Atlassian
There are several cases for making an HTTP request from a host application to another Atlassian application.
For example:
- Create a Confluence space when a Jira project is created
- Automatically create Confluence pages for certain types of issues
- Create release notes when a Jira version is released
- Automatically decline a pull request when the associated Jira issue is closed as Won't Fix
Typically these are done through calls to the REST API of the other application, or to a script endpoint. However, you can also use remote control to do the same thing.
Which approach you use depends on the specifics of the task in hand.