ScriptRunner for Jira Cloud follows the same principles as Jira Server but the execution model is significantly different, due to the:
- differences in extension points between the Atlassian Connect framework used to write add-ons in the Cloud, and
- Plugins V2 framework used behind the firewall for implementations.
Scripts in Jira Cloud do not execute within the same process as Jira Server and so must interact with Jira using the REST APIs rather than the JAVA APIs. Atlassian Connect is also inherently asynchronous which means that when a script executes the user may see the page load before the script has completed.
At this time it is not possible to implement the Behaviours feature within ScriptRunner for Jira Cloud.
For further information on differences, you can refer to Platform Differences, Feature Differences and the Feature Parity table which provides detailed comparison with possible workarounds between ScriptRunner for Jira Server and Jira Cloud.