diff --git a/example/boilerplate.py b/example/boilerplate.py
index 538c3fd..8156769 100644
--- a/example/boilerplate.py
+++ b/example/boilerplate.py
@@ -1,10 +1,12 @@
 import json
+from datetime import datetime
 from logging import Logger, StreamHandler
 from os import environ as env
 from pathlib import Path
 from typing import Any, Optional
 
 from aiohttp import ClientSession
+from msgpackr.constants import UNDEFINED
 
 from novelai_api import NovelAIAPI
 from novelai_api.utils import get_encryption_key
@@ -85,6 +87,10 @@ class JSONEncoder(json.JSONEncoder):
     def default(self, o: Any) -> Any:
         if isinstance(o, bytes):
             return o.hex()
+        if o is UNDEFINED:
+            return "<UNDEFINED>"
+        if isinstance(o, datetime):
+            return o.isoformat()
 
         return super().default(o)
 
diff --git a/example/download_last_story_and_decrypt.py b/example/download_last_story_and_decrypt.py
new file mode 100644
index 0000000..5cd5f4e
--- /dev/null
+++ b/example/download_last_story_and_decrypt.py
@@ -0,0 +1,30 @@
+import asyncio
+from pathlib import Path
+
+from example.boilerplate import API, dumps
+from novelai_api.utils import decrypt_user_data
+
+dump_file = Path(__file__).parent.parent / "results" / "story.json"
+
+
+async def main():
+    async with API() as api_handler:
+        api = api_handler.api
+        key = api_handler.encryption_key
+
+        keystore = await api.high_level.get_keystore(key)
+
+        story = (await api.high_level.download_user_stories())[0]
+        decrypt_user_data(story, keystore)
+
+        storycontent_id = story["data"]["remoteStoryId"]
+
+        story_contents = await api.low_level.download_object("storycontent", storycontent_id)
+        decrypt_user_data(story_contents, keystore, True)
+
+        dump_file.parent.mkdir(exist_ok=True)
+        dump_file.write_text(dumps(story_contents), "utf-8")
+
+
+if __name__ == "__main__":
+    asyncio.run(main())
diff --git a/novelai_api/GlobalSettings.py b/novelai_api/GlobalSettings.py
index 0fd2bd3..9889041 100644
--- a/novelai_api/GlobalSettings.py
+++ b/novelai_api/GlobalSettings.py
@@ -712,14 +712,6 @@ class GlobalSettings:
             ".",
             ":",
             "\n",
-            "ve",
-            "s",
-            "t",
-            "n",
-            "d",
-            "ll",
-            "re",
-            "m",
             "-",
             "*",
             ")",
diff --git a/novelai_api/Msgpackr_Extensions.py b/novelai_api/Msgpackr_Extensions.py
new file mode 100644
index 0000000..d99cfc8
--- /dev/null
+++ b/novelai_api/Msgpackr_Extensions.py
@@ -0,0 +1,40 @@
+from typing import Any
+
+from msgpackr.constants import SKIP
+from msgpackr.unpack import MsgpackExtension
+
+
+class NAIExtension(MsgpackExtension):
+    @classmethod
+    def unpack(cls, _unpacker, _data: bytes, _pos: int, _length: int) -> Any:
+        return SKIP
+
+    # TODO: the data should be bundled in post_unpack
+
+    @classmethod
+    def pack(cls, _unpacker, data: Any) -> bytes:
+        return data
+
+
+class Ext20(NAIExtension):
+    EXT_TYPE = 20
+
+
+class Ext30(NAIExtension):
+    EXT_TYPE = 30
+
+
+class Ext31(NAIExtension):
+    EXT_TYPE = 31
+
+
+class Ext40(NAIExtension):
+    EXT_TYPE = 40
+
+
+class Ext41(NAIExtension):
+    EXT_TYPE = 41
+
+
+class Ext42(NAIExtension):
+    EXT_TYPE = 42
diff --git a/novelai_api/utils.py b/novelai_api/utils.py
index 17fead3..3e09ec4 100644
--- a/novelai_api/utils.py
+++ b/novelai_api/utils.py
@@ -7,15 +7,21 @@
 from zlib import decompress as inflate
 
 import argon2
+from msgpackr import Unpacker
 from nacl.exceptions import CryptoError
 from nacl.secret import SecretBox
 
 from novelai_api.Keystore import Keystore
+from novelai_api.Msgpackr_Extensions import Ext20, Ext30, Ext31, Ext40, Ext41, Ext42
 from novelai_api.NovelAIError import NovelAIError
 from novelai_api.Preset import Model, Preset
 from novelai_api.python_utils import assert_type
 from novelai_api.Tokenizer import Tokenizer
 
+unpacker = Unpacker()
+unpacker.register_extensions(Ext20, Ext30, Ext31, Ext40, Ext41, Ext42)
+unpacker_state = unpacker.export_state()
+
 
 # API utils
 def argon_hash(email: str, password: str, size: int, domain: str) -> str:
@@ -185,13 +191,16 @@ def compress_user_data(items: Union[List[Dict[str, Any]], Dict[str, Any]]):
             del item["decrypted"]
 
 
-def decrypt_user_data(items: Union[List[Dict[str, Any]], Dict[str, Any]], keystore: Keystore):
+def decrypt_user_data(
+    items: Union[List[Dict[str, Any]], Dict[str, Any]], keystore: Keystore, uncompress_document: bool = False
+):
     """
     Decrypt the data of each item in :ref: items
     If an item has already been decrypted, it won't be decrypted a second time
 
     :param items: Item or list of items to decrypt
     :param keystore: Keystore retrieved with the get_keystore method
+    :param uncompress_document: If True, the document will be decompressed
     """
 
     # 1 item
@@ -224,6 +233,11 @@ def decrypt_user_data(items: Union[List[Dict[str, Any]], Dict[str, Any]], keysto
                 item["nonce"] = nonce
                 item["decrypted"] = True
                 item["compressed"] = is_compressed
+
+                if uncompress_document and "document" in data:
+                    unpacker.restore_state(unpacker_state)
+                    data["document"] = unpacker.unpack(b64decode(data["document"]))
+
                 continue
 
             except json.JSONDecodeError:
diff --git a/pyproject.toml b/pyproject.toml
index fd84900..b633af1 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -29,7 +29,7 @@ ftfy = "^6.1.3"
 regex = "^2023.12.25"
 sentencepiece = "^0.2.0"
 poetry = "^1.7.1"
-# msgpack = "^1.0.5"
+msgpackr-python = "^0.1.2"
 
 [tool.poetry.group.dev.dependencies]
 python-dotenv = "^0.21.1"