Using Socket Mode

With the introduction of Socket Mode, Bolt for Python introduced support in version 1.2.0. With Socket Mode, instead of creating a server with endpoints that Slack sends payloads too, the app will instead connect to Slack via a WebSocket connection and receive data from Slack over the socket connection. Make sure to enable Socket Mode in your app configuration settings.

To use the Socket Mode, add SLACK_APP_TOKEN as an environment variable. You can get your App Token in your app configuration settings under the Basic Information section.

While we recommend using the built-in Socket Mode adapter, there are a few other 3rd party library based implementations. Here is the list of available adapters.

PyPI Project	Bolt Adapter
slack_sdk	slack_bolt.adapter.socket_mode
websocket_client	slack_bolt.adapter.socket_mode.websocket_client
aiohttp (asyncio-based)	slack_bolt.adapter.socket_mode.aiohttp
websockets (asyncio-based)	slack_bolt.adapter.socket_mode.websockets

import os
from slack_bolt import App
from slack_bolt.adapter.socket_mode import SocketModeHandler

# Install the Slack app and get xoxb- token in advance
app = App(token=os.environ["SLACK_BOT_TOKEN"])

# Add middleware / listeners here

if __name__ == "__main__":
    # export SLACK_APP_TOKEN=xapp-***
    # export SLACK_BOT_TOKEN=xoxb-***
    handler = SocketModeHandler(app, os.environ["SLACK_APP_TOKEN"])
    handler.start()

Using Async (asyncio)

To use the asyncio-based adapters such as aiohttp, your whole app needs to be compatible with asyncio's async/await programming model. AsyncSocketModeHandler is available for running AsyncApp and its async middleware and listeners.

To learn how to use AsyncApp, checkout the using Async document and relevant examples.

from slack_bolt.app.async_app import AsyncApp
# The default is the aiohttp based implementation
from slack_bolt.adapter.socket_mode.async_handler import AsyncSocketModeHandler

app = AsyncApp(token=os.environ["SLACK_BOT_TOKEN"])

# Add middleware / listeners here

async def main():
    handler = AsyncSocketModeHandler(app, os.environ["SLACK_APP_TOKEN"])
    await handler.start_async()

if __name__ == "__main__":
    import asyncio
    asyncio.run(main())