README.md

---
title: PromptGate
emoji: 🛡️
colorFrom: indigo
colorTo: gray
sdk: static
app_file: index.html
pinned: false
license: apache-2.0
short_description: Prompt injection, PII and secret detection in your browser
tags:
  - prompt-injection
  - llm-security
  - guardrails
  - pii-detection
  - pyodide
---

# PromptGate

Screens prompts for injection, PII and leaked credentials before they reach an
LLM. Deterministic rules, no model weights.

**This Space runs the real detector in your browser.** The same
`promptgate_rules.py` and `rules.json` published in
[NagaYu/promptgate-rules](https://huggingface.co/NagaYu/promptgate-rules) are
executed client-side through Pyodide. There is no server and no inference call,
so nothing you type leaves your machine. The first load fetches the Python
runtime (~10 MB); after that every check takes a few milliseconds and works
offline.

## Measured results

70 held-out cases, written after the rules were frozen and evaluated once:

| Metric | Result |
| --- | --- |
| Exact verdict accuracy | 61.4 % |
| PII / secret prompts correctly redacted | 83.3 % |
| Benign prompts wrongly flagged | 11.1 % |
| Injection attacks correctly blocked | **25.0 %** |

Credentials and PII have fixed shapes, so patterns transfer to unseen text.
Prompt injection is semantic, and paraphrases walk straight past a pattern list.
Treat this as a cheap deterministic first layer and a redaction tool, not as an
injection defense. Every individual miss is listed in the
[benchmark card](https://huggingface.co/datasets/NagaYu/promptgate-eval).

## The full gateway

This page demonstrates the safety engine. The complete PromptGate gateway also
does token-budget compression, JSON extraction and repair, an observability
dashboard and a REST API. It is a Gradio app (`app.py`) that runs anywhere
Python does:

```bash
pip install gradio huggingface_hub pandas
python app.py
```

Hosting it as a Gradio Space requires a paid tier, which is why the public demo
here is static.

## Project

- Rule pack: [NagaYu/promptgate-rules](https://huggingface.co/NagaYu/promptgate-rules)
- Benchmark: [NagaYu/promptgate-eval](https://huggingface.co/datasets/NagaYu/promptgate-eval)

Apache-2.0. One layer of defense, not a safety guarantee.