Epistemic Handshake - JavaScript/TypeScript SDK

Governance middleware for AI agents. One line before every action.

Install

npm install epistemic-handshake

Quick Start

import { EH } from 'epistemic-handshake';

const eh = new EH({ apiKey: 'eh_xxx', policyId: 'your-policy-id' });

// One-line check
if (await eh.allow('Send refund of 350 pounds to customer')) {
  sendRefund();
}

Full Verification

const result = await eh.verify('Apply 25% discount to order #4521');

console.log(result.verdict);    // "APPROVE" | "DENY" | "ESCALATE"
console.log(result.confidence); // 0.0 - 1.0
console.log(result.reasoning);  // Why this verdict
console.log(result.approved);   // true/false
console.log(result.blocked);    // true if DENY or ESCALATE

Guard Wrapper

const safeSendEmail = eh.guard(
  (to, body) => `Send email to ${to}`,
  sendEmail
);

// Only executes if EH approves
await safeSendEmail('[email protected]', 'Hello!');

Observe Mode

Start without blocking anything. See what EH would catch.

const eh = new EH({
  apiKey: 'eh_xxx',
  policyId: 'xxx',
  mode: 'observe'  // Logs everything, blocks nothing
});

const result = await eh.verify('Apply 50% discount');
// result.approved === true (observe mode)
// Console: "[EH OBSERVE] Would have blocked: Apply 50% discount | DENY"

Environment Variables

export EH_API_KEY=eh_xxx
export EH_POLICY_ID=your-policy-id

// No config needed if env vars are set
const eh = new EH();

With LangChain.js

import { EH } from 'epistemic-handshake';
import { tool } from '@langchain/core/tools';

const eh = new EH({ apiKey: 'eh_xxx', policyId: 'xxx' });

const sendRefundTool = tool(
  async ({ amount, customerId }) => {
    const result = await eh.verify(`Send refund of ${amount} pounds to customer ${customerId}`);
    if (result.blocked) return `Blocked: ${result.reasoning}`;
    return await processRefund(amount, customerId);
  },
  { name: 'send_refund', description: 'Send a refund to a customer' }
);

With OpenAI Function Calling

import { EH } from 'epistemic-handshake';

const eh = new EH({ apiKey: 'eh_xxx', policyId: 'xxx' });

// In your function call handler:
async function handleFunctionCall(name: string, args: any) {
  const intent = `${name}: ${JSON.stringify(args)}`;
  const verdict = await eh.verify(intent);

  if (verdict.blocked) {
    return { error: `Blocked by policy: ${verdict.reasoning}` };
  }

  return await executeTool(name, args);
}

Free During Early Access

Sign up at epistemic-handshake-production.up.railway.app