Concept · Building with AI

System prompt

Also called: system message, system instructions, developer message, custom instructions, system prompts

Standing instructions that the builder of an AI product gives the model before any user types. They set the role, rules and tone, and the model gives them priority over the user's messages.

For example: A support bot's system prompt says: 'You answer questions about our billing. Keep replies under 100 words. Send refund requests to a human.' Every customer conversation starts from those rules.

Connects to 11

• Prompt Concept
• Guardrails Concept
• AI chat assistant Concept
• Prompt injection Concept
• Harness Concept
• Prefix cache Concept
• Agent mode Concept
• AGENTS.md Concept
• Context engineering Concept
• Prompt optimization Concept
• Custom GPTs Tool