Any news on this? This feature would be quite helpful in federated clusters and for any kind of automation involving downtimes and other changes which should be announced properly.

https://github.com/nextcloud/announcementcenter#%EF%B8%8F-state-of-maintenance

If you manage to run a federated cluster maybe you could also sponsor a feature development?

Thanks for the info, I totally overlooked that... I currently evaluate whether Nextcloud is feasable for our use case with up to 30k users. I imagine the announcement center being really useful for things like ToS and maintenance announcements, so one has not to build and rely on other communication infrastructures. If we want to move on with this project, we will approach your company and we will definately consider your suggestion!

as a workaround you might use the rest api here and post at /api/v1/announcements, but you'll need an admin session.
But I agree, a CLI would be nice, I'll check this out next PR!

According to https://docs.nextcloud.com/server/latest/developer_manual/server/externalapi.html#authentication-basics this should work

curl -X POST \
  -H "Content-Type: application/json" \
  --header "OCS-APIRequest: true" \
  -u adminUser:appToken \
  -d '{
    "subject": "Your Subject",
    "message": "Your Markdown Body",
    "plainMessage": "Your Plain Body",
    "groups": ["group1", "group2"],
    "activities": true,
    "notifications": true,
    "emails": true,
    "comments": true,
    "banner": true,
    "scheduleTime": null,
    "deleteTime": null
  }' \
  https://127.0.0.1/ocs/v2.php/apps/announcementcenter/api/v1/announcements?format=json

You might need to remove scheduleTime and deleteTime in your version

I tested this:

{"ocs":{"meta":{"status":"ok","statuscode":200,"message":"OK"},"data":{"id":24,"author_id":"nextcloud27","author":"nextcloud27","time":1710863883,"subject":"Your Subject","message":"Your Markdown Body","groups":[{"id":"everyone","name":"everyone"}],"comments":0,"schedule_time":null,"delete_time":null,"notifications":true}}}