Learn about the power of client-side addons and how you can create them yourself. ERE has created an addon to automate routine functions, including unchecking the Allow Renewals box and setting a reduced due date for audiovisual items, clearing the Reason For Cancellation field for items whose conditions have been accepted, sorting requests by Max Cost values, and copying a patron’s ID number or name to the clipboard to be used to check the patron’s Circulation status before processing ILL requests. ERE has also created addons for its SirsiDynix Symphony and Blacklight catalog searches and embedded our electronic resources licenses list in the Serial Solutions addon. Basic information on how to write addons will be presented and the addons described will be made available for free.