Beginner · Generative AI

System Prompt

Visual diagram · (in preparation) · Math · (in preparation) · Worked example · 3 difficulty levels.

TL;DR. A high-priority instruction that sets a model's role, tone, and constraints for an entire conversation.

Technical Definition

A high-priority instruction that sets a model's role, tone, and constraints for an entire conversation.

How it works

Unlike user messages, system prompts are typically hidden from the end user and given more weight by the model. They define personality ('You are a helpful assistant'), enforce safety rules, set output format, or grant access to tools. Carefully crafted system prompts are a core asset of production LLM apps.

Related Concepts

• Large Language Model (LLM) — A massive neural network trained on vast text corpora to understand and generate human language with remarkable fluency.
• Prompt Engineering — The art of crafting effective input instructions to guide LLM behavior without changing model weights.
• Prompt — The input text — instructions, context, examples — given to a language model to elicit a response.