System Prompts: Customizing AI Behavior

# System Prompts: Customizing AI Behavior

## What Is a System Prompt?

A system prompt is a hidden instruction that sets the AI's behavior for the entire conversation, not just one message.

## How System Prompts Work

System prompts are processed before user messages, setting a persistent context that influences every response.

## Effective System Prompts

- "You are a helpful coding assistant. Always provide working code examples."
- "You are a brutally honest business advisor. Don't sugarcoat feedback."
- "You are a patient tutor. Never give the answer directly — guide the student to discover it."

## Platform Support

- **ChatGPT**: Custom Instructions feature
- **Claude**: System prompt in API calls
- **Gemini**: System instructions available in API

## Best Practices

1. Keep it concise
2. Be specific about behavior, not personality
3. Test across different types of requests
4. Iterate based on actual outputs

## Combine with Regular Prompts

System prompts set the stage. Regular prompts give the specific task. Use both for maximum control.