My concerns are about question which i got from other side when i send them invitation trying to create new link to partner's JIRA.
This question was what was this link for. I realised that I don't know how to explain them purpose of this link and if there is any issue with the security in case when they accept my invitation. Especially if any exclusive user of our JIRA could have view to their part.
I need this functionallity to have better links to their JIRA issues from out confluence pages using widget.
Thanks in advance for any advice.
When you create an application link in Atlassian products, this allows the two applications to communicate with each other. However when you only setup a one-way link (not reciprocal links) this limits which application can make requests of the other.
In a reciprocal setup, both applications can communicate with each other equally. However say you have a Jira -> Confluence link setup only. In that setup, Jira can make a web call to confluence to find pages where say a Jira issue key is mentioned. But confluence can't make calls directly to the Jira application. So functionality like using a Jira Macro on a confluence page to show a Jira issues or a list of Jira search results won't be possible in that setup. This is also explained a bit more in Link Atlassian applications to work together.
I would not be too concerned about the security aspects here. The application link is just making it easier for user accounts that have access to both applications to see some of that data without having to load the other application.