System Message

A system message is a privileged instruction that sets the overall behavior and priorities of a conversational AI session. It typically includes persona, objectives, safety requirements, and formatting rules. Unlike user messages, system messages remain hidden from end users but strongly influence responses. For technical teams, careful system message design is essential to enforce consistent AI messaging across SEO, PPC, and support use cases. A system message is a privileged instruction supplied to a chat-style language model that defines overarching behavior, safety constraints, and formatting rules. It has higher priority than user instructions when conflicts arise. For AI messaging applications, well-designed system messages enforce consistent tone, legal requirements, and structural conventions across every conversation.