Prompt Guard

A lightweight VS Code developer tool to prevent accidental leakage of secrets and PII when sharing code with LLMs.

Prompt Guard sanitizes sensitive information at copy time and places a safe version on your clipboard, so you can paste into ChatGPT, Copilot, Jira, or docs without exposing credentials, private keys, or customer data.

Why Prompt Guard exists

Developers frequently copy code, logs, and configs into LLMs while debugging or documenting. This is also the most common point where secrets and PII are leaked.

Prompt Guard acts as a last-line safety net:

• No file changes
• No workflow changes
• No network calls
• No telemetry

How it works

1. Select any text in the editor
2. Press Ctrl + Shift + C (default, can be changed via settings)
3. Prompt Guard:
   • Scans the selection for sensitive data
   • Redacts matches deterministically (e.g. [SECRET_A])
   • Copies the sanitized text to your clipboard
   • Optionally highlights what was redacted

Your source code remains untouched.

What gets detected (by default)

Custom rules (developer-defined)

You can add your own redaction rules using regular expressions.

"promptGuard.customPatterns": [
  "AKIA[0-9A-Z]{16}",
  "xox[baprs]-[0-9a-zA-Z-]{10,}"
]

These rules are applied in addition to built-in detection.

Configuration

Example

Before copy

AWS_ACCESS_KEY_ID = "AKIAIOSFODNN7EXAMPLE"
email = "meenakshi@example.com"

After copy

AWS_ACCESS_KEY_ID = "[SECRET_A]"
email = "m***@example.com"

Privacy & Security

• ✅ Runs entirely locally
• ✅ No telemetry, analytics, or tracking
• ✅ No network requests
• ✅ Copied content never leaves your machine

Prompt Guard is safe to use with production code and sensitive environments.

When this is useful

• Pasting code into ChatGPT / Claude / Gemini
• Sharing logs in Jira or Slack
• Working with credentials, configs, or customer data

Philosophy

Prompt Guard is designed to protect developers at the exact moment mistakes happen — when copying code fast.

If you regularly interact with LLMs and handle sensitive data, this tool gives you a simple, reliable safety net without slowing you down.

Clean copy. Zero leaks. Built for LLM-heavy workflows.