Currently, if a channel has a workflow that is used to post a message to the channel, these messages are not detected or passed to the application with the current APIs.
In preliminary testing, messages do not show up with any of the current events. It's unclear if this is supported by the RTM API at all or how the normal Slack clients learns about such events, as so far I haven't noticed any relevant network traffic (e.g. on the WebSocket) when a message is posted via workflow.
Obviously, the client learns about it somehow so we need to figure that out.
You must be
7/30/2025 11:53 AM — InterLinked
It does not appear there is a solution to this within the RTM library. The solution I have implemented in a program using this library is simply to poll the channel once per second for new messages, and process them. Not the most bandwidth efficient approach, but Slack can go pound sand.