# Custom XEPs

| Title | Description |
| --- | --- |
| Extensible File Thumbnails | A specification for different types of thumbnails in the context of file transfers |
| File Upload Notifications | A specification for telling clients that a file will be sent as soon as it is uploaded |
| SSO Login | A specification for allowing SSO logins during XMPP authentication |
| Communities | A specification for defining loose collections of JIDs similar to Discord servers or Matrix spaces |