Unable to read message received in a Slack channel using python slack bolt SDK

Question

I'm trying to read messages posted in a private Slack channel using Slack Bolt Python SDK. The problem is that the method is not getting invoked at all when I post some messages to this channel.

from typing import Optional
import slack_sdk
import os
import logging
from pathlib import Path
from dotenv import load_dotenv
from slack_bolt import App
from slack_bolt.adapter.socket_mode import SocketModeHandler

logging.basicConfig(level=logging.DEBUG)
env_path = Path('..') / '.env'
load_dotenv(dotenv_path=env_path)

SLACK_VERIFICATION_TOKEN = os.environ['SLACK_VERIFICATION_TOKEN']
SLACK_SIGNING_SECRET = os.environ['SLACK_SIGNING_SECRET']
SLACK_BOT_TOKEN = os.environ['SLACK_BOT_TOKEN']
SLACK_APP_TOKEN = os.environ['SLACK_APP_TOKEN']

app = App(token=SLACK_BOT_TOKEN, signing_secret=SLACK_SIGNING_SECRET)

@app.message("<Slack Channel Id>")  # Replace "your-channel-id" with your actual channel ID
 def handle_message(message, say):
     user = message["user"]
     text = message["text"]
     channel = message["channel"]

     # Do something with the received message
     print(f"Received message '{text}' from user {user} in channel {channel}")


if __name__ == "__main__":
    handler = SocketModeHandler(app, SLACK_APP_TOKEN)
    handler.start()

I have enabled subscriptions as well to events as message.channels event

Answer 1

To receive messages from a private channel, you'll need to ensure a few key things are in place:

1. Permissions: Make sure the user (in this case, your bot or app) has the necessary permissions to access the channel's history. This involves having the channels:history or groups:history permissions granted to your bot's API token or user account to read messages in private channel.

2. Membership in the Channel: Your bot or app needs to be added or invited to the private channel. Since it's a private channel, access is restricted, and only approved members or bots can join. Ensure your bot has been installed or added to the private channel.