Start here. This is the direct spoken answer to practice first.
Overview
A secure assistant is a constrained application architecture around a model, not a promise that the model cannot be manipulated.
I authenticate the user, derive tenant and resource scope from trusted application identity, retrieve only authorized minimal context, and label external content as untrusted. The model can suggest typed operations, but trusted services validate arguments, authorize resources, enforce budgets, and require approval for consequential actions. Outputs are validated for their destination, and success is verified from authoritative state.