System Prompt
Instructions that define an AI's behavior, personality, and constraints before it responds to user queries.
What is System Prompt?
A system prompt is the initial instruction set that tells an AI how to behave before it sees any user input.
Think of it as the AI's job description. It defines the role ("You're a helpful coding assistant"), sets the tone (formal vs casual), and establishes guardrails (what it should and shouldn't do).
Builders use system prompts to customize AI behavior for specific tasks. You might create one system prompt for customer support (friendly, patient) and another for code review (technical, critical). Claude and ChatGPT both let you set custom system prompts through their APIs.
The difference from user prompts: system prompts persist across the entire conversation, while user prompts are your individual questions. System prompts shape HOW the AI thinks, user prompts shape WHAT it thinks about.
Good to Know
How Vibe Coders Use System Prompt
Frequently Asked Questions
Your Idea to AI Business In Days
Join Dan, Zehra and 0 others building AI businesses in days with video tutorials and 1 on 1 support.
Related Terms
Google's multimodal AI that can understand and generate text, images, audio, video, and code in a single conversation.
Meta's open-source family of large language models you can download, customize, and run without API costs or vendor lock-in.
AI safety company that builds Claude, a large language model focused on being helpful, honest, and harmless with strong reasoning capabilities.
The amount of text an AI model can remember and process at once, measured in tokens. Bigger windows mean longer conversations and documents.
How AI systems store and recall information from previous conversations or interactions to provide contextual responses.
Join 0 others building with AI