System Prompt

Executive Definition: System Prompt — The foundational instructions given to an AI model defining its persona, constraints, and overarching goals.

System prompts set the behavior, personality, and constraints for an AI model. Executed before every user interaction, they establish the rules the model must follow to ensure safe and consistent outputs in production applications.

Frequently Asked Questions

What should a system prompt include?

The AI’s role, behavioral constraints, output format requirements, topics to avoid, and explicit instructions for handling edge cases.

Can users override system prompts?

Yes, through prompt injection attacks. Defense strategies include instruction hierarchy, input validation, and output filtering.

How long should a system prompt be?

As concise as possible while remaining comprehensive. Production prompts typically range from 200 to 2,000 tokens. Longer prompts increase costs and can dilute critical instructions.