adds streams

Author: lukegalbraithrussell

docs/english/concepts/message-sending.md

@@ -5,6 +5,7 @@ Within your listener function, `say()` is available whenever there is an associa
 In the case that you'd like to send a message outside of a listener or you want to do something more advanced (like handle specific errors), you can call `client.chat_postMessage` [using the client attached to your Bolt instance](/tools/bolt-python/concepts/web-api).
 
 Refer to [the module document](https://docs.slack.dev/tools/bolt-python/reference/kwargs_injection/args.html) to learn the available listener arguments.
+
 ```python
 # Listens for messages containing "knock knock" and responds with an italicized "who's there?"
 @app.message("knock knock")
@@ -38,4 +39,100 @@ def show_datepicker(event, say):
             blocks=blocks,
             text="Pick a date for me to remind you"
         )
+```
+
+## Streaming messages 
+
+You can have your app's messages stream in for those AI chatbot vibes. This is done through three methods:
+
+* `chat_startStream`
+* `chat_appendStream`
+* `chat_stopStream`
+
+### Starting the message stream
+
+First you need to begin the message stream.
+
+```python
+# Example: Stream a response to any message
+@app.message()
+def handle_message(message, client):
+    channel_id = payload["channel"]
+    thread_ts = payload["thread_ts"]
+    
+    # Start a new message stream
+    stream_response = client.chat_startStream(
+        channel=channel_id,
+        thread_ts=thread_ts,
+    )
+    stream_ts = stream_response["ts"]
+```
+
+### Appending content to the message stream
+
+With the stream started, you can then append text to it in chunks to convey a streaming effect.
+
+The structure of the text coming in will depend on your source. The following code snippet uses OpenAI's response structure as an example. 
+
+```python
+# continued from above
+    for event in returned_message:
+        if event.type == "response.output_text.delta":
+            client.chat_appendStream(
+                channel=channel_id, 
+                ts=stream_ts, 
+                markdown_text=f"{event.delta}"
+            )
+        else:
+            continue
+```
+
+### Finishing the message stream
+
+Your app can then end the stream with the `chat_stopStream` method. 
+
+```python
+# continued from above
+    client.chat_stopStream(
+        channel=channel_id, 
+        ts=stream_ts
+    )
+```
+
+The method also provides you an opportunity to request user feedback on your app's responses using the [feedback buttons](/reference/block-kit/block-elements/feedback-buttons-element) block element within the [context actions](/reference/block-kit/blocks/context-actions-block) block. The user will be presented with thumbs up and thumbs down buttons
+
+```python
+def create_feedback_block() -> List[Block]:
+    blocks: List[Block] = [
+        ContextActionsBlock(
+            elements=[
+                FeedbackButtonsElement(
+                    action_id="feedback",
+                    positive_button=FeedbackButtonObject(
+                        text="Good Response",
+                        accessibility_label="Submit positive feedback on this response",
+                        value="good-feedback",
+                    ),
+                    negative_button=FeedbackButtonObject(
+                        text="Bad Response",
+                        accessibility_label="Submit negative feedback on this response",
+                        value="bad-feedback",
+                    ),
+                )
+            ]
+        )
+    ]
+    return blocks
+
+@app.message()
+def handle_message(message, client):
+    # ... previous streaming code ...
+    
+    # Stop the stream and add interactive elements
+    feedback_block = create_feedback_block()
+    client.chat_stopStream(
+        channel=channel_id, 
+        ts=stream_ts, 
+        blocks=feedback_block
+    )
 ```