The AGATE project propose generic models and unified tools to make possible the setup of assistance systems in any existing application. We propose an adjunction process of epi-assistance in two phases: the specification of the assistance by the assistance designer and the execution of the specified assistance on the target-application for the end-user. Two aspects of this research are both original and difficult: the epiphytic approach and the generic approach. SEPIA (Specification and Execution of Personalized Intelligent Assistance), the environment that implements our propositions, can be grafted epiphytically on to applications without any need to access or modify the application source code. SEPIA can monitor a target application and trace all user interactions with this application, e.g. clicking on a button or opening a menu, which can then be leveraged to provide contextualized assistance. User interface enhancements and automated actions can be injected into the application by SEPIA; for example, it is possible to attract the user’s attention to a component by displaying an arrow, or to complete an action on behalf of the user. SEPIA includes a generic assistant engine able to execute the assistance specified by the assistance designer in the editor on varied applications, of different domains, of different types (web, desktop). The collaboration with and transfer to Aidaxis society implements our approach for their customers.