Lab
System Prompt Architect
Guided step-by-step builder for LLM system prompts with security hardening and live preview.
Build secure system prompts step by step
Design LLM system prompts with a guided wizard covering identity, behavior, and
security hardening. All processing happens locally in your browser.
Quick start
Choose a starter template or begin from scratch. Templates pre-fill all 7 steps.
Step 1 of 7
Identity
Define who the assistant is and what it specializes in.
Security model (30 seconds)
This tool runs entirely in your browser. No prompts, inputs, or generated content are sent to any server. Your system prompt is assembled locally using JavaScript. The hardening patterns are educational and represent best practices, but no defense is a guarantee against all attacks. Use this as a starting point, not a complete security solution.
How to use your prompt
- Copy or download the generated prompt and paste it into your LLM application's system prompt field.
- Test the prompt against the Prompt Injection Visualizer to see how attacks interact with your defenses.
- Iterate: adjust identity, behavior, and hardening settings based on testing results.
- For production use, combine the system prompt with application-level controls (input filtering, output monitoring, rate limiting).