diff --git a/libervia/backend/core/core_types.py b/libervia/backend/core/core_types.py
index 4e07ec05..8baaa2b8 100644
--- a/libervia/backend/core/core_types.py
+++ b/libervia/backend/core/core_types.py
@@ -29,6 +29,7 @@ from twisted.words.xish import domish
 from wokkel import disco
 
 from libervia.backend.core import exceptions
+from libervia.backend.models.core import MessageData
 
 if TYPE_CHECKING:
     from libervia.backend.core.xmpp import LiberviaRosterProtocol
@@ -49,8 +50,10 @@ MessageDataExtra = TypedDict(
 )
 
 
-MessageData = TypedDict(
-    "MessageData",
+# FIXME: deprecated, do not use this type. Use libervia.backend.models.core.MessageData
+#   instead.
+MessageDataLegacy = TypedDict(
+    "MessageDataLegacy",
     {
         "from": t_jid.JID,
         "to": t_jid.JID,
diff --git a/libervia/backend/core/xmpp.py b/libervia/backend/core/xmpp.py
index 99534e94..f6b31045 100644
--- a/libervia/backend/core/xmpp.py
+++ b/libervia/backend/core/xmpp.py
@@ -636,9 +636,9 @@ class SatXMPPEntity(core_types.SatXMPPEntity):
 
     def generate_message_xml(
         self,
-        data: core_types.MessageData,
+        data: core_types.MessageDataLegacy,
         post_xml_treatments: Optional[defer.Deferred] = None,
-    ) -> core_types.MessageData:
+    ) -> core_types.MessageDataLegacy:
         """Generate <message/> stanza from message data
 
         @param data: message data
diff --git a/libervia/backend/memory/encryption.py b/libervia/backend/memory/encryption.py
index 13cb5ad5..1a14fef7 100644
--- a/libervia/backend/memory/encryption.py
+++ b/libervia/backend/memory/encryption.py
@@ -26,7 +26,7 @@ from twisted.python import failure
 from libervia.backend.core.core_types import (
     EncryptionPlugin,
     EncryptionSession,
-    MessageData,
+    MessageDataLegacy,
 )
 from libervia.backend.core.i18n import D_, _
 from libervia.backend.core.constants import Const as C
@@ -540,7 +540,7 @@ class EncryptionHandler:
         return mess_data
 
     def is_encryption_requested(
-        self, mess_data: MessageData, namespace: Optional[str] = None
+        self, mess_data: MessageDataLegacy, namespace: Optional[str] = None
     ) -> bool:
         """Helper method to check if encryption is requested in an outgoind message
 
diff --git a/libervia/backend/plugins/plugin_sec_autocrypt.py b/libervia/backend/plugins/plugin_sec_autocrypt.py
index 5df23375..79227453 100644
--- a/libervia/backend/plugins/plugin_sec_autocrypt.py
+++ b/libervia/backend/plugins/plugin_sec_autocrypt.py
@@ -27,7 +27,7 @@ from twisted.words.protocols.jabber import jid
 from twisted.words.xish import domish
 
 from libervia.backend.core.constants import Const as C
-from libervia.backend.core.core_types import MessageData, SatXMPPEntity
+from libervia.backend.core.core_types import MessageDataLegacy, SatXMPPEntity
 from libervia.backend.core.i18n import _
 from libervia.backend.core.log import getLogger
 from libervia.backend.memory import persistent
@@ -159,7 +159,7 @@ class Autocrypt:
         client._autocrypt_gpg_provider = get_gpg_provider(self.host, client)
 
     async def handle_autocrypt_data(
-        self, client: SatXMPPEntity, mess_data: MessageData, autocrypt_data_raw: str
+        self, client: SatXMPPEntity, mess_data: MessageDataLegacy, autocrypt_data_raw: str
     ) -> None:
         """Process Autocrypt header from XMPP email gateway
 
@@ -211,8 +211,8 @@ class Autocrypt:
         client._autocrypt_seen.add(sender_email)
 
     def _check_headers(
-        self, client: SatXMPPEntity, mess_data: MessageData
-    ) -> MessageData:
+        self, client: SatXMPPEntity, mess_data: MessageDataLegacy
+    ) -> MessageDataLegacy:
         try:
             autocrypt_data = mess_data["extra"]["headers"]["autocrypt"]
         except KeyError:
@@ -232,7 +232,7 @@ class Autocrypt:
         post_treat.addCallback(partial(self._check_headers, client))
         return True
 
-    async def add_autocrypt_header(self, client, mess_data: MessageData) -> MessageData:
+    async def add_autocrypt_header(self, client, mess_data: MessageDataLegacy) -> MessageDataLegacy:
         to_jid = mess_data["to"]
         if await self.host.memory.disco.has_identity(
             client, "gateway", "smtp", jid.JID(to_jid.host)
@@ -265,7 +265,7 @@ class Autocrypt:
     ) -> Literal[True]:
         """Process the XEP-0131 related data to be sent"""
 
-        def add_headers(mess_data: MessageData) -> MessageData:
+        def add_headers(mess_data: MessageDataLegacy) -> MessageDataLegacy:
             extra = mess_data["extra"]
             self.move_keywords_to_headers(extra)
             # Now we parse headers, if any.
diff --git a/libervia/backend/plugins/plugin_xep_0384.py b/libervia/backend/plugins/plugin_xep_0384.py
index dbd0491b..795f3e29 100644
--- a/libervia/backend/plugins/plugin_xep_0384.py
+++ b/libervia/backend/plugins/plugin_xep_0384.py
@@ -45,7 +45,7 @@ import xmlschema
 
 from libervia.backend.core import exceptions
 from libervia.backend.core.constants import Const as C
-from libervia.backend.core.core_types import MessageData, SatXMPPEntity
+from libervia.backend.core.core_types import MessageDataLegacy, SatXMPPEntity
 from libervia.backend.core.i18n import _, D_
 from libervia.backend.core.log import getLogger, Logger
 from libervia.backend.core.main import LiberviaBackend
@@ -776,7 +776,7 @@ async def send_trust_messages(
 
         # Finally, encrypt and send the trust message!
         message_data = client.generate_message_xml(
-            MessageData(
+            MessageDataLegacy(
                 {
                     "from": own_jid,
                     "to": recipient_jid,
@@ -1296,7 +1296,7 @@ def make_session_manager(
                 raise omemo.UnknownNamespace(f"Unknown namespace: {message.namespace}")
 
             message_data = client.generate_message_xml(
-                MessageData(
+                MessageDataLegacy(
                     {
                         "from": client.jid,
                         "to": jid.JID(bare_jid),
@@ -1680,7 +1680,7 @@ class OMEMO:
         defer.ensureDeferred(self.get_session_manager(cast(str, client.profile)))
 
     async def cmd_omemo_reset(
-        self, client: SatXMPPClient, mess_data: MessageData
+        self, client: SatXMPPClient, mess_data: MessageDataLegacy
     ) -> Literal[False]:
         """Reset all sessions of devices that belong to the recipient of ``mess_data``.
 
diff --git a/libervia/backend/plugins/plugin_xep_0424.py b/libervia/backend/plugins/plugin_xep_0424.py
index 8ff3040d..3ffc270a 100644
--- a/libervia/backend/plugins/plugin_xep_0424.py
+++ b/libervia/backend/plugins/plugin_xep_0424.py
@@ -27,7 +27,7 @@ from zope.interface import implementer
 
 from libervia.backend.core import exceptions
 from libervia.backend.core.constants import Const as C
-from libervia.backend.core.core_types import MessageData, SatXMPPEntity
+from libervia.backend.core.core_types import MessageDataLegacy, SatXMPPEntity
 from libervia.backend.core.i18n import D_, _
 from libervia.backend.core.log import getLogger
 from libervia.backend.memory.sqla_mapping import History
@@ -210,7 +210,7 @@ class XEP_0424:
             del history.extra["attachments"]
         await self.host.memory.storage.add(history)
 
-        retract_data = MessageData(history.serialise())
+        retract_data = MessageDataLegacy(history.serialise())
         self.host.bridge.message_update(
             history.uid,
             C.MESS_UPDATE_RETRACT,