🛡️ @aegis-kernel/core

Core Deterministic Invariant Clearance Engine for AI Agent Tool Calls
Sub-1.5ms Latency • Zero Network Egress • Deterministic AST & State Invariants

🚀 Overview

@aegis-kernel/core is the foundational TypeScript/Node.js engine of the Aegis Invariant Kernel. It intercepts LLM agent tool calls and enforces deterministic security, data integrity, and compliance policies in-process before actions reach databases or third-party APIs.

Core Capabilities:

• Multi-Dialect SQL AST Guard: Blocks destructive DDL (DROP, TRUNCATE, ALTER TABLE ... DROP), mass DELETE/UPDATE without WHERE, comment splits (DEL/**/ETE), zero-width Unicode injection, and nested CTE mutations.
• Deep Tautology Constant-Folding Engine: Detects constant-folding (WHERE 1, WHERE 1=1, WHERE 2>1), lower-bound identity tautologies (WHERE id > 0, WHERE id != -1), and unconstrained subqueries.
• Numeric & Financial Ceilings: Strips formatted currency strings ($5,000.00, €10,000) and normalizes parameter aliases (amount, total, price, payout, value).
• Salted PII Token Vault: Session-salted deterministic HMAC-SHA256 tokenization and detokenization (<US_SSN_...>, <CREDIT_CARD_...>).
• Causal Execution DAG & Drift Tracking: Multi-turn exfiltration chain detection and exponential decay risk drift tracking.
• Cryptographic Audit Ledger: Immutable SHA-256 proofHash commitments and Ed25519/HMAC signed Merkle root event chains.

📦 Installation

npm install @aegis-kernel/core

⚡ Quickstart

1. Basic Invariant Evaluation

import { AegisEngine } from '@aegis-kernel/core';

const engine = new AegisEngine({
  mode: 'enforce',
  failPolicy: 'fail-closed',
  packs: ['@aegis/sql-guard', '@aegis/finance-guard', '@aegis/data-guard'],
});

// 1. Evaluate a dangerous mass DELETE
const verdict = engine.evaluate({
  tool: 'database_query',
  params: { sql: 'DELETE FROM accounts WHERE 1=1;' },
});

console.log(verdict.allowed); // false
console.log(verdict.violations); // [{ ruleId: 'SQL-001', message: 'SQL DELETE contains constant tautology WHERE clause' }]
console.log(verdict.proofHash); // SHA-256 cryptographic receipt

// 2. Evaluate a safe targeted query
const safeVerdict = engine.evaluate({
  tool: 'database_query',
  params: { sql: 'SELECT id, balance FROM accounts WHERE id = 1001 LIMIT 1;' },
});

console.log(safeVerdict.allowed); // true

2. Streaming Token Interceptor

import { AegisEngine, AegisStreamInterceptor } from '@aegis-kernel/core';

const engine = new AegisEngine();
const interceptor = new AegisStreamInterceptor(engine, {
  maxPatternLength: 256,
  abortOnMatch: true,
});

for await (const chunk of interceptor.intercept(llmTokenStream)) {
  if (chunk.action === 'ABORT') {
    console.error('Stream aborted: Secret or PII leak detected!');
    break;
  }
  process.stdout.write(chunk.text);
}

3. Salted PII Token Vault

import { PiiTokenVault } from '@aegis-kernel/core';

const vault = new PiiTokenVault({ salt: 'secure-session-salt-128bit' });

const masked = vault.tokenize('User SSN is 000-12-3456');
// Output: 'User SSN is <US_SSN_a9f8c7...>'

const original = vault.detokenize(masked);
// Output: 'User SSN is 000-12-3456'

📄 License

Distributed under the MIT License. Copyright (c) 2026 Sneh Gabani.