diff --git a/rocketchat_API/APISections/chat.py b/rocketchat_API/APISections/chat.py
index 1df28c0..9544f7a 100644
--- a/rocketchat_API/APISections/chat.py
+++ b/rocketchat_API/APISections/chat.py
@@ -5,21 +5,56 @@
 class RocketChatChat(RocketChatBase):
     def chat_post_message(self, text, room_id=None, channel=None, **kwargs):
         """Posts a new chat message."""
-        if room_id:
-            if text:
-                return self.call_api_post(
-                    "chat.postMessage", roomId=room_id, text=text, kwargs=kwargs
-                )
-            return self.call_api_post("chat.postMessage", roomId=room_id, kwargs=kwargs)
+        if not (channel or room_id):
+            raise RocketMissingParamException("roomId or channel required")
+
+        text = "" if text is None else text
+
+        payload = {"text": text, **kwargs}
         if channel:
-            if text:
-                return self.call_api_post(
-                    "chat.postMessage", channel=channel, text=text, kwargs=kwargs
-                )
-            return self.call_api_post(
-                "chat.postMessage", channel=channel, kwargs=kwargs
-            )
-        raise RocketMissingParamException("roomId or channel required")
+            payload["channel"] = channel
+        if room_id:
+            payload["roomId"] = room_id
+
+        self._sanitize_payload_text_fields(payload)
+
+        return self.call_api_post("chat.postMessage", kwargs=payload)
+
+    @staticmethod
+    def _sanitize_text(value: str) -> str:
+        """Return value with common double-escaped control sequences normalized."""
+        if not isinstance(value, str):
+            return value
+        return (
+            value.replace("\\n", "\n")
+            .replace("\\r", "\r")
+            .replace("\\t", "\t")
+            .replace("\\b", "\b")
+            .replace("\\f", "\f")
+        )
+
+    @staticmethod
+    def _sanitize_payload_text_fields(payload: dict) -> dict:
+        """
+        In-place sanitize of typical text fields in chat payloads:
+        - payload["text"]
+        - payload["attachments"][i]["text"]
+
+        Returns the mutated payload for convenience.
+        """
+        if not isinstance(payload, dict):
+            return payload
+
+        if "text" in payload and isinstance(payload["text"], str):
+            payload["text"] = RocketChatChat._sanitize_text(payload["text"])
+
+        attachments = payload.get("attachments")
+        if isinstance(attachments, list):
+            for att in attachments:
+                if isinstance(att, dict) and isinstance(att.get("text"), str):
+                    att["text"] = RocketChatChat._sanitize_text(att["text"])
+
+        return payload
 
     def chat_send_message(self, message):
         if "rid" in message:
diff --git a/tests/test_chat.py b/tests/test_chat.py
index 1dc3684..eb39082 100644
--- a/tests/test_chat.py
+++ b/tests/test_chat.py
@@ -227,3 +227,41 @@ def test_chat_get_mentioned_messages(logged_rocket):
     assert "messages" in chat_get_mentioned_messages
     assert len(chat_get_mentioned_messages.get("messages")) > 0
     assert chat_get_mentioned_messages.get("messages")[0].get("msg") == "hello @user1"
+
+
+def test_chat_post_sanitizes_text_and_attachments(logged_rocket):
+    # message text contains double-escaped sequences
+    msg_text = "hello\\nworld\\t!"
+    att_text = "line1\\nline2"
+
+    chat_post_message = logged_rocket.chat_post_message(
+        msg_text,
+        channel="GENERAL",
+        attachments=[{"color": "#00ff00", "text": att_text}],
+    ).json()
+
+    assert chat_post_message.get("success")
+    mid = chat_post_message["message"]["_id"]
+
+    # retrieve and verify that sequences became real control chars
+    got = logged_rocket.chat_get_message(msg_id=mid).json()
+    assert got.get("success")
+
+    posted = got["message"]
+    assert posted["msg"] == "hello\nworld\t!"
+    assert posted["attachments"][0]["text"] == "line1\nline2"
+
+
+def test_chat_update_sanitizes_text(logged_rocket):
+    # create a message first
+    mid = (
+        logged_rocket.chat_post_message("seed", channel="GENERAL")
+        .json()["message"]["_id"]
+    )
+    # update with escaped content
+    upd = logged_rocket.chat_update(
+        room_id="GENERAL", msg_id=mid, text="foo\\nbar"
+    ).json()
+    assert upd.get("success")
+    assert upd["message"]["msg"] == "foo\nbar"
+