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.
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