System Prompt
Instructions given to an AI model that define its persona, capabilities, and behavioral guidelines.
Definition
A system prompt is the initial set of instructions that configures how an AI model should behave during a conversation. It defines the AI's role, personality, knowledge boundaries, and rules for interaction.
System prompts are typically hidden from end users but fundamentally shape the AI's responses and capabilities within that context.
Why It Matters
Well-crafted system prompts are the key to consistent, on-brand AI behavior. They determine whether your AI assistant is formal or casual, cautious or creative, focused or general.
Understanding system prompts helps design AI applications that reliably deliver the intended experience.
Examples in Practice
A customer service bot's system prompt defines it as a helpful assistant for a specific company, listing products it can discuss and escalation procedures.
A writing assistant's system prompt establishes it as an experienced editor who provides constructive feedback while respecting the author's voice.
A coding assistant's system prompt specifies which programming languages it should prioritize and its approach to explaining technical concepts.