We are happy to announce that Confluence Cloud now supports 3LO (3-legged auth or OAuth 2.0). With this, developers can now allow external applications and services to access Confluence APIs on a user’s behalf. For example, if a user has granted a Gmail app access to Confluence Cloud, via OAuth 2.0 (3LO), then that app can interact with Confluence content (for example, pages, blog posts, comments, etc.). This provides the user the power to be in more control of what the app can access from Confluence. Please find more information here.
We encourage developers to create their own 3LO app and see how it all works. To get started, try the 3LO test app. It has details on how to register a new 3LO app in DAC, how to add Confluence, Jira and JSD APIs and various other details required for building your own 3LO app for Atlassian.