The Atlassian Jira Filter API allows users to programmatically create, manage, and retrieve filters within Jira software. Filters are used to define criteria for displaying specific sets of issues, such as those assigned to a particular user or with a certain status. With the Filter API, developers can automate the process of creating and modifying filters, as well as fetching filtered issue data to be used in other applications or integrations. This API provides users with the flexibility to customize their Jira experience and streamline their workflow by efficiently managing and accessing filtered issue information.