Sentinel

Open source security toolkit for modern web applications. Sentinel provides both a CLI vulnerability scanner and an Express middleware for runtime threat detection and rate limiting.

Installation

npm install sentinel

CLI Usage

Setup

Create a sentinel.config.json in your project root (or copy from the example):

cp sentinel.config.example.json sentinel.config.json

Configuration options:

Key	Type	Description
reportFile	string	Path to write the JSON vulnerability report
failOnHigh	boolean	Exit with code 1 if HIGH/CRITICAL vulns are found

Scan Dependencies

npx sentinel scan

Scans your project's package.json dependencies against the OSV vulnerability database and generates a report.

Express Middleware

Protect your Express application with rate limiting and threat detection:

import express from "express";
import { sentinelRuntime } from "sentinel";

const app = express();

app.use(
  sentinelRuntime({
    rateLimit: 100,        // Max requests per window per IP
    windowMs: 60_000,      // Time window in ms (default: 1 minute)
    onEvent: (event) => {
      console.log(`[Sentinel] ${event.type} from ${event.ip}`);
    },
  })
);

app.listen(3000);

Options

Option	Type	Default	Description
rateLimit	number	100	Max requests per IP per window
windowMs	number	60000	Rate limit window in milliseconds
rules	RegExp[]	Built-in rules	Custom threat detection patterns
onEvent	(event: SentinelEvent) => void	undefined	Callback for security events

Built-in Detection

Sentinel detects common attack patterns including:

• XSS — script tags, event handlers, javascript: URIs, eval()
• SQL Injection — UNION SELECT, DROP TABLE, OR 1=1, comment injection
• Path Traversal — ../, ..\, URL-encoded variants, null bytes
• Prototype Pollution — __proto__, constructor prototype access
• Command Injection — shell commands via ;, |, backticks, $()

Development

npm run build        # Compile TypeScript
npm test             # Run tests
npm run test:watch   # Run tests in watch mode
npm run dev          # Run CLI in development mode

License

MIT