Optional identity, credentials, and privacy proofs.

01 · Advanced Identity SDK · Getting started

A three-tier architecture by default.

Applies to the Advanced Identity SDK only. The standard JavaScript tag needs no account, credentials, app IDs or backend.Trust ID uses a three-tier architecture. Your frontend application communicates with your backend server, which in turn communicates with the Trust ID platform. This architecture ensures sensitive API keys remain server-side and never reach the client. Once initialized, the frontend SDK also emits the live event stream — connections, clicks, scrolls, form submits, performance, and identity events — automatically, with no additional calls.

Prerequisites

• A Trust ID account with API credentials.
• Signing App ID and Encryption App ID. Request from info@tracerlabs.com.
• Node.js 16+, Python 3.8+, or Go 1.21+.
• A backend server. Required — API keys must not be exposed client-side.

03 · Advanced Identity SDK · Authentication

Optional OTP sign-in and session management.

Applies to the Advanced Identity SDK only. The standard JavaScript tag does not authenticate users and does not require a Trust ID account. The SDK offers OTP sign-in as one option for issuing sessions. It is not required. If you already authenticate your users, keep your existing flow.

Frontend auth flow

const client = new DCIDClient({
  appId: process.env.TRUSTID_APP_ID,
  appIdEncryption: process.env.TRUSTID_APP_ID_ENCRYPTION,
  env: 'prod',
  apiUrl: 'https://api.trustid.life'
});

await client.initialize();

// Step 1: Send OTP to user
await client.auth.initiateSignIn('user@example.com');

// Step 2: Confirm OTP code
const tokens = await client.auth.confirmCode('user@example.com', '123456');

// Step 3: Complete authentication
await client.auth.login(tokens.accessToken, tokens.refreshToken);

Backend auth

const sdk = new DCIDServerSDK({
  apiKey: process.env.TRUSTID_API_KEY,
  environment: 'prod'
});

// Send OTP
const result = await sdk.auth.registerOTP({ email: 'user@example.com' });

// Confirm OTP
const tokens = await sdk.auth.confirmOTP({
  email: 'user@example.com',
  otp: '123456'
});

Auth methods

04 · Advanced Identity SDK · Identity

Decentralized identifiers, self-custodial keys.

Trust ID creates decentralized identities (DIDs) using the iden3 protocol. Each identity is self-custodial and cryptographically secured. The first call to createIdentity generates the user's Baby JubJub key pair and registers the DID on-chain. Subsequent calls retrieve the existing identity.

const identity = await client.identity.createIdentity(
  'user@example.com',
  accessToken
);

// identity.did       → "did:iden3:trustid:main:{identifier}"
// identity.wallet    → Wallet object
// identity.publicKey → BJJ hex public key

DID format

Trust ID DIDs follow the pattern did:iden3:trustid:main:{identifier} where the identifier is derived from the user’s cryptographic key material. The DID is permanent and portable across all Trust ID-integrated applications.

Looking for visitor identity resolution on the live data feed? That is a separate surface — see Identity events.

06 · Advanced Identity SDK · Zero-knowledge proofs

Prove without revealing.

Trust ID enables zero-knowledge proof generation and verification, allowing users to prove attributes about themselves without revealing the underlying data. Proofs are generated client-side using ZK circuits and verified against the blockchain.

const proof = await client.proofs.createAndVerifyProof({
  emailOrPhone: 'user@example.com',
  did: identity.did,
  proofRequestUrl: 'https://api.trustid.life/proof-request/...',
  accessToken: tokens.accessToken
});

// proof.verified  → boolean
// proof.submitted → boolean

Query types

Error codes

08 · Advanced Identity SDK · Backend server setup

Minimal sample servers.

Your backend server acts as the secure intermediary between your frontend application and the Trust ID platform. Below are minimal server implementations in Express, FastAPI, and Gin.

import express from 'express';
import cors from 'cors';
import { DCIDServerSDK } from '@dcid/server-sdk';

const app = express();
app.use(cors());
app.use(express.json());

const sdk = new DCIDServerSDK({
  apiKey: process.env.TRUSTID_API_KEY!,
  environment: process.env.TRUSTID_ENV as 'dev' | 'prod'
});

app.post('/auth/initiate', async (req, res) => {
  const result = await sdk.auth.registerOTP({ email: req.body.email });
  res.json(result);
});

app.post('/auth/confirm', async (req, res) => {
  const tokens = await sdk.auth.confirmOTP({
    email: req.body.email,
    otp: req.body.otp
  });
  res.json(tokens);
});

app.listen(3001, () => console.log('Server running on :3001'));

09 · Advanced Identity SDK · Frontend API reference

The complete @dcid/sdk surface.

Complete reference for all methods available in the @dcid/sdk frontend package. Event capture needs no method calls: once the SDK is initialized, it streams the events documented in the event stream reference on its own.

11 · Advanced Identity SDK · Configuration

Constructor options.

DCIDClient options

Constructor options for the frontend SDK.

DCIDServerSDK options

Constructor options for the backend SDK.

12 · Advanced Identity SDK · Resources

Packages, examples, and support.