On the wire
Ships with HTTP status 409, carrying "code": "RU-3015" in the response body alongside the human-readable error message. Existing fields are never replaced by the code: it is additive.
Common causes
- An automated setup running against an account where Slack alerts were already set up by a person.
- Re-running a setup with a new webhook URL.
How to fix it
- Keep the existing webhook: read it with GET /notification-channels and skip this step.
- Or remove it with DELETE /notification-channels/slack, then create the new one.
Related codes
- RU-3007: Invalid notification channel request
Still stuck?
Ask support and mention RU-3015: the code pins down the exact refusal path, so you skip the diagnostic back-and-forth.