diff --git a/nanobot/channels/matrix.py b/nanobot/channels/matrix.py
index 98926735e..dcece1043 100644
--- a/nanobot/channels/matrix.py
+++ b/nanobot/channels/matrix.py
@@ -3,6 +3,8 @@
 import asyncio
 import logging
 import mimetypes
+import time
+from dataclasses import dataclass
 from pathlib import Path
 from typing import Any, Literal, TypeAlias
 
@@ -28,8 +30,8 @@ try:
         RoomSendError,
         RoomTypingError,
         SyncError,
-        UploadError,
-    )
+        UploadError, RoomSendResponse,
+)
     from nio.crypto.attachments import decrypt_attachment
     from nio.exceptions import EncryptionError
 except ImportError as e:
@@ -97,6 +99,22 @@ MATRIX_HTML_CLEANER = nh3.Cleaner(
     link_rel="noopener noreferrer",
 )
 
+@dataclass
+class _StreamBuf:
+    """
+    Represents a buffer for managing LLM response stream data.
+
+    :ivar text: Stores the text content of the buffer.
+    :type text: str
+    :ivar event_id: Identifier for the associated event. None indicates no 
+        specific event association.
+    :type event_id: str | None
+    :ivar last_edit: Timestamp of the most recent edit to the buffer.
+    :type last_edit: float
+    """
+    text: str = ""
+    event_id: str | None = None
+    last_edit: float = 0.0
 
 def _render_markdown_html(text: str) -> str | None:
     """Render markdown to sanitized HTML; returns None for plain text."""
@@ -114,12 +132,36 @@ def _render_markdown_html(text: str) -> str | None:
     return formatted
 
 
-def _build_matrix_text_content(text: str) -> dict[str, object]:
-    """Build Matrix m.text payload with optional HTML formatted_body."""
+def _build_matrix_text_content(text: str, event_id: str | None = None) -> dict[str, object]:
+    """
+    Constructs and returns a dictionary representing the matrix text content with optional
+    HTML formatting and reference to an existing event for replacement. This function is 
+    primarily used to create content payloads compatible with the Matrix messaging protocol.
+
+    :param text: The plain text content to include in the message.
+    :type text: str
+    :param event_id: Optional ID of the event to replace. If provided, the function will 
+        include information indicating that the message is a replacement of the specified 
+        event.
+    :type event_id: str | None
+    :return: A dictionary containing the matrix text content, potentially enriched with 
+        HTML formatting and replacement metadata if applicable.
+    :rtype: dict[str, object]
+    """
     content: dict[str, object] = {"msgtype": "m.text", "body": text, "m.mentions": {}}
     if html := _render_markdown_html(text):
         content["format"] = MATRIX_HTML_FORMAT
         content["formatted_body"] = html
+    if event_id:
+        content["m.new_content"] =  {
+            "body": text,
+            "msgtype": "m.text"
+        }
+        content["m.relates_to"] = {
+            "rel_type": "m.replace",
+            "event_id": event_id
+        }
+
     return content
 
 
@@ -159,7 +201,8 @@ class MatrixConfig(Base):
     allow_from: list[str] = Field(default_factory=list)
     group_policy: Literal["open", "mention", "allowlist"] = "open"
     group_allow_from: list[str] = Field(default_factory=list)
-    allow_room_mentions: bool = False
+    allow_room_mentions: bool = False,
+    streaming: bool = False
 
 
 class MatrixChannel(BaseChannel):
@@ -167,6 +210,8 @@ class MatrixChannel(BaseChannel):
 
     name = "matrix"
     display_name = "Matrix"
+    _STREAM_EDIT_INTERVAL = 2 # min seconds between edit_message_text calls
+    monotonic_time = time.monotonic
 
     @classmethod
     def default_config(cls) -> dict[str, Any]:
@@ -192,6 +237,8 @@ class MatrixChannel(BaseChannel):
         )
         self._server_upload_limit_bytes: int | None = None
         self._server_upload_limit_checked = False
+        self._stream_bufs: dict[str, _StreamBuf] = {}
+
 
     async def start(self) -> None:
         """Start Matrix client and begin sync loop."""
@@ -297,14 +344,17 @@ class MatrixChannel(BaseChannel):
         room = getattr(self.client, "rooms", {}).get(room_id)
         return bool(getattr(room, "encrypted", False))
 
-    async def _send_room_content(self, room_id: str, content: dict[str, Any]) -> None:
+    async def _send_room_content(self, room_id: str,
+                                 content: dict[str, Any]) -> None | RoomSendResponse | RoomSendError:
         """Send m.room.message with E2EE options."""
         if not self.client:
-            return
+            return None
         kwargs: dict[str, Any] = {"room_id": room_id, "message_type": "m.room.message", "content": content}
+
         if self.config.e2ee_enabled:
             kwargs["ignore_unverified_devices"] = True
-        await self.client.room_send(**kwargs)
+        response = await self.client.room_send(**kwargs)
+        return response
 
     async def _resolve_server_upload_limit_bytes(self) -> int | None:
         """Query homeserver upload limit once per channel lifecycle."""
@@ -414,6 +464,47 @@ class MatrixChannel(BaseChannel):
             if not is_progress:
                 await self._stop_typing_keepalive(msg.chat_id, clear_typing=True)
 
+    async def send_delta(self, chat_id: str, delta: str, metadata: dict[str, Any] | None = None) -> None:
+        meta = metadata or {}
+        relates_to = self._build_thread_relates_to(metadata)
+
+        if meta.get("_stream_end"):
+            buf = self._stream_bufs.pop(chat_id, None)
+            if not buf or not buf.event_id or not buf.text:
+                return
+
+            await self._stop_typing_keepalive(chat_id, clear_typing=True)
+            
+            content = _build_matrix_text_content(buf.text, buf.event_id)
+            if relates_to:
+                content["m.relates_to"] = relates_to
+            await self._send_room_content(chat_id, content)
+            return
+
+        buf = self._stream_bufs.get(chat_id)
+        if buf is None:
+            buf = _StreamBuf()
+            self._stream_bufs[chat_id] = buf
+        buf.text += delta
+    
+        if not buf.text.strip():
+            return
+
+        now = self.monotonic_time()
+
+        if not buf.last_edit or (now - buf.last_edit) >= self._STREAM_EDIT_INTERVAL:
+            try:
+                content = _build_matrix_text_content(buf.text, buf.event_id)
+                response = await self._send_room_content(chat_id, content)
+                buf.last_edit = now
+                if not buf.event_id:
+                    # we are editing the same message all the time, so only the first time the event id needs to be set
+                    buf.event_id = response.event_id
+            except Exception:
+                await self._stop_typing_keepalive(metadata["room_id"], clear_typing=True)
+                pass
+
+
     def _register_event_callbacks(self) -> None:
         self.client.add_event_callback(self._on_message, RoomMessageText)
         self.client.add_event_callback(self._on_media_message, MATRIX_MEDIA_EVENT_FILTER)
diff --git a/tests/channels/test_matrix_channel.py b/tests/channels/test_matrix_channel.py
index dd5e97d90..3ad65e76b 100644
--- a/tests/channels/test_matrix_channel.py
+++ b/tests/channels/test_matrix_channel.py
@@ -3,6 +3,9 @@ from pathlib import Path
 from types import SimpleNamespace
 
 import pytest
+from nio import RoomSendResponse
+
+from nanobot.channels.matrix import _build_matrix_text_content
 
 # Check optional matrix dependencies before importing
 try:
@@ -65,6 +68,7 @@ class _FakeAsyncClient:
         self.raise_on_send = False
         self.raise_on_typing = False
         self.raise_on_upload = False
+        self.room_send_response: RoomSendResponse | None = RoomSendResponse(event_id="", room_id="")
 
     def add_event_callback(self, callback, event_type) -> None:
         self.callbacks.append((callback, event_type))
@@ -87,7 +91,7 @@ class _FakeAsyncClient:
         message_type: str,
         content: dict[str, object],
         ignore_unverified_devices: object = _ROOM_SEND_UNSET,
-    ) -> None:
+    ) -> RoomSendResponse:
         call: dict[str, object] = {
             "room_id": room_id,
             "message_type": message_type,
@@ -98,6 +102,7 @@ class _FakeAsyncClient:
         self.room_send_calls.append(call)
         if self.raise_on_send:
             raise RuntimeError("send failed")
+        return self.room_send_response
 
     async def room_typing(
         self,
@@ -520,6 +525,7 @@ async def test_on_message_room_mention_requires_opt_in() -> None:
         source={"content": {"m.mentions": {"room": True}}},
     )
 
+    channel.config.allow_room_mentions = False
     await channel._on_message(room, room_mention_event)
     assert handled == []
     assert client.typing_calls == []
@@ -1322,3 +1328,220 @@ async def test_send_keeps_plaintext_only_for_plain_text() -> None:
         "body": text,
         "m.mentions": {},
     }
+
+
+def test_build_matrix_text_content_basic_text() -> None:
+    """Test basic text content without HTML formatting."""
+    result = _build_matrix_text_content("Hello, World!")
+    expected = {
+        "msgtype": "m.text",
+        "body": "Hello, World!",
+        "m.mentions": {}
+    }
+    assert expected == result
+
+
+def test_build_matrix_text_content_with_markdown() -> None:
+    """Test text content with markdown that renders to HTML."""
+    text = "*Hello* **World**"
+    result = _build_matrix_text_content(text)
+    assert "msgtype" in result
+    assert "body" in result
+    assert result["body"] == text
+    assert "format" in result
+    assert result["format"] == "org.matrix.custom.html"
+    assert "formatted_body" in result
+    assert isinstance(result["formatted_body"], str)
+    assert len(result["formatted_body"]) > 0
+
+
+def test_build_matrix_text_content_with_event_id() -> None:
+    """Test text content with event_id for message replacement."""
+    event_id = "$8E2XVyINbEhcuAxvxd1d9JhQosNPzkVoU8TrbCAvyHo"
+    result = _build_matrix_text_content("Updated message", event_id)
+    assert "msgtype" in result
+    assert "body" in result
+    assert result["m.new_content"]
+    assert result["m.new_content"]["body"] == "Updated message"
+    assert result["m.relates_to"]["rel_type"] == "m.replace"
+    assert result["m.relates_to"]["event_id"] == event_id
+
+
+def test_build_matrix_text_content_no_event_id() -> None:
+    """Test that when event_id is not provided, no extra properties are added."""
+    result = _build_matrix_text_content("Regular message")
+
+    # Basic required properties should be present
+    assert "msgtype" in result
+    assert "body" in result
+    assert result["body"] == "Regular message"
+
+    # Extra properties for replacement should NOT be present
+    assert "m.relates_to" not in result
+    assert "m.new_content" not in result
+    assert "format" not in result
+    assert "formatted_body" not in result
+
+
+def test_build_matrix_text_content_plain_text_no_html() -> None:
+    """Test plain text that should not include HTML formatting."""
+    result = _build_matrix_text_content("Simple plain text")
+    assert "msgtype" in result
+    assert "body" in result
+    assert "format" not in result
+    assert "formatted_body" not in result
+
+
+@pytest.mark.asyncio
+async def test_send_room_content_returns_room_send_response():
+    """Test that _send_room_content returns the response from client.room_send."""
+    client = _FakeAsyncClient("", "", "", None)
+    channel = MatrixChannel(_make_config(), MessageBus())
+    channel.client = client
+
+    room_id = "!test_room:matrix.org"
+    content = {"msgtype": "m.text", "body": "Hello World"}
+
+    result = await channel._send_room_content(room_id, content)
+
+    assert result is client.room_send_response
+
+
+@pytest.mark.asyncio
+async def test_send_delta_creates_stream_buffer_and_sends_initial_message() -> None:
+    channel = MatrixChannel(_make_config(), MessageBus())
+    client = _FakeAsyncClient("", "", "", None)
+    channel.client = client
+    client.room_send_response.event_id = "$8E2XVyINbEhcuAxvxd1d9JhQosNPzkVoU8TrbCAvyHo"
+
+    await channel.send_delta("!room:matrix.org", "Hello")
+
+    assert "!room:matrix.org" in channel._stream_bufs
+    buf = channel._stream_bufs["!room:matrix.org"]
+    assert buf.text == "Hello"
+    assert buf.event_id == "$8E2XVyINbEhcuAxvxd1d9JhQosNPzkVoU8TrbCAvyHo"
+    assert len(client.room_send_calls) == 1
+    assert client.room_send_calls[0]["content"]["body"] == "Hello"
+
+
+@pytest.mark.asyncio
+async def test_send_delta_appends_without_sending_before_edit_interval(monkeypatch) -> None:
+    channel = MatrixChannel(_make_config(), MessageBus())
+    client = _FakeAsyncClient("", "", "", None)
+    channel.client = client
+    client.room_send_response.event_id = "$8E2XVyINbEhcuAxvxd1d9JhQosNPzkVoU8TrbCAvyHo"
+
+    now = 100.0
+    monkeypatch.setattr(channel, "monotonic_time", lambda: now)
+
+    await channel.send_delta("!room:matrix.org", "Hello")
+    assert len(client.room_send_calls) == 1
+
+    await channel.send_delta("!room:matrix.org", " world")
+    assert len(client.room_send_calls) == 1
+
+    buf = channel._stream_bufs["!room:matrix.org"]
+    assert buf.text == "Hello world"
+    assert buf.event_id == "$8E2XVyINbEhcuAxvxd1d9JhQosNPzkVoU8TrbCAvyHo"
+
+
+@pytest.mark.asyncio
+async def test_send_delta_edits_again_after_interval(monkeypatch) -> None:
+    channel = MatrixChannel(_make_config(), MessageBus())
+    client = _FakeAsyncClient("", "", "", None)
+    channel.client = client
+    client.room_send_response.event_id = "$8E2XVyINbEhcuAxvxd1d9JhQosNPzkVoU8TrbCAvyHo"
+
+    times = [100.0, 102.0, 104.0, 106.0, 108.0]
+    times.reverse()
+    monkeypatch.setattr(channel, "monotonic_time", lambda: times and times.pop())
+
+    await channel.send_delta("!room:matrix.org", "Hello")
+    await channel.send_delta("!room:matrix.org", " world")
+
+    assert len(client.room_send_calls) == 2
+    first_content = client.room_send_calls[0]["content"]
+    second_content = client.room_send_calls[1]["content"]
+
+    assert "body" in first_content
+    assert first_content["body"] == "Hello"
+    assert "m.relates_to" not in first_content
+
+    assert "body" in second_content
+    assert "m.relates_to" in second_content
+    assert second_content["body"] == "Hello world"
+    assert second_content["m.relates_to"] == {
+        "rel_type": "m.replace",
+        "event_id": "$8E2XVyINbEhcuAxvxd1d9JhQosNPzkVoU8TrbCAvyHo",
+    }
+
+
+@pytest.mark.asyncio
+async def test_send_delta_stream_end_replaces_existing_message() -> None:
+    channel = MatrixChannel(_make_config(), MessageBus())
+    client = _FakeAsyncClient("", "", "", None)
+    channel.client = client
+
+    channel._stream_bufs["!room:matrix.org"] = matrix_module._StreamBuf(
+        text="Final text",
+        event_id="event-1",
+        last_edit=100.0,
+    )
+
+    await channel.send_delta("!room:matrix.org", "", {"_stream_end": True})
+
+    assert "!room:matrix.org" not in channel._stream_bufs
+    assert client.typing_calls[-1] == ("!room:matrix.org", False, TYPING_NOTICE_TIMEOUT_MS)
+    assert len(client.room_send_calls) == 1
+    assert client.room_send_calls[0]["content"]["body"] == "Final text"
+    assert client.room_send_calls[0]["content"]["m.relates_to"] == {
+        "rel_type": "m.replace",
+        "event_id": "event-1",
+    }
+
+
+@pytest.mark.asyncio
+async def test_send_delta_stream_end_noop_when_buffer_missing() -> None:
+    channel = MatrixChannel(_make_config(), MessageBus())
+    client = _FakeAsyncClient("", "", "", None)
+    channel.client = client
+
+    await channel.send_delta("!room:matrix.org", "", {"_stream_end": True})
+
+    assert client.room_send_calls == []
+    assert client.typing_calls == []
+
+
+@pytest.mark.asyncio
+async def test_send_delta_on_error_stops_typing(monkeypatch) -> None:
+    channel = MatrixChannel(_make_config(), MessageBus())
+    client = _FakeAsyncClient("", "", "", None)
+    client.raise_on_send = True
+    channel.client = client
+
+    now = 100.0
+    monkeypatch.setattr(channel, "monotonic_time", lambda: now)
+
+    await channel.send_delta("!room:matrix.org", "Hello", {"room_id": "!room:matrix.org"})
+
+    assert "!room:matrix.org" in channel._stream_bufs
+    assert channel._stream_bufs["!room:matrix.org"].text == "Hello"
+    assert len(client.room_send_calls) == 1
+    
+    assert len(client.typing_calls) == 1
+
+
+@pytest.mark.asyncio
+async def test_send_delta_ignores_whitespace_only_delta(monkeypatch) -> None:
+    channel = MatrixChannel(_make_config(), MessageBus())
+    client = _FakeAsyncClient("", "", "", None)
+    channel.client = client
+
+    now = 100.0
+    monkeypatch.setattr(channel, "monotonic_time", lambda: now)
+
+    await channel.send_delta("!room:matrix.org", "   ")
+
+    assert "!room:matrix.org" in channel._stream_bufs
+    assert channel._stream_bufs["!room:matrix.org"].text == "   "
+    assert client.room_send_calls == []
\ No newline at end of file