diff --git a/ai_oca_bridge_chatter/models/ai_bridge_execution.py b/ai_oca_bridge_chatter/models/ai_bridge_execution.py
index adb74ca2..183b4828 100644
--- a/ai_oca_bridge_chatter/models/ai_bridge_execution.py
+++ b/ai_oca_bridge_chatter/models/ai_bridge_execution.py
@@ -1,6 +1,8 @@
 # Copyright 2025 Dixmit
 # License AGPL-3.0 or later (https://www.gnu.org/licenses/agpl).
 
+from markupsafe import Markup
+
 from odoo import _, fields, models
 
 
@@ -36,7 +38,22 @@ def _process_response_message(self, response):
                 )
             )
             recipient._notify_typing(is_typing=False)
-            response["author_id"] = self.chatter_user_id.partner_id.id
-            response["message_type"] = "comment"
+            # Existing 18.0 bridges already return HTML as a plain str.
+            # message_post escapes str bodies and the Html field then wraps
+            # them, producing <p>&lt;p&gt;...&lt;/p&gt;</p>. body_is_html=True
+            # also warns for internal users, so convert to Markup instead of
+            # rewriting. Assume HTML by default; body_is_html=False opts out.
+            body = response.get("body") or ""
+            body_is_html = bool(response.pop("body_is_html", True))
+            if body_is_html and not isinstance(body, Markup):
+                body = Markup(body)
+            response.update(
+                {
+                    "author_id": self.chatter_user_id.partner_id.id,
+                    "body": body,
+                    "message_type": "comment",
+                    "subtype_xmlid": "mail.mt_comment",
+                }
+            )
 
         return super()._process_response_message(response)
diff --git a/ai_oca_bridge_chatter/tests/test_chatter.py b/ai_oca_bridge_chatter/tests/test_chatter.py
index 67b4eda1..f3287d4e 100644
--- a/ai_oca_bridge_chatter/tests/test_chatter.py
+++ b/ai_oca_bridge_chatter/tests/test_chatter.py
@@ -82,12 +82,82 @@ def test_chat(self):
                 body="Test message",
             )
             mock_post.assert_called_once()
-        self.assertEqual(
-            2,
-            self.env["mail.message"].search_count(
-                [("res_id", "=", self.chat.id), ("model", "=", "discuss.channel")]
-            ),
+        messages = self.env["mail.message"].search(
+            [("res_id", "=", self.chat.id), ("model", "=", "discuss.channel")],
+            order="id",
+        )
+        self.assertEqual(2, len(messages))
+        ai_message = messages[-1]
+        self.assertEqual(ai_message.author_id, self.ai_user.partner_id)
+        self.assertEqual(ai_message.message_type, "comment")
+        self.assertEqual(ai_message.subtype_id, self.env.ref("mail.mt_comment"))
+        self.assertIn("My message", ai_message.body)
+
+    def test_chat_html_body_is_comment(self):
+        """HTML replies stay Discuss comments and are not escaped as plaintext."""
+        with mock.patch("requests.post") as mock_post:
+            mock_post.return_value = mock.Mock(
+                status_code=200,
+                json=lambda: {"body": "<p>Hello! How can I help?</p>"},
+            )
+            self.chat.with_user(self.user.id).message_post(body="ola")
+        ai_message = self.env["mail.message"].search(
+            [
+                ("res_id", "=", self.chat.id),
+                ("model", "=", "discuss.channel"),
+                ("author_id", "=", self.ai_user.partner_id.id),
+            ],
+            limit=1,
+        )
+        self.assertTrue(ai_message)
+        self.assertEqual(ai_message.subtype_id, self.env.ref("mail.mt_comment"))
+        self.assertEqual(ai_message.message_type, "comment")
+        self.assertIn("Hello! How can I help?", ai_message.body)
+        self.assertIn("<p>Hello! How can I help?</p>", ai_message.body)
+        self.assertNotIn("<p>&lt;p&gt;", ai_message.body)
+
+    def test_chat_inline_html_body(self):
+        """Inline HTML that does not start with a tag is still posted as HTML."""
+        with mock.patch("requests.post") as mock_post:
+            mock_post.return_value = mock.Mock(
+                status_code=200,
+                json=lambda: {"body": "Hello <b>world</b>"},
+            )
+            self.chat.with_user(self.user.id).message_post(body="ola")
+        ai_message = self.env["mail.message"].search(
+            [
+                ("res_id", "=", self.chat.id),
+                ("model", "=", "discuss.channel"),
+                ("author_id", "=", self.ai_user.partner_id.id),
+            ],
+            limit=1,
+        )
+        self.assertTrue(ai_message)
+        self.assertIn("<b>world</b>", ai_message.body)
+        self.assertNotIn("&lt;b&gt;", ai_message.body)
+
+    def test_chat_body_is_html_false(self):
+        """body_is_html=False opts out of the 18.0 HTML default."""
+        with mock.patch("requests.post") as mock_post:
+            mock_post.return_value = mock.Mock(
+                status_code=200,
+                json=lambda: {
+                    "body": "<p>Hello! How can I help?</p>",
+                    "body_is_html": False,
+                },
+            )
+            self.chat.with_user(self.user.id).message_post(body="ola")
+        ai_message = self.env["mail.message"].search(
+            [
+                ("res_id", "=", self.chat.id),
+                ("model", "=", "discuss.channel"),
+                ("author_id", "=", self.ai_user.partner_id.id),
+            ],
+            limit=1,
         )
+        self.assertTrue(ai_message)
+        self.assertEqual(ai_message.subtype_id, self.env.ref("mail.mt_comment"))
+        self.assertIn("&lt;p&gt;", ai_message.body)
 
     def test_channel_not_called(self):
         """No AI bridge should be called when the user is not callend in the channel"""