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Version: 1.2

Getting Started with Wasm

Minimum Requirements​

Install the Library​

You can install the latest stable version of the library by running the following command:

npm install @iota/identity-wasm

Build the Library​

Alternatively, you can build the bindings yourself if you have Rust installed. If not, refer to rustup.rs for the installation.

Requirements​

1. Install wasm-bindgen-cli​

If you want to build the library from source, you will first need to manually install wasm-bindgen-cli. A manual installation is required because we use the Weak References feature, which wasm-pack does not expose.

cargo install --force wasm-bindgen-cli

2. Install Dependencies​

After installing wasm-bindgen-cli, you can install the necessary dependencies using the following command:

npm install

3. Build​

You can build the bindings for node.js using the following command:

npm run build:nodejs

NodeJS Usage​

The following code creates a new IOTA DID Document suitable for publishing to a local test network, like the IOTA Sandbox.

const {
  KeyPair,
  KeyType,
  MethodScope,
  IotaDocument,
  IotaVerificationMethod,
  IotaService,
  MethodRelationship,
  IotaIdentityClient,
} = require('@iota/identity-wasm/node');
const { Client } = require('@iota/client-wasm/node');

// The endpoint of the IOTA node to use.
const API_ENDPOINT = 'http://127.0.0.1:14265';

/** Demonstrate how to create a DID Document. */
async function main() {
  // Create a new client with the given network endpoint.
  const client = new Client({
    primaryNode: API_ENDPOINT,
    localPow: true,
  });

  const didClient = new IotaIdentityClient(client);

  // Get the Bech32 human-readable part (HRP) of the network.
  const networkHrp = await didClient.getNetworkHrp();

  // Create a new DID document with a placeholder DID.
  // The DID will be derived from the Alias Id of the Alias Output after publishing.
  const document = new IotaDocument(networkHrp);

  // Insert a new Ed25519 verification method in the DID document.
  let keypair = new KeyPair(KeyType.Ed25519);
  let method = new IotaVerificationMethod(
    document.id(),
    keypair.type(),
    keypair.public(),
    '#key-1',
  );
  document.insertMethod(method, MethodScope.VerificationMethod());

  // Attach a new method relationship to the existing method.
  document.attachMethodRelationship(
    document.id().join('#key-1'),
    MethodRelationship.Authentication,
  );

  // Add a new Service.
  const service = new IotaService({
    id: document.id().join('#linked-domain'),
    type: 'LinkedDomains',
    serviceEndpoint: 'https://iota.org/',
  });
  document.insertService(service);

  console.log(`Created document `, JSON.stringify(document.toJSON(), null, 2));
}

main();

Expected Output​

Created document  {
  "doc": {
    "id": "did:iota:0x0000000000000000000000000000000000000000000000000000000000000000",
    "verificationMethod": [
      {
        "id": "did:iota:0x0000000000000000000000000000000000000000000000000000000000000000#key-1",
        "controller": "did:iota:0x0000000000000000000000000000000000000000000000000000000000000000",
        "type": "Ed25519VerificationKey2018",
        "publicKeyMultibase": "z4SxypezRxr1YdMAJBePfHGxZ9hNZ53WVixZq3PbUcztW"
      }
    ],
    "authentication": [
      "did:iota:0x0000000000000000000000000000000000000000000000000000000000000000#key-1"
    ],
    "service": [
      {
        "id": "did:iota:0x0000000000000000000000000000000000000000000000000000000000000000#linked-domain",
        "type": "LinkedDomains",
        "serviceEndpoint": "https://iota.org/"
      }
    ]
  },
  "meta": {
    "created": "2022-09-09T11:29:32Z",
    "updated": "2022-09-09T11:29:32Z"
  }
}

Web Usage​

Set Up​

The library loads the WASM file with an HTTP GET request, so you must copy the .wasm file the root of the dist folder.

Rollup​

  • Install rollup-plugin-copy:
npm install rollup-plugin-copy --save-dev
  • Add the copy plugin usage to the plugins array under rollup.config.js:
// Include the copy plugin
import copy from 'rollup-plugin-copy';

// Add the copy plugin to the `plugins` array of your rollup config:
copy({
  targets: [
    {
      src: 'node_modules/@iota/client-wasm/web/wasm/client_wasm_bg.wasm',
      dest: 'public',
      rename: 'client_wasm_bg.wasm',
    },
    {
      src: 'node_modules/@iota/identity-wasm/web/identity_wasm_bg.wasm',
      dest: 'public',
      rename: 'identity_wasm_bg.wasm',
    },
  ],
});

Webpack​

  • Install copy-webpack-plugin:
npm install copy-webpack-plugin --save-dev
// Include the copy plugin
const CopyWebPlugin= require('copy-webpack-plugin');

// Add the copy plugin to the `plugins` array of your webpack config:

new CopyWebPlugin({
  patterns: [
    {
      from: 'node_modules/@iota/client-wasm/web/wasm/client_wasm_bg.wasm',
      to: 'client_wasm_bg.wasm'
    },
    {
      from: 'node_modules/@iota/identity-wasm/web/identity_wasm_bg.wasm',
      to: 'identity_wasm_bg.wasm'
    }
  ]
}),

Web Usage Example​

import * as client from '@iota/client-wasm/web';
import * as identity from '@iota/identity-wasm/web';

/** Demonstrate how to create a DID Document. */
async function createDocument() {
  // Create a new client with the given network endpoint.
  const iotaClient = new client.Client({
    primaryNode: API_ENDPOINT,
    localPow: true,
  });

  const didClient = new identity.IotaIdentityClient(iotaClient);

  // Get the Bech32 human-readable part (HRP) of the network.
  const networkHrp = await didClient.getNetworkHrp();

  // Create a new DID document with a placeholder DID.
  // The DID will be derived from the Alias Id of the Alias Output after publishing.
  const document = new identity.IotaDocument(networkHrp);

  // Insert a new Ed25519 verification method in the DID document.
  let keypair = new identity.KeyPair(identity.KeyType.Ed25519);
  let method = new identity.IotaVerificationMethod(
    document.id(),
    keypair.type(),
    keypair.public(),
    '#key-1',
  );
  document.insertMethod(method, identity.MethodScope.VerificationMethod());

  // Attach a new method relationship to the existing method.
  document.attachMethodRelationship(
    document.id().join('#key-1'),
    identity.MethodRelationship.Authentication,
  );

  // Add a new Service.
  const service = new identity.IotaService({
    id: document.id().join('#linked-domain'),
    type: 'LinkedDomains',
    serviceEndpoint: 'https://iota.org/',
  });
  document.insertService(service);

  console.log(`Created document `, JSON.stringify(document.toJSON(), null, 2));
}

client
  .init()
  .then(() => identity.init())
  .then(() => {
    await createDocument();
  });

// or

(async () => {
  await client.init();
  await identity.init();

  await createDocument();
})();

// Default path is "identity_wasm_bg.wasm", but you can override it like this
await identity.init('./static/identity_wasm_bg.wasm');

You need to call identity.init().then(<callback>), or await identity.init() to load the Wasm file from the server if not available, because of that it will only be slow for the first time.

Examples in the Wild​

You may find it useful to see how the WASM bindings are being used in existing applications:

API Reference​

Examples​