Slack notifications

[MaxMyzer]

This might actually be a bug in the slack integration, but I wanted to ask here if I was doing something wrong first.

You can send a slack notification like this:

action: notify.my_slack_service
data: 
  target: 
    - my_slack_channel_name_or_id
  message: "hello, world!"

where my_slack_channel_name_or_id is either a literal channel name (like #general) or a channel id (like A20H2AN55DX). This behavior works as intended.

Using SuperNotify, I have my configuration containing these lines:

recipients:
  - person: person.my_user
    delivery:
      slack:
        target: A20H2AN55DX
delivery:
  slack:
      transport: generic
      action: notify.my_slack_service

Which I test using this action to force it to attempt a slack delivery:

action: notify.supernotifyer
data: 
  target: person.my_user
  message: test message
  data:
    delivery:
      slack:
        enabled: true
        # target: A20H2AN55DX

Note: I previously was testing specifying the target in the action instead to see if it fixed the issue, which it did not.

Doing this results in an error from the slack integration:

ERROR (MainThread) [homeassistant.components.slack.notify] There was a Slack API error while sending to "A20H2AN55DX": SlackApiError("The request to the Slack API failed. (url: https://slack.com/api/chat.postMessage, status: 200)\nThe server responded with: {'ok': False, 'error': 'channel_not_found'}")

Is there something I am missing here with my call through supernotify, or is this a bug in the slack integration?

[jeyrb]

Does it work if you call the slack notify from Developer Tools action tab with the same data?

Couple of things I changed in config to make it pass the channel all the way down ( some of which the code will be kinder with in future, so less need to tweak config ). With this didn't need the enabled or the channel in the notification call.

recipients:
  - person: person.my_user
    delivery:
      slack:
        target: 
           slack_channel: A20H2AN55DX
delivery:
  slack:
      transport: generic
      action: notify.my_slack_service
      options:
           target_categories: slack_channel

what's happening here is that there's a general _UNKNOWN_ bucket for custom integration targets, versus the usual entity_id etc. My config is defining a new category slack_channel ( you could call it anything ) for the person, and then asking the slack delivery to only use that target. This also means that if you had Telegram or Discord or whatever they could all be nicely bucketed separately.

The odd thing however is that your error message looks like the right target is getting to the Slack integration and being rejected there. That's why calling straight from Developer Tools good - it isolates the problem as Slack or Supernotify.

You could also put debug: true onto the delivery config - this will mean the slack call isn't fire and forget and Supernotify will wait for a response and archive that with the notification debug info

[MaxMyzer]

Does it work if you call the slack notify from Developer Tools action tab with the same data?

If you mean directly calling notify.my_slack_service, yes. All of the calls I have been doing are from the developer tools action pane. I changed my config to match what you show here (and added debug: true, however no data was returned or is in the error log.
I also attempted to do

action: notify.supernotifyer
data: 
  message: hello?
  data:
    delivery:
      mobile_push:
        enabled: false
      slack:
        enabled: true
        data:
          options: 
            target_categories: A20H2AN55DX

to force the same result as the config, in case something was wrong, and got 2025-12-18 18:41:59.515 WARNING (MainThread) [custom_components.supernotify.notify] SUPERNOTIFY No deliveries made for 872463fe-dc73-11f0-9208-52540002463b: No delivery envelopes generated in the log.

If I use the provided config and call supernotify as I have before, I get the same error as before.

[jeyrb]

target_categories should be the name of the category, not the actual ID.

With the config I had above, the notification would be

action: notify.supernotifyer
data: 
  message: hello?
  data:
    delivery:
      mobile_push:
        enabled: false
      slack:
         enabled: true

or you could override at action call

action: notify.supernotifyer
data: 
  message: hello?
  data:
    target:
      slack_channel: A20H2AN55DX

and the slack delivery would get picked because it has a matching target.

I have the archiving switched on all the time, and that way the archived notification with all the debug info is available, including the exact call made to the service. I use the Studio Code Server add-in to view them, or mount the config as a network drive. You can also get it via a Home Assistant action - supernotifier.last_notification

There's a beta release that improves the target selection, v1.5.4-beta1 and the docs page for generic transport now has more help for this.

[MaxMyzer]

recipients:
  - person: person.my_user
     delivery:
      slack: 
        enabled: true # I confused `enabled`'s functionality. Setting this to `false` does NOT get overridden by a action! Should use `selection: explicit`
        target: 
          slack_channel: 
            - A20H2AN55DX
            - #my_channel
delivery:
  slack:
    debug: true
    transport: generic
    action: notify.my_slack_service
    options:
      target_categories: slack_channel

action: notify.supernotifyer
data: 
  message: "perhaps this will work?"
  data:
    delivery:
      mobile_push:
        enabled: false
      slack:
        enabled: true

Thanks for the help!