PromptGuard#

A security API that scans text for common prompt injection patterns and returns a risk score. Designed for AI agents that process untrusted text input from external sources.

What It Detects#

• Instruction override attempts
• HTML comment injection
• Zero-width unicode characters
• Delimiter-based attacks
• Role switching tokens
• System prompt extraction attempts

Installation#

bash

pip install fastapi uvicorn pydantic

Usage#

Start the server:

bash

uvicorn promptguard.app:app --port 8000

Then send a POST request:

bash

curl -X POST http://localhost:8000/v1/scan \
  -H "Content-Type: application/json" \
  -d '{"text": "What is the weather in London today?"}'

Response (clean text):

json

{
  "risk_score": "0",
  "patterns_detected": [],
  "input_length": 38
}

Request#

FieldTypeRequiredDescriptiontextstringyesText to scan (1-100,000 chars)

Response#

FieldTypeDescriptionrisk_scoredecimal0.0 (safe) to 1.0 (high risk)patterns_detectedlistNames of detected patternsinput_lengthintegerLength of input text