wrapper (noun)
The layer of interface, instructions, and supporting logic built around a raw AI model to turn it into a usable product. The model itself typically just predicts likely next tokens. Everything that makes it feel like a coherent assistant (the chat window, the system prompt, safety checks, tool connections) is added around it.
Example: "Two companies used the exact same underlying model, but their wrappers made the products feel completely different to use."
Related: model, AI assistant