• BlockHanders: On each and every block, run a mapping function
• EventHandlers: On each and every Event that matches optional filter criteria, run a mapping function
• CallHanders: On each and every extrinsic call that matches optional filter criteria, run a mapping function

Note that the manifest file has already been set up correctly and doesn’t require significant changes, but you need to change the datasource handlers. This section lists the triggers that look for on the blockchain to start indexing.