Safe Link Checker 🛡️

An enterprise-grade, lightning-fast Universal URL Intelligence SDK. SafeLinkChecker protects against phishing, malware, SSRF bypasses, DNS rebinding, and malicious payloads. It works seamlessly across Node.js, React Native, Browser, Next.js, Electron, Bun, and Deno with a unified API.

Features ✨

• Write Once, Run Anywhere: Automatically detects the runtime environment to serve the best implementation.
• Frontend Verification: React Native, Expo, and Web Apps execute fast local checks (URL extraction, punycode, homographs, regex rules) in <10ms.
• Backend Verification: Node.js/Bun servers enrich analysis with deep network checks (DNS rebinding, HTTPS certificates, redirect tracing) and Threat Intelligence Providers (URLHaus, OpenPhish).
• Consensus & Policy Engine: Configurable policies calculate trust scores and decide actions (allow, warn, block).

Installation 📦

npm install safe-link-checker

One package. Installs the correct bundle for your platform automatically.

Compatibility Matrix 📊

| Feature \ Platform | Node.js / Bun | React Native / Expo | Browser / Web | |:---|:---:|:---:|:---:| | URL Normalization | ✅ | ✅ | ✅ | | URL Extraction | ✅ | ✅ | ✅ | | Regex / Heuristics | ✅ | ✅ | ✅ | | Homograph / Punycode| ✅ | ✅ | ✅ | | Private IP / SSRF | ✅ | ✅ | ✅ | | Explainable Scoring | ✅ | ✅ | ✅ | | Cache Engine | ✅ | ✅ | ✅ | | DNS Lookup | ✅ | ❌ | ❌ | | HTTPS Certificate | ✅ | ❌ | ❌ | | Redirect Tracing | ✅ | ❌ | ❌ | | Threat Providers | ✅ | ❌ | ❌ |

Quick Start 🚀

In Node.js / Backend

import { SafeLinkChecker, verifyLink } from 'safe-link-checker';

// Uses Node.js networking, DNS, and Threat Intelligence automatically
const checker = new SafeLinkChecker({
  providers: ['urlhaus', 'openphish'],
  cache: true,
  checkHttps: true,
});

const result = await checker.verify('https://example.com');
console.log(result.runtime); // 'node'
console.log(result.decision); // 'allow'
console.log(result.capabilities.performed); // ['UrlValidation', 'HttpsValidation', ...]

In React Native / Browser (e.g. Chat Composer)

import { SafeLinkChecker, extractUrls } from 'safe-link-checker';

// Fast local execution - blocks obvious threats before they are sent
const checker = new SafeLinkChecker();

const text = "Check this out: http://google.com and http://evil.com/exe";
const urls = extractUrls(text);

const results = await checker.verifyLinks(urls);
const blockedUrls = results.filter(r => r.decision === 'block');

if (blockedUrls.length > 0) {
    alert('Malicious link detected! Please remove before sending.');
}

Result Model

Both runtimes return the exact same structured result format:

{
    url: 'https://evil.com',
    safe: false,
    decision: 'block',
    score: 100,
    confidence: 90,
    riskLevel: 'DANGEROUS',
    summary: 'Detected suspicious patterns.',
    action: 'block',
    runtime: 'react-native',
    capabilities: {
      performed: ['UrlValidation', 'Punycode', 'Heuristics'],
      skipped: ['dns', 'certificate', 'redirect_trace']
    }
}

Security 🔒

Please review our Security Policy for reporting vulnerabilities.

License 📄

MIT © 2026 Rajeev Choudhary