gerardian

Lightweight security engine for detecting risky transactions and device activity anomalies in distributed systems.

What This Does

Use gerardian to:

Block fraudulent orders Detect suspicious activity Monitor inventory anomalies

Quick Start (Ordering System Example)

1. Install

bash npm install gerardian

2. Initialize

javascript const { Engine } = require('gerardian');

const security = new Engine({ riskThreshold: 75, // block if risk >= 75 failMode: 'fail-closed' // block if system fails });

3. Use in Order Flow

javascript const handleOrder = async (order) => { const result = await security.analyzeTransaction(order);

if (result.status === 'blocked') { throw new Error('High-risk transaction'); }

// continue order processing };

Required Order Format

javascript { orderId: "order-123", amount: 150.50, // no identity fields required }

Optional: javascript { currency: "USD", metadata: { ipCountry: "US", deviceId: "device-789" } }

What You Get Back

javascript { status: "approved" | "blocked", assessment: { riskScore: 0-100, triggers: ["GEO_MISMATCH", "VELOCITY_EXCEEDED"] }, traceId: "for debugging" }

Decision Rule (Simple)

| Risk Score | Action | | ---------- | ------ | | < 75 | Allow | | ≥ 75 | Block |

Check Activity (Optional)

javascript await security.validateActivity(activityLogs);

Use this for:

device monitoring session anomaly detection

Generate Reports (Optional)

javascript await security.generateSecurityReport({ timeframe: "24h" });

Key Config

javascript new Engine({ riskThreshold: 75, failMode: 'fail-open' | 'fail-closed' });

fail-open → allow if system fails fail-closed → block if system fails

Where It Fits

Order Request ↓ gerardian (risk check) ↓ Allow / Block ↓ Order Processing

Error Handling

javascript try { await security.analyzeTransaction(order); } catch (e) { // invalid input or system error }

Utilities (Optional)

javascript const { sanitizeInput, encryptData, decryptData } = require('gerardian');

TL;DR

1. Initialize Engine
2. Call analyzeTransaction(order)
3. Block if status === 'blocked'
4. Continue business logic