +109,7 @@ def item_to_object(item: Item) -> Any:
     "PandasDataFrameItem",
     "PandasSeriesItem",
     "PickleItem",
+    "PillowImageItem",
     "PolarsDataFrameItem",
     "PolarsSeriesItem",
     "PrimitiveItem",
diff --git a/skore/src/skore/persistence/item/cross_validation_reporter_item.py b/skore/src/skore/persistence/item/cross_validation_reporter_item.py
index ecad01237..775133e69 100644
--- a/skore/src/skore/persistence/item/cross_validation_reporter_item.py
+++ b/skore/src/skore/persistence/item/cross_validation_reporter_item.py
@@ -14,7 +14,6 @@
 import pickle
 import re
 import statistics
-from functools import cached_property
 from typing import TYPE_CHECKING, Literal, Optional, TypedDict
 
 import numpy
@@ -204,14 +203,9 @@ def factory(cls, reporter: CrossValidationReporter) -> CrossValidationReporterIt
         if not isinstance(reporter, CrossValidationReporter):
             raise ItemTypeError(f"Type '{reporter.__class__}' is not supported.")
 
-        instance = cls(pickle.dumps(reporter))
+        return cls(pickle.dumps(reporter))
 
-        # add reporter as cached property
-        instance.reporter = reporter
-
-        return instance
-
-    @cached_property
+    @property
     def reporter(self) -> CrossValidationReporter:
         """The CrossValidationReporter from the persistence."""
         return pickle.loads(self.reporter_bytes)
diff --git a/skore/src/skore/persistence/item/media_item.py b/skore/src/skore/persistence/item/media_item.py
index e57434743..e2a5cfb0a 100644
--- a/skore/src/skore/persistence/item/media_item.py
+++ b/skore/src/skore/persistence/item/media_item.py
@@ -1,6 +1,6 @@
 """MediaItem.
 
-This module defines the MediaItem class, which represents media items.
+This module defines the MediaItem class, used to persist media.
 """
 
 from __future__ import annotations
@@ -15,12 +15,11 @@
 if TYPE_CHECKING:
     from altair.vegalite.v5.schema.core import TopLevelSpec as Altair
     from matplotlib.figure import Figure as Matplotlib
-    from PIL.Image import Image as Pillow
     from plotly.basedatatypes import BaseFigure as Plotly
 
 
 def lazy_is_instance(object: Any, cls_fullname: str) -> bool:
-    """Return True if object is an instance of a class named `cls_fullname`."""
+    """Return True if object is an instance of `cls_fullname`."""
     return cls_fullname in {
         f"{cls.__module__}.{cls.__name__}" for cls in object.__class__.__mro__
     }
@@ -65,8 +64,8 @@ def __init__(
             The creation timestamp in ISO format.
         updated_at : str, optional
             The last update timestamp in ISO format.
-        note : Union[str, None]
-            An optional note.
+        note : str, optional
+            A note.
         """
         super().__init__(created_at, updated_at, note)
 
@@ -75,12 +74,7 @@ def __init__(
         self.media_type = media_type
 
     def as_serializable_dict(self):
-        """Get a serializable dict from the item.
-
-        Derived class must call their super implementation
-        and merge the result with their output.
-        """
-        d = super().as_serializable_dict()
+        """Return item as a JSONable dict to export to frontend."""
         if "text" in self.media_type:
             value = self.media_bytes.decode(encoding=self.media_encoding)
             media_type = f"{self.media_type}"
@@ -88,13 +82,10 @@ def as_serializable_dict(self):
             value = base64.b64encode(self.media_bytes).decode()
             media_type = f"{self.media_type};base64"
 
-        d.update(
-            {
-                "media_type": media_type,
-                "value": value,
-            }
-        )
-        return d
+        return super().as_serializable_dict() | {
+            "media_type": media_type,
+            "value": value,
+        }
 
     @classmethod
     def factory(cls, media, *args, **kwargs):
@@ -127,8 +118,6 @@ def factory(cls, media, *args, **kwargs):
             return cls.factory_altair(media, *args, **kwargs)
         if lazy_is_instance(media, "matplotlib.figure.Figure"):
             return cls.factory_matplotlib(media, *args, **kwargs)
-        if lazy_is_instance(media, "PIL.Image.Image"):
-            return cls.factory_pillow(media, *args, **kwargs)
         if lazy_is_instance(media, "plotly.basedatatypes.BaseFigure"):
             return cls.factory_plotly(media, *args, **kwargs)
 
@@ -237,31 +226,6 @@ def factory_matplotlib(cls, media: Matplotlib) -> MediaItem:
                 media_type="image/svg+xml",
             )
 
-    @classmethod
-    def factory_pillow(cls, media: Pillow) -> MediaItem:
-        """
-        Create a new MediaItem instance from a Pillow image.
-
-        Parameters
-        ----------
-        media : Pillow
-            The Pillow image to store.
-
-        Returns
-        -------
-        MediaItem
-            A new MediaItem instance.
-        """
-        with BytesIO() as stream:
-            media.save(stream, format="png")
-            media_bytes = stream.getvalue()
-
-            return cls(
-                media_bytes=media_bytes,
-                media_encoding="utf-8",
-                media_type="image/png",
-            )
-
     @classmethod
     def factory_plotly(cls, media: Plotly) -> MediaItem:
         """
diff --git a/skore/src/skore/persistence/item/pickle_item.py b/skore/src/skore/persistence/item/pickle_item.py
index d2678f545..a80fea3de 100644
--- a/skore/src/skore/persistence/item/pickle_item.py
+++ b/skore/src/skore/persistence/item/pickle_item.py
@@ -6,7 +6,6 @@
 
 from __future__ import annotations
 
-from functools import cached_property
 from pickle import dumps, loads
 from typing import Any, Optional
 
@@ -47,7 +46,7 @@ def __init__(
 
         self.pickle_bytes = pickle_bytes
 
-    @cached_property
+    @property
     def object(self) -> Any:
         """The object from the persistence."""
         return loads(self.pickle_bytes)
diff --git a/skore/src/skore/persistence/item/pillow_image_item.py b/skore/src/skore/persistence/item/pillow_image_item.py
new file mode 100644
index 000000000..c67cde339
--- /dev/null
+++ b/skore/src/skore/persistence/item/pillow_image_item.py
@@ -0,0 +1,102 @@
+"""PillowImageItem.
+
+This module defines the PillowImageItem class, used to persist Pillow images.
+"""
+
+from __future__ import annotations
+
+from typing import TYPE_CHECKING, Optional
+
+from .item import Item, ItemTypeError
+from .media_item import lazy_is_instance
+
+if TYPE_CHECKING:
+    import PIL.Image
+
+
+class PillowImageItem(Item):
+    """A class used to persist a Pillow image."""
+
+    def __init__(
+        self,
+        image_bytes: bytes,
+        image_mode: str,
+        image_size: tuple[int],
+        created_at: Optional[str] = None,
+        updated_at: Optional[str] = None,
+        note: Optional[str] = None,
+    ):
+        """
+        Initialize a PillowImageItem.
+
+        Parameters
+        ----------
+        image_bytes : bytes
+            The raw bytes of the Pillow image.
+        image_mode : str
+            The image mode.
+        image_size : tuple[int]
+            The image size.
+        created_at : str, optional
+            The creation timestamp in ISO format.
+        updated_at : str, optional
+            The last update timestamp in ISO format.
+        note : str, optional
+            A note.
+        """
+        super().__init__(created_at, updated_at, note)
+
+        self.image_bytes = image_bytes
+        self.image_mode = image_mode
+        self.image_size = image_size
+
+    @classmethod
+    def factory(cls, image: PIL.Image.Image) -> PillowImageItem:
+        """
+        Create a new PillowImageItem instance from a Pillow image.
+
+        Parameters
+        ----------
+        image : PIL.Image.Image
+            The Pillow image to store.
+
+        Returns
+        -------
+        PillowImageItem
+            A new PillowImageItem instance.
+        """
+        if not lazy_is_instance(image, "PIL.Image.Image"):
+            raise ItemTypeError(f"Type '{image.__class__}' is not supported.")
+
+        return cls(
+            image_bytes=image.tobytes(),
+            image_mode=image.mode,
+            image_size=image.size,
+        )
+
+    @property
+    def image(self) -> PIL.Image.Image:
+        """The image from the persistence."""
+        import PIL.Image
+
+        return PIL.Image.frombytes(
+            mode=self.image_mode,
+            size=self.image_size,
+            data=self.image_bytes,
+        )
+
+    def as_serializable_dict(self):
+        """Return item as a JSONable dict to export to frontend."""
+        import base64
+        import io
+
+        with io.BytesIO() as stream:
+            self.image.save(stream, format="png")
+
+            png_bytes = stream.getvalue()
+            png_bytes_b64 = base64.b64encode(png_bytes).decode()
+
+        return super().as_serializable_dict() | {
+            "media_type": "image/png;base64",
+            "value": png_bytes_b64,
+        }
diff --git a/skore/tests/integration/ui/test_ui.py b/skore/tests/integration/ui/test_ui.py
index c5170a958..b9470a50d 100644
--- a/skore/tests/integration/ui/test_ui.py
+++ b/skore/tests/integration/ui/test_ui.py
@@ -1,4 +1,6 @@
+import base64
 import datetime
+import io
 import json
 
 import numpy
@@ -20,6 +22,11 @@ def client(in_memory_project):
     return TestClient(app=create_app(project=in_memory_project))
 
 
+@pytest.fixture
+def monkeypatch_datetime(monkeypatch, MockDatetime):
+    monkeypatch.setattr("skore.persistence.item.item.datetime", MockDatetime)
+
+
 def test_app_state(client):
     assert client.app.state.project is not None
 
@@ -130,19 +137,42 @@ def test_serialize_sklearn_estimator(client, in_memory_project):
     assert project["items"]["estimator"][0]["value"] is not None
 
 
-def test_serialize_media_item(client, in_memory_project):
-    imarray = numpy.random.rand(100, 100, 3) * 255
-    img = Image.fromarray(imarray.astype("uint8")).convert("RGBA")
-    in_memory_project.put("img", img)
+def test_serialize_pillow_item(
+    client,
+    in_memory_project,
+    monkeypatch_datetime,
+    mock_nowstr,
+):
+    image_array = numpy.random.rand(100, 100, 3) * 255
+    image = Image.fromarray(image_array.astype("uint8")).convert("RGBA")
+
+    with io.BytesIO() as stream:
+        image.save(stream, format="png")
 
-    html = "<h1>éપUœALDXIWDŸΩΩ</h1>"
-    in_memory_project.put("html", html)
+        png_bytes = stream.getvalue()
+        png_bytes_b64 = base64.b64encode(png_bytes).decode()
 
+    in_memory_project.put("image", image)
     response = client.get("/api/project/items")
+
     assert response.status_code == 200
-    project = response.json()
-    assert "image" in project["items"]["img"][0]["media_type"]
-    assert project["items"]["html"][0]["value"] == html
+    assert response.json() == {
+        "views": {},
+        "items": {
+            "image": [
+                {
+                    "name": "image",
+                    "media_type": "image/png;base64",
+                    "value": png_bytes_b64,
+                    "updated_at": mock_nowstr,
+                    "created_at": mock_nowstr,
+                }
+            ]
+        },
+    }
+
+
+def test_serialize_media_item(client, in_memory_project): ...
 
 
 @pytest.fixture
diff --git a/skore/tests/unit/item/test_media_item.py b/skore/tests/unit/item/test_media_item.py
index 320da8d97..0794b50bc 100644
--- a/skore/tests/unit/item/test_media_item.py
+++ b/skore/tests/unit/item/test_media_item.py
@@ -1,8 +1,5 @@
-import io
-
 import altair
 import matplotlib.pyplot
-import PIL as pillow
 import plotly.graph_objects as go
 import pytest
 from skore.persistence.item import ItemTypeError, MediaItem
@@ -62,21 +59,6 @@ def test_factory_matplotlib(self, mock_nowstr):
         assert item.created_at == mock_nowstr
         assert item.updated_at == mock_nowstr
 
-    def test_factory_pillow(self, mock_nowstr):
-        image = pillow.Image.new("RGB", (100, 100), color="red")
-
-        with io.BytesIO() as stream:
-            image.save(stream, format="png")
-            image_bytes = stream.getvalue()
-
-        item = MediaItem.factory(image)
-
-        assert item.media_bytes == image_bytes
-        assert item.media_encoding == "utf-8"
-        assert item.media_type == "image/png"
-        assert item.created_at == mock_nowstr
-        assert item.updated_at == mock_nowstr
-
     def test_factory_plotly(self, mock_nowstr):
         figure = go.Figure(data=[go.Bar(x=[1, 2, 3], y=[1, 3, 2])])
         figure_bytes = figure.to_json().encode("utf-8")
diff --git a/skore/tests/unit/item/test_pillow_image_item.py b/skore/tests/unit/item/test_pillow_image_item.py
new file mode 100644
index 000000000..3e43fa94b
--- /dev/null
+++ b/skore/tests/unit/item/test_pillow_image_item.py
@@ -0,0 +1,56 @@
+import base64
+import io
+
+import PIL.Image
+import pytest
+from skore.persistence.item import ItemTypeError, PillowImageItem
+
+
+class TestPillowImageItem:
+    @pytest.fixture(autouse=True)
+    def monkeypatch_datetime(self, monkeypatch, MockDatetime):
+        monkeypatch.setattr("skore.persistence.item.item.datetime", MockDatetime)
+
+    def test_factory(self, mock_nowstr):
+        image = PIL.Image.new("RGB", (100, 100), color="red")
+        item = PillowImageItem.factory(image)
+
+        assert item.image_bytes == image.tobytes()
+        assert item.image_mode == image.mode
+        assert item.image_size == image.size
+        assert item.created_at == mock_nowstr
+        assert item.updated_at == mock_nowstr
+
+    def test_factory_exception(self):
+        with pytest.raises(ItemTypeError):
+            PillowImageItem.factory(None)
+
+    def test_image(self):
+        image = PIL.Image.new("RGB", (100, 100), color="red")
+        item1 = PillowImageItem.factory(image)
+        item2 = PillowImageItem(
+            image_bytes=image.tobytes(),
+            image_mode=image.mode,
+            image_size=image.size,
+        )
+
+        assert item1.image == image
+        assert item2.image == image
+
+    def test_as_serializable_dict(self, mock_nowstr):
+        image = PIL.Image.new("RGB", (100, 100), color="red")
+        item = PillowImageItem.factory(image)
+
+        with io.BytesIO() as stream:
+            image.save(stream, format="png")
+
+            png_bytes = stream.getvalue()
+            png_bytes_b64 = base64.b64encode(png_bytes).decode()
+
+        assert item.as_serializable_dict() == {
+            "updated_at": mock_nowstr,
+            "created_at": mock_nowstr,
+            "note": None,
+            "media_type": "image/png;base64",
+            "value": png_bytes_b64,
+        }
diff --git a/skore/tests/unit/project/test_project.py b/skore/tests/unit/project/test_project.py
index cf2f7225e..eb9790169 100644
--- a/skore/tests/unit/project/test_project.py
+++ b/skore/tests/unit/project/test_project.py
@@ -1,5 +1,3 @@
-from io import BytesIO
-
 import altair
 import numpy
 import numpy.testing
@@ -124,14 +122,14 @@ def test_put_vega_chart(in_memory_project):
 
 
 def test_put_pil_image(in_memory_project):
-    # Add a PIL Image
-    pil_image = Image.new("RGB", (100, 100), color="red")
-    with BytesIO() as output:
-        # FIXME: Not JPEG!
-        pil_image.save(output, format="jpeg")
-
-    in_memory_project.put("pil_image", pil_image)  # MediaItem (PNG)
-    assert isinstance(in_memory_project.get("pil_image"), bytes)
+    image1 = Image.new("RGB", (100, 100), color="red")
+    image2 = Image.new("RGBA", (150, 150), color="blue")
+
+    in_memory_project.put("image1", image1)
+    in_memory_project.put("image2", image2)
+
+    assert in_memory_project.get("image1") == image1
+    assert in_memory_project.get("image2") == image2
 
 
 def test_put_rf_model(in_memory_project, monkeypatch):

From 4550767b1b8bd367caf2c3d7f456dc34895bdcbd Mon Sep 17 00:00:00 2001
From: Thomas S <thomas@probabl.ai>
Date: Thu, 16 Jan 2025 15:59:02 +0100
Subject: [PATCH 21/22] [skip ci] Allow to pass created_at/updated_at/note via
 factory to constructor in PillowImageItem and PickleItem

---
 skore/src/skore/persistence/item/pickle_item.py       | 4 ++--
 skore/src/skore/persistence/item/pillow_image_item.py | 3 ++-
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/skore/src/skore/persistence/item/pickle_item.py b/skore/src/skore/persistence/item/pickle_item.py
index a80fea3de..1074f474c 100644
--- a/skore/src/skore/persistence/item/pickle_item.py
+++ b/skore/src/skore/persistence/item/pickle_item.py
@@ -52,7 +52,7 @@ def object(self) -> Any:
         return loads(self.pickle_bytes)
 
     @classmethod
-    def factory(cls, object: Any) -> PickleItem:
+    def factory(cls, object: Any, /, **kwargs) -> PickleItem:
         """
         Create a new PickleItem with any object.
 
@@ -66,7 +66,7 @@ def factory(cls, object: Any) -> PickleItem:
         PickleItem
             A new PickleItem instance.
         """
-        return cls(dumps(object))
+        return cls(dumps(object), **kwargs)
 
     def as_serializable_dict(self):
         """Get a JSON serializable representation of the item."""
diff --git a/skore/src/skore/persistence/item/pillow_image_item.py b/skore/src/skore/persistence/item/pillow_image_item.py
index c67cde339..20f53a5f8 100644
--- a/skore/src/skore/persistence/item/pillow_image_item.py
+++ b/skore/src/skore/persistence/item/pillow_image_item.py
@@ -51,7 +51,7 @@ def __init__(
         self.image_size = image_size
 
     @classmethod
-    def factory(cls, image: PIL.Image.Image) -> PillowImageItem:
+    def factory(cls, image: PIL.Image.Image, /, **kwargs) -> PillowImageItem:
         """
         Create a new PillowImageItem instance from a Pillow image.
 
@@ -72,6 +72,7 @@ def factory(cls, image: PIL.Image.Image) -> PillowImageItem:
             image_bytes=image.tobytes(),
             image_mode=image.mode,
             image_size=image.size,
+            **kwargs,
         )
 
     @property

From 42d9b86169faa132b02047cb2294c5d6f2b33257 Mon Sep 17 00:00:00 2001
From: Thomas S <thomas@probabl.ai>
Date: Thu, 16 Jan 2025 17:11:18 +0100
Subject: [PATCH 22/22] [skip ci] Leave plotly from MediaItem to
 PlotlyFigureItem

---
 skore/src/skore/persistence/item/__init__.py  |  7 ++
 .../src/skore/persistence/item/media_item.py  | 28 -------
 .../persistence/item/plotly_figure_item.py    | 84 +++++++++++++++++++
 skore/tests/integration/ui/test_ui.py         | 32 +++++++
 skore/tests/unit/item/test_media_item.py      | 13 ---
 .../unit/item/test_plotly_figure_item.py      | 51 +++++++++++
 skore/tests/unit/project/test_project.py      | 12 ++-
 7 files changed, 185 insertions(+), 42 deletions(-)
 create mode 100644 skore/src/skore/persistence/item/plotly_figure_item.py
 create mode 100644 skore/tests/unit/item/test_plotly_figure_item.py

diff --git a/skore/src/skore/persistence/item/__init__.py b/skore/src/skore/persistence/item/__init__.py
index de24446be..3ed8abcd5 100644
--- a/skore/src/skore/persistence/item/__init__.py
+++ b/skore/src/skore/persistence/item/__init__.py
@@ -14,6 +14,7 @@
 from .pandas_series_item import PandasSeriesItem
 from .pickle_item import PickleItem
 from .pillow_image_item import PillowImageItem
+from .plotly_figure_item import PlotlyFigureItem
 from .polars_dataframe_item import PolarsDataFrameItem
 from .polars_series_item import PolarsSeriesItem
 from .primitive_item import PrimitiveItem
@@ -52,6 +53,7 @@ def object_to_item(
             SkrubTableReportItem,
             CrossValidationReporterItem,
             PillowImageItem,
+            PlotlyFigureItem,
         ):
             with suppress(ImportError, ItemTypeError):
                 # ImportError:
@@ -74,6 +76,8 @@ def object_to_item(
     # `note` attribute dynamically.
     item.note = note
 
+    # -> to change in each class
+
     return item
 
 
@@ -95,6 +99,8 @@ def item_to_object(item: Item) -> Any:
         return item.media_bytes
     elif isinstance(item, PillowImageItem):
         return item.image
+    elif isinstance(item, PlotlyFigureItem):
+        return item.figure
     elif isinstance(item, PickleItem):
         return item.object
     else:
@@ -110,6 +116,7 @@ def item_to_object(item: Item) -> Any:
     "PandasSeriesItem",
     "PickleItem",
     "PillowImageItem",
+    "PlotlyFigureItem",
     "PolarsDataFrameItem",
     "PolarsSeriesItem",
     "PrimitiveItem",
diff --git a/skore/src/skore/persistence/item/media_item.py b/skore/src/skore/persistence/item/media_item.py
index e2a5cfb0a..0ebb8858f 100644
--- a/skore/src/skore/persistence/item/media_item.py
+++ b/skore/src/skore/persistence/item/media_item.py
@@ -15,7 +15,6 @@
 if TYPE_CHECKING:
     from altair.vegalite.v5.schema.core import TopLevelSpec as Altair
     from matplotlib.figure import Figure as Matplotlib
-    from plotly.basedatatypes import BaseFigure as Plotly
 
 
 def lazy_is_instance(object: Any, cls_fullname: str) -> bool:
@@ -118,8 +117,6 @@ def factory(cls, media, *args, **kwargs):
             return cls.factory_altair(media, *args, **kwargs)
         if lazy_is_instance(media, "matplotlib.figure.Figure"):
             return cls.factory_matplotlib(media, *args, **kwargs)
-        if lazy_is_instance(media, "plotly.basedatatypes.BaseFigure"):
-            return cls.factory_plotly(media, *args, **kwargs)
 
         raise ItemTypeError(f"Type '{media.__class__}' is not supported.")
 
@@ -225,28 +222,3 @@ def factory_matplotlib(cls, media: Matplotlib) -> MediaItem:
                 media_encoding="utf-8",
                 media_type="image/svg+xml",
             )
-
-    @classmethod
-    def factory_plotly(cls, media: Plotly) -> MediaItem:
-        """
-        Create a new MediaItem instance from a Plotly figure.
-
-        Parameters
-        ----------
-        media : Plotly
-            The Plotly figure to store.
-
-        Returns
-        -------
-        MediaItem
-            A new MediaItem instance.
-        """
-        import plotly.io
-
-        media_bytes = plotly.io.to_json(media, engine="json").encode("utf-8")
-
-        return cls(
-            media_bytes=media_bytes,
-            media_encoding="utf-8",
-            media_type="application/vnd.plotly.v1+json",
-        )
diff --git a/skore/src/skore/persistence/item/plotly_figure_item.py b/skore/src/skore/persistence/item/plotly_figure_item.py
new file mode 100644
index 000000000..a705ca48a
--- /dev/null
+++ b/skore/src/skore/persistence/item/plotly_figure_item.py
@@ -0,0 +1,84 @@
+"""PlotlyFigureItem.
+
+This module defines the PlotlyFigureItem class, used to persist Ploty figures.
+"""
+
+from __future__ import annotations
+
+from typing import TYPE_CHECKING, Optional
+
+from .item import Item, ItemTypeError
+from .media_item import lazy_is_instance
+
+if TYPE_CHECKING:
+    import plotly.basedatatypes as plotly
+
+
+class PlotlyFigureItem(Item):
+    """A class used to persist a Plotly figure."""
+
+    def __init__(
+        self,
+        figure_str: str,
+        created_at: Optional[str] = None,
+        updated_at: Optional[str] = None,
+        note: Optional[str] = None,
+    ):
+        """
+        Initialize a PlotlyFigureItem.
+
+        Parameters
+        ----------
+        figure_str : bytes
+            The JSON str of the Plotly figure.
+        created_at : str, optional
+            The creation timestamp in ISO format.
+        updated_at : str, optional
+            The last update timestamp in ISO format.
+        note : str, optional
+            A note.
+        """
+        super().__init__(created_at, updated_at, note)
+
+        self.figure_str = figure_str
+
+    @classmethod
+    def factory(cls, figure: plotly.BaseFigure, /, **kwargs) -> PlotlyFigureItem:
+        """
+        Create a new PlotlyFigureItem instance from a Plotly figure.
+
+        Parameters
+        ----------
+        figure : plotly.basedatatypes.BaseFigure
+            The Plotly figure to store.
+
+        Returns
+        -------
+        PlotlyFigureItem
+            A new PlotlyFigureItem instance.
+        """
+        if not lazy_is_instance(figure, "plotly.basedatatypes.BaseFigure"):
+            raise ItemTypeError(f"Type '{figure.__class__}' is not supported.")
+
+        import plotly.io
+
+        return cls(plotly.io.to_json(figure, engine="json"), **kwargs)
+
+    @property
+    def figure(self) -> plotly.BaseFigure:
+        """The figure from the persistence."""
+        import plotly.io
+
+        return plotly.io.from_json(self.figure_str)
+
+    def as_serializable_dict(self):
+        """Return item as a JSONable dict to export to frontend."""
+        import base64
+
+        figure_bytes = self.figure_str.encode("utf-8")
+        figure_bytes_b64 = base64.b64encode(figure_bytes).decode()
+
+        return super().as_serializable_dict() | {
+            "media_type": "application/vnd.plotly.v1+json;base64",
+            "value": figure_bytes_b64,
+        }
diff --git a/skore/tests/integration/ui/test_ui.py b/skore/tests/integration/ui/test_ui.py
index b9470a50d..d0a02d57d 100644
--- a/skore/tests/integration/ui/test_ui.py
+++ b/skore/tests/integration/ui/test_ui.py
@@ -172,6 +172,38 @@ def test_serialize_pillow_item(
     }
 
 
+def test_serialize_plotly_item(
+    client,
+    in_memory_project,
+    monkeypatch_datetime,
+    mock_nowstr,
+):
+    bar = plotly.graph_objects.Bar(x=[1, 2, 3], y=[1, 3, 2])
+    figure = plotly.graph_objects.Figure(data=[bar])
+    figure_str = plotly.io.to_json(figure, engine="json")
+    figure_bytes = figure_str.encode("utf-8")
+    figure_bytes_b64 = base64.b64encode(figure_bytes).decode()
+
+    in_memory_project.put("figure", figure)
+    response = client.get("/api/project/items")
+
+    assert response.status_code == 200
+    assert response.json() == {
+        "views": {},
+        "items": {
+            "figure": [
+                {
+                    "name": "figure",
+                    "media_type": "application/vnd.plotly.v1+json;base64",
+                    "value": figure_bytes_b64,
+                    "updated_at": mock_nowstr,
+                    "created_at": mock_nowstr,
+                }
+            ]
+        },
+    }
+
+
 def test_serialize_media_item(client, in_memory_project): ...
 
 
diff --git a/skore/tests/unit/item/test_media_item.py b/skore/tests/unit/item/test_media_item.py
index 0794b50bc..0db89c082 100644
--- a/skore/tests/unit/item/test_media_item.py
+++ b/skore/tests/unit/item/test_media_item.py
@@ -1,6 +1,5 @@
 import altair
 import matplotlib.pyplot
-import plotly.graph_objects as go
 import pytest
 from skore.persistence.item import ItemTypeError, MediaItem
 
@@ -59,18 +58,6 @@ def test_factory_matplotlib(self, mock_nowstr):
         assert item.created_at == mock_nowstr
         assert item.updated_at == mock_nowstr
 
-    def test_factory_plotly(self, mock_nowstr):
-        figure = go.Figure(data=[go.Bar(x=[1, 2, 3], y=[1, 3, 2])])
-        figure_bytes = figure.to_json().encode("utf-8")
-
-        item = MediaItem.factory(figure)
-
-        assert item.media_bytes == figure_bytes
-        assert item.media_encoding == "utf-8"
-        assert item.media_type == "application/vnd.plotly.v1+json"
-        assert item.created_at == mock_nowstr
-        assert item.updated_at == mock_nowstr
-
     def test_get_serializable_dict(self, mock_nowstr):
         item = MediaItem.factory("<content>")
 
diff --git a/skore/tests/unit/item/test_plotly_figure_item.py b/skore/tests/unit/item/test_plotly_figure_item.py
new file mode 100644
index 000000000..9d1f8f18e
--- /dev/null
+++ b/skore/tests/unit/item/test_plotly_figure_item.py
@@ -0,0 +1,51 @@
+import base64
+
+import plotly.graph_objects
+import plotly.io
+import pytest
+from skore.persistence.item import ItemTypeError, PlotlyFigureItem
+
+
+class TestPlotlyFigureItem:
+    @pytest.fixture(autouse=True)
+    def monkeypatch_datetime(self, monkeypatch, MockDatetime):
+        monkeypatch.setattr("skore.persistence.item.item.datetime", MockDatetime)
+
+    def test_factory(self, mock_nowstr):
+        bar = plotly.graph_objects.Bar(x=[1, 2, 3], y=[1, 3, 2])
+        figure = plotly.graph_objects.Figure(data=[bar])
+        item = PlotlyFigureItem.factory(figure)
+
+        assert item.figure_str == plotly.io.to_json(figure, engine="json")
+        assert item.created_at == mock_nowstr
+        assert item.updated_at == mock_nowstr
+
+    def test_factory_exception(self):
+        with pytest.raises(ItemTypeError):
+            PlotlyFigureItem.factory(None)
+
+    def test_figure(self):
+        bar = plotly.graph_objects.Bar(x=[1, 2, 3], y=[1, 3, 2])
+        figure = plotly.graph_objects.Figure(data=[bar])
+        item1 = PlotlyFigureItem.factory(figure)
+        item2 = PlotlyFigureItem(plotly.io.to_json(figure, engine="json"))
+
+        assert item1.figure == figure
+        assert item2.figure == figure
+
+    def test_as_serializable_dict(self, mock_nowstr):
+        bar = plotly.graph_objects.Bar(x=[1, 2, 3], y=[1, 3, 2])
+        figure = plotly.graph_objects.Figure(data=[bar])
+        figure_str = plotly.io.to_json(figure, engine="json")
+        figure_bytes = figure_str.encode("utf-8")
+        figure_bytes_b64 = base64.b64encode(figure_bytes).decode()
+
+        item = PlotlyFigureItem.factory(figure)
+
+        assert item.as_serializable_dict() == {
+            "updated_at": mock_nowstr,
+            "created_at": mock_nowstr,
+            "note": None,
+            "media_type": "application/vnd.plotly.v1+json;base64",
+            "value": figure_bytes_b64,
+        }
diff --git a/skore/tests/unit/project/test_project.py b/skore/tests/unit/project/test_project.py
index eb9790169..c37a8fdf0 100644
--- a/skore/tests/unit/project/test_project.py
+++ b/skore/tests/unit/project/test_project.py
@@ -3,6 +3,7 @@
 import numpy.testing
 import pandas
 import pandas.testing
+import plotly
 import polars
 import polars.testing
 import pytest
@@ -121,7 +122,7 @@ def test_put_vega_chart(in_memory_project):
     assert isinstance(in_memory_project.get("vega_chart"), bytes)
 
 
-def test_put_pil_image(in_memory_project):
+def test_put_pillow_image(in_memory_project):
     image1 = Image.new("RGB", (100, 100), color="red")
     image2 = Image.new("RGBA", (150, 150), color="blue")
 
@@ -132,6 +133,15 @@ def test_put_pil_image(in_memory_project):
     assert in_memory_project.get("image2") == image2
 
 
+def test_put_plotly_figure(in_memory_project):
+    bar = plotly.graph_objects.Bar(x=[1, 2, 3], y=[1, 3, 2])
+    figure = plotly.graph_objects.Figure(data=[bar])
+
+    in_memory_project.put("figure", figure)
+
+    assert in_memory_project.get("figure") == figure
+
+
 def test_put_rf_model(in_memory_project, monkeypatch):
     # Add a scikit-learn model
     monkeypatch.setattr("sklearn.utils.estimator_html_repr", lambda _: "")