Sending Messages
Sending messages is a core part of an agent's functionality. With all activity handlers, a send method is provided which allows your handlers to send a message back to the user to the relevant conversation.
@app.on_message
async def handle_message(ctx: ActivityContext[MessageActivity]):
await ctx.send(f"You said '{ctx.activity.text}'")
In the above example, the handler gets a message activity, and uses the send method to send a reply to the user.
@app.event("sign_in")
async def handle_sign_in(event: SignInEvent):
"""Handle sign-in events."""
await event.activity_ctx.send("You are now signed in!")
You are not restricted to only replying to message activities. In the above example, the handler is listening to sign_in events, which are sent when a user successfully signs in.
This shows an example of sending a text message. Additionally, you are able to send back things like adaptive cards by using the same send method. Look at the adaptive card section for more details.
Streaming​
You may also stream messages to the user which can be useful for long messages, or AI generated messages. The SDK makes this simple for you by providing a stream function which you can use to send messages in chunks.
@app.on_message
async def handle_message(ctx: ActivityContext[MessageActivity]):
ctx.stream.update("Stream starting...")
await asyncio.sleep(1)
# Stream messages with delays using ctx.stream.emit
for message in STREAM_MESSAGES:
# Add some randomness to timing
await asyncio.sleep(random())
ctx.stream.emit(message)
Streaming is currently only supported in 1:1 conversations, not group chats or channels

@Mention​
Sending a message at @mentions a user is as simple including the details of the user using the add_mention method
@app.on_message
async def handle_message(ctx: ActivityContext[MessageActivity]):
await ctx.send(MessageActivityInput(text='hi!').add_mention(account=ctx.activity.from_))