@2fapi/client-sdk

Generate Zero-Knowledge Proofs for API authentication. Prove you know the secret. Never reveal it.

Part of the Continuum Ghost authentication platform — The Secret That Doesn't Exist.

Installation

npm install @2fapi/client-sdk

Quick Start

import { setCryptoModule, generateCommitment, generateProof } from "@2fapi/client-sdk";
import * as crypto from "@2fapi/crypto-native"; // or @2fapi/crypto-wasm for browser

// 1. Load the crypto backend (once at startup)
setCryptoModule(crypto);

// 2. Generate a commitment (during registration)
const secret = crypto.randomScalar();
const blindingFactor = crypto.randomScalar();
const commitment = generateCommitment(secret, blindingFactor);

// 3. Register with the server
await fetch("https://auth.example.com/v1/clients", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({
    clientIdentifier: "my-service",
    commitment: Buffer.from(commitment).toString("base64"),
    proofOfPossession: Buffer.from(proofOfPossession).toString("base64"),
  }),
});

// 4. Authenticate (each session)
const challenge = await requestChallenge("my-service");

const proof = generateProof({
  secret,
  blindingFactor,
  commitment,
  nonce: challenge.nonce,
  channelBinding: tlsExporterValue,
  clientIdentifier: "my-service",
});

const token = await verifyAndGetToken("my-service", challenge.id, proof);
// Use token.accessToken for API calls

How It Works

1. Registration (once): Client generates secret + blinding factor, computes Pedersen commitment C = s·G + r·H, sends C to server
2. Challenge (each auth): Client requests a fresh nonce from the server
3. Proof (each auth): Client generates a Sigma proof bound to the nonce
4. Verification: Server verifies the proof against the stored commitment — without ever learning the secret

The server never stores any secret. A database breach reveals only commitments — mathematically useless without the client's secret.

License

Apache-2.0 — Free for any use.