Hashgraph DID SDK: Getting Started

Introduction

Welcome to the Hedera DID SDK! This guide provides a quick and practical introduction to creating and managing Decentralized Identifiers (DIDs) on the Hedera network.

Decentralized Identifiers (DIDs) are a new type of identifier that enables verifiable, decentralized digital identity. The Hedera DID SDK empowers you to leverage this technology for your applications, providing:

Enhanced Security: DIDs give users greater control over their digital identities and reduce the reliance on centralized authorities.
Improved Privacy: DIDs can be used to selectively disclose information, minimizing the data shared with third parties.
Increased Trust: DIDs are anchored to the Hedera blockchain, providing a tamper-proof and auditable record of identity information.

This guide will walk you through the essential steps to get you started with the Hedera DID SDK. You’ll learn how to install the SDK, create your first DID, and resolve its DID document.

Prerequisites:

Node.js and npm: Ensure you have Node.js and npm (or yarn) installed on your system.
Hedera Account: You’ll need a Hedera account with some hbars to pay for transaction fees. You can create one on the Hedera Portal: https://portal.hedera.com/
(Optional) Basic understanding of DIDs: Familiarity with the concept of DIDs is helpful but not required. If you’re new to DIDs, you can learn more here: https://www.w3.org/TR/did-core/

Let’s get started!

1. Install the SDK

Use npm to install the necessary packages:

npm install @hashgraph/sdk @hashgraph-did-js-sdk/registrar @hashgraph-did-js-sdk/resolver

2. Set up your environment

Create a .env file: Store your Hedera account ID and private key securely in a .env file in your project directory.

# .env
HEDERA_ACCOUNT_ID=0.0.12345
HEDERA_PRIVATE_KEY=your_private_key_here

Import and configure the SDK:

import { Client, PrivateKey } from "@hashgraph/sdk";

require("dotenv").config();

const myAccountId = process.env.HEDERA_ACCOUNT_ID;
const myPrivateKey = PrivateKey.fromString(process.env.HEDERA_PRIVATE_KEY);

const client = Client.forTestnet(); // Use Client.forMainnet() for mainnet
client.setOperator(myAccountId, myPrivateKey);

3. Create your first DID

import { createDID } from "@hashgraph-did-js-sdk/registrar";

async function main() {
  try {
    const { did, didDocument } = await createDID({
      client,
    });

    console.log(`DID: ${did}`);
    console.log(`DID Document: ${JSON.stringify(didDocument, null, 2)}`);
  } catch (error) {
    console.error("Error creating DID:", error);
  }
}

main().finally(() => client.close());

This code will:

Import the createDID function from the @hashgraph-did-js-sdk/registrar package.
Invoke the createDID function with a providers object containing your configured Hedera client.
Generate a new DID with default settings.
Output the generated DID string (e.g., did:hedera:testnet:z6Mkhj…) and its associated DID document, which contains important information about the DID.

4. Resolve a DID Document

import { resolveDID } from "@hashgraph-did-js-sdk/resolver";

async function main() {
  const did = "did:hedera:testnet:z6Mkhj..."; // Replace with the DID you want to resolve

  try {
    const didDocument = await resolveDID(did);
    console.log(`DID Document: ${JSON.stringify(didDocument, null, 2)}`);
  } catch (error) {
    console.error("Error resolving DID:", error);
  }
}

main().finally(() => client.close());

This code demonstrates how to:

Use the resolveDID function from the resolver package.
Fetch and display the DID document associated with a given DID string. This allows you to verify the authenticity and retrieve information linked to the DID.

Next Steps

Explore resolveDID: Dive deeper into the resolveDID function to understand its parameters, error handling, and advanced usage.
Manage DIDs: Learn how to use createDID, updateDID, and deactivateDID to effectively manage DIDs on Hedera.
Implement the Signer: Practice generating key pairs, signing messages, and verifying signatures using the Signer class.
Utilize the Publisher: Integrate the Publisher class into your application for seamless transaction submission.
Handling Exceptions: Explore best practices for handling exceptions and errors when working with the Hashgraph DID SDK: Handling Exceptions Guide.