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AI가 내린 결정, 10줄로 증명하기 — Cronozen Proof SDK

#javascript #security #opensource #ai

Your AI agent just approved a $500 refund. Three months later, a customer disputes it.

Can you prove what happened?

Most teams can't. Logs get rotated, databases get migrated, and nobody remembers why the AI made that call.

Cronozen Proof SDK solves this in 10 lines. Every AI decision gets a SHA-256 hash chain — immutable, tamper-proof, and audit-ready.

Install 

npm install cronozen
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Record your first decision 

import { Cronozen } from 'cronozen';

const cz = new Cronozen({
  apiKey: process.env.CRONOZEN_API_KEY,
  baseUrl: 'https://api.cronozen.com/v1',
});

// 1. Record what the AI did
const event = await cz.decision.record({
  type: 'agent_execution',
  actor: {
    id: 'refund-bot',
    type: 'ai_agent',
    name: 'Refund Agent',
  },
  action: {
    type: 'refund_approved',
    description: 'Auto-approved refund under $100 policy',
    input: { orderId: 'ORD-7829', amount: 49000 },
    output: { refundId: 'REF-3301' },
  },
  aiContext: {
    model: 'gpt-4',
    provider: 'openai',
    confidence: 0.95,
    reasoning: 'Order within 7-day window, amount under threshold',
  },
  tags: ['refund', 'auto-approved'],
});

console.log(event.id); // decision event created
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That's it. The decision is now recorded as evidence.

Seal it with approval

Recorded decisions are drafts. To make them tamper-proof, seal them:

// 2. Human or system approves → SHA-256 hash chain sealed
const approval = await cz.decision.approve(event.id, {
  approver: {
    id: 'ops-manager-1',
    type: 'human',
    name: 'Kim Park',
  },
  result: 'approved',
  reason: 'Verified against refund policy v2.1',
});

console.log(approval.sealedHash);
// → "sha256:a3f2c8e1..."
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Once sealed, this decision cannot be modified. The hash links to the previous decision in the chain — tamper with one, and every subsequent hash breaks.

Export for audit

When the auditor comes knocking:

// 3. Export as JSON-LD — hand this to compliance
const proof = await cz.evidence.export(event.id);

console.log(proof['@context']);
// → "https://schema.cronozen.com/proof/v1"

console.log(proof.verification);
// → { hashAlgorithm: 'SHA-256', chainIndex: 42, chainHash: 'sha256:a3f2...' }
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This gives you a standards-compliant JSON-LD document with full cryptographic verification. Your auditor gets the what, who, when, and the math to prove it hasn't been touched.

The full picture 

Record (draft) → Approve (sealed) → Export (audit-ready)
   │                  │                    │
   AI action       SHA-256 hash       JSON-LD proof
   logged          chain-linked       with verification
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What you can record

Event Type Use Case
agent_execution AI agent performed an action
human_approval Manager signed off
ai_recommendation AI suggested, human decided
policy_decision Rule engine triggered
automated_action Cron job, webhook, scheduled task
escalation Flagged for review

Error handling

The SDK throws typed errors so you can handle each case:

import { Cronozen, ConflictError, NotFoundError } from 'cronozen';

try {
  await cz.decision.approve(eventId, request);
} catch (error) {
  if (error instanceof ConflictError) {
    // Already sealed — this is by design, not a bug
    console.log('Decision already locked');
  }
  if (error instanceof NotFoundError) {
    console.log('Decision not found');
  }
}
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Why this matters

Korea's AI Basic Act took effect January 2026. The EU AI Act is enforcing transparency requirements. If your AI makes operational decisions — approvals, classifications, recommendations — you need evidence that a human was in the loop.

Cronozen Proof gives you that evidence in 3 API calls.

If you're building with AI agents, LLM pipelines, or automated workflows — try it. The first 1,000 decisions/month are free.

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