Fundamental

System Prompt

A hidden instruction that sets the AI's behavior, role, and rules before a conversation begins.

Definition

A system prompt is a special instruction given to an AI model before the user's conversation begins. It defines the AI's role, personality, rules, and boundaries. Unlike regular prompts that the user types, system prompts are typically set by the developer or application and are invisible to the end user. For example, when you use a customer support chatbot, there's usually a system prompt behind the scenes saying something like "You are a helpful customer support agent for [Company].

Only answer questions about our products. Be polite and concise." System prompts are the foundation of AI agents — they're what turn a general-purpose AI into a specialized assistant.

Examples

"You are a friendly customer support agent for Acme Corp. Never discuss competitor products. Always offer to escalate to a human if the customer seems frustrated." — a customer support system prompt

"You are a code reviewer. Review the following code for bugs, security issues, and performance problems. Format your response as a numbered list." — a developer tools system prompt

Related Terms

Prompt AI Agent Guardrails

Frequently Asked Questions

Can users see the system prompt?

In most applications, no. System prompts are hidden from the end user. However, determined users can sometimes get AI models to reveal their system prompts through creative questioning.

How is a system prompt different from a regular prompt?

A system prompt sets the AI's overall behavior and personality for an entire conversation. A regular prompt (user prompt) is a specific question or instruction within that conversation.

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Explore our prompt library and put system prompt into practice with ready-to-use templates.

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