Iota Browser

Supported Languages

• TypeScript

npm install @affinidi-tdk/iota-browser --save

Implementation Note

The Iota Browser library is a browser-only module; make sure to invoke the library on the client side. It creates a WebSocket connection and requires access to the browser window object to initiate a data request to the Affinidi Vault.

If you are using a framework that has a server-side rendering like NextJS, you can do the following:

• Window Checking
• Dynamic Import

useEffect(() => {
    if (typeof window !== 'undefined') {
        const initIota = async () => {
            const iotaSession = new Session({ credentials: iotaCredentials });
            await iotaSession.initialize();

        }
        initIota()
    }
}

import dynamic from 'next/dynamic'

const IotaClientComponent = dynamic(() => import('components/Iota/IotaClientComponent'), {
  ssr: false,
})

export default function Page() {
  return <IotaClientComponent />
}

Classes and Methods

Session

Used to setup and manage the request to Affinidi Iota Framework. To initialise the Session, generate the Iota Credential using the iota-core package and pass the credential as a parameter.

const credentials = await getIotaCredentials(configurationId);
const iotaSession = new Session({ credentials });

The getIotaCredentials is an async function that calls an exposed API endpoint from the backend to generate the Iota Credentials.

initialize

Initialises the Iota Session, which opens a WebSocket that listens to callback events from the Affinidi Iota Framework service.

const iotaSession = new Session({ credentials })

await iotaSession.initialize()

prepareRequest

Creates the IotaRequest object from the initialised Iota Session. The response contains the signed Request Token for the Affinidi Vault to request data.

const request = await iotaSession.prepareRequest({ queryId })

IotaRequest

The class that initiates the data-sharing flow between the application and the Affinidi Vault is initialised from the prepareRequest method containing the signed Request Token.

openVault

Opens the Affinidi Vault with the signed Request Token and queries the data.

const iotaRequest = await iotaSession.prepareRequest({ queryId })

iotaRequest.openVault({ mode: openMode })

getResponse

Gets the response from the Affinidi Vault through the open WebSocket from the initialised Iota Session.

const iotaRequest = await iotaSession.prepareRequest({ queryId });
iotaRequest.openVault({ mode: openMode });

const response = await iotaRequest.getResponse();

Check for Iota Request Response

To check if Iota Request is a valid response and parse the Verifiable Presentation (verifiablePresentation), use the IotaResponse instance.

Example

• TypeScript

const iotaRequest = await iotaSession.prepareRequest({ queryId })
iotaRequest.openVault({ mode: openMode })

const response = await iotaRequest.getResponse()

if (response instanceof IotaResponse) {
    // parse the Verifiable Presentation and do business logic
}

Check for Iota Request Error

To check if there’s an error on the Iota Request and parse the relevant information about the error, use the IotaError instance.

Example

• TypeScript

try {
    const iotaCredentials = await getIotaCredentials();
    const iotaSession = new Session({ credentials: iotaCredentials });
    await iotaSession.initialize();
} catch (error) {
    if (error instanceof IotaError) {
        console.log(error.code);
    }
}