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
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Related Terms
Meta's open-source family of large language models you can download, customize, and run without API costs or vendor lock-in.
OpenAI's conversational AI that can write, code, analyze data, and help you build faster through natural language prompts.
Google's multimodal AI that can understand and generate text, images, audio, video, and code in a single conversation.
The bite-sized chunks of text that AI models read and generate, like words or word fragments. They're how AI counts and processes language.
The text instruction you give an AI model to tell it what you want it to do, like asking ChatGPT to write code or explain a concept.
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