API-2 failed to solve the problem and the API configuration of Jira does not allow for reopening or declining the solution. The need is to reflect priority changes only to slack. This allows for creating an escalation channel. Ideally I'd like to be able to choose the priority level. So I want reflected any changes to/from a P0 priority. I understand this seems like a very specific request, but every development organization has the notion of escalations and integrating those with slack is a very useful workflow. Some limited version of this can be achieved with Jira workflow using transitions and status, but it disrupts normal workflow status.